Species composition and antibiotic resistance of lactobacillus in infants

Objective: To study species composition and antibiotic resistance of indigenous bacteria from Lactobacillus genus in infants.

Methods: Twenty-six strains of lactobacilli isolated from feces of infants living in Kazan. Species membership of lactobacilli was determined using PCR with primers for identification of 7 species of lactobacilli: L. acidophilus, L. plantarum, L. rhamnosus, L. delbrueckii, L. casei, L. paracasei, and L. zeae. Susceptibility to antibiotics was determined by indicator paper discs method. RESULTS. In breastfed infants L. fermentum and L. rhamnosus dominated, whereas in artificially fed infants colonization with L. casei and L. paracasei was characteristic. L.acidophilus, L. plantarum, and L. zeae were not detected in infants. In 6 cases isolates could be identified only to genus characteristic. Lactobacilli were polyresistant and had from 8 to 15 markers of resistance. All strains were resistant to ciprofloxacin, co-trimoxazole, ceftriaxone, nitroxoline, metronidazole, furazolidone, and 95% of strains were resistant to vancomycin. In 60-70% of cases lactobacilli were susceptible to penicillin, linezolid, erythromycin and lyncomycin.

Conclusions: Regional features of species composition and antibiotic resistance of lactobacilli in infants depending on type of feeding were revealed.