Chemical, Biological, and Physical Methods
275
two methods were highly comparable, but those by flow cytometry were obtained in ca. 1 hour.
73 A
flow cytometric method for assessing the Gram reaction of bacteria in raw milk was developed by
using two fluorescent stains one of which stains only Gram-positive cells while the other stains both
Gram positives and Gram negatives. With seven Gram positives and five Gram negatives, the method
correctly recognized the Gram reactions of 99%.
81
BioSys Instrument
The BioSys-32 instrument makes automatic and computer-analyzed changes in the color of reaction
vials as organisms grow in specified culture media that contain a substrate that changes color in
proportion to increases in numbers of cells. It was used to simultaneously detect Salmonella and Listeria
spp. in 70 naturally contaminated foods by the decrease in light transmission upon the production of
H 2 S by Salmonella spp.
158 By this method, 10–50 salmonellae or listeriae/25 g could be detected in
24 hours with an additional 6 hours needed for PCR confirmation of results. The BioSys instrument
has been used successfully to measure amino acid decarboxylation in enteric bacteria,
188 Listeria spp.
in environmental swabs and sponges,
62 the effects of citrate and lactate on raw meat biota,
189 and the
antilisterial activity of lactate and diacetate in ready-to-eat meats.
137
REFERENCES
1. Adcock, P.W., and C.P. Saint. 2001. Rapid confirmation of Clostridium perfringens by using chromogenic and fluorogenic
substrates. Appl. Environ. Microbiol. 67:4382–4384.
2. Ahmed, R., P. Sankar-Mistry, S. Jackson, H.W. Ackermann, and S.S. Kasatiya. 1995. Bacillus cereus phage typing as an
epidemiological tool in outbreaks of food poisoning. J. Clin. Microbiol. 33:636–640.
3. Areson, P.W.D., S.E. Charm, and B.L. Wong. 1980. Determination of staphylococcal enterotoxins A and B in various
food extracts, using staphylococcal cells containing protein. J. Food Sci. 45:400–401.
4. Audurier, A., and C. Martin. 1989. Phage typing of Listeria monocytogenes. Int. J. Food Microbiol. 8:251–257.
5. Audurier, A., R. Chatelain, F. Chalons, and M. Pi´ echaud. 1979. Lysotypie de 823 souches de Listeria monocytogenes
isol´ ees en France de 1958 `
a 1978. Ann. Microbiol. (Inst. Pasteur). 130B:179–189.
6. Autio, T., S. Hielm, M. Miettinen, A.-M. Sj¨ oberg, K. Aarnisalo, J. Bj¨ orkroth, T. Mattila-Sandholm, and H. Korkeala.
1999. Sources of Listeria monocytogenes contamination in a cold-smoked rainbow trout processing plant detected by
pulsed-field gel electrophoresis typing. Appl. Environ. Microbiol. 65:150–155.
7. Ayres, J.C. 1967. Use of fluorescent antibody for the rapid detection of enteric organisms in egg, poultry and meat products.
Food Technol. 21:631–640.
8. Babacan, S., P. Pivarnik, S. Letcher, and A. Rand. 2002. Piezoelectric flow injection analysis biosensor for the detection
of Salmonella Typhimurium. J. Food Sci. 67:314–320.
9. Bachrach, U., and Z. Bachrach. 1974. Radiometric method for the detection of coliform organisms in water. Appl.
Microbiol. 28:169–171.
10. Baez, L.A., and V.K. Juneja. 1995. Nonradioactive colony hybridization assay for detection and enumeration of enterotoxigenic Clostridium perfringens in raw beef. Appl. Environ. Microbiol. 61:807–810.
11. Bastish, V.K., H. Chander, and G. Ranganathan. 1984. Incidence of enterococcal thermonuclease in milk and milk products.
J. Food Sci. 49:1610–1611, 1615.
12. Bautista, D.A., J.P. Vaillancourt, R.A. Clarke, S. Renwick, and M.W. Griffiths. 1995. Rapid assessment of the microbiological quality of poultry carcasses using ATP bioluminescence. J. Food Protect. 58:551–554.
13. Beezer, A.E., D. Newell, and H.J.V. Tyrrell. 1976. Application of flow microcalorimetry to analytical problems: The
preparation, storage and assay of frozen inocula of Saccharomyces cerevisiae. J. Appl. Bacteriol. 41:197–207.
14. Beezer, A.E., D. Newell, and H.J.V. Tyrrell. 1978. Characterisation and metabolic studies of Saccharomyces cerevisiae
and Kluyveromyces fragilis by flow microcalorimetry. Antonie Van Leeuwenhoek 45:55–63.
275
two methods were highly comparable, but those by flow cytometry were obtained in ca. 1 hour.
73 A
flow cytometric method for assessing the Gram reaction of bacteria in raw milk was developed by
using two fluorescent stains one of which stains only Gram-positive cells while the other stains both
Gram positives and Gram negatives. With seven Gram positives and five Gram negatives, the method
correctly recognized the Gram reactions of 99%.
81
BioSys Instrument
The BioSys-32 instrument makes automatic and computer-analyzed changes in the color of reaction
vials as organisms grow in specified culture media that contain a substrate that changes color in
proportion to increases in numbers of cells. It was used to simultaneously detect Salmonella and Listeria
spp. in 70 naturally contaminated foods by the decrease in light transmission upon the production of
H 2 S by Salmonella spp.
158 By this method, 10–50 salmonellae or listeriae/25 g could be detected in
24 hours with an additional 6 hours needed for PCR confirmation of results. The BioSys instrument
has been used successfully to measure amino acid decarboxylation in enteric bacteria,
188 Listeria spp.
in environmental swabs and sponges,
62 the effects of citrate and lactate on raw meat biota,
189 and the
antilisterial activity of lactate and diacetate in ready-to-eat meats.
137
REFERENCES
1. Adcock, P.W., and C.P. Saint. 2001. Rapid confirmation of Clostridium perfringens by using chromogenic and fluorogenic
substrates. Appl. Environ. Microbiol. 67:4382–4384.
2. Ahmed, R., P. Sankar-Mistry, S. Jackson, H.W. Ackermann, and S.S. Kasatiya. 1995. Bacillus cereus phage typing as an
epidemiological tool in outbreaks of food poisoning. J. Clin. Microbiol. 33:636–640.
3. Areson, P.W.D., S.E. Charm, and B.L. Wong. 1980. Determination of staphylococcal enterotoxins A and B in various
food extracts, using staphylococcal cells containing protein. J. Food Sci. 45:400–401.
4. Audurier, A., and C. Martin. 1989. Phage typing of Listeria monocytogenes. Int. J. Food Microbiol. 8:251–257.
5. Audurier, A., R. Chatelain, F. Chalons, and M. Pi´ echaud. 1979. Lysotypie de 823 souches de Listeria monocytogenes
isol´ ees en France de 1958 `
a 1978. Ann. Microbiol. (Inst. Pasteur). 130B:179–189.
6. Autio, T., S. Hielm, M. Miettinen, A.-M. Sj¨ oberg, K. Aarnisalo, J. Bj¨ orkroth, T. Mattila-Sandholm, and H. Korkeala.
1999. Sources of Listeria monocytogenes contamination in a cold-smoked rainbow trout processing plant detected by
pulsed-field gel electrophoresis typing. Appl. Environ. Microbiol. 65:150–155.
7. Ayres, J.C. 1967. Use of fluorescent antibody for the rapid detection of enteric organisms in egg, poultry and meat products.
Food Technol. 21:631–640.
8. Babacan, S., P. Pivarnik, S. Letcher, and A. Rand. 2002. Piezoelectric flow injection analysis biosensor for the detection
of Salmonella Typhimurium. J. Food Sci. 67:314–320.
9. Bachrach, U., and Z. Bachrach. 1974. Radiometric method for the detection of coliform organisms in water. Appl.
Microbiol. 28:169–171.
10. Baez, L.A., and V.K. Juneja. 1995. Nonradioactive colony hybridization assay for detection and enumeration of enterotoxigenic Clostridium perfringens in raw beef. Appl. Environ. Microbiol. 61:807–810.
11. Bastish, V.K., H. Chander, and G. Ranganathan. 1984. Incidence of enterococcal thermonuclease in milk and milk products.
J. Food Sci. 49:1610–1611, 1615.
12. Bautista, D.A., J.P. Vaillancourt, R.A. Clarke, S. Renwick, and M.W. Griffiths. 1995. Rapid assessment of the microbiological quality of poultry carcasses using ATP bioluminescence. J. Food Protect. 58:551–554.
13. Beezer, A.E., D. Newell, and H.J.V. Tyrrell. 1976. Application of flow microcalorimetry to analytical problems: The
preparation, storage and assay of frozen inocula of Saccharomyces cerevisiae. J. Appl. Bacteriol. 41:197–207.
14. Beezer, A.E., D. Newell, and H.J.V. Tyrrell. 1978. Characterisation and metabolic studies of Saccharomyces cerevisiae
and Kluyveromyces fragilis by flow microcalorimetry. Antonie Van Leeuwenhoek 45:55–63.