Abstract
In the developing world, enterotoxigenic Escherichia coli (ETEC) strains which produce enterotoxins are a significant cause of morbidity and mortality. Heat-labile (LT) toxin PCR detection methods have been described, but they have limited applications in a routine laboratory setting. A colorimetric DNA method for the rapid amplification and detection of the LT toxin gene in ETEC strains is described. Target amplification together with colorimetric detection would overcome many of the limitations of conventional PCR. This paper describes a colorimetric PCR detection method specific for LT-gene-encoding ETEC strains. DNA was extracted from two representative colonies from each bacterial isolate and amplified by PCR. Digoxigenin was incorporated into the amplification product, permitting a one-step direct detection using anti-digoxigenin alkaline phosphatase-conjugated antibody. This technique was applied to the investigation of 70 E. coli isolates derived from clinical fecal samples obtained from an Irish population. Eleven percent of the samples were LT positive, confirming the applicability of this method. All LT-positive ETEC strains (controls and clinical isolates) were detected, and no false-positive results occurred.
Full Text
The Full Text of this article is available as a PDF (261.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Abe A., Obata H., Matsushita S., Yamada S., Kudoh Y., Bangtrakulnonth A., Ratchtrachenchat O. A., Danbara H. A sensitive method for the detection of enterotoxigenic Escherichia coli by the polymerase chain reaction using multiple primer pairs. Zentralbl Bakteriol. 1992 Jul;277(2):170–178. doi: 10.1016/s0934-8840(11)80610-9. [DOI] [PubMed] [Google Scholar]
- Bej A. K., Mahbubani M. H. Applications of the polymerase chain reaction in environmental microbiology. PCR Methods Appl. 1992 Feb;1(3):151–159. doi: 10.1101/gr.1.3.151. [DOI] [PubMed] [Google Scholar]
- Dallas W. S., Falkow S. Amino acid sequence homology between cholera toxin and Escherichia coli heat-labile toxin. Nature. 1980 Dec 4;288(5790):499–501. doi: 10.1038/288499a0. [DOI] [PubMed] [Google Scholar]
- Edwards M. C., Gibbs R. A. Multiplex PCR: advantages, development, and applications. PCR Methods Appl. 1994 Feb;3(4):S65–S75. doi: 10.1101/gr.3.4.s65. [DOI] [PubMed] [Google Scholar]
- Frankel G., Giron J. A., Valmassoi J., Schoolnik G. K. Multi-gene amplification: simultaneous detection of three virulence genes in diarrhoeal stool. Mol Microbiol. 1989 Dec;3(12):1729–1734. doi: 10.1111/j.1365-2958.1989.tb00158.x. [DOI] [PubMed] [Google Scholar]
- Furrer B., Candrian U., Lüthy J. Detection and identification of E. coli producing heat-labile enterotoxin type I by enzymatic amplification of a specific DNA fragment. Lett Appl Microbiol. 1990 Jan;10(1):31–34. doi: 10.1111/j.1472-765x.1990.tb00088.x. [DOI] [PubMed] [Google Scholar]
- Gomes T. A., Rassi V., MacDonald K. L., Ramos S. R., Trabulsi L. R., Vieira M. A., Guth B. E., Candeias J. A., Ivey C., Toledo M. R. Enteropathogens associated with acute diarrheal disease in urban infants in São Paulo, Brazil. J Infect Dis. 1991 Aug;164(2):331–337. doi: 10.1093/infdis/164.2.331. [DOI] [PubMed] [Google Scholar]
- Holmstrøm K., Rossen L., Rasmussen O. F. A highly sensitive and fast nonradioactive method for detection of polymerase chain reaction products. Anal Biochem. 1993 Mar;209(2):278–283. doi: 10.1006/abio.1993.1120. [DOI] [PubMed] [Google Scholar]
- Honda T., Taga S., Takeda Y., Miwatani T. Modified Elek test for detection of heat-labile enterotoxin of enterotoxigenic Escherichia coli. J Clin Microbiol. 1981 Jan;13(1):1–5. doi: 10.1128/jcm.13.1.1-5.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kessler C. The digoxigenin:anti-digoxigenin (DIG) technology--a survey on the concept and realization of a novel bioanalytical indicator system. Mol Cell Probes. 1991 Jun;5(3):161–205. doi: 10.1016/0890-8508(91)90041-h. [DOI] [PubMed] [Google Scholar]
- Landegren U., Kaiser R., Caskey C. T., Hood L. DNA diagnostics--molecular techniques and automation. Science. 1988 Oct 14;242(4876):229–237. doi: 10.1126/science.3051381. [DOI] [PubMed] [Google Scholar]
- Lee C. H., Moseley S. L., Moon H. W., Whipp S. C., Gyles C. L., So M. Characterization of the gene encoding heat-stable toxin II and preliminary molecular epidemiological studies of enterotoxigenic Escherichia coli heat-stable toxin II producers. Infect Immun. 1983 Oct;42(1):264–268. doi: 10.1128/iai.42.1.264-268.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moseley S. L., Hardy J. W., Hug M. I., Echeverria P., Falkow S. Isolation and nucleotide sequence determination of a gene encoding a heat-stable enterotoxin of Escherichia coli. Infect Immun. 1983 Mar;39(3):1167–1174. doi: 10.1128/iai.39.3.1167-1174.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mullis K. B., Faloona F. A. Specific synthesis of DNA in vitro via a polymerase-catalyzed chain reaction. Methods Enzymol. 1987;155:335–350. doi: 10.1016/0076-6879(87)55023-6. [DOI] [PubMed] [Google Scholar]
- Riley L. K., Caffrey C. J. Identification of enterotoxigenic Escherichia coli by colony hybridization with nonradioactive digoxigenin-labeled DNA probes. J Clin Microbiol. 1990 Jun;28(6):1465–1468. doi: 10.1128/jcm.28.6.1465-1468.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sack D. A., Sack R. B. Test for enterotoxigenic Escherichia coli using Y-1 adrenal cells in miniculture. Infect Immun. 1975 Feb;11(2):334–336. doi: 10.1128/iai.11.2.334-336.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schultsz C., Pool G. J., van Ketel R., de Wever B., Speelman P., Dankert J. Detection of enterotoxigenic Escherichia coli in stool samples by using nonradioactively labeled oligonucleotide DNA probes and PCR. J Clin Microbiol. 1994 Oct;32(10):2393–2397. doi: 10.1128/jcm.32.10.2393-2397.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- So M., McCarthy B. J. Nucleotide sequence of the bacterial transposon Tn1681 encoding a heat-stable (ST) toxin and its identification in enterotoxigenic Escherichia coli strains. Proc Natl Acad Sci U S A. 1980 Jul;77(7):4011–4015. doi: 10.1073/pnas.77.7.4011. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tamanai-Shacoori Z., Jolivet-Gougeon A., Pommepuy M., Cormier M., Colwell R. R. Detection of enterotoxigenic Escherichia coli in water by polymerase chain reaction amplification and hybridization. Can J Microbiol. 1994 Apr;40(4):243–249. doi: 10.1139/m94-040. [DOI] [PubMed] [Google Scholar]