High Prevalence of β-Lactam Resistance in uropathogenic Escherichia coli Strains Isolated from Pregnant Women with Acute Cystitis in Butembo, Democratic Republic of Congo

Background Acute cystitis during pregnancy is a prevalent clinical concern associated with significant maternal and fetal complications. In the Democratic Republic of Congo (DRC), rising antimicrobial resistance threatens the efficacy of empiric therapies. This study aimed to characterize the in vitro susceptibility of uropathogenic Escherichia coli (UPEC) isolates from pregnant women in Butembo, DRC, to commonly prescribed β-lactam antibiotics. Methods A cross-sectional study was conducted over a six-month period in 2017.Urine samples were collected from pregnant women at their first prenatal care visit at Matanda Hospital. Samples were cultured on Cystine Lactose Electrolyte Deficient (CLED) agar, and isolates were identified using standard biochemical tests. The minimum inhibitory concentrations (MICs) of five β-lactam antibiotics were determined via the broth microdilution method. Results were interpreted according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Results Of the 21 samples collected,18 showed significant bacterial growth, yielding a culture positivity rate of 85.7%. Six of these isolates were confirmed as E. coli, representing a prevalence of 33.3% among culture-positive specimens. All six E. coli strains exhibited complete resistance to amoxicillin, amoxicillin-clavulanate, cefotaxime, and ceftriaxone. In contrast, all isolates remained susceptible to the ceftriaxone-sulbactam combination. Hierarchical clustering of MIC data revealed two distinct groups with different resistance profiles. A strong and statistically significant correlation was observed between the MICs of the tested antibiotics (p < 0.001). Conclusion This study demonstrates a high prevalence of multi-drug resistance among uropathogenic E. coli in Butembo, likely mediated by extended-spectrum β-lactamase production. The sustained efficacy of ceftriaxone-sulbactam identifies it as a potential therapeutic option. These findings underscore an urgent need for enhanced antimicrobial stewardship and robust resistance surveillance programs in the region.