Background & Objective: Antibiotic resistance, particularly in bacteria producing extended-spectrum beta-lactamases (ESBLs), is a major challenge in managing bacterial infections. Here we investigated the prevalence of antibiotic resistance and its patterns in Escherichia coli strains isolated from pregnant women attending Alzahra Hospital, Tabriz, Iran.
 Materials & Methods: This cross-sectional study was conducted on 100 vaginal samples collected from pregnant women. The samples were examined for identifying Escherichia coli and antibiotic resistance using microbiological tests and the E-TEST method. Additionally, the prevalence of the CTX-M, SHV, and TEM genes in ESBL-producing strains was determined using PCR.
Results:  Out of 100 samples, 45 (45%) were identified as Gram-negative, and 27 (27%) were confirmed to be Escherichia coli. Among the 27 E. coli strains, 9 (33.33%) were identified as ESBL producers. E-TEST results for the ESBL-producing strains revealed cefotaxime resistance ranging from 1 to 2 mg/mL and ceftazidime resistance ranging from 0.25 to 4 mg/mL. One strain showed resistance to very high concentrations (up to 256 mg/mL). The prevalence of the CTX-M and TEM genes in the ESBL-producing strains was 22.22% and 88.88%, respectively, while the SHV gene was not detected in any strain. Two strains carried both the CTX-M and TEM genes simultaneously. The overall prevalence of CTX-M and TEM genes in all isolated E. coli strains was 7.4% and 29.62%, respectively.
Conclusion:  These findings highlight the necessity for efficient approaches to manage antibiotic resistance.