Low-Level Vancomycin Resistance in Clostridium innocuum

Low-level vancomycin resistance in Clostridium innocuum.

Low-level vancomycin resistance was observed for 28 clinical Clostridium innocuum isolates and C. innocuum NCIB 10674, whereas teicoplanin was active. DNA from three clinical isolates and the type strain could not be amplified by PCR with primers specific for the genes vanA, vanB, and vanC, suggesting that C. innocuum is intrinsically resistant to vancomycin.

Identification of Low-Level Vancomycin Resistance in Staphylococcus aureus in the Era of Informatics.

Vancomycin-intermediateStaphylococcus aureus(VISA) and heteroresistant VISA (hVISA) are pathogens for which accurate antimicrobial susceptibility testing (AST) would rule out standard treatment with vancomycin. Unfortunately, AST for vancomycin is relatively slow and standard methods are unable to reliably detect VISA and hVISA. An article in this issue (C. A. Mather, B. J. Werth, S. Sivagnanam...

Vancomycin Resistance in Staphylococcus aureus Strains

High-Level Fosfomycin Resistance in Vancomycin-Resistant Enterococcus faecium

Of 890 vancomycin-resistant Enterococcus faecium isolates obtained by rectal screening from patients in Pittsburgh, Pennsylvania, USA, 4 had MICs >1,024 μg/mL for fosfomycin. These isolates had a Cys119Asp substitution in the active site of UDP-N-acetylglucosamine enolpyruvyl transferase. This substitution increased the fosfomycin MIC >4-fold and rendered this drug inactive in biochemical assays.

Isolates with low-level vancomycin resistance associated with persistent methicillin-resistant Staphylococcus aureus bacteremia.

Low-level vancomycin-resistant Staphylococcus aureus (vancomycin-intermediate S. aureus [VISA] and heterogenous VISA [hVISA]) is increasingly reported and leads to glycopeptide treatment failure. Various phenotypic features have been reported for these isolates, but the genetic changes leading to hVISA and VISA have yet to be clearly determined. We assessed phenotypic, antibiotic resistance, an...