Root rot is a prevalent soil-borne fungal disease in citrus.Citron C-05(Citrus medica)stands out as a germplasm within Citrus spp.due to its complete resistance to citrus canker and favorable characteristics such as s...Root rot is a prevalent soil-borne fungal disease in citrus.Citron C-05(Citrus medica)stands out as a germplasm within Citrus spp.due to its complete resistance to citrus canker and favorable characteristics such as single embryo and easy rooting.However,Citron C-05 was found to be highly susceptible to root rot during cultivation,with the specific pathogens previously unknown.In this study,four candidate fungal species were isolated from Citron C-05 roots.Sequence analysis of ITS,EF-1a,RPB1,and RPB2 identified two Fusarium solani strains,Rr-2 and Rr-4,as the candidates causing root rot in Citron C-05.Resistance tests showed these two pathogens increased root damage rate from 10.30%to 35.69%in Citron C-05,sour orange(Citrus aurantium),sweet orange(Citrus sinensis)and pummelo(Citrus grandis).F.solani exhibited the weak pathogenicity towards trifoliate orange(Poncirus trifoliata).DAB staining revealed none of reddish-brown precipitation in the four susceptible citrus germplasm after infection with F.solani,while trifoliate orange exhibited significant H2O2 accumulation.Trypan blue staining indicated increased cell death in the four susceptible citrus germplasm following infection with these two pathogens but not in trifoliate orange.These findings provide a comprehensive understanding of citrus root rot and support future research on the mechanisms of root rot resistance in citrus.展开更多
Reductive soil disinfestation(RSD)is commonly employed for soil remediation in greenhouse cultivation.However,its influence on antibiotic resistance genes(ARGs)in soil remains uncertain.This study investigated the dyn...Reductive soil disinfestation(RSD)is commonly employed for soil remediation in greenhouse cultivation.However,its influence on antibiotic resistance genes(ARGs)in soil remains uncertain.This study investigated the dynamic changes in soil communities,potential bacterial pathogens,and ARG profiles under various organicmaterial treatments during RSD,including distillers’grains,potato peel,peanut vine,and peanut vine combined with charcoal.Results revealed that applying diverse organic materials in RSD significantly altered bacterial community composition and diminished the relative abundance of potential bacterial pathogens(P<0.05).The relative abundance of high-risk ARGs decreased by 10.7%-30.6%after RSD treatments,the main decreased ARG subtypeswere AAC(3)_Via,dfrA1,ErmB,lnuB,aadA.Actinobacteria was the primary host of ARGs and was suppressed by RSD.Soil physicochemical properties,such as total nitrogen,soil pH,total carbon,were crucial factors affecting ARG profiles.Our findings demonstrated that RSD treatment inhibited pathogenic bacteria and could be an option for reducing high-risk ARG proliferation in soil.展开更多
The sustainable development of aquaculture industry is deeply constrained by pathogens and diseases,and traditional detection methods are difficult to adapt to the needs of intensive aquaculture due to low efficiency ...The sustainable development of aquaculture industry is deeply constrained by pathogens and diseases,and traditional detection methods are difficult to adapt to the needs of intensive aquaculture due to low efficiency and insufficient sensitivity.This article reviews the progress of rapid detection technology for aquatic pathogens based on molecular biology,immunology,biosensors,etc.,and analyzes the application value of innovative methods such as isothermal amplification and CRISPR.This technology injects core momentum into the new quality productivity of fisheries through early and precise identification of pathogens:reducing aquaculture losses to improve resource efficiency,promoting the transformation of aquaculture models to data-driven,ensuring the safety of aquatic products to enhance the competitiveness of the industry chain.The current technology has shortcomings such as lagging standardization,weak on-site anti-interference ability,and insufficient recognition of new pathogens.In the future,we need to focus on technological integration and innovation,intelligent upgrading,and standardization construction,promote technology from laboratories to industrial applications,and provide continuous support for the high-quality development of fisheries.展开更多
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
Detection and monitoring of pathogens is a central aspect of maintaining public health.Rare and neglected zoonotic viruses have the potential to evolve and expand exponentially,leading to unforeseen outbreaks,epidemic...Detection and monitoring of pathogens is a central aspect of maintaining public health.Rare and neglected zoonotic viruses have the potential to evolve and expand exponentially,leading to unforeseen outbreaks,epidemics,and pandemics.The emerging multiomics and meta-omics techniques and workflows,such as proteogenomics and meta-genomics,offer the potential for the detection of harmful pathogens,as well as opportunities for the discovery of previously unknown bacterial,parasitic,or viral pathogens.Multiomics and meta-omics workflows provide molecular information for tracking pathogens and understanding the effectiveness of spread mitigation strategies.In addition to environmental monitoring,multiomics and meta-omics approaches have the potential for clinical applications and in-depth characterization of novel pathogens.In this review,we discuss recent applications of multiomics and meta-omics techniques,their advantages over traditional methods,and their potential implementations in biomedical research,environmental studies,and healthcare.We critically assess the benefits and challenges of multiomics and meta-omics studies and discuss their future perspectives.展开更多
Respiratory infections are associated with high morbidity and mortality and are a major global health problem[1].Acute respiratory infections are caused by multiple respiratory pathogens,including viruses and bacteria...Respiratory infections are associated with high morbidity and mortality and are a major global health problem[1].Acute respiratory infections are caused by multiple respiratory pathogens,including viruses and bacteria.Viral-bacterial co-infections,which have become increasingly common and a global concern,can lead to substantial complications,causing higher morbidity and adverse prognosis[2].Previous studies have reported low positive detection rates of targeted pathogens related to acute respiratory infections,owing to the limited number of detected pathogens and variations in the sensitivity of diagnostic methods[3-4].Low positive detection rates may impede our understanding of respiratory pathogen characteristics and hamper the development of precise treatment and prevention strategies.展开更多
The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a mol...The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a molding process,which enables the batch detection of pathogens.It explores the rapid lysis and elution processes of pathogens within the microfluidic chips to ensure that nucleic acid extraction,elution,and amplification are completed entirely within the chip.This chip can extract nucleic acids from samples in just 10 min,achieving an extraction efficiency comparable to that of traditional in-tube methods.An oil phase is pre-loaded into the chip to effectively prevent aerosol contamination.This approach allows for the simultaneous detection of 21 common respiratory pathogens,with a detection limit of 10 copies per reaction.Furthermore,applications involving clinical samples demonstrate significant practicality.Compared to many traditional in-tube pathogen detection methods and molecular biology technologies that utilize microfluidic chips,this detection chip not only enables simultaneous detection of multiple pathogens but also demonstrates high sensitivity.展开更多
The apoplast is a critical interface where plants and pathogens engage in biochemical confrontation.Within this shared extracellular space,plant defense responses provoke countermeasures from pathogens.We introduce ap...The apoplast is a critical interface where plants and pathogens engage in biochemical confrontation.Within this shared extracellular space,plant defense responses provoke countermeasures from pathogens.We introduce apoplastic interactive balance(AIB),a framework depicting the dynamic equilibrium that emerges from these interactions.AIB emphasizes that system-level functional stability arises from both balanced and divergent molecular strategies,with transient imbalances driving coevolutionary refinement.These interactions are classified into four modules:metabolites,proteins,small peptides,and extracellular vesicles(EVs).Across these modules,plants and pathogens deploy parallel molecular tactics shaped by adaptive coevolution.This conceptual view provides a foundation for hypothesis generation,comparative analysis among species,and the design of rational immune strategies.展开更多
NADC34-like porcine reproductive and respiratory syndrome virus(PRRSV),which first appeared in China in 2017,is currently one of the main epidemic strains in China.In this study,we found that a new variant of NADC34-l...NADC34-like porcine reproductive and respiratory syndrome virus(PRRSV),which first appeared in China in 2017,is currently one of the main epidemic strains in China.In this study,we found that a new variant of NADC34-like PRRSV evolved,named the L1A variant.The phylogenetics,epidemic status,and pathogenicity of the LA variants were subsequently comprehensively evaluated.Based on the results of the ORF5 phylogenetic analysis,the L1A variants were classified as NADC34-like PPRSV.All the strains had the same discontinuous 131-aa deletion in the NSP2 region(similar to that in the NADC30).Recombination analysis revealed that the L1A variants were recombinant viruses that contained an NADC30-like PRRSV skeleton,a nonstructural protein-encoding gene region obtained in part from JXA1-like PRRSV and a ORF2-ORF6 gene region partly obtained from NADC34-like PRRSV and that exhibited similar recombination patterns.We successfully isolated the L1A variant TZJ2756 from PAMs and Marc-145 cells.In animal experiments,TZJ2756 exhibited moderate pathogenicity in piglets,causing obvious clinical symptoms,namely,persistent fever,significantly reduced body weight,interstitial edema and severe interstitial pneumonia in the lungs,and prolonged high-load viremia.L1A variants have been detected in at least 12 provinces in China and share many similar epidemiological characteristics with the American L1C variant.This research will enhance our understanding of the prevalence of L1A variants and furnish valuable data for the ongoing monitoring of NADC34-like PRRSV in China.展开更多
Staphylococcus aureus(S.aureus)is the third most common pathogen causing 10.6%of bacterial foodborne illnesses in China in 2021[1].Heat-stable Staphylococcal Enterotoxins(SEs)produced by S.aureus are the main contribu...Staphylococcus aureus(S.aureus)is the third most common pathogen causing 10.6%of bacterial foodborne illnesses in China in 2021[1].Heat-stable Staphylococcal Enterotoxins(SEs)produced by S.aureus are the main contributors to staphylococcal food poisoning(SFP),causing vomiting,diarrhea,abdominal pain,headache,muscle cramps,and other acute gastroenteritis symptoms.More than 25 SEs and staphylococcal enterotoxin-like toxins(SE/s)have been described and which together comprise a superfamily of pyrogenic toxin superantigens(SAgs)[2].展开更多
Multiple sclerosis is a severe autoimmune disorder that is mainly mediated by pathogenic cluster of CD4^(+)T cell subsets.Despite advancements in the management of multiple sclerosis,there is a critical need for more ...Multiple sclerosis is a severe autoimmune disorder that is mainly mediated by pathogenic cluster of CD4^(+)T cell subsets.Despite advancements in the management of multiple sclerosis,there is a critical need for more effective and safer treatments.In the present study,we administered Lycium barbarum glycopeptide to a mouse model of experimental autoimmune encephalomyelitis-an animal model of multiple sclerosis-and evaluated its effects on pathogenic CD4^(+)T cell activation both in vivo and in vitro.Lycium barbarum glycopeptide significantly mitigated the clinical severity of experimental autoimmune encephalomyelitis,as demonstrated by reduced demyelination and neuroinflammation.Moreover,Lycium barbarum glycopeptide treatment decreased the infiltration of peripheral leukocytes into the central nervous system and suppressed pro-inflammatory cytokine expression.Lycium barbarum glycopeptide also modulated pathogenic CD4^(+)T cell activation by inhibiting T helper 1/T helper 17 cell differentiation while promoting regulatory T cell expansion.Notably,no side effects were observed,suggesting the long-term safety and tolerability of Lycium barbarum glycopeptide.Furthermore,RNA sequencing data indicated that Lycium barbarum glycopeptide inhibits activator protein-1,an essential regulator of T cell activation and differentiation.This finding was supported by the reversal of T helper/T helper 17 cell response suppression upon AP-1 blockade.Collectively,these results highlight the potential of Lycium barbarum glycopeptide as an innovative therapeutic agent for CD4^(+)T cell-associated autoimmune or inflammatory diseases,such as multiple sclerosis.展开更多
The pathogens and opinion for antibiotic treatment in adult patients with 1-14 fecal white blood cells per high power field （WBC/HPF） of acute non-bloody diarrhea remain obscure. The study attempts to clarify it. St...The pathogens and opinion for antibiotic treatment in adult patients with 1-14 fecal white blood cells per high power field （WBC/HPF） of acute non-bloody diarrhea remain obscure. The study attempts to clarify it. Stool specimens of adult patients with acute non-bloody diarrhea and stool examination showing 1-14 fecal WBC/HPF were collected for bacterial culture and viral detection. Patients included in this study were 196 cases with mean age of （37.9±17.4） years and 42.3% was women. The bacterial and viral detection rates were 63 （32.1%） and 21 （10.7%）, respectively. Of the isolated pathogens, campylobacteria was present in 14 （22.0%） samples and was the most common bacteria and calicivirus was found in 10 （47.6%） samples and was the most common virus. Based on single pathogens, 46 cases were caused by invasive pathogens, 26 cases were caused by non-invasive pathogens. The body temperature was significantly higher in feverish patients caused by invasive pathogens than those caused by non-invasive pathogens （（38.44-0.7） ℃ vs （37.74-0.4） ℃, P = 0.002）. The probability of diarrhea caused by invasive pathogens was higher in patients with T〉38.4℃ than those with T_〈38.4℃ （RR = 1.5）. When T〉38.4℃ is used as the threshold for antibiotic treatment, the misuse rate of antibiotics would decrease from 26.9% to 3.8% （P = 0.021）. So T〉38.4 ℃ may be used as a possible reference value for antibiotic treatment in adult patients with 1-14 fecal WBC/HPF of acute non-bloody diarrhea.展开更多
[Objective] The aim of this study was to purify an antimicrobial protein from a biocontrol bacterium strain K2-1 and analyze its antimicrobial activity in vitro against some typical aquatic pathogens. [Method] The ant...[Objective] The aim of this study was to purify an antimicrobial protein from a biocontrol bacterium strain K2-1 and analyze its antimicrobial activity in vitro against some typical aquatic pathogens. [Method] The antimicrobial protein was ob- tained by using ammonium sulfate precipitation and Sephadex chromatography combined with hot water bath. The antimicrobial assay was conducted by means of agar diffusion technique, using Vibrio alginolyticus, Aeromonas hydrophila, Aeromonas. Sobria, Pseudomonas fluorescens, Vibrio Parahaemolyticus, Vibrio har- veyi and Vibrio anguillarum as test bacteria. [Result] Antimicrobial protein APK2 can be derived from fermentation broth of strain K2-1 and purified to the chromatogra- phy pure level by the methods provided, the final yield of the antimicrobial compo- nent is approximately 0.08%. This antimicrobial protein had a strong antimicrobial activity against the growth of most those bacteria. [Conclusion] The results show that APK2 could be a potential alternative to replace chemical antimicrobial agent in the control and prevention of aquatic diseases.展开更多
The effects of O3/Cl2 disinfection on corrosion and the growth of opportunistic pathogens in drinking water distribution systems were studied using annular reactors （ARs）. The corrosion process and most probable num...The effects of O3/Cl2 disinfection on corrosion and the growth of opportunistic pathogens in drinking water distribution systems were studied using annular reactors （ARs）. The corrosion process and most probable number （MPN） analysis indicated that the higher content of iron-oxidizing bacteria and iron-reducing bacteria in biofilms of the AR treated with O3/Cl2 induced higher Fe304 formation in corrosion scales. These corrosion scales became more stable than the ones that formed in the AR treated with Cl2 alone. O3/Cl2 disinfection inhibited corrosion and iron release efficiently by changing the content of corrosion-related bacteria. Moreover, ozone disinfection inactivated or damaged the opportunistic pathogens due to its strong oxidizing properties. The damaged bacteria resulting from initial ozone treatment were inactivated by the subsequent chlorine disinfection. Compared with the AR treated with Cl2 alone, the opportunistic pathogens M. auium and L. pneumophila were not detectable in effluents of the AR treated with O3/Cl2, and decreased to （4.60 ± 0.14） and （3.09 ± 0.12） loglo （gene copies/g corrosion scales） in biofilms, respectively. The amoeba counts were also lower in the AR treated with O3/Cl2. Therefore, O3/Cl2 disinfection can effectively control opportunistic pathogens in effluents and biofilms of an AR used as a model for a drinking water distribution system.展开更多
The importance of pyrimidines lies in the fact that they are structural components of a broad spectrum of key molecules that participate in diverse cellular functions, such as synthesis of DNA, RNA, lipids, and carboh...The importance of pyrimidines lies in the fact that they are structural components of a broad spectrum of key molecules that participate in diverse cellular functions, such as synthesis of DNA, RNA, lipids, and carbohydrates. Pyrimidine metabolism encompasses all enzymes involved in the synthesis, degradation, salvage, interconversion and transport of these molecules. In this review, we summarize recent publications that document how pyrimidine metabolism changes under a variety of conditions, including, when possible, those studies based on techniques of genomics, transcriptomics, proteomics, and metabolomics. First, we briefly look at the dynamics of pyrimidine metabolism during nonpathogenic cellular events. We then focus on changes that pathogen infections cause in the pyrimidine metabolism of their host. Next, we discuss the effects of antimetabolites and inhibitors, and finally we consider the consequences of genetic ma- nipulations, such as knock-downs, knock-outs, and knock-ins, of pyrimidine enzymes on pyrimidine metabolism in the cell.展开更多
The emergence and prevalence of antibiotic resistance genes(ARGs) and pathogens in the environment are serious global health concern. However, information about the occurrence of ARGs and pathogens in recreational wat...The emergence and prevalence of antibiotic resistance genes(ARGs) and pathogens in the environment are serious global health concern. However, information about the occurrence of ARGs and pathogens in recreational water is still limited. Accordingly, we investigated the occurrence of six ARGs and human pathogens in three recreational lakes, and the correlations between ARGs and one mobile genetic element(intI1) were analyzed. The quantitative PCR results showed that the concentration of ARGs ranged from 4.58 × 10~0 to 5.0 × 10~5 copies/mL in water and from 5.78 × 10~3 to 5.89 × 10~8 copies/g dry weight(dw)in sediment. Sul1 exhibited the highest level among the five quantifiable ARGs. The concentrations of sul1, bla_(-TEM), and tetX exhibited significant positive correlations with intI1(p < 0.05), indicating that intI1 may be involved in their proliferation. The detection frequencies of ARGs ranged from 75%–10~0%, indicating the prevalence of these risks in this region. The concentration of Escherichia coli, Aeromonas spp., Mycobacterium avium,Pseudomonas aeruginosa, and Salmonella enterica ranged from 10~3 to 10~5 copies/10~0 mL in water and 10~4–10~6 copies/g dw in sediment. In total, 25% of the samples harbored all pathogen genes, indicating the prevalence of these pathogens in recreational lakes.Furthermore, the next-generation sequencing results showed that 68 genera of pathogens were present, among which Aeromonas, Mycobacterium, and Pseudomonas were the dominant ones in this region, posing a considerable potential health risk to public health. Overall, the widespread distribution of ARGs and pathogens underscores the need to better monitor and mitigate their propagation in recreational lakes and the associated risks to human health.展开更多
Plant pathogens have evolved numerous strategies to obtain nutritive materials from their host, and plants in turn have evolved the preformed physical and chemical barriers as well as sophisticated two-tiered immune s...Plant pathogens have evolved numerous strategies to obtain nutritive materials from their host, and plants in turn have evolved the preformed physical and chemical barriers as well as sophisticated two-tiered immune system to combat pathogen attacks. Genetically, plant resistance to pathogens can be divided into qualitative and quantitative disease resistance, conditioned by major gene（s） and multiple genes with minor effects, respectively. Qualitative disease resistance has been mostly detected in plant defense against biotrophic pathogens, whereas quantitative disease resistance is involved in defense response to all plant pathogens, from biotrophs, hemibiotrophs to necrotrophs. Plant resistance is achieved through interception of pathogen-derived effectors and elicitation of defense response. In recent years, great progress has been made related to the molecular basis underlying host--pathogen interactions. In this review, we would like to provide an update on genetic and molecular aspects of plant resistance to pathogens.展开更多
Due to increasing regulations and restrictions, there is an urgent need to develop effective alternatives to chemical-dependent fumigation control of soilborne pests and pathogens. Anaerobic soil disinfestation （ASD...Due to increasing regulations and restrictions, there is an urgent need to develop effective alternatives to chemical-dependent fumigation control of soilborne pests and pathogens. Anaerobic soil disinfestation （ASD） is one such alternative showing great promise for use in the control of soilborne pathogens and pests. This method involves the application of a carbon source, irrigation to field capacity, and covering the soil with a plastic tarp. While the mechanisms of ASD are not completely understood, they appear to be a combination of changes in the soil microbial community composition, production of volatile organic compounds, and the generation of lethal anaerobic conditions. The variety of materials and options for ASD application, including carbon sources, soil temperature, and plastic tarp type, influence the efficacy of pathogen sup- pression and disease control. Currently, both dry （e.g., rice bran） and liquid （e.g., ethanol） carbon sources are commonly used, but with different results depending on environmental conditions. While solarization is not an essential component of ASD, it can enhance efficacy. Understanding the mechanisms that mediate biological changes occurring in the soil during ASD will facilitate our ability to increase ASD efficacy while enhancing its commercial viability.展开更多
Spontaneous bacterial peritonitis(SBP) is the most typical infection observed in cirrhosis patients. SBP is responsible for an in-hospital mortality rate of approximately 32%. Recently, pattern changes in the bacteria...Spontaneous bacterial peritonitis(SBP) is the most typical infection observed in cirrhosis patients. SBP is responsible for an in-hospital mortality rate of approximately 32%. Recently, pattern changes in the bacterial flora of cirrhosis patients have been observed, and an increase in the prevalence of infections caused by multi-resistant bacteria has been noted. The wide-scale use of quinolones in the prophylaxis of SBP has promoted flora modifications and resulted in the development of bacterial resistance. The efficacy of traditionally recommended therapy has been low in nosocomial infections(up to 40%), and multi-resistance has been observed in up to 22% of isolated germs in nosocomial SBP. For this reason, the use of a broad empirical spectrum antibiotic has been suggested in these situations. The distinction between community-acquired infectious episodes, healthcare-associated infections, or nosocomial infections, and the identification of risk factors for multi-resistant germs can aid in the decision-making process regarding the empirical choice of antibiotic therapy. Broad-spectrum antimicrobial agents, such as carbapenems with or without glycopeptides or piperacillin-tazobactam, should be considered for the initial treatment not only of nosocomial infections but also of healthcare-associated infections when the risk factors or severity signs for multi-resistant bacteria are apparent. The use of cephalosporins should be restricted to community-acquired infections.展开更多
Objective:To determine the prevalence and antimicrobial resistance rates of nosocomial pathogens isolated from cancer patients and hospital environments.Methods:A descriptive cross-sectional study was conducted betwee...Objective:To determine the prevalence and antimicrobial resistance rates of nosocomial pathogens isolated from cancer patients and hospital environments.Methods:A descriptive cross-sectional study was conducted between December 2010 to May 2013 at Radiation and Isotopes Centre of Khartoum,Sudan.A total of 1 503 samples(505 clinical and 998 environmental)were examined.Isolates were identified,and their antimicrobial susceptibility was determined using standard laboratory procedures.Results:Out of 505 clinical samples,nosocomial pathogens were found as 48.1%.Among hospital environment samples,bacterial contaminants were detected in 29.7%of samples.The main microorganisms recovered from cancer patients were Proteus spp.(23.5%),Escherichia coli(22.2%),Pseudomonas aeruginosa(P.aeruginosa)(21.0%)and Staphylococcus aureus(20.2%).The most frequent isolates from hospital environments were Bacillus spp.(50.0%),Staphylococcus aureus(14.2%)and P.aeruginosa(11.5%).The proportions of resistance among Gram-negative pathogens from cancer patients were high for ampicillin,cefotaxime,ceftazidime and ceftriaxone.Moderate resistance rates were recorded to ciprofloxacin,such as 51.0%for P.aeruginosa,21.7%for Klebsiella pneumoniae and 55.5%for Escherichia coli.Except Klebsiella,there were no significant differences(P0.05)of resistance rates between Gram-negative isolates from cancer patients to those from the hospital environments.The proportions of extended-spectrum b-lactamase producing isolates from cancer patients were not differ significantly(P=0.763)from those collected from the hospital environments(49.2%;91/185 vs.47%;32/68).Conclusions:The prevalence of nosocomial infection among cancer patients was high(48.1%)with the increasing of antimicrobial resistance rates.Hospital environments are potential reservoirs for nosocomial infections,which calls for intervention program to reduce environmental transmission of pathogens.展开更多
基金supported by Joint Funds of the National Natural Science Foundation of China(Grant No.U21A20228).
文摘Root rot is a prevalent soil-borne fungal disease in citrus.Citron C-05(Citrus medica)stands out as a germplasm within Citrus spp.due to its complete resistance to citrus canker and favorable characteristics such as single embryo and easy rooting.However,Citron C-05 was found to be highly susceptible to root rot during cultivation,with the specific pathogens previously unknown.In this study,four candidate fungal species were isolated from Citron C-05 roots.Sequence analysis of ITS,EF-1a,RPB1,and RPB2 identified two Fusarium solani strains,Rr-2 and Rr-4,as the candidates causing root rot in Citron C-05.Resistance tests showed these two pathogens increased root damage rate from 10.30%to 35.69%in Citron C-05,sour orange(Citrus aurantium),sweet orange(Citrus sinensis)and pummelo(Citrus grandis).F.solani exhibited the weak pathogenicity towards trifoliate orange(Poncirus trifoliata).DAB staining revealed none of reddish-brown precipitation in the four susceptible citrus germplasm after infection with F.solani,while trifoliate orange exhibited significant H2O2 accumulation.Trypan blue staining indicated increased cell death in the four susceptible citrus germplasm following infection with these two pathogens but not in trifoliate orange.These findings provide a comprehensive understanding of citrus root rot and support future research on the mechanisms of root rot resistance in citrus.
基金supported by the Key Research and Development Program of Shandong Province,China(No 2021CXGC010803)Pan’an County Chinese Medicine Industry Project(No.PZYF202103).
文摘Reductive soil disinfestation(RSD)is commonly employed for soil remediation in greenhouse cultivation.However,its influence on antibiotic resistance genes(ARGs)in soil remains uncertain.This study investigated the dynamic changes in soil communities,potential bacterial pathogens,and ARG profiles under various organicmaterial treatments during RSD,including distillers’grains,potato peel,peanut vine,and peanut vine combined with charcoal.Results revealed that applying diverse organic materials in RSD significantly altered bacterial community composition and diminished the relative abundance of potential bacterial pathogens(P<0.05).The relative abundance of high-risk ARGs decreased by 10.7%-30.6%after RSD treatments,the main decreased ARG subtypeswere AAC(3)_Via,dfrA1,ErmB,lnuB,aadA.Actinobacteria was the primary host of ARGs and was suppressed by RSD.Soil physicochemical properties,such as total nitrogen,soil pH,total carbon,were crucial factors affecting ARG profiles.Our findings demonstrated that RSD treatment inhibited pathogenic bacteria and could be an option for reducing high-risk ARG proliferation in soil.
基金supported by the National Modern Agricultural Industry Technology System(CARS-45-33)Innovation Team of Tianjin Freshwater Aquaculture Industry Technology System(ITTFRS2021000-002,ITTFRS2021000-001)+1 种基金Tianjin Science and Technology Plan Project(24KPHDRC00280,24ZYCGSN00250,23YDTPJC00420)the Open Fund Project of Key Laboratory of Ocean Observation Technology,MNR(No.2023klootA03).
文摘The sustainable development of aquaculture industry is deeply constrained by pathogens and diseases,and traditional detection methods are difficult to adapt to the needs of intensive aquaculture due to low efficiency and insufficient sensitivity.This article reviews the progress of rapid detection technology for aquatic pathogens based on molecular biology,immunology,biosensors,etc.,and analyzes the application value of innovative methods such as isothermal amplification and CRISPR.This technology injects core momentum into the new quality productivity of fisheries through early and precise identification of pathogens:reducing aquaculture losses to improve resource efficiency,promoting the transformation of aquaculture models to data-driven,ensuring the safety of aquatic products to enhance the competitiveness of the industry chain.The current technology has shortcomings such as lagging standardization,weak on-site anti-interference ability,and insufficient recognition of new pathogens.In the future,we need to focus on technological integration and innovation,intelligent upgrading,and standardization construction,promote technology from laboratories to industrial applications,and provide continuous support for the high-quality development of fisheries.
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.
文摘Detection and monitoring of pathogens is a central aspect of maintaining public health.Rare and neglected zoonotic viruses have the potential to evolve and expand exponentially,leading to unforeseen outbreaks,epidemics,and pandemics.The emerging multiomics and meta-omics techniques and workflows,such as proteogenomics and meta-genomics,offer the potential for the detection of harmful pathogens,as well as opportunities for the discovery of previously unknown bacterial,parasitic,or viral pathogens.Multiomics and meta-omics workflows provide molecular information for tracking pathogens and understanding the effectiveness of spread mitigation strategies.In addition to environmental monitoring,multiomics and meta-omics approaches have the potential for clinical applications and in-depth characterization of novel pathogens.In this review,we discuss recent applications of multiomics and meta-omics techniques,their advantages over traditional methods,and their potential implementations in biomedical research,environmental studies,and healthcare.We critically assess the benefits and challenges of multiomics and meta-omics studies and discuss their future perspectives.
基金supported by the Beijing Science and Technology Planning Project of the Beijing Science and Technology Commission(Z241100009024047)the High-Level Public Health Technical Talent Training Plan(lingjunrencai-01-02).
文摘Respiratory infections are associated with high morbidity and mortality and are a major global health problem[1].Acute respiratory infections are caused by multiple respiratory pathogens,including viruses and bacteria.Viral-bacterial co-infections,which have become increasingly common and a global concern,can lead to substantial complications,causing higher morbidity and adverse prognosis[2].Previous studies have reported low positive detection rates of targeted pathogens related to acute respiratory infections,owing to the limited number of detected pathogens and variations in the sensitivity of diagnostic methods[3-4].Low positive detection rates may impede our understanding of respiratory pathogen characteristics and hamper the development of precise treatment and prevention strategies.
基金supported by grants from the National Key Research and Development Program of China(Nos.2023YFA0915200,2023YFA0915204)the Equipment Research and Development Projects of the Chinese Academy of Sciences(No.PTYQ2024YZ0010)+3 种基金the Science and Technology Commission of Shanghai Municipality Project(No.XTCX-KJ-2024-038)the Natural Science Foundation of Hebei Province of China(No.H2024206249)the Postdoctoral Fellowship Program of CPSF(No.GZC20232838)Science and Technology Commission of Shanghai Municipality(No.22S31901700).
文摘The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a molding process,which enables the batch detection of pathogens.It explores the rapid lysis and elution processes of pathogens within the microfluidic chips to ensure that nucleic acid extraction,elution,and amplification are completed entirely within the chip.This chip can extract nucleic acids from samples in just 10 min,achieving an extraction efficiency comparable to that of traditional in-tube methods.An oil phase is pre-loaded into the chip to effectively prevent aerosol contamination.This approach allows for the simultaneous detection of 21 common respiratory pathogens,with a detection limit of 10 copies per reaction.Furthermore,applications involving clinical samples demonstrate significant practicality.Compared to many traditional in-tube pathogen detection methods and molecular biology technologies that utilize microfluidic chips,this detection chip not only enables simultaneous detection of multiple pathogens but also demonstrates high sensitivity.
基金supported by the National Natural Science Foundation of China(32272557 and 32072500)the Major Basic Research Project of the Natural Science Foundation of Shandong Province(ZR2022ZD23 and ZR2024ZD07)+4 种基金the Shandong Province Key Research and Development Plan(2024CXGC010908 and 2024LZGCQY009)the Taishan Scholar Program of Shandong Province(tstp20221117)the Zaozhuang Major Scientific and Technological Innovation Project(2023GH12)the Science and Technology Innovation Guidance Project of the Ningxia Academy of Agriculture and Forestry Sciences(NKYG-25-21)the"First Class Discipline"Construction Project of Shandong Agricultural University(811).
文摘The apoplast is a critical interface where plants and pathogens engage in biochemical confrontation.Within this shared extracellular space,plant defense responses provoke countermeasures from pathogens.We introduce apoplastic interactive balance(AIB),a framework depicting the dynamic equilibrium that emerges from these interactions.AIB emphasizes that system-level functional stability arises from both balanced and divergent molecular strategies,with transient imbalances driving coevolutionary refinement.These interactions are classified into four modules:metabolites,proteins,small peptides,and extracellular vesicles(EVs).Across these modules,plants and pathogens deploy parallel molecular tactics shaped by adaptive coevolution.This conceptual view provides a foundation for hypothesis generation,comparative analysis among species,and the design of rational immune strategies.
基金supported by grants from the National Natural Science Foundation of China(32172890 and 32002315)the National Key Research and Development Program of China(2022YFF0711004)+3 种基金the Natural Science Foundation of Heilongjiang Province,China(YQ2022C042)the State Key Laboratory of Veterinary Biotechnology Foundation of China(SKLVBF202208)the Postdoctoral Fellowship Program of CPSF,China(GZC20233062)the National Center of Technology Innovation for Pigs,China(NCTIP-XD/C09)。
文摘NADC34-like porcine reproductive and respiratory syndrome virus(PRRSV),which first appeared in China in 2017,is currently one of the main epidemic strains in China.In this study,we found that a new variant of NADC34-like PRRSV evolved,named the L1A variant.The phylogenetics,epidemic status,and pathogenicity of the LA variants were subsequently comprehensively evaluated.Based on the results of the ORF5 phylogenetic analysis,the L1A variants were classified as NADC34-like PPRSV.All the strains had the same discontinuous 131-aa deletion in the NSP2 region(similar to that in the NADC30).Recombination analysis revealed that the L1A variants were recombinant viruses that contained an NADC30-like PRRSV skeleton,a nonstructural protein-encoding gene region obtained in part from JXA1-like PRRSV and a ORF2-ORF6 gene region partly obtained from NADC34-like PRRSV and that exhibited similar recombination patterns.We successfully isolated the L1A variant TZJ2756 from PAMs and Marc-145 cells.In animal experiments,TZJ2756 exhibited moderate pathogenicity in piglets,causing obvious clinical symptoms,namely,persistent fever,significantly reduced body weight,interstitial edema and severe interstitial pneumonia in the lungs,and prolonged high-load viremia.L1A variants have been detected in at least 12 provinces in China and share many similar epidemiological characteristics with the American L1C variant.This research will enhance our understanding of the prevalence of L1A variants and furnish valuable data for the ongoing monitoring of NADC34-like PRRSV in China.
基金supported by the Ministry of Science and Technology of the People’s Republic of China(2022YFD1800400).
文摘Staphylococcus aureus(S.aureus)is the third most common pathogen causing 10.6%of bacterial foodborne illnesses in China in 2021[1].Heat-stable Staphylococcal Enterotoxins(SEs)produced by S.aureus are the main contributors to staphylococcal food poisoning(SFP),causing vomiting,diarrhea,abdominal pain,headache,muscle cramps,and other acute gastroenteritis symptoms.More than 25 SEs and staphylococcal enterotoxin-like toxins(SE/s)have been described and which together comprise a superfamily of pyrogenic toxin superantigens(SAgs)[2].
基金supported by the National Natural Science Foundational of China,Nos.U24A20692(to CJZ),82371355(to CJZ),and 82101414(to MH)National NaturalScience Foundational of China for Excellent Young Scholars,No.82022019(to CJZ)+5 种基金Sichuan Special Fund for Distinguished Young Scholars,No.24NSFJQ0052(to CJZ)The Innovationand Entrepreneurial Team of Sichuan Tianfu Emei Program,No.CZ2024018(to CJZ)Funding for Distinguished Young Scholars of Sichuan Provincial People’sHospital,No.30420230005Funding for Distinguished Young Scholars of University of Electronic Science and Technology of China,No.A1098531023601381(toCJZ)Sichuan Science and Technology Support Project,No.2023YFS0212(to BH)Project of Sichuan Provincial Health Commission,No.19PJ265(to LD).
文摘Multiple sclerosis is a severe autoimmune disorder that is mainly mediated by pathogenic cluster of CD4^(+)T cell subsets.Despite advancements in the management of multiple sclerosis,there is a critical need for more effective and safer treatments.In the present study,we administered Lycium barbarum glycopeptide to a mouse model of experimental autoimmune encephalomyelitis-an animal model of multiple sclerosis-and evaluated its effects on pathogenic CD4^(+)T cell activation both in vivo and in vitro.Lycium barbarum glycopeptide significantly mitigated the clinical severity of experimental autoimmune encephalomyelitis,as demonstrated by reduced demyelination and neuroinflammation.Moreover,Lycium barbarum glycopeptide treatment decreased the infiltration of peripheral leukocytes into the central nervous system and suppressed pro-inflammatory cytokine expression.Lycium barbarum glycopeptide also modulated pathogenic CD4^(+)T cell activation by inhibiting T helper 1/T helper 17 cell differentiation while promoting regulatory T cell expansion.Notably,no side effects were observed,suggesting the long-term safety and tolerability of Lycium barbarum glycopeptide.Furthermore,RNA sequencing data indicated that Lycium barbarum glycopeptide inhibits activator protein-1,an essential regulator of T cell activation and differentiation.This finding was supported by the reversal of T helper/T helper 17 cell response suppression upon AP-1 blockade.Collectively,these results highlight the potential of Lycium barbarum glycopeptide as an innovative therapeutic agent for CD4^(+)T cell-associated autoimmune or inflammatory diseases,such as multiple sclerosis.
基金Major National Science and Technology Projects(Grant No.2013ZX10004605,2013ZX10004605001004)
文摘The pathogens and opinion for antibiotic treatment in adult patients with 1-14 fecal white blood cells per high power field （WBC/HPF） of acute non-bloody diarrhea remain obscure. The study attempts to clarify it. Stool specimens of adult patients with acute non-bloody diarrhea and stool examination showing 1-14 fecal WBC/HPF were collected for bacterial culture and viral detection. Patients included in this study were 196 cases with mean age of （37.9±17.4） years and 42.3% was women. The bacterial and viral detection rates were 63 （32.1%） and 21 （10.7%）, respectively. Of the isolated pathogens, campylobacteria was present in 14 （22.0%） samples and was the most common bacteria and calicivirus was found in 10 （47.6%） samples and was the most common virus. Based on single pathogens, 46 cases were caused by invasive pathogens, 26 cases were caused by non-invasive pathogens. The body temperature was significantly higher in feverish patients caused by invasive pathogens than those caused by non-invasive pathogens （（38.44-0.7） ℃ vs （37.74-0.4） ℃, P = 0.002）. The probability of diarrhea caused by invasive pathogens was higher in patients with T〉38.4℃ than those with T_〈38.4℃ （RR = 1.5）. When T〉38.4℃ is used as the threshold for antibiotic treatment, the misuse rate of antibiotics would decrease from 26.9% to 3.8% （P = 0.021）. So T〉38.4 ℃ may be used as a possible reference value for antibiotic treatment in adult patients with 1-14 fecal WBC/HPF of acute non-bloody diarrhea.
基金Supported by Science and Technology Plan Project of Fujian Province(2013Y0063)Xiamen South Ocean Research Centre Project(13GZP002NF08)~~
文摘[Objective] The aim of this study was to purify an antimicrobial protein from a biocontrol bacterium strain K2-1 and analyze its antimicrobial activity in vitro against some typical aquatic pathogens. [Method] The antimicrobial protein was ob- tained by using ammonium sulfate precipitation and Sephadex chromatography combined with hot water bath. The antimicrobial assay was conducted by means of agar diffusion technique, using Vibrio alginolyticus, Aeromonas hydrophila, Aeromonas. Sobria, Pseudomonas fluorescens, Vibrio Parahaemolyticus, Vibrio har- veyi and Vibrio anguillarum as test bacteria. [Result] Antimicrobial protein APK2 can be derived from fermentation broth of strain K2-1 and purified to the chromatogra- phy pure level by the methods provided, the final yield of the antimicrobial compo- nent is approximately 0.08%. This antimicrobial protein had a strong antimicrobial activity against the growth of most those bacteria. [Conclusion] The results show that APK2 could be a potential alternative to replace chemical antimicrobial agent in the control and prevention of aquatic diseases.
基金supported by the National Natural Science Foundation of China(No.51290281)the project of Chinese Academy of Sciences(No.QYZDY-SSW-DQC004)the Federal Department of Chinese Water Control and Treatment(Nos.2017ZX07108,2017ZX07501002)
文摘The effects of O3/Cl2 disinfection on corrosion and the growth of opportunistic pathogens in drinking water distribution systems were studied using annular reactors （ARs）. The corrosion process and most probable number （MPN） analysis indicated that the higher content of iron-oxidizing bacteria and iron-reducing bacteria in biofilms of the AR treated with O3/Cl2 induced higher Fe304 formation in corrosion scales. These corrosion scales became more stable than the ones that formed in the AR treated with Cl2 alone. O3/Cl2 disinfection inhibited corrosion and iron release efficiently by changing the content of corrosion-related bacteria. Moreover, ozone disinfection inactivated or damaged the opportunistic pathogens due to its strong oxidizing properties. The damaged bacteria resulting from initial ozone treatment were inactivated by the subsequent chlorine disinfection. Compared with the AR treated with Cl2 alone, the opportunistic pathogens M. auium and L. pneumophila were not detectable in effluents of the AR treated with O3/Cl2, and decreased to （4.60 ± 0.14） and （3.09 ± 0.12） loglo （gene copies/g corrosion scales） in biofilms, respectively. The amoeba counts were also lower in the AR treated with O3/Cl2. Therefore, O3/Cl2 disinfection can effectively control opportunistic pathogens in effluents and biofilms of an AR used as a model for a drinking water distribution system.
基金supported in part by the Universidad de los Andes Faculty of Sciencesby basic sciences project P13.700022.007 from the University of los Andes Office of Research+1 种基金by COLCIENCIAS grant # 120-4521-28532Colciencias (Programa de Apoyo a Doctorados Nacionales) for the financial support of the Ph.D. studies of M.F.G. and H.Y.N.-O
文摘The importance of pyrimidines lies in the fact that they are structural components of a broad spectrum of key molecules that participate in diverse cellular functions, such as synthesis of DNA, RNA, lipids, and carbohydrates. Pyrimidine metabolism encompasses all enzymes involved in the synthesis, degradation, salvage, interconversion and transport of these molecules. In this review, we summarize recent publications that document how pyrimidine metabolism changes under a variety of conditions, including, when possible, those studies based on techniques of genomics, transcriptomics, proteomics, and metabolomics. First, we briefly look at the dynamics of pyrimidine metabolism during nonpathogenic cellular events. We then focus on changes that pathogen infections cause in the pyrimidine metabolism of their host. Next, we discuss the effects of antimetabolites and inhibitors, and finally we consider the consequences of genetic ma- nipulations, such as knock-downs, knock-outs, and knock-ins, of pyrimidine enzymes on pyrimidine metabolism in the cell.
基金supported by the National Natural Science Foundation of China(No.51138006)the National Key Research on Water Environment Pollution Control in China(No.2012ZX07301-001)
文摘The emergence and prevalence of antibiotic resistance genes(ARGs) and pathogens in the environment are serious global health concern. However, information about the occurrence of ARGs and pathogens in recreational water is still limited. Accordingly, we investigated the occurrence of six ARGs and human pathogens in three recreational lakes, and the correlations between ARGs and one mobile genetic element(intI1) were analyzed. The quantitative PCR results showed that the concentration of ARGs ranged from 4.58 × 10~0 to 5.0 × 10~5 copies/mL in water and from 5.78 × 10~3 to 5.89 × 10~8 copies/g dry weight(dw)in sediment. Sul1 exhibited the highest level among the five quantifiable ARGs. The concentrations of sul1, bla_(-TEM), and tetX exhibited significant positive correlations with intI1(p < 0.05), indicating that intI1 may be involved in their proliferation. The detection frequencies of ARGs ranged from 75%–10~0%, indicating the prevalence of these risks in this region. The concentration of Escherichia coli, Aeromonas spp., Mycobacterium avium,Pseudomonas aeruginosa, and Salmonella enterica ranged from 10~3 to 10~5 copies/10~0 mL in water and 10~4–10~6 copies/g dw in sediment. In total, 25% of the samples harbored all pathogen genes, indicating the prevalence of these pathogens in recreational lakes.Furthermore, the next-generation sequencing results showed that 68 genera of pathogens were present, among which Aeromonas, Mycobacterium, and Pseudomonas were the dominant ones in this region, posing a considerable potential health risk to public health. Overall, the widespread distribution of ARGs and pathogens underscores the need to better monitor and mitigate their propagation in recreational lakes and the associated risks to human health.
基金supported by the National Basic Research Development Program of China(Grant No. 2009CB118401)the National High-tech Research and Development Program of China(Grant Nos.2012AA10A305 and 2012AA 101104)
文摘Plant pathogens have evolved numerous strategies to obtain nutritive materials from their host, and plants in turn have evolved the preformed physical and chemical barriers as well as sophisticated two-tiered immune system to combat pathogen attacks. Genetically, plant resistance to pathogens can be divided into qualitative and quantitative disease resistance, conditioned by major gene（s） and multiple genes with minor effects, respectively. Qualitative disease resistance has been mostly detected in plant defense against biotrophic pathogens, whereas quantitative disease resistance is involved in defense response to all plant pathogens, from biotrophs, hemibiotrophs to necrotrophs. Plant resistance is achieved through interception of pathogen-derived effectors and elicitation of defense response. In recent years, great progress has been made related to the molecular basis underlying host--pathogen interactions. In this review, we would like to provide an update on genetic and molecular aspects of plant resistance to pathogens.
基金the California Department of Food and Agriculture Fruit Tree, Nut Tree, and Grapevine Improvement Advisory Board, USA
文摘Due to increasing regulations and restrictions, there is an urgent need to develop effective alternatives to chemical-dependent fumigation control of soilborne pests and pathogens. Anaerobic soil disinfestation （ASD） is one such alternative showing great promise for use in the control of soilborne pathogens and pests. This method involves the application of a carbon source, irrigation to field capacity, and covering the soil with a plastic tarp. While the mechanisms of ASD are not completely understood, they appear to be a combination of changes in the soil microbial community composition, production of volatile organic compounds, and the generation of lethal anaerobic conditions. The variety of materials and options for ASD application, including carbon sources, soil temperature, and plastic tarp type, influence the efficacy of pathogen sup- pression and disease control. Currently, both dry （e.g., rice bran） and liquid （e.g., ethanol） carbon sources are commonly used, but with different results depending on environmental conditions. While solarization is not an essential component of ASD, it can enhance efficacy. Understanding the mechanisms that mediate biological changes occurring in the soil during ASD will facilitate our ability to increase ASD efficacy while enhancing its commercial viability.
文摘Spontaneous bacterial peritonitis(SBP) is the most typical infection observed in cirrhosis patients. SBP is responsible for an in-hospital mortality rate of approximately 32%. Recently, pattern changes in the bacterial flora of cirrhosis patients have been observed, and an increase in the prevalence of infections caused by multi-resistant bacteria has been noted. The wide-scale use of quinolones in the prophylaxis of SBP has promoted flora modifications and resulted in the development of bacterial resistance. The efficacy of traditionally recommended therapy has been low in nosocomial infections(up to 40%), and multi-resistance has been observed in up to 22% of isolated germs in nosocomial SBP. For this reason, the use of a broad empirical spectrum antibiotic has been suggested in these situations. The distinction between community-acquired infectious episodes, healthcare-associated infections, or nosocomial infections, and the identification of risk factors for multi-resistant germs can aid in the decision-making process regarding the empirical choice of antibiotic therapy. Broad-spectrum antimicrobial agents, such as carbapenems with or without glycopeptides or piperacillin-tazobactam, should be considered for the initial treatment not only of nosocomial infections but also of healthcare-associated infections when the risk factors or severity signs for multi-resistant bacteria are apparent. The use of cephalosporins should be restricted to community-acquired infections.
基金project was approved by the research committee of Faculty of Medical Laboratory Sciences,University of Khartoum as Ph D degree requirements to Aymen Nurain
文摘Objective:To determine the prevalence and antimicrobial resistance rates of nosocomial pathogens isolated from cancer patients and hospital environments.Methods:A descriptive cross-sectional study was conducted between December 2010 to May 2013 at Radiation and Isotopes Centre of Khartoum,Sudan.A total of 1 503 samples(505 clinical and 998 environmental)were examined.Isolates were identified,and their antimicrobial susceptibility was determined using standard laboratory procedures.Results:Out of 505 clinical samples,nosocomial pathogens were found as 48.1%.Among hospital environment samples,bacterial contaminants were detected in 29.7%of samples.The main microorganisms recovered from cancer patients were Proteus spp.(23.5%),Escherichia coli(22.2%),Pseudomonas aeruginosa(P.aeruginosa)(21.0%)and Staphylococcus aureus(20.2%).The most frequent isolates from hospital environments were Bacillus spp.(50.0%),Staphylococcus aureus(14.2%)and P.aeruginosa(11.5%).The proportions of resistance among Gram-negative pathogens from cancer patients were high for ampicillin,cefotaxime,ceftazidime and ceftriaxone.Moderate resistance rates were recorded to ciprofloxacin,such as 51.0%for P.aeruginosa,21.7%for Klebsiella pneumoniae and 55.5%for Escherichia coli.Except Klebsiella,there were no significant differences(P0.05)of resistance rates between Gram-negative isolates from cancer patients to those from the hospital environments.The proportions of extended-spectrum b-lactamase producing isolates from cancer patients were not differ significantly(P=0.763)from those collected from the hospital environments(49.2%;91/185 vs.47%;32/68).Conclusions:The prevalence of nosocomial infection among cancer patients was high(48.1%)with the increasing of antimicrobial resistance rates.Hospital environments are potential reservoirs for nosocomial infections,which calls for intervention program to reduce environmental transmission of pathogens.
