Objective:To analyse the prevalence of serotypes,antibiotic resistance,and virulence genes of Group B Streptococcus(GBS)strains isolated from pregnant women at 35-37 weeks of gestation in Ho Chi Minh City,Vietnam,from...Objective:To analyse the prevalence of serotypes,antibiotic resistance,and virulence genes of Group B Streptococcus(GBS)strains isolated from pregnant women at 35-37 weeks of gestation in Ho Chi Minh City,Vietnam,from January 2022 to January 2023.Methods:GBS strains were isolated through selective culture methods and confirmed by PCR.Serotyping,virulence gene detection,and antibiotic susceptibility testing were performed using PCR,gel electrophoresis techniques and Kirby-Bauer test.Results:Totally,61 GBS isolated from 300 participants have been identified including seven GBS serotypes(Ⅰa,Ⅰb,Ⅱ,Ⅲ,Ⅳ,Ⅴ,andⅥ).SerotypesⅦ,Ⅷ,andⅨwere not detected in the study population.Antibiotic resistance patterns varied:13.1%of isolates were fully susceptible,while the majority showed multi-drug resistance,with 34.4%resistant to three antibiotics.SerotypeⅠa demonstrated high susceptibility(35.7%),while serotypeⅢshowed extensive resistance,with 87.5%being resistant to at least three antibiotics.All strains are susceptible to vancomycin andβ-lactams susceptibility also remained high,but resistance to clindamycin,erythromycin,and tetracycline was high(>65%).The virulence genes scpB,cylB,fbsB,and cfb were highly prevalent(90%-100%),indicating their potential for vaccine and diagnostic development.Conclusions:Our findings provide valuable insights into GBS serotypes,resistance,and virulence factors,contributing to community monitoring,preventive measures,diagnostics,and vaccine development.However,the limited sample size necessitates further research.展开更多
Bacterial infections of avian embryos can lead to an increase in embryo mortality,and the proliferation of antimicrobial-resistant bacteria aggravates the situation.A low hatching rate also poses a challenge to the po...Bacterial infections of avian embryos can lead to an increase in embryo mortality,and the proliferation of antimicrobial-resistant bacteria aggravates the situation.A low hatching rate also poses a challenge to the population of artificially bred Crested Ibises(Nipponia nippon).This study aims to determine the potential association between bacterial infection and the death of Crested Ibis embryos,and whether there is convergence between antimicrobial resistance and virulence in strain.In this study,13 Escherichia coli and 12 Proteus mirabilis isolates were recovered from dead Crested Ibis embryos.The pathogenicity examination confirmed the pathogenicity of all isolates,and multiple virulence genes detected by PCR-sequencing demonstrated the presence of irp2 and iuc D(100%),fim C and iss(92.31%)in E.coli,and uca A(58.33%)in P.mirabilis.Antimicrobial susceptibility test demonstrated that isolates were mainly resistant to amoxicillin(E.coli:76.92%,P.mirabilis:91.67%),cefazolin(E.coli:76.92%,P.mirabilis:91.67%),oxytetracycline(E.coli:92.31%,P.mirabilis:75.00%)and sulfamethoxazole-trimethoprim(E.coli:53.85%,P.mirabilis:33.33%),and more than 30%of isolates showed multidrug-resistance(MDR).Further analyses detected extended-spectrumβ-lactamase(ESBL)genes,of which blaTEM-1(E.coli:100%,P.mirabilis:100%)had the highest frequency,followed by the blaCTX-M-55(E.coli:92.31%,P.mirabilis:50%),blaCTX-M-14(E.coli:76.92%,P.mirabilis:33.33%),blaCTX-M-65(E.coli:15.38%,P.mirabilis:16.67%),and all isolates were negative for blaSHV and blaOXA.Pearson's correlation analysis showed a positive correlation between the presence ofβ-lactam resistance and ESBL genes,while mainly negative correlations were observed between the presence of ESBL genes and virulence genes.Furthermore,the conjugation experiment and PFGE revealed that the isolates were primarily polyclonal,and there was horizontal transfer of resistance or virulence genes by plasmids.Based on the results,E.coli and P.mirabilis were responsible for embryonic mortality of the ibises in this study.The co-presence and co-transfer of ESBL genes and virulence genes can pose a potential threat to the health of the Crested Ibis,and measures such as prudent use of antimicrobials,and constant surveillance of resistance and pathogenicity,must be implemented at the Crested Ibis breeding base.展开更多
Objective Pseudomonas aeruginosa(P.aeruginosa)is a prevalent pathogenic bacterium involved in meningitis;however,the virulence factors contributing to this disease remain poorly understood.Methods The virulence of the...Objective Pseudomonas aeruginosa(P.aeruginosa)is a prevalent pathogenic bacterium involved in meningitis;however,the virulence factors contributing to this disease remain poorly understood.Methods The virulence of the P.aeruginosa A584,isolated from meningitis samples,was evaluated by constructing in vitro blood-brain barrier and in vivo systemic infection models.qPCR,whole-genome sequencing,and drug efflux assays of A584 were performed to analyze the virulence factors.Results Genomic sequencing showed that A584 formed a phylogenetic cluster with the reference strains NY7610,DDRC3,Pa58,and Pa124.Its genome includes abundant virulence factors,such as hemolysin,the Type IV secretion system,and pyoverdine.A584 is a multidrug-resistant strain,and its wide-spectrum resistance is associated with enhanced drug efflux.Moreover,this strain caused significantly more severe damage to the blood-brain barrier than the standard strain,PAO1.qPCR assays further revealed the downregulation of the blood-brain barrier-associated proteins Claudin-5 and Occludin by A584.During systemic infection,A584 exhibited a higher capacity of brain colonization than PAO1(37.1×10^(6) CFU/g brain versus 2.5×10^(6) CFU/g brain),leading to higher levels of the proinflammatory factors IL-1βand TNF-α.Conclusion This study sheds light on the virulence factors of P.aeruginosa involved in meningitis.展开更多
Helicobacter pylori infection represents a widespread chronic condition with varying prevalence influenced by race, ethnicity, and geography. The severity of H. pylori-associated diseases is determined by an array of ...Helicobacter pylori infection represents a widespread chronic condition with varying prevalence influenced by race, ethnicity, and geography. The severity of H. pylori-associated diseases is determined by an array of virulence factors. Although extensive studies have been conducted globally, data on the distribution of Helicobacter pylori virulence genes in Libya remain limited, constraining insights into the pathogenicity of local strains and hindering the development of targeted interventions. This study aimed to evaluate the prevalence of H. pylori infection, characterize essential virulence genes [vacA variants (s1/s2, m1/m2), cagA, and iceA1], and examine their association with gastroduodenal diseases among Libyan patients. Gastric biopsies from 144 participants were analyzed using polymerase chain reaction (PCR) assays, and risk factor data were collected via questionnaires. H. pylori was detected in 63.2% of samples by PCR. The vacA gene was present in 84.6% of cases, cagA in 58.2%, and iceA1 in 29.7%. Among vacA variants, s1 allele was most common (53.2%), followed by m1 (42.9%), m2 (37.7%), and s2 (13%) alleles. Significant associations were identified between specific virulence genes and the development of gastroduodenal diseases, highlighting their role in pathogenicity. This investigation is one of Libya’s first comprehensive assessments of H. pylori virulence factors, addressing a critical epidemiological gap. The high prevalence of virulence genes suggests their potential as disease biomarkers. These findings contribute to a deeper understanding of H. pylori pathogenicity within the Libyan population and establish a basis for future clinical interventions and public health strategies to manage and prevent H. pylori-associated diseases in Libya and comparable regions.展开更多
Aeromonas veronii is considered an emerging food-borne pathogen associated with a significant threat to public health,distributed in various aquatic environments and products.Hanks-type serine/threonine kinases(STKs)p...Aeromonas veronii is considered an emerging food-borne pathogen associated with a significant threat to public health,distributed in various aquatic environments and products.Hanks-type serine/threonine kinases(STKs)play a critical role in the pathogenesis of pathogens.However,the function of A.veronii STKs is currently unclear.By constructing a markerless prk A in-frame deletion strain,Δprk A,we found that i)the colonies of theΔprk A strain were larger after 1 h of high temperature at 50℃compared with the wild-type strain TH0426 and the complementary strain C-prk A,and the number of viable bacteria of theΔprk A strain increased significantly;ii)theΔprk A strain significantly enhanced the adhesion ability to epithelioma papulosum cyprini(EPC)cells;iii)theΔprk A strain was significantly more virulent than the TH0426 strain,at both the cellular and animal levels;and iv)RNA-seq results showed a total of 984 differentially expressed genes(DEGs)between theΔprk A strain and the TH0426 strain,which were enriched in 70 Kyoto Encyclopedia of Genes and Genomes(KEGG)metabolic pathways,mainly involved in bacterial ribosomes,flagellar assembly,type Ⅱ secretion system(T2SS),and lipopolysaccharide metabolic pathways.Taken together,the findings of this study indicate that the Hanks-type STK Prk A negatively regulates several biological processes,such as the temperature tolerance and virulence of A.veronii.The results of this study provide an important reference for further elucidation of the pathogenesis of A.veronii.展开更多
The velvet protein family serves as a crucial factor in coordinating development and secondary metabolism in numerous pathogenic fungi.However,no previous research has examined the function of the velvet protein famil...The velvet protein family serves as a crucial factor in coordinating development and secondary metabolism in numerous pathogenic fungi.However,no previous research has examined the function of the velvet protein family in Fusarium oxysporum f.sp.niveum(FON),a pathogen causing a highly destructive disease in watermelon.In this study,∆fovel1 and∆folae1 deletion mutants and∆fovel1-C and∆folae1-C corresponding complementation mutants of FON were validated.Additionally,the phenotypic,biochemical,and virulence effects of the deletion mutants were investigated.Compared to the wild-type strains,the∆fovel1 and∆folae1 mutants exhibited altered mycelial phenotype,reduced conidiation,and decreased production of bikaverin and fusaric acid.Furthermore,their virulence on watermelon plant roots significantly decreased.All these alterations in mutants were restored in corresponding complementation strains.Notably,yeast two-hybrid results demonstrated an interaction between FoVel1 and FoLae1.This study reveals that FoVEL1 and FoLAE1 play essential roles in secondary metabolism,conidiation,and virulence in FON.These findings enhance our understanding of the genetic and functional roles of VEL1 and LAE1 in pathogenic fungi.展开更多
[Objective] This study aimed to explore the presence of three causative genes Colv,Stxs and HlyE of the pathogenic E.coli from chickens,pigs and food.[Method] By using 44 E.coli strains from chickens,24 from pigs and ...[Objective] This study aimed to explore the presence of three causative genes Colv,Stxs and HlyE of the pathogenic E.coli from chickens,pigs and food.[Method] By using 44 E.coli strains from chickens,24 from pigs and 26 from food as the experimental materials,virulence genes Colv,Stxs（stx2,stx2e） and HlyE were detected with polymerase chain reaction（PCR） method.[Result] Among all the E.coli strains,the detection rate of Colv was 25% from chickens,4.2% from pigs,and 0 from food;the detection rate of Stx2（Stx2e） from all E.coli strains was 0;the detection rate of HlyE was 2.27% from chickens,0 from pigs,and 11.5% from food.[Conclusion] Virulence gene Colv shows relatively high carrying rate in E.coli from chickens and pigs;HlyE also shows a certain degree of presence in E.coli from chickens and food.展开更多
Fungal pathogen of asparagus stem blight was isolated. No significant genetic difference was detected among the three strains with 492 bp long ITS1-5.8S-ITS2 sequence. It was then identified through colony growth, con...Fungal pathogen of asparagus stem blight was isolated. No significant genetic difference was detected among the three strains with 492 bp long ITS1-5.8S-ITS2 sequence. It was then identified through colony growth, conidia morphology, and molecular characterization. The physiological response to oxidation and osmosis stress, and virulence to Asparagus officinalis L. were analyzed. The results showed that the pathogen causing asparagus stem blight for A. officinalis L. in Jiangxi Province is Phomopsis asparagri (Sacc.) Bubák. Under pure culture conditions, the conidia were oval-shaped (α-type), with colorless single spore and single nucleus, containing 0-2 oil balls. Its vegetative growth rate was higher when cultured on 0.2 × potato dextrose agar (0.2 × PDA) medium than that on oatmeal agar (OA) medium. However, the pycnidia appeared earlier on OA medium than on 0.2 earlier PDA medium. The vegetative growth rate was depressed under oxidation (H2O2) or osmosis (NaCl) stress conditions, and totally inhibited under 7 mmol/L H2O2 or 2.4 mol/L NaCl. All the strains caused typical pathogenic symptoms to Asparagus officinalis L. at 7 days-post-inoculation (dpi) with conidia.展开更多
[ Objective] The paper was to screen Bacillus with strong antagonistic effect. [ Method] The diseased ginger and the surrounding soils were collected from Laiwu of Shandong Province, and the high-virulence strains of ...[ Objective] The paper was to screen Bacillus with strong antagonistic effect. [ Method] The diseased ginger and the surrounding soils were collected from Laiwu of Shandong Province, and the high-virulence strains of the pathogen of ginger blast （Ralstonia solanacearum） were isolated, Bacillus was used to carry out antagonistic test. [Result] Three strains LW-4, LW-7 and LW-32 had strong antagonistic effect against R. solanacearum, the area of their inhibition zone was larger than other strains. [ Conclusion] The study provided theoretical basis for the control of ginger blast.展开更多
Helicobacter pylori(H.pylori)is one of the most important human pathogens,infecting approximately half of the global population.Despite its high prevalence,only a subset of H.pylori infected individuals develop seriou...Helicobacter pylori(H.pylori)is one of the most important human pathogens,infecting approximately half of the global population.Despite its high prevalence,only a subset of H.pylori infected individuals develop serious gastroduodenal pathology.The pathogenesis of H.pylori infection and disease outcome is thus thought to be mediated by an intricate interplay between host,environmental and bacterial virulence factors.H.pylori has adapted to the harsh milieu of the human stomach through possession of various virulence genes that enable survival of the bacteria in the acidic environment,movement towards the gastric epithelium,and attachment to gastric epithelial cells.These virulence factors enable successful colonization of the gastric mucosa and sustain persistent H.pylori infection,causing chronic inflammation and tissue damage,which may eventually lead to the development of peptic ulcers and gastric cancer.Numerous studies have focused on the prevalence and role of putative H.pylori virulence genes in disease pathogenesis.While several virulence factors with various functions have been identified,disease associations appear to be less evident,especially among different study populations.This review presents key findings on the most important H.pylori virulence genes,including several bacterial adhesins and toxins,in children and adults,and focuses on their prevalence,clinical significance and potential relationships.展开更多
Helicobacter pylori(H. pylori) is a model organism for understanding host-pathogen interactions and infection-mediated carcinogenesis. Gastric cancer and H. pylori colonization indicates the strong correlation. The pr...Helicobacter pylori(H. pylori) is a model organism for understanding host-pathogen interactions and infection-mediated carcinogenesis. Gastric cancer and H. pylori colonization indicates the strong correlation. The progression and exacerbation of H. pylori infection are influenced by some factors of pathogen and host. Several virulence factors involved in the proper adherence and attenuation of immune defense to contribute the risk of emerging gastric cancer, therefore analysis of them is very important. H. pylori also modulates inflammatory and autophagy process to intensify its pathogenicity. From the host regard, different genetic factors particularly affect the development of gastric cancer. Indeed, epigenetic modifications, Micro RNA and long non-coding RNA received more attention. Generally, various factors related to pathogen and host that modulate gastric cancer development in response to H. pylori need more attention due to develop an efficacious therapeutic intervention. Therefore, this paper will present a brief overview of host-pathogen interaction especially emphases on bacterial virulence factors, interruption of host cellular signaling, the role of epigenetic modifications and non-coding RNAs.展开更多
AIM: To determine the features of Enterococcus that contribute to the development and maintenance of the inflammatory process in patients with inflammatory bowel disease (IBD). METHODS: Multiplex polymerase chain reac...AIM: To determine the features of Enterococcus that contribute to the development and maintenance of the inflammatory process in patients with inflammatory bowel disease (IBD). METHODS: Multiplex polymerase chain reaction (PCR) was applied to assess the presence of genes that encode virulence factors [surface aggregating protein (asa1), gelatinase (gelE), cytolysin (cylA), extracellular surface protein (esp) and hyaluronidase (hyl)] in the genomic DNA of 28 strains of Enterococcus isolated from the intestinal tissues of children with IBD (n =16) and of children without IBD (controls; n = 12). Additionally, strains with confirmed presence of the gelE gene were tested by PCR for the presence of quorum sensing genes (fsrA, fsrB, fsrC) that control the gelatinase production. Gelatinase activity was tested on agar plates containing 1.6% gelatin. We also analysed the ability of Enterococcus strains to release and decompose hydrogen peroxide (using Analytical Merckoquant peroxide test strips) and tested their ability to adhere to Caco-2 human gut epithelium cells and form biofilms in vitro. RESULTS: A comparison of the genomes of Enterococcus strains isolated from the inflamed mucosa of patients with IBD with those of the control group showed statistically significant differences in the frequency of theasa1 gene and thegelE gene. Furthermore, the cumulative occurrence of different virulence genes in the genome of a single strain ofEnterococcus isolated from the IBD patient group is greater than in a strain from the control group, although no significant difference was found. Statistically significant differences in the decomposition of hydrogen peroxide and adherence to the Caco-2 epithelial cell line between the strains from the patient group and control group were demonstrated. The results also showed that profuse biofilm production was more frequent amongEnterococcus strains isolated from children with IBD than in control strains. CONCLUSION: Enterococcus strains that adhere strongly to the intestinal epithelium, form biofilms and possess antioxidant defence mechanisms seem to have the greatest influence on the inflammatory process.展开更多
African swine fever virus(ASFV)is the etiological agent of African swine fever(ASF),an often lethal disease in domestic and wild pigs.ASF represents a major threat to the swine industry worldwide.Currently,no commerci...African swine fever virus(ASFV)is the etiological agent of African swine fever(ASF),an often lethal disease in domestic and wild pigs.ASF represents a major threat to the swine industry worldwide.Currently,no commercial vaccine is available because of the complexity of ASFV or biosecurity concerns.Live attenuated viruses that are naturally isolated or genetically manipulated have demonstrated reliable protection against homologous ASFV strain challenge.In the present study,a mutant ASFV strain with the deletion of ASFV MGF-110-9L(ASFV-D9L)was generated from a highly virulent ASFV CN/GS/2018 parental strain,a genotypeⅡASFV.Relative to the parental ASFV isolate,deletion of the MGF-110-9L gene significantly decreased the ability of ASFV-D9L to replicate in vitro in primary swine macrophage cell cultures.The majority of animals inoculated intramuscularly with a low dose of ASFV-D9L(10 HAD50)remained clinically normal during the 21-day observational period.Three of five ASFV-D9L-infected animals displayed low viremia titers and low virus shedding and developed a strong virus-specific antibody response,indicating partial attenuation of the ASFV-D9L strain in pigs.The findings imply the potential usefulness of the ASFV-D9L strain for further development of ASF control measures.展开更多
文摘Objective:To analyse the prevalence of serotypes,antibiotic resistance,and virulence genes of Group B Streptococcus(GBS)strains isolated from pregnant women at 35-37 weeks of gestation in Ho Chi Minh City,Vietnam,from January 2022 to January 2023.Methods:GBS strains were isolated through selective culture methods and confirmed by PCR.Serotyping,virulence gene detection,and antibiotic susceptibility testing were performed using PCR,gel electrophoresis techniques and Kirby-Bauer test.Results:Totally,61 GBS isolated from 300 participants have been identified including seven GBS serotypes(Ⅰa,Ⅰb,Ⅱ,Ⅲ,Ⅳ,Ⅴ,andⅥ).SerotypesⅦ,Ⅷ,andⅨwere not detected in the study population.Antibiotic resistance patterns varied:13.1%of isolates were fully susceptible,while the majority showed multi-drug resistance,with 34.4%resistant to three antibiotics.SerotypeⅠa demonstrated high susceptibility(35.7%),while serotypeⅢshowed extensive resistance,with 87.5%being resistant to at least three antibiotics.All strains are susceptible to vancomycin andβ-lactams susceptibility also remained high,but resistance to clindamycin,erythromycin,and tetracycline was high(>65%).The virulence genes scpB,cylB,fbsB,and cfb were highly prevalent(90%-100%),indicating their potential for vaccine and diagnostic development.Conclusions:Our findings provide valuable insights into GBS serotypes,resistance,and virulence factors,contributing to community monitoring,preventive measures,diagnostics,and vaccine development.However,the limited sample size necessitates further research.
基金supported by Research on Breeding and Healthy Breeding Technology of Xueyu White Chicken(mating line)in Tibet Science and Technology Program(XZ202101ZY0002N)the National Key R&D Program Project(2022YFD1600902-4)Sichuan Province Regional Innovation Cooperation Project(2023YFQ0050)。
文摘Bacterial infections of avian embryos can lead to an increase in embryo mortality,and the proliferation of antimicrobial-resistant bacteria aggravates the situation.A low hatching rate also poses a challenge to the population of artificially bred Crested Ibises(Nipponia nippon).This study aims to determine the potential association between bacterial infection and the death of Crested Ibis embryos,and whether there is convergence between antimicrobial resistance and virulence in strain.In this study,13 Escherichia coli and 12 Proteus mirabilis isolates were recovered from dead Crested Ibis embryos.The pathogenicity examination confirmed the pathogenicity of all isolates,and multiple virulence genes detected by PCR-sequencing demonstrated the presence of irp2 and iuc D(100%),fim C and iss(92.31%)in E.coli,and uca A(58.33%)in P.mirabilis.Antimicrobial susceptibility test demonstrated that isolates were mainly resistant to amoxicillin(E.coli:76.92%,P.mirabilis:91.67%),cefazolin(E.coli:76.92%,P.mirabilis:91.67%),oxytetracycline(E.coli:92.31%,P.mirabilis:75.00%)and sulfamethoxazole-trimethoprim(E.coli:53.85%,P.mirabilis:33.33%),and more than 30%of isolates showed multidrug-resistance(MDR).Further analyses detected extended-spectrumβ-lactamase(ESBL)genes,of which blaTEM-1(E.coli:100%,P.mirabilis:100%)had the highest frequency,followed by the blaCTX-M-55(E.coli:92.31%,P.mirabilis:50%),blaCTX-M-14(E.coli:76.92%,P.mirabilis:33.33%),blaCTX-M-65(E.coli:15.38%,P.mirabilis:16.67%),and all isolates were negative for blaSHV and blaOXA.Pearson's correlation analysis showed a positive correlation between the presence ofβ-lactam resistance and ESBL genes,while mainly negative correlations were observed between the presence of ESBL genes and virulence genes.Furthermore,the conjugation experiment and PFGE revealed that the isolates were primarily polyclonal,and there was horizontal transfer of resistance or virulence genes by plasmids.Based on the results,E.coli and P.mirabilis were responsible for embryonic mortality of the ibises in this study.The co-presence and co-transfer of ESBL genes and virulence genes can pose a potential threat to the health of the Crested Ibis,and measures such as prudent use of antimicrobials,and constant surveillance of resistance and pathogenicity,must be implemented at the Crested Ibis breeding base.
基金supported by National Natural Science Foundation of China,China(32170102)Natural Science Foundation of Tianjin(21JCYBJC01420)the Fundamental Research Funds for the Central Universities(63233050)。
文摘Objective Pseudomonas aeruginosa(P.aeruginosa)is a prevalent pathogenic bacterium involved in meningitis;however,the virulence factors contributing to this disease remain poorly understood.Methods The virulence of the P.aeruginosa A584,isolated from meningitis samples,was evaluated by constructing in vitro blood-brain barrier and in vivo systemic infection models.qPCR,whole-genome sequencing,and drug efflux assays of A584 were performed to analyze the virulence factors.Results Genomic sequencing showed that A584 formed a phylogenetic cluster with the reference strains NY7610,DDRC3,Pa58,and Pa124.Its genome includes abundant virulence factors,such as hemolysin,the Type IV secretion system,and pyoverdine.A584 is a multidrug-resistant strain,and its wide-spectrum resistance is associated with enhanced drug efflux.Moreover,this strain caused significantly more severe damage to the blood-brain barrier than the standard strain,PAO1.qPCR assays further revealed the downregulation of the blood-brain barrier-associated proteins Claudin-5 and Occludin by A584.During systemic infection,A584 exhibited a higher capacity of brain colonization than PAO1(37.1×10^(6) CFU/g brain versus 2.5×10^(6) CFU/g brain),leading to higher levels of the proinflammatory factors IL-1βand TNF-α.Conclusion This study sheds light on the virulence factors of P.aeruginosa involved in meningitis.
文摘Helicobacter pylori infection represents a widespread chronic condition with varying prevalence influenced by race, ethnicity, and geography. The severity of H. pylori-associated diseases is determined by an array of virulence factors. Although extensive studies have been conducted globally, data on the distribution of Helicobacter pylori virulence genes in Libya remain limited, constraining insights into the pathogenicity of local strains and hindering the development of targeted interventions. This study aimed to evaluate the prevalence of H. pylori infection, characterize essential virulence genes [vacA variants (s1/s2, m1/m2), cagA, and iceA1], and examine their association with gastroduodenal diseases among Libyan patients. Gastric biopsies from 144 participants were analyzed using polymerase chain reaction (PCR) assays, and risk factor data were collected via questionnaires. H. pylori was detected in 63.2% of samples by PCR. The vacA gene was present in 84.6% of cases, cagA in 58.2%, and iceA1 in 29.7%. Among vacA variants, s1 allele was most common (53.2%), followed by m1 (42.9%), m2 (37.7%), and s2 (13%) alleles. Significant associations were identified between specific virulence genes and the development of gastroduodenal diseases, highlighting their role in pathogenicity. This investigation is one of Libya’s first comprehensive assessments of H. pylori virulence factors, addressing a critical epidemiological gap. The high prevalence of virulence genes suggests their potential as disease biomarkers. These findings contribute to a deeper understanding of H. pylori pathogenicity within the Libyan population and establish a basis for future clinical interventions and public health strategies to manage and prevent H. pylori-associated diseases in Libya and comparable regions.
基金The Shandong Natural Science Foundation Youth Fund Project(ZR2022QC079,ZR2023QD024)provided funding for this work。
文摘Aeromonas veronii is considered an emerging food-borne pathogen associated with a significant threat to public health,distributed in various aquatic environments and products.Hanks-type serine/threonine kinases(STKs)play a critical role in the pathogenesis of pathogens.However,the function of A.veronii STKs is currently unclear.By constructing a markerless prk A in-frame deletion strain,Δprk A,we found that i)the colonies of theΔprk A strain were larger after 1 h of high temperature at 50℃compared with the wild-type strain TH0426 and the complementary strain C-prk A,and the number of viable bacteria of theΔprk A strain increased significantly;ii)theΔprk A strain significantly enhanced the adhesion ability to epithelioma papulosum cyprini(EPC)cells;iii)theΔprk A strain was significantly more virulent than the TH0426 strain,at both the cellular and animal levels;and iv)RNA-seq results showed a total of 984 differentially expressed genes(DEGs)between theΔprk A strain and the TH0426 strain,which were enriched in 70 Kyoto Encyclopedia of Genes and Genomes(KEGG)metabolic pathways,mainly involved in bacterial ribosomes,flagellar assembly,type Ⅱ secretion system(T2SS),and lipopolysaccharide metabolic pathways.Taken together,the findings of this study indicate that the Hanks-type STK Prk A negatively regulates several biological processes,such as the temperature tolerance and virulence of A.veronii.The results of this study provide an important reference for further elucidation of the pathogenesis of A.veronii.
基金supported by the National Natural Science Foundation of China(32072461)the Open Foundation of Shaanxi Key Laboratory of Plant Nematology,China(2021-SKL-01).
文摘The velvet protein family serves as a crucial factor in coordinating development and secondary metabolism in numerous pathogenic fungi.However,no previous research has examined the function of the velvet protein family in Fusarium oxysporum f.sp.niveum(FON),a pathogen causing a highly destructive disease in watermelon.In this study,∆fovel1 and∆folae1 deletion mutants and∆fovel1-C and∆folae1-C corresponding complementation mutants of FON were validated.Additionally,the phenotypic,biochemical,and virulence effects of the deletion mutants were investigated.Compared to the wild-type strains,the∆fovel1 and∆folae1 mutants exhibited altered mycelial phenotype,reduced conidiation,and decreased production of bikaverin and fusaric acid.Furthermore,their virulence on watermelon plant roots significantly decreased.All these alterations in mutants were restored in corresponding complementation strains.Notably,yeast two-hybrid results demonstrated an interaction between FoVel1 and FoLae1.This study reveals that FoVEL1 and FoLAE1 play essential roles in secondary metabolism,conidiation,and virulence in FON.These findings enhance our understanding of the genetic and functional roles of VEL1 and LAE1 in pathogenic fungi.
基金Supported by Agricultural Achievement Transformation Project of the Ministry of Science and Technology(2012GB2A200045)China Postdoctoral Science Foundation(20100470565)+1 种基金Science and Technology Support Program of Hebei Province(10960408D)Science and Technology Development Project of Qinhuangdao City(201101A182)~~
文摘[Objective] This study aimed to explore the presence of three causative genes Colv,Stxs and HlyE of the pathogenic E.coli from chickens,pigs and food.[Method] By using 44 E.coli strains from chickens,24 from pigs and 26 from food as the experimental materials,virulence genes Colv,Stxs（stx2,stx2e） and HlyE were detected with polymerase chain reaction（PCR） method.[Result] Among all the E.coli strains,the detection rate of Colv was 25% from chickens,4.2% from pigs,and 0 from food;the detection rate of Stx2（Stx2e） from all E.coli strains was 0;the detection rate of HlyE was 2.27% from chickens,0 from pigs,and 11.5% from food.[Conclusion] Virulence gene Colv shows relatively high carrying rate in E.coli from chickens and pigs;HlyE also shows a certain degree of presence in E.coli from chickens and food.
文摘Fungal pathogen of asparagus stem blight was isolated. No significant genetic difference was detected among the three strains with 492 bp long ITS1-5.8S-ITS2 sequence. It was then identified through colony growth, conidia morphology, and molecular characterization. The physiological response to oxidation and osmosis stress, and virulence to Asparagus officinalis L. were analyzed. The results showed that the pathogen causing asparagus stem blight for A. officinalis L. in Jiangxi Province is Phomopsis asparagri (Sacc.) Bubák. Under pure culture conditions, the conidia were oval-shaped (α-type), with colorless single spore and single nucleus, containing 0-2 oil balls. Its vegetative growth rate was higher when cultured on 0.2 × potato dextrose agar (0.2 × PDA) medium than that on oatmeal agar (OA) medium. However, the pycnidia appeared earlier on OA medium than on 0.2 earlier PDA medium. The vegetative growth rate was depressed under oxidation (H2O2) or osmosis (NaCl) stress conditions, and totally inhibited under 7 mmol/L H2O2 or 2.4 mol/L NaCl. All the strains caused typical pathogenic symptoms to Asparagus officinalis L. at 7 days-post-inoculation (dpi) with conidia.
文摘[ Objective] The paper was to screen Bacillus with strong antagonistic effect. [ Method] The diseased ginger and the surrounding soils were collected from Laiwu of Shandong Province, and the high-virulence strains of the pathogen of ginger blast （Ralstonia solanacearum） were isolated, Bacillus was used to carry out antagonistic test. [Result] Three strains LW-4, LW-7 and LW-32 had strong antagonistic effect against R. solanacearum, the area of their inhibition zone was larger than other strains. [ Conclusion] The study provided theoretical basis for the control of ginger blast.
文摘Helicobacter pylori(H.pylori)is one of the most important human pathogens,infecting approximately half of the global population.Despite its high prevalence,only a subset of H.pylori infected individuals develop serious gastroduodenal pathology.The pathogenesis of H.pylori infection and disease outcome is thus thought to be mediated by an intricate interplay between host,environmental and bacterial virulence factors.H.pylori has adapted to the harsh milieu of the human stomach through possession of various virulence genes that enable survival of the bacteria in the acidic environment,movement towards the gastric epithelium,and attachment to gastric epithelial cells.These virulence factors enable successful colonization of the gastric mucosa and sustain persistent H.pylori infection,causing chronic inflammation and tissue damage,which may eventually lead to the development of peptic ulcers and gastric cancer.Numerous studies have focused on the prevalence and role of putative H.pylori virulence genes in disease pathogenesis.While several virulence factors with various functions have been identified,disease associations appear to be less evident,especially among different study populations.This review presents key findings on the most important H.pylori virulence genes,including several bacterial adhesins and toxins,in children and adults,and focuses on their prevalence,clinical significance and potential relationships.
文摘Helicobacter pylori(H. pylori) is a model organism for understanding host-pathogen interactions and infection-mediated carcinogenesis. Gastric cancer and H. pylori colonization indicates the strong correlation. The progression and exacerbation of H. pylori infection are influenced by some factors of pathogen and host. Several virulence factors involved in the proper adherence and attenuation of immune defense to contribute the risk of emerging gastric cancer, therefore analysis of them is very important. H. pylori also modulates inflammatory and autophagy process to intensify its pathogenicity. From the host regard, different genetic factors particularly affect the development of gastric cancer. Indeed, epigenetic modifications, Micro RNA and long non-coding RNA received more attention. Generally, various factors related to pathogen and host that modulate gastric cancer development in response to H. pylori need more attention due to develop an efficacious therapeutic intervention. Therefore, this paper will present a brief overview of host-pathogen interaction especially emphases on bacterial virulence factors, interruption of host cellular signaling, the role of epigenetic modifications and non-coding RNAs.
基金Supported by The Polish Ministry of Science and Higher Education Grants No. 2 PO5A 094 29, 3 P05E 091 25, N N402 0861 and N N401 144638
文摘AIM: To determine the features of Enterococcus that contribute to the development and maintenance of the inflammatory process in patients with inflammatory bowel disease (IBD). METHODS: Multiplex polymerase chain reaction (PCR) was applied to assess the presence of genes that encode virulence factors [surface aggregating protein (asa1), gelatinase (gelE), cytolysin (cylA), extracellular surface protein (esp) and hyaluronidase (hyl)] in the genomic DNA of 28 strains of Enterococcus isolated from the intestinal tissues of children with IBD (n =16) and of children without IBD (controls; n = 12). Additionally, strains with confirmed presence of the gelE gene were tested by PCR for the presence of quorum sensing genes (fsrA, fsrB, fsrC) that control the gelatinase production. Gelatinase activity was tested on agar plates containing 1.6% gelatin. We also analysed the ability of Enterococcus strains to release and decompose hydrogen peroxide (using Analytical Merckoquant peroxide test strips) and tested their ability to adhere to Caco-2 human gut epithelium cells and form biofilms in vitro. RESULTS: A comparison of the genomes of Enterococcus strains isolated from the inflamed mucosa of patients with IBD with those of the control group showed statistically significant differences in the frequency of theasa1 gene and thegelE gene. Furthermore, the cumulative occurrence of different virulence genes in the genome of a single strain ofEnterococcus isolated from the IBD patient group is greater than in a strain from the control group, although no significant difference was found. Statistically significant differences in the decomposition of hydrogen peroxide and adherence to the Caco-2 epithelial cell line between the strains from the patient group and control group were demonstrated. The results also showed that profuse biofilm production was more frequent amongEnterococcus strains isolated from children with IBD than in control strains. CONCLUSION: Enterococcus strains that adhere strongly to the intestinal epithelium, form biofilms and possess antioxidant defence mechanisms seem to have the greatest influence on the inflammatory process.
基金supported by grants from the National Key Research and Development Program(2018YFC0840402)National Natural Science Foundation of China(31941002)+2 种基金Special Fund for Basic Scientific Research of Chinese Academy of Agricultural Sciences (Y2019YJ07-01)Science and technology innovation engineering major scientific research program of Chinese Academy of Agricultural Sciences (CAASZDRW202006-03)State Key Laboratory of Veterinary Etiological Biology Major achievements cultivation project of Chinese Academy of Agricultural Sciences (SKLVEB2020CGPY02)。
文摘African swine fever virus(ASFV)is the etiological agent of African swine fever(ASF),an often lethal disease in domestic and wild pigs.ASF represents a major threat to the swine industry worldwide.Currently,no commercial vaccine is available because of the complexity of ASFV or biosecurity concerns.Live attenuated viruses that are naturally isolated or genetically manipulated have demonstrated reliable protection against homologous ASFV strain challenge.In the present study,a mutant ASFV strain with the deletion of ASFV MGF-110-9L(ASFV-D9L)was generated from a highly virulent ASFV CN/GS/2018 parental strain,a genotypeⅡASFV.Relative to the parental ASFV isolate,deletion of the MGF-110-9L gene significantly decreased the ability of ASFV-D9L to replicate in vitro in primary swine macrophage cell cultures.The majority of animals inoculated intramuscularly with a low dose of ASFV-D9L(10 HAD50)remained clinically normal during the 21-day observational period.Three of five ASFV-D9L-infected animals displayed low viremia titers and low virus shedding and developed a strong virus-specific antibody response,indicating partial attenuation of the ASFV-D9L strain in pigs.The findings imply the potential usefulness of the ASFV-D9L strain for further development of ASF control measures.
