<abstract xmlns="http://www.w3.org/1999/xhtml"><p> The clinical relevance of Staphylococcus aureus strains with heterointermediate susceptibility to vancomycin (hVISA) is still controversial, however they could be responsible for treatment failures in patients treated with vancomycin. The lack of standardization and the complexity of testing methods are the main challenge in indentifying such strains. The aim of our study was to evaluate the frequency of hVISA strains in Targu-Mures Clinical Emergency Hospital. One hundred twenty-two, non-duplicate, methicillin-resistant S. aureus (MRSA) isolates susceptible to vancomycin using standard E-test (MIC≤2 mg/L) were screened for heteroresistance with Glycopeptide Resistance Detection test (E-test GRD). Population analysis profile-area under the curve (PAP/AUC) method was used for confirmation. Twenty-four strains (19.5%) were found positive with the screening method. Two of them (1.63%) were confirmed having hVISA phenotype and no strains with intermediate vancomycin susceptibility (VISA) were detected. In conclusion, the rate of MRSA strains with reduced vancomycin susceptibility was low. However, their monitoring may be useful, taking into consideration the wide usage of glycopeptides in the treatment of serious MRSA infections.</p></abstract>

The clinical relevance of Staphylococcus aureus strains with heterointermediate susceptibility to vancomycin (hVISA) is still controversial, however they could be responsible for treatment failures in patients treated with vancomycin. The lack of standardization and the complexity of testing methods are the main challenge in indentifying such strains. The aim of our study was to evaluate the frequency of hVISA strains in Targu-Mures Clinical Emergency Hospital. One hundred twenty-two, non-duplicate, methicillin-resistant S. aureus (MRSA) isolates susceptible to vancomycin using standard E-test (MIC≤2 mg/L) were screened for heteroresistance with Glycopeptide Resistance Detection test (E-test GRD). Population analysis profile-area under the curve (PAP/AUC) method was used for confirmation. Twenty-four strains (19.5%) were found positive with the screening method. Two of them (1.63%) were confirmed having hVISA phenotype and no strains with intermediate vancomycin susceptibility (VISA) were detected. In conclusion, the rate of MRSA strains with reduced vancomycin susceptibility was low. However, their monitoring may be useful, taking into consideration the wide usage of glycopeptides in the treatment of serious MRSA infections.

Study of Decreased Susceptibility to Vancomycin in Methicillin-Resistant Staphylococcus aureus Strains isolated from a Romanian Multidisciplinary Emergency Hospital

University of Medicine and Pharmacy, Tîrgu Mureş, Microbiology Department

Revista Romana de Medicina de Laborator

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

The clinical relevance of Staphylococcus aureus strains with heterointermediate susceptibility to vancomycin (hVISA) is still controversial, however they could...

Study of Decreased Susceptibility to Vancomycin in Methicillin-Resistant Staphylococcus aureus Strains isolated from a Romanian Multidisciplinary Emergency Hospital

Published Online: Jun 21, 2014

Page range: 245 - 254

Received: Dec 31, 2013

Accepted: Apr 08, 2014

DOI: https://doi.org/10.2478/rrlm-2014-0013

Keywords
hVISA screening;glycopeptide resistance detection;population analysis

© by Krisztina Eszter Vas

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Study of Decreased Susceptibility to Vancomycin in Methicillin-Resistant Staphylococcus aureus Strains isolated from a Romanian Multidisciplinary Emergency Hospital

Published Online: Jun 21, 2014

Page range: 245 - 254

Received: Dec 31, 2013

Accepted: Apr 08, 2014

DOI: https://doi.org/10.2478/rrlm-2014-0013

KeywordshVISA screening;glycopeptide resistance detection;population analysis

© by Krisztina Eszter Vas

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Keywords
hVISA screening;glycopeptide resistance detection;population analysis