Urinary tract infections (UTIs) are among the most common bacterial infections encountered during pregnancy and remain a significant contributor to maternal and neonatal morbidity worldwide.[1] Pregnancy is associated with profound anatomical, physiological, and immunological alterations that increase susceptibility to infection. Hormonal effects—particularly progesterone-induced relaxation of ureteral smooth muscle—along with mechanical compression by the enlarging uterus, result in urinary stasis and vesicoureteral reflux, thereby facilitating bacterial colonization and ascending infection.[2] Additional factors such as glycosuria, altered urinary pH, and reduced bladder tone further enhance microbial growth.[3,4] As a consequence, pregnant women are at risk of both asymptomatic bacteriuria and symptomatic infections, including cystitis and pyelonephritis. The reported prevalence of UTI in pregnancy varies widely, ranging from 4% to 47%, reflecting differences in geographic location, socioeconomic conditions, hygiene practices, and diagnostic criteria.[5,6] If left untreated, UTIs may lead to serious obstetric and neonatal complications, including preterm labor, intrauterine growth restriction, low birth weight, neonatal sepsis, and maternal pyelonephritis.[3,4] Importantly, asymptomatic bacteriuria—although clinically silent—has been strongly associated with progression to pyelonephritis and adverse pregnancy outcomes, underscoring the need for routine screening and timely intervention. Escherichia coli is consistently reported as the predominant uropathogen in pregnancy, accounting for approximately 70–90% of infections, owing to its virulence determinants such as adhesins, fimbriae, and hemolysins that facilitate adherence to the uroepithelium.[7,8] Other frequently isolated organisms include Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus saprophyticus, Enterococci, and Group B Streptococcus, with regional variations in pathogen distribution and antimicrobial susceptibility.[9] The increasing emergence of multidrug-resistant uropathogens has further complicated management, particularly in pregnancy, where antibiotic choices are limited due to fetal safety concerns.[10] Widespread empirical and irrational antibiotic use has contributed to rising resistance against commonly prescribed β-lactams, cephalosporins, and fluoroquinolones, while agents such as nitrofurantoin and amikacin have retained comparatively better efficacy.[10–12] Accurate diagnosis and appropriate antimicrobial therapy are therefore critical. While conventional urine culture remains the diagnostic gold standard, recent molecular studies using next-generation sequencing have challenged the concept of urinary sterility and highlighted the limitations of culture-based methods in detecting fastidious or low-abundance organisms.[13–15] From a public health perspective, continuous surveillance of uropathogens and their resistance patterns is essential to guide empirical therapy, strengthen antibiotic stewardship, and reduce maternal and neonatal complications.[16,17] In this context, the present study was undertaken to evaluate the bacteriological profile of UTIs in pregnant women and to assess the antimicrobial susceptibility patterns of the isolated pathogens in a tertiary care setting. By generating localized data, this research aims to contribute to regional antibiotic stewardship efforts and support rational antibiotic prescribing in antenatal care. Aims and Objectives Primary Objective • To identify and characterize the bacterial pathogens causing urinary tract infections among pregnant women using standard microbiological techniques. Secondary Objectives • To determine the prevalence of significant bacteriuria and assess the distribution of uropathogens across different trimesters and age groups. • To evaluate the antimicrobial susceptibility profiles of isolated pathogens and identify emerging patterns of antibiotic resistance.

This was a retrospective cross-sectional study conducted in the Department of Microbiology, Government Medical College (GMC) Kathua, in collaboration with the Department of Obstetrics and Gynaecology, Associated Hospital GMC Kathua. The study covered a period of two years (April 2023–March 2025). Study Population The study population included pregnant women attending the antenatal clinic (ANC) during the study period who presented with symptoms suggestive of UTI or were screened for asymptomatic bacteriuria. Women who had received antibiotics within the last two weeks were excluded from this study. Sample Collection Clean-catch midstream urine samples were collected in sterile wide-mouthed universal containers, following standard aseptic precautions. Patients were instructed to wash their hands and clean the perineal area before collection, as per standard protocols. Samples were transported promptly and processed within 2 hours of collection. In case of delay, specimens were stored at 4°C until processing. Microbiological Processing Semi-quantitative culture was performed using a calibrated sterile nichrome loop delivering 0.01 mL of urine. Samples were inoculated onto CLED agar, MacConkey agar, and blood agar plates. Plates were incubated aerobically at 37°C for 24 hours. Significant bacteriuria was defined as growth of ≥105 CFU/mL for asymptomatic women and ≥103 CFU/mL for symptomatic women. Colony morphology, gram staining, and standard biochemical tests were employed for bacterial identification. Antimicrobial Susceptibility Testing (AST) Antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method on Mueller-Hinton agar following CLSI guidelines. The panel of antibiotics included ampicillin, amoxiclav, cefotaxime, ceftriaxone, ciprofloxacin, gentamicin, amikacin, nitrofurantoin, tetracycline, norfloxacin, and imipenem for Gram-negative isolates, and ampicillin, amoxiclav, linezolid, cotrimoxazole, chloramphenicol, and erythromycin for Gram-positive isolates. Data Analysis The prevalence of UTI was calculated as the proportion of culture-positive cases among total samples. Data were analyzed for distribution of bacterial pathogens, clinical characteristics, and antimicrobial susceptibility patterns. Results were presented as percentages and frequency tables.

The present study was conducted in the Department of Microbiology, GMC Kathua, in collaboration with the Department of Obstetrics and Gynaecology, Associated Hospital GMC Kathua, for a period of two years (April 2023–March 2025), to identify the uropathogens and their antibiogram profile among pregnant women. A total of 560 midstream urine samples were collected from pregnant women presenting with symptoms suggestive of urinary tract infection (UTI) over a two-year period. Of these, 112 (20%) samples showed significant bacterial growth on culture. The mean age of participants was 27.8 ± 5.4 years, with the majority in the second trimester (54%), followed by the third trimester (34%) and first trimester (12%) (Chart 1). Statistical analysis revealed a significant association between trimester and infection rate (χ² = 7.17, p = 0.028), suggesting that susceptibility to UTI increases notably during mid-pregnancy. Bacteriological Profile Among the 112 culture-positive isolates, Gram-negative bacilli accounted for 64.3%, while Gram-positive cocci comprised 35.7% of all isolates. The predominant uropathogen was Escherichia coli (40.18%), followed by Staphylococcus aureus (19.64%), coagulase-negative staphylococci (15.18%), Klebsiella spp. (12.50%), Enterococci (8.93%), and Acinetobacter spp. (3.57%). Statistical analysis revealed a significant difference in the prevalence of E. coli compared to S. aureus (χ² = 10.73, p = 0.0013), confirming E. coli as the predominant uropathogen among pregnant women with UTI. Antimicrobial Susceptibility Pattern Antibiotic sensitivity testing revealed nitrofurantoin as the most effective agent against E. coli (80%), followed by norfloxacin (74%), amikacin (72%), and cefotaxime (63%). Klebsiella spp. demonstrated the highest susceptibility to norfloxacin (71%), while Acinetobacter spp. showed 100% sensitivity to amoxiclav, amikacin, and tetracycline (Chart 2). Statistical analysis revealed a highly significant difference in resistance patterns between β-lactam antibiotics and nitrofurantoin (χ² = 23.9, p < 0.00001), indicating that nitrofurantoin remains markedly more effective against E. coli infections compared to β-lactams. Among Gram-positive isolates, Staphylococcus aureus was maximally sensitive to cotrimoxazole (76%), erythromycin (73%), and linezolid (70%), whereas Enterococci spp. were highly sensitive to linezolid (82%) and moderately to norfloxacin (Chart 3). Resistance to β-lactam antibiotics, particularly ampicillin and ceftriaxone, was prominent across both Gram-negative and Gram-positive isolates, suggesting widespread β-lactamase activity and possible emergence of ESBL-producing strains. Table 1: Distribution of Bacterial Isolates in Pregnant Women with UTI (n = 112) Pathogen No. of isolates Percentage (%) E. coli 45 40.18 S. aureus 22 19.64 CONS 17 15.18 Klebsiella spp. 14 12.50 Enterococci 10 8.93 Acinetobacter 4 3.57

The present study delineates the bacteriological profile and antimicrobial resistance patterns of urinary tract infections (UTIs) among pregnant women attending a tertiary care center in North India. The overall prevalence of culture-positive UTI (20%) lies within the globally reported range of 4%–47%, reflecting regional variability influenced by hygiene practices, antenatal screening policies, and socioeconomic determinants.[1,5,6] Comparable prevalence rates have been reported from several Indian and low-resource settings, indicating that UTIs continue to represent a substantial burden during pregnancy despite routine antenatal care.[12,13,16] Escherichia coli emerged as the predominant uropathogen (40.18%), consistent with extensive literature identifying it as the leading cause of pregnancy-associated UTIs.[7–9] Its predominance is attributed to virulence determinants such as adhesins and fimbriae that facilitate uroepithelial attachment, compounded by pregnancy-induced urinary stasis and ureteral dilatation.[2,3,8] The notable isolation of Gram-positive cocci, particularly Staphylococcus aureus and coagulase-negative staphylococci, suggests an expanding etiological spectrum, possibly related to increased healthcare exposure, perineal colonization, and biofilm formation [5,14,16]. The presence of Klebsiella spp., Enterococci, and Acinetobacter spp. further highlights a polymicrobial trend and raises concerns regarding nosocomial transmission and multidrug resistance.[9,12] Antimicrobial susceptibility patterns revealed nitrofurantoin as the most effective agent against E. coli, corroborating findings from multiple regional and international studies where it remains a reliable first-line drug in pregnancy due to sustained efficacy and a favorable safety profile.[12,15,16] Amikacin and norfloxacin also demonstrated reasonable activity, supporting their role as alternative options. In contrast, high resistance to β-lactam antibiotics, particularly ampicillin and ceftriaxone, mirrors global reports of escalating β-lactamase and ESBL production among uropathogens.[12–14] Among Gram-positive isolates, preserved susceptibility to cotrimoxazole, erythromycin, and linezolid aligns with prior studies and underscores their continued clinical relevance.[5,13,15] A higher infection rate during the second trimester, with a statistically significant association, aligns with earlier studies identifying mid-pregnancy as a period of increased vulnerability due to maximal hormonal and anatomical urinary tract changes.[2,3,5,11] These findings support routine urine screening during this trimester to prevent progression to pyelonephritis and adverse obstetric outcomes [3,4,10]. Finally, while culture-based diagnostics remain the cornerstone of UTI detection, emerging evidence from next-generation sequencing highlights the complexity of the urinary microbiome and the possibility of undetected infections in culture-negative cases.[17,18] Incorporating molecular approaches in future research may enhance diagnostic accuracy and antimicrobial stewardship. Limitations and Future Perspectives While the study provides critical regional data, its retrospective design and single-center scope may limit generalizability. The absence of molecular resistance profiling (e.g., ESBL or carbapenemase gene detection) restricts understanding of underlying resistance mechanisms. Future studies incorporating molecular diagnostics or next-generation sequencing (17–19) could provide a more comprehensive picture of the urinary microbiome and uncover subclinical infections currently missed by culture-based methods.

This study highlights the continued predominance of E. coli and S. aureus as leading uropathogens in pregnancy and underscores a concerning resistance to commonly used β-lactams. Nitrofurantoin, amikacin, and norfloxacin remain effective options in the local setting. Continuous surveillance, antibiotic stewardship, and timely culture-based therapy are crucial to safeguard maternal and fetal health and curb the progression of antimicrobial resistance.

1. Matuszkiewicz-Rowińska J, Małyszko J, Wieliczko M. Urinary tract infections in pregnancy: old and new unresolved diagnostic and therapeutic problems. Arch Med Sci. 2015;11(1):67-77. 2. Cheung KL, Lafayette RA. Renal physiology of pregnancy. Adv Chronic Kidney Dis. 2013;20(3):209-14. 3. Bayih WA, Ayalew MY, Chanie ES, Abate BB, Alemayehu SA, Belay DM, et al. The burden of neonatal sepsis and its association with antenatal urinary tract infection and intra-partum fever among admitted neonates in Ethiopia: A systematic review and meta-analysis. Heliyon. 2021;7(2):e06121. 4. Khalesi N, Khosravi N, Jalali A, Amini L. Evaluation of maternal urinary tract infection as a potential risk factor for neonatal urinary tract infection. J Family Reprod Health. 2014;8(2):59-62. 5. Dube R, Al-Zuheiri STS, Syed M, Harilal L, Zuhaira DAL, Kar SS. Prevalence, Clinico-Bacteriological Profile, and Antibiotic Resistance of Symptomatic Urinary Tract Infections in Pregnant Women. Antibiotics (Basel). 2022;12(1):33. 6. Batmani S, Jalali R, Mohammadi M, Bokaee S. Prevalence and factors related to urinary incontinence in older adults women worldwide: a comprehensive systematic review and meta-analysis of observational studies. BMC Geriatr. 2021;21(1):212. 7. Zhou Y, Zhou Z, Zheng L, Gong Z, Li Y, Jin Y, et al. Urinary Tract Infections Caused by Uropathogenic Escherichia coli: Mechanisms of Infection and Treatment Options. Int J Mol Sci. 2023;24(13):10537. 8. Bloukh SI, Hassan NA, AlAni RS, Gacem SA. Urinary tract infection and antibiotic resistance among pregnant and Non-pregnant females in UAE. Research Journal of Pharmacy and Technology. 2021;14(1):461-5. 9. Popoola MA, Ohaeri B, Ojo IO, Babarimisa O. Preterm birth, prevention, prediction, care. European Journal of Medical and Health Sciences. 2023;5(1):6-10. 10. Al Kadri HM, El-Metwally AA, Al Sudairy AA, Al-Dahash RA, Al Khateeb BF, Al Johani SM. Antimicrobial resistance among pregnant women with urinary tract infections is on rise: Findings from meta-analysis of observational studies. J Infect Public Health. 2024;17(7):102467. 11. Mohapatra S, Venugopal SJ, Kalaivani M, Kant S, Tak V, Panigrahy R, et al; CAUTION-ED Study (Community-acquired UTI, Emerging Drug Resistance). Antibiotic resistance of uropathogens among the community-dwelling pregnant and nonpregnant female: a step towards antibiotic stewardship. BMC Infect Dis. 2022;22(1):939. 12. Kusin SB, Fan EM, Prokesch BC, Christie AL, Zimmern PE. Empiric versus culture-based antibiotic therapy for UTIs in menopausal women. World J Urol. 2023;41(3):791-796. 13. Gasiorek M, Hsieh MH, Forster CS. Utility of DNA Next-Generation Sequencing and Expanded Quantitative Urine Culture in Diagnosis and Management of Chronic or Persistent Lower Urinary Tract Symptoms. J Clin Microbiol. 2019;58(1):e00204-19. 14. Pearce MM, Hilt EE, Rosenfeld AB, Zilliox MJ, Thomas-White K, Fok C, et al. The female urinary microbiome: a comparison of women with and without urgency urinary incontinence. mBio. 2014;5(4):e01283-14. 15. Moustafa A, Li W, Singh H, Moncera KJ, Torralba MG, Yu Y, et al. Microbial metagenome of urinary tract infection. Sci Rep. 2018 Mar;8(1):4333. 16. Ribeiro-do-Valle CC, Bonet M, Brizuela V, Abalos E, Baguiya A, Bellissimo-Rodrigues F, et al.; WHO GLOSS research group. Aetiology and use of antibiotics in pregnancy-related infections: results of the WHO Global Maternal Sepsis Study (GLOSS), 1-week inception cohort. Ann Clin Microbiol Antimicrob. 2024;23(1):21. 17. Bratosin F, Folescu R, Krupyshev P, Popa ZL, Citu C, Ratiu A, et al. Comparative Analysis of Microbial Species and Multidrug Resistance Patterns Associated with Lower Urinary Tract Infections in Preterm and Full-Term Births. Microorganisms. 2024;12(1):139. 18. Natasha Sawhney, Rahul Prabhas, Varsha A Singh. Bacteriological profile of Urinary Tract Infections in pregnant women – Future Challenges. International Journ Journal of Recent Trends in Science and Technology May; 23(1):01-05