title: Safety characterization and antimicrobial properties of kefir-isolated Lactobacillus kefiri.
abstract: Lactobacilli are generally regarded as safe; however, certain strains have been associated with cases of infection. Our workgroup has already assessed many functional properties of Lactobacillus kefiri, but parameters regarding safety must be studied before calling them probiotics. In this work, safety aspects and antimicrobial activity of L. kefiri strains were studied. 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 were resistant to chloramphenicol. On the other hand, all L. kefiri strains were able to inhibit both Gram(+) and Gram(-) pathogens. Regarding the in vitro results, L. kefiri CIDCA 8348 was selected to perform in vivo studies. Mice treated daily with an oral dose of 10(8) CFU during 21 days showed no signs of pain, lethargy, dehydration, or diarrhea, and the histological studies were consistent with those findings. Moreover, no differences in proinflammatory cytokines secretion were observed between treated and control mice. 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.
authors: Cátedra de Microbiología, Departamento de Ciencias Biológicas, de La Plata, 47 y 115 s/n, CP, 1900 La Plata, Argentina.
authors: Paula
authors: P
authors: Carasi
authors: Cátedra de Microbiología, Departamento de Ciencias Biológicas, de La Plata, 47 y 115 s/n, CP, 1900 La Plata, Argentina.
authors: Mariángeles
authors: 0000-0003-2343-5915
authors: M
authors: Díaz
authors: Laboratoire de Microbiologie et Biochimie Appliquée (LBMA), Université de Bordeaux, UMR 5248, Bordeaux Sciences Agro, 1 Cours du Général de Gaulle, 33175 Gradignan, France.
authors: Silvia M
authors: SM
authors: Racedo
authors: Cátedra de Microbiología, Departamento de Ciencias Biológicas, de La Plata, 47 y 115 s/n, CP, 1900 La Plata, Argentina.
authors: Graciela
authors: G
authors: De Antoni
authors: Laboratoire de Microbiologie et Biochimie Appliquée (LBMA), Université de Bordeaux, UMR 5248, Bordeaux Sciences Agro, 1 Cours du Général de Gaulle, 33175 Gradignan, France.
authors: María C
authors: MC
authors: Urdaci
authors: Cátedra de Microbiología, Departamento de Ciencias Biológicas, de La Plata, 47 y 115 s/n, CP, 1900 La Plata, Argentina.
authors: María de los Angeles
authors: 0000-0002-3960-080X
authors: Mde L
authors: Serradell
mesh_terms: D000818:Animals; D043302:Cultured Milk Products / Q000009:adverse effects* / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D007778:Lactobacillus / Q000378:metabolism* / Q000472:pathogenicity; D051379:Mice; D008826:Microbial Sensitivity Tests; D019936:Probiotics / Q000008:administration & dosage* / Q000009:adverse effects