Prevalence of vancomycin-resistant enterococci from three tertiary care hospitals and role of esp gene in biofilm formation

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Prevalence of vancomycin-resistant enterococci from three tertiary care hospitals and role of esp gene in biofilm formation

Mutiullah Khattak, Sabir Nawaz, Neak Muhammad, Asif Jamal, Sohail Akhtar, Rubina Kamran, Naeem Akhtar, Fariha Hasan, Aamer Ali Shah
Int. J. Biosci.10( 3), 24-34, March 2017.
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The purpose of this study was to elucidate antibiotic resistance profile of 143 Enterococcus spp. isolates against vancomycin and other antimicrobial agents from three Pakistani hospitals and to show a relationship between biofilm formation and esp gene as virulence factors. Different specimens, mainly, urine, blood and pus were processed for this purpose. Antibiotic resistance profile was elucidated through Kirby-Bauer disc diffusion and E-test methods. Isolates were screened for biofilm formation using microtiter plate method and the presence of esp gene was determined through Polymerase Chain Reaction (PCR). A Chi-square ( ) test was used to find association between biofilm formation and the presence of esp gene. Among 143 isolates, 25 (17.48%) were found to be Vancomycin-Resistant Enterococci (VRE). The resistance against linezolid was very low, i.e., only 01 isolate was resistant and 07 intermediately resistant. None of the isolates were found resistant to tigecycline. Among VRE, 90.5% Enterococcus faecium and 100% Enterococcus faecalis isolates were positive for biofilm formation. The association between biofilm formation and esp gene was found insignificant (p-value >0.05) for both vancomycin-resistant and sensitive isolates. The frequency of vancomycin resistance in Enterococcus spp. is gradually increasing in Pakistan. Beyond vancomycin, tigecycline, linezolid and teicoplanin were the most effective antimicrobial agents in a local hospital setting. Biofilm was formed in most of the isolates, which might cause nosocomial infections, regardless of the presence of esp gene.


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