Parâmetros de segurança e funcionalidade de bactérias bífidas isoladas de recém-nascidos, com indicação de uso como probiótico em bancos de leite humano

• Autor(a) principal: Cunha, Luciana Rodrigues da
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2957
• topic: Susceptibilidade antimicrobiana; Atividade antagonista; Translocação bacteriana; Toxicidade oral crônica; Probiótico; Antimicrobial susceptibility; Antagonism activity; Bacterial translocation; Oral chronic toxicity; Probiotics; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS

The objective of this study was to evaluate some parameters of security and functionality currently recommended for validation of probiotics. The parameters evaluated were antimicrobial susceptibility, antagonism to the growth of pathogens, oral chronic toxicity and bacterial translocation of new lineages of Bifidobacterium breve isolated from newborn, with potential of use as probiotics in human milk banks. The experiments were divided in three parts. In the first one, the susceptibility of 31 lineages of Bifidobacterium breve to the most common antimicrobials (14) used in UTIneonatal from Brazilian institutions was evaluated. In the second part, the antagonism to the growth of lineages of Clostridium difficile, Salmonella typhimurium, Escherichia coli, Listeria monocytogenes and Staphylococcus aureus was evaluated using the "spot" technique and plate diffusion. To exclude the effect of organic acid inhibition, the spot test was also performed in buffered sodium bicarbonate medium. Based in the results found in the test of antibiotics sensitivity and in those of resistance to bile salts and gastric juice from previous studies, seven lineages were selected to compose the pool of probiotics that was used for verification of the oral chronic toxicity and bacterial translocation, in the third phase of the experiment, in which it was used for each replication 16 wearing Wistar rats with 21-23 days of life, were divided in 4 groups: Basal, Control, LP (pasteurized human milk) and LPB (pasteurized human milk containing bifid bacterium). The four animals that composed the basal group were sacrificed in the first day of the experiment (T0) while the others were fed with different diets during 21 days and sacrificed later. Liver, kidneys, heart, and spleen were removed, weighed and tested for oral chronic toxicity and bacterial translocation. The experiment was conducted in three repetitions. It was found that the 31 lineages of Bifidobacterium breve were resistant to antimicrobial ciprofloxacin, amicacin and gentamicin, among the 14 antibiotics evaluated. For the other antimicrobials, sensitivity varied from 2% (sulfonamide) to 100% (vancomycin, amoxicillin, ampicillin and penicillin). These same isolated varied in the antagonistic activity on the growth of the different pathogens evaluated by the "spot" method. This inhibition was lineage-dependent and not only promoted by organic acids, as it was not totally reverted in the buffered medium. The supernatant free of bifid bacteria cells did not promote inhibition of the pathogens evaluated. It was verified that the selected lineages of Bifidobacterium breve (UFVCC 1083, 1091, 1099, 1103, 1105, 1108 and 1111) did not promote adverse effect in the animal health. Similarly, they did not induce oral chronic toxicity or translocation of bacteria of the gastrointestinal tract to the liver, kidneys, heart and spleen after 21 days of experimentation.