A Study of Prevalance of Vancomycin Resistance among the Enterococcus Spp. Isolated from Various Clinical Smaples in a Tertiary Care Hospital in Chennai.

Nalayini, S (2013) A Study of Prevalance of Vancomycin Resistance among the Enterococcus Spp. Isolated from Various Clinical Smaples in a Tertiary Care Hospital in Chennai. Masters thesis, Stanley Medical College, Chennai.


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INTRODUCTION : The Enterococci are normal commensal microorganisms , considered virtually as harmless bacteria. Normally it is a part of the indigenous flora of the intestinal tract, oral cavity and genitourinary tract of humans and animals. They have long been known as` Faecal Streptococci’ , a potential human pathogen, capable of causing a variety of infections in the community as well as in the hospital. During the past few decades , they have emerged as an important nosocomial pathogen exhibiting multiple drug resistance, contributing significantly to patient morbidity and mortality. It is due to their ability to survive and disseminate in hospital environment which is mainly attributed to their intrinsic resistance to many of the commonly used antibiotics and especially to their ability to acquire resistance to most of the currently available antibiotics either by mutation or through transfer of mobile genetic elements carrying resistance genes/ virulence factors. AIMS : To study the prevalence of vancomycin resistance among the Enterococcal species isolated from various clinical samples such as urine, blood, pus, tissue fluids and feces obtained from the patients of a tertiary care hospital. OBJECTIVES : 1. Isolation and identification of Enterococci from various clinical samples by standard techniques. 2. Characterization of the Enterococcal isolates to the species level. 3. Assessment of the Antibiotic susceptibility pattern of these isolates by standard techniques. 4. To study the specific resistance mechanisms like resistance to penicillins, High level Aminoglycoside resistance (HLAR) by standard techniques. 5. To study the vancomycin resistance among the Enterococcal isolates and its characterization by standard phenotypic methods. 6. To assess the prevalence of VanA genotype among the Vancomycin Resistant Enterococci by Polymease Chain Reaction (PCR)assay for VanA gene. CONCLUSION : Enterococci are emerging as an important pathogen causing variety of hospital acquired nosocomial infections and also cause community acquired infections contributing significantly to patients morbidity and mortality. The emergence of vancomycin resistant Enterococci worsens the problem further because of the multidrug resistance exhibited by these agents leaving fewer therapeutic options for the clinicians in treating the serious life threatening VRE infections. In our study we isolated a total of 240 Enterococcal isolates from various clinical samples with Enterococcus faecalis and Enterococcus faecium as the predominant species . Of these 21 isolates were identified as Vancomycin Resistant Enterococci with a prevalence rate of about 8.7% as per Vancomycin MIC and the prevalence of VanA genotype VRE is 4.1% by PCR assay in this region. They showed resistance to multiple antibiotics like penicillin, ampicillin, doxycycline and exhibited higher rate of high level aminoglycoside resistance. The Enteroccocal isolates presumptively identified by vancomycin screen agar should be confirmed by determining the minimum inhibitory concentration for vancomycin. The phenotyping of VRE isolates performed by detection of MIC for both vancomycin and teicoplanin correlates well with the genotypic method of detection of vancomycin resitance geneVanA. Thus this method can be adopted in resource limited settings (where the genotyping may not be available) for the detection of Vancomycin resistant phenotype of Enterococci. This emphasizes the need for conducting frequent surveillance programmes for prompt identification of VRE in hospitals and community. This also emphasizes the need for implementation of stringent infection control measures like rational use of antibiotics especially restricting the use of Vancomycin to minimum, proper containment and effective treatment of VRE infections, strict hand washing practices, education of the healthcare workers and other personnel involved in the patient management. These measures are to be strictly followed to bring down the mortality and morbidity associated with these nosocomial VRE infections.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Vancomycin Resistance ; Prevalance ; Enterococcus Spp ; Clinical Smaples ; Tertiary Care Hospital ; Chennai.
Subjects: MEDICAL > Microbiology
Depositing User: Subramani R
Date Deposited: 24 Jul 2017 05:04
Last Modified: 24 Jul 2017 05:04
URI: http://repository-tnmgrmu.ac.in/id/eprint/1676

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