Microbiological monitoring of antibiotic resistance of strains of Streptococcus agalactiae among pregnant women

Abstract

Group B Streptococcus (GBS) is the causative agent in 2–7% of all urinary tract infections (UTI), including asymptomatic bacteriuria (AB), cystitis, and pyelonephritis. We used the bacteriological quantitative method of sowing urine samples of pregnant women on Columbia agar with 5% lamb blood), Strepto B chromogenic agar and Todd Hewitt broth, identification of GBS strains with determination of sensitivity to bacitracin, hippurate hydrolysis test and CAMP test. Susceptibility to antimicrobial drugs was determined by the disk-diffusion method according to recommendations of the European Committee on Antimicrobial Susceptibility Testing. For the period of 2021, out of 3,356 urine samples of pregnant women, there were 149 samples of the investigated biomaterial with a positive result for GBS (resultancy – 4.4%). It was established that among the studied contingent, 41 strains of GBS were isolated in the first trimester of pregnancy (27.5%), in the second trimester – 59 strains (39.5%), in the third trimester – 49 strains (33.0%). It is established that out of the 149 strains of GBS, 38 strains (25.0%) were resistant to norfloxacin, 45 strains (30.0%) to erythromycin, 41 strains (28.0%) to clindamycin,125 strains (84.0%) to tetracycline, 20 strains (13.0%) to levofloxacin, 3 strains (2.0%) to nitrofurantoin. All strains of Streptococcus agalactiae were found to be sensitive to benzylpenicillin. The number of resistant strains of SGB identified from the urine of pregnant women was 47 strains. All resistant strains were resistant to at least three groups of antibacterial drugs, except beta-lactams. The results of the scientific research will allow us to obtain dynamic data on the antibiotic resistance of GBS strains in order to study the rate of development of antibiotic sensitivity of this microorganism. In the future, the research data can be used by scientists when reviewing protocols for the treatment of urinary tract infections in pregnant women.