Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/200137
Type: Artigo de periódico
Title: Effect Of High Hydrostatic Pressure On Aeromonas Hydrophila Ah 191 Growth In Milk.
Author: Durães-Carvalho, Ricardo
Souza, Ancelmo R
Martins, Luciano M
Sprogis, Adriane C S
Bispo, Jose A C
Bonafe, Carlos F S
Yano, Tomomasa
Abstract: Exposure to high pressure is an efficient method of bacterial inactivation that is particularly important for reducing the microbial load present in foods. In this study, we examined the high pressure inactivation of Aeromonas hydrophila AH 191, a virulent strain that produces aerolysin, a cytotoxic, enterotoxic, and hemolytic toxin. High pressure treatment (250 MPa for 30 min at 25 °C in 0.1 M PBS, pH 7.4) of A. hydrophila grown in milk reduced bacterial viability by at least 9 orders of magnitude. Under these conditions, the enterotoxic, hemolytic, and cytotoxic activities of A. hydrophila culture supernatants were unaltered. These results indicate the need for caution in the use of high pressure for food processing since although truly toxigenic bacteria may be inactivated, their toxins may not be, thus posing a risk to human health. At higher pressure (350 MPa) the inactivation of bacteria was much more effective. Scanning electron microscopy showed a significant decrease in the number of bacteria after higher pressurization (350 MPa for 1 h) and transmission electron microscopy showed irregular shaped bacteria, suggestive of important cell wall and membrane damage, and cytoplasm condensation. High pressure inactivates Aeromonas hydrophila efficiently but is enhanced when combined with moderate temperature (40 °C). The biological activities of toxins from this bacterium are unaltered under these conditions.
Subject: Aeromonas Hydrophila
Animals
Bacterial Toxins
Caco-2 Cells
Cercopithecus Aethiops
Enterotoxins
Food Contamination
Food Handling
Food Microbiology
Humans
Hydrogen-ion Concentration
Hydrostatic Pressure
Microscopy, Electron, Scanning
Microscopy, Electron, Transmission
Milk
Pore Forming Cytotoxic Proteins
Temperature
Vero Cells
Rights: fechado
Identifier DOI: 10.1111/j.1750-3841.2012.02819.x
Address: http://www.ncbi.nlm.nih.gov/pubmed/22860590
Date Issue: 2012
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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