Serotyping and Antibiotic Susceptibility of Invasive Streptococcus agalactiae in Egyptian Patients with or without Diabetes Mellitus

Abstract

Streptococcus agalactiae serotype distribution and its antibiotic susceptibility affect disease prevention strategies, but the serotype distribution varies among patient groups. The objectives of this study were to establish the group B Streptococcus (GBS) serotype distribution in patients from Egypt and to assess antibiotic sensitivity of invasive GBS isolates. A total of 490 patients participated in this multicenter study; 160 had urinary tract infection, 115 complained of diabetic foot ulcers, 125 men had genital tract infections, and 30 women females had genital tract infections. Others had bronchopneumonia, otitis media, synovitis, or meningitis. Serotyping of the isolated GBS was performed at the CDC in the United States. Antibiotic sensitivity patterns were determined using the disk diffusion method. In men, the most common serotypes were II, III, and V, whereas types Ia, II, III, and V were isolated from women. Macrolides (erythromycin) resistance occurred in 4.1% of the isolates; 10.2% were resistant to both clindamycin and inducible resistance of macrolides, lincomycin, and streptogramin; 17.3% were resistant to quinolones; and 95.9% were resistant to tetracyclines. GBS primarily infected the urinary tract, skin, soft tissue, and genital tract in both genders. Isolates were sensitive to beta-lactam drugs, vancomycin, and linezolid; 14.0% were resistant to macrolides with or without clindamycin. Only 6.0% of the strains were sensitive to tetracyclines. Although GBS causes invasive infections in Egyptian adults, it rarely causes neonatal meningitis or sepsis. Future studies should determine whether GBS isolates are transmitted sexually, by performing a follow-up study of the partner of the infected patient.