Maternal vaginorectal colonization by Group B Streptococcus and Listeria monocytogenes and its risk factors among pregnant women attending tertiary hospital in Mwanza, Tanzania

Abstract

Background: Group B streptococcus (GBS) and Listeria monocytogenes are members of the normal microbes of the female genital tract. During labour GBS and Listeria monocytogenes may infect the new-borns, leading to neonatal sepsis and meningitis. So far, there is no report on prevalence of GBS and Listeria monocytogenes among pregnant women in Mwanza. The objective of the study was to determine the magnitude of Group B Streptococcus and Listeria monocytogenes and its associated factors at Bugando Medical Centre, Mwanza, Tanzania.

Methods: The study was a cross section conducted from 1^st November 2011 to 31^st May 2012 at Bugando Medical Centre in Mwanza, Tanzania.  Vaginal and rectal swabs were obtained and cultured on 5% sheep blood agar and susceptibility testing done using disk diffusion technique.

Results: A total of 295 pregnant women participated in the study. GBS strains were isolated from 28 (9.49%) and only two (0.68%) had isolates of Listeria spp. All GBS and Listeria spp. isolates were sensitive to penicillin and ampicillin. Eight GBS isolates were resistant to erythromycin (28.6%), seven GBS isolates were resistant to clindamycin (25%) and 15 of GBS isolates were resistant to tetracycline (53.6%). One Listeria spp isolate was resistant to cotrimoxazole. Pregnant women with no formal education and those dwelling in rural areas were more frequently colonized by GBS.

Conclusion: There is a significant prevalence rate of GBS culture positive at Bugando Medical Centre with demonstrable resistant to some common antibiotics (tetracycline, erythromycin and Clindamycin). Screening for GBS should be instituted in Tanzania between 35 and 37 weeks of gestation coupled with regular check up for antimicrobial susceptibility pattern due to emerging resistance toward existing antibiotics.