Determination of antimicrobial resistance genes in patients with infected miscarriage. A rapid identification and optimized empirical therapy

BACKGROUND: The infectious factor during pregnancy remains the leading cause not only of maternal mortality, but also of premature pregnancy loss and subsequent reproductive function impairment. Patients with infected miscarriage represent a special cohort in terms of complexity of clinical decision-making, while the choice of antimicrobial chemotherapy is particularly difficult in conditions of accumulation of scientific knowledge about the main microbial agents. For adequate treatment, it is essential to use all modern methods of microbiota diagnosis and conduct regular monitoring of microorganism resistance in order to update empirical schemes of antibacterial therapy.

AIM: The aim of this study was to evaluate the correlation relationship between antimicrobial resistance genes and identified microbial agents in patients with infected miscarriage in order to optimize empirical antimicrobial chemotherapy.

MATERIALS AND METHODS: We prospectively studied 42 samples of genital tract discharge in patients with infected miscarriage. The classical culture method was used to determine microorganism sensitivity to standard antibacterial drugs by the disc diffusion test. A molecular genetic study of the species composition of clinically significant microbial agents and genes of resistance to β-lactam and glycopeptide antibiotics was performed using Femoflor Screen and BakRezista GLA test systems (“DNA-Technology” LLC., Russia), respectively.

RESULTS: In the cultural study, one microbial agent was identified in 59.5% of cases, two in 40.0% of cases, and three in 7.1% of cases. The following microorganisms were most frequently identified: Enterococcus spp. in 25.0% of cases, Esherichia coli in 16.7% of cases, and Candida spp. in 11.7% of cases. During the molecular genetic study, Lactobacillus spp. were identified in 64.3% of the samples, the microorganisms associated with bacterial vaginosis in 45.3% of the samples, Candida spp. in 23.8% of the samples, and Herpesviridae family viruses in 14.3% of the samples. In 45.2% of the samples, one to 14 genes of resistance to β-lactam and glycopeptide antibiotics were identified, while Tem (19.0%), Oxa-40-like (19.0%), Stx-M1 (14.3%), Ges (14.3%), Oxa-51-like (11.9%), and Van A/B (9.5%) were most frequently determined in the samples positive for resistance genes. Comparison between phenotypic susceptibility testing and genetic prediction for antibiotics resistance demonstrated that the specificity varied from 96.4 to 100%, and the sensitivity from 40.0 to 85.7%.

CONCLUSIONS: The use of molecular genetic diagnostic methods allows for the identification of clinically significant urogenital tract infections and the detection of markers of their resistance to β-lactam antibiotics and glycopeptides in the shortest possible time. The data obtained make it possible to optimize the initial antimicrobial chemotherapy.