Production biomolecule with inhibitory activity against Gram-negative bacteria isolated from faeces of broilers and swine

The aim of this study was to investigate the potential of lactic acid bacteria, bacilli and yeasts isolates to produce antimicrobial substances, especially against Gram-negative bacteria isolated from the animal faeces, searching for a new alternative to control the enteritis diseases in animal health. Evaluations were performed by microdilution in broth using crude extract obtained from the cultivation of 272 strains against Escherichia coli, S. Typhimurium, S. Enteritidis and Pseudomonas aeruginosa. Thirty-five lactic acid bacteria presented some antimicrobial action. One Lactobacillus isolate, named FLPB-1, was selected to studies the kinetics of the production. An important increase in the production was obtained when the producer strain had cell-to-cell contact with a Gram-positive inducer culture. Maximal production of antimicrobial compounds was obtained in the beginning of stationary phase and the addition of urea in the medium increased the inhibition rate.

Adesinas, hemolisinas e hemaglutininas em amostras uropatogênicas de Escherichia coli / Adhesins, hemolysins and hemagglutinins in Escherichia coli urophatogenic samples

Foram analisadas 30 amostras de Escherichia coli uropatogênicas, isoladas de pacientes do Hospital de Clínicas da Universidade Federal do Paraná, com sintomas de infecçäo urinária. Nessas amostras foram pesquisados três fatores de virulência: expressäo de hemaglutininas, expressäo de hemolisinas e adesäo celular a células epiteliais. A pesquisa de hemaglutininas revelou a seguinte expressäo fenotípica entre os isolados clínicos: 40 porcento aglutinaram eritrócitos de cobaia na ausência de D-manose (amostras manose-sensíveis - MS); 13,3 porcento aglutinaram eritrócitos humanos na presença de D-manose (amostras manose-resistentes - MR); 30 porcento das amostras apresentaram os dois padröes de hemaglutinaçäo (amostras MR MS) e 16,6 porcento das amostras näo expressaram as hemaglutininas pesquisadas. A produçäo de hemolisina ocorreu em 26,6 porcento das amostras e sempre foi acompanhada da expressäo de hemaglutininas MS. Todas as amostras com fenótipo MR MS aderiram à linhagem celular, enquanto que amostras MS e amostras MR aderiram em menor grau, e as amostras näo hemaglutinantes, praticamente, näo aderiram. Esses resultados sugerem uma possível relaçäo entre hemaglutinaçäo e virulência bacteriana.