Methodology for Recovery and Identification of Enteropathogenic Escherichia coli

1974 ◽  
Vol 57 (1) ◽  
pp. 101-110
Author(s):  
Ira J Mehlman ◽  
Arvey C Sanders ◽  
Nicholas T Simon ◽  
Joseph C Olson
Keyword(s):  
Serial Passage ◽  
Semisolid Medium ◽  
E Coli ◽  
Serological Examination ◽  
Food Borne ◽  
Shigella Species ◽  
Animal Pathogens ◽  
Secondary Reactions ◽  
Food Borne Illness ◽  
Flagellar Antigen

Abstract Pathogenic biotypes of E. coli have been incriminated in food-borne illness. Sensitivity to elevated temperature and atypical behavior precluded assessment of their incidence. A tentative recovery procedure involves direct streak, preenrichment in MacConkey broth at 35°C and transfer to lauryl tryptose broth with incubation at 44°C, and pre-enrichment in nutrient broth at 35°C and transfer to enteric enrichment broth with incubation at 41.5°C. Serological examination of enrichment simplifies analysis. Levine's eosin methylene blue agar is recommended for rapid lactose fermenters; MacConkey's agar should be used for slow fermenters. Primary screening reactions include H2S, arabinose, urease, o-nitrophenyl-β-D-galactosidase, and indole. Secondary reactions comprise lysine decarboxylase, Voges-Proskauer (at 22°C), and other tests required to differentiate E. coli from Citrobacter diver sus, C. freundii, Enterobacter hafniae, Klebsiella pneumoniae, and Shigella species. Slide and tube agglutination reactions are necessary for identification of somatic and capsular antigens. Enhancement of motility by serial passage in a semisolid medium is essential for recognition of flagellar antigen. Confirmatory reactions include nitrate reduction, cytochrome oxidase, and Gram stain. Potentiality for quantitation, applicability to animal pathogens, and ecological samples are discussed.

scholarly journals Bacterial Contamination Associated with Retail Chicken Carcasses in Osogbo, Nigeria

2015 ◽  
Vol 05 (04) ◽  
pp. 045-050
Author(s):  
Adesiji Yemisi Olukemi ◽  
Igbinigie Mavis Osas ◽  
Olaitan Janet Olubukola ◽  
Ogah Ikhevha Jeremiah
Keyword(s):  
Diffusion Method ◽  
Isolation And Identification ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Poultry Products ◽  
Bacterial Contaminants ◽  
Food Borne ◽  
Chicken Carcass ◽  
Hygiene Measures ◽  
Food Borne Illness

Abstract Background: Worldwide, food borne illness is often associated with consumption of meat and poultry products sold at retail markets. A study on the bacteriological status of chicken carcass in Osogbo, Nigeria, was carried out to determine the prevalence of Arcobacter species, Escherichia coli and Staphylococcus aureus in chicken carcasses. Methodology: A total of 100 samples of chicken carcasses were collected from two major processing points in Osogbo, Nigeria. The samples were analysed for the presence of bacterial contaminants using standard microbiological isolation and identification procedures, with antimicrobial susceptibility test performed using the disk diffusion method. Result: Of hundred chicken carcasses sampled, 38% were positive for Arcobacter species and E. coli while 60% accounted for S. aureus isolates. Ninety percent of Arcobacter spp isolates were susceptible to ciprofloxacin, 85% to gentamicin, and pefloxacin, 70% to chloramphenicol and 90% were resistant to amoxicillin, 85% to augumentin and 80% to streptomycin. Hundred percent of E. coli isolates were susceptible to ciprofloxacin, pefloxacin, 95% to gentamicin and 100% were resistant to streptomycin, 85 % resistant to amoxicillin, augumentin, while 100% of S. aureus isolates were susceptible to trimethoprim sulphamethoxazole, 90% susceptible to gentamicin, 80% to streptomycin and 100% of the S.aureus isolates were resistant to ampliclox. Conclusion: The bacteriological status of chicken carcass revealed high contamination with Arcobacter, E coli and S. aureus with varying degree of antibiotic resistance therefore, improvement in meat processing procedures and strict hygiene measures towards reduction of these pathogens in food products should be encouraged.

scholarly journals Bacterial Analysis and Survey of the Street Food of Kathmandu in Relation to Child Health

2015 ◽  
Vol 26 ◽  
pp. 1-9
Author(s):  
R Tuladhar ◽  
Anjana Singh
Keyword(s):  
Bacterial Contamination ◽  
Enterobacter Aerogenes ◽  
Food Samples ◽  
Hygiene Practice ◽  
Street Vendors ◽  
Street Food ◽  
E Coli ◽  
Food Borne ◽  
Food Borne Illness ◽  
Dominant Bacteria

Analysis of street foods of Kathmandu for bacterial contamination was performed in 12 different street foods. The surveillance study was carried in 200 children of primary grade from public school and 12 street vendors for the health hygiene and hazards associated with street food. Poor hygiene practice in preparation and handling of street food has been observed in the vendors. The lack of the knowledge in vendors about the source of bacterial contamination and absence of surveillance on street food has subjected street food to the high potential for food borne illness. The inadequate safety measure adopted by the targeted consumers of street food, the children, has augmented the risk associated with street food. All the food samples analyzed were contaminated with bacteria. The mesophilic count was recorded highest in Panipuri while as coliform count was highest in Chana tarkari. The least count of both was observed in Aaloo chop . Highest number of Staphylococccus aureus was found in Kerau (1.5X103cfu/g) and lowest in Momo (8.3 cfu/g). The dominant bacteria contaminating the food was S. aureus followed by Bacillus alvei, Escherichia coli, Enterobacter aerogenes, Bacillus subtilis, Serratia sp., S. saprophyticus. The contaminated hand and clothing of the person who prepare food are the major source of S. aureus. Highest percentage of E. coli found in Panipuri must be due to the use of contaminated water. Chana chatpate and Chana tarkari were the foods found to be contaminated with Salmonella sp. The type of food and the degree of hygiene practice adopted by vendor refl ects the type and magnitude of bacterial contamination. Implementation of hygienic practices in vendors may reduce the contamination of street food and health education of the school children will curtail the incidences of food borne illness. Periodical monitoring of quality of street food will avoid any future outbreaks of bacterial pathogen.J. Nat. Hist. Mus. Vol. 26, 2012: 1-9

scholarly journals TheEscherichia coliO157:H7 Carbon Starvation-Inducible Lipoprotein Slp Contributes to Initial AdherenceIn Vitrovia the Human Polymeric Immunoglobulin Receptor

2018 ◽  
Author(s):  
Christine Fedorchuk ◽  
Indira T. Kudva ◽  
Subhashinie Kariyawasam
Keyword(s):  
Escherichia Coli ◽  
Immunofluorescence Microscopy ◽  
Polymeric Immunoglobulin Receptor ◽  
Wild Type ◽  
Immunoglobulin Receptor ◽  
E Coli ◽  
Data Support ◽  
Food Borne ◽  
Food Borne Illness ◽  
Adherence Mechanism

AbstractEscherichia coliO157:H7 is the most well-studied serotype of enterohemorrhagicE. coli(EHEC) class ofE. coliintestinal pathogens, and is responsible for many outbreaks of serious food-borne illness worldwide each year. Adherence mechanisms are a critical component of its pathogenesis, persistence in natural reservoirs, and environmental contamination.E. coliO157:H7 has a highly effective virulence operon, the Locus of Enterocyte Effacement (LEE), and its encoded intimate adherence mechanism is well characterized. However, factors involved in the preceding initial attachment are not well understood. In this study, we propose a mechanism of initial adherence used byE. coliO157:H7in vitro. We describe a bacterial protein not previously reported to be involved in adherence, Slp, and its interactions with the human host protein polymeric immunoglobulin receptor (pIgR). The human pIgR has previously been shown to act as an adherence receptor for some mucosal pathogens, and is highly expressed in the intestine. Following observation of significant colocalization betweenE. coliO157:H7 and pIgR location on Caco-2 cells, a co-immunoprecipitation (Co-IP) assay using a human recombinant Fc-tagged pIgR protein led to the identification of this protein. Disruption of Slp expression inE. coliO157:H7, through deletion of its encoding geneslp, produced a significant adherence deficiency to Caco-2 cells at early time points associated with initial adherence. Plasmid complementation ofslpfully restored the wild-type phenotype. Furthermore, immunofluorescence microscopy revealed evidence that this interaction is specific to the pathogenic strains ofE. colitested, and not the nonpathogenic strain E. coli K12. Additionally, deletion ofslpresulted in the absence of the corresponding protein band in further Co-IP assays, while the plasmid-encodedslpcomplementation of the deletion mutant strain restored the wild-type pattern. These data support the proposal that Slp directly contributes to initial adherence, with the pIgR protein as its proposed receptor.Author summaryEscherichia coliO157:H7 and other enterohemorrhagicE. coli(EHEC) are responsible for tens of thousands of cases of food-borne illness in the United States each year.E. coliO157:H7 has a particularly effective intimate adherence mechanism. However, the mechanisms of initial adherence, which facilitate attachment and virulence prior to the engagement of intimate adherence, are not well understood. In this study, we describe an initial adherence interaction between theE. coliO157:H7 Slp and the human polymeric immunoglobulin receptor (pIgR) expressed by the human colonic epithelial cell line Caco-2. The relationship was first demonstrated as a significant colocalization between the locations ofE. coliO157:H7 bacterial cells and pIgR protein using immunofluorescence microscopy. TheE. coliO157:H7 Slp protein was identified, and disruption of theslpgene resulted in a severe adherence deficiency to Caco-2 cells during initial adherence. This effect was reversed upon complementation of the Δslpstrain with a plasmid-encodedslpgene, and the constitutive over-expression ofslpresulted in hyper-adherence exceeding that of the wild-typeE. coliO157:H7. These data support the proposition that Slp directly contributes to initial adherence, with the pIgR protein as its proposed receptor.

scholarly journals Persistent Colonization of Sheep byEscherichia coli O157:H7 and Other E. coliPathotypes

2000 ◽  
Vol 66 (11) ◽  
pp. 4926-4934 ◽  
Author(s):  
N. A. Cornick ◽  
S. L. Booher ◽  
T. A. Casey ◽  
H. W. Moon
Keyword(s):  
Escherichia Coli ◽  
Young Adult ◽  
Shiga Toxin ◽  
The Other ◽  
E Coli ◽  
Adult Sheep ◽  
Food Borne ◽  
Food Borne Illness ◽  
Byescherichia Coli ◽  
Frequency Magnitude

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) is an important cause of food-borne illness in humans. Ruminants appear to be more frequently colonized by STEC than are other animals, but the reason(s) for this is unknown. We compared the frequency, magnitude, duration, and transmissibility of colonization of sheep by E. coli O157:H7 to that by other pathotypes of E. coli. Young adult sheep were simultaneously inoculated with a cocktail consisting of two strains of E. coli O157:H7, two strains of enterotoxigenic E. coli (ETEC), and one strain of enteropathogenic E. coli. Both STEC strains and ETEC 2041 were given at either 107 or 1010CFU/strain/animal. The other strains were given only at 1010 CFU/strain. We found no consistent differences among pathotypes in the frequency, magnitude, and transmissibility of colonization. However, the STEC strains tended to persist to 2 weeks and 2 months postinoculation more frequently than did the other pathotypes. The tendency for persistence of the STEC strains was apparent following an inoculation dose of either 107 or 1010 CFU. One of the ETEC strains also persisted when inoculated at 1010 CFU. However, in contrast to the STEC strains, it did not persist when inoculated at 107 CFU. These results support the hypothesis that STEC is better adapted to persist in the alimentary tracts of sheep than are other pathotypes ofE. coli.

scholarly journals Microbial contamination in industrial tofu

2017 ◽  
Vol 47 (3) ◽  
Author(s):  
Thaís Teresa Brandão Cavalheiro Ribeiro ◽  
Géssica Costa ◽  
Marisa da Costa
Keyword(s):  
Bacillus Cereus ◽  
Microbial Contamination ◽  
Microbiological Quality ◽  
Human Consumption ◽  
Microbial Quality ◽  
Porto Alegre ◽  
E Coli ◽  
Food Borne ◽  
Food Borne Illness

ABSTRACT: This study aimed to evaluate the microbiological quality of tofu sold in supermarkets in Porto Alegre/Brazil. Bacteria counts were performed for Bacillus cereus , mesophilic, coliforms and Staphylococcus coagulase positive and negative. The presence of Listeria sp. was also evaluated. Two different brands of tofu (A and B) were collected, one lot per month, for six months. Five samples from each lot were analyzed. All lots presented mesophilic aerobic counts above 4.3x105CFU g-1. Four of the six lots from brand A and all lots from brand B showed E. coli and/or Staphylococcus coagulase positive counts above the Brazilian law accepted limits. The Staphylococcus coagulase negative counts were higher than those of coagulase positive in all lots. In all lots where Staphylococcus coagulase positive counts were above the legal limit, there were counts of coagulase negative above 104CFU g-1. B. cereus and Listeria sp. were not found in either brand. The majority of lots of brand A and all lots of brand B were unsuitable for human consumption. Our results showed that there are problems in tofu manufacturing in both industries analyzed. There is a need of improvement on its microbial quality to avoid problems of food-borne illness, and finally the need of a better control by the Brazilian inspection services.

Adherence of enterohemorrhagic Escherichia coli in a beef system

1995 ◽  
Vol 53 ◽  
pp. 1022-1023
Author(s):  
T. S. Schwach ◽  
E. A. Zottola
Keyword(s):  
Escherichia Coli ◽  
Food System ◽  
Enterohemorrhagic Escherichia Coli ◽  
Frozen Ground ◽  
Internal Organs ◽  
Growth Environment ◽  
E Coli ◽  
Food Borne ◽  
Food Borne Illness ◽  
Pure Cultures

Microbiologists have traditionally studied pure cultures growing in laboratory media. Food microbiologists, interested in interactions between the food system, pathogen, and host have tried to extrapolate information in the same manner. However, clinical isolates readily lose virulence characteristics when repeatedly subcultured into laboratory media. Expression of many virulence factors, such as fimbriae, extracellular polymers and outer membrane adhesins are affected by growth environment; an environment which encompasses not only nutrient availability and growth temperature, but also physical surroundings, moisture, oxygen and pH levels, and the presence of competitive flora. The ability of an organism to adhere to a surface is a major virulence factor.Enterohemorrhagic Escherichia coli (EHEC) are one of five groups of enteropathic E. coli which cause intestinal disease world-wide. The most well known of this group, serotype O157:H7, has been implicated in major food-borne illness outbreaks primarily due to the consumption of undercooked hamburgers. They are found in the intestinal tracts of cattle, feces, hanging carcasses, and frozen ground beef. E. coli O157:H7 adheres to large intestinal epithelium with characteristic lesions and produces verocytoxins which damage internal organs, such as the kidney.

Destruction of Escherichia coli O157:H7 and Salmonella typhimurium in Lebanon Bologna by Interaction of Fermentaron pH, Heating Temperature, and Time

1998 ◽  
Vol 61 (2) ◽  
pp. 152-157 ◽  
Author(s):  
KAMESWAR R. ELLAJOSYULA ◽  
STEPHANIE DOORES ◽  
EDWARD W. MILLS ◽  
RICHARD A. WILSON ◽  
RAMASWAMY C. ANANTHESWARAN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Heating Temperature ◽  
Enterohemorrhagic Escherichia Coli ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Food Borne ◽  
Recent Outbreak ◽  
Food Borne Illness ◽  
Effects Of Ph

Fermented meats have caused food-borne illness due to enterohemorrhagic Escherichia coli. Consumption of Lebanon bologna was epidemiologically associated with a recent outbreak of salmonellosis. The present study was conducted to determine the effects of pH (after the fermentation step), final heating temperature, and time on destruction of E. coli O157:H7 and Salmonella typhimurium in Lebanon bologna. Raw Lebanon bologna mix was inoculated with either of the pathogens (ca. 108 CFU/g) and fermented for 12 h at 80°F (26.7°C) and then at 100°F (37.8°C) until the pH reached either 5.2 or 4.7. The mix was then heated to 110,115, or 120°F (43.3, 46.1, or 48.9°C). The bologna was sampled at various times, decimally diluted, and plated on either McConkey sorbitol agar or XLD agar to enumerate E. coli O157:H7 and S. typhimurium, respectively. Fermentation alone reduced populations of both pathogens by <2 log units and heating alone reduced populations of E. coli O157:H7 by < 3 log units. A combination of fermenting to either pH 5.2 or 4.7, followed by heating at 110°F (43.3°C) for 20 h, 115°F (46.1°C) for 10 h, or 120°F (48.9°C) for 3 h reduced populations of both pathogens by >7 log units. Overall, S. typhimurium cells were either equally or significantly less resistant (P < 0.01) than cells of E. coli O157:H7. Significant interactions (P < 0.01) among the three factors for the destruction of E. coli O157:H7 were observed. A process-specific regression equation was developed to predict the destruction of E. coli O157:H7 in Lebanon bologna.

Bacterial contamination of raw vegetables, vegetable-related water and river water in Ho Chi Minh City, Vietnam

2008 ◽  
Vol 58 (12) ◽  
pp. 2403-2411 ◽  
Author(s):  
Nguyen Thi Van Ha ◽  
Masaaki Kitajima ◽  
Nguyen Vo Minh Hang ◽  
Koichi Matsubara ◽  
Satoshi Takizawa ◽  
...  
Keyword(s):  
Tap Water ◽  
Ho Chi Minh City ◽  
Microbial Infection ◽  
Food Markets ◽  
E Coli ◽  
Food Borne ◽  
Food Borne Illness ◽  
Animal Excreta ◽  
Local Farmers ◽  
Vegetable Cultivation

The study attempts to identify the potential routes of bacterial infection via consumption of raw vegetables, drinking water and vegetable-related water in Ho Chi Minh City (HCMC). Vegetables in the markets and restaurants had higher total coliforms and E. coli counts than the vegetables at the vegetable cultivation fields. In search of the potential contamination sources, it was found that vegetables are washed in nearby canals after harvesting. Those canals are contaminated with human and animal excreta, which in turn may contaminate the vegetables. At the markets, although the tap water was found to be free of microbes, contaminated and non-contaminated vegetables are mixed and washed in the same bowl, which may bring about further spreading of infectious bacteria. The results of this study suggested that an integrated countermeasure that incorporates reducing microbial contamination of canals, raising the awareness of microbial infection among the local farmers and wholesalers, and providing enough clean water to the food markets should be implemented to reduce the incidence of food-borne illness in HCMC.

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