Determination of Streptococcus Agalactiae Resistance to Selective Antibiotics and Detection of Resistance Gene to Erythromycin Isolated from Vagina of Carrier Women in Yazd, Iran, 2015

Streptococcus agalactia (GBS, Group B streptococcus) is a bacterium usually found in the vagina, urinary and digestive tract. Colonization of GBS in mother's vagina may threat the newborn to acquire different infections such as pneumonia, meningitis and bacteremia.
The present analytical-descriptive study was performed using 100 vaginal specimen for detection and phenotyping resistance of GBS to penicillin, erythromycin, clindamycin and tetracycline by Kerby-Bauer method. Resistance genes to erythromycin erm A, erm B, mef A using molecular analysis was also evaluated.
Findings: Tetracycline was found to be the most resistance and penicillin the least. Resistance to erythromycin was 8, clindamycin 10, tetracycline 95 and penicillin 1 percent. That genotypic of erm B 23% and erm A 38% was the most resistance, but, the least resistance gene was mef A with 1%.
This study revealed that the sensitivity of penicillin to GBS is satisfactory, but it seems that resistance of this bacterium to clindamycin, erythromycin is increasing. In addition, it was found that the gene erm A was the most prevalence gene concerning erythromycin resistance.