Pattern of Infection and Antibiotic Activity among Streptococcus agalactiae Isolates from Adults in Mashhad, Iran

Background: One of the main causes of sexually transmitted diseases is group B β- hemolytic streptococci (GBS) multiplying in the genital tracts. Penicillin is the most common drug for the treatment of infections caused by these bacteria, but in patients suffering from Penicillin allergy, Erythromycin and Clindamycin are used as alternative therapeutic drugs against GBS. Recently, resistance to these drugs has been reported more often. In this study, efforts have been made to determine the prevalence and antibiotic resistance of GBS. Methods: Modified Christie Atkins Munch-Petersen (CAMP) test was conducted on over ۲۴۰۰ samples of urine and discharge taken from vagina, urethra and prostate. The drug sensitivity was performed by double disk sensitivity tests to Bacitracin, Trimethoprim, and Sulfamethoxazole and then the resistant samples were investigated by E-test to determine the minimal inhibitory concentrations (MICs) value. Results: Twenty-three vaginal and ۱۰ urethral discharge, ۲۷urine and ۶ prostatic secretion samples were GBS positive. The most symbiotic microorganisms with GBS were strains of Enterococci (۹۰%), Staphylococcus saprophyticus (۲۵%) and Candida albicans (۶%). The disk diffusion method showed ۱۸ cases with Penicillin resistance (MIC: ۱.۵ mg/ml). Conclusion: Taken together, GBS carriers’ rate in this study was found ۲۰.۶۵% (۸.۲۴% men and ۱۲.۴% women). Furthermore, findings showed high-level resistance to Erythromycin and Clindamycin.