Enumeration of <i>Clostridium botulinum</i> spores in meats by a pour-plate procedure

Hauschild, A. H. W.; Hilsheimer, R.

doi:10.1139/m77-122

Cited by 31 publications

(11 citation statements)

References 2 publications

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“…botulinum, as lysozyme was probably not present in many media used to recover heat-treated spores. If an egg-yolk medium is used, however, results similar to those we have obtained on PYGS + lysozyme would be expected (Hauschild and Hilsheimer 1977;Smelt 1980;Peck et al 1992a). The significance of these D-values is influenced by the proportion of spores that are permeable to lysozyme, and the observation that 20% of heated spores of strain Foster B96 were permeable to lysozyme tends to increase the importance of D-values estimated on lysozyme-containing medium.…”

Section: Discussionsupporting

confidence: 78%

Heat-resistance of spores of non-proteolytic Clostridium botulinum estimated on medium containing lysozyme

Peck

Fairbairn

Lund

1993

Lett Appl Microbiol

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Heat treatment of spores of non‐proteolytic strains of Clostridium botulinum at 75–90°C, and enumeration of survivors on a nutrient medium containing lysozyme gave biphasic survival curves. A majority of spores were inactivated rapidly by heating, and the apparent heat‐resistance of these spores was similar to that observed by enumeration on medium without lysozyme. A minority of spores showed much greater heat‐resistance, due to the fact that the spore coat was permeable to lysozyme, which diffused into the spore from the medium and replaced the heat‐inactivated germination system. The proportion of heated spores permeable to lysozyme was between 0.2 and 1.4% for spores of strains 17B (type B) and Beluga (type E), but was about 20% for spores of strain Foster B96 (type E). After treatment of heated spores with alkaline thioglycolate, all were permeable to lysozyme. D‐values for heated spores that were permeable to lysozyme (naturally and after treatment with thioglycolate) were: for strain 17B, D85°C, 100 min; D90°C, 18.7 min; D95°C, 4.4 min; for strain Beluga, D85°C, 46 min; D90°C, 11.8 min; D95°C, 2.8 min. The z‐values for these spores of strains 17B and Beluga were 7.6°C and 8.3°C.

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Section: Discussionsupporting

confidence: 78%

Heat-resistance of spores of non-proteolytic Clostridium botulinum estimated on medium containing lysozyme

Peck

Fairbairn

Lund

1993

Lett Appl Microbiol

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“…It has been shown previously that the addition of HEWL (Sebald and Ionesco 1972;Alderton et al 1974;Scott and (Peck and Stringer 1996), horse blood (Lund and Peck 1994) and egg yolk emulsion (Hauschild and Hilscheimer 1977 ;Smelt 1980;Peck et al 1992a;Lund and Peck 1994) to the plating medium each increased the measured heat resistance of spores of non-proteolytic C1. hotulinum.…”

Section: Discussionmentioning

confidence: 93%

Vegetable juice aids the recovery of heated spores of non-proteolytic Clostridium botulinum

Stringer¹,

Peck

1996

Lett Appl Microbiol

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Heating spores of non‐proteolytic Clostridium botulinum at 85d̀C for 2 min followed by plating on a standard laboratory medium reduced the count of viable spores by a factor of greater than 104. A similar result was obtained when the plating medium was supplemented with juice from courgette, carrot or mung bean sprout. When plating was on media supplemented with hen egg white lysozyme or juice from turnip, swede, flat bean, cabbage or potato, heating at 85d̀C for 10 min did not reduce the viable count by a factor of 104. Thus these vegetable juices increased the measured heat resistance of spores of non‐proteolytic Cl. botulinum. These findings are relevant to the safety of minimally processed (e.g. sous‐vide) foods.

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“…Spore inocula were prepared as described by Durban et al (1974) and enumerated by a pour plate method (Hauschild and Hilsheimer 1977).…”

Section: Test Cultures and Spore Inoculamentioning

confidence: 99%

“…Samples inoculated with type E spore preparations were not heat treated and were incubated at 30°C for 48 h. One ml of each spore dilution was checked for germination by inoculating CMM. Diluted spore preparations were simultaneously enumerated by a pour plate method (Hauschild and Hilsheimer 1977). Negative controls included a sterile CMM without added sample or inoculum and CMM with sample only.…”

Section: Inoculation Of Samplesmentioning

confidence: 99%

Polymerase chain reaction for detection of Clostridium botulinum types A, B and E in food, soil and infant faeces

Szabo

Pemberton

Gibson

et al. 1994

Journal of Applied Bacteriology

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The application of the polymerase chain reaction (PCR) for detection of Clostridium botulinum types A, B and E in foods, environmental and clinical samples was evaluated and compared to the mouse bioassay. Samples inoculated with 10, 100 and 1000 spores of Cl. botulinum types A and B included pasteurized milk, UHT milk, infant formula, infant faeces, meat juice, canned tuna, mushrooms, blood sausage and soil. Clostridium botulinum type E spores were inoculated into fish eggs, canned tuna, picked herring, raw fish and soil at similar levels. Spores were added to 2.5 g of each sample with the exception of soil which was inoculated in 10 g samples. The presence of Cl. botulinum in sample enrichments was determined by both PCR and the bioassay. An overall correlation of 95.6% was observed between PCR results and the mouse bioassay. Of the total of 114 samples tested there was disparity between the mouse bioassay and the PCR in three samples of soil inoculated with 100 type A or E spores and 10 type B spores per 10 g, respectively, and two samples of infant faeces inoculated with 10 type A or B spores per 2.5 g. All of these samples gave negative animal results and positive PCR results.

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Enumeration of Clostridium botulinum spores in meats by a pour-plate procedure

Cited by 31 publications

References 2 publications

Heat-resistance of spores of non-proteolytic Clostridium botulinum estimated on medium containing lysozyme

Heat-resistance of spores of non-proteolytic Clostridium botulinum estimated on medium containing lysozyme

Vegetable juice aids the recovery of heated spores of non-proteolytic Clostridium botulinum

Polymerase chain reaction for detection of Clostridium botulinum types A, B and E in food, soil and infant faeces

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