Prevalence of macrolide-resistance genes in Staphylococcus aureus and Enterococcus faecium isolates from 24 European university hospitals

• Published in: Journal of antimicrobial chemotherapy 2000-06, Vol.45 (6), p.891-894
• Main Authors: Schmitz, Franz-Josef, Sadurski, Ralf, Kray, Angela, Boos, Mechthild, Geisel, Roland, Köhrer, Karl, Verhoef, Jan, Fluit, Ad C.
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Biological and medical sciences; Cross Infection - microbiology; DNA Primers; Drug Resistance, Microbial; Enterococcus faecium; Enterococcus faecium - drug effects; Enterococcus faecium - genetics; ereA gene; ereB gene; ermA gene; ermB gene; ermC gene; Erythromycin - pharmacology; Europe; Europe - epidemiology; Genes, Bacterial - genetics; Genome, Bacterial; Gram-Positive Bacterial Infections - epidemiology; Gram-Positive Bacterial Infections - microbiology; Hospitals, University; Humans; macrolide antibiotics; Medical sciences; msrA gene; msrB gene; Pharmacology. Drug treatments; Polymerase Chain Reaction; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococcus aureus; Staphylococcus aureus - drug effects; Staphylococcus aureus - genetics
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/45.6.891

The polymerase chain reaction (PCR) was used to study the prevalence of the macrolide resistance genes ermA, ermB, ermC, msrA/msrB, ereA and ereB, in 851 clinical isolates of Staphylococcus aureus and 75 clinical isolates of Enterococcus faecium that were erythromycin resistant. The isolates were from 24 European university hospitals. In S. aureus, the ermA gene was more common in methicillin-resistant S. aureus (MRSA) isolates (88%) than in methicillin-susceptible S. aureus (MSSA) isolates (38%), and occurred mainly in strains with constitutive MLSB expression. In contrast, ermC was more common in MSSA (47%) than in MRSA (5%), occurring mainly in strains with inducible expression. The ereB gene was only found in MRSA isolates expressing a constitutive MLSB phenotype (1%). The ereA gene was not detected. Macrolide resistance by efflux due to the msrA/msrB gene was only detected in MSSA isolates (13%). In contrast to S. aureus, erythromycin resistance in E. faecium was almost exclusively due to the presence of the ermB gene (93%).