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Odkażające działanie kwasu nadoctowego w stosunku do form wegetatywnych bakterii

100%

Krzywicka H.

Roczniki Państwowego Zakładu Higieny

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1970

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tom 21

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nr 4

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Przeżywalność Bacillus cereus w pożywkach imitujących środowisko żołądka człowieka

72%

Berthold-Pluta A., Pluta A., Molska I., Dolega E.

Medycyna Weterynaryjna

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2014

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tom 70

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nr 07

The aim of this study has been to determine the survival ability of B. cereus vegetative cells and spores in media simulating human stomach content after the ingestion of dairy or meat products contaminated with this species. The enterotoxic strain Bacillus cereus 228 isolated from raw milk was the subject of examination in this study. The gastric media (GM) simulating human stomach content used in the study were prepared by mixing: 4.80 g NaCl, 1.56 g NaHCO₃, 2.20 g KCl, 0.22 g CaCl₂ and 25 U/l pepsin solution with sterile UHT milk (0% and 3.2% fat content) or chicken broth in a 1:1 ratio. The pH values of the media were then adjusted and ranged from 2.0 to 4.5. Spore or vegetative cell suspensions of Bacillus cereus were added to GM to obtain the target initial populations of about 6.0 log CFU/ml. Incubation was carried out for 6 h at 37°C under aerobic conditions. The study revealed that B. cereus bacteria entering the human gastrointestinal tract have the ability to survive in the conditions prevailing in the human stomach environment. The survival ability in such conditions depends on the form of the ingested cells (vegetative cells or spores), on pH values, and on the kind of food with which they enter the gastrointestinal tract. B. cereus spores are highly resistant to the acidity of the human stomach environment both in the presence of chyme (at pH ~4.5) and in the absence of chyme (at pH ~2.0), regardless of the kind of food the spores were ingested with. On the other hand, B. cereus vegetative cells show diversified resistance to the conditions in the human stomach environment, depending on the pH (the quantity of chyme) and on what food the bacteria were ingested with. After inoculation with vegetative cells no survival of the vegetative cells was observed in 1 ml of each of the applied gastric media having pH 2.0 and 2.5 in the second hour of incubation. The survival rate of the vegetative cells at pH 4.5 was: 85.4% in GM-milk (3.2% fat content), 34.5% in GM-milk (0% fat content) and 4.5% in GM-chicken.

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Bakteriobójcze działanie aldehydu glutarowego w stosunku do form wegetatywnych bakterii

58%

Krzywicka H.

Roczniki Państwowego Zakładu Higieny

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1970

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tom 21

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nr 1

Ograniczanie wyników

2 Roczniki Państwowego Zakładu Higieny

1 Medycyna Weterynaryjna

2 Krzywicka H.

1 Berthold-Pluta A.

1 Dolega E.

1 Molska I.

1 Pluta A.

1 2014

2 1970

Odkażające działanie kwasu nadoctowego w stosunku do form wegetatywnych bakterii

Przeżywalność Bacillus cereus w pożywkach imitujących środowisko żołądka człowieka

Bakteriobójcze działanie aldehydu glutarowego w stosunku do form wegetatywnych bakterii