scholarly journals Infection with verocytotoxin-producing Escherichia coli O157 during a visit to an inner city open farm

2000 ◽  
Vol 125 (3) ◽  
pp. 531-536 ◽  
Author(s):  
P. A. CHAPMAN ◽  
J. CORNELL ◽  
C. GREEN
Keyword(s):  
Escherichia Coli ◽  
Inner City ◽  
Magnetic Beads ◽  
Profile Analysis ◽  
Enrichment Culture ◽  
Phage Type ◽  
Immunomagnetic Separation ◽  
E Coli ◽  
Zoonotic Infections ◽  
Faecal Samples

Two cases of Escherichia coli O157 infection occurred in children after visiting an inner city open farm. Subsequently faecal samples collected from animal pens and samples of composted mixed animal manure and vegetable waste were examined for E. coli O157 by enrichment culture, immunomagnetic separation and culture of magnetic beads to cefixime tellurite sorbitol MacConkey agar. Strains of E. coli O157 were characterized by hybridization with DNA probes for VT1, VT2 and eaeA, plasmid profile analysis, phage typing and pulsed field gel electrophoresis (PFGE). Verocytotoxin-producing E. coli O157 strains were isolated from faecal samples from a cow, a horse, 3 breeds of pigs, 2 breeds of sheep and 2 breeds of goats and from 2 samples of compost which had been processed for 3 months. All strains were phage type 21, hybridized with probes for VT2 and eaeA but not with one for VT1, harboured 92 and 2 kb plasmids and gave indistinguishable banding patterns with PFGE. Although only two culture-confirmed cases of infection had been identified, the farm had over 100 000 visitors per year and so it was closed as a precaution both to allow a thorough investigation and to prevent further cases. The investigation identified many factors which may have contributed to transmission of E. coli O157 infection. Most of these were readily resolved by appropriate corrective measures and as there were no further cases associated with the farm during the ensuing 4 weeks it then re-opened. These cases highlight the risk, especially to young children, of acquiring zoonotic infections during visits to open farms and emphasize the need for adequate guidance and supervision before and during such visits.

scholarly journals A one year study of Escherichia coli O157 in raw beef and lamb products

2000 ◽  
Vol 124 (2) ◽  
pp. 207-213 ◽  
Author(s):  
P. A. CHAPMAN ◽  
C. A. SIDDONS ◽  
A. T. CERDAN MALO ◽  
M. A. HARKIN
Keyword(s):  
Magnetic Beads ◽  
Enrichment Culture ◽  
Immunomagnetic Separation ◽  
Plasmid Profile ◽  
Early Summer ◽  
Phage Typing ◽  
E Coli ◽  
Genes Encoding ◽  
Beef Products ◽  
Peptone Water

Between April 1996 and March 1997 we examined 5093 samples of raw beef and lamb products for the presence of E. coli O157. Samples were purchased from 81 small butchers' shops in south Yorkshire. In March 1997 we also examined five samples of dried mint for the presence of E. coli O157.Strains of E. coli O157 were isolated by enrichment culture in modified buffered peptone water followed by immunomagnetic separation and culture of magnetic beads onto cefixime tellurite sorbitol MacConkey agar. Strains were characterized by phage typing, toxin genotyping and plasmid analysis.Strains of E. coli O157 were isolated from 72 (1·4%) of 5093 samples; it was isolated from 36 (1·1%) of 3216 samples of beef products and from 29 (2·9%) samples of lamb products. The highest prevalence was found in lamb sausages and lamb burgers where E. coli O157 was isolated from 3 (4·1%) of 73 and 18 (3·7%) of 484 samples respectively. Strains of E. coli O157 were isolated most frequently during early summer. Strains of E. coli O157 were also isolated from 2 of 5 samples of dried mint although we did not determine how the mint had become contaminated.All isolates of E. coli O157 were Verocytotoxin-producing as determined by both Vero cell assay and DNA hybridization for the genes encoding Verocytotoxin and all were positive for the eaeA gene. A combination of phage typing, toxin genotyping and plasmid profile subdivided the 72 strains of E. coli isolated into 20 different subtypes, of which 18 were indistinguishable from strains isolated previously from cattle and sheep; of these 18 strains, 8 were indistinguishable from strains isolated from human cases of infection during the study period.

Immunomagnetic Separation and Flow Cytometry for Rapid Detection of Escherichia coli O157:H7

1998 ◽  
Vol 61 (7) ◽  
pp. 812-816 ◽  
Author(s):  
K. H. SEO ◽  
R. E. BRACKETT ◽  
J. F. FRANK ◽  
S. HILLIARD
Keyword(s):  
Escherichia Coli ◽  
Flow Cytometry ◽  
Magnetic Beads ◽  
Fluorescent Antibody ◽  
Potassium Phosphate ◽  
Immunomagnetic Separation ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Natural Flora ◽  
Short Time

A rapid method for detecting Escherichia coli O157:H7 combining immunomagnetic beads (IMB) and flow cytometry was developed. Labeling antigens separated by IMB with fluorescent antibody enabled the detection of <103 CFU bacteria per ml in pure culture. The optimum concentration of magnetic beads for flow cytometry was lower (ca. 105 particles per ml) than that reported for conventional IMB assay (more than 6 × 106 to 8 × 106 particles per ml). Immunomagnetic separation and flow cytometry (IMFC) were evaluated for detecting E. coli O157:H7 in the presence of a competing microorganism and for detecting antibodies in potassium phosphate buffer. The total assay time from separating antigens with IMB to analyzing with flow cytometry was about 1 h. IMFC detected 103 to 104 CFU of E. coli O157:H7 per ml in ground beef enrichment broth and could effectively discriminate between E. coli O157:H7 and competing natural flora. The new assay system provides another approach to separation and detection of low populations of pathogens and shows potential for detecting low concentrations of toxins and other soluble antigens directly from food in a short time.

scholarly journals Immunomagnetic separation as a sensitive method for isolatingEscherichia coliO157 from food samples

1994 ◽  
Vol 113 (1) ◽  
pp. 31-39 ◽  
Author(s):  
D. J. Wright ◽  
P. A. Chapman ◽  
C. A. Siddons
Keyword(s):  
Magnetic Beads ◽  
Phage Type ◽  
Dairy Herd ◽  
Immunomagnetic Separation ◽  
Epidemiological Studies ◽  
Food Samples ◽  
Tween 20 ◽  
Specific Method ◽  
E Coli ◽  
Peptone Water

SUMMARYMinced beef samples inoculated withEscherichia coliO157 were cultured in buffered peptone water supplemented with vancomycin, cefsulodin and cefixime (BPW-VCC) and subcultured to cefixime tellurite sorbitol MacConkey (CT-SMAC) agar both directly and after immunomagnetic separation (IMS) of the organism with magnetic beads coated with an antibody againstE. coliO157 (Dynabeads anti-E. coli0157, Dynal, Oslo).E. coliO157 was recovered from initial inocula of 200 organisms/g by direct subculture and 2 organisms/g by IMS. Twelve strains ofE. coli0157 of different combinations of phage type, H antigen and toxin genotype were all recovered from initial inocula of two organisms/g by IMS. Nonspecific binding of other organisms to the magnetic beads could be reduced by washing of the beads in PBS with Tween-20 0·002–0.005%E. coliO157 was not bound by magnetic coated with an unrelated antibody.During investigation of a dairy herd that was possibly linked to a small outbreak of infection withE. coliO157, the organism was isolated from 2 of 279 forestream milk samples from individual cattle; both isolates were made only by the IMS technique. IMS is rapid, technically simple, and a specific method for isolation ofE. coliO157 and will be useful in epidemiological studies.

scholarly journals Isolation and characterization of enterohaemorrhagic Escherichia coli O157[ratio ]H7 from cattle in Belgium and Poland

2002 ◽  
Vol 129 (1) ◽  
pp. 41-47 ◽  
Author(s):  
A. V. TUTENEL ◽  
D. PIERARD ◽  
J. URADZINSKI ◽  
E. JOZWIK ◽  
M. PASTUSZCZAK ◽  
...  
Keyword(s):  
Phage Type ◽  
Immunomagnetic Separation ◽  
E Coli ◽  
Slaughter Cattle ◽  
Isolation And Characterization ◽  
Enterohaemorrhagic Escherichia Coli ◽  
Faecal Samples ◽  
Peptone Water ◽  
Ferment Lactose

EHEC O157 were isolated from faeces of Belgian and Polish beef slaughter cattle. In Belgium, 1281 faecal samples were analysed by immunomagnetic separation [IMS] after enrichment in buffered peptone water from June 1998 till July 1999. Eighty-one samples (6.3%) were positive for E. coli O157. Phage type 8 was most frequently found. Bulls between 1 and 2 years old, slaughtered in September and October were most frequently found positive. Atypical biochemical features were observed in some isolates: 22 (27%) isolates were urease positive and 1 (1.2%) isolate was unable to ferment lactose. In Poland, 551 faecal samples, taken from January 1999 till December 1999, were examined using exactly the same techniques. Four faecal samples (0.7%) were positive for O157 EHEC, yielding seven phage type 8 isolates. All positive samples were from cattle younger than 2 years. Positive samples occurred in August, September and October.

scholarly journals A 1-year study of Escherichia coli O157 in cattle, sheep, pigs and poultry

1997 ◽  
Vol 119 (2) ◽  
pp. 245-250 ◽  
Author(s):  
P. A. CHAPMAN ◽  
C. A. SIDDONS ◽  
A. T. CERDAN MALO ◽  
M. A. HARKIN
Keyword(s):  
Escherichia Coli ◽  
Magnetic Particles ◽  
Enrichment Culture ◽  
Late Summer ◽  
Immunomagnetic Separation ◽  
E Coli ◽  
Source Of Infection ◽  
The Status ◽  
Peptone Water ◽  
Dairy Animals

Samples of rectal faeces were collected immediately after slaughter from 400 cattle each month for a 1-year period and from 1000 each of sheep, pigs and poultry over the same period. Samples were examined for Escherichia coli O157 by enrichment culture in buffered peptone water with vancomycin, cefixime and cefsulodin followed by immunomagnetic separation and culture of magnetic particles onto cefixime tellurite sorbitol MacConkey agar. E. coli O157 was isolated from 752 (15·7%) of 4800 cattle, 22 (2·2%) of 1000 sheep and from 4 (0·4%) of 1000 pigs, but not from any of 1000 chickens. Of the cattle sampled, 1840 (38·4%) were prime beef animals, 1661 (34·6%) were dairy animals being culled and the status could not be determined for the other 1299 (27%) animals. E. coli O157 was found in 246 (13·4%) of the 1840 beef cattle and 268 (16·1%) of the 1661 dairy cattle. The monthly prevalence of E. coli O157 in cattle was 4·8–36·8% and was at its highest in spring and late summer. Seventeen of the 22 isolates from sheep were also made over the summer period. All E. coli O157 isolates from sheep and 749 (99·6%) of the 752 E. coli O157 isolates from cattle were verocytotoxigenic as determined by Vero cell assay and DNA hybridization, eaeA gene positive, contained a 92 kb plasmid and were thus typical of strains causing infections in man. In contrast isolates from pigs were non-toxigenic, eaeA gene negative and did not contain a 92 kb plasmid and would, therefore, be unlikely to be a source of infection for man.

Isolation and Characterization of Escherichia coli O157:H7 from Retail Meats in Argentina

2001 ◽  
Vol 64 (9) ◽  
pp. 1346-1351 ◽  
Author(s):  
ISABEL CHINEN ◽  
JOSÉ DANIEL TANARO ◽  
ELIZABETH MILIWEBSKY ◽  
LILIANA HAYDEÉ LOUND ◽  
GERMÁN CHILLEMI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Enrichment Culture ◽  
Culture Method ◽  
Immunomagnetic Separation ◽  
Phage Typing ◽  
Escherichia Coli O157 ◽  
Potassium Tellurite ◽  
E Coli ◽  
Isolation And Characterization ◽  
Retail Meats

Between February and May 2000, 279 meat samples were collected from 136 retail stores in Gualeguaychú City, Argentina. Samples were assayed for Escherichia coli O157:H7 by selective enrichment in modified EC broth containing novobiocin, followed by immunomagnetic separation (IMS) and plating onto both sorbitol MacConkey agar supplemented with cefixime and potassium tellurite and a chromogenic medium. Eleven E. coli O157:H7 isolates were detected in 6 (3.8%) of 160 ground beef samples, in 4 (4.8%) of 83 fresh sausages, and in 1 (3.3%) of 30 dry sausages. E. coli O157:H7 was not isolated from five hamburger patties or one barbecue-type fresh sausage assayed. The isolates were tested for virulence-related genes. Ten additional Shiga toxin-producing E. coli (STEC) O157:H7 isolates of food origin, recovered from different locations in Argentina, were included for comparison purposes. All 21 isolates harbored both eae and EHEC-hlyA genes, and 12 (57.1%) encoded stx2/stx2vh-a. The isolates were of phage types 87 (seven strains), 14 (four strains), 4 (three strains), and 26 (one strain). Six strains were nontypable by phage typing. Pulsed-field gel electrophoresis (PFGE) revealed 19 XbaI-PFGE profiles. Fifteen (71%) strains were grouped in four clusters, which shared more than 80% of DNA restriction fragments. The enrichment culture method with IMS was a sensitive procedure to detect E. coli O157:H7 strains in retail meats. Some of the isolates from different stores presented a high clonal relatedness, as determined by XbaI-PFGE and phage typing, and harbored the virulence factors associated with human illness.

scholarly journals Persistence of Escherichia coli O157[ratio ]H7 in dairy cattle and the dairy farm environment

1997 ◽  
Vol 119 (2) ◽  
pp. 251-259 ◽  
Author(s):  
K. RAHN ◽  
S. A. RENWICK ◽  
R. P. JOHNSON ◽  
J. B. WILSON ◽  
R. C. CLARKE ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dairy Cattle ◽  
Environmental Samples ◽  
Phage Type ◽  
Dairy Farm ◽  
E Coli ◽  
Faecal Samples ◽  
One Year ◽  
Culture Negative ◽  
Composite Samples

The persistence of Escherichia coli O157[ratio ]H7 in cattle and the farm environment was investigated on eight Ontario dairy farms positive for E. coli O157[ratio ]H7 in a longitudinal study commenced one year previously. Faecal samples from cows, calves, humans, cats, rodents, wild birds, a composite fly sample and numerous composite and individual environmental samples were cultured and tested for verotoxin-producing E. coli (VTEC). VTEC isolates were serotyped and E. coli O157[ratio ]H7 isolates were phage typed. E. coli O157[ratio ]H7 phage type 34 was isolated from one calf on each of two farms. The same phage type had been isolated on one of these farms 12 months earlier. Most E. coli O157[ratio ]H7-positive animals and farms became culture-negative within 2 and 3 months, respectively. E. coli O157[ratio ]H7 was not isolated from any environmental samples, although evidence of VTEC was found in composite samples from calf feeders (19·1%), calf barn surfaces (18%), cow feeders (14·9%), flies (12·5%), cow barn surfaces (11·3%), and individual milk filters (12·5%). VTEC belonging to 21 non-O157 serotypes were isolated from 24 cows (8·2%), 21 calves (18·3%), 2 cow feeder samples (3·0%), and 1 calf feeder sample (4·8%). Shedding of E. coli O157[ratio ]H7 by infected dairy cattle appears to be transient and persistence of E. coli O157[ratio ]H7 was not demonstrated from the farm environment sites tested.

scholarly journals Occurrence of shigatoxinogenic Escherichia coli O157 in Norwegian cattle herds

1998 ◽  
Vol 120 (1) ◽  
pp. 21-28 ◽  
Author(s):  
L. VOLD ◽  
B. KLUNGSETH JOHANSEN ◽  
H. KRUSE ◽  
E. SKJERVE ◽  
Y. WASTESON
Keyword(s):  
Escherichia Coli ◽  
Vero Cell ◽  
Immunomagnetic Separation ◽  
The Other ◽  
Virulence Plasmid ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Faecal Samples ◽  
Cattle Herds ◽  
Encoding Genes

To investigate if there is a reservoir of Escherichia coli O157 in Norwegian cattle, faecal samples from 197 cattle herds were screened for E. coli O157 by the use of immunomagnetic separation (IMS) and PCR during the 1995 grazing season. Six E. coli O157[ratio ]H-isolates were detected in two herds, one isolate in one and five in the other. The isolates carried the stx1, stx2, and eae genes, and a 90 MDa virulence plasmid. They were toxinogenic in a Vero cell assay. From 57 other herds, 137 faecal samples were positive for stx1 and/or stx2 genes detected by PCR run directly on IMS-isolated material. Among these samples, stx2 were the most widely distributed toxin encoding genes. No difference was found among milking cows and heifers in the rate of stx1 and/or stx2 in positive samples.

Surface and Internalized Escherichia coli O157:H7 on Field-Grown Spinach and Lettuce Treated with Spray-Contaminated Irrigation Water

2010 ◽  
Vol 73 (6) ◽  
pp. 1023-1029 ◽  
Author(s):  
MARILYN C. ERICKSON ◽  
CATHY C. WEBB ◽  
JUAN CARLOS DIAZ-PEREZ ◽  
SHARAD C. PHATAK ◽  
JOHN J. SILVOY ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Irrigation Water ◽  
Enrichment Culture ◽  
Field Studies ◽  
Plate Count ◽  
Escherichia Coli O157 ◽  
Adaxial Side ◽  
Abaxial Side ◽  
E Coli ◽  
Contaminated Irrigation Water

Numerous field studies have revealed that irrigation water can contaminate the surface of plants; however, the occurrence of pathogen internalization is unclear. This study was conducted to determine the sites of Escherichia coli O157:H7 contamination and its survival when the bacteria were applied through spray irrigation water to either field-grown spinach or lettuce. To differentiate internalized and surface populations, leaves were treated with a surface disinfectant wash before the tissue was ground for analysis of E. coli O157:H7 by direct plate count or enrichment culture. Irrigation water containing E. coli O157:H7 at 102, 104, or 106 CFU/ml was applied to spinach 48 and 69 days after transplantation of seedlings into fields. E. coli O157:H7 was initially detected after application on the surface of plants dosed at 104 CFU/ml (4 of 20 samples) and both on the surface (17 of 20 samples) and internally (5 of 20 samples) of plants dosed at 106 CFU/ml. Seven days postspraying, all spinach leaves tested negative for surface or internal contamination. In a subsequent study, irrigation water containing E. coli O157:H7 at 108 CFU/ml was sprayed onto either the abaxial (lower) or adaxial (upper) side of leaves of field-grown lettuce under sunny or shaded conditions. E. coli O157:H7 was detectable on the leaf surface 27 days postspraying, but survival was higher on leaves sprayed on the abaxial side than on leaves sprayed on the adaxial side. Internalization of E. coli O157:H7 into lettuce leaves also occurred with greater persistence in leaves sprayed on the abaxial side (up to 14 days) than in leaves sprayed on the adaxial side (2 days).

An Improved Screening Method for the Detection and Isolation of Escherichia coli 0157:H7 From Meat, Incorporating the 3M Petrifilm™ Test Kit - HEC - for Hemorrhagic Escherichia coli 0157:H7

1990 ◽  
Vol 53 (11) ◽  
pp. 936-940 ◽  
Author(s):  
ANITA J. G. OKREND ◽  
BONNIE E. ROSE ◽  
RICHARD MATNER
Keyword(s):  
Escherichia Coli ◽  
Screening Program ◽  
Enrichment Culture ◽  
Screening Method ◽  
Meat Sample ◽  
E Coli ◽  
Enrichment Cultures ◽  
Poultry Products ◽  
Test Kit ◽  
Cooked Meat

A screening method was devised incorporating a commercially available reactive disc blot ELISA for Escherichia coli 0157 antigen, into a cultural screening program for the isolation of E. coli 0157:H7 from meat and poultry products. The method includes the inoculation of a raw or cooked meat sample into an enrichment broth, incubation with shaking at 37°C for 6 to 8 h, followed by inoculation of 3M Petrifilm™ E. coli Count plates with dilutions of the enrichment culture. The Petrifilm plates were incubated at 42°C for 18 h and tested for the presence of the 0157 antigen. The enrichment cultures were reincubated static at 35°C after the initial shaken incubation. Isolation was attempted from the positive Petrifilm plates by both a direct picking and streaking method and by the 3M Prompt™ isolation method. Isolation also was attempted from the 24-h enrichment cultures by spread plating serial dilutions on 150 × 15 mm MacConkey sorbitol agar (MSA) and MSA with 5-bromo-4-chloro-3-indoxyl-β-D-glucuronic acid cyclohexylammonium salt (BCIG). This fast and efficient screening procedure identifies negative and presumptive positive samples in 26–28 h. Isolation and confirmation of the presumptive positive isolates require an additional 3 to 4 d.

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