Distribution of Genes Encoding Resistance to Macrolides, Lincosamides and Streptogramins Among Clinical Staphylococcal Isolates in a Turkish University Hospital

Abstract

This study investigated the prevalence of genes encoding resistance to macrolides, lincosamides and streptogramins (MLS(B)) among staphylococci in a series of 301 erythromycin-resistant clinical isolates of Staphylococcus aureus and coagulase-negative staphylococci (CoNS). Erythromycin-resistance phenotypes were determined according to Clinical and Laboratory Standards Institute guidelines and specific resistance genes erm(A), erm(B), erm(C), msr(A) and msr(B) were identified using polymerase chain reaction. Two hundred of 301 (66.5%) erythromycin-resistant staphylococcal isolates exhibited resistance to MLS(B) antibiotics. Of these, 127 (63.5%) exhibited a cMLS(B) resistance phenotype (resistant to both erythromycin and clindamycin), whereas 73 (36.5%) expressed the iMLS(B) resistance phenotype (resistant to erythromycin and susceptible to clindamycin). The most prevalent resistance determinants were erm(A) (62%) among S. aureus and erm(C) (30%) among CoNS isolates. Combinations of resistance mechanisms were rarely seen, and occurred most often in oxacillin-resistant isolates. The results of the present study support the idea that there are geographical differences in the prevalence of erythromycin resistance mechanisms among staphylococci, therefore local surveillance studies are important tools for guiding therapy and in the promotion of judicious use of antimicrobial agents.

Molecular typing and characterization of macrolide, lincosamide and streptogramin resistance in Staphylococcus epidermidis strains isolated in a Mexican hospital

“…The ermA gene was the resistance determinant detected most frequently in S. epidermidis isolates, and similar results have been reported by other authors (Ardic et al, 2005). However, this result is in contrast to other findings, where the ermC gene was the main resistance determinant observed in CNS, including S. epidermidis (Lim et al, 2002;Cetin et al, 2010). In this study, only one isolate had the ermB gene, which has been detected by other groups in a low percentage of staphylococci (Hamilton-Miller & Shah, 2000;Chaieb et al, 2007).…”

Characterization of resistance genes to macrolides, lincosamides and streptogramins (MLS) among clinical isolates of Staphylococcus aureus in North Lebanon

“…Additionally, two isolates in our study harbored the linA gene. These results are also supported by recent findings, which showed that the linA gene was rarely detected in S. aureus strains [17,38,39].…”

Phenotypic and Genotypic Study of Inducible Clindamycin Resistance in Clinical Isolates of Staphylococcus aureus in Tabriz, Northwest Iran

“…Our finding did not show any msrA gene that is similar to the two available studies from Iran (17,33). However, different low rates of msrA gene have been reported by other researchers (16,38,40).…”

“…Based on the findings of our study and some other studies, no ermB gene has been found in studied isolates of S. aureus (17,33,38). But in 3 studies conducted in France, Brazil, and Turkey, the frequency of ermB gene was 0.7%, 2.2%, and 8.3%, respectively (16,39,40).…”