Antibiotic Susceptibility Pattern of Anovaginal Isolates of Streptococcus agalactiae from Pregnant Women in Their Late Third Trimester

Abstract

Group B streptococcus (GBS) neonatal sepsis is a serious disease causing newborn mortality and long‐term neurologic sequelae. The Centers for Disease Control and Prevention (CDC) recommend third‐trimester GBS screening and intrapartum antibiotic prophylaxis for high‐risk women. The aim of our study was to identify colonized pregnant women and assess the prevalence of GBS in pregnancy and the susceptibility pattern of GBS in southern Taiwan. We performed the study at the Department of Obstetrics and Gynecology, Kaohsiung Women and Children' Hospital, between January and December 2002. Distal vaginal and anorectal swabs were obtained from pregnant women at 35 or more weeks' gestation. Swabs were used to inoculate selected medium, which was subcultured onto sheep' blood agar after 24 hours. Sensitivity to azithromycin, clindamycin, erythromycin, ofloxacin, penicillin G, tetracycline, trimethoprim/sulfamethoxazole, and vancomycin was tested using the disc diffusion method. Of the 374 pregnant women enrolled in the study, 56 (15%) had positive cultures for GBS. Antibiotic susceptibility was as follows: azithromycin 44.6%, clindamycin 66.1%, erythromycin 70.5%, ofloxacin 70.5%, penicillin G 60.7%, tetracycline 39.3%, trimethoprim/sulfamethoxazole 35.7%, and vancomycin 100%. The CDC recommend penicillin as the first choice for intrapartum prophylaxis, with erythromycin and clindamycin as alternatives for penicillin‐allergic patients. There has been increasing resistance to these antibiotics among GBS. Third‐trimester GBS screening and susceptibility testing for pregnant women should be considered.

Phenotypic traits and comparative detection methods of vaginal carriage of Group B streptococci and its associated micro-biota in term pregnant Saudi women

“…The GBS strains-resistance trend toward these antibiotics is important, since erythromycin is considered first-line prophylaxis for those with allergy to penicillin. In Brazil, however, Castellano-Filho et al (2010) reported 22.7 and 50% of GBS isolates were resistant to erythromycin and clindamycin, respectively, while in Taiwan, Fu et al (2004) and Simoes et al (2007) reported that as much as 39.9% of GBS isolates were resistant to penicillin G. This highlights, the importance of ongoing population-based monitoring for trends in Talat et al 411 antimicrobial resistance (Edwards, 2006;Barcaite et al, 2008). The fact that most of our GBS isolates were resistant to gentamicin or tetracycline is in agreement with literature data (Morales et al, 1999;Al Huseini et al, 2000;Edwards, 2006;Shabayek et al, 2009) and thereby emphasizing GBS-intrinsic resistance to these antibiotics (Al Huseini et al, 2000).…”

“…Susceptibility was performed, and results interpreted according to Clinical Laboratory Standard Institute CLSI guidelines. Each strain had its susceptibility classified as sensitive, intermediate or resistant to each one of these antibiotics (Morales et al, 1999;Clinical and Laboratory Standards Institute (CLSI), 2007;Fu et al, 2004). The antibiotic tested were, 10 μg Ampicillin, 30 μg Cefepime, 30 μg ceftriaxone, 2 μg clindamycin, 15 μg erythromycin, 10 μg gentamicin, 300 μg nitrofurantoin, 30 μg Tetracycline and 30 μg vancomycin.…”