Antibacterial therapy for patients with obstetric peritonitis

Background

Obstetric peritonitis remains a leading cause of maternal mortality, developing predominantly after cesarean section. Despite advancements in surgical techniques and intensive care, the mortality rate for generalized forms reaches 20–40%. Key challenges today are the global rise in antibiotic resistance and a lack of regional data on pathogen spectrum, which complicates the choice of effective empirical antibacterial therapy.

Aim

The aim of this study was to develop antibacterial therapy regimens for obstetric peritonitis based on an analysis of regional data on pathogen structure and antimicrobial susceptibility (using materials from Krasnoyarsk and Krasnoyarsk Krai).

Methods

This retrospective and prospective study (January 2018 – December 2025) included 58 patients with obstetric peritonitis. The study material consisted of abdominal and pelvic exudate obtained during surgical treatment. Pathogen identification was performed using MALDI-TOF mass spectrometry, and antibiotic susceptibility was determined using the Vitek 2 Compact analyzer or the disk diffusion method in accordance with domestic guidelines.

Results

Gram-negative bacterial monocultures (44.8%), Gram-positive monocultures (37.9%), and microbial associations (17.2%) dominated the etiological structure. The most frequently isolated pathogens were Staphylococcus epidermidis (22.4%), Enterococcus faecalis (20.7%), Proteus mirabilis (20.7%), and Escherichia coli (10.3%). Problematic pathogens identified: included extended-spectrum beta-lactamase (ESBL)-producing E. coli (33.3% among isolated strains of this species), vancomycin-resistant enterococci (16.7%), and methicillin-resistant staphylococci (84.6% of all S. epidermidis isolates). High resistance rates were observed for E. coli to ciprofloxacin and ampicillin/sulbactam (83.3%), and for E. faecalis to fluoroquinolones (75%) and gentamicin (66.7%). Based on these findings, carbapenems (imipenem/cilastatin) are recommended as the drugs of choice, and in case of inefficacy, combinations with aminoglycosides or anti-MRSA agents are advised.

Conclusion

Regional variations in the microbial spectrum and high levels of antibiotic resistance dictate the need for empirical use of carbapenems in obstetric peritonitis. Efficacy assessment within 48–72 hours followed by therapy de-escalation after obtaining microbiological results is mandatory.