Molecular epidemiology, antimicrobial susceptibilities and resistance mechanisms of Streptococcus pyogenes isolates resistant to erythromycin and tetracycline in Spain 19942006Report as inadecuate




Molecular epidemiology, antimicrobial susceptibilities and resistance mechanisms of Streptococcus pyogenes isolates resistant to erythromycin and tetracycline in Spain 19942006 - Download this document for free, or read online. Document in PDF available to download.

BMC Microbiology

, 12:215

Clinical microbiology and vaccines

Abstract

BackgroundGroup A Streptococcus GAS causes human diseases ranging in severity from uncomplicated pharyngitis to life-threatening necrotizing fasciitis and shows high rates of macrolide resistance in several countries. Our goal is to identify antimicrobial resistance in Spanish GAS isolates collected between 1994 and 2006 and to determine the molecular epidemiology emm-T typing and PFGE and resistance mechanisms of those resistant to erythromycin and tetracycline.

ResultsTwo hundred ninety-five out of 898 isolates 32.8% were erythromycin resistant, with the predominance of emm 4T4, emm 75T25, and emm 28T28, accounting the 67.1% of the 21 emm-T types. Spread of emm 4T4, emm 75T25 and emm 28T28 resistant clones caused high rates of macrolide resistance. The distribution of the phenotypes was M 76.9%, cMLSB 20.3%, iMLSB 2.7% with the involvement of the erythromycin resistance genes mefA 89.5%, msrD 81.7%, ermB 37.3% and ermA 35.9%.

Sixty-one isolates were tetracycline resistant, with the main representation of the emm 77T28 among 20 emm-T types. To note, the combination of tetM and tetO tetracycline resistance genes were similar to tetM alone reaching values close to 40%. Resistance to both antibiotics was detected in 19 isolates of 7 emm-T types, being emm 11T11 and the cMLSB phenotype the most frequent ones. ermB and tetM were present in almost all the strains, while ermA, mefA, msrD and tetO appeared in less than half of them.

ConclusionsSpanish GAS were highly resistant to macrolides meanwhile showed minor resistance rate to tetracycline. A remarkable correlation between antimicrobial resistance and emm-T type was noticed. Clonal spread of emm 4T4, emm 75T25 and emm 28T28 was the main responsable for macrolide resistance where as that emm 77T28 clones were it to tetraclycline resistance. A wide variety of macrolide resistance genes were responsible for three macrolide resistance phenotypes.

KeywordsGASemm genePFGEMacrolide resistanceTetracycline resistanceElectronic supplementary materialThe online version of this article doi:10.1186-1471-2180-12-215 contains supplementary material, which is available to authorized users.

Download fulltext PDF



Author: VirginiaRubio-Lpez - SylviaValdezate - Davidlvarez - PilarVillaln - MaraJosMedina - CeliaSalcedo - Juan-AntonioSez-Nieto

Source: https://link.springer.com/



DOWNLOAD PDF




Related documents