mef(A) is the predominant macrolide resistance determinant in Streptococcus pneumoniae and Streptococcus pyogenes in Germany

Abstract

In this study, macrolide-resistant Streptococcus pneumoniae and Streptococcus pyogenes isolates from Germany were carefully characterised by susceptibility testing, phenotyping, polymerase chain reaction (PCR) and sequencing of macrolides resistance genes, and multilocus sequence typing (MLST). Of 2045 S. pneumoniae and 352 S. pyogenes isolates, 437 (21.4%) and 29 (8.2%), respectively, were found to be macrolide-resistant. Amongst the S. pneumoniae isolates, the most prevalent resistance marker was mef(A) (57.7%) followed by erm(B) (27.0%) and mef(E) (11.2%). Of note, the dual resistance mechanism mef(E)+erm(B) was found in a relatively high proportion (4.1%) of pneumococcal isolates. Amongst the S. pyogenes isolates, 31.0% carried mef(A), 34.5% erm(B) and 13.8% erm(A). Dissemination of a single clone [mef(A)-positive England(14)-9] has significantly contributed to the emergence of macrolide resistance amongst pneumococci in Germany.

Molecular Resistance Mechanisms of Macrolide-Resistant Invasive Streptococcus pneumoniae Isolates from Alaska, 1986 to 2010

“…While we observed a slight decrease in the prevalence of mef-positive isolates in the later time period (2005 to 2010), this observation coincided with a significant increase in the prevalence of isolates expressing both the erm(B) and mef(E) genes. This is consistent with data reported by Bley et al, who found that isolates harboring both resistance mechanisms carried the erm(B) gene and only the mef(E) gene but not mef(A) (34). There have been a number of reports of pneumococci harboring both the erm(B) and mef genes (13, 15-17, 21, 23, 35, 36).…”

Biological and Epidemiological Features of Antibiotic-Resistant Streptococcus pneumoniae in Pre- and Post-Conjugate Vaccine Eras: a United States Perspective

“…In the last decade, isolates with the dual resistance mechanism [both erm(B) and the mef gene] have been increasingly reported from the United States, Canada, South Africa, Mexico, and a number of countries in Asia and Europe (172,180). The prevalence of isolates in the United States carrying both genes increased as a result of the diversification and expansion of lineages of Taiwan 19F -14 (PMEN-14 clone) following conjugate vaccine introduction.…”

Macrolide resistance mechanisms inEnterobacteriaceae: Focus on azithromycin

“…Currently, the mef(A) gene ranks among the most frequently detected TMMR in both Enterobacteriaceae (Ojo et al, 2004) and Gram-positive microorganisms (Bley et al, 2011). MefA is able to extrude different macrolides of 14 and 15C but has no effect on those with 16C (Poole, 2005).…”