Antimicrobial Resistance Profile of Uro-Genital Bacterial Isolates in Southern Libreville, Gabon: A Cross-Sectional Study Based on Minimum Inhibitory Concentrations (2025)
Background: Antimicrobial resistance (AMR) is an escalating public health threat in sub-Saharan Africa, where local surveillance data remain limited, including in Gabon. This study aimed to describe the antimicrobial resistance profile of bacterial isolates from uro-genital infections in the southern Libreville region over the year 2025. Methods: Retrospective cross-sectional study of 477 clinical specimens processed with an automated identification and susceptibility testing system. After excluding yeasts (n = 199), 278 bacterial isolates were included. Resistance status per antibiotic class was determined from resistance phenotypes and raw minimum inhibitory concentrations (MICs); MIC50 and MIC90 values were calculated for key antibiotics in Escherichia coli, Klebsiella pneumoniae, and Staphylococcus spp. Proportions are reported with 95% confidence intervals (Wilson method). Results: The population was predominantly female (76.3%), with urine cytobacteriological examination (43.8%) and combined genito-urinary specimens (40.7%) as the leading specimen types. Escherichia coli (35.6%) and Klebsiella pneumoniae (14.7%) were the most frequent bacterial isolates. High resistance was observed for trimethoprim-sulfamethoxazole (98.3%) and beta-lactams (79.3%), with an MIC90 for cefotaxime and ceftriaxone ≥ 64 mg/L in both E. coli and K. pneumoniae, suggestive of a high prevalence of ESBL production. More than half of all bacterial isolates (56.5%) were resistant to at least three antibiotic classes, meeting a standard multidrug-resistance (MDR) definition. Direct analysis of vancomycin MICs (MIC50 0.75 - 1 mg/L, MIC90 1 mg/L) revealed no glycopeptide resistance among Staphylococcus spp., contradicting an initially discordant automated derived indicator. Conclusion: These data confirm a high level of resistance to first-line antibiotics among uropathogens in the southern Libreville region, consistent with published data from other Gabonese and sub-Saharan African sites, and highlight fosfomycin, nitrofurantoin, and carbapenems as valuable therapeutic options of last resort.Subject AreasMicrobiology
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