Heat-Stable Enterotoxin of Escherichia coli

DNA probes that identify genes coding for heat-labile type I (LT-I) and heat-stable type 1 (ST-I) enterotoxins, enteropathogenic Escherichia coli adherence factor (EAF), and Shigella-like, invasiveness (INV) are used to evaluate the sensitivity and specificity of stool blots in comparison with the sensitivity and specificity of colony blots in detecting enteropathoghens. The sensitivities of the probes in stool blots are 91.7% for the LT-I probe, 76.9% for the ST-I probes, 78.9% for the EAF probe, and 45.5% for the INV probe. The specificity of all probes is higher than 95%. In general, the stool blot method identifies as many if not more LT-I-, ST-I-, and EAF-producing E. coli infections than the colony blots. Key words: DNA probes, stool blots, enteropathogens, diagnosis.

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Use of a Multiplex PCR System for the Simultaneous Detection of Heat Labile Toxin I and Heat Stable Toxin II Genes of Enterotoxigenic Escherichia coli in Skim Milk and Porcine Stool

Journal of Food Protection ◽

10.4315/0362-028x-61.2.141 ◽

1998 ◽

Vol 61 (2) ◽

pp. 141-145 ◽

Cited By ~ 12

Author(s):

HAU-YANG TSEN ◽

LIANG-ZHAO JIAN ◽

WAN-RONG CHI

Keyword(s):

Escherichia Coli ◽

Multiplex Pcr ◽

Simultaneous Detection ◽

Skim Milk ◽

Pcr Primers ◽

Enterotoxigenic Escherichia Coli ◽

Farm Animals ◽

Target Cells ◽

Heat Stable ◽

Heat Labile

Enterotoxigenic Escherichia coli (ETEC) strains which produce heat labile and/or heat stable toxins (LT and ST) may cause diarrhea in humans and farm animals. Using PCR primers specific for the LT I and ST II genes, a multiplex PCR system which allows detection of LT I- and ST II-producing ETEC strains was developed. When skim milk was used for a PCR assay, it was found that if target cells in the sample were precultured in MacConkey broth for 8 h prior to PCR as few as 100 cells per ml of the sample could be detected. Without the preculture step, 104 CFU of target cells per 0.2 g of porcine stool specimen were required to generate visible PCR products. The multiplex PCR System can be used for rapid testing of fecal specimens, food and possibly environmental samples for the presence of ETEC strains.

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Isolation and characterization of the heat stable enterotoxin from a pathogenic bovine strain of Escherichia coli

Veterinary Microbiology ◽

10.1016/0378-1135(84)90009-9 ◽

1984 ◽

Vol 9 (4) ◽

pp. 399-414 ◽

Cited By ~ 8

Author(s):

Charles Gerday ◽

Marianne Herman ◽

Jacques Olivy ◽

Nicole Gerardin-Otthiers ◽

Dominique Art ◽

...

Keyword(s):

Escherichia Coli ◽

Heat Stable ◽

Isolation And Characterization ◽

Bovine Strain

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Synthesis and biological properties of carba-analogs of heat-stable enterotoxin (ST) produced by enterotoxigenic Escherichia coli

Biochemical and Biophysical Research Communications ◽

10.1016/0006-291x(91)90375-h ◽

1991 ◽

Vol 176 (3) ◽

pp. 958-965 ◽

Cited By ~ 4

Author(s):

Yuji Hidaka ◽

Katsuhiko Ohmori ◽

Akihiro Wada ◽

Hiroshi Ozaki ◽

Hideaki Ito ◽

...

Keyword(s):

Escherichia Coli ◽

Biological Properties ◽

Enterotoxigenic Escherichia Coli ◽

Heat Stable

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A modified bioassay for heat-stable Escherichia coli enterotoxin

Canadian Journal of Microbiology ◽

10.1139/m77-049 ◽

1977 ◽

Vol 23 (3) ◽

pp. 331-336 ◽

Cited By ~ 8

Author(s):

S. Stavric ◽

D. Jeffrey

Keyword(s):

Escherichia Coli ◽

Body Weight ◽

Incubation Time ◽

Evans Blue ◽

Room Temperature ◽

Blue Dye ◽

Evans Blue Dye ◽

Heat Stable ◽

Stomach Distention ◽

Time Required

Infant mice were injected orally with preparations containing Escherichia coli heat-stable enterotoxin (ST) and Evans blue dye, and incubated at 22 °C. With enterotoxin-positive samples, the stomach was distended and contained essentially all of the dye. With enterotoxin-negative samples, the stomach remained normal in size and the dye passed freely into the intestines. The time required to obtain the maximum ratio of gut weight to body weight varied from 30 to 90 min and was dependent upon the concentration of enterotoxin. Heat-labile enterotoxin (LT) had no effect during this period.Based on these findings, the mouse incubation time was reduced from 4 h to 90 min, and the heating of test samples was retained only for confirmation of ST. The location of the dye and stomach distention served as an indicator of positive responses to ST. Incubation of the mice at room temperature (22 °C) was found satisfactory.

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