Bacterial overgrowth by indigenous microflora in the phytohemagglutinin-fed rat

1988 ◽  
Vol 34 (8) ◽  
pp. 1009-1013 ◽  
Author(s):  
J. G. Banwell ◽  
R. Howard ◽  
I. Kabir ◽  
J. W. Costerton
Keyword(s):  
Escherichia Coli ◽  
Time Course ◽  
Control Diet ◽  
Bacterial Overgrowth ◽  
Microbial Colonization ◽  
Facultative Anaerobe ◽  
E Coli ◽  
Heat Stable ◽  
Red Kidney Bean ◽  
Indigenous Microflora

Phytohemagglutinin lectin (PHA) derived from red kidney bean (Phaseolus vulgaris) causes bacterial and protozoal colonization of the rat small intestine. To provide additional insights into this phenomenon we have studied the time course and population dynamics of microbial colonization of the major aerobe – facultative anaerobe groups which characterize this microflora. Compared with controls, PHA caused proliferation of a consistent adherent microbial flora in the jejunum (P < 0.01). The predominant bacteria identified were Escherichia coli. a Streptococcal sp., and Lactobacillus. Escherichia coli isolates expressed no predominant serotype or fimbriae; none elaborated heat-labile or heat-stable toxin. Both E. coli and Streptococcal sp. populations increased within 24 h of PHA feeding and were sustained during further exposure to PHA (P < 0.05). On reversion to a control diet, coliform counts fell progressively within 24–48 h and continued to decline, whereas gram-positive rod and coccus flora became the more prominent colonizers through days 1 to 4 of the reversion.

scholarly journals Feed Fermentation with Reuteran- and Levan-Producing Lactobacillus reuteri Reduces Colonization of Weanling Pigs by Enterotoxigenic Escherichia coli

2015 ◽  
Vol 81 (17) ◽  
pp. 5743-5752 ◽  
Author(s):  
Yan Yang ◽  
Sandra Galle ◽  
Minh Hong Anh Le ◽  
Ruurd T. Zijlstra ◽  
Michael G. Gänzle
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Reuteri ◽  
Control Diet ◽  
Enterotoxigenic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Heat Stable ◽  
Copy Numbers ◽  
Fermented Feed ◽  
The Impact

ABSTRACTThis study determined the effect of feed fermentation withLactobacillus reuterion growth performance and the abundance of enterotoxigenicEscherichia coli(ETEC) in weanling piglets.L. reuteristrains produce reuteran or levan, exopolysaccharides that inhibit ETEC adhesion to the mucosa, and feed fermentation was conducted under conditions supporting exopolysaccharide formation and under conditions not supporting exopolysaccharide formation. Diets were chosen to assess the impact of organic acids and the impact of viableL. reuteribacteria. Fecal samples were taken throughout 3 weeks of feeding; at the end of the 21-day feeding period, animals were euthanized to sample the gut digesta. The feed intake was reduced in pigs fed diets containing exopolysaccharides; however, feed efficiencies did not differ among the diets. Quantification ofL. reuteriby quantitative PCR (qPCR) detected the two strains used for feed fermentation throughout the intestinal tract. Quantification ofE. coliand ETEC virulence factors by qPCR demonstrated that fermented diets containing reuteran significantly (P< 0.05) reduced the copy numbers of genes forE. coliand the heat-stable enterotoxin in feces compared to those achieved with the control diet. Any fermented feed significantly (P< 0.05) reduced the abundance ofE. coliand the heat-stable enterotoxin in colonic digesta at 21 days; reuteran-containing diets reduced the copy numbers of the genes forE. coliand the heat-stable enterotoxin below the detection limit in samples from the ileum, the cecum, and the colon. In conclusion, feed fermentation withL. reuterireduced the level of colonization of weaning piglets with ETEC, and feed fermentation supplied concentrations of reuteran that may specifically contribute to the effect on ETEC.

Comparison of colony and stool blots for detection of enteropathogens by DNA probes

1991 ◽  
Vol 37 (5) ◽  
pp. 407-410
Author(s):  
Mônica A. M. Vieira ◽  
Beatriz E. C. Guth ◽  
Tânia A. T. Gomes
Keyword(s):  
Escherichia Coli ◽  
Key Words ◽  
Sensitivity And Specificity ◽  
Dna Probes ◽  
Type I ◽  
Enteropathogenic Escherichia Coli ◽  
Key Words Dna ◽  
E Coli ◽  
Heat Stable

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.

scholarly journals Erratum

2003 ◽  
Vol 130 (3) ◽  
pp. 573-573
Author(s):  
Z. ZHOU ◽  
J. OGASAWARA ◽  
Y. NISHIKAWA
Keyword(s):  
Escherichia Coli ◽  
E Coli ◽  
Heat Stable ◽  
Epidemiol Infect

Epidemiol. Infect. 128 (2002), 363–371An outbreak of gastroenteritis in Osaka, Japan due toEscherichia coliserogroup O166[ratio ]H15 that had a coding gene for enteroaggregativeE. coliheat-stable enterotoxin 1 (EAST1)Tables 1 and 2 were omitted

scholarly journals Evolution of diarrheagenic Escherichia coli pathotypes in India

2019 ◽  
Vol 11 (04) ◽  
pp. 346-351
Author(s):  
Pankaj Singh ◽  
Sharda C. Metgud ◽  
Subarna Roy ◽  
Shashank Purwar
Keyword(s):  
Escherichia Coli ◽  
Cross Sectional Study ◽  
Clinical Settings ◽  
Accurate Identification ◽  
Cross Sectional ◽  
E Coli ◽  
Medical College ◽  
Diarrheagenic Escherichia Coli ◽  
Proper Management ◽  
Heat Stable

Abstract CONTEXT: Diarrheagenic Escherichia coli (DEC) is the leading cause of infectious diarrhea in developing countries. On the basis of virulence and phenotypic characteristics, the DEC is categorized into multiple pathotypes. Each pathotype has different pathogenesis and geographical distribution. Thus, the proper management of disease relies on rapid and accurate identification of DEC pathotypes. AIMS: The aim of the study was to determine the prevalence of DEC pathotypes in India. MATERIALS AND METHODS: A cross-sectional study was carried out between January 2008 and December 2012 at Jawaharlal Nehru Medical College and KLES Dr. Prabhakar Kore Hospital and Medical Research Center, Belgaum (Karnataka), India. A total of 300 stool samples were collected from diarrhea patients with age >3 months. The DEC was identified by both conventional and molecular methods. RESULTS: Of 300 samples, E. coli were detected in 198 (66%) and 170 (56.6%) samples by culture and polymerase chain reaction, respectively. Among DEC (n = 198) isolates, eae gene (59.5%) was the most prevalent followed by stx (27.7%), east (27.2%), elt (12.6%), est (10.6%), ipaH (5.5%), and eagg (1.5%) genes. On the basis of virulence genes, enteropathogenic E. coli (33.8%) was the most common pathotype followed by Shiga toxin-producing E. coli (STEC, 23.2%), enterotoxigenic E. coli (ETEC, 13.6%), enteroinvasive E. coli (5.5%), enteroaggregative heat-stable enterotoxin 1-harboring E. coli (EAST1EC, 4.5%), STEC/ETEC (3.5%), STEC/enteroaggregative E. coli (STEC/EAEC, 1.0%), and EAEC (0.05%). CONCLUSIONS: The hybrid DEC is potentially more virulent than basic pathotypes. The pathotyping should be included in clinical settings for the proper management of DEC-associated diarrhea.

scholarly journals Properties of human testis-specific lactate dehydrogenase expressed from Escherichia coli

1991 ◽  
Vol 273 (3) ◽  
pp. 587-592 ◽  
Author(s):  
K M LeVan ◽  
E Goldberg
Keyword(s):  
Escherichia Coli ◽  
Lactate Dehydrogenase ◽  
Prokaryotic Expression ◽  
Specific Activity ◽  
Human Testis ◽  
Reading Frame ◽  
E Coli ◽  
Heat Stable ◽  
Prokaryotic Expression Vector ◽  
Tac Promoter

The cDNA encoding the C4 isoenzyme of lactate dehydrogenase (LDH-C4) was engineered for expression in Escherichia coli. The Ldh-c open reading frame was constructed as a cassette for production of the native protein. The modified Ldh-c cDNA was subcloned into the prokaryotic expression vector pKK223-3. Transformed E. coli cells were grown to mid-exponential phase, and induced with isopropyl beta-D-thiogalactopyranoside for positive regulation of the tac promoter. Induced cells expressed the 35 kDa subunit, which spontaneously formed the enzymically active 140 kDa tetramer. Human LDH-C4 was purified over 200-fold from litre cultures of cells by AMP and oxamate affinity chromatography to a specific activity of 106 units/mg. The enzyme was inhibited by pyruvate concentrations above 0.3 mM, had a Km for pyruvate of 0.03 mM, a turnover number (nmol of NADH oxidized/mol of LDH-C4 per min at 25 degrees C) of 14,000 and was heat-stable.

Escherichia coli heat-stable toxin: its effect on motility of the small intestine

1982 ◽  
Vol 242 (4) ◽  
pp. G360-G363 ◽  
Author(s):  
J. R. Mathias ◽  
J. Nogueira ◽  
J. L. Martin ◽  
G. M. Carlson ◽  
R. A. Giannella
Keyword(s):  
Escherichia Coli ◽  
Small Intestine ◽  
Action Potential ◽  
Myoelectric Activity ◽  
Complex Activity ◽  
E Coli ◽  
Heat Stable ◽  
Rabbit Small Intestine ◽  
Weight Substance

Escherichia coli heat-stable enterotoxin is a low-molecular-weight substance that has been shown to induce the active secretion of fluid and electrolytes in the small intestine. In this study, we have characterized the effects of purified E. coli heat-stable toxin (ST, strain 18D, serotype 042:K86:H37) on the motility of rabbit small intestine by using myoelectric recording techniques. Substances, such as cholera toxin, that activate the adenylate cyclase-cAMP system induced predominantly migrating action-potential complex activity. E. coli ST, a toxin that activates the guanylate cyclase-cGMP system, was infused into isolated in vivo ileal loops of New Zealand White rabbits. Inactivated toxin was also studied by exposing the ST to 1 mM dithiothreitol for 90 min. Active E. coli ST induced only repetitive bursts of action potentials. When the toxin was inactivated with dithiothreitol, no alteration in myoelectric activity was observed. We speculate that repetitive bursts of action-potential activity may represent a virulent factor of the bacterium, altering motor activity to slow transit and allowing for bacterial proliferation and invasion.

scholarly journals Comparison of Sorbitol MacConkey and Hemorrhagic Coli Agars for Recovery of Escherichia coli 0157:H7 from Brie, Ice Cream, and Whole Milk

1997 ◽  
Vol 80 (2) ◽  
pp. 335-340 ◽  
Author(s):  
Thomas S Hammack ◽  
Peter Feng ◽  
R Miguel Amaguaña ◽  
Geraldine June ◽  
Patricia S Sherrod ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ice Cream ◽  
Apparent Effect ◽  
Dairy Foods ◽  
E Coli ◽  
Whole Milk ◽  
Plate Counts ◽  
Indigenous Microflora

Abstract The relative efficacies of hemorrhagic coli (HC) agar and several formulations of sorbitol Mac-Conkey (SorMac) agar, with and without 0.1 % (w/v) 4-methyllumbelliferyl-ß-D-glucuronide (MUG), in recovering unstressed and heat-stressed Escherichia coli 0157:H7 from Brie cheese, ice cream, and whole milk were determined. Recovery of unstressed E. coli 0157:H7 was determined quantitatively by spread-plating diluted samples onto different agars and performing plate counts. Recovery of stressed E. coli 0157:H7 was determined qualitatively by enriching samples in modified trypticase soy broth, streaking the incubated enrichments, and isolating E. coli 0157:H7 colonies from the agars. HC agar and the SorMac agar formulations did not differ significantly in their ability to recover unstressed E. coli 0157:H7 from ice cream and whole milk; however, HC agar recovered significantly more unstressed E. coli 0157:H7 from Brie cheese than did the SorMac agar formulations. Bacteriological Analytical Manual and Oxoid SorMac agar formulations made from individual ingredients, did not differ significantly in recovering unstressed E. coli 0157:H7 from Brie cheese. The efficiency of the commercially available Oxoid SorMac agar could not be determined because of overgrowth by indigenous microflora. HC and SorMac agars did not differ significantly in recovering stressed E. coli 0157:H7 from Brie cheese, ice cream, and whole milk. MUG had no apparent effect on recovery of either stressed or unstressed E. coli 0157:H7 from the dairy foods examined.

scholarly journals DIFFERENTIAL INHIBITORY EFFECTS OF CHOLERA TOXOIDS AND GANGLIOSIDE ON THE ENTEROTOXINS OF VIBRIO CHOLERAE AND ESCHERICHIA COLI

1973 ◽  
Vol 137 (4) ◽  
pp. 1009-1023 ◽  
Author(s):  
Nathaniel F. Pierce
Keyword(s):  
Escherichia Coli ◽  
Binding Sites ◽  
Competitive Inhibitor ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
E Coli ◽  
Stable Component ◽  
Heat Stable ◽  
Cholera Enterotoxin ◽  
Gut Mucosa

Natural cholera toxoid appears to act as a competitive inhibitor of cholera enterotoxin and is thus a useful tool for studying the interaction of cholera enterotoxin with cell membranes. Cholera enterotoxin binds to gut mucosa more rapidly than does its natural toxoid. Once binding occurs, however, it appears to be prolonged for both materials. Formalinized cholera toxoid has no inhibitory effect upon cholera enterotoxin. Enterotoxic activity, ability to bind to gut mucosa, and antitoxigenicity appear to be independent properties of cholera enterotoxin. Natural cholera toxoid does not inhibit Escherichia coli enterotoxin, indicating that although the two enterotoxins activate the same mucosal secretory mechanism they occupy different binding sites in the mucosa. Ganglioside, which may be the mucosal receptor of cholera enterotoxin, is highly efficient in deactivating cholera enterotoxin. By contrast, ganglioside is relatively inefficient in deactivating heat-labile E. coli enterotoxin and is without effect upon the heat-stable component of E. coli enterotoxin. These findings suggest that ganglioside is not likely to be the mucosal receptor for E. coli enterotoxin. Differences in cellular binding of E. coli and cholera enterotoxins may explain, at least in part, the marked differences in the time of onset and duration of their effects upon gut secretion.

scholarly journals Enteroaggregative Escherichia coli Heat-Stable Enterotoxin Is Not Restricted to Enteroaggregative E. coli

1996 ◽  
Vol 173 (4) ◽  
pp. 1019-1022 ◽  
Author(s):  
S. J. Savarino ◽  
A. McVeigh ◽  
J. Watson ◽  
A. Cravioto ◽  
J. Molina ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
E Coli ◽  
Heat Stable

Multiplex Real-Time PCR Detection of Heat-Labile and Heat-Stable Toxin Genes in Enterotoxigenic Escherichia coli †

2006 ◽  
Vol 69 (2) ◽  
pp. 412-416 ◽  
Author(s):  
MICHAEL A. GRANT ◽  
JINXIN HU ◽  
KAREN C. JINNEMAN
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Real Time Pcr ◽  
Membrane Filtration ◽  
Enterotoxigenic Escherichia Coli ◽  
Pcr Analysis ◽  
E Coli ◽  
Toxin Genes ◽  
Heat Stable ◽  
Heat Labile

A multiplex real-time PCR method was developed for detection of heat-labile and heat-stable toxin genes in enterotoxigenic Escherichia coli. Approximately 10 CFU per reaction mixture could be detected in rinsates from produce samples. Several foods representative of varieties previously shown to have caused enterotoxigenic E. coli outbreaks were spiked and enriched for 4 or 6 h. Both heat-labile and heat-stable toxin genes could be detected in the foods tested, with the exception of hot sauce, with threshold cycle values ranging from 25.2 to 41.1. A procedure using membrane filtration which would allow enumeration of the enterotoxigenic E. coli population in a food sample in less than 28 h by real-time PCR analysis of colonies picked from media highly selective for E. coli was also developed.

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