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detection of verocytotoxin from stool and serological testing of patients with diarrhea caused by escherichia coli o157 : h7.the detection of verocytotoxin (vt) in stool and measurement of antibodies against vt and three antigens (unheated-antigen, lps, and flagellin) of escherichia coli o157 : h7 in the serum of patients with diarrhea were examined. five of 14 inpatients during an outbreak had fecal vt2 in stool taken within 5 days of onset to hospitalization. among these 5, 3 of them also had fecal vt-producing e. coli (vtec) serotype o157 : h7, whereas the other 2 did not. in the passive hemagglutination (pha) test ...19938502176
microbiology of fresh and restructured lamb meat: a review.microbiology of meats has been a subject of great concern in food science and public health in recent years. although many articles have been devoted to the microbiology of beef, pork, and poultry meats, much less has been written about microbiology of lamb meat and even less on restructured lamb meat. this article presents data on microbiology and shelf-life of fresh lamb meat; restructured meat products, restructured lamb meat products, bacteriology of restructured meat products, and important ...19957576150
isolation of escherichia coli o157:h7 from retail fresh meats and poultry.a total of 896 samples of retail fresh meats and poultry was assayed for escherichia coli serogroup o157:h7 by a hydrophobic grid membrane filter-immunoblot procedure developed specifically to isolate the organism from foods. the procedure involves several steps, including selective enrichment, filtration of enrichment culture through hydrophobic grid membrane filters, incubation of each filter on nitrocellulose paper on selective agar, preparation of an immunoblot (by using antiserum to e. coli ...19873322190
characterization of an rtx toxin from enterohemorrhagic escherichia coli o157:h7.a hemolytic determinant of enterohemorrhagic escherichia coli o157:h7 is encoded on a 90-kbp plasmid (po157). this enterohemorrhagic e. coli toxin (ehx) is a newly described rtx cytotoxin. the prototype rtx toxin is the e. coli hemolysin (hly) associated with extraintestinal e. coli infections. we expressed ehx from e. coli k-12 strains harboring either psk3, a po157 derivative marked with tn801 unlinked to ehx, or a recombinant plasmid containing an 11.9-kbp subclone (peo40) of psk3. the ehx ac ...19968557336
escherichia coli o157:h7 in microbial flora of sheep.we found naturally occurring, potentially virulent escherichia coli o157:h7 strains in sheep. the incidence of e. coli o157:h7 was transient and ranged from 31% of sheep in june to none in november. the use of a sensitive culture technique and the choice of the proper sampling season were both essential for detecting this bacterium in sheep. dna hybridizations showed that 80% of the e. coli o157:h7 isolates had at least two of the shiga-like toxin types i or ii or the attaching-effacing lesion g ...19968789031
effect of diet on the shedding of escherichia coli o157:h7 in a sheep model.the purpose of this study was to develop a sheep model to investigate reproduction, transmission, and shedding of escherichia coli o157:h7 in ruminants. in addition, we investigated the effect of diet change on these parameters. six groups of twin lambs given oral inoculations of 10(5) or 10(9) cfu of e. coli o157:h7 and their nondosed mothers were monitored for colonization by culture of fecal samples. a modified selective-enrichment protocol that detected e. coli o157:h7 at levels as low as 0. ...19957747956
evaluation of dietary influences on escherichia coli o157:h7 shedding by sheep.the effect of diet, an abrupt diet change, and fasting on the shedding of escherichia coli o157:h7 was investigated with experimentally inoculated sheep as a ruminant model. sheep were fed a grass hay diet (g), which was low in protein and digestible energy and high in fiber, or a mixture of corn and pelleted alfalfa (c), which was high in protein and digestible energy and low in fiber. after a single oral inoculation of e. coli o157:h7, all the animals shed fecal e. coli o157:h7. however, sheep ...19979327551
an outbreak of escherichia coli o157:h7 infections associated with leaf lettuce consumption.in july 1995, 40 montana residents were identified with laboratory-confirmed escherichia coli o157:h7 infection; 52 residents had bloody diarrhea without laboratory confirmation. the median age of those with laboratory-confirmed cases was 42 years (range, 4- 86); 58% were female. thirteen patients were hospitalized, and 1 developed hemolytic-uremic syndrome. a case-control study showed that 19 (70%) of 27 patients but only 8 (17%) of 46 controls reported eating purchased (not home-grown) leaf le ...19989607837
characterization of escherichia coli o157:h7 and other shiga toxin-producing e. coli serotypes isolated from sheep.the isolation and characterization of escherichia coli o157:h7 and non-o157 shiga toxin-producing e. coli (stec) strains from sheep are described. one flock was investigated for e. coli o157:h7 over a 16-month period that spanned two summer and two autumn seasons. variation in the occurrence of e. coli o157:h7-positive sheep was observed, with animals being culture positive only in the summer months but not in the spring, autumn, or winter. e. coli o157:h7 isolates were distinguished by pulsed-f ...19979157149
identification of listeria monocytogenes from unpasteurized apple juice using rapid test kits.a microbiological survey of 50 retail juices was conducted in the fall of 1996. these juices were analyzed for listeria monocytogenes, escherichia coli o157:h7, salmonella, coliforms, fecal coliforms, and ph. two unpasteurized juices were positive for l. monocytogenes: an apple juice and an apple raspberry blend with a ph of 3.78 and 3.75, respectively. three l. monocytogenes isolates were characterized. the colonies were typical for listeria sp. on oxford and lithium chloride-phenylethanol-moxa ...19989766077
analysis of escherichia coli o157:h7 survival in ovine or bovine manure and manure slurry.farm animal manure or manure slurry may disseminate, transmit, or propagate escherichia coli o157:h7. in this study, the survival and growth of e. coli o157:h7 in ovine or bovine feces under various experimental and environmental conditions were determined. a manure pile collected from experimentally inoculated sheep was incubated outside under fluctuating environmental conditions. e. coli o157:h7 survived in the manure for 21 months, and the concentrations of bacteria recovered ranged from <10( ...19989726855
isolation of escherichia coli o157:h7 from some egyptian foods.a survey was done in middle egypt to determine if escherichia coli o157:h7 was present in 175 samples of raw ground beef, chicken, lamb and unpasteurized milk. the pathogen was detected in 3 of 50 (6%) beef samples, 2 of 50 (4%) chicken samples, 1 of 25 (4%) lamb samples and 3 of 50 (6%) milk samples obtained from slaughterhouses, supermarkets and farmer's homes.19968796444
comparative studies of magnetic particle-based solid phase fluorogenic and electrochemiluminescent immunoassay.two solid phase immunoassays, an electrochemiluminescent immunoassay (eclia) and a magnetic particle fluorogenic immunoassay (mpfia) were evaluated and compared for bacterial detection. briefly, the eclia is based on a redox reaction between ruthenium (ii)-trisbipyridyl ru[(bpy)3]2+ labeled antibody and the excess of tripropylamine, which generates photons. the entire reaction is carried on the near surface area between the spherical magnetic beads and an anode electrode. the detectable bacteria ...19989819118
antibiotic resistance of escherichia coli o157:h7 and o157:nm isolated from animals, food, and humans.antibiotic resistance was determined for 118 e. coli o157:h7 and 7 o157:nm isolates from animals, foods, and humans. among the 125 isolates, 30 (24%) were resistant to at least one antibiotic and 24 (19%) were resistant to three or more antibiotics. cattle isolates had the highest rate (34%) of antibiotic resistance. the seven resistant food isolates were all from ground beef. the most frequent resistance type overall was streptomycin-sulfisoxazole-tetracycline, which accounted for over 70% of t ...19989829195
ruminant gastrointestinal cell proliferation and clearance of escherichia coli o157:h7.human infections with escherichia coli o157:h7 cause hemorrhagic colitis that can progress to a life-threatening sequelae. the most common mode of disease transmission is ingestion of contaminated bovine food products, and it is well established that e. coli o157:h7 is a transient member of the bovine microbiota. however, the conditions that induce acquisition and subsequent clearance of this bacterium from the ruminant gastrointestinal tract (git) are not understood. evidence that the rates of ...200010858188
health risks associated with unpasteurized goats' and ewes' milk on retail sale in england and wales. a phls dairy products working group study.a pilot study to determine the microbiological quality of unpasteurized milk from goats and ewes sampled from farm shops, health food shops, and other retail premises found that 47%, (47/100) of goats' and 50% (13/26) of ewes' milk samples failed the standards prescribed by the dairy products (hygiene) regulations 1995. in addition, staphylococcus aureus, haemolytic streptococci or enterococci, were present in excess of 10(2) c.f.u./ml in 9 (7 %) 2 (2 %) and 19 (15%) samples, respectively. salmo ...199910459642
biocontrol of escherichia coli o157 with o157-specific bacteriophages.escherichia coli o157 antigen-specific bacteriophages were isolated and tested to determine their ability to lyse laboratory cultures of escherichia coli o157:h7. a total of 53 bovine or ovine fecal samples were enriched for phage, and 5 of these samples were found to contain lytic phages that grow on e. coli o157:h7. three bacteriophages, designated kh1, kh4, and kh5, were evaluated. at 37 or 4 degrees c, a mixture of these three o157-specific phages lysed all of the e. coli o157 cultures teste ...199910473373
[enterohemorrhagic escherichia coli o157:h7 infection].infections in the digestive tract are due to multiple organism, which cause different syndromes. escherichia coli o157:h7, already identified as a human pathogen in 1982, has been recognised as a major public health issue, being responsible for sporadic and epidemic cases of haemorrhagic colitis, often associated, in children and elderly, with the haemolytic uraemic syndrome. e. coli o157:h7 infection may occur everywhere, but is more frequent in north europe, canada, usa, argentina and japan, w ...199910608152
attaching and effacing lesions caused by escherichia coli o157:h7 in experimentally inoculated neonatal lambs.four 6-day-old conventionally reared lambs were inoculated orally with a total of 10(9) cfu comprising equal numbers of four enterohaemorrhagic escherichia coli (ehec) o157:h7 strains. all animals remained clinically normal. tissues were sampled under terminal anaesthesia at 12, 36, 60 and 84 h post inoculation (hpi). ehec o157:h7 was cultured from most gastrointestinal tract sites. small, sparse attaching and effacing (ae) lesions were found in the caecum at 12 and 36 hpi and in the terminal co ...200111549176
[using multiplex pcr for the detection of virulence genes in escherichia coli o157:h7].to detect and characterize the virulence genes in e. coli o157:h7 isolated from various reservoir in six areas of jiangsu province.200011860822
behavior of escherichia coli o157:h7 during the manufacture and ripening of feta and telemes cheeses.pasteurized whole ewe's and cow's milk was used in the manufacture of feta end telemes cheeses, respectively, according to standard procedures. in both cases, the milk had been inoculated with escherichia coli o157:h7 at a concentration of ca. 5.1 log cfu/ml and with thermophilic or mesophilic starter cultures at a concentration of ca. 5.3 to 5.6 log cfu/ml. in the first 10 h of cheesemaking, the pathogen increased by 1.18 and 0.82 log cfu/g in feta cheese and by 1.56 and 1.35 log cfu/ g in tele ...200211952208
gastrointestinal tract location of escherichia coli o157:h7 in ruminants.experimentally inoculated sheep and cattle were used as models of natural ruminant infection to investigate the pattern of escherichia coli o157:h7 shedding and gastrointestinal tract (git) location. eighteen forage-fed cattle were orally inoculated with e. coli o157:h7, and fecal samples were cultured for the bacteria. three distinct patterns of shedding were observed: 1 month, 1 week, and 2 months or more. similar patterns were confirmed among 29 forage-fed sheep and four cannulated steers. to ...200211976097
[surveillance of escherichia coli o157:h7 among animals in jiangsu province in 1999].to understand the escherichia coli o157:h7 carrier rate of host animals and the toxic gene of the strains in different areas in jiangsu province.200212015089
selection of recently isolated colicinogenic escherichia coli strains inhibitory to escherichia coli o157:h7.escherichia coli strains were screened for their ability to inhibit e. coli o157:h7. an initial evaluation of 18 strains carrying previously characterized colicins determined that only colicin e7 inhibited all of the e. coli o157:h7 strains tested. a total of 540 strains that had recently been isolated from humans and nine different animal species (cats, cattle, chickens, deer, dogs, ducks, horses, pigs, and sheep) were tested by a flip-plating technique. approximately 38% of these strains were ...200212233846
experimental and field studies of escherichia coli o157:h7 in white-tailed deer.studies were conducted to evaluate fecal shedding of escherichia coli o157:h7 in a small group of inoculated deer, determine the prevalence of the bacterium in free-ranging white-tailed deer, and elucidate relationships between e. coli o157:h7 in wild deer and domestic cattle at the same site. six young, white-tailed deer were orally administered 10(8) cfu of e. coli o157:h7. inoculated deer were shedding e. coli o157:h7 by 1 day postinoculation (dpi) and continued to shed decreasing numbers of ...200111229913
escherichia coli o157:h7 in faeces from cattle, sheep and pigs in the southwest part of norway during 1998 and 1999.during a 2-year period from january 1998 to december 1999, intestinal content from 1541 cattle, 665 sheep and 1976 pigs were analysed for escherichia coli o157:h7 using the immunomagnetic separation procedure. the animals originated from 848, 605 and 832 herds from the southwest part of norway, respectively. e. coli o157:h7 was present in three samples from cattle from different herds, giving a herd prevalence of 0.35% and an animal prevalence of 0.19%. from pigs, e. coli o157:h7 was isolated fr ...200111393688
experimental infection of six-month-old sheep with escherichia coli o157:h7. 200111394800
reduction of fecal shedding of enterohemorrhagic escherichia coli o157:h7 in lambs by feeding microbial feed supplement.enterohemorrhagic escherichia coli o157:h7, an emerging food-borne pathogen, has been implicated in several outbreaks in the us. ruminants, including cattle, sheep and deer are reservoirs of e. coli o157:h7 and fecal shedding of the pathogen forms the vehicle of entry into the human food chain. we studied the efficacy of lactobacillus acidophilus, streptococcus faecium, a mixture of l. acidophilus and s. faecium and a mixture of l. acidophilus, s. faecium, lactobacillus casei, lactobacillus ferm ...200111163713
production of attaching-effacing lesions in ligated large intestine loops of 6-month-old sheep by escherichia coli o157:1h7.shiga-toxigenic escherichia coli o157:h7 (stec o157:h7) is associated with potentially fatal human disease, and a persistent reservoir of the organism is present in some farm animal species, especially cattle and sheep. the mechanisms of persistent colonisation of the ruminant intestine by stec o157:h7 are poorly understood but may be associated with intimate adherence to eukaryotic cells. intimate adherence, as evidenced by induction of attaching-effacing (ae) lesions by stec o157, has been obs ...200212358066
escherichia coli o157:h7 populations in sheep can be reduced by chlorate supplementation.ruminant animals are a natural reservoir of the foodborne pathogen escherichia coli o157:h7. some foodborne pathogens (e.g., e. coli) are equipped with a nitrate reductase that cometabolically reduces chlorate. the intracellular reduction of chlorate to chlorite kills nitrate reductase-positive bacteria; however, species that do not reduce nitrate are not affected by chlorate. therefore, it has been suggested that ruminants be supplemented with chlorate prior to shipment for slaughter in order t ...200312597476
persistence of escherichia coli o157:h7 in experimentally infected swine.these experiments determined the ability of escherichia coli o157:h7 to colonize and persist in pigs simultaneously inoculated with other pathogenic e. coli strains. three-months-old pigs were inoculated with a mixture of five e. coli strains. the mixture included two shiga toxigenic e. coli (stec) o157:h7 strains, two enterotoxigenic e. coli (etec) strains and one enteropathogenic e. coli (epec) strain. a high dose mixture with all five strains at 10(10)cfu/animal (cfu: colony forming units) an ...200212223164
isolation from a sheep of an attaching and effacing escherichia coli o115:h- with a novel combination of virulence factors.attaching and effacing (ae) lesions were observed in the caecum, proximal colon and rectum of one of four lambs experimentally inoculated at 6 weeks of age with escherichia coli o157:h7. however, the attached bacteria did not immunostain with o157-specific antiserum. subsequent bacteriological analysis of samples from this animal yielded two e. coli o115:h(-) strains, one from the colon (co) and one from the rectum (rc), and those bacteria forming the ae lesions were shown to be of the o115 sero ...200212466401
variation in the persistence of escherichia coli o157:h7 in experimentally inoculated 6-week-old conventional lambs.six-week-old lambs were inoculated orally with 10(9) cfu of an antibiotic-resistance marked four-strain mixture of enterohaemorrhagic escherichia coli (ehec) o157:h7 to investigate faecal excretion and intestinal colonisation. in the first experiment, three e. coli o157:h7 isolates were not detected in the faeces of any lambs beyond day 8 post inoculation (pi), or from any of the tissues derived from inoculated animals. one strain, 140065 nal(r), was isolated from the caecum and colon of one lam ...200212466400
persistent colonization of sheep by escherichia coli o157:h7 and other e. coli pathotypes.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 ...200011055945
effect of feeding the ionophores monensin and laidlomycin propionate and the antimicrobial bambermycin to sheep experimentally infected with e. coli o157:h7 and salmonella typhimurium.escherichia coli o157:h7 and salmonella are widely recognized as important agents of foodborne disease with worldwide distribution. the use of ionophores in feeding growing ruminants is widespread in the united states and has attracted recent interest due to the apparent temporal relationship between initial ionophore use and the increase in human e. coli o157:h7 cases. two experiments were conducted to evaluate the effects of short-term feeding of ionophores on fecal shedding, intestinal concen ...200312643501
isolation of a rare escherichia coli o157:h7 strain from farm animals in greece.a strain of escherichia coli o157:h7 was isolated from goat faeces during a surveillance study on the prevalence of this serotype of e. coli in farm animals in greece. three hundred and fifty one faecal samples were collected from goat, sheep and cattle breeding farms in the area of epirus, northwestern greece. the e. coli o157:h7 isolate was nonsorbitol-fermenter, produced only vt2 and showed a beta-glucuronidase positive activity, a rather unusual biochemical feature for the e. coli o157:h7 se ...200415001315
potentiation of c1 esterase inhibitor by stce, a metalloprotease secreted by escherichia coli o157:h7.the complement system is an essential component of host defense against pathogens. previous research in our laboratory identified stce, a metalloprotease secreted by escherichia coli o157:h7 that cleaves the serpin c1 esterase inhibitor (c1-inh), a major regulator of the classical complement cascade. analyses of stce-treated c1-inh activity revealed that surprisingly, stce enhanced the ability of c1-inh to inhibit the classical complement-mediated lysis of sheep erythrocytes. stce directly inter ...200415096536
mutation of toxb and a truncated version of the efa-1 gene in escherichia coli o157:h7 influences the expression and secretion of locus of enterocyte effacement-encoded proteins but not intestinal colonization in calves or sheep.enterohemorrhagic escherichia coli (ehec) strains comprise a broad group of bacteria, some of which cause attaching and effacing (ae) lesions and enteritis in humans and animals. non-o157:h7 ehec strains contain the gene efa-1 (referred to in previous publications as efa1), which influences adherence to cultured epithelial cells. an almost identical gene in enteropathogenic e. coli (lifa) mediates the inhibition of lymphocyte proliferation and proinflammatory cytokine synthesis. we have shown pr ...200415322038
diarrhea incidence and farm-related risk factors for escherichia coli o157:h7 and campylobacter jejuni antibodies among rural children.serum samples were obtained from 215 farm-resident children and 396 non-farm-resident children living in a defined rural wisconsin population. antibodies to campylobacter jejuni and escherichia coli o157:h7 lipopolysaccharide (o157 lps) immunoglobulin g were measured, and the incidence of clinic visits for diarrheal illness was determined. risk factors were assessed in a telephone interview. there were 363 children (59%) with c. jejuni antibodies (seropositive for >or=2 immunoglobulin classes) a ...200312717628
behaviour of escherichia coli o157:h7 in sour milk, cows' milk yogurt and ewes' milk yogurt. 200212463702
petting zoo-associated escherichia coli 0157:h7--secondary transmission, asymptomatic infection, and prolonged shedding in the classroom. 200415536809
isolation of escherichia coli o157:h7 from foods in greece.the presence of escherichia coli o157:h7 in various foods of animal origin was surveyed in northwestern greece. six hundred samples of unpasteurized cows', ewes' and goats' milk, raw minced meat, uncooked frozen beef hamburgers, sandwiches (containing ham or turkey, mixed vegetable salad with mayonnaise and lettuce), fresh traditional greek pork sausages and swine intestines appropriate for traditional greek kokoretsi were assayed for e. coli serogroup o157:h7 using the standard cultural method ...200312593930
naturally acquired attaching and effacing escherichia coli in sheep.in a series of experiments involving the inoculation of sheep with escherichia coli o157:h7, and subsequent detailed histopathological examination of the intestinal mucosa, attaching-effacing (ae) lesions formed by elements of the natural flora were observed in 18% of animals. these incidental ae lesions typically were small and sparse, and were not associated with clinical disease. it was possible to identify further some of the lesional bacteria, revealing that e. coli o115 had formed lesions ...200515563916
fluctuations in the occurrence of escherichia coli o157:h7 on a norwegian farm*.to describe the distribution of escherichia coli o157:h7 on a sporadically positive dairy farm and on possible contact farms over a one-year period.200515836742
detection, occurrence, and characterization of escherichia coli o157:h7 from raw ewe's milk in spain.a study was carried out in the castilla y león region of spain to investigate the presence of escherichia coli o157:h7 in raw ewe's milk samples collected from several cheese factories during 1 year. all specimens were examined for e. coli o157:h7 by selective enrichment at 41.5 +/- 1.0 degrees c, after both 6 and 22 h of incubation, and then immunomagnetically separated and plated on cefixime-potassium tellurite-sorbitol macconkey agar. no growth was obtained in the enrichment broth after a 6-h ...200616629039
detection of salmonella strains and escherichia coli o157:h7 in feces of small ruminants and their isolation with various media.salmonella strains and escherichia coli o157:h7 were detected in 17 and 5 small ruminants in virginia, respectively, of 287 tested. background microflora interfered with the fecal analysis. the combination of salmonella enzyme immunoassay (eia) detection and xylose-lysine-deoxycholate agar isolation was satisfactory. modifying enrichment to a 1:100 dilution enabled effective e. coli o157:h7 detection by eia and isolation by sorbitol-macconkey agar with cefixime-tellurite.200515812051
biotic and abiotic factors influencing in vitro growth of escherichia coli o157:h7 in ruminant digestive contents.the gastrointestinal tract (git) of ruminants is the main reservoir of enterohemorrhagic escherichia coli, which is responsible for food-borne infections in humans that can lead to severe kidney disease. characterization of biotic and abiotic factors that influence the carriage of these pathogens by the ruminant would help in the development of ecological strategies to reduce their survival in the git and to decrease the risk of contamination of animal products. we found that growth of e. coli o ...200616751525
non-toxigenic escherichia coli o157:h7 strain nctc12900 causes attaching-effacing lesions and eae-dependent persistence in weaned sheep.ruminants are regarded as a primary reservoir for escherichia coli o157:h7, an important human pathogen. intimin, encoded by the locus of enterocyte effacement by e. coli o157:h7 organisms, has been cited as one bacterial mechanism of colonisation of the gastrointestinal tract. to confirm this and to test whether a non-toxigenic e. coli o157:h7 strain would colonise and persist in a sheep model, e. coli o157:h7 strain nctc12900, that lacks shiga toxin (stx) genes, was evaluated for use in a shee ...200314503794
long polar fimbriae contribute to colonization by escherichia coli o157:h7 in vivo.the contribution of long polar fimbriae to intestinal colonization by escherichia coli o157:h7 was evaluated in sheep, conventional pigs, and gnotobiotic piglets. e. coli o157:h7 strains with lpfa1 and lpfa2 mutated were recovered in significantly lower numbers and caused fewer attachment and effacement lesions than the parent strain.200415385526
influence of colostrum deprivation and concurrent cryptosporidium parvum infection on the colonization and persistence of escherichia coli o157 : h7 in young lambs.escherichia coli o157 : h7 and cryptosporidium parvum infections of man have been associated with direct contact with small ruminants. colostrum protects neonates against gastrointestinal pathogens, and orphan lambs, which are common on petting farms, may be deprived of this protection. in a recent study, it was demonstrated that high shedding of e. coli o157 : h7 by an 8-week-old goat kid was associated with coincidental c. parvum infection. furthermore, both pathogens were co-located in the di ...200616772407
effects of ractopamine hcl on escherichia coli o157:h7 and salmonella in vitro and on intestinal populations and fecal shedding in experimentally infected sheep and pigs.the effects of the beta-agonist ractopamine, approved for use in finishing swine and cattle to improve carcass quality and performance, were examined on two important foodborne pathogens, escherichia coli o157:h7 and salmonella. ractopamine, administered to sheep before and after oral inoculation with e. coli o157:h7, increased (p < 0.01) fecal shedding and tended to increase (p = 0.08) cecal populations of the challenge strain. pigs receiving ractopamine in the diet and then experimentally infe ...200616775793
molecular and functional characterization of a toxr-regulated lipoprotein from a clinical isolate of aeromonas hydrophila.human diseases caused by species of aeromonas have been classified into two major groups: septicemia and gastroenteritis. in this study, we reported the molecular and functional characterization of a new virulence factor, toxr-regulated lipoprotein, or taga, from a diarrheal isolate, ssu, of aeromonas hydrophila. the taga gene of a. hydrophila exhibited 60% identity with that of a recently identified stce gene from escherichia coli o157:h7, which encoded a protein (stce) that provided serum resi ...200616790746
shiga-toxigenic escherichia coli o157 in agricultural fair livestock, united states.agricultural fairs exhibiting livestock are increasingly implicated in human shiga-toxigenic escherichia coli o157:h7 (stec o157:h7) outbreaks. to estimate livestock stec o157:h7 prevalence at us fairs, we collected 2,919 fecal specimens at 29 county fairs in 2 states and at 3 state fairs in 2002. fly pools were also collected. stec o157:h7 was isolated from livestock at 31 (96.9%) of 32 fairs, including 11.4% of 1,407 cattle, 1.2% of 1,102 swine, 3.6% of 364 sheep and goats, and 5.2% of 154 fly ...200616704838
application of bacteriophages to control intestinal escherichia coli o157:h7 levels in ruminants.a previously characterized o157-specific lytic bacteriophage kh1 and a newly isolated phage designated sh1 were tested, alone or in combination, for reducing intestinal escherichia coli o157:h7 in animals. oral treatment with phage kh1 did not reduce the intestinal e. coli o157:h7 in sheep. phage sh1 formed clear and relatively larger plaques on lawns of all 12 e. coli o157:h7 isolates tested and had a broader host range than phage kh1, lysing o55:h6 and 18 of 120 non-o157 e. coli isolates teste ...200616885287
intimin facilitates colonization by escherichia coli o157:h7 in adult ruminants.we compared the magnitude and duration of fecal shedding of wild-type escherichia coli o157:h7 to that of an isogenic intimin mutant in young adult cattle and sheep. in both ruminant species, wild-type e. coli o157:h7 was shed in greater numbers and for a longer duration than was the intimin mutant.200211953416
development of a magnetic microplate chemifluorimmunoassay for rapid detection of bacteria and toxin in blood.a magnetic microplate chemifluorimmunoassay (mmcia) is described using an immunomagnetic separation and a fluorescent microplate technique for rapid detection of low-level escherichia coli o157:h7, bacillus subtilis var. niger spores, and staphylococcal enterotoxin type b from whole blood. in general, the mmcia has at least several-fold more sensitivity than the conventional enzyme-linked immunosorbent assay. in addition, the assay sensitivities using direct fluorochrome label as the reporter, o ...19989683505
microbial food borne pathogens. escherichia coli o157:h7.escherichia coli o157:h7 has emerged in the past 20 years as a pathogen of public health importance. although most e. coli are normal flora in the colons of humans and other warm-blooded animals, several strains are capable of causing disease in humans. in recent years, e. coli o157:h7 and other shiga-like toxin-producing strains have been transmitted via foods and caused disease ranging from bloody diarrhea, and in more severe cases, hemolytic uremic syndrome and thrombocytopenic purpura. the r ...19989532666
antimicrobial resistance of shiga toxin (verotoxin)-producing escherichia coli o157:h7 and non-o157 strains isolated from humans, cattle, sheep and food in spain.a total of 722 shiga toxin-producing escherichia coli (stec) isolates recovered from humans, cattle, ovines and food during the period from 1992 to 1999 in spain were examined to determine antimicrobial resistance profiles and their association with serotypes, phage types and virulence genes. fifty-eight (41%) out of 141 stec o157:h7 strains and 240 (41%) out of 581 non-o157 stec strains showed resistance to at least one of the 26 antimicrobial agents tested. stec o157:h7 showed a higher percent ...200515921895
rectal administration of escherichia coli o157:h7: novel model for colonization of ruminants.escherichia coli o157:h7 causes hemorrhagic colitis and life-threatening complications. because healthy cattle are reservoirs for the bacterium, ruminant infection models have applications in analyzing the relationship between cattle and this human pathogen and in testing interventions to reduce or prevent bovine colonization with this bacterium. current approaches often do not reliably mimic natural, long-term bovine colonization with e. coli o157:h7 in older calves and adult animals (ages that ...200415294790
isolation and characterization of a new t-even bacteriophage, cev1, and determination of its potential to reduce escherichia coli o157:h7 levels in sheep.bacteriophage cev1 was isolated from sheep resistant to escherichia coli o157:h7 colonization. in vitro, cev1 efficiently infected e. coli o157:h7 grown both aerobically and anaerobically. in vivo, sheep receiving a single oral dose of cev1 showed a 2-log-unit reduction in intestinal e. coli o157:h7 levels within 2 days compared to levels in the controls.200616957272
public health hazards from small ruminant meat products in europe.foodborne diseases, in particular those related to meat and meat products, have recently become a matter of great public concern. sheep and goat meat can transmit infections and diseases either through handling during preparation procedures or as a result of ingestion by the consumer. the authors highlight the second route of contamination in relation to meat and meat products from small ruminants in european countries. among the most important diseases transmitted by mutton and goat meat, toxop ...19979501355
influence of dietary endophyte (neotyphodium coenophialum)-infected tall fescue (festuca arundinacea) seed on fecal shedding of antibiotic resistance-selected escherichia coli o157:h7 in ewes.the objectives were to determine the effects of short-term feeding of a toxic endophyte (neotyphodium coenophialum)-infected tall fescue seed (festuca arundinacea, cultivar 'kentucky 31') on fecal shedding and intestinal concentrations of escherichia coli o157:h7 and the concentrations of prolactin, cortisol, and nefa in experimentally inoculated ewes. twelve ewes (mean bw = 46 +/- 2 kg) were fed a diet containing either high endophyte-infected (hi-e) or low endophyte-infected (lo-e) tall fescue ...200717178802
the influence of melatonin on growth of e. coli o157:h7 in pure culture and exogenous melatonin on faecal shedding of e. coli o157:h7 in experimentally infected wethers.to determine if exogenous melatonin (mel) influences growth of escherichia coli o157:h7 in pure culture and if mel affects faecal shedding patterns of e. coli o157:h7 or total leucocyte counts in sheep.200616834729
assessing the effect of interventions on the risk of cattle and sheep carrying escherichia coli o157:h7 to the abattoir using a stochastic model.escherichia coli o157:h7 persists in being a threat to food safety. the mechanisms behind the spread of e. coli o157:h7 on the farm are complex and poorly understood. the objective of this study was to apply a monte carlo model, constructed to simulate the propagation of e. coli o157:h7 in cattle and sheep on the farm, to both test the effect of different interventions on the risk of animals carrying e. coli o157:h7 to the abattoir and to develop understanding of the underlying processes, includ ...200717207545
presence of shiga toxin-producing e. coli o157:h7 in a survey of wild artiodactyls.this study was carried out to evaluate the role of wild artiodactyls as reservoirs of escherichia coli o157:h7 for livestock and humans. retroanal mucosal swabs samples from 206 red deer (cervus elaphus), 20 roe deer (capreolus capreolus), 6 fallow deer (dama dama) and 11 mouflon (ovis musimon), collected during the hunting season (autumn-winter) in south-western spain, were screened. samples were pre-enriched in modified buffered peptone water, concentrated by an immunomagnetic separation techn ...200717229534
animal reservoirs of escherichia coli o157:[h7]. 19968857580
environmental regulation and colonization attributes of the long polar fimbriae (lpf) of escherichia coli o157:h7.the ability of escherichia coli o157:h7 to colonize the intestinal epithelia is dependent on the expression of intimin and other adhesins. the chromosome of e. coli o157:h7 carries two loci encoding long polar fimbriae (lpf). these fimbriae mediate adherence to epithelial cells and are associated with colonization of the intestine. in order to increase our knowledge about the conditions controlling their expression and their role in colonization of an animal model, the environmental cues that pr ...200717353147
microbiological characterization of lamb carcasses at commercial processing plants in the united states.although the united states produces 203 million lb (ca. 92.1 kg) of domestic lamb and mutton each year, thorough studies of the microbiological safety during lamb processing are lacking. to address this missing information, a total of 2,548 sponge samples from pelts, preevisceration carcasses, and postintervention carcasses were collected from multiple large commercial lamb processing plants to determine aerobic plate counts, the prevalences of escherichia coli o157:h7, non-o157 shiga toxin-prod ...200717803136
prevalence and molecular characterization of escherichia coli o157:h7 on irish lamb carcasses, fleece and in faeces samples.to determine the prevalence, seasonal variation and virulence characteristics of escherichia coli o157:h7 in lambs presented for slaughter in ireland.200718045425
escherichia coli o157:h7 and non-o157 shiga toxin-producing e. coli in healthy cattle, sheep and swine herds in northern spain.three-hundred and forty-five herds (17 swine, 122 dairy sheep, 124 beef and 82 dairy cattle) were investigated for prevalence of shiga toxin-producing escherichia coli (stec). rectal faecal samples were selectively enriched and then examined by immunodetection techniques (immunomagnetic separation with anti-e. coli o157 dynabeads, immunomagnetic cell separation (ims) and automated enzyme-linked fluorescent immunoassay using vidas) and polymerase chain reaction (pcr) (rfbe and flic genes) to asse ...200818234025
occurrence of shiga toxin-producing escherichia coli in a spanish raw ewe's milk cheese.the aim of the present study was to investigate the occurrence of escherichia coli o157:h7 and other shiga toxin-producing e. coli (stec) in 'castellano' cheese, a non-cooked and hard or semi-hard spanish cheese made from ewe's milk. a total of 83 raw milk cheese samples with different ripening times (2.5, 6 and 12 months) were taken at 30 cheese factories. samples were examined for the presence of stec using in the first stage the association of official analytical chemists (aoac) official meth ...200717428564
outbreak of escherichia coli 0157:h7 related to animal contact at a petting zoo.to determine the cause of an outbreak of escherichia coli 0157:h7 related to animal exposures so that further transmission could be prevented.200218159389
role of intimin-tir interactions and the tir-cytoskeleton coupling protein in the colonization of calves and lambs by escherichia coli o157:h7.intimin facilitates intestinal colonization by enterohemorrhagic escherichia coli o157:h7; however, the importance of intimin binding to its translocated receptor (tir) as opposed to cellular coreceptors is unknown. the intimin-tir interaction is needed for optimal actin assembly under adherent bacteria in vitro, a process which requires the tir-cytoskeleton coupling protein (tccp/espf(u)) in e. coli o157:h7. here we report that e. coli o157:h7 tir mutants are at least as attenuated as isogenic ...200616369035
survival of escherichia coli o157:h7 in the rhizosphere of maize grown in waste-amended soil.to assess whether the persistence of escherichia coli o157:h7 in soil amended with cattle slurry and ovine stomach content waste is affected by the presence of a maize rhizosphere.200717241336
shiga toxin and shiga toxin-encoding phage do not facilitate escherichia coli o157:h7 colonization in sheep.isogenic strains of escherichia coli o157:h7, missing either stx(2) or the entire stx2-encoding phage, were compared with the parent strain for their abilities to colonize sheep. the absence of the phage or of the shiga toxin did not significantly impact the magnitude or duration of shedding of e. coli o157:h7.200717085690
indirect transmission of escherichia coli o157:h7 occurs readily among swine but not among sheep.transmission of escherichia coli o157:h7 among reservoir animals is generally thought to occur either by direct contact between a naïve animal and an infected animal or by consumption of food or water containing the organism. although ruminants are considered the major reservoir, there are two reports of human infections caused by e. coli o157:h7 linked to the consumption of pork products or to the contamination of fresh produce by swine manure. the objective of this study was to determine wheth ...200818310419
zoonoses associated with petting farms and open zoos.the popularity of open farms and petting zoos has increased markedly over the last 5 years, with most children in developed countries now having the opportunity to visit such a facility at some stage in their childhood, either through school or family visits. the open access policy of these establishments allows visitors to be in direct contact with animals such as sheep (lambs), goats, cats (kittens), dogs (puppies), and birds and to have the opportunity to feed such animals. this contact may l ...200818052811
is lack of susceptible recipients in the intestinal environment the limiting factor for transduction of shiga toxin-encoding phages?to determine whether a shiga toxin 2 (stx2)-encoding phage from escherichia coli o157:h7 could be transmitted to commensal e. coli in a ruminant host without adding a specific recipient strain.200818492045
detection and frequency of stx2 gene in escherichia coli o157 and o157:h7 strains isolated from sheep carcasses in shiraz-iran.enterohaemorrhagic escherichia coli constitute a subset of serotypes (e. coli o157 and some other serogroups) of shiga toxin-producing e. coli firmly associated with severe human illnesses like bloody diarrhoea and haemolytic uraemic syndrome. escherichia coli o157:h7 is a zoonotic pathogen. they rarely cause disease in animals, live in the intestines of healthy sheep and ruminants are recognized as their main natural reservoir, so they can contaminate meat during slaughtering practices. the pur ...200818819545
low incidence of foodborne pathogens of concern in raw milk utilized for farmstead cheese production.overall milk quality and prevalence of four target pathogens in raw milk destined for farmstead cheesemaking was examined. raw milk samples were collected weekly from june to september 2006 from 11 farmstead cheese operations manufacturing raw milk cheese from cow's, goat's, and sheep's milk. samples were screened for listeria monocytogenes, staphylococcus aureus, salmonella, and escherichia coli o157:h7 both quantitatively (direct plating) and qualitatively (pcr). overall, 96.8% of samples had ...200818724751
isolation of lactoferrin from milk of different species: calorimetric and antimicrobial studies.lactoferrin (lf) is an iron-binding glycoprotein found in different biological fluids of mammals and in neutrophils. it has been proposed to be involved in many functions, including protection from pathogens. in this work, purification of lactoferrin using an ion-exchange chromatography (sp-sepharose) was attempted for the milk of the following animals: sheep (ovis aries), goat (capra hircus), camel (camelus bactrianus), alpaca (lama pacos), elephant (elephas maximus) and grey seal (halichoerus ...200818387837
prevalence and concentration of verotoxigenic escherichia coli o157:h7 in adult sheep at slaughter from italy.a 1-year study on the animal-level prevalence and concentration of escherichia coli o157 in adult sheep at slaughter was performed, to collect qualitative and quantitative information on the diffusion of the pathogen in adult sheep from italy. a total 533 samples were collected, with a similar distribution in the four seasons. for prevalence estimates, a simple random sampling technique was used. an immuno-magnetic separation technique was used for sample screening, with enumeration of the patho ...200918990195
persistence and metabolic activity of escherichia coli o157:h7 in farm animal faeces.ruminants, and to a lesser extent monogastric farm animals, are known to be natural reservoirs of escherichia coli o157:h7, and contact with contaminated faeces has been linked to human infection. this study used a nontoxigenic, chromosomally marked, lux reporter strain to compare the persistence and activity (bioluminescence) of e. coli o157:h7 over 21 days in the faecal liquor of five farm animals: horse, sheep, cow, pig and piglet. samples were inoculated with the lux e. coli o157:h7 (7.82 lo ...200818715227
bacteriophage isolated from feedlot cattle can reduce escherichia coli o157:h7 populations in ruminant gastrointestinal tracts.escherichia coli o157:h7 can live undetected in the gut of food animals and be spread to humans directly and indirectly. bacteriophages are viruses that prey on bacteria, offering a natural, nonantibiotic method to reduce pathogens from the food supply. here we show that a cocktail of phages isolated from commercial cattle feces reduced e. coli o157:h7 populations in the gut of experimentally inoculated sheep. a cocktail of phages was used in order to prevent the development of resistance to the ...200818407757
synergistic effects of ovine-derived cathelicidins and other antimicrobials against escherichia coli o157:h7 and staphylococcus aureus 1056 mrsa.synergistic effects of ovine-derived cathelicidins smap29 and oabac5mini with the antimicrobials polymyxin b, lysozyme, nisin and lactoferrin were investigated against e. coli o157:h7 and s. aureus 1056 mrsa. lysozyme showed synergy against e. coli o157:h7 with smap29, polymyxin b and lactoferrin. synergy was also found between smap29 and lactoferrin against this host. against s. aureus 1056 mrsa, lysozyme showed synergy with oabac5mini, polymyxin b and nisin, while synergy was also found betwee ...200919396584
escherichia coli o157:h7 colonization in small domestic ruminants.enterohaemorrhagic escherichia coli o157:h7 was first implicated in human disease in the early 1980s, with ruminants cited as the primary reservoirs. preliminary studies indicated cattle to be the sole source of e. coli o157:h7 outbreaks in humans; however, further epidemiological studies soon demonstrated that e. coli o157:h7 was widespread in other food sources and that a number of transmission routes existed. more recently, small domestic ruminants (sheep and goats) have emerged as important ...200919207740
leaching of bioluminescent escherichia coli o157:h7 from sheep and cattle faeces during simulated rainstorm events.development of a novel inoculation technique to improve the current methods of determining the leaching of escherichia coli o157:h7 from faeces.200819146485
intermittent escherichia coli o157:h7 colonisation at the terminal rectum mucosa of conventionally-reared lambs.in cattle, the lymphoid rich regions of the rectal-anal mucosa at the terminal rectum are the preferred site for escherichia coli o157:h7 colonisation. all cattle infected by rectal swab administration demonstrate long-term e. coli o157:h7 colonisation, whereas orally challenged cattle do not demonstrate long-term e. coli o157:h7 colonisation in all animals. oral, but not rectal challenge of sheep with e. coli o157:h7 has been reported, but an exact site for colonisation in sheep is unknown. to ...200918959839
occurrence of escherichia coli o157:h7 in retail raw meat products in ethiopia.escherichia coli o157:h7 (e. coli o157:h7) is now recognized as a major cause of diarrhoea, hemorrhagic colitis and hemolytic-uremic syndrome worldwide. consumption of raw or undercooked meat of bovine origin has been the most common means of transmitting this organism.200819745509
occurrence of escherichia coli o157:h7 in faeces, skin and carcasses from sheep and goats in ethiopia.to determine the occurrence and proportion of escherichia coli o157:h7 in faeces, skin swabs and carcasses before and after washing, from sheep and goats in ethiopia.201019895421
transmission of foodborne zoonotic pathogens to riparian areas by grazing sheep.the objective of this study was to determine if sheep grazing near riparian areas on pasture in ontario are an important risk factor for the contamination of water with specific foodborne pathogens. ten ontario sheep farms were visited weekly for 12 wk during the summer of 2005. samples of feces, soil, and water were collected and analyzed for the presence of escherichia coli o157:h7, salmonella spp., campylobacter jejuni and c. coli, and yersinia enterocolitica, by bacteriological identificatio ...200919436581
oral infection with a shiga toxin-negative escherichia coli o157:h7 strain elicits humoral and cellular responses but does not protect sheep from colonisation with the homologous strain.we have previously shown that rectally inoculated sheep excrete escherichia coli o157:h7 during weeks to months without developing a clear antibody response. however, antibodies against this bacterium were observed in naturally infected sheep, which most likely became orally infected. to understand this difference, sheep were orally inoculated with the same shiga toxin-negative e. coli o157:h7 strain that was used for the rectal inoculation. a primary oral inoculation resulted in shedding of e. ...201020947271
molecular characterization of irish e. coli o157:h7 isolates of human, bovine, ovine and porcine origin.to determine the degree of relatedness between isolates of escherichia coli o157:h7 of human, bovine, ovine and porcine origin.200919486385
immunization of sheep with a combination of intiminĪ³, espa and espb decreases escherichia coli o157:h7 shedding.enterohaemorrhagic escherichia coli o157:h7 are zoonotic pathogens associated with haemorrhagic colitis (hc) and the haemolytic uremic syndrome (hus). ruminants are the main reservoir of this organism and most outbreaks of e. coli o157:h7 infections are food borne. food contamination by ruminant manure has been reported as the primary source of human infection, therefore inhibition of e. coli o157:h7 colonization and shedding in ruminants could control the risk of human exposure to this pathogen ...201021185088
reduction of escherichia coli o157:h7 excretion in sheep by oral lactoferrin administration.ruminants are an important reservoir of escherichia coli o157:h7, therefore reducing e. coli o157:h7 excretion by these animals could play a key role in reducing human infections. the present study investigates the potential of bovine lactoferrin, a natural antimicrobial-immunomodulatory protein of milk, to prevent colonization and excretion of e. coli o157:h7 in sheep. the effect of two different doses of lactoferrin (1.5g or 0.15g per 12h) was evaluated on colonization of sheep intestine and f ...201121511407
transcriptional regulators of the gad acid stress island are carried by effector protein-encoding prophages and indirectly control type iii secretion in enterohemorrhagic escherichia coli o157:h7.type iii secretion (t3s) plays a pivotal role in the colonization of ruminant hosts by enterohemorrhagic escherichia coli (ehec). the t3s system translocates effector proteins into host cells to promote bacterial attachment and persistence. the repertoire and variation in prophage regions underpins differences in the pathogenesis and epidemiology of ehec strains. in this study, we have used a collection of deletions in cryptic prophages and ehec o157 o-islands to screen for novel regulators of t ...201121492263
influence of exogenous melatonin on horizontal transfer of escherichia coli o157:h7 in experimentally infected sheep.the objective of the current research was to determine if exogenous melatonin would exert a "protective" effect on the gastrointestinal tract of sheep and prevent or reduce the horizontal transfer of escherichia coli o157:h7 from experimentally infected to noninfected or "naïve" sheep. sixteen cross-bred ewes were housed indoors and adapted to a high concentrate ration. ewes were randomly assigned to one of four rooms and treatment (three ewes/room, six ewes/treatment) and received either contro ...200919425828
prevalence of escherichia coli o157: h7 and serogroups o26, o103, o111 and o145 in sheep presented for slaughter in scotland.sheep have been proposed as a source of human verocytotoxigenic escherichia coli infection on a number of occasions but few prevalence studies have focused on identifying rates of carriage of these pathogens in this species. the purpose of this work was to establish the frequency of excretion of e. coli of serogroups o157, o26, o103, o111 and o145 in sheep presented for slaughter in scotland and to examine their carriage of known virulence determinants. the study involved microbiological isolati ...201121233295
escherichia coli o157:h7 populations in ruminants can be reduced by orange peel product feeding.foodborne pathogenic bacteria such as escherichia coli o157:h7 are threats to the safety of beef. citrus peel and dried orange pulp are by-products from citrus juice production that have natural antimicrobial effects and are often incorporated into least-cost ration formulations for beef and dairy cattle. this study was designed to determine if orange peel and pulp affected e. coli o157:h7 populations in vivo. sheep (n = 24) were fed a cracked corn grain-based diet that was supplemented with a ...201122054194
low prevalence of escherichia coli o157:h7 in horses in ohio, usa.manure from draft animals deposited in fields during vegetable and fruit production may serve as a potential source of preharvest pathogen contamination of foods. to better quantify this risk, we determined the prevalence of escherichia coli o157:h7 in horses. between june and september 2009, freshly voided fecal samples were collected from horses stabled on 242 separate premises in ohio, usa. overall, the prevalence of e. coli o157:h7 was 1 of 242 (0.4% prevalence, 95% confidence interval [ci] ...201021219723
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