Meticillin-resistant Staphylococcus aureus with a novel mecA homologue in human and bovine populations in the UK and Denmark: a descriptive study.

Background: Animals can act as a reservoir and source for the emergence of novel meticillin-resistant Staphylococcus aureus (MRSA) clones in human beings. Here, we report the discovery of a strain of S aureus (LGA251) isolated from bulk milk that was phenotypically resistant to meticillin but tested negative for the mecA gene and a preliminary investigation of the extent to which such strains are present in bovine and human populations.

Methods: Isolates of bovine MRSA were obtained from the Veterinary Laboratories Agency in the UK, and isolates of human MRSA were obtained from diagnostic or reference laboratories (two in the UK and one in Denmark).

Evaluation of selective and enrichment media for isolation of glycopeptide-resistant enterococci from faecal specimens.

Objectives: Vancomycin-resistant enterococcus enrichment broth (VEB) and vancomycin-resistant enterococcus selective agar with vancomycin 6 mg/L (VSA) are novel azide-aesculin agar-based media that contain meropenem as an additional selective agent. The media were compared with enterococcosel broth (EB) and enterococcosel agar with vancomycin 6 mg/L (EA) for the isolation of glycopeptide-resistant enterococci (GRE) from routine faecal screening specimens.

Methods: Two hundred and eighteen routine faecal screening specimens from patients at Addenbrooke's Hospital were examined.