evaluation of antimicrobial susceptibility of streptococcus agalactiae isolates from patients with urinary tract infection (uti) symptoms

background: streptococcus agalactiae, also known as group b streptococcus (gbs) is a commensal organism in the urogenital tract and rectum in approximately 25% of the healthy adult female population. the bacterium is the leading cause of bacterial meningitis, pneumonia, and sepsis in human infants. materials and methods: our study was performed over a three - month period from april to june 2014. midstream specimens of urine were collected from outpatients suspected of having a bacterial urinary tract infection, which had not received any antibiotics. group b streptococci isolates were confirmed by typical colony morphology and identified by differential tests. antibiotic susceptibility testing was carried out by disk diffusion method on mueller hinton agar (merck, germany) based on (clsi) guidelines 2012. results: gbs strains were isolated from 264 (21.1%) cases (out of 1249 positive bacterial urine cultures). the higher prevalence was recorded in the 15-44 and 45-64 age groups. antibiotic susceptibility tests revealed that vancomycin, penicillin, and linezolid had the lowest, and tetracycline had the highest resistance rate. conclusion: in conclusion, the results of the present study confirm the universal susceptibility of gbs strains to the penicillin family and assert the use of penicillin or ampicillin as the first drug of choice for treatment and prophylaxis against gbs infections. however, it is important to perform antibiotic susceptibility testing whenever penicillin could not be prescribed.