Ann Lab Med.  2015 Jan;35(1):57-61. 10.3343/alm.2015.35.1.57.

Detection of the Efflux-Mediated Erythromycin Resistance Transposon in Streptococcus pneumoniae

• Azadegan A
• Ahmadi A
• Lari AR
• Talebi M

• KMID: 2363148
• DOI: http://doi.org/10.3343/alm.2015.35.1.57

Abstract

BACKGROUND
The present analysis focuses on phenotypic and genotypic characterizations of efflux-mediated erythromycin resistance in Streptococcus pneumoniae due to an increase in macrolide resistance in S. pneumoniae worldwide.
METHODS
We investigated the prevalence of efflux-mediated erythromycin resistance and its relevant genetic elements from 186 specimens of S. pneumonia isolated from clinical and normal flora from Tehran, Iran. The presence of erythromycin resistance genes was tested by PCR with two sets of primers, specific for erm(B) and mef(A/E), and their genetic elements with tetM, xis, and int genes. Isolates were typed with the BOX PCR method and tested for resistance to six antibiotics.
RESULTS
Antibiotic susceptibility tests revealed that 100% and 47% isolates were resistant to tetracycline and erythromycin, respectively. The erythromycin and clindamycin double-disc diffusion test for macrolide-lincosamide-streptograminB (MLSB) resistance phenotype showed 74 (84%) isolates with the constitutive MLSB phenotype and the remaining with the M phenotype. BOX PCR demonstrated the presence of 7 types in pneumococci with the M phenotype. Fourteen (16%) isolates with the M phenotype harbored mef(A/E), tetM, xis, and int genes.
CONCLUSIONS
The present results suggest dissemination of polyclonal groups of S. pneumoniae with the M phenotype carrying resistance genes attributed to transposon 2009.

Keyword

Erythromycin; mef(A/E); Streptococcus pneumoniae

MeSH Terms

Anti-Bacterial Agents/*pharmacology
Bacterial Proteins/genetics
DNA, Bacterial/metabolism
Drug Resistance, Multiple, Bacterial/*genetics
Erythromycin/*pharmacology
Genotype
Humans
Microbial Sensitivity Tests
Phenotype
Pneumococcal Infections/microbiology/pathology
Polymerase Chain Reaction
Streptococcus pneumoniae/*drug effects/*genetics/isolation & purification
Tetracycline/pharmacology
Anti-Bacterial Agents
Bacterial Proteins
DNA, Bacterial
Erythromycin
Tetracycline