scholarly journals Influence of sodium chloride on the beta-glucuronidase activity of Clostridium perfringens and Escherichia coli

2000 ◽  
Vol 31 (3) ◽  
pp. 255-258 ◽  
Author(s):  
T. Fujisawa ◽  
K. Aikawa ◽  
T. Takahashi ◽  
S. Yamai
Meat Science ◽  
2021 ◽  
pp. 108557
Author(s):  
Vijay K. Juneja ◽  
Marangeli Osoria ◽  
Anuj S. Purohit ◽  
Chase E. Golden ◽  
Abhinav Mishra ◽  
...  

2002 ◽  
Vol 184 (7) ◽  
pp. 2034-2038 ◽  
Author(s):  
Milena M. Awad ◽  
Julian I. Rood

ABSTRACT The pathogenesis of Clostridium perfringens-mediated gas gangrene or clostridial myonecrosis involves the extracellular toxins alpha-toxin and perfringolysin O. Previous studies (T. Shimizu, A. Okabe, J. Minami, and H. Hayashi, Infect. Immun. 59:137-142, 1991) carried out with Escherichia coli suggested that the perfringolysin O structural gene, pfoA, was positively regulated by the product of the upstream pfoR gene. In an attempt to confirm this hypothesis in C. perfringens, a pfoR-pfoA deletion mutant was complemented with isogenic pfoA+ shuttle plasmids that varied only in their ability to encode an intact pfoR gene. No difference in the ability to produce perfringolysin O was observed for C. perfringens strains carrying these plasmids. In addition, chromosomal pfoR mutants were constructed by homologous recombination in C. perfringens. Again no difference in perfringolysin O activity was observed. Since it was not possible to alter perfringolysin O expression by mutation of pfoR, it was concluded that the pfoR gene product is unlikely to have a role in the regulation of pfoA expression in C. perfringens.


Author(s):  
José Roberto Guimarães ◽  
Regiane Aparecida Guadagnini ◽  
Regina Maura Bueno Franco ◽  
Luciana Urbano dos Santos

AbstractThis study evaluated the effectiveness of H


2018 ◽  
Vol 23 (5) ◽  
pp. 987-994
Author(s):  
Carlos Raphael Pedroso ◽  
Jeanette Beber de Souza ◽  
Thaís Kovalski ◽  
Carlos Magno de Sousa Vidal ◽  
Kelly Geronazzo Martins

RESUMO Esta pesquisa teve como objetivo avaliar o desempenho da radiação ultravioleta (UV) para a desinfecção de efluente final de estação de tratamento de esgoto (ETE) sanitário municipal, em escala de bancada de laboratório e operação em batelada. Foram analisadas as interferências dos parâmetros operacionais tempo de exposição (s) à radiação e altura de lâmina líquida (cm) do efluente no reator UV. A eficiência do processo de desinfecção foi avaliada empregando os microrganismos indicadores Clostridium perfringens (C. perfringens), colifagos, Escherichia coli (E. coli) e coliformes totais (CT). Após a desinfecção, foram avaliados os fenômenos de recuperação microbiológica fotorreativação e recuperação no escuro para E. coli e CT. Os resultados indicaram efetiva inativação dos microrganismos indicadores à radiação UV no decorrer do tempo de exposição, o que foi comprovado estatisticamente pela ANOVA de medidas repetidas. C. perfringens foi o microrganismo que apresentou a maior resistência à inativação. Nos ensaios de recuperação microbiológica, ambos os mecanismos foram considerados insignificantes, o que foi comprovado estatisticamente pelos testes t de Student (dados paramétricos) e Wilcoxon (dados não paramétricos). Em todas as análises, o nível de significância foi de 5%.


1994 ◽  
Vol 57 (4) ◽  
pp. 337-340 ◽  
Author(s):  
AJIBOLA O. FAPOHUNDA ◽  
KENNETH W. MCMILLIN ◽  
DOUGLAS L. MARSHALL ◽  
W. M. WAITES

Isolates of Escherichia coli and Clostridium perfringens from beef and Aeromonas hydrophila from fish were examined for their ability to survive and grow as cross-contaminates on nonnative tissues at simulated ambient (35°C) and aging/conditioning (15°C) temperatures of handling and retailing found in the tropics. Growth of all isolates over a 10-h period was greater (P < 0.05) on their native tissues at both temperatures. The aging/conditioning temperature effectively limited growth of E. coli and A. hydrophila to less than l-logl0 CFU/g and prevented growth of C. perfringens on beef and fish samples. All three isolates demonstrated characteristic mesophilic growth response on both tissues at 35°C during the 10-h retail period. The study suggests that two muscle food products could be jointly handled to efficiently use available storage/haulage capacity in tropical countries. Potential savings in space, labor and energy would be made if cross-contamination between the two products is minimized by available packaging and sanitizing technologies.


2014 ◽  
Vol 59 (No. 8) ◽  
pp. 374-380
Author(s):  
E. Skřivanová ◽  
Š. Pražáková ◽  
O. Benada ◽  
P. Hovorková ◽  
MarounekM

The sucrose monoesters of capric and lauric acid were tested for their antibacterial activity towards two foodborne enteropathogenic bacteria &ndash; Escherichia coli (CCM 3954 &ndash; serotype O6 and E22 &ndash; serotype O103) and Clostridium perfringens (CNCTC 5459 and CIP 105178). Antibacterial activity was evaluated by the plating technique. Sucrose monocaprate significantly decreased the number of viable cells of E. coli at all tested concentrations (0.1&ndash;5 mg/ml). The overnight incubation of C. perfringens with the sucrose ester of lauric acid at 0.1&ndash;5 mg/ml reduced the number of viable cells below the detection limit (2 log<sub>10</sub> CFU/ml). Incubating E. coli CCM 3954 and C. perfringens CNCTC 5459 with monoesters (0.1 and 2 mg/ml) did not influence the K<sup>+</sup> permeability of the cytoplasmic membrane in cells during a 2.5-minute treatment. A 30-minute incubation of E. coli CCM 3954 and C. perfringens CNCTC 5459 with esters (0.1 and 2 mg/ml) revealed damage to cytoplasmic structures, as observed by transmission electron microscopy. &nbsp;


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