Background: Abnormal vaginal discharge is a prevalent gynecological complaint among women of reproductive age, often leading to diagnostic uncertainty. Accurate identification of causative bacterial pathogens and their antibiotic susceptibility is crucial for effective management and prevention of severe complications.

Aim: This study aimed to isolate, identify, and determine the antibacterial susceptibility patterns of aerobic bacterial pathogens causing abnormal vaginal discharge among reproductive-age women attending a tertiary care hospital.

Methods: A prospective study was conducted from January to June 2024 at the Department of Microbiology, GMC & GGH, Ongole. A total of 100 reproductive-age women presenting with abnormal vaginal discharge were included. Two high vaginal swabs were collected from each participant for Gram staining and culture. Isolates were identified using biochemical tests, and antibiotic susceptibility was determined by Kirby-Bauer disc diffusion method.

Results: Out of 100 participants, 73 showed culture positivity. Gram-negative bacilli accounted for 59% of isolates (E. coli 27%, Klebsiella 18%, Pseudomonas 14%), Gram-positive cocci 29% (Staphylococcus aureus 16%, Enterococcus spp. 7%, CONS 5%), and yeast (Candida species) 12%. Gram-negative isolates exhibited highest sensitivity to Meropenem (100%), Piperacillin-Tazobactam (90%), and Amikacin (70-82%). Among Gram-positive isolates, Vancomycin sensitivity was 100%. S. aureus was most sensitive to Azithromycin (83%), whereas Enterococcus spp. showed complete sensitivity to Gentamicin. Extended-spectrum beta-lactamase (ESBL) production was observed in 60% E. coli and 38% Klebsiella isolates. Methicillin-resistant strains constituted 33% of S. aureus and 100% of CONS isolates.

Conclusion: The study identified E. coli, Klebsiella, and S. aureus as predominant pathogens associated with abnormal vaginal discharge. High sensitivity to Meropenem and Vancomycin highlights their potential therapeutic roles. Regular monitoring of antimicrobial resistance, especially ESBL and MRSA prevalence, is essential for effective clinical management and reducing complications.