No abstract available.
Enterotoxigenic Escherichia coli* ; Enterotoxins*

No abstract available.
Enterotoxigenic Escherichia coli*

No abstract available.
Enterotoxigenic Escherichia coli* ; Enterotoxins*

Background: aaP, aggR, and astA have been found to play important roles in diarrheal pathogenecity of EAEC. They may be exist in other diarrheagenic E.coli (DEC). Objectives: To determine the distribution of aaP, aggR, and astA in ETEC, EPEC, EIEC and non-diarrheagenic E.coli. Subjects and method: 75 strains of ETEC, EPEC, EIEC and 100 non-DEC have been screen by PCR with primers specific toaaP, aggR, and astA. Results: aaP, aggR, and astA have been seen in DEC with the prevence from 7 to 72,7%. The highest prevence was in EIEC, 72,7% for aap; 45,5% in EIEC for aggR; and 50% in ETEC for astA. 14% of non-DEC harbored aggR and more than 30% harbored aap and astA. Conclusion: This finding has contributed to understanding the distribution of aap, aggR and astA in ETEC, EPEC, EIEC and non-DEC as well.
Enterotoxigenic Escherichia coli ; Enteropathogenic Escherichia coli ; Escherichia coli ;

Objectives: Probiotic supplementation often only leads to transient improvement in the gut microbiome. Potential prebiotics, such as the oligosaccharide-rich varieties of Dioscorea esculenta tubers, can potentially bridge the gap between supplementation and persistent colonization. Thus, this study aimed to assess the ability of D. esculenta tubers to promote the growth of probiotic Lactobacillus sp. in vitro selectively.

Methods: The prebiotic activity of the selected varieties of Dioscorea esculenta tubers was evaluated via compe titive growth assay, wherein the ratios of probiotic Lactobacillus sp. over enterotoxigenic Escherichia coli (ETEC) or "prebiotic ratios" were compared following treatment.

Results: Negative control (0.9% NaCl solution) produced a ratio of 0.88, Lowland and Highland varieties produced ratios of 1.26 and 1.29, respectively, and positive control (inulin) produced 1.54. The two varieties had comparable ratios to one another (p > 0.05), and significantly higher ratios than the negative control (p < 0.05). Both varieties have significant prebiotic activity. Compared to inulin, the two varieties' prebiotic activity was 84% as effective.

Conclusion: Overall, the tubers promoted the growth of Lactobacillus sp. over ETEC. The crude tuber samples, given their availability and affordability, can be easily integrated into the local diet to contribute to the improvement of the general population's health.

Field efficacy of enterotoxigenic Escherichia coli-specific phage (PhiCJ19) as a feed additive was evaluated in weaning piglets. Fifty-four piglets at 3~4 weeks old were allocated in three different groups and two of them were fed with bacteriophage at different concentrations (10(6) PFU/kg feed and 10(8) PFU/kg feed, respectively) for 30 days. Body weight and feed intake were measured at 10 days interval and body condition and fecal score were inspected every day. Based on the measurement, feed conversion rate (FCR) and average daily gain (ADG) of each group during 30 days were analyzed. The analysis suggests that the bacteriophage may help the improvement of FCR and ADG at 10(8) PFU/kg of bacteriophage feeding group in 30 days. A result from analysis of fecal score indicates that the bacteriophage also may help to relieve the intermittent diarrhea in post-weaning stage. Those results suggest that bacteriophage might help the growth of piglets in post-weaning stage.
Bacteriophages ; Body Weight ; Diarrhea ; Enterotoxigenic Escherichia coli ; Escherichia ; Weaning

The hydrophobicity assay and DNA probe hybridization assay were compared for analysis of enterotoxigenic Escherichia coli(ETEC), heat-labile enterotoxin(LT) and heat-stable enterotoxin (ST). The ETEC isolated from diarrheal patients were serotyped and investigated for the presence of colonization factor antigens CFA/1, CFA/II, CFA/III and CFA/IV with the expression of mannose-resistant hemagglutination(MRHA) and the levels of surface hydrophobicity. The following results were obtained. 1. Out of these 48 strains, 34 strains were found to be positive for LT production by DNA probe hybridization assay. Out of 34 strains, 1 strain was ST producer, 25 strains were LT producers, and 8 strains were produced both ST+LT producers by DNA probe hybridization assay. 2. Out of 34 strains of positive DNA probe hybridization test, 31 strains was positive in the hydrophobicity test. Among strains of positive hydrophobicity test, 20, 1, and 7 strains produced only LT, only ST and both ST-LT, respectively. Screening efficiency for identifying ETEC by salting out test was 82.4% in sensitivity and 78.6% in specificity. For ETEC detection, the hydrophobicity assay was the least sensitive but was simple, rapid and a good substitute for the DNA probe hybridization assay. 4. CFAs were identified in 43.8% of ETEC strains; 2.1% of the CFAs strains with CFAs harbored CFA/I, 29.2% carried CFA/II, 16.7% carried CFA/III and CFA/IV. And 35.4% expressed none of these CFAs. CFA/I was found in ETEC of serotype 0128: K67, CFA/II was 0128: K67, 0142: K+ and 0159: K+, CFA/III was 086a: K15 and 0128: K67, CFA/IV was 0 86a: K15, 0128: K67, 0125: K70 and 0148: K+.
Colon ; DNA* ; Enterotoxigenic Escherichia coli* ; Enterotoxins ; Escherichia ; Humans ; Hydrophobic and Hydrophilic Interactions* ; Mass Screening ; Sensitivity and Specificity

To construct a novel vaccine candidate against bovine enterotoxigenic Escherichia coli (ETEC), FanC, the major subunit of K99 fimbriae adhesion, was inserted into secretion plasmid pYA3560 containing a β-lactamase secretion system. This was then transformed into Δasd Δcrp Salmonella (S.) Typhimurium and designated as JOL950. Secretion of recombinant fanC fimbrial antigens was confirmed by immunoblot analysis. Groups of mice were inoculated with single or double doses of JOL950. Another group was used as a negative control. Compared to control mice, all immunized mice had significantly higher levels (p < 0.05) of serum immunoglobulin (Ig)G, and secretory IgA against FanC. The IgG2a and IgG1 titer assays revealed that immunization highly induced IgG2a compared to that of IgG1, indicating that T helper-1- related cell-mediated immune responses may be elicited by JOL950. The results show that both systemic and mucosal immunities against selected fimbrial antigens of bovine ETEC expressed by a live attenuated S. Typhimurium strain are prominently produced in mice immunized with JOL950 via an oral route.
Animals ; Enterotoxigenic Escherichia coli* ; Immunization ; Immunoglobulin A, Secretory ; Immunoglobulin G ; Immunoglobulins ; Mice* ; Plasmids ; Salmonella*

OBJECTIVE7 variable but nonculturable-state strains of Enterotoxigenic Escherichia coli (ETEC) during the routine bacterial subculture were found in our lab and their morphology and antigen studied. Biological features, antigens and pathogenicity of the revertants were also tested and compared to that of the initial strains in order to detect their variations.

METHODSBiological variations between the variable but nonculturable-state and the revertant of every strain were detected, using the routine gram-staining, reverting the isolates in animal intestinal, reverting their pathogenicity, serological agglutination, biochemical identifications and antibiotic resistance tests.

RESULTSFor the 7 variable but nonculturable-state strains of ETEC,other than the trains that had changed into sphero vegetale cells, there were no other obvious variations found. However, high pathogenicity of these strains still remained.

CONCLUSIONThe presence of variable but nonculturable-state strains suggested that the routine method of bacteria storage should be changed and more attention should be paid to realize the existence of this kind of bacteria during the routine surveillance of the communicable diseases.

BACKGROUND: We investigated the prevalence of various pathogens (13 enteric bacteria and 5 viruses) which cause diarrhea using multiplex PCR of stool specimens and compared two multiplex PCR methods for detecting diarrheagenic Escherichia coli. METHODS: A total of 405 stool specimens submitted between November 2010 to February 2011 for routine culture of enteric pathogens were included and screened for five viruses (astrovirus, Group A rotavirus, enteric adenovirus, norovirus G1/G2) and eight bacteria (Salmonella spp., Shigella spp., Campylobacter spp., Vibrio spp., C. difficile Toxin B, C. perfringens, Y. enterolytica, Aeromonas spp.) using the Seeplex(R) Diarrhea ACE detection kit (Seegene). In addition, virulence-associated genes of enteropathogenic E. coli, (EPEC), enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli, (EIEC), enterotoxigenic E. coli (ETEC), and enteroaggressive E. coli (EAEC) were detected using 16-plex PCR and a commercial diarrheagenic E. coli detection (DEC) PCR kit (SSI Diagnostica). RESULTS: Overall, 138 (34.1%) of 405 samples was positive for pathogen. The positive rate for virus was 18.5%. norovirus G2, Group A rotavirus, enteric adenovirus, astrovirus and norovirus G1 were detected in 40, 23, 8, 3 and 1 samples, respectively. The positive rate for bacteria was 24.4% (99/405). C. difficile toxin B was the most frequently detected, followed by C. perfringens, EPEC, and EAEC. The agreements of the two multiplex PCR methods for detecting EPEC and EHEC were 99.3% and 100%, respectively. CONCLUSION: The detection rate was high (34.1%) including various diarrheagenic E. coli (6.2%) and C. perfringens (5.2%). Multiplex PCR is thus useful for detecting various pathogens.
Adenoviridae ; Aeromonas ; Bacteria ; Campylobacter ; Diarrhea ; Enterobacteriaceae ; Enterohemorrhagic Escherichia coli ; Enteropathogenic Escherichia coli ; Enterotoxigenic Escherichia coli ; Escherichia ; Escherichia coli ; Multiplex Polymerase Chain Reaction ; Norovirus ; Polymerase Chain Reaction ; Prevalence ; Rotavirus ; Shigella ; Vibrio ; Viruses