In order to ensure food safety,controlling foodborne pathogen contamination is of utmost importance.Growing apprehensions regarding the safety of synthetic antimicrobials,due to their adverse health effects,have promp...In order to ensure food safety,controlling foodborne pathogen contamination is of utmost importance.Growing apprehensions regarding the safety of synthetic antimicrobials,due to their adverse health effects,have prompted a search for alternative options.Plant natural products(PNPs)with antimicrobial activity are being explored as a viable alternative.Among the various antimicrobial natural products studied,plant essential oils,plant flavonoids,plant polyphenols,plant polysaccharides,and plant antimicrobial peptides have been identified as potential candidates.PNPs demonstrate a diverse array of antimicrobial mechanisms,encompassing cell wall and membrane damage,interference with genetic replication,disruption of energy metabolism,and induction of oxidative stress at the single-cell level,as well as inhibition of biofilm formation and quorum sensing at the population level.Certain PNPs have been harnessed as natural antimicrobial agents for the food preservation.The utilization of encapsulation technology proves to be an effective strategy in protecting PNPs,thereby ensuring good antimicrobial efficacy,enhanced dispersibility,and controlled release within food products.The utilization of nanoemulsions,nanoliposomes,edible packaging,electrospun nanofibers,and microcapsules formed by encapsulation has enriched the ways in which PNPs can be applied in food preservation.Although PNPs have great potential in food preservation,their widespread application in the food industry is currently constrained by factors such as production costs,safety concerns,and legal considerations.Chemical synthesis and biosynthesis pathways offer viable strategies for reducing the cost of producing PNPs,and ongoing efforts to assess safety and improve regulatory frameworks are likely to facilitate the broader adoption of PNPs in food preservation practices.This article provides an overview of the main types of PNPs with antimicrobial activity and their properties,focusing on their mechanisms of action.Additionally,it summarizes the use of PNPs in food preservation and discusses the characteristics and applications of different encapsulation technologies.Lastly,the paper briefly analyzes current limitations and proposes potential future trends for this field.展开更多
Two-dimensional(2D)nanomaterials have captured an increasing attention in biophotonics owing to their excellent optical features.Herein,2D hafnium ditelluride(HfTe_(2)),a new member of transition metal tellurides,is e...Two-dimensional(2D)nanomaterials have captured an increasing attention in biophotonics owing to their excellent optical features.Herein,2D hafnium ditelluride(HfTe_(2)),a new member of transition metal tellurides,is exploited to support gold nanoparticles fabricating HfTe_(2)-Au nanocomposites.The nanohybrids can serve as novel 2D surface-enhanced Raman scattering(SERS)substrate for the label-free detection of analyte with high sensitivity and reproducibility.Chemical mechanism originated from HfTe_(2) nanosheets and the electromagnetic enhancement induced by the hot spots on the nano-hybrids may largely contribute to the superior SERS effect of HfTe_(2)-Au nanocomposites.Finally,HfTe_(2)-Au nanocomposites are utilized for the label-free SERS analysis of foodborne pathogenic bac-teria,which realize the rapid and ultrasensitive Raman test of Escherichia coli,Listeria mono-cytogenes,Staphylococcus aureus and Salmonella with the limit of detection of 10 CFU/mL and the maximum Raman enhancement factor up to 1.7×10^(8).Combined with principal component analysis,HfTe_(2)-Au-based SERS analysis also completes the bacterial classification without extra treatment.展开更多
Background:Developing highly sensitive,simple,and rapid detection techniques for the accurate detection of foodborne pathogens is critical for food safety.This study designed a microfluidic chip integrating recombinas...Background:Developing highly sensitive,simple,and rapid detection techniques for the accurate detection of foodborne pathogens is critical for food safety.This study designed a microfluidic chip integrating recombinase polymerase amplification(RPA)and colloidal gold lateral chromatography for the visual detection of three high-risk foodborne pathogens:Escherichia coli O157:H7,Vibrio parahaemolyticus(VP),and Vibrio cholerae(VC).Methods:A lateral flow microfluidic chip was fabricated by integrating a chromatography test strip with a laser-ablated microfluidic structure.RPA primers targeting the rfbE gene of E.coli O157:H7,the toxR gene of VP,and the ctxA gene of V.cholerae were designed.The RPA products were validated by agarose gel electrophoresis,followed by optimization of the primer concentration,temperature,and reaction time.Results:The chip detected pathogens via RPA(at 40℃for 20 min)and a visual readout was obtained within 10 min,achieving 102 CFU/mL detection sensitivity for all three pathogens with high specificity,reproducibility,and stability.Conclusion:This microfluidic chip-based method enables portable on-site foodborne pathogen detection without the need for costly thermal cyclers/signal readers,thereby maintaining accuracy and affordability.展开更多
Foodborne pathogens cause diseases in humans.The traditional methods of detecting foodborne pathogens are time-consuming.The lateral flow immunoassay(LFIA)has become a widely used detection platform for onsite testing...Foodborne pathogens cause diseases in humans.The traditional methods of detecting foodborne pathogens are time-consuming.The lateral flow immunoassay(LFIA)has become a widely used detection platform for onsite testing of various foodborne pathogens due to its time-efficiency,cost-effectiveness,portability,and ease of use.With the development of novel nanomaterials,the sensitivity of the LFIA has improved tremendously compared with traditional colorimetric LFIA sensors.This review first summarizes the principles and corresponding formats of the LFIA.Then,a detailed classification of nanomaterial label(e.g.,metallic,carbon and selenium,fluorescent,and magnetic nanoparticles)synthesis,signal amplification strategy,and detection principles are discussed as related to food safety.Subsequently,the LFIA used in the detection of pathogenic bacteria,including Escherichia coli,Vibrio parahaemolyticus,Staphylococcus aureus,Listeria monocytogenes,and Salmonella,are classified and summarized.Multiple signal modes have been explored that improve the sensitivity of foodborne pathogen detection.Further improvement should focus on the design and preparation of high signal-to-noise ratio nanomaterials to achieve highly sensitive detection,and multitarget and multimode sensing.展开更多
Biofilms containing foodborne pathogens can adhere to food ingredients or food processing equipment.Due to their enhanced resilience to cleaning and chance of cross-contamination,there is an increased risk of food poi...Biofilms containing foodborne pathogens can adhere to food ingredients or food processing equipment.Due to their enhanced resilience to cleaning and chance of cross-contamination,there is an increased risk of food poisoning to consumers.The life course of biofilms is generally thought to be regulated by a quorum sensing(QS)system by secreted autoinducing peptides(AIPs).Recent studies have revealed that small non-coding RNA(sRNA)also plays an important role in regulating biofilm formation at the post-transcriptional level.Moreover,sRNA can act as an intermediate regulating hub between the quorum sensing system and biofilm.This review summarizes the latest findings on sRNA in biofilms of common foodborne pathogens and their potential impact.We also highlight the different mechanism of cascade regulation of sRNA and QS system in biofilm formation in several typical foodborne pathogens.In this process,sRNA responds to dynamic external environmental signals finely and accurately,and can feedback information on the bacterial cell environment to modify the QS system.These findings will deepen our understanding of biofilm formation and provide new perspectives for eliminating biofilm of foodborne pathogens based on the cascade regulation of small RNA and QS for developing biofilm-free food-processing systems.展开更多
Objectives:Growing trend of street-vended food in underdeveloped countries offers low-cost food to many sections of population.Although it provides job opportunities to many urban dwellers,several health hazards are a...Objectives:Growing trend of street-vended food in underdeveloped countries offers low-cost food to many sections of population.Although it provides job opportunities to many urban dwellers,several health hazards are associated with this business.The present study investigates the burden of foodborne pathogens in Ready-To-Eat(RTE)beverages in relation to vending practices among street vendors of Rawalpindi City,Pakistan according to standardized methods and protocols.Materials and Methods:Six densely populated locations of Rawalpindi city were selected.Commonly consumed sugar cane juice(SCJ)and tamarind prune(dried plums)drink(TPD)(locally called as Imli Alu Bukhara sherbet)from five vendors from each location were chosen in summer season where the temperature reaches above 40℃.Mean and the standard deviation were obtained by univariate and bivariate analyses.Association between the study variables was assessed through cross-tabulations,chi-square,and correlation tests.Results:All the samples were found unsatisfactory in comparison to guidelines of aerobic plate count.Total coliform was observed in 86.7 per cent of SCJ and 70.0 per cent of TPD samples.Fourteen samples of SCJ exceeded the limit of>1100 MPN/ml value,whereas samples of TPD exceeded this limit for Escherichia coli.All of SCJ and 93.3 per cent of TPD samples depicted the presence of Salmonella aureus.Salmonella spp.were found significantly high in 73.3 per cent samples of SCJ and 23.3 per cent samples of TPD.Conclusions:The incidence of high bioloads attributes towards a potential reservoir of foodborne pathogens due to unhygienic vending practices.展开更多
Objective: To refine the infectious doses of enteric bacterial pathogens in animal assays and vaccine clinical trials by studying the invasion kinetics of five bacterial pathogens with human intestinal cells.Methods: ...Objective: To refine the infectious doses of enteric bacterial pathogens in animal assays and vaccine clinical trials by studying the invasion kinetics of five bacterial pathogens with human intestinal cells.Methods: Utilizing in vitro cultured cell invasion assays with gentamicin-killing step,the invasive effects were analyzed in foodborne pathogens including Salmonella,Shigella, Yersinia, Escherichia coli(E. coli) O157 and opportunistic pathogens Citrobacter in human embryonic intestine 407 cells and ileocecum HCT-8 cells at multiplicities of infection(MOIs) of 0.04–4 000.00 E. coli HS served as a noninvasive control.Results: The study results showed that the bacterial invasive efficiency and the average number of internalized bacteria per host cell changed with different starting MOIs. Higher starting MOIs did not always produce more bacterial internalization. The bacterial invasion effects varied with different bacterial strains and host cell lines. E. coli O157:H7 did invade human ileocecum HCT-8 cells.Conclusions: This study shows that these bacteria possess different invasive patterns at various starting MOIs and also in different cell lines. The results could help to figure out the appropriate infectious doses of the bacteria in animal assays and in vaccine clinical trials. The bacterial invasion kinetics is also valuable in evaluating the safety and efficacy of live attenuated bacterial vaccines.展开更多
Intestinal infections affect approximately 450 million people globally,predominantly impacting children and immunocompromised individuals in lowand middle-income countries(LMICs)due to inadequate water,sanitation,and ...Intestinal infections affect approximately 450 million people globally,predominantly impacting children and immunocompromised individuals in lowand middle-income countries(LMICs)due to inadequate water,sanitation,and hygiene(WASH)conditions,poverty,malnutrition,and low literacy.In Kenya,the prevalence of intestinal infections is elevated by warm tropical climates and socioeconomic factors.This scoping review evaluates the national prevalence,risk factors,and contamination sources of intestinal protozoa in Kenya,using a One Health approach to synthesize existing data from various human,animal,and environmental studies.A comprehensive literature search identified 292 studies,of which 67 met the inclusion criteria,covering the period from 1966 to 2024.The review found that most studies utilized stool microscopy,a method with limited sensitivity,and largely focused on vulnerable human populations,with minimal investigation into environmental reservoirs.Key protozoa identified included Entamoeba histolytica,Cryptosporidium,and Giardia,with transmission driven by poor WASH conditions,environmental factors,and close humananimal interactions.The findings highlight significant gaps in environmental surveillance and suggest the need for a robust,integrated One Health approach to better understand and control protozoan infections in Kenya.展开更多
Sustainability is a leading trend in the context of food production.Additionally,consumers increasingly demand safer and less-processed products.Among the different technologies used to maintain the quality and extend...Sustainability is a leading trend in the context of food production.Additionally,consumers increasingly demand safer and less-processed products.Among the different technologies used to maintain the quality and extend the shelf-life of fresh and minimally-processed food,natural antimicrobial agents offer a promising strategy to replace conventional compounds.In this regard,phage lytic proteins or lysins,such as endolysins and virion-associated peptidoglycan hydrolases(VAPGHs),have been proposed as a viable option for the avoidance and elimination of undesirable bacteria within the food production chain.Even when applied exogenously,these proteins can degrade the bacterial cell wall maintaining their lytic activity.This feature,alongside their modular structure,which can be exploited for bioengineering,provides significant biotechnological potential.However,despite the promising properties of lysins,the main obstacle for their commercialization is the limited legal information regulating their use.This challenge underscores the need to navigate complex regulatory pathways.The primary objective of this review is to address this crucial gap and summarize the many prospective applications of endolysins during the different stages of food production.By doing so,we aim to provide clarity and insight into the regulatory challenges that must be overcome for the successful utilization of lysins.展开更多
Listeria monocytogenes is an important foodborne pathogen responsible for listeriosis,a fatal disease.It is widely distributed in various foods and environmental sources.In this review,we focused on addressing PCR-bas...Listeria monocytogenes is an important foodborne pathogen responsible for listeriosis,a fatal disease.It is widely distributed in various foods and environmental sources.In this review,we focused on addressing PCR-based technologies,including conventional PCR,qPCR and droplet digital PCR(ddPCR).Specifically,we described(a)conventional PCR and mono-,duplex-and multiplex-qPCR methodologies;(b)development and applications of gene HlyA-,Iap-,PrfA–and SsrA-based conventional and qPCR assays as well as PCR assays targeting newly identified gene targets for specific detection of L.monocytogenes;differentiation of viable from dead L.monocytogenes by qPCR in conjugation with propidium monoazide pretreatment;PCR-based serotype identification of L.monocytogenes isolates;PCR-based detection of L.ivanovii,infecting ruminants,differentiation of L.monocytogenes from other Listeria species;and sigB-gene based PCR identification of Listeria spp;(c)applications of ddPCR in detection of L.monocytogenes;and(d)application of qPCR assays in detection and subtyping of L.monocytogenes in milk and dairy products;meats,meat products and meat-processing environment;and seafood,seafood products and processing environment.Our goal was to provide a relatively comprehensive overview of PCR-based methodologies available in detection,characterization and subtyping of various strains of L.monocytogenes in foods and environmental sources.展开更多
Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and in...Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.展开更多
This study aimed to assess the microbiological quality of 159 animal-and plant-based ready-to-cook(RTC)frozen food items currently popular in Dhaka.Microbiological analyses were carried out to enumerate total aerobic ...This study aimed to assess the microbiological quality of 159 animal-and plant-based ready-to-cook(RTC)frozen food items currently popular in Dhaka.Microbiological analyses were carried out to enumerate total aerobic counts of mesophilic bacteria,yeast and mold and to detect some common foodborne pathogens according to standard microbiological criteria.Higher microbial loads in all animal-based food types,other than chicken strips were found.In contrast,plant-based items were relatively safe except paratha,dal-puri,rooti chapati,and aloo-puri.Several common pathogenic bacterial species were screened by analyzing their morphological,cultural,and biochemical characteristics.Escherichia coli was prevalent in most samples,while Salmonella species were least reported.A considerable number of samples exhibited enough microbial loads at infection or intoxication levels.展开更多
Staphylococcus aureus is a common marine foodborne pathogen.In this study,antibiotics ciprofloxacin and enrofloxacin were used to induce drug-resistance in S.aureus.The differentially expressed proteins(DEPs)were anal...Staphylococcus aureus is a common marine foodborne pathogen.In this study,antibiotics ciprofloxacin and enrofloxacin were used to induce drug-resistance in S.aureus.The differentially expressed proteins(DEPs)were analyzed and compared with those in the bacteria cultured without antibiotics.The primary proteomic alterations were in the levels of cell membrane components and proteins related to lysine and folic acid biosynthesis,which were all significantly up-regulated.The minimal inhibitory concentrations(MIC)for both test drugs were elevated to 10μg m L^(-1)following serial passaging.These results indicated that,for both ciprofloxacin and enrofloxacin,drug-resistance were developed even in the subinhibitory levels and the primary response was a major alteration in the cell membrane proteome.These changes were similar to those observed in S.aureus cultured with super-MIC levels of these antibiotics.The current study provides a theoretical basis for in-depth study of the related changes of marine foodborne pathogens in subinhibitory concentrations that are commonly found in situ.展开更多
The study focused on analysis and evaluation of microbial contamination of raw beef was designed to （1） determine the presence of foodborne pathogens in raw beef; （2） compare the prevalence of microbial contaminat...The study focused on analysis and evaluation of microbial contamination of raw beef was designed to （1） determine the presence of foodborne pathogens in raw beef; （2） compare the prevalence of microbial contamination among the three supermarkets, and （3） evaluate the sanitary quality of raw beef products. Also, six kind of microorganisms including Total Plate Count, Total Coliform and Fecal Coliform, which represented sanitary quality and E. coli, S. Aureus and B. cereus, which determined the presence of foodborne pathogens, were analyzed. The procedures used to analyse experimental samples taken from three supermarket （in every one week for three weeks） in Phnom Penh were based on Merck＇s study in 2005. The results had shown that there were no significant differences in Total Plate Counts, Total Coliform and Fecal Coliform in all samples, and they were found in unacceptable numbers in the raw beef products. However, the prevalence of foodborne pathogens including E. coli, S. aureus and B. cereus were found in acceptable numbers. Furthermore, the samples taken from the second supermarket had the highest level of microbial contamination among the three supermarkets, while the samples taken from the first supermarket had the lowest level of microbial contamination. This experimental finding demonstrated the need for sanitary improvement in the beef retails markets and strict sanitary guideline and implementation of these practices could guarantee consumers＇ health by consuming raw beefs with the lowest risk of foodborne pathogens.展开更多
Food-producing animals are the major reservoirs for many foodborne pathogens such as Campylobacter species, non-Typhi serotypes of Salmonella enterica, Shiga toxin-producing strains of Escherichia coli, and Listeria m...Food-producing animals are the major reservoirs for many foodborne pathogens such as Campylobacter species, non-Typhi serotypes of Salmonella enterica, Shiga toxin-producing strains of Escherichia coli, and Listeria monocytogenes. The zoonotic potential of foodborne pathogens and their ability to produce toxins causing diseases or even death are sufficient to recognize the seriousness of the situation. This manuscript reviews the evidence that links animals as vehicles of the foodborne pathogens Salmonella,Campylobacter, Shiga toxigenic E. coli, and L. monocytogenes, their impact, and their current status. We conclude that these pathogenic bacteria will continue causing outbreaks and deaths throughout the world, because no effective interventions have eliminated them from animals and food.展开更多
Many current studies on rapid detection of pathogenic bacteria in foods have focused on the construction of detection methods,neglecting pretreatment.It is also a key step to efficiently elute pathogenic bacteria from...Many current studies on rapid detection of pathogenic bacteria in foods have focused on the construction of detection methods,neglecting pretreatment.It is also a key step to efficiently elute pathogenic bacteria from food samples for rapid detection and can even determine the success or failure of an assay.In this study,we used Escherichia coli(E.coli),Salmonella enteritidis(S.enteritidis),and Listeria monocytogenes(L.monocytogenes)as model bacteria to compare the elution efficiency of different eluants;explore the effect of surfactant,ionic strength,protein(or amino acid and peptide),and enzyme on the recovery rate of bacteria in lettuce;and compare the compound effect caused by multiple factors.Finally,we developed an efficient bacterial recovery method and confirmed the superiority of this method to analyze the bacterial diversity of eluants from lettuce.The results showed that the recovery efficiency of E.coli,S.enteritidis,and L.monocytogenes,which were artificially contaminated with approximately 10^(5)CFU/g in lettuces,could reach 94.4%,90.6%,and 93.7%by using 10 mmol/L Tris·HCl(pH 9.5)with 0.1%peptone and 300 U/100 mL of cellulase,and furthermore,the elution efficiency could reach 99.6%,98.6%,and 100%with the aid of a 2-min stomaching.For the lettuce samples with only native bacteria,the recovery rate reached 92.1%for viable aerobic bacteria by this method,which was approximately 10%higher than that of the modified previous method.The bacterial diversity of the eluted solution was analyzed,and the result was significantly improved.Considering these advantages,it is important to improve the elution efficiency to achieve rapid and accurate detection of pathogenic bacteria in lettuces.展开更多
Objectives:Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis,which causes human eosinophilic meningitis.There is a lack of data confirming the relevance of fish in A...Objectives:Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis,which causes human eosinophilic meningitis.There is a lack of data confirming the relevance of fish in A.cantonensis life cycle and their contribution to human infection.Materials and Methods:We conducted a series of experiments to investigate the survival and infectivity of A.cantonensis larvae in Clarias gariepinus(catfish;n=30)and Oreochromis niloticus(tilapia;n=24).Each fish was inoculated with 10000 third-stage larvae(L3).Larval survival was assessed through artificial digestion of fish tissues 1 week,2 weeks,and 3 weeks post-infection.To investigate the early stages of infection,four catfish were inoculated with 10000 L3 each and sacrificed 3 d post-infection.Quantitative polymerase chain reaction(qPCR)analysis and histopathological examination were performed to evaluate larval distribution and tissue reactions.Two infected catfish,sacrificed 1 week post-infection,were used to feed Wistar rats.Results:After 45 d,the rats did not shed first-stage larvae(L1),indicating the absence of infection.One week post-infection,dead larvae were present in the digested tissues of both fish species,and the same was observed 2 weeks and 3 weeks after exposure.qPCR analysis revealed that the intestine was the most heavily infected organ.Histopathological examination identified dead larvae within granulomas in both the intestines and liver.Early-stage infection experiment showed that fish sacrificed 3 d post-inoculation contained viable L3,which was infective to Wistar rats.Conclusions:While A.cantonensis L3 can survive and remain infective in fish for a short period,they typically die within first few days postinfection.This suggests that fish may not be significant long-term paratenic hosts for A.cantonensis but may play a temporary role in its transmission to mammals(including humans)and birds.These results are consistent with previous studies on freshwater shrimps and highlight the importance of understanding aquatic host interactions in the epidemiology of this zoonotic foodborne pathogen.展开更多
Objectives:This study aimed to investigate microbial contamination in seafood-contacted ice,with a particular focus on the prevalence of pathogenic bacteria,antimicrobial resistance of isolates,and bacterial diversity...Objectives:This study aimed to investigate microbial contamination in seafood-contacted ice,with a particular focus on the prevalence of pathogenic bacteria,antimicrobial resistance of isolates,and bacterial diversity.Materials and Methods:Seafood-contacted ice samples were collected from 12 districts in Shanghai,China,during August and September 2023.The sanitary conditions were assessed using Plate Count Agar(PCA)and Violet Red Bile Agar(VRBA)plates for serial dilution and plating.Microbial prevalence was determined by streaking on selective agar plates.Antimicrobial susceptibility of the isolates was evaluated using the disk diffusion method.Bacterial diversity was analyzed using the Illumina high-throughput sequencing platform.Results:The results revealed that the total plate count in the samples ranged from 1.89 to 5.94 log colony-forming units(CFU)/mL,with an average of 4.15 log CFU/mL.Coliform counts were present in 98.50%of the samples,with counts ranging from 0.70 to 4.06 log CFU/mL,with an average of 2.05 log CFU/mL.Pathogenic bacteria detected included Vibrio parahaemolyticus in 31 samples(31/200,15.50%),Escherichia coli in 16 samples(16/200,8.00%),and Staphylococcus aureus in nine samples(9/200,4.50%).V.parahaemolyticus showed a high ampicillin resistance rate of 96.8%(30/31).E.coli exhibited general resistance to most antibiotics.S.aureus isolates demonstrated greater resistance to ampicillin(6/9,66.7%),but remained sensitive to other antibiotics.High-throughput sequencing has demonstrated that certain microorganisms exhibit resistance to low temperature through mechanisms such as bioflm formation,contributing to their pathogenicity and posing a threat to the safety of seafood-contacted ice.Specifcally,Pseudomonas,Aeromonas,and Shewanella should be prioritized in future preventive and control measures.Conclusions:The sanitary conditions of seafood-contacted ice in Shanghai are concerned.Certain bacteria exhibit high detection rates and signifcant antimicrobial resistance,while some microorganisms capable of surviving at low temperature pose a serious threat to the safety of these products.展开更多
Listeria monocytogenes(L.monocytogenes),a foodborne pathogen,can cause human listeriosis.Listeriosis is a potentially fatal gastrointestinal illness,which is closely related to the spread of food to humans.We review t...Listeria monocytogenes(L.monocytogenes),a foodborne pathogen,can cause human listeriosis.Listeriosis is a potentially fatal gastrointestinal illness,which is closely related to the spread of food to humans.We review the literature published during 2010-2019 to better understand the prevalence of L.monocytogenes in food products,incidence of human listeriosis,and their characteristics in Chinese mainland.We found the main sequence types(STs)strains from foods are similar globally,and the prevalence of L.monocytogenes from raw meat was the highest among all food products.The most common STs in food products and clinical cases were ST9(serogroup I.2)strains and ST87(serogroup Il.2)strains,respectively.The ST87 strains being the most common STs of clinical cases might be related to the existence of Listeria pathogenicity island 4 gene and Chinese eating habits for ready-to-eat foods,among which the prevalence of ST87 strain was the highest in ready-to-eat foods.Therefore,more research should be conducted to explore the reasons for the L.monocytogenes isolates differences in food and clinical sources.展开更多
This study investigated antibacterial and antibiofilm activity of the combined use of phenyllactic acid(PLA)and bacteriocin XJS01 against Shigella flexneri_14.The minimum inhibitory concentration(MIC)of PLA and XJS01 ...This study investigated antibacterial and antibiofilm activity of the combined use of phenyllactic acid(PLA)and bacteriocin XJS01 against Shigella flexneri_14.The minimum inhibitory concentration(MIC)of PLA and XJS01 against S.flexneri_14 was 2.45 mg/mL and 18.75μg/mL,respectively.Growth and kill kinetics assays showed that the combined use of 1/2MIC PLA plus 1/2MIC XJS01 had a better activity against planktonic S.flexneri_14 compared to treatment with PLA and XJS01 used singly(1/2MIC and 2MIC).Cellular biochemical and morphological analysis revealed the remarkable ability of the combination in disrupting cell appearance and promoting deformation of planktonic S.flexneri_14 compared to single use.Moreover,S.flexneri_14 biofilm formation was inhibited and degraded by the combination,which showed a more remarkable antibiofilm activity than PLA and XJS01 when used singly.This study demonstrates the synergistic antibacterial activity of PLA and XJS01 against S.flexneri_14 in either planktonic or biofilm states in foods.展开更多
基金supported by the National Natural Science Foundation of China(32060520)Science and Technology Talents and Platform Program of Yunnan Province(202105AF150049)University Key Laboratory of Food Microbial Resources and Utilization in Yunnan Province(Yunjiaofa[2018]No.135).
文摘In order to ensure food safety,controlling foodborne pathogen contamination is of utmost importance.Growing apprehensions regarding the safety of synthetic antimicrobials,due to their adverse health effects,have prompted a search for alternative options.Plant natural products(PNPs)with antimicrobial activity are being explored as a viable alternative.Among the various antimicrobial natural products studied,plant essential oils,plant flavonoids,plant polyphenols,plant polysaccharides,and plant antimicrobial peptides have been identified as potential candidates.PNPs demonstrate a diverse array of antimicrobial mechanisms,encompassing cell wall and membrane damage,interference with genetic replication,disruption of energy metabolism,and induction of oxidative stress at the single-cell level,as well as inhibition of biofilm formation and quorum sensing at the population level.Certain PNPs have been harnessed as natural antimicrobial agents for the food preservation.The utilization of encapsulation technology proves to be an effective strategy in protecting PNPs,thereby ensuring good antimicrobial efficacy,enhanced dispersibility,and controlled release within food products.The utilization of nanoemulsions,nanoliposomes,edible packaging,electrospun nanofibers,and microcapsules formed by encapsulation has enriched the ways in which PNPs can be applied in food preservation.Although PNPs have great potential in food preservation,their widespread application in the food industry is currently constrained by factors such as production costs,safety concerns,and legal considerations.Chemical synthesis and biosynthesis pathways offer viable strategies for reducing the cost of producing PNPs,and ongoing efforts to assess safety and improve regulatory frameworks are likely to facilitate the broader adoption of PNPs in food preservation practices.This article provides an overview of the main types of PNPs with antimicrobial activity and their properties,focusing on their mechanisms of action.Additionally,it summarizes the use of PNPs in food preservation and discusses the characteristics and applications of different encapsulation technologies.Lastly,the paper briefly analyzes current limitations and proposes potential future trends for this field.
基金supported by the National Natural Science Foundation of China(11874021,61675072 and 21505047)the Science and Technology Project of Guangdong Province of China(2017A020215059)+2 种基金the Science and Technology Project of Guangzhou City(201904010323 and 2019050001)the Innovation Project of Graduate School of South China Normal University School(2019LKXM023)the Natural Science Research Project of Guangdong Food and Drug Vocational College(2019ZR01)
文摘Two-dimensional(2D)nanomaterials have captured an increasing attention in biophotonics owing to their excellent optical features.Herein,2D hafnium ditelluride(HfTe_(2)),a new member of transition metal tellurides,is exploited to support gold nanoparticles fabricating HfTe_(2)-Au nanocomposites.The nanohybrids can serve as novel 2D surface-enhanced Raman scattering(SERS)substrate for the label-free detection of analyte with high sensitivity and reproducibility.Chemical mechanism originated from HfTe_(2) nanosheets and the electromagnetic enhancement induced by the hot spots on the nano-hybrids may largely contribute to the superior SERS effect of HfTe_(2)-Au nanocomposites.Finally,HfTe_(2)-Au nanocomposites are utilized for the label-free SERS analysis of foodborne pathogenic bac-teria,which realize the rapid and ultrasensitive Raman test of Escherichia coli,Listeria mono-cytogenes,Staphylococcus aureus and Salmonella with the limit of detection of 10 CFU/mL and the maximum Raman enhancement factor up to 1.7×10^(8).Combined with principal component analysis,HfTe_(2)-Au-based SERS analysis also completes the bacterial classification without extra treatment.
基金funded by a Scientific Research Project from the Hunan Provincial Department of Education(23C0201)the Excellent Youth Program of Hunan Provincial Department of Education(23B0561)the Natural Science Foundation of Hunan Province(2024JJ7137,2024JJ7133).
文摘Background:Developing highly sensitive,simple,and rapid detection techniques for the accurate detection of foodborne pathogens is critical for food safety.This study designed a microfluidic chip integrating recombinase polymerase amplification(RPA)and colloidal gold lateral chromatography for the visual detection of three high-risk foodborne pathogens:Escherichia coli O157:H7,Vibrio parahaemolyticus(VP),and Vibrio cholerae(VC).Methods:A lateral flow microfluidic chip was fabricated by integrating a chromatography test strip with a laser-ablated microfluidic structure.RPA primers targeting the rfbE gene of E.coli O157:H7,the toxR gene of VP,and the ctxA gene of V.cholerae were designed.The RPA products were validated by agarose gel electrophoresis,followed by optimization of the primer concentration,temperature,and reaction time.Results:The chip detected pathogens via RPA(at 40℃for 20 min)and a visual readout was obtained within 10 min,achieving 102 CFU/mL detection sensitivity for all three pathogens with high specificity,reproducibility,and stability.Conclusion:This microfluidic chip-based method enables portable on-site foodborne pathogen detection without the need for costly thermal cyclers/signal readers,thereby maintaining accuracy and affordability.
基金This work is financially supported by the National Natural Science Foundation of China(22236002)Science and Technology Project of Jiangsu Market Supervision Administration(SZSJ2022001).
文摘Foodborne pathogens cause diseases in humans.The traditional methods of detecting foodborne pathogens are time-consuming.The lateral flow immunoassay(LFIA)has become a widely used detection platform for onsite testing of various foodborne pathogens due to its time-efficiency,cost-effectiveness,portability,and ease of use.With the development of novel nanomaterials,the sensitivity of the LFIA has improved tremendously compared with traditional colorimetric LFIA sensors.This review first summarizes the principles and corresponding formats of the LFIA.Then,a detailed classification of nanomaterial label(e.g.,metallic,carbon and selenium,fluorescent,and magnetic nanoparticles)synthesis,signal amplification strategy,and detection principles are discussed as related to food safety.Subsequently,the LFIA used in the detection of pathogenic bacteria,including Escherichia coli,Vibrio parahaemolyticus,Staphylococcus aureus,Listeria monocytogenes,and Salmonella,are classified and summarized.Multiple signal modes have been explored that improve the sensitivity of foodborne pathogen detection.Further improvement should focus on the design and preparation of high signal-to-noise ratio nanomaterials to achieve highly sensitive detection,and multitarget and multimode sensing.
基金This work was supported by National Natural Science Foundation of China(32272424)Guangdong Major Project of Basic and Applied Basic Research(2020B0301030005)+1 种基金Guangdong Provincial Key Laboratory(2020B121201009)Guangdong Academy of Sciences Special Project for Capacity Building of Innovation Driven Development(2020GDASYL-20200401002).
文摘Biofilms containing foodborne pathogens can adhere to food ingredients or food processing equipment.Due to their enhanced resilience to cleaning and chance of cross-contamination,there is an increased risk of food poisoning to consumers.The life course of biofilms is generally thought to be regulated by a quorum sensing(QS)system by secreted autoinducing peptides(AIPs).Recent studies have revealed that small non-coding RNA(sRNA)also plays an important role in regulating biofilm formation at the post-transcriptional level.Moreover,sRNA can act as an intermediate regulating hub between the quorum sensing system and biofilm.This review summarizes the latest findings on sRNA in biofilms of common foodborne pathogens and their potential impact.We also highlight the different mechanism of cascade regulation of sRNA and QS system in biofilm formation in several typical foodborne pathogens.In this process,sRNA responds to dynamic external environmental signals finely and accurately,and can feedback information on the bacterial cell environment to modify the QS system.These findings will deepen our understanding of biofilm formation and provide new perspectives for eliminating biofilm of foodborne pathogens based on the cascade regulation of small RNA and QS for developing biofilm-free food-processing systems.
基金supported by Higher Education Commission of Pakistan(grant PM IPFP/HRD/HEC/2011/353).
文摘Objectives:Growing trend of street-vended food in underdeveloped countries offers low-cost food to many sections of population.Although it provides job opportunities to many urban dwellers,several health hazards are associated with this business.The present study investigates the burden of foodborne pathogens in Ready-To-Eat(RTE)beverages in relation to vending practices among street vendors of Rawalpindi City,Pakistan according to standardized methods and protocols.Materials and Methods:Six densely populated locations of Rawalpindi city were selected.Commonly consumed sugar cane juice(SCJ)and tamarind prune(dried plums)drink(TPD)(locally called as Imli Alu Bukhara sherbet)from five vendors from each location were chosen in summer season where the temperature reaches above 40℃.Mean and the standard deviation were obtained by univariate and bivariate analyses.Association between the study variables was assessed through cross-tabulations,chi-square,and correlation tests.Results:All the samples were found unsatisfactory in comparison to guidelines of aerobic plate count.Total coliform was observed in 86.7 per cent of SCJ and 70.0 per cent of TPD samples.Fourteen samples of SCJ exceeded the limit of>1100 MPN/ml value,whereas samples of TPD exceeded this limit for Escherichia coli.All of SCJ and 93.3 per cent of TPD samples depicted the presence of Salmonella aureus.Salmonella spp.were found significantly high in 73.3 per cent samples of SCJ and 23.3 per cent samples of TPD.Conclusions:The incidence of high bioloads attributes towards a potential reservoir of foodborne pathogens due to unhygienic vending practices.
文摘Objective: To refine the infectious doses of enteric bacterial pathogens in animal assays and vaccine clinical trials by studying the invasion kinetics of five bacterial pathogens with human intestinal cells.Methods: Utilizing in vitro cultured cell invasion assays with gentamicin-killing step,the invasive effects were analyzed in foodborne pathogens including Salmonella,Shigella, Yersinia, Escherichia coli(E. coli) O157 and opportunistic pathogens Citrobacter in human embryonic intestine 407 cells and ileocecum HCT-8 cells at multiplicities of infection(MOIs) of 0.04–4 000.00 E. coli HS served as a noninvasive control.Results: The study results showed that the bacterial invasive efficiency and the average number of internalized bacteria per host cell changed with different starting MOIs. Higher starting MOIs did not always produce more bacterial internalization. The bacterial invasion effects varied with different bacterial strains and host cell lines. E. coli O157:H7 did invade human ileocecum HCT-8 cells.Conclusions: This study shows that these bacteria possess different invasive patterns at various starting MOIs and also in different cell lines. The results could help to figure out the appropriate infectious doses of the bacteria in animal assays and in vaccine clinical trials. The bacterial invasion kinetics is also valuable in evaluating the safety and efficacy of live attenuated bacterial vaccines.
基金Supported by the National Key Research and Development Program of China(2022YFC3204703)the China Postdoctoral Innovation Talents Support Program(BX20230400).
文摘Intestinal infections affect approximately 450 million people globally,predominantly impacting children and immunocompromised individuals in lowand middle-income countries(LMICs)due to inadequate water,sanitation,and hygiene(WASH)conditions,poverty,malnutrition,and low literacy.In Kenya,the prevalence of intestinal infections is elevated by warm tropical climates and socioeconomic factors.This scoping review evaluates the national prevalence,risk factors,and contamination sources of intestinal protozoa in Kenya,using a One Health approach to synthesize existing data from various human,animal,and environmental studies.A comprehensive literature search identified 292 studies,of which 67 met the inclusion criteria,covering the period from 1966 to 2024.The review found that most studies utilized stool microscopy,a method with limited sensitivity,and largely focused on vulnerable human populations,with minimal investigation into environmental reservoirs.Key protozoa identified included Entamoeba histolytica,Cryptosporidium,and Giardia,with transmission driven by poor WASH conditions,environmental factors,and close humananimal interactions.The findings highlight significant gaps in environmental surveillance and suggest the need for a robust,integrated One Health approach to better understand and control protozoan infections in Kenya.
基金funded by grants PID2019-105311RB-I00(MICIU/AEI/FEDER,UE,Spain)to P.García and A.RodríguezAYUD/2021/52120(Program of Science,Technology and Innovation 2021-2023 and FEDER EU,Principado de Asturias,Spain)。
文摘Sustainability is a leading trend in the context of food production.Additionally,consumers increasingly demand safer and less-processed products.Among the different technologies used to maintain the quality and extend the shelf-life of fresh and minimally-processed food,natural antimicrobial agents offer a promising strategy to replace conventional compounds.In this regard,phage lytic proteins or lysins,such as endolysins and virion-associated peptidoglycan hydrolases(VAPGHs),have been proposed as a viable option for the avoidance and elimination of undesirable bacteria within the food production chain.Even when applied exogenously,these proteins can degrade the bacterial cell wall maintaining their lytic activity.This feature,alongside their modular structure,which can be exploited for bioengineering,provides significant biotechnological potential.However,despite the promising properties of lysins,the main obstacle for their commercialization is the limited legal information regulating their use.This challenge underscores the need to navigate complex regulatory pathways.The primary objective of this review is to address this crucial gap and summarize the many prospective applications of endolysins during the different stages of food production.By doing so,we aim to provide clarity and insight into the regulatory challenges that must be overcome for the successful utilization of lysins.
文摘Listeria monocytogenes is an important foodborne pathogen responsible for listeriosis,a fatal disease.It is widely distributed in various foods and environmental sources.In this review,we focused on addressing PCR-based technologies,including conventional PCR,qPCR and droplet digital PCR(ddPCR).Specifically,we described(a)conventional PCR and mono-,duplex-and multiplex-qPCR methodologies;(b)development and applications of gene HlyA-,Iap-,PrfA–and SsrA-based conventional and qPCR assays as well as PCR assays targeting newly identified gene targets for specific detection of L.monocytogenes;differentiation of viable from dead L.monocytogenes by qPCR in conjugation with propidium monoazide pretreatment;PCR-based serotype identification of L.monocytogenes isolates;PCR-based detection of L.ivanovii,infecting ruminants,differentiation of L.monocytogenes from other Listeria species;and sigB-gene based PCR identification of Listeria spp;(c)applications of ddPCR in detection of L.monocytogenes;and(d)application of qPCR assays in detection and subtyping of L.monocytogenes in milk and dairy products;meats,meat products and meat-processing environment;and seafood,seafood products and processing environment.Our goal was to provide a relatively comprehensive overview of PCR-based methodologies available in detection,characterization and subtyping of various strains of L.monocytogenes in foods and environmental sources.
文摘Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.
文摘This study aimed to assess the microbiological quality of 159 animal-and plant-based ready-to-cook(RTC)frozen food items currently popular in Dhaka.Microbiological analyses were carried out to enumerate total aerobic counts of mesophilic bacteria,yeast and mold and to detect some common foodborne pathogens according to standard microbiological criteria.Higher microbial loads in all animal-based food types,other than chicken strips were found.In contrast,plant-based items were relatively safe except paratha,dal-puri,rooti chapati,and aloo-puri.Several common pathogenic bacterial species were screened by analyzing their morphological,cultural,and biochemical characteristics.Escherichia coli was prevalent in most samples,while Salmonella species were least reported.A considerable number of samples exhibited enough microbial loads at infection or intoxication levels.
基金funded by the Professional Innovation and Integration Project of Qingdao University(2020)。
文摘Staphylococcus aureus is a common marine foodborne pathogen.In this study,antibiotics ciprofloxacin and enrofloxacin were used to induce drug-resistance in S.aureus.The differentially expressed proteins(DEPs)were analyzed and compared with those in the bacteria cultured without antibiotics.The primary proteomic alterations were in the levels of cell membrane components and proteins related to lysine and folic acid biosynthesis,which were all significantly up-regulated.The minimal inhibitory concentrations(MIC)for both test drugs were elevated to 10μg m L^(-1)following serial passaging.These results indicated that,for both ciprofloxacin and enrofloxacin,drug-resistance were developed even in the subinhibitory levels and the primary response was a major alteration in the cell membrane proteome.These changes were similar to those observed in S.aureus cultured with super-MIC levels of these antibiotics.The current study provides a theoretical basis for in-depth study of the related changes of marine foodborne pathogens in subinhibitory concentrations that are commonly found in situ.
文摘The study focused on analysis and evaluation of microbial contamination of raw beef was designed to （1） determine the presence of foodborne pathogens in raw beef; （2） compare the prevalence of microbial contamination among the three supermarkets, and （3） evaluate the sanitary quality of raw beef products. Also, six kind of microorganisms including Total Plate Count, Total Coliform and Fecal Coliform, which represented sanitary quality and E. coli, S. Aureus and B. cereus, which determined the presence of foodborne pathogens, were analyzed. The procedures used to analyse experimental samples taken from three supermarket （in every one week for three weeks） in Phnom Penh were based on Merck＇s study in 2005. The results had shown that there were no significant differences in Total Plate Counts, Total Coliform and Fecal Coliform in all samples, and they were found in unacceptable numbers in the raw beef products. However, the prevalence of foodborne pathogens including E. coli, S. aureus and B. cereus were found in acceptable numbers. Furthermore, the samples taken from the second supermarket had the highest level of microbial contamination among the three supermarkets, while the samples taken from the first supermarket had the lowest level of microbial contamination. This experimental finding demonstrated the need for sanitary improvement in the beef retails markets and strict sanitary guideline and implementation of these practices could guarantee consumers＇ health by consuming raw beefs with the lowest risk of foodborne pathogens.
文摘Food-producing animals are the major reservoirs for many foodborne pathogens such as Campylobacter species, non-Typhi serotypes of Salmonella enterica, Shiga toxin-producing strains of Escherichia coli, and Listeria monocytogenes. The zoonotic potential of foodborne pathogens and their ability to produce toxins causing diseases or even death are sufficient to recognize the seriousness of the situation. This manuscript reviews the evidence that links animals as vehicles of the foodborne pathogens Salmonella,Campylobacter, Shiga toxigenic E. coli, and L. monocytogenes, their impact, and their current status. We conclude that these pathogenic bacteria will continue causing outbreaks and deaths throughout the world, because no effective interventions have eliminated them from animals and food.
基金supported by Shanghai‘Science and Technology Innovation Action Plan’for Agriculture Project(19391902100,21N31901100)the Special Project on Agricultural Science and Technology Innovation—Applied Basic Research Project of Shanghai Academy of Agricultural Sciences(Agricultural Science Application Foundation 2022-09),China.
文摘Many current studies on rapid detection of pathogenic bacteria in foods have focused on the construction of detection methods,neglecting pretreatment.It is also a key step to efficiently elute pathogenic bacteria from food samples for rapid detection and can even determine the success or failure of an assay.In this study,we used Escherichia coli(E.coli),Salmonella enteritidis(S.enteritidis),and Listeria monocytogenes(L.monocytogenes)as model bacteria to compare the elution efficiency of different eluants;explore the effect of surfactant,ionic strength,protein(or amino acid and peptide),and enzyme on the recovery rate of bacteria in lettuce;and compare the compound effect caused by multiple factors.Finally,we developed an efficient bacterial recovery method and confirmed the superiority of this method to analyze the bacterial diversity of eluants from lettuce.The results showed that the recovery efficiency of E.coli,S.enteritidis,and L.monocytogenes,which were artificially contaminated with approximately 10^(5)CFU/g in lettuces,could reach 94.4%,90.6%,and 93.7%by using 10 mmol/L Tris·HCl(pH 9.5)with 0.1%peptone and 300 U/100 mL of cellulase,and furthermore,the elution efficiency could reach 99.6%,98.6%,and 100%with the aid of a 2-min stomaching.For the lettuce samples with only native bacteria,the recovery rate reached 92.1%for viable aerobic bacteria by this method,which was approximately 10%higher than that of the modified previous method.The bacterial diversity of the eluted solution was analyzed,and the result was significantly improved.Considering these advantages,it is important to improve the elution efficiency to achieve rapid and accurate detection of pathogenic bacteria in lettuces.
基金supported by the Southeast Asia-Europe Joint Funding Scheme for Research and Innovation(SEAEUROPEJFS19IN-053)the Czech Science Foundation(No.22-26136S)Elena Izquierdo-Rodriguez was supported by the M-ULL scholarship(M-ULL,convocatoria 2019),Czech Republic.The work of Lucia Anettováwas also supported by the Czech Academy of Sciences,ABERA Project.
文摘Objectives:Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis,which causes human eosinophilic meningitis.There is a lack of data confirming the relevance of fish in A.cantonensis life cycle and their contribution to human infection.Materials and Methods:We conducted a series of experiments to investigate the survival and infectivity of A.cantonensis larvae in Clarias gariepinus(catfish;n=30)and Oreochromis niloticus(tilapia;n=24).Each fish was inoculated with 10000 third-stage larvae(L3).Larval survival was assessed through artificial digestion of fish tissues 1 week,2 weeks,and 3 weeks post-infection.To investigate the early stages of infection,four catfish were inoculated with 10000 L3 each and sacrificed 3 d post-infection.Quantitative polymerase chain reaction(qPCR)analysis and histopathological examination were performed to evaluate larval distribution and tissue reactions.Two infected catfish,sacrificed 1 week post-infection,were used to feed Wistar rats.Results:After 45 d,the rats did not shed first-stage larvae(L1),indicating the absence of infection.One week post-infection,dead larvae were present in the digested tissues of both fish species,and the same was observed 2 weeks and 3 weeks after exposure.qPCR analysis revealed that the intestine was the most heavily infected organ.Histopathological examination identified dead larvae within granulomas in both the intestines and liver.Early-stage infection experiment showed that fish sacrificed 3 d post-inoculation contained viable L3,which was infective to Wistar rats.Conclusions:While A.cantonensis L3 can survive and remain infective in fish for a short period,they typically die within first few days postinfection.This suggests that fish may not be significant long-term paratenic hosts for A.cantonensis but may play a temporary role in its transmission to mammals(including humans)and birds.These results are consistent with previous studies on freshwater shrimps and highlight the importance of understanding aquatic host interactions in the epidemiology of this zoonotic foodborne pathogen.
基金supported by the Project of the China National Center for Food Safety Risk Assessment,2023the Natural Science Foundation of Shanghai(No.22ZR1427500),China.
文摘Objectives:This study aimed to investigate microbial contamination in seafood-contacted ice,with a particular focus on the prevalence of pathogenic bacteria,antimicrobial resistance of isolates,and bacterial diversity.Materials and Methods:Seafood-contacted ice samples were collected from 12 districts in Shanghai,China,during August and September 2023.The sanitary conditions were assessed using Plate Count Agar(PCA)and Violet Red Bile Agar(VRBA)plates for serial dilution and plating.Microbial prevalence was determined by streaking on selective agar plates.Antimicrobial susceptibility of the isolates was evaluated using the disk diffusion method.Bacterial diversity was analyzed using the Illumina high-throughput sequencing platform.Results:The results revealed that the total plate count in the samples ranged from 1.89 to 5.94 log colony-forming units(CFU)/mL,with an average of 4.15 log CFU/mL.Coliform counts were present in 98.50%of the samples,with counts ranging from 0.70 to 4.06 log CFU/mL,with an average of 2.05 log CFU/mL.Pathogenic bacteria detected included Vibrio parahaemolyticus in 31 samples(31/200,15.50%),Escherichia coli in 16 samples(16/200,8.00%),and Staphylococcus aureus in nine samples(9/200,4.50%).V.parahaemolyticus showed a high ampicillin resistance rate of 96.8%(30/31).E.coli exhibited general resistance to most antibiotics.S.aureus isolates demonstrated greater resistance to ampicillin(6/9,66.7%),but remained sensitive to other antibiotics.High-throughput sequencing has demonstrated that certain microorganisms exhibit resistance to low temperature through mechanisms such as bioflm formation,contributing to their pathogenicity and posing a threat to the safety of seafood-contacted ice.Specifcally,Pseudomonas,Aeromonas,and Shewanella should be prioritized in future preventive and control measures.Conclusions:The sanitary conditions of seafood-contacted ice in Shanghai are concerned.Certain bacteria exhibit high detection rates and signifcant antimicrobial resistance,while some microorganisms capable of surviving at low temperature pose a serious threat to the safety of these products.
基金supported by the National Key Research and Development Program of China (No.2019YFE0103800).
文摘Listeria monocytogenes(L.monocytogenes),a foodborne pathogen,can cause human listeriosis.Listeriosis is a potentially fatal gastrointestinal illness,which is closely related to the spread of food to humans.We review the literature published during 2010-2019 to better understand the prevalence of L.monocytogenes in food products,incidence of human listeriosis,and their characteristics in Chinese mainland.We found the main sequence types(STs)strains from foods are similar globally,and the prevalence of L.monocytogenes from raw meat was the highest among all food products.The most common STs in food products and clinical cases were ST9(serogroup I.2)strains and ST87(serogroup Il.2)strains,respectively.The ST87 strains being the most common STs of clinical cases might be related to the existence of Listeria pathogenicity island 4 gene and Chinese eating habits for ready-to-eat foods,among which the prevalence of ST87 strain was the highest in ready-to-eat foods.Therefore,more research should be conducted to explore the reasons for the L.monocytogenes isolates differences in food and clinical sources.
基金supported by Yunnan Fundamental Research Projects(Grant No.202101BE070001-046)the Natural Science Foundation of China(31960286).
文摘This study investigated antibacterial and antibiofilm activity of the combined use of phenyllactic acid(PLA)and bacteriocin XJS01 against Shigella flexneri_14.The minimum inhibitory concentration(MIC)of PLA and XJS01 against S.flexneri_14 was 2.45 mg/mL and 18.75μg/mL,respectively.Growth and kill kinetics assays showed that the combined use of 1/2MIC PLA plus 1/2MIC XJS01 had a better activity against planktonic S.flexneri_14 compared to treatment with PLA and XJS01 used singly(1/2MIC and 2MIC).Cellular biochemical and morphological analysis revealed the remarkable ability of the combination in disrupting cell appearance and promoting deformation of planktonic S.flexneri_14 compared to single use.Moreover,S.flexneri_14 biofilm formation was inhibited and degraded by the combination,which showed a more remarkable antibiofilm activity than PLA and XJS01 when used singly.This study demonstrates the synergistic antibacterial activity of PLA and XJS01 against S.flexneri_14 in either planktonic or biofilm states in foods.
