Pathogenic profile and drug susceptibility in urinary tract infection during pregnancy: a retrospective hospital-based comparative cohort study

Pregnant women are prone to urinary tract infection (UTI). Whether the pathogen spectrum and antibiotic resistance profiles of UTI differs between pregnant and non-pregnant women, as well as the sensitivity and drug resistance of pathogens to antibiotics, requires further clarification. Therefore, we aimed to compare the pathogen distribution and antibiotic resistance between pregnant and non-pregnant women with UTIs to provide evidence for the treatment of UTIs during pregnancy. From January 2016 to December 2023, 380 female inpatients aged 18 to 45 years who were clinically diagnosed with UTI in the nephrology department of our hospital were retrospectively analyzed. They were divided into pregnant and nonpregnant groups. The differences in etiology, drug sensitivity to antibiotics, drug resistance rates, complications and length of hospitalization between the two groups were analyzed. Of the 380 cases, pathogens were detected in 132, corresponding to a positive rate of 34.74%. Gram-negative bacteria were detected in 79 cases (59.85%). Among the 132 cases, 61 were positive for Escherichia coli (46.21%). There were 17 cases of extended-spectrum β-lactamase-positive E. coli, accounting for 27.87% of all E. coli cases. The resistance rates to ceftriaxone, ceftazidime, aztreonam, levofloxacin, cefoperazone/sulbactam and piperacillin/tazobactam were 44.26%, 29.51%, 27.87%, 26.23%, 1.64% and 0.00%, respectively, and the drug resistance rate to meropenem was 0.00%. Among the 187 pregnant women, positive bacterial cultures were identified in 76 cases, corresponding to a positive detection rate of 40.64%. Gram-negative bacteria were detected in 42 cases (55.26%), including 28 cases of E. coli (36.84%). ESBL -positive E. coli was detected in 9 cases (32.14%) and Klebsiella pneumoniae was detected in 7 cases (9.21%). There was 1 case of Citrobacter freundii, 3 cases of Proteus mirabilis, and 1 case of Acinetobacter johnsonii. There were 12 cases of gram-positive bacteria (15.79%) and 6 cases of Enterococcus faecium (7.89%). Gram-negative bacteria were the primary pathogens affecting pregnant and nonpregnant patients, and there was no significant difference between the two groups. The pregnant group tended to have more complications including hydronephrosis, anemia, hypoalbuminemia and a history of abortion. Notably, a higher proportion of pregnant patients had Mycoplasma infection (53.48%) than did nonpregnant patients (35.75%). Gram-negative bacteria are the primary causative pathogens of UTI in pregnant women, and the rate of bacterial drug resistance is high. The administration of antibiotics should be based on pregnant women’s conditions and on the epidemiological data of local pathogens.