Vaginal colonization by group B Streptococcus among pregnant women and antibiotic resistance profile in some hospitals in N’Djamena, Chad

Abstract

ABSTRACT Vaginal carriage of group B streptococcus in pregnant women is generally asymptomatic and often overlooked. This bacterium can cause severe infections in both mother and newborn, resulting in significant mortality and morbidity rates. This study aimed to evaluate the rate of asymptomatic carriage of group B streptococcus in pregnant women in Ndjamena and to assess the resistance profile of isolates obtained. Vaginal swabs collected from participants were subjected to bacteriological analysis. Bacteria were isolated on Columbia agar supplemented with fresh sheep blood, and the resulting colonies were subcultured under the same conditions to obtain pure colonies. Group B streptococcus identification was made using pure colonies and different techniques: control Gram stain, biochemical test (catalase), and the Lancefield test. Antibiogram was based on antibiotics frequently used to treat Group B Streptococcus infection and following EUCAST guidelines. Pregnant women (152) were enrolled in this study, aged from 14 to 38 years, predominantly represented by the age group [19-23 years] N = 48 (31.57%). The majority of women, 107 (70.39%), were housewives, and 100 (65.79%) of them had between 0 and 2 children. Gestational age ranged from 3 to 41 weeks of amenorrhea, and the most represented was [29 - 41 weeks] N= 81 (53.28%). The carriage rate was 21.05%, with cases of co-infection, the most frequent being Group B Streptococcus-Staphylococcus. The number of children per participant, abdominal pain, and itching were statistically associated with Group B Streptococcus carriage. The isolates showed a high level of antibiotic resistance, especially to β-lactams, and sensitivity to vancomycin. Asymptomatic carriage of Group B Streptococcus is a reality in pregnant women, and the isolated strains exhibit a concerning antibiotic resistance profile. Keywords: vaginal colonization, group B streptococcus, pregnant women, resistance profile, Chad.