Phylogenetic analysis of streptococci in samples taken from the throat cultures of children in Turkey and the presence of mef(A), mef(E), erm(B) and erm(TR) genes in patients with Streptococcus pyogenes

Abstract

AbstractObjectiveFailure to achieve success with penicillin treatment in some cases observed in the pediatric group and the decrease in macrolide activity have brought about the necessity of a new study aiming to differentiate bacteria at the species level in throat infections. Antibiotic resistance studies are of great importance for the treatment of bacterial infections in terms of public health and rational antibiotic use. For this purpose, we aimed to perform a species-level differentiation of streptococci isolated from the throat cultures of pediatric patients presenting to our hospital, to determine their antibiotic susceptibility, and to identify the macrolide resistance genes of mef(A), mef(E), erm(B) and erm(TR) in patients with Streptococcus pyogenes. The study included 51 samples taken from pediatric cases presenting with a sore throat as the patient group and 36 samples from children without this complaint as the control group.Material and MethodThe throat culture samples taken from 51 children presenting to the hospital with the complaint of sore throat were evaluated in the laboratory, and streptococcus was diagnosed using tests; gram staining, catalase and PYR, and the susceptibility profile was determined with the Kirby-Bauer disk-diffusion method. Bacteria were identified at the species level according to 16srRNA sequences, and possible macrolide resistance genes of mef(A), mef(E), erm(B) and erm(TR) were determined by PCR in species detected to have S. pyogenes.ResultsOur antibiotic susceptibility results were consistent with the general results reported in Turkey. The sequence analysis of bacteria was performed according to 16srRNA sequences, and S. pyogenes, Streptococcus pneumoniae, Streptococcus anginosus, Streptococcus agalactiae, and Streptococcus dysgalactiae were isolated. In patients with S. pyogenes, the genetic determinants of macrolide resistance, mef(A), mef(E), erm(B) and erm(TR), were investigated with the PCR method using primers specific to each gene. Different levels of expression were observed in five patients. Macrolide resistance in S. pyogenes, which is reported at various percentages in the world, was found to be 9.8% in our study.DiscussionThe results of our study show that penicillin resistance genes were found in five of the patients evaluated. When the anamnesis of these patients was examined, it was determined that there were patients that frequently presented to the hospital with throat infections and experienced re-infection within a few weeks after receiving treatment. The common discourse of clinicians is that there may be an unknown resistance development. Therefore, our research should be supported by new hypotheses and studies that are open to development.