Assessment of Vancomycin MIC Creep Phenomenon in Methicillin-Resistant Staphylococcus aureus isolates in a Tertiary Care Hospital of Lahore

  • Faiqa Arshad University of Health Sciences https://orcid.org/0000-0002-0738-3230
  • Sidrah Saleem University of Health Sciences, Lahore, Pakistan
  • Shah Jahan University of Health Sciences, Lahore, Pakistan
  • Romeeza Tahir University of Health Sciences, Lahore, Pakistan
Keywords: Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin intermediate Staphylococcus aureus (VISA), Vancomycin-resistant Staphylococcus aureus (VRSA), Minimum inhibitory concentration (MIC)

Abstract

Objective: To assess vancomycin MIC creep phenomenon in methicillin-resistant Staphylococcus aureus isolated from clinical specimens.

Methods: This descriptive study was conducted in Microbiology department of University of Health Sciences, Lahore from January 2016- December 2019. In this study, vancomycin MICs were revealed by E test method for clinical MRSA strains. For the final evaluation, a single isolate from each patient was taken. The reported vancomycin MICs results were used and the values were not rounded up to the next upward value. For every study year, MIC50, MIC90, median and geometrical mean MIC, percentages of susceptible and resistant strains were calculated.

Results: A total of 352 MRSA strains were isolated out of 2704 staphylococcal isolates. Our study showed elevated vancomycin MIC among MRSA isolates. The majority of isolates showed MIC values ≥1.5µg/ml. MIC50, MIC 90 was constant throughout four years period. However, geometric mean MIC increased gradually during the study period. The MIC greater than base year median was overall 17.3%. A complete shift can be observed between MIC “1.0” and “2.0” the percent of cases with MIC “1.0” decreased and with MIC “2.0” increased over time crossing each other in 2017.

Conclusion: Vancomycin MIC creep was identified in clinical isolates of MRSA, during four years of study period. Even though there is an absence of VISA and VRSA strains; this significant increase in vancomycin MIC trend is indeed worrying for the clinicians about the threat of potential failure of treatment in MRSA infections.

doi: https://doi.org/10.12669/pjms.36.7.3273

How to cite this:
Arshad F, Saleem S, Jahan S, Tahir R. Assessment of Vancomycin MIC Creep Phenomenon in Methicillin-Resistant Staphylococcus aureus isolates in a Tertiary Care Hospital of Lahore. Pak J Med Sci. 2020;36(7):1505-1510.   doi: https://doi.org/10.12669/pjms.36.7.3273

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Author Biographies

Faiqa Arshad, University of Health Sciences

Ph.D Scholar

Microbiology Department

University of Health Sciences, Lahore, Pakistan

Sidrah Saleem, University of Health Sciences, Lahore, Pakistan

Associate Professor & Head

Department of Microbiology

University of Health Sciences, Lahore, Pakistan

Shah Jahan, University of Health Sciences, Lahore, Pakistan

Assistant Professor

Department of Immunology

University of Health Sciences, Lahore, Pakistan.

Romeeza Tahir, University of Health Sciences, Lahore, Pakistan

Assistant Professor

Department of Immunology

University of Health Sciences, Lahore, pakistan

Published
2020-10-17
How to Cite
Arshad, F., Saleem, S., Jahan, S., & Tahir, R. (2020). Assessment of Vancomycin MIC Creep Phenomenon in Methicillin-Resistant Staphylococcus aureus isolates in a Tertiary Care Hospital of Lahore. Pakistan Journal of Medical Sciences, 36(7). https://doi.org/10.12669/pjms.36.7.3273
Section
Original Articles