Abstract
A rapid method was developed to quantify toxigenic Escherichia coli, using a membrane filter procedure. After filtration of samples, the membrane filter was first incubated on a medium selective for E. coli (24 h, 44 degrees C) and then transferred to tryptic soy agar (3%; 6 h, 37 degrees C). To assay for labile toxin-producing colonies, the filter was then transferred to a monolayer of Y-1 cells, the E. coli colonies were marked on the bottom of the petri dish, and the filter was removed after 15 min. The monolayer was observed for a positive rounding effect after a 15- to 24-h incubation. The method has an upper limit of detecting 30 toxigenic colonies per plate and can detect as few as one toxigenic colony per plate. A preliminary screening for these enterotoxigenic strains in polluted waters and known positive fecal samples was performed, and positive results were obtained with fecal samples only.
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Selected References
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- Donta S. T. Editorial: Gastroenterologists on the move: the nature of travelers' diarrhea. N Engl J Med. 1976 Jun 10;294(24):1340–1341. doi: 10.1056/NEJM197606102942409. [DOI] [PubMed] [Google Scholar]
- Donta S. T., Moon H. W., Whipp S. C. Detection of heat-labile Escherichia coli enterotoxin with the use of adrenal cells in tissue culture. Science. 1974 Jan 25;183(4122):334–336. doi: 10.1126/science.183.4122.334. [DOI] [PubMed] [Google Scholar]
- Donta S. T., Moon H. W., Whipp S. C., Skartvedt S. M. In vitro production and inactivation of Escherichia coli enterotoxin. Gastroenterology. 1974 Nov;67(5):983–990. [PubMed] [Google Scholar]
- Echeverria P., Verhaert L., Basaca-Sevilla V., Banson T., Cross J., Orskov F., Orskov I. Search for heat-labile enterotoxigenic Escherichia coli in humans, livestock, food, and water in a community in the Philippines. J Infect Dis. 1978 Jul;138(1):87–90. doi: 10.1093/infdis/138.1.87. [DOI] [PubMed] [Google Scholar]
- Geldreich E. E., Jeter H. L., Winter J. A. Technical considerations in applying the membrane filter procedure. Health Lab Sci. 1967 Apr;4(2):113–125. [PubMed] [Google Scholar]
- Gorbach S. L., Kean B. H., Evans D. G., Evans D. J., Jr, Bessudo D. Travelers' diarrhea and toxigenic Escherichia coli. N Engl J Med. 1975 May 1;292(18):933–936. doi: 10.1056/NEJM197505012921801. [DOI] [PubMed] [Google Scholar]
- Merson M. H., Morris G. K., Sack D. A., Wells J. G., Feeley J. C., Sack R. B., Creech W. B., Kapikian A. Z., Gangarosa E. J. Travelers' diarrhea in Mexico. A prospective study of physicians and family members attending a congress. N Engl J Med. 1976 Jun 10;294(24):1299–1305. doi: 10.1056/NEJM197606102942401. [DOI] [PubMed] [Google Scholar]
- Morgan G. B., Gubbins P., Morgan V. A critical appraisal of the membrane filter technic. Health Lab Sci. 1965 Oct;2(4):227–237. [PubMed] [Google Scholar]
- Morris G. K., Merson M. H., Sack D. A., Wells J. G., Martin W. T., Dewitt W. E., Feeley J. C., Sack R. B., Bessudo D. M. Laboratory investigation of diarrhea in travelers to Mexico: evaluation of methods for detecting enterotoxigenic Echerichia coli. J Clin Microbiol. 1976 May;3(5):486–495. doi: 10.1128/jcm.3.5.486-495.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sack R. B., Gorbach S. L., Banwell J. G., Jacobs B., Chatterjee B. D., Mitra R. C. Enterotoxigenic Escherichia coli isolated from patients with severe cholera-like disease. J Infect Dis. 1971 Apr;123(4):378–385. doi: 10.1093/infdis/123.4.378. [DOI] [PubMed] [Google Scholar]
- Sack R. B. Human diarrheal disease caused by enterotoxigenic Escherichia coli. Annu Rev Microbiol. 1975;29:333–353. doi: 10.1146/annurev.mi.29.100175.002001. [DOI] [PubMed] [Google Scholar]