Bacterial Profile and Antibiotic Susceptibility Patterns of Urogenital Isolates Among Women With Preterm Labor at a Tertiary Hospital in Southwestern Uganda

Abstract

Background: Pathogenic bacterial colonization of the urogenital tract during pregnancy may lead to infection and inflammation, contributing to adverse obstetric and neonatal outcomes such as preterm labor, preterm premature rupture of membranes, chorioamnionitis, neonatal sepsis, and perinatal mortality. Early identification of bacterial isolates and their antibiotic susceptibility patterns is essential for guiding appropriate antimicrobial therapy, reducing maternal and neonatal morbidity, and informing local treatment guidelines. This study aimed to determine the bacterial isolates colonizing the urogenital tract and their antibiotic susceptibility patterns among women presenting with preterm labor at Mbarara Regional Referral Hospital. Methods: This cross-sectional study consecutively enrolled 156 women with preterm labor between November 2022 and April 2023. Midstream urine samples, endocervical swabs, and high vaginal swabs were collected for bacterial culture, identification, and antibiotic susceptibility testing. Data were analyzed descriptively, and bacterial isolates and antibiotic susceptibility patterns were summarized as frequencies and percentages. Results: Bacteria were isolated from urine samples in 43/156 (27.6%) participants and from genital tract specimens in 75/156 (48.1%). The predominant urinary isolates were Klebsiella spp. (20/43, 46.5%) and Staphylococcus aureus (16/43, 37.2%), while Escherichia coli accounted for 4/43 (9.3%) of urinary isolates. In the genital tract, S. aureus was the most frequently isolated organism (43/75, 57.3%), whereas Proteus spp. (1/75, 1.3%) and Pseudomonas spp. (1/75, 1.3%) were the least common. The predominant urinary and genital tract isolates demonstrated high resistance to ampicillin and azithromycin but were generally susceptible to ceftriaxone, gentamicin, and ciprofloxacin. Conclusion: Staphylococcus aureus and Klebsiella spp. were the predominant urogenital bacterial isolates among women with preterm labor. Most bacterial isolates were susceptible to gentamicin, ciprofloxacin, ceftriaxone, and ceftazidime but demonstrated high resistance to ampicillin and azithromycin. These findings highlight the need for routine culture and antibiotic susceptibility testing and may inform future updates of empirical antibiotic treatment guidelines in Uganda.