Streptococcus agalactiae carriage, serotype distribution and associated antibiogram among pregnant and non-pregnant women in Jos city, Nigeria

Abstract

Background: Streptococcus agalactiae (S. agalactiae) largely colonizes the gastrointestinal and genitourinary tissues and poses an increased risk for early-onset and late-onset sepsis in neonates delivered by colonized mothers.  This comparative cross-sectional study aimed to determine the S. agalactiae carriage rate, serotypes, as well as antimicrobial resistance (AMR) of the isolates among pregnant and non-pregnant women in Jos metropolis, Nigeria.

Methodology: High vagina and anorectal swab samples were collected from 200 pregnant women and 100 non-pregnant women. Isolates were identified and characterized biochemically and serologically. Epsilometer test was used to determine the antimicrobial susceptibility of isolates. Sociodemographic variables of participants were collated through the structured questionnaire.

Results: Of all the participants, a prevalence of 3.0% S. agalactiae carriage was obtained (3.5% and 2.0% in pregnant and non-pregnant women, respectively). The isolation rate of GBS from the high vagina was higher (2.0%) compared to the anorectum (1.0%). There was no significant association between the isolation rate with the age of subjects, sample type, and trimester of pregnant women (P>0.05). The serotypes distributions of the S. agalactiae isolates were; Ia (22.2%), II (33.3%), III (33.3%) and IX (11.1%). The highest antimicrobial susceptibility of the isolates was to benzylpenicillin (88.9%), clindamycin (88.9%) and least to ampicillin (66.7%).

Conclusion:These findings revealed a moderate level of S. agalactiae colonization, low AMR and varied serotypes. Most of the isolates were susceptible to benzylpenicillin, clindamycin, ampicillin, and erythromycin. The screening of pregnant women during antenatal visits should be encouraged to detect infections and minimize potential transmissions to neonates.