Safety characterization and antimicrobial properties of kefir-isolated Lactobacillus kefiri

CARASI P; DÍAZ M; RACEDO SM; DE ANTONI GL; URDACI MC; SERRADELL MA

JOURNAL OF BIOMEDICINE AND BIOTECHNOLOGY

HINDAWI PUBLISHING CORPORATION

Lugar: New York; Año: 2014

1110-7243

Lactobacilli are generally regarded as safe however certain strains have been associated with cases of infection. Our workgroup has already characterized many probiotic properties of Lactobacillus kefiri strains, but no parameter regarding the safety of L. kefiri consumption was ever evaluated. Since beneficial properties and harmful characteristic are dependent on the strain, safety aspects and antimicrobial activity of L. kefiri strains were studied in this work. None of the L. kefiri strains tested caused α-or β-hemolysis. All the strains were susceptible to tetracycline, clindamycin, streptomycin, ampicillin, erythromycin, kanamycin and gentamicin, meanwhile two strains (CIDCA 8321 and 8345) were resistant to chloramphenicol. On the other hand, all L. kefiri strains were able to inhibit both Gram positive and Gram negative pathogens; however the strains CIDCA 8321, 8348 and 83111 showed higher inhibition capabilities. Regarding the in vitro results, CIDCA 8348 was selected to perform in vivo studies. Mice treated daily with an oral dosis of 108 CFU during 21 days showed no signs of pain, lethargy, dehydration or diarrhea during treatment, and the histological studies were consistent with those findings. Moreover, no translocation of microorganisms to blood, spleen or liver was observed. Regarding these findings, L. kefiri CIDCA 8348 is a microorganism isolated from a dairy product with a great potential as probiotic for human or animal use.