|Year : 2015 | Volume
| Issue : 3 | Page : 455-456
Study of virulence factors in association with antimicrobial resistance amongst urinary isolates of enterococci
K Tiwari, T Banerjee, J Filgona, S Anupurba
Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
|Date of Submission||07-Feb-2014|
|Date of Acceptance||26-May-2014|
|Date of Web Publication||12-Jun-2015|
Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Tiwari K, Banerjee T, Filgona J, Anupurba S. Study of virulence factors in association with antimicrobial resistance amongst urinary isolates of enterococci. Indian J Med Microbiol 2015;33:455-6
|How to cite this URL:|
Tiwari K, Banerjee T, Filgona J, Anupurba S. Study of virulence factors in association with antimicrobial resistance amongst urinary isolates of enterococci. Indian J Med Microbiol [serial online] 2015 [cited 2019 Nov 12];33:455-6. Available from: http://www.ijmm.org/text.asp?2015/33/3/455/158602
Enterococci are increasingly being revealed as reservoirs of mobile genetic elements carrying resistance and virulence genes to other pathogens. We studied the prevalence of various virulence factors phenotypically and genotypically in association with drug resistance among the enterococcal isolates implicated in urinary tract infection (UTI).
One hundred biochemically confirmed isolates of enterococci were tested for antimicrobial susceptibility by Kirby Bauer disc diffusion test and respective screen agars for vancomycin (VRE) and high level gentamicin (HLGRE) as per standard.  Haemolysin and gelatinase production,  hemagglutination and biofilm formation  and presence of asa1 (aggregation substance), gelE (gelatinase), cylA (cytolysin), esp (enterococcal surface protein) and hyl (hyaluronidase) by multiplex polymerase chain reaction (PCR)  was studied. Presence of virulence factors and drug resistance was compared by Kruskal Wallis test and Mann U Whitney test (statistical package of social sciences, SPSS, version 15, Chicago, US).
Of the total, 46 isolates were E. faecalis and 54 E. faecium, of which 70% (32 E. faecalis and 38 E. faecium) were HLGRE and 7% (1 E. faecalis and 6 E. faecium) were VRE. Haemolysin and gelatinase production, haemagglutination and biofilm formation was seen in 29%, 17%, 39% 34%, respectively. Virulence factors were more in E. faecalis (P > 0.05). asa1 and gelE were the most prevalent virulence genes [Figure 1]. None harboured all the virulent genes and 10 isolates did not show any virulence factors. Majority of the strong biofilm producers possessed either asa1 or gelE gene. On statistical analysis, decreasing expression and possession of virulence genes was seen with increasing drug resistance (P < 0.05). Acquisition of vancomycin resistance resulted in this decrease (P < 0.05).
|Figure 1: Different virulent genes amongst the enterococcal isolates detected by multiplex PCR|
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We found that just as increase in one aspect of survival fitness reduces the other, as seen in community and hospital acquired Methicillin-resistant Staphylococcus aureus (MRSA),  acquisition of plasmids for drug resistance might have led to loss of virulence due to fitness cost benefits relating to VRE.
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