Comparative evaluation of MIC of Vancomycin among methicillin resistant Staphylococcus aureus (MRSA) isolates in tertiary care hospital

Authors

  • Swarupa Rani
  • Tejashree.A
  • Ranjitha Shankare Gowda
  • Krishna Karthik M.V.S
  • Eeshita Dhar
  • B. Satya Sai

DOI:

https://doi.org/10.37506/ijphrd.v14i4.18635

Keywords:

Staphylococcus aureus, MIC (minimum inhibitory concentration), MRSA (methicillin resistant Staphylococcus aureus), VSSA (Vancomycin susceptible Staphylococcus aureus).

Abstract

Vancomycin, a glycopeptide antibiotic with in-vitro activity against all staphylococci and clinical response to methicillin
resistant staphylococcus aureus (MRSA) infection, became the backbone of treatment due to MRSA’s universal
resistance to the antimicrobial agents belonging to beta-lactams and There are no other viable options. In patients with
staphylococcal infections, this study demonstrated a significant conflict of minimum inhibitory concentrations (MICs) of
vancomycin for MRSA strains between an automated system, Vitek 2, and the method. test E-strip. In the Microbiology
laboratory of JSS hospital which is a tertiary care center situated in Mysuru, 90 isolates were acquired from various
clinical samples to analyse Vancomycin MIC. Out of 90 isolates, 2.2% MRSA isolates showed highest vancomycin MIC
2μg/ml by Vitek-2 method, where no isolates showed MIC up-to 2μg/ml by E-strip method. But the higher vancomycin
MIC 1μg/ml was observed in 82.2% by vancomycin E-strip method compared to 37.7% by Vitek-2 method. Lowest MIC
0.5μg/ml showed by Vitek-2 method in 58.8% compared to 4.4% by E-strip method. The study concludes that all S. aureus
isolates were resistant to methicillin by both Vitek-2 system and cefoxitin disc diffusion method and also identified as
VSSA (vancomycin susceptible Staphylococcus aureus) by Vitek-2 and E-test method. Higher vancomycin MIC ≥1μg/ml
in 93.3% may be due to using of vancomycin improperly and infrequently in MRSA infection with lowest MIC value.
Therefore, this method can also be used as routine laboratory practice or as alternative method where Vitek 2 system or
other methods are not available.

Author Biographies

Swarupa Rani

M.Sc Post graduate, Dept of Microbiology, JSSMC, JSSAHER, Mysore

Tejashree.A

Prof & HOD, Dept of Microbiology, JSSMC, JSSAHER, Mysore

Ranjitha Shankare Gowda

Assistant Professor, Dept of Microbiology, JSSMC, JSSAHER, Mysore

Krishna Karthik M.V.S

Tutor, Dept of Microbiology, JSSMC, JSSAHER, Mysore

Eeshita Dhar

PhD Research Scholar, Dept of Microbiology, JSSMC, JSSAHER, Mysore

B. Satya Sai

Tutor, Dept of Microbiology, JSSMC, JSSAHER, Mysore

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Published

2022-10-10

How to Cite

Swarupa Rani, Tejashree.A, Ranjitha Shankare Gowda, Krishna Karthik M.V.S, Eeshita Dhar, & B. Satya Sai. (2022). Comparative evaluation of MIC of Vancomycin among methicillin resistant Staphylococcus aureus (MRSA) isolates in tertiary care hospital. Indian Journal of Public Health Research & Development, 13(4), 308–312. https://doi.org/10.37506/ijphrd.v14i4.18635