Bactérias do grupo do Bacillus cereus em leite e estudo enterotoxigênico das cepas isoladas
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Data
2002-12-03
Autores
Lago, Naiá Carla Marchi de Rezende [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O Bacillus cereus é um microrganismo ubíquo encontrado freqüentemente em produtos lácteos. As perdas econômicas e o risco que traz à saúde pública são alarmantes. Os objetivos deste trabalho foram pesquisar o Bacillus cereus em leite, verificar a sua capacidade enterotoxigênica e o risco que provoca à saúde pública e comparar diferentes técnicas utilizadas para detecção de toxinas. Para tal, foram analisadas 120 amostras de leite (30 de leite cru, 30 de leite pasteurizado, 30 de leite em pó e 30 de UAT). Para a pesquisa de enterotoxinas, foram utilizadas três técnicas. Encontraram-se contaminadas 15 (50,0%), 29 (96,7%), 22 (73,3%) e 4 (13,3%) amostras de leite cru, pasteurizado, em pó e UAT, respectivamente. Para a detecção de enterotoxinas pela técnica da alça ligada em coelhos, foram positivas, respectivamente, 1 (7,1%), 10 (35,7%) e 3 (13,6%) cepas das amostras de leite cru, pasteurizado e em pó. Para o teste de aumento de permeabilidade vascular dérmica, apresentaram-se enterotoxigênicas, respectivamente, 1 (7,1%), 1 (3,6%), 2 (9,1%) e 1 (4,0%) cepas isoladas de leite cru, pasteurizado, em pó e UAT. Para a detecção de enterotoxinas pela prova de aglutinação passiva em látex, apresentaram-se positivas 7 (63,6%), 4 (30,8%), 3 (33,3%) e 8 (80,0%) cepas isoladas, respectivamente, de leite cru, pasteurizado, em pó e UAT. Conclui-se que as amostras de leite analisadas, principalmente as amostras já processadas termicamente, deixam a desejar quanto a sua qualidade, colocando em risco a saúde dos consumidores. Conclui-se também que a técnica de aglutinação é a mais indicada para a detecção da enterotoxina produzida pelo Bacillus cereus.
Bacillus cereus is a ubiquitous microorganism frequently found in milk products. The economic losses and the damage to public health they cause are enormous. The objectives of this work were to search for Bacillus cereus in milk, their enterotoxigenic activity to estimate the risks the use of this product may produce and to compare different techniques used to detection of enterotoxins. For that, 120 samples of milk were examined (30 of raw milk, 30 of pasteurized milk, 30 of milk powder and 30 of UHT milk). To test the enterotoxigenicity, three techniques were used. Bacillus cereus was present in 15 (50,0%), 29 (96,7%), 22 (73,0%) and 4 (13,3%) samples of raw milk, pasteurized milk, milk powder and UHT milk, respectively. For the enterotoxigenicity detection using the assay in the rabbit ileal loop, 1 (7,1%), 10 (35,7%) and 3 (13,6%) strains from raw milk, pasteurized milk and milk powder were positive. For the enterotoxigenicity detection using the assay for vascular permeability activity, 1 (7,1%), 1 (3,6%), 2 (9,1%) and 1 (4,0%) strains from raw milk, pasteurized milk, milk powder and UHT milk were positive, respectively. Using the reversed passive latex agglutination, diarrheal toxin production was shown to be 7 (63,6%), 4 (30,8%), 3 (33,3%) and 8 (80,0%) strains respectively isolated from raw milk, pasteurized milk, milk powder, and UHT milk. It was concluded that the milk samples analyzed didn't present good quality and may put in risk the health of consumers of such products. We also concluded that the reversed passive latex agglutination is the best technique to determine the enterotoxins produced from Bacillus cereus.
Bacillus cereus is a ubiquitous microorganism frequently found in milk products. The economic losses and the damage to public health they cause are enormous. The objectives of this work were to search for Bacillus cereus in milk, their enterotoxigenic activity to estimate the risks the use of this product may produce and to compare different techniques used to detection of enterotoxins. For that, 120 samples of milk were examined (30 of raw milk, 30 of pasteurized milk, 30 of milk powder and 30 of UHT milk). To test the enterotoxigenicity, three techniques were used. Bacillus cereus was present in 15 (50,0%), 29 (96,7%), 22 (73,0%) and 4 (13,3%) samples of raw milk, pasteurized milk, milk powder and UHT milk, respectively. For the enterotoxigenicity detection using the assay in the rabbit ileal loop, 1 (7,1%), 10 (35,7%) and 3 (13,6%) strains from raw milk, pasteurized milk and milk powder were positive. For the enterotoxigenicity detection using the assay for vascular permeability activity, 1 (7,1%), 1 (3,6%), 2 (9,1%) and 1 (4,0%) strains from raw milk, pasteurized milk, milk powder and UHT milk were positive, respectively. Using the reversed passive latex agglutination, diarrheal toxin production was shown to be 7 (63,6%), 4 (30,8%), 3 (33,3%) and 8 (80,0%) strains respectively isolated from raw milk, pasteurized milk, milk powder, and UHT milk. It was concluded that the milk samples analyzed didn't present good quality and may put in risk the health of consumers of such products. We also concluded that the reversed passive latex agglutination is the best technique to determine the enterotoxins produced from Bacillus cereus.
Descrição
Palavras-chave
Bacillus cereus, Milk, Leite - Bacteriologia, Enterotoxinas, Bactérias
Como citar
LAGO, Naiá Carla Marchi de Rezende. Bactérias do grupo do Bacillus cereus em leite e estudo enterotoxigênico das cepas isoladas. 2002. xii, 70 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2002.