scholarly journals Antibiotic-resistance and virulence genes in Enterococcus isolated from tropical recreational waters

2013 ◽  
Vol 11 (3) ◽  
pp. 387-396 ◽  
Author(s):  
Tasha M. Santiago-Rodriguez ◽  
Jessica I. Rivera ◽  
Mariel Coradin ◽  
Gary A. Toranzos

The prevalence of enterococci harboring tetracycline- and vancomycin-resistance genes, as well as the enterococcal surface protein (esp) has mostly been determined in clinical settings, but their prevalence in tropical recreational waters remains largely unknown. The present study determined the prevalence of tetM (tetracycline-resistance), vanA and vanB (vancomycin-resistance) in the bacterial and viral fractions, enterococci and their induced phages isolated from tropical recreational marine and fresh waters, dry and wet sands. Since lysogenic phages can act as vectors for antibiotic-resistance and virulence factors, the prevalence of the mentioned genes, as well as that of an integrase-encoding gene (int) specific for Enterococcus faecalis phages was determined. Up to 60 and 54% of the bacterial fractions and enterococci, respectively, harbored at least one of the tested genes suggesting that bacteria in tropical environments may be reservoirs of antibiotic-resistance and virulence genes. int was detected in the viral fractions and in one Enterococcus isolate after induction. This study presents the opportunity to determine if the presence of bacteria harboring antibiotic-resistance and virulence genes in tropical recreational waters represents a threat to public health.

2006 ◽  
Vol 72 (6) ◽  
pp. 4028-4035 ◽  
Author(s):  
Lilia Macovei ◽  
Ludek Zurek

ABSTRACT In this project, enterococci from the digestive tracts of 260 houseflies (Musca domestica L.) collected from five restaurants were characterized. Houseflies frequently (97% of the flies were positive) carried enterococci (mean, 3.1 � 103 CFU/fly). Using multiplex PCR, 205 of 355 randomly selected enterococcal isolates were identified and characterized. The majority of these isolates were Enterococcus faecalis (88.2%); in addition, 6.8% were E. faecium, and 4.9% were E. casseliflavus. E. faecalis isolates were phenotypically resistant to tetracycline (66.3%), erythromycin (23.8%), streptomycin (11.6%), ciprofloxacin (9.9%), and kanamycin (8.3%). Tetracycline resistance in E. faecalis was encoded by tet(M) (65.8%), tet(O) (1.7%), and tet(W) (0.8%). The majority (78.3%) of the erythromycin-resistant E. faecalis isolates carried erm(B). The conjugative transposon Tn916 and members of the Tn916/Tn1545 family were detected in 30.2% and 34.6% of the identified isolates, respectively. E. faecalis carried virulence genes, including a gelatinase gene (gelE; 70.7%), an aggregation substance gene (asa1; 33.2%), an enterococcus surface protein gene (esp; 8.8%), and a cytolysin gene (cylA; 8.8%). Phenotypic assays showed that 91.4% of the isolates with the gelE gene were gelatinolytic and that 46.7% of the isolates with the asa1 gene aggregated. All isolates with the cylA gene were hemolytic on human blood. This study showed that houseflies in food-handling and -serving facilities carry antibiotic-resistant and potentially virulent enterococci that have the capacity for horizontal transfer of antibiotic resistance genes to other bacteria.


2010 ◽  
Vol 77 (1) ◽  
pp. 327-329 ◽  
Author(s):  
Robert W. Phelan ◽  
Charles Clarke ◽  
John P. Morrissey ◽  
Alan D. W. Dobson ◽  
Fergal O'Gara ◽  
...  

ABSTRACTKnowledge of the nature of resistance determinants in natural habitats is fundamental to increasing our understanding of the development of antibiotic resistance in clinical settings. Here we provide the first report of a tetracycline resistance-encoding plasmid, pBHS24, from a marine sponge-associated bacterium,Bacillussp. strain #24, isolated fromHaliclona simulans.


2007 ◽  
Vol 70 (6) ◽  
pp. 1316-1327 ◽  
Author(s):  
FATOUMATA DIARRASSOUBA ◽  
MOUSSA SORY DIARRA ◽  
SUSAN BACH ◽  
PASCAL DELAQUIS ◽  
JANE PRITCHARD ◽  
...  

Antibiotic resistance patterns and the presence of antibiotic and virulence determinants in 74 sorbitol-negative Escherichia coli and 62 Salmonella isolates from nine different broiler chicken farms were investigated. Each farm was supplied by one of three companies that used different antimicrobial agents in feed for growth promotion. The isolates were identified by API 20E for E. coli and by serological tests for Salmonella. The susceptibility of the isolates to antibiotics was determined by Sensititre using the Clinical and Laboratory Standards Institute's breakpoints. Fifty-two E. coli isolates (70.3%) and nine Salmonella isolates (14.52%) were multiresistant to at least nine antibiotics. The multiresistant isolates were evaluated for the presence of tetracycline resistance, integron class 1, and blaCMY-2 genes by PCR. Of the 74 E. coli isolates, 55 were resistant to amoxicillin and ceftiofur. Among these 55 resistant E. coli isolates, 45 (81.8%) and 22 (40.0%) were positive for blaCMY-2 and qacEΔ1-SulI genes, respectively. Tetracycline resistance was found in 56 isolates (75.8%) among which 12 (21.4%) and 24 (42.9%) gave positive results for tetA and tetB, respectively. Virulence genes (iss, tsh, and traT ), aerobactin operon (iucC), and the eaeA gene were detected in some E. coli strains. Among the 27 amoxicillin- and ceftiofur-resistant Salmonella isolates, the blaCMY-2 gene was detected in 22 isolates. The class 1 integron gene (qacEΔ1-SulI) was not detected in any Salmonella isolates, whereas the invasin (inv) and virulence (spv) genes were found in 61 (98.4%) and 26 (42%) of the Salmonella isolates, respectively. This study indicated that multiple antibiotic-resistant commensal E. coli and Salmonella strains carrying virulence genes can be found on commercial broiler chicken farms and may provide a reservoir for these genes in chicken production facilities. Except for the presence of tetB, there was no significant effect of feed formulations on the phenotypic or genotypic characteristics of the isolates.


2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Karthika Suryaletha ◽  
Lekshmi Narendrakumar ◽  
Joby John ◽  
Dinesh Reghunathan ◽  
Manoj Prasannakumar ◽  
...  

ABSTRACT Enterococcus faecalis is recognized as one of the leading pathogens causing nosocomial infections. Here we report a draft genome sequence of Enterococcus faecalis SK460, isolated from a chronic diabetic foot ulcer patient. This strain exhibits various biofilm-associated genes, virulence genes, and antibiotic-resistance genes related to aminoglycoside, macrolide, and tetracycline resistance.


2019 ◽  
Vol 87 (4) ◽  
pp. 195-203
Author(s):  
Anna Sieńko ◽  
Sławomir Czaban ◽  
Dominika Ojdana ◽  
Piotr Majewski ◽  
Anna Wieczorek ◽  
...  

Aim. Today, infections caused by vancomycin-resistant Enterococcus faecium (VRE) are a major problem in the healthcare system. The aim of this study was to compare the antibiotic resistance and virulence traits between vancomycin-susceptible E. faecium (VSE) and VRE clinical isolates.Material and Methods. Studies were performed on 66 E. faecium (32 VRE and 34 VSE) strains. Susceptibility testing and identification were performed, and strains were examined for ß-lactamase, hemolysin and biofilm production. Isolates were tested for the presence of 5 van genes, 8 virulence genes and 6 aminoglycoside-modifying enzyme (AME) genes. Obtained amplicons were subjected to electrophoretical separation and DNA sequencing.Results. Among 32 VRE isolates, 28 were found to have the VanA phenotype, and 4 the VanB. The most frequent resistance and virulence profile among VRE strains was resistance to ampicillin, imipenem, gentamicin, streptomycin, teicoplanin, and vancomycin with enterococcal surface protein (esp), endocarditis antigen (efaA), collagen adhesin (acm), and hialuronidase (hyl) genes; among VSE: resistance to ampicillin, imipenem, gentamicin, streptomycin with esp, efaA, acm, and hyl genes. Conclusions. Our findings prove that both VRE and VSE strains were well equipped with virulence and resistance genes, although VRE strains were characterized by a greater variety and a higher number of these genes. However, statistical analysis revealed no significant differences between VSE and VRE strains (p > 0.05). Nevertheless, our results suggest that VRE strains may slowly acquire and incorporate resistance and virulence genes, due to their ability to survive in a hospital environment for a long time.


2021 ◽  
Vol 9 (4) ◽  
pp. 789
Author(s):  
Michael Conwell ◽  
James S. G. Dooley ◽  
Patrick J. Naughton

Enterococci and biofilm-associated infections are a growing problem worldwide, given the rise in antibiotic resistance in environmental and clinical settings. The increasing incidence of antibiotic resistance and its propagation potential within enterococcal biofilm is a concern. This requires a deeper understanding of how enterococcal biofilm develops, and how antibiotic resistance transfer takes place in these biofilms. Enterococcal biofilm assays, incorporating the study of antibiotic resistance transfer, require a system which can accommodate non-destructive, real-time experimentation. We adapted a Gene Frame® combined with fluorescence microscopy as a novel non-destructive platform to study the conjugal transfer of vancomycin resistance in an established enterococcal biofilm.A multi-purpose fluorescent in situ hybridisation (FISH) probe, in a novel application, allowed the identification of low copy number mobile elements in the biofilm. Furthermore, a Hoechst stain and ENU 1470 FISH probe identified Enterococcus faecium transconjugants by excluding Enterococcus faecalis MF06036 donors. Biofilm created with a rifampicin resistant E. faecalis (MW01105Rif) recipient had a transfer efficiency of 2.01 × 10−3; double that of the biofilm primarily created by the donor (E. faecalis MF06036). Conjugation in the mixed enterococcal biofilm was triple the efficiency of donor biofilm. Double antibiotic treatment plus lysozyme combined with live/dead imaging provided fluorescent micrographs identifying de novo enterococcal vancomycin resistant transconjugants inside the biofilm. This is a model system for the further study of antibiotic resistance transfer events in enterococci. Biofilms promote the survival of enterococci and reduce the effectiveness of drug treatment in clinical settings, hence giving enterococci an advantage. Enterococci growing in biofilms exchange traits by means of horizontal gene transfer, but currently available models make study difficult. This work goes some way to providing a non-destructive, molecular imaging-based model system for the detection of antibiotic resistance gene transfer in enterococci.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li

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.


2007 ◽  
Vol 73 (21) ◽  
pp. 6740-6747 ◽  
Author(s):  
Lilia Macovei ◽  
Ludek Zurek

ABSTRACT The influx of enterococcal antibiotic resistance (AR) and virulence genes from ready-to-eat food (RTEF) to the human digestive tract was assessed. Three RTEFs (chicken salad, chicken burger, and carrot cake) were sampled from five fast-food restaurants five times in summer (SU) and winter (WI). The prevalence of enterococci was significantly higher in SU (92.0% of salad samples and 64.0% of burger samples) than in WI (64.0% of salad samples and 24.0% of burger samples). The overall concentrations of enterococci during the two seasons were similar (∼103 CFU/g); the most prevalent were Enterococcus casseliflavus (41.5% of isolates) and Enterococcus hirae (41.5%) in WI and Enterococcus faecium (36.8%), E. casseliflavus (27.6%), and Enterococcus faecalis (22.4%) in SU. Resistance in WI was detected primarily to tetracycline (50.8%), ciprofloxacin (13.8%), and erythromycin (4.6%). SU isolates were resistant mainly to tetracycline (22.8%), erythromycin (22.1%), and kanamycin (13.0%). The most common tet gene was tet(M) (35.4% of WI isolates and 11.9% of SU isolates). The prevalence of virulence genes (gelE, asa1, cylA, and esp) and marker genes for clinical isolates (EF_0573, EF_0592, EF_0605, EF_1420, EF_2144, and pathogenicity island EF_0050) was low (≤12.3%). Genotyping of E. faecalis and E. faecium using pulsed-field gel electrophoresis revealed that the food contamination likely originated from various sources and that it was not clonal. Our conservative estimate (single AR gene copy per cell) for the influx of tet genes alone to the human digestive tract is 3.8 � 105 per meal (chicken salad). This AR gene influx is frequent because RTEFs are commonly consumed and that may play a role in the acquisition of AR determinants in the human digestive tract.


2016 ◽  
Vol 47 (4) ◽  
pp. 306-311 ◽  
Author(s):  
Safoura Derakhshan ◽  
Shahin Najar Peerayeh ◽  
Bita Bakhshi

2016 ◽  
Vol 15 (2) ◽  
pp. 196-208 ◽  
Author(s):  
Nicole M. Masters ◽  
Aaron Wiegand ◽  
Jasmin M. Thompson ◽  
Tara L. Vollmerhausen ◽  
Eva Hatje ◽  
...  

We investigated Escherichia coli populations in a metropolitan river after an extreme flood event. Between nine and 15 of the 23 selected sites along the river were sampled fortnightly over three rounds. In all, 307 E. coli were typed using the PhP typing method and were grouped into common (C) or single (S) biochemical phenotypes (BPTs). A representative from each of the 31 identified C-BPTs was tested for 58 virulence genes (VGs) associated with intestinal and extra-intestinal E. coli, resistance to 22 antibiotics, production of biofilm and cytotoxicity to Vero cells. The number of E. coli in the first sampling round was significantly (P < 0.01) higher than subsequent rounds, whereas the number of VGs was significantly (P < 0.05) higher in isolates from the last sampling round when compared to previous rounds. Comparison of the C-BPTs with an existing database from wastewater treatment plants (WWTPs) in the same catchment showed that 40.6% of the river isolates were identical to the WWTP isolates. The relatively high number of VGs and antibiotic resistance among the C-BPTs suggests possessing and retaining these genes may provide niche advantages for those naturalised and/or persistent E. coli populations which may pose a health risk to the community.


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