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@#Staphylococcus aureus is a common bacterial pathogen known to cause various kinds of infections due to its repertoire of virulence factors. This study aimed to investigate the distribution of 19 types of virulence genes among clinical isolates of methicillin-susceptible S. aureus (MSSA) using the polymerase chain reaction. A total of 109 MSSA isolates, i.e., 63 hospital-associated (HA) and 46 community-associated (CA) were collected from Hospital Sultanah Nur Zahirah, the main tertiary hospital in Terengganu, Malaysia, from July 2016 to June 2017. The most frequent virulence genes detected were hla (78.9%, n=86) and hld (78.0%, n=85) encoding hemolysins, lukED (56.9%, n=62) encoding leukotoxin ED, followed by seb (26.6%, n=29) and sea (24.8%, n=27) encoding enterotoxins. Among 34 (31.2%) isolates carrying six or more virulence genes, only five were multidrug resistant (MDR) while the remaining isolates were susceptible. Significant associations were discovered between the hld gene with CA-MSSA (p=0.016) and the seo gene with HA-MSSA (p=0.023). However, there is no significant association between virulence genes among the different types of infection. The clinical MSSA isolates in Terengganu showed high prevalence and high diversity of virulence gene carriage.
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Abstract Pakistan is an agricultural country and fisheries play a very important role in the economic development of the country. Different diseases are prevalent in Pakistani fish but information related to the causative agents is not well-known. Keeping in view the significance of bacterial pathogens as the causative agents of multiple fish diseases, the present study was conducted for identification, characterization and analysis of virulence genes of Aeromonas spp. isolated from diseased fishes. A total of fifty fish samples having multiple clinical indications were collected from different fish farms of district Kasur, Punjab Pakistan. For isolation of Aeromonas spp. samples were enriched and inoculated on Aeromonas isolation medium. Isolates were identified and characterized by different biochemical tests, Analytical Profile Index (API) 20E kit and Polymerase Chain Reaction (PCR) assays. All isolates were screened for three putative virulence genes including aerolysin (aer), haemolysin (hyl) and heat labile cytotonic enterotoxin (alt). Seven isolates of Aeromonas (A.) hydrophila were retrieved and identified based on API 20E. These isolates were further confirmed as A. hydrophila on the basis of PCR assays. Three isolates were detected positive for the presence of virulence genes (alt and hyl). Whereas aerolysin (aer) gene was not present in any of A. hydrophila isolates. The present study confirmed A. hydrophila as the causative agent of epizootic ulcerative syndrome and motile Aeromonas septicemia in fish farms of district Kasur, Punjab Pakistan. Moreover, detection of two virulence genes (alt and hyl) in A. hydrophila isolates is a threat for fish consumers of study area.
Resumo O Paquistão é um país agrícola, onde a pesca desempenha um papel muito importante para o desenvolvimento econômico. Diferentes doenças são prevalentes em peixes do Paquistão, mas as informações relacionadas aos agentes causadores não são bem conhecidas. Tendo em vista a importância dos patógenos bacterianos como agentes causadores de múltiplas doenças em peixes, o presente estudo foi conduzido para identificação, caracterização e análise de genes de virulência de isolados de Aeromonas spp. de peixes doentes. Foram coletadas 50 amostras de peixes com múltiplas indicações clínicas em diferentes fazendas do distrito de Kasur, Punjab, Paquistão. Para isolar Aeromonas spp., as amostras foram enriquecidas e inoculadas em meio de isolamento. Os isolados foram identificados e caracterizados por diferentes testes bioquímicos, kit Analytical Profile Index (API) 20E, e ensaios de reação em cadeia da polimerase (PCR). Todos os isolados foram selecionados para três genes de virulência putativos, incluindo aerolisina (aer), hemolisina (hyl) e enterotoxina citotônica termolábil (alt). Sete isolados de Aeromonas hydrophila foram recuperados e identificados com base no API 20E. Esses isolados foram posteriormente confirmados como A. hydrophila de acordo com ensaios de PCR. Três isolados indicaram a presença de genes de virulência (alt e hyl), enquanto o gene aerolisina (aer) não esteve presente em nenhum dos isolados de A. hydrophila. O presente estudo confirmou A. hydrophila como o agente causador da síndrome ulcerativa epizoótica e septicemia móvel por Aeromonas em fazendas de peixes, no distrito de Kasur, Punjab, Paquistão. Além disso, a detecção de dois genes de virulência (alt e hyl) em isolados de A. hydrophila é uma ameaça para os consumidores de peixes da área de estudo.
Subject(s)
Animals , Gram-Negative Bacterial Infections/veterinary , Gram-Negative Bacterial Infections/epidemiology , Aeromonas/genetics , Pakistan , Aeromonas hydrophila/genetics , Enterotoxins/genetics , FishesABSTRACT
Abstract Pakistan is an agricultural country and fisheries play a very important role in the economic development of the country. Different diseases are prevalent in Pakistani fish but information related to the causative agents is not well-known. Keeping in view the significance of bacterial pathogens as the causative agents of multiple fish diseases, the present study was conducted for identification, characterization and analysis of virulence genes of Aeromonas spp. isolated from diseased fishes. A total of fifty fish samples having multiple clinical indications were collected from different fish farms of district Kasur, Punjab Pakistan. For isolation of Aeromonas spp. samples were enriched and inoculated on Aeromonas isolation medium. Isolates were identified and characterized by different biochemical tests, Analytical Profile Index (API) 20E kit and Polymerase Chain Reaction (PCR) assays. All isolates were screened for three putative virulence genes including aerolysin (aer), haemolysin (hyl) and heat labile cytotonic enterotoxin (alt). Seven isolates of Aeromonas (A.) hydrophila were retrieved and identified based on API 20E. These isolates were further confirmed as A. hydrophila on the basis of PCR assays. Three isolates were detected positive for the presence of virulence genes (alt and hyl). Whereas aerolysin (aer) gene was not present in any of A. hydrophila isolates. The present study confirmed A. hydrophila as the causative agent of epizootic ulcerative syndrome and motile Aeromonas septicemia in fish farms of district Kasur, Punjab Pakistan. Moreover, detection of two virulence genes (alt and hyl) in A. hydrophila isolates is a threat for fish consumers of study area.
Resumo O Paquistão é um país agrícola, onde a pesca desempenha um papel muito importante para o desenvolvimento econômico. Diferentes doenças são prevalentes em peixes do Paquistão, mas as informações relacionadas aos agentes causadores não são bem conhecidas. Tendo em vista a importância dos patógenos bacterianos como agentes causadores de múltiplas doenças em peixes, o presente estudo foi conduzido para identificação, caracterização e análise de genes de virulência de isolados de Aeromonas spp. de peixes doentes. Foram coletadas 50 amostras de peixes com múltiplas indicações clínicas em diferentes fazendas do distrito de Kasur, Punjab, Paquistão. Para isolar Aeromonas spp., as amostras foram enriquecidas e inoculadas em meio de isolamento. Os isolados foram identificados e caracterizados por diferentes testes bioquímicos, kit Analytical Profile Index (API) 20E, e ensaios de reação em cadeia da polimerase (PCR). Todos os isolados foram selecionados para três genes de virulência putativos, incluindo aerolisina (aer), hemolisina (hyl) e enterotoxina citotônica termolábil (alt). Sete isolados de Aeromonas hydrophila foram recuperados e identificados com base no API 20E. Esses isolados foram posteriormente confirmados como A. hydrophila de acordo com ensaios de PCR. Três isolados indicaram a presença de genes de virulência (alt e hyl), enquanto o gene aerolisina (aer) não esteve presente em nenhum dos isolados de A. hydrophila. O presente estudo confirmou A. hydrophila como o agente causador da síndrome ulcerativa epizoótica e septicemia móvel por Aeromonas em fazendas de peixes, no distrito de Kasur, Punjab, Paquistão. Além disso, a detecção de dois genes de virulência (alt e hyl) em isolados de A. hydrophila é uma ameaça para os consumidores de peixes da área de estudo.
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@#Campylobacteriosis is a human infection primarily caused by Campylobacter jejuni and Campylobacter coli. Consumption of contaminated chicken and poultry products is the main mode of transmission. These bacteria possess virulence factors, including adhesins and toxins, which contribute to their pathogenesis. Moreover, their large genomes undergo frequent genetic recombination, resulting in a high degree of genetic diversity. However, limited information is available regarding the virulence and genotypic diversity profiles of these microorganisms in the Philippines. The objective of this study was to address this knowledge gap by characterizing Campylobacter isolates obtained from chicken offal sold in wet markets in Metro Manila, Philippines. Multilocus Sequence Typing (MLST) analysis was performed to determine the sequence types, resulting in the identification of 13 unique sequence types, including nine previously unreported ones, and three clonal complexes. Notably, the widespread sequence type ST-305 was found in samples from different markets. Furthermore, six isolates deposited in the Campylobacter PubMLST database were identified as C. coli based on allele profiles. Profiling using 10 selected virulence genes revealed that more than half of the isolates carried these genes. The most prevalent virulence gene was cadF (100%), followed by flaA (95%), racR, cdtA, cdtB, and cdtC (85%). The genes dnaJ and ceuE were also present in 75% of the isolates. Despite the limited sample size, the findings of this study reveal a significant level of genotypic diversity among the Campylobacter isolates. This diversity has important implications for source attribution studies and the identification of strains involved in campylobacteriosis outbreaks. Furthermore, the investigation of virulence factors associated with colonization and invasion of the avian gut can provide insights for the development of practical applications in Campylobacter control strategies. Understanding and addressing these factors are crucial steps toward mitigating the risk of Campylobacter infections and enhancing public health efforts.
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@#Abstract: Objective To understand the contamination status, drug resistance, virulence gene carrying status, and molecular typing characteristics of Vibrio parahaemolyticus (VP) in aquatic products sold in Nanchang City. Methods A total of 170 commercial crayfishes, freshwater fish frogs and related smears samples were collected from various farmers' markets in Nanchang from March to September 2021. The strains of V. parahaemolyticus were detected and isolated from the samples. Antibiotic resistance test, virulence gene test, and pulsed-field gel electrophoresis (PFGE) molecular typing analysis were carried out. Results Among the collected samples, V.parahaemolyticus was only isolated from crayfish and crayfish smear samples, with a total of 35 strains of VP isolated. No V.parahaemolyticus strain was isolated from other freshwater fish, frogs, and their smear samples. Among the 17 common antibiotics tested, only two trains showed resistance to ampicillin, and one strain to streptomycin, , and all were sensitive to other antibiotics; all 35 strains of V. parahaemolyticus carried the gene, but only one strain carried the heat-resistant related hemolysin gene trh, and no direct heat-resistant hemolysin gene tdh positive strain was found; PFGE pattern clustering showed that there was no strain with the same PFGE pattern, and there was no obvious dominant cluster among these strains, and their genetic relationship was relatively distant. Conclusions The contamination of V. parahaemolyticus in small and medium-sized crayfish sold in the market in Nanchang City is relatively serious. The V. parahaemolyticus isolates in these polluted crayfish generally do not carry key virulence genes such as tdh, are sensitive to common antibiotics, and only have low-level resistance to ampicillin and streptomycin. PFGE pattern clustering showed that V. parahaemolyticus does not have no obvious dominant cluster, and these strains have rich genetic diversity, indicating that they may have different sources.
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@#Abstract: Objective To investigate the antimicrobial activity of omadacycline (OMC) against clinical Streptococcus agalactiae (GBS) isolates, as well as its relationship with biofilm formation, resistance genes and virulence genes. Methods A total of 136 strains of Streptococcus agalactiae isolated from Shenzhen Nanshan People's Hospital between 2015 to 2020. The minimum inhibitory concentration (MIC) of OMC against Streptococcus agalactiae was determined by broth microdilution. Crystal violet staining was used to detect the biofilm formation ability of GBS. Resistance genes (tetM, tetO, tetK, ermB, OptrA) and virulence genes (cpsⅢ, bca, fbsA, cpsA, scpB) were investigated by polymerase chain reaction (PCR). Results Among the 136 clinical isolates of GBS, 20 strains (14.7%) were resistant to OMC, 64 (47.1%) were intermediate, and 52 (38.2%) were sensitive. Fifty-seven strains (41.9%) were biofilm-positive, 20 of which (35.1%) were sensitive to OMC. Seventy-nine strains (58.1%) were biofilm-negative, 32 of which (40.5%) were susceptible to OMC. There was a statistically significant difference in the sensitivity rates between the two groups of strains (χ2=63.062, P<0.001), but there was no significant difference in the sensitivity of OMC among the biofilm-positive strains (Fisher's exact test, P=0.824). The resistance rates of tetM, tetO, ermB and OptrA positive strains were higher than those of negative strains, while tetK was opposite. The presence of tetM (Z=0.815, P=0.415), tetO (Z=0.151, P=0.88), tetK (Z=0.567, P=0.571), ermB (Z=1.198, P=0.231) resistance genes in Streptococcus agalactiae had no significant impact on the sensitivity of OMC. However, the presence of the OptrA resistance gene showed a statistically significant effect on the sensitivity of OMC (Z=2.913, P=0.004). The virulence factors cpsⅢ, bca, fbsA, cpsA and scpB were all detected at a rate higher than 50%. The presence of the virulence genes cpsⅢ (Z=0.222, P=0.824), bca (Z=0.141, P=0.888), fbsA (Z=0.813, P=0.416), and cpsA (Z=1.615, P=0.106) in Streptococcus agalactiae had no significant impact on the sensitivity of OMC. However, there was a significant inter-group difference in the scpB virulence gene (Z=2.844, P=0.004), but the rank mean values and resistance rates of scpB-positive strains were lower than those of the negative strains. Conclusions The formation of biofilm in Streptococcus agalactiae reduces its sensitivity to OMC, but there was no significant difference in the sensitivity to OMC among the biofilm-positive strains. The presence of resistance genes tetM, tetO, tetK, ermB, and virulence genes cpsⅢ, bca, fbsA, cpsA, scpB in Streptococcus agalactiae is not associated with OMC resistance, but the presence of the resistance gene OptrA is correlated with OMC resistance..
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Objective:To investigate the distribution and molecular characteristics of Yersinia isolated from diarrhea patients in Jiangsu Province. Methods:From 2017 to 2021, the stool samples of diarrhea patients were collected in Tongshan District of Xuzhou City and Dongtai City of Yancheng City, Jiangsu Province, where the national active monitoring sites of Yersinia enterocolitica, then Yersinia was isolated; meanwhile, suspected Yersinia strains were collected from sentinel hospitals in the province. The DNA of isolated strains was extracted for whole genome resequencing, and the data were uploaded to the EnteroBase database for Yersinia species identification; the original data were cleaned and processed for 16S ribosomal RNA (16S rRNA) gene polymorphism analysis. Five virulence genes (ail, ystA, ystB, yadA, virF) were scanned through the National Center for Biotechnology Information (NCBI) and Pathogen Virulence Factor Database (VFDB), and K-mer Tree was constructed and genomic characteristics were analyzed. Results:From 2017 to 2021, a total of 2 058 stool samples from diarrhea patients were collected, and 57 strains of Yersinia were isolated and identified; meanwhile, two Yersinia strains were collected from the sentinel hospital. Compared with EnteroBase database, 51 strains were identified as Yersinia enterocolitica, 4 strains as Yersinia proxima, 1 strain each as Yersinia aleksiciae, Yersinia massiliensis, Yersinia intermedia and Yersinia canariae. The 16S rRNA gene polymorphism analysis showed that all strains were clustered into 3 groups, which could distinguish Yersinia enterocolitica from other Yersinia. Among the 51 strains of Yersinia enterocolitica, 49 strains were virulence genotype Ⅲ(ail-, ystA-, ystB+, yadA-, virF-), two strains were virulence genotype Ⅱ(ail+, ystA+, ystB-, yadA-, virF-); and 8 other Yersinia strains were virulence genotype Ⅳ (ail-, ystA-, ystB-, yadA-, virF-). K-mer analysis could distinguish Yersinia enterocolitica from other Yersinia, JS-XZ-2020001 strain was far away from other Yersinia enterocolitica isolates, and serotype O8 strains were more concentrated. Conclusions:The clinical isolates of Yersinia enterocolitica from diarrhea patients are mainly Yersinia and other Yersinia co-exist in a small amount in Jiangsu Province, two new Yersinia species ( Yersinia proxima and Yersinia canariae) are discovered. The virulence genotype of Yersinia enterocolitica is mainly type Ⅲ. The 16S rRNA gene polymorphism analysis and K-mer analysis can effectively distinguish Yersinia enterocolitica from other Yersinia.
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Objective To understand the research status of foodborne diseases in China from 1985 to 2022, and to explore the development process, research hotspots and frontier trends in this field. Methods With CNKI database as the search source, CiteSpace 6.1.R2 was used to analyze domestic research literature on foodborne diseases from 1985 to 2022. The author and organization cooperation map, and keyword co-occurrence and keyword timeline map were generated to comprehensively analyze the characteristics of foodborne diseases as well as research hotspots and cutting-edge trends in this field in China. Results A total of 2526 valid articles were obtained by exclusion criteria. According to the time distribution of articles from 1985-2022, the number of articles published before 2000 was small, and the annual number of articles published since 2000 had significantly increased. The largest number of articles was published by the China National Center for Food Safety Risk Assessment (51 articles), followed by the National Institution for Nutrition and Health of Chinese Center for Disease Control and Prevention (CDC) (38 articles). Most of the studies were conducted by national or government level research institutions in cooperation with provincial disease control and prevention centers. There was a close cooperation among different agencies. By the keyword cluster analysis, it was found that monitoring, Salmonella, and food safety were the concentrated research areas. The burst detection of keywords showed that food poisoning, sentinel hospital, and epidemic characteristics had the strongest citation burst. In recent years, the research hotspots were serotyping, drug resistance, virulence genes and so on. These keywords could reflect the investigation speed and laboratory level from a perspective. Conclusion The research on foodborne diseases in China is constantly increasing, and the research focus is gradually shifting from simple monitoring to improving the speed of outbreak investigation and laboratory level and speeding up the molecular tracing network to prevent more foodborne diseases.
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Objective:To analyze drug resistance, virulence and molecular epidemiological characteristics of Staphylococcus aureus ( S. aureus) isolated from skin sites of suppurative infections, and to provide an experimental basis for clinical anti-infective therapies. Methods:Swab samples from suppurative skin lesions and nasal secretions were collected from inpatients in Department of Dermatology, the Affiliated Hospital of Inner Mongolia Medical University from May 2020 to December 2020, and subjected to bacterial isolation and culture. Suspected S. aureus colonies were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Drug sensitivity test was conducted by using the broth microdilution method. Virulence genes of S. aureus were amplified by PCR, and real-time fluorescence-based quantitative PCR was performed to determine the relative expression of 4 virulence genes including tsst-1, pvl, hla and clfA in S. aureus strains from different sources. S. aureus strains were genotyped by multilocus sequence typing. Drug resistance rates and detection rates of virulence genes were compared by using chi-square test or Fisher′s exact test, and measurement data among groups were compared by using t test or Mann-Whitney U test. Results:A total of 85 strains of S. aureus were isolated from 210 inpatients, including 54 isolates from skin sites of suppurative infections (case group) and 31 isolates from the nasal cavity (control group) . Drug sensitivity test showed that 14 strains of methicillin-resistant S. aureus (MRSA) were identified among 85 strains of S. aureus. The resistance rate to penicillin was the highest (90.59%, 77/85) in the 85 S. aureus strains; the resistance rates to clindamycin and erythromycin were 60.00% (51/85) and 61.18% (52/85) respectively; no strains showed resistance to rifampicin, vancomycin or linezolid. PCR showed that the detection rate of the pvl gene was 33.33% (18/54) in the case group, which was significantly higher than that in the control group (12.90%, 4/31; χ2= 4.28, P= 0.038) . Real-time fluorescence-based quantitative PCR showed that the relative expression level of the clfA gene was significantly higher in the control group (3.87[2.30, 5.94]) than in the case group (1.63[0.95, 2.62], P= 0.007) . A total of 17 ST types were identified among the 85 strains of S. aureus, and the dominant types were ST398-methicillin-susceptible S. aureus (20/71) and ST22-MRSA (9/14) . The detection rate of the virulence gene pvl was significantly higher in the ST22-MRSA strain (14/14) than in the non-ST22 MRSA strains (0, P < 0.001) . Conclusions:S. aureus strains isolated from the skin sites of suppurative infections were highly resistant to penicillin, clindamycin and erythromycin, so these antibiotics should not be used as the first-choice empiric treatment. The occurrence of cutaneous S. aureus infections may be associated with the virulence gene pvl, and the nasal colonization of S. aureus may be associated with the clfA gene.
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Aims@#Helicobacter pylori is a gastrointestinal bacterium that causes peptic ulcers and stomach cancer in nearly half of the world’s population. Many virulence factors influence the outcome of H. pylori related disorders. The purpose of this study was to see if there was a relationship between H. pylori virulence factors and histological and endoscopic findings in stomach biopsy specimens from Sudanese gastritis patients.@*Methodology and results@#In the period between March 2018 and January 2020, a total of 290 gastric biopsies were taken from patients in Khartoum State hospitals. Histopathology and polymerase chain reaction (PCR) assays were performed on all specimens. Histological investigation revealed H. pylori in 103/290 (35.5%) samples, while PCR revealed H. pylori 16S rRNA positivity in 88/290 (30.3%) samples. Eighty-eight positive PCR specimens were subjected to PCR for genotypic detection of cagA, cagE, vacA, dupA and iceA1 genes. All of strains were vacA positive 100% (88/88) followed by dupA 50.0% (44/88), cagA 40.9% (36/88), cagE gene 38.6% (34/88) and iceA1 gene was detected in only 15.9% (14/88). The vacA s1/m1 68.2% (60/88) was the most prevalent vacA subtype.@*Conclusion, significance and impact of study@#Helicobacter pylori virulence genes were widespread and diversified in Sudanese gastritis patients. Helicobacter pylori cagA and iceA1 were significantly in association with gastric mucosa inflammation degree, whereas the dupA gene was found to be associated with the clinical outcomes.
Subject(s)
Helicobacter pylori , GastritisABSTRACT
Aims@#Salmonella is one of the most common foodborne illnesses worldwide. Poultry meat and products are the main sources of human infection. Therefore, the main objective of the current study was to assess the genetic virulence of biofilm-forming Salmonella isolated from chicken sausage and nuggets.@*Methodology and results@#Isolation of Salmonella was carried out using XLD agar; suspected colonies were identified biochemically and then serotyped using the Kauffman-White scheme for detection of somatic (O) and flagellar (H) antigens. Congo red (CR) medium was used for the assessment of biofilm formation of the isolated strains. The invasion gene (invA), the heat-labile Salmonella enterotoxin gene (stn), plasmid-encoded fimbriae (pefA) genes, the protein effectors sopB, sopD and biofilm genes in six Salmonella isolates were investigated using mPCR, following QIAamp® DNA Mini Kit instructions and 1.5% agarose gel electrophoreses. Salmonella was detected in 12%, 8% and 4% of the examined frozen packaged raw chicken sausage, frozen packaged raw chicken nuggets and ready-to-eat sausage. The isolated strains were S. Typhimurium, S. Enteritidis, S. Essen and S. Montevideo. Moreover, mPCR indicated the presence of biofilm gene (csgD gene), stn, sopB and sopD virulence genes in all isolated strains (100%); however, pefA gene failed to be detected.@*Conclusion, significance and impact of study@#The current findings showed that every Salmonella isolate examined was capable of creating biofilm at room temperature. As a result, these isolates are more likely to persist on abiotic surfaces, which raises the danger of cross-contamination and foodborne outbreaks.
Subject(s)
Salmonella Food PoisoningABSTRACT
Abstract The aim of present study is to characterize the resistance and virulence profile of enterococci isolated from aquaculture excavated ponds and masonry tanks (6 samples) in southern Brazil. Samples were cultured in selective medium, 10 colonies were randomly selected from each sample, which were identified by MALDI-TOF and tested against 13 antimicrobials. The presence of resistance (tetL, tetM, tetS, ermB and msrC) and virulence (ace, esp, agg, cylA and gelE) genes were determined by PCR. A total of 79 enterococci were identified, and Entecococcus faecalis (44.3%) and E. casseliflavus (36.7%) were the most prevalent species isolated. Sixty-five strains (82.3%) were resistant to at least one of the antimicrobials tested, whereas 27 (34.2%) strains were multiresistant. The overall percentages of antimicrobial resistant isolates were: 58.2% to rifampicin, 40.5% to fluoroquinolones, 36.7% to erythromycin and 30.4% to tetracycline. The tetL and tetM genes were found in 57.7% of the tetracycline-resistant strains; and msrC in 31.01% of erythromycin-resistant strains. The most frequently detected virulence factors were ace and gelE genes. Although limited to a single farm, these data suggest that aquaculture may be a reservoir of resistant and virulent enterococci. This study is the first step towards enhancing our understandingof distribution, resistance and virulence profile in enterococci isolated from fish farming environments in the south Brazil.
Resumo O objetivo do estudo apresentado é caracterizar o perfil de resistência e virulência de enterococos isolados de viveiros escavados e tanques de alvenaria (6 amostras) de uma pisicultura no Sul do Brasil. As amostras foram cultivadas em meio seletivo, 10 colônias foram selecionadas aleatoriamente de cada amostra, que foram identificadas por MALDI-TOF e testadas contra 13 antimicrobianos. A presença de genes de resistência (tetL, tetM, tetS, ermB e msrC) e virulência (ace, esp, agg, cylA e gelE) foi determinada por PCR. Foram identificados 79 enterococos, sendo Entecococcus faecalis (44,3%) e E. casseliflavus (36,7%) as espécies mais frequentes isoladas. Sessenta e cinco cepas (82,3%) eram resistentes a pelo menos um dos antimicrobianos testados, enquanto 27 (34,2%) eram multirresistentes. As porcentagens gerais de isolados resistentes a antimicrobianos foram: 58,2% para rifampicina, 40,5% para fluoroquinolonas, 36,7% para eritromicina e 30,4% para tetraciclina. Os genes tetL e tetM foram encontrados em 57,7% das cepas resistentes à tetraciclina; e msrC em 31,01% das cepas resistentes à eritromicina. Os fatores de virulência mais comumente detectados foram ace e gelE. Embora limitados a uma única fazenda, esses dados indicam que a aquicultura pode ser uma fonte de enterococos resistentes e virulentos. Este estudo é o primeiro passo para melhorar nosso entendimento da distribuição, resistência e perfil de virulência em enterococos isolados de ambientes de piscicultura no sul do Brasil.
Subject(s)
Animals , Enterococcus/genetics , Drug Resistance, Bacterial/genetics , Brazil , Microbial Sensitivity Tests , AgricultureABSTRACT
ABSTRACT BACKGROUND: The Prex2 protein is a member of the Rac family proteins that belongs to small G proteins with a critical role in cell migration, cell proliferation, and apoptosis through its effects on PI3K cell signaling pathway and phosphatase activity of PTEN protein. The effect of PREX2 gene expression has been shown in some cancer cells. A survey of PREX2 gene expression in gastric antral epithelial cells of gastric cancer patients with Helicobacter pylori various genotypes infection can conduct to better understanding H. pylori infection's carcinogenesis. METHODS: In a case-control study, PREX2 gene expression was evaluated in gastric antral biopsy samples on four groups of patients referred to Sanandaj hospitals, including gastritis with (n=23) and without (n=27) H. pylori infection and gastric cancer with (n=21) and without (n=32) H. pylori infection. Each gastric biopsy sample's total RNA was extracted and cDNA synthesized by using Kits (Takara Company). The PREX2 gene expression was measured using the relative quantitative real-time RT-PCR method and ΔΔCt formula. RESULTS: The PREX2 gene expression increased in gastric antral biopsy samples of gastritis and gastric cancer patients with H. pylori infection (case groups) than patients without H. pylori infection (control groups) 2.38 and 2.27 times, respectively. The patients with H. pylori vacA s1m1 and sabB genotypes infection showed a significant increase of PREX2 gene expression in gastric cancer antral epithelial cells. CONCLUSION: H. pylori vacA s1m1 and sabB genotypes have the positive correlations with PREX2 gene expression in gastric antral epithelial cells of gastritis and gastric cancer patients.
RESUMO CONTEXTO: A proteína Prex2 é membro das proteínas da família Rac que pertencem a pequenas proteínas G com um papel crítico na migração celular, na proliferação celular e na apoptose através de seus efeitos na via de sinalização celular PI3K e atividade fosfatase da proteína PTEN. O efeito da expressão genética PREX2 tem sido mostrada em algumas células cancerosas. Um levantamento da expressão genética PREX2 em células epiteliais antrais gástricas de pacientes infectados com vários genótipos de Helicobacter pylori pode conduzir a um melhor entendimento da carcinogênese da infecção por H. pylori. MÉTODOS: Em estudo de caso-controle, a expressão genética PREX2 foi avaliada em amostras de biópsia antral gástrica em quatro grupos de pacientes encaminhados aos hospitais de Sanandaj, incluindo gastrite com (n=23) e sem (n=27) infecção por H. pylori e de câncer gástrico com (n=21) e sem (n=32) infecção por H. pylori. O RNA total de cada amostra de biópsia gástrica foi extraído e cDNA sintetizado por meio de kits (Takara Company). A expressão genética PREX2 foi medida utilizando-se o método RT-PCR em tempo real quantitativo relativo e a fórmula ΔΔCt. RESULTADOS: A expressão genética PREX2 aumentou em amostras de biópsia antral gástrica de pacientes com gastrite e câncer gástrico com infecção por H. pylori (grupos de casos) em relação aos sem infecção por H. pylori (grupos de controle) 2,38 e 2,27 vezes, respectivamente. Os pacientes com infecção por genótipos H. pylori vacA s1m1 e sabB apresentaram um aumento significativo da expressão genética PREX2 em células epiteliais antrais de câncer gástrico. CONCLUSÃO: Os genótipos H. pylori vacA s1m1 e sabB têm correlações positivas com a expressão genética PREX2 em células epiteliais antrais gástricas de pacientes com câncer gástrico e gastrites.
Subject(s)
Humans , Helicobacter Infections , Guanine Nucleotide Exchange Factors/genetics , Gastritis/genetics , Gastritis/microbiology , Case-Control Studies , Helicobacter pylori , Epithelial Cells/metabolism , Epithelial Cells/microbiology , Gastric MucosaABSTRACT
BACKGROUND: Brucella canis is the etiological agent of canine brucellosis, a worldwide neglected zoonosis that constitutes one of the major infectious causes of infertility and reproductive failure in dogs. Although genomic information available for this pathogen has increased in recent years, here we report the first genome sequencing of a B. canis strain in Chile, and the differences in virulence genes with other B. canis strains. RESULTS: Genome assembly produced a total length of 3,289,216 bp, N50 of 95,163 and GC% of 57.27, organized in 54 contigs in chromosome I, and 21 contigs in chromosome II. The genome annotation identified a total of 1981 CDS, 3 rRNA and 36 tRNA in chromosome I, and 1113 CDS and 10 tRNA in chromosome II. There is little variation between the different strains and the SCL isolate. Phylogenetic analysis showed that the Chilean SCL strain is closely related to B. canis and B. suis strains. Small differences were found when compared to the Serbian isolate, but all strains shared the same recent common ancestor. Finally, changes in the sequence of some virulence factors showed that the SCL strain is similar to other South American B. canis strains. CONCLUSIONS: This work sequenced and characterized the complete genome of B. canis strain SCL, evidencing the complete presence of all the genes of the virB operon, and minor changes in outer membrane proteins and in the urease operon. Our data suggest that B. canis was introduced from North America and then spread throughout the South American continent.
Subject(s)
Animals , Dogs , Brucellosis/epidemiology , Brucella canis/genetics , Brucella canis/pathogenicity , Urease/genetics , Brucellosis/transmission , Zoonoses , Chile , GenomeABSTRACT
Pathogenic Yersinia enterocolitica (Y. enterocolitica) is one of the food-borne entero-pathogen responsible for yersiniosis in humans. The purpose of this research was to survey the prevalence, virulence-associated genes, and antimicrobial resistance of Y. enterocolitica isolated from meat and meat product samples in Egypt. Forty-one (5.9%) out of 700- samples of chicken meat, beef, ground beef, and sausage were positive Y. enterocolitica with a high prevalence in chicken meat (12%). Five virulence genes (ail, inv, ystA, ystB, and yadA) were characterized among 41 Y. enterocolitica isolates with variable frequencies. Among the strains tested, the ystB gene was detected with a high percentage (78.1%), followed by inv gene (70.7%), ail gene (14.6%), ystA gene (12.2%), and yadA gene (2.4%). A high resistance rate was estimated to amoxicillin-clavulanic acid (100%), followed by cefazolin (95%), ampicillin (65.9%), and doxycycline (51.2%), whilst a high sensitivity rate was observed to gentamicin and ciprofloxacin (97.6% each). Interestingly, the multidrug resistance was specified in the 70.7% of strains and showing 13 resistance patterns. Based on nucleotide sequence analysis of the 16s rRNA gene, the phylogenetic tree showed the genetic relatedness amongst Y. enterocolitica isolates. These findings highlighted the emergence of virulent and multidrug-resistant pathogenic Y. entrocolitica in retailed meat and meat products in Egypt.
A Yersinia enterocolitica patogênica (Y. enterocolitica) é um dos enteropatógenos de origem alimentar responsáveis pela yersiniose no ser humano. O objetivo desta pesquisa foi avaliar a prevalência, genes associados à virulência e resistência antimicrobiana de Y. enterocolitica isolada de amostras de carne e produtos à base de carne no Egito. Quarenta e um (5,9%) de 700 amostras de carne de frango, carne bovina, moída e linguiça foram Y. enterocolitica positivas, com alta prevalência em carne de frango (12%). Cinco genes de virulência (ail, inv, ystA, ystB e yadA) foram caracterizados entre 41 isolados de Y. enterocolitica com frequências variáveis. Entre as cepas testadas, o gene ystB foi detectado com uma alta porcentagem (78,1%), seguido pelo gene inv (70,7%), ail genes (14,6%), gene ystA (12,2%) e gene yadA (2,4%). Foi estimada uma alta taxa de resistência ao ácido amoxicilina-clavulânico (100%), seguida de cefazolina (95%), ampicilina (65,9%) e doxiciclina (51,2%), enquanto uma alta taxa de sensibilidade foi observada para gentamicina e ciprofloxacina (97,6% cada). Curiosamente, a resistência a múltiplas drogas foi especificada em 70,7% das cepas e mostrando 13 padrões de resistência. Com base na análise da sequência nucleotídica do gene rRNA 16s, a árvore filogenética mostrou a relação genética entre isolados de Y. enterocolitica. Esses achados destacaram o surgimento de Y. entrocolitica patogênica virulenta e multirresistente em carnes e produtos à base de carne no Egito.
Subject(s)
Humans , Yersinia enterocolitica/genetics , Drug Resistance, Bacterial/genetics , Meat/microbiology , Meat Products/microbiology , Phylogeny , Virulence/genetics , RNA, Ribosomal, 16S , Egypt , Genotype , Anti-Bacterial Agents/pharmacologyABSTRACT
Objective:To construct a transposon mutation library and screen new virulence genes of hypervirulent Klebsiella pneumoniae(hvKp). Methods:The transposon mutation library was constructed and treated with human serum. The changes in the abundance of the genes of library mutant strains were analyzed by Transposon sequencing (Tn-seq). Besides, KEGG (kyoto encyclopedia of genes and genomes) annotation and enrichment analysis were performed on the screened genes.Results:A total of 405 genes were screened out according to the abundance of the genes in the library treated with human serum was 20% lower than that without treated, and 351 genes, 86.7% of these genes were conserved in HS11286, NJST258_1, NTUH-K2044 and RJF293. Ten genes existed in strains NTUH-K2044 and RJF293 with high virulence, while these genes were absent in HS11286 and NJST258_1 with low virulence. The mutants with genes such as glycosyl transferase gene wzy, aggregator protein gene wzi and capsule transporter gene wza, which belong to the capsule polysaccharide gene clusters, could not be detected after serum treatment. The abundance of iron carriers gene clusters such as aerobacterin and salmonellin in each library changed less than one time. KEGG annotation results showed that most annotated genes were involved in amino acid metabolism, cofactor and vitamin metabolism, carbohydrate metabolism, etc. Conclusions:Tn-seq is a reliable method to screen functional genes. In this study, 405 candidate virulence genes of hvKp were successfully screened out, providing an experimental basis for further research on the function and regulation mechanism of new virulence genes of hvKp.
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@#Background: Streptococcus pyogenes has a variety of virulence factors and the predominant invasive strains differ according to specific emm types and geographical orientation. Although emm typing is commonly used as the gold standard method for the molecular characterisation, multilocus sequence typing (MLST) has become an important tool for comparing the genetic profiles globally. This study aimed to screen selected virulence genes from invasive and non-invasive clinical samples and to characterise the molecular epidemiology by emm typing and MLST methods. Materials and Methods: A total of 42 S. pyogenes isolates from invasive and non-invasive samples collected from two different tertiary hospitals were investigated for the distribution of virulence factors and their molecular epidemiology by emm and multilocus sequence typing methods. Detection of five virulence genes (speA, speB, speJ, ssa and sdaB) was performed using multiplex polymerase chain reaction (PCR) using the standard primers and established protocol. Phylogenetic tree branches were constructed from sequence analysis utilised by neighbour joining method generated from seven housekeeping genes using MEGA X software. Results: Multiplex PCR analysis revealed that sdaB/speF (78.6%) and speB (61.9%) were the predominant virulence genes. Regardless of the type of invasiveness, diverse distribution of emm types/subtypes was noted which comprised of 27 different emm types/subtypes. The predominant emm types/subtypes were emm63 and emm18 with each gene accounted for 11.8% whereas 12% for each gene was noted for emm28, emm97.4 and emm91. The MLST revealed that the main sequence type (ST) in invasive samples was ST402 (17.7%) while ST473 and ST318 (12% for each ST) were the major types in non-invasive samples. Out of 18 virulotypes, Virulotype A (five genes, 55.6%) and Virulotype B (two genes, 27.8%) were the major virulotypes found in this study. Phylogenetic analysis indicated the presence of seven different clusters of S. pyogenes. Interestingly, Cluster VI showed that selected emm/ST types such as emm71/ST318 (n=2), emm70.1/ST318 (n=1), emm44/ST31 (n=1) and emm18/ST442 (n=1) have clustered within a common group (Virulotype A) for both hospitals studied. Conclusion: The present study showed that group A streptococcci (GAS) are genetically diverse and possess virulence genes regardless of their invasiveness. Majority of the GAS exhibited no restricted pattern of virulotypes except for a few distinct clusters. Therefore, it can be concluded that virulotyping is partially useful for characterising a heterogeneous population of GAS in hospitals.
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Resumen Introducción: La diferencia entre los aislados patógenos y comensales de Escherichia coli se fundamenta en sus antecedentes filogenéticos. En Venezuela son escasos los estudios que describen el potencial patogénico de los grupos filogenéticos en E. coli. Objetivo: Relacionar la susceptibilidad antimicrobiana, distribución de los grupos filogenéticos y genes de virulencia en cepas de E. coli uropatógena (ECUP) aisladas de pacientes con infección del tracto urinario. Materiales y Métodos: Se estudiaron 17 cepas de ECUP, aisladas de pacientes adultos hospitalizados en dos instituciones de salud. La susceptibilidad frente a ocho antimicrobianos se determinó por el método de microdilución en caldo (MDC). Las β-lactamasas de espectro extendido (BLEE) y carbapenemasas fueron detectadas fenotípicamente. Los grupos filogenéticos y la detección de los genes de virulencia se determinaron por reacción de polimerasa en cadena. Resultados: Todas las cepas sintetizaban BLEE y de éstas, 41% se asoció a la producción de una carbapenemasa (KPC o MBL). El filogrupo B2 (41%) fue predominante. Los genes de virulencia más frecuentes fueron fimH y fyuA con 82% cada uno. Sólo un aislado clasificado en el filogrupo F fue positivo al conjunto de seis genes estudiados. Discusión: La diversidad de asociaciones entre genes de virulencia y perfiles de resistencia, en las cepas ECUP evolucionan continuamente. Además, su distribución en los distintos grupos filogenéticos depende en gran medida de las características clínico epidemiológicas de los grupos de estudios.
Abstract Background: The difference between the pathogenic isolates and commensals of Escherichia coli is based on their phylogenetic antecedents. In Venezuela there are few studies that describe the pathogenic potential of phylogenetic groups in E. coli. Aims: Relate antimicrobial susceptibility, distribution of phylogenetic groups and virulence genes in strains of uropathogenic E. coli (ECUP) isolated from patients with UTI. Methods: We studied 17 ECUP strains, isolated from adult patients hospitalized in two health institutions. The susceptibility to 8 antibiotics was determined by the broth microdilution (MDC) method. Extended spectrum β-lactamases (ESBL) and carbapenemases were phenotypically detected. The phylogenetic groups and the detection of the virulence genes were determined by PCR. Results: All strains synthesized ESBL and of these, 41% were associated with the production of a carbapenemases (KPC or MBL). The phylogroup B2 (41%) was the most predominant. The most frequent virulence genes were fimH and fyuA with 82% each. Only one strain from group F was positive to the 6 genes studied. Discussion: The diversity of associations between virulence genes and resistance profiles in the ECUP are evolving continuously, their distribution in the different phylogenetic groups depends to a large extent on the clinical epidemiological characteristics of the study groups.
Subject(s)
Humans , Adult , Escherichia coli Infections , Uropathogenic Escherichia coli/genetics , Phylogeny , Urinary Tract Infections , Venezuela , beta-Lactamases , Virulence Factors , Anti-Bacterial AgentsABSTRACT
A total of 4378 cattle and buffalo were screened during period of study (July 2018-June 19). Out of which 27 Pseudomonas aeruginosa were isolated. The isolates were confirmed phenotypically based on pigment production on nutrient agar. These were then confirmed by PCR amplification of species specific oligonucleotide sequences. All the 27 isolates amplified 956bp amplicon 16srRNA Pseudomonas aeruginosa species specific nucleotide sequence. The isolates were also checked for exo and aglD virulence associated genes. All of them amplified 540bp and 313bp amplicon of exo gene and aglD gene. All the isolates were subjected to antibiotic sensitivity testing. Most of the isolates showed highest sensitivity for levofloxacin, streptomycin and enrofloxacin followed by gentamicin, moxifloxacin and amikacin. Neomycin, cefoperazone and ceftriaxone were intermediate in action
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Salmonella Infantis is frequently associated with human infections worldwide and is transmitted by consumption of contaminated foods, particularly those of animal origin, especially the chicken meat. We aimed to evaluate virulence characteristics, antimicrobial resistance and the genetic similarity of 51 strains of S. Infantis isolated from samples of poultry origin. The strains were isolated from 2009 to 2010 in a company with full cycle of broiler's production in the state of São Paulo, Brazil. The antimicrobial susceptibility test was performed and, by PCR, we evaluated the presence of the genes lpfA (hem-adhesion), agfA (hem-biofilm) and sefA (hem-adhesion) and resistance genes to beta-lactams (blaTEM, blaSHV, bla CTX-M and blaAmpC ). The phylogenetic relationship was determined by RAPD-PCR method. Among the drugs tested, the highest percentages of resistance were to amoxicillin (35.3%) and to sulfonamide (15.7%). Eleven antimicrobial resistance patterns were identified (A1 to A11), none of them presented a multiresistance profile (> 3 antimicrobials classes). There was 100% of positivity for the agfA gene, 92.2% for the lpfA gene, and no strain presented the sefA gene. Most of the isolates showed similarities in virulence potential, since they were simultaneously positive for two studied genes, agfA and lpfA (92.2%, 47/51). Of the 18 (35.3%) strains resistant to antimicrobials of the β-lactam class, 10 (55.5%) were positive to blaAmpC gene, five (27.8%) for blaCTX-M , two (11.1%) to blaSHV and no strain presented the blaTEM gene. The phylogenetic evaluation has shown the presence of five clusters (A, B, C, D and E) with similarity greatSalmonella Infantis is frequently associated with human infections worldwide and is transmitted by consumption of contaminated foods, particularly those of animal origin, especially the chicken meat. We aimed to evaluate virulence characteristics, antimicrobial resistance and the genetic similarity of 51 strains of S. Infantis isolated from samples of poultry origin. The strains were isolated from 2009 to 2010 in a company with full cycle of broiler's production in the state of São Paulo, Brazil. The antimicrobial susceptibility test was performed and, by PCR, we evaluated the presence of the genes lpfA (hem-adhesion), agfA (hem-biofilm) and sefA (hem-adhesion) and resistance genes to beta-lactams (blaTEM, blaSHV, bla CTX-M and blaAmpC ). The phylogenetic relationship was determined by RAPD-PCR method. Among the drugs tested, the highest percentages of resistance were to amoxicillin (35.3%) and to sulfonamide (15.7%). Eleven antimicrobial resistance patterns were identified (A1 to A11), none of them presented a multiresistance profile (> 3 antimicrobials classes). There was 100% of positivity for the agfA gene, 92.2% for the lpfA gene, and no strain presented the sefA gene. Most of the isolates showed similarities in virulence potential, since they were simultaneously positive for two studied genes, agfA and lpfA (92.2%, 47/51). Of the 18 (35.3%) strains resistant to antimicrobials of the ß-lactam class, 10 (55.5%) were positive to blaAmpC gene, five (27.8%) for blaCTX-M , two (11.1%) to blaSHV and no strain presented the blaTEM gene. The phylogenetic evaluation has shown the presence of five clusters (A, B, C, D and E) with similarity greater than 80%, and three distinct strains which were not grouped in any cluster. Cluster B grouped 33 strains, all positive for lpfA and agfA genes, from both, the broiler farming facility and the slaughterhouse, persistent throughout all the study period. This cluster also grouped 18 strains clones with genetic similarity greater than 99%, all isolated in the slaughterhouse. The presence of virulence genes associated with persistent strains clones for a long period, warns to the possibility of S. Infantis to form biofilm, and should be constantly monitored in broilers' production chain, in order to know the profile of the strains that may contaminate the final product and evaluate the hazards that represents to public health.er than 80%, and three distinct strains which were not grouped in any cluster. Cluster B grouped 33 strains, all positive for lpfA and agfA genes, from both, the broiler farming facility and the slaughterhouse, persistent throughout all the study period. This cluster also grouped 18 strains clones with genetic similarity greater than 99%, all isolated in the slaughterhouse. The presence of virulence genes associated with persistent strains clones for a long period, warns to the possibility of S. Infantis to form biofilm, and should be constantly monitored in broilers' production chain, in order to know the profile of the strains that may contaminate the final product and evaluate the hazards that represents to public health.(AU)
Salmonella Infantis é frequentemente associada a infecções humanas no mundo todo sendo transmitida pelo consumo de alimentos contaminados, principalmente aqueles de origem animal, com destaque para a carne de frango. Objetivou-se avaliar características de virulência, resistência antimicrobiana e a similaridade genética de 51 estirpes de S. Infantis isoladas em amostras de origem avícola. As estirpes foram isoladas no período de 2009 a 2010 em uma empresa com ciclo completo de produção de frango de corte, localizada no estado de São Paulo, Brasil. Foi realizado o teste de susceptibilidade antimicrobiana e pela técnica de PCR, foi avaliada a presença dos genes lpfA (fímbria-adesão), agfA (fímbria-biofilme) e sefA (fímbria-adesão) e os genes de resistência aos beta-lactâmicos (bla TEM, blaSHV, blaCTX-M e blaAmpC ). A relação filogenética foi determinada pelo método de RAPD-PCR. Dentre as drogas testadas, os maiores percentuais de resistência foram para amoxacilina com 35,3% e sulfonamida com 15,7%. Onze perfis de resistência aos antimicrobianos foram identificados (A1 a A11), sendo que nenhum deles apresentou perfil de multirresistência (>3 classes de antimicrobianos). Houve 100% de positividade para o gene agfA, 92,2% para o gene lpfA e nenhuma estirpe apresentou o gene sefA. A maioria dos isolados apresentaram semelhanças no potencial de virulência, pois foram positivos simultaneamente para dois genes estudados, agfA e lpfA (92,2% - 47/51). Das 18 (35,3%) estirpes resistentes aos antimicrobianos da classe dos ß-lactâmicos, 10 (55,5%) foram positivas para o gene blaAmpC , cinco (27,8%) para blaCTX-M , duas (11,1%) para blaSHV e nenhuma estirpe apresentou o gene bla TEM . A avaliação filogenética demonstrou a presença de cinco clusters (A, B, C, D e E) com similaridade superior a 80%, e três estirpes distintas que não foram agrupadas em nenhum dos clusters. O cluster B agrupou 33 estirpes, todas positivas para os genes lpfA e agfA, provenientes tanto do aviário quanto do matadouro frigorífico, persistentes durante todo o período do estudo. Este cluster ainda agrupou 18 estirpes clones com similaridade genética superior a 99%, todas isoladas no matadouro frigorífico. A presença dos genes de virulência, associada à persistência das estirpes clones durante um longo período do estudo, alertam para a possibilidade de S. Infantis em formar biofilme, devendo ser constantemente monitorada na cadeia de produção avícola, especialmente no ambiente de abate, de forma a conhecer o perfil das estirpes que podem contaminar o produto final e assim avaliar os perigos que representam para a saúde pública.(AU)