Bacteremia due to Staphylococcus aureus with reduced susceptibility to vancomycin

Samson Sai Yin Wong, Tak Keung Ng, Wing Cheong Yam, Dominic Ngai Chong Tsang, Patrick Chiu Yat Woo, Samuel Ka Shun Fung, Kwok Yung Yuen

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46 Citations (Scopus)

Abstract

Four cases of bacteremia caused by Staphylococcus aureus with heteroresistance to vancomycin (hetero-VRSA) were described. In at least two of these four mortalities, the cause of death was temporally related to the hetero-VRSA bacteremia. The vancomycin and teicoplanin MICs of the resistant subpopulations of these four hetero-VRSA were 8 and 24 μg/ml, respectively. All isolates were producers of β-lactamase, produced penicillin-binding protein PBP2a, and possessed the mecA gene accounting for methicillin resistance. Thickening of the peptidoglycan cell wall was observed by electron microscopy. When ampicillin was combined with vancomycin, in vitro synergism was detected using the checkerboard titration method (εFIC = 0.13). The use of vancomycin plus ampicillin-sulbactam could be a viable option in treating severe hetero-VRSA infection in view of the higher affinity of ampicillin toward PBP2a. Copyright (C) 2000 Elsevier Science Inc.

Original languageEnglish
Pages (from-to)261-268
Number of pages8
JournalDiagnostic Microbiology and Infectious Disease
Volume36
Issue number4
DOIs
Publication statusPublished - Apr 2000
Externally publishedYes

ASJC Scopus Subject Areas

  • Microbiology (medical)
  • Infectious Diseases

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