scholarly journals Investigation of Virulence Genes of Staphylococcus aureus Isolated from Sterile Body Fluid Samples and Their Correlation with Clinical Symptoms and Outcomes

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Tao Lin ◽  
Qianhui Li ◽  
Defu Jin ◽  
Wanbo Liu ◽  
Chaogui Tang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Body Fluid ◽  
Virulence Genes ◽  
Clinical Symptoms ◽  
Virulence Gene ◽  
Medical Procedures ◽  
Antibiotic Drugs ◽  
Genes Encoding ◽  
Infection Resistance ◽  
Invasive Medical Procedures

Staphylococcus aureus is the major pathogen causing nosocomial human infections and produces a variety of virulence factors that contribute to its ability to colonize and cause diseases. This study was conducted to investigate the virulence genes in S. aureus isolated from sterile body fluid samples and their correlation with clinical symptoms and outcomes. The VITEK 2® Compact system was used to perform biochemical identification and antimicrobial susceptibility tests on 33 S. aureus isolates. Virulence genes were amplified using multiplex PCR. The virulence gene patterns were analyzed by systematic cluster analysis. The frequency of methicillin-resistant S. aureus was 45.45%, and 17 virulence genes were identified. Genes encoding hemolysins showed high frequencies. The frequencies of hla, hlb, hld, and hlgB were 93.94% and that of the luk-F/S-PV was 21.21%. Except for the frequency of splB (51.52%), the remaining genes encoding invasive proteases showed frequencies greater than 81.82%. Among the patients, 100.00% had undergone invasive medical procedures and 24.00% had been treated with more than three types of antibiotic drugs. Invasive medical procedures are the main causes of infection. Resistance to antibiotic drugs and the status of carrying virulence genes were highly related to clinical symptoms and outcomes.

Virulence gene profiles inStaphylococcus aureusisolated from cows with subclinical mastitis in eastern Poland

2016 ◽  
Vol 83 (2) ◽  
pp. 228-235 ◽  
Author(s):  
Barbara Kot ◽  
Piotr Szweda ◽  
Aneta Frankowska-Maciejewska ◽  
Małgorzata Piechota ◽  
Katarzyna Wolska
Keyword(s):  
Staphylococcus Aureus ◽  
Serine Protease ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Virulence Gene ◽  
Subclinical Mastitis ◽  
Staph Aureus ◽  
Gene Profiles ◽  
Enterotoxin Genes ◽  
Genes Encoding

Staphylococcus aureusis arguably the most important pathogen involved in bovine mastitis. The aim of this study was to determine the virulence gene profiles of 124Staph. aureusisolates from subclinical mastitis in cows in eastern Poland. The presence of 30 virulence genes encoding adhesins, proteases and superantigenic toxins was investigated by PCR. The 17 different combinations of adhesin genes were identified. Occurrence ofeno(91·1%) andfib(82·3%) genes was found to be common. The frequency of other adhesion genesfnbA, fnbB, ebpswere 14·5, 50, 25%, respectively, and forcnaandbbpwere 1·6%. TheetAandetDgenes, encoding exfoliative toxins, were present in genomes of 5·6 and 8·9% isolates, respectively. ThesplAandsspA, encoding serine protease, were detected in above 90% isolates. The most frequent enterotoxin genes weresei(21%),sem(19·4%),sen(19·4%),seg(18·5%) andseo(13·7%). Thetstgene was harboured by 2·4% isolates. The 19 combinations of the superantigenic toxin genes were obtained and found in 35·5% of isolates. Three of them (seg, sei, sem, sen, seo; sec, seg, sei, sem, sen, seoandseg, sei, sem, sen) were the most frequent and found in 16·1% of the isolates. The most common virulotype, present in 17·7% of the isolates, wasfib, eno, fnbB, splA, splE, sspA. The results indicate the variation in the presence of virulence genes inStaph. aureusisolates and considerable diversity of isolates that are able to cause mastitis in cows.

scholarly journals Relationship between Vancomycin MIC and Virulence Gene Expression in Clonal Complexes of Methicillin-Susceptible Staphylococcus aureus Strains Isolated from Left-Sided Endocarditis

2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Juan M. Pericàs ◽  
Carlos Cervera ◽  
Cristina Garcia-de-la-Mària ◽  
Batu K. Sharma-Kuinkel ◽  
Rachelle Gonzales ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Multivariable Analysis ◽  
Virulence Gene ◽  
Mortality Rates ◽  
Content Type ◽  
Virulence Gene Expression ◽  
Vancomycin Mics ◽  
Genes Encoding

ABSTRACT Higher vancomycin MICs have been associated with more complicated courses and higher mortality rates in patients with Staphylococcus aureus bacteremia and infective endocarditis (IE). The aim of this study was to investigate whether the strains belonging to the cohort of 93 patients from a previously published study in which patients with strains with vancomycin MICs of ≥1.5 μg/ml presented higher mortality rates and systemic emboli than patients with strains with vancomycin MICs of <1.5 μg/ml had specific patterns of virulence factors, clonal complex (CC) types, or the ability to form biofilms. Vancomycin MICs were determined by Etest, and the isolates underwent spa typing to infer the CC, biofilm studies, a thrombin-induced platelet microbicidal assay, and multiplex PCR for the presence of virulence genes. We found no differences in genes encoding adhesins, toxins, or other putative virulence genes according to the vancomycin MIC group. CC30, CC34, and CC45 represented nearly half of the isolates, and there was no association with the vancomycin MIC. agr subgroups I and III predominated, with no association with the vancomycin MIC. Isolates with higher vancomycin MICs exhibited a poorer ability to form biofilms with and without the presence of vancomycin (2.03 versus 2.48 [P < 0.001], respectively, for isolates with higher vancomycin MICs and 2.60 versus 2.87 [P = 0.022], respectively, for isolates with lower vancomycin MICs). In the multivariable analysis, efb and V8 were risk factors for major emboli (adjusted odds ratio [aOR] = 7.5 and 95% confidence interval [CI] = 1.2 to 46.6 for efb, and aOR = 3.9 and 95% CI = 1.1 to 14.1 for V8), whereas no genotypic predictors of in-hospital mortality were found. No clear associations between genes encoding virulence factors, agr type, clonal complexes, mortality, and major embolic events according to vancomycin MIC group were found.

scholarly journals Distribution of virulence genes and SCCmec types among methicillin-resistant Staphylococcus aureus of clinical and environmental origin: a study from community of Assam, India

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Deepshikha Bhowmik ◽  
Shiela Chetri ◽  
Bhaskar Jyoti Das ◽  
Debadatta Dhar Chanda ◽  
Amitabha Bhattacharjee
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Genes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Virulence Gene ◽  
Type I ◽  
Methicillin Resistant ◽  
Type Iv ◽  
Clinical Community ◽  
Type V ◽  
Sccmec Types

Abstract Objective This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical, community and environmental settings. Results This study includes 1165 isolates collected from hospital, community and environmental settings. Among them sixty three were confirmed as MRSA with varied SCCmec types viz; type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII. The virulence gene such as sea (n = 54), seb (n = 21), eta (n = 27), etb (n = 2), cna (n = 24), ica (n = 2) and tst (n = 30) was also revealed from this study. The study underscores coexistence of resistance cassette and virulence genes among clinical and environment isolates which is first of its kind from this part of the world.

scholarly journals Molecular characteristics and virulence gene profiles of Staphylococcus aureus isolates in Hainan, China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Mainland China ◽  
Geographical Location ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Molecular Characteristics ◽  
Staphylococcal Protein A

Abstract Background There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus (S. aureus) from Hainan, the southernmost province of China. Methods Two hundred twenty-seven S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013–2014 and 2018–2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A (spa) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013 to 2014 (5.5%, 5/91) to 2018–2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCCmec) typing. SCCmec-IVa was the predominant SCCmec type, and specifically, ST45-SCCmec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S. aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin (pvl) and eta, were determined, and the frequency of eta and pvl were found to be 57.3 and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.

scholarly journals Distribution of Virulence Genes Among Methicillin-resistant Staphylococcus Aureus of Clinical and Environmental Origin

2020 ◽  
Author(s):  
Deepshikha Bhowmik ◽  
Shiela Chetri ◽  
Bhaskar Jyoti Das ◽  
Debadatta Dhar Chanda ◽  
Amitabha Bhattacharjee
Keyword(s):  
Staphylococcus Aureus ◽  
Multidrug Resistance ◽  
Virulence Genes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Virulence Gene ◽  
Type I ◽  
Type Ii ◽  
Methicillin Resistant ◽  
Type Iv ◽  
Type V

Abstract Objective: This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical and environmental settings. Results: The virulence gene such as sea (n=54), seb (n=21), eta (n=27), etb (n=2), cna (n=24), ica (n=2) and tst (n=30) was revealed from this study. Different SCCmec types such as type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII were detected among sixty three MRSA isolates where SCCmec type II having ST1551 and type V with ST2416 were found to be associated with multidrug resistance and were highly prevalent in the study area.

scholarly journals Staphylococcus aureus Pathogenicity in Cystic Fibrosis Patients—Results from an Observational Prospective Multicenter Study Concerning Virulence Genes, Phylogeny, and Gene Plasticity

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 279 ◽  
Author(s):  
Jonas Lange ◽  
Kathrin Heidenreich ◽  
Katharina Higelin ◽  
Kristina Dyck ◽  
Vanessa Marx ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Virulence Genes ◽  
Clinical Status ◽  
Virulence Gene ◽  
Clinical Deterioration ◽  
Limited Degree ◽  
Multi Center Study ◽  
The Impact ◽  
Specific Virulence

Staphylococcus aureus and cystic fibrosis (CF) are closely interlinked. To date, however, the impact of S. aureus culture in CF airways on lung function and disease progression has only been elucidated to a limited degree. This analysis aims to identify bacterial factors associated to clinical deterioration. Data were collected during an observational prospective multi-center study following 195 patients from 17 centers. The average follow-up time was 80 weeks. S. aureus isolates (n = 3180) were scanned for the presence of 25 virulence genes and agr-types using single and multiplex PCR. The presence of specific virulence genes was not associated to clinical deterioration. For the agr-types 1 and 4, however, a link to the subjects’ clinical status became evident. Furthermore, a significant longitudinal decrease in the virulence gene quantity was observed. Analyses of the plasticity of the virulence genes revealed significantly increased plasticity rates in the presence of environmental stress. The results suggest that the phylogenetic background defines S. aureus pathogenicity rather than specific virulence genes. The longitudinal loss of virulence genes most likely reflects the adaptation process directed towards a persistent and colonizing rather than infecting lifestyle.

scholarly journals Isolation and Characterization of Potentially Pathogenic Antimicrobial-Resistant Escherichia coli Strains from Chicken and Pig Farms in Spain

2010 ◽  
Vol 76 (9) ◽  
pp. 2799-2805 ◽  
Author(s):  
Pilar Cortés ◽  
Vanessa Blanc ◽  
Azucena Mora ◽  
Ghizlane Dahbi ◽  
Jesús E. Blanco ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Phylogenetic Analyses ◽  
Virulence Gene ◽  
E Coli ◽  
Isolation And Characterization ◽  
Zoonotic Risk ◽  
Poultry Farms ◽  
Pig Farms ◽  
Genes Encoding

ABSTRACT To ascertain whether on animal farms there reside extended-spectrum β-lactamase (ESBL) and plasmidic class C β-lactamase-producing Escherichia coli isolates potentially pathogenic for humans, phylogenetic analyses, pulsed-field gel electrophoresis (PFGE) typing, serotyping, and virulence genotyping were performed for 86 isolates from poultry (57 isolates) and pig (29 isolates) farms. E. coli isolates from poultry farms carried genes encoding enzymes of the CTX-M-9 group as well as CMY-2, whereas those from pig farms mainly carried genes encoding CTX-M-1 enzymes. Poultry and pig isolates differed significantly in their phylogenetic group assignments, with phylogroup A predominating in pig isolates and phylogroup D predominating in avian isolates. Among the 86 farm isolates, 23 (26.7%) carried two or more virulence genes typical of extraintestinal pathogenic E. coli (ExPEC). Of these, 20 were isolated from poultry farms and only 3 from pig farms. Ten of the 23 isolates belonged to the classic human ExPEC serotypes O2:H6, O2:HNM, O2:H7, O15:H1, and O25:H4. Despite the high diversity of serotypes and pulsotypes detected among the 86 farm isolates, 13 PFGE clusters were identified. Four of these clusters contained isolates with two or more virulence genes, and two clusters exhibited the classic human ExPEC serotypes O2:HNM (ST10) and O2:H6 (ST115). Although O2:HNM and O2:H6 isolates of human and animal origins differed with respect to their virulence genes and PFGE pulsotypes, the O2:HNM isolates from pigs showed the same sequence type (ST10) as those from humans. The single avian O15:H1 isolate was compared with human clinical isolates of this serotype. Although all were found to belong to phylogroup D and shared the same virulence gene profile, they differed in their sequence types (ST362-avian and ST393-human) and PFGE pulsotypes. Noteworthy was the detection, for the first time, in poultry farms of the clonal groups O25b:H4-ST131-B2, producing CTX-M-9, and O25a-ST648-D, producing CTX-M-32. The virulence genes and PFGE profiles of these two groups were very similar to those of clinical human isolates. While further studies are required to determine the true zoonotic potential of these clonal groups, our results emphasize the zoonotic risk posed especially by poultry farms, but also by pig farms, as reservoirs of ESBL- and CMY-2-encoding E. coli.

scholarly journals Molecular characteristics and virulence gene profiles of Staphylococcus aureus isolates in Hainan, China

2019 ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Mainland China ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Molecular Characteristics ◽  
Staphylococcal Protein A ◽  
Spa Typing

Abstract Background: There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus ( S. aureus ) from Hainan, the southernmost province of China. Methods: 227 S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013-2014 and 2018-2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results: Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A ( spa ) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013-2014 (5.5%, 5/91) to 2018-2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCC mec ) typing. SCC mec- IVa was the predominant SCC mec type, and specifically, ST45-SCC mec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S . aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin ( pvl ) and eta , were determined, and the frequency of eta and pvl were found to be 57.3% and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion: S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.

scholarly journals Molecular characteristics and virulence gene profiles of Staphylococcus aureus isolates in Hainan, China

2019 ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Mainland China ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Molecular Characteristics ◽  
Staphylococcal Protein A ◽  
Spa Typing

Abstract Background: There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus ( S. aureus ) from Hainan, the southernmost province of China. Methods: 227 S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013-2014 and 2018-2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results: Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A ( spa ) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013-2014 (5.5%, 5/91) to 2018-2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCC mec ) typing. SCC mec- IVa was the predominant SCC mec type, and specifically, ST45-SCC mec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S . aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin ( pvl ) and eta , were determined, and the frequency of eta and pvl were found to be 57.3% and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion: S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.

scholarly journals Bacteriocin activity of enterococci and presence of genes related to pathogenesis

2012 ◽  
Vol 30 (No. 4) ◽  
pp. 330-335 ◽  
Author(s):  
K. Trivedi ◽  
R. Sedmíková ◽  
R. Karpíšková
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Virulence Genes ◽  
Bacteriocin Production ◽  
Bacteriocin Activity ◽  
Antimicrobial Substances ◽  
Layer Technique ◽  
Genes Encoding ◽  
The Individual

In total 228 enterococci strains isolated from food were studied. Enterococcus faecalis, E. faecium, and E. casseliflavus were found to be the dominant strains while E. durans and E. mundtii were present in a smaller extent. Antimicrobial activity determined by double layer technique revealed that 150 (65.7%) strains showed antimicrobial activity against the individual tested pathogenic strains of Listeria monocytogenes, Staphylococcus aureus, and methicilin resistant S.&nbsp;aureus (MRSA). Cell-free neutralised supernatants (CFNS) were prepared from 150 potential bacteriocin producers. Of these 150, CFNS 107 (71.3%) strains were active in the bacteriocin production against one or more pathogenic strains tested. S. aureus and MRSA were found to be more sensitive to the antimicrobial substances than L. monocytogenes. Multiplex PCR for the detection of seven virulence genes in bacteriocin producing strains showed that 47.6% of strains were able to amplify one or more virulence genes. E. faecalis was the most virulent species. The presence of tyrdc gene was seen in all bacteriocin producing strains. None of the strains carried genes encoding the resistance to vancomycin. &nbsp;

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