The prevalence of genotypes that determine resistance to macrolides, lincosamides, and streptogramins B compared with spiramycin susceptibility among erythromycin-resistant Staphylococcus epidermidis

Abstract

Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, can be regarded as potential reservoirs of resistance genes for pathogenic strains, e.g., Staphylococcus aureus. The aim of this study was to assess the prevalence of different resistance phenotypes to macrolide, lincosamide, and streptogramins B (MLSB) antibiotics among erythromycin-resistant S. epidermidis, together with the evaluation of genes promoting the following different types of MLSB resistance:ermA, ermB, ermC,msrA, mphC, and linA/A’. Susceptibility to spiramycin was also examined. Among 75 erythromycin-resistantS. epidermidis isolates, the most frequent phenotypes were macrolides and streptogramins B (MSB) and constitutive MLSB (cMLSB). Moreover, all strains with the cMLSB phenotype and the majority of inducible MLSB (iMLSB) isolates were resistant to spiramycin, whereas strains with the MSB phenotype were sensitive to this antibiotic. The D-shape zone of inhibition around the clindamycin disc near the spiramycin disc was found for some spiramycin-resistant strains with the iMLSB phenotype, suggesting an induction of resistance to clindamycin by this 16-membered macrolide. The most frequently isolated gene was ermC, irrespective of the MLSB resistance phenotype, whereas the most often noted gene combination wasermC, mphC, linA/A’. The results obtained showed that the genes responsible for different mechanisms of MLSB resistance in S. epidermidis generally coexist, often without the phenotypic expression of each of them.

Prevalence of Genotypes That Determine Resistance of Staphylococci to Macrolides and Lincosamides in Serbia

“…The erm C gene was the most common among all erm genes in both S. aureus and CNS exhibiting cMLSb or iMLSb phenotype. Similar data were reported by Juda et al ( 23 ). In Brazil, Coutinho et al ( 24 ) reported low frequency of the erm B gene, data which did not differ from our study.…”

Skin microbiome and acne vulgaris: Staphylococcus, a new actor in acne

“…The study demonstrated that erythromycin reduced the number of Actinobacteria (including Corynebacterium and Propionibacterium ) while it only had a limited antibacterial effect on Staphylococci , potentially confirming the increased resistance of the bacterium to macrolides . But, the tested dermocosmetic not only reduced the number of Actinobacteria—it also reduced the number of Staphylococcus spp.…”

MRSA Isolates from United States Hospitals Carry dfrG and dfrK Resistance Genes and Succumb to Propargyl-Linked Antifolates

“…Minimal shifts in MIC for levofloxacin and up to 8-fold decrease in ciprofloxacin MIC indicate that NorA has minimal influence on fluoroquinolone resistance (Table S3) (Kaatz and Seo, 1995; Aeschlimann et al, 1999). mphC , a 2′-phosphotransferase which directly inactivates the macrolides via phosphorylation determines selective macrolide resistance (erythromycin) in UCH 121, UCH 127 and HH1184, all clonally distinct isolates(Matsuoka et al, 2003; Juda et al, 2016). mphC is not commonly reported to confer macrolide resistance in human S. aureus isolates, instead it is more frequently reported in agricultural studies (Li et al, 2015).…”