Maternal rectovaginal colonization with group B streptococcus (GBS) is a main risk factor for vertical transmission of GBS to newborns and life-threatening neonatal invasive diseases. The aim of this study was investigation of the prevalence of anorectal and vaginal colonization with GBS in late of pregnancy by culture-based and polymerase chain reaction (PCR) methods and antimicrobial susceptibility patterns of the GBS isolates in Rasht, Iran.
We analyzed 245 anorectal and vaginal swab samples separately from pregnant women at 35 to 37 weeks of gestation. All samples were cultured after enrichment in a selective Todd-Hewitt broth and then assayed by phenotypic characterizations and PCR method for cfb conserved gene. Antimicrobial susceptibility was performed using the Kirby–Bauer method.
In total of 245 vaginal samples, 19 (7.8%) were positive based on culture method and 28 (11.4%) by PCR method. Among 245 rectal samples, 24 (9.8%) were positive by culture and 29 (11.8%) samples were positive by PCR. Of 245 pregnant women studied were found to have 9.7% GBS rectovaginal by culture and 15.9% by PCR methods. All GBS isolates were sensitive to ampicillin (77.2%) and vancomycin (72.2%) and were resistant to Penicillin (88.6%), ceftriaxone (75%), clindamycin (95.4%), azithromycin (86.3%), tetracycline (61.3%), erythromycin (47.7%), and levofloxacin (27.2%).
The results of this study indicate that the frequency of GBS isolation from rectal samples was higher than vaginal samples by both culture and PCR. Our study recommended intrapartum antibiotic prophylaxis against GBS infections based on ampicillin or vancomycin for GBS carriers in Rasht.
From the *Department of Microbiology, Faculty of Medicine,
†Reproductive Health Research Center, Department of Obstetrics & Gynecology, Alzahra Hospital, School of Medicine,
‡Department of Social Medicine, Faculty of Medicine, Guilan University of Medical Sciences, Rasht;
§Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan;
∥Infectious and Tropical Disease Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar-Abbas; and
¶Cellular and Molecular Research Center, Faculty of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Correspondence to: Raheleh Sheikhi, PhD, Department of Microbiology, School of Medicine, Guilan University Complex, Tehran Rd, Km 6th, Rasht, Guilan, Iran. E-mail: firstname.lastname@example.org.
The authors have no conflicts of interest to disclose.