Escherichia Coli O157 Research Articles

Association of Herd Management Factors with Colonization of Dairy Cattle by Shiga Toxin-Positive Escherichia coli O157

Management factors in 36 Pacific Northwest dairy herds were evaluated for their association with the prevalence of Shiga toxin-positive Escherichia coli O157 (E. coli O157) in dairy cattle. The within-herd prevalence of E. coli O157 was estimated by bacteriological culture of fecal pat samples, collected monthly for 6 months (approximately 60 per visit), from heifer cattle. During the first visit to each farm, a management questionnaire was administered that covered a broad range of animal husbandry practices. On each subsequent visit, a brief questionnaire was administered to detect changes in management practices. A significantly higher prevalence of E. coli O157 was noted in herds that fed com silage to heifers compared to herds that did not feed com silage. More tentative associations of E. coli O157 prevalence were observed for weaning method, protein level of calf starter, feeding of ionophores in heifer rations, feeding of grain screens to heifers, and feeding of animal by-products to cows.

The Big Outbreak of Hemorrhagic Colitis caused by Enterohemorrhagic Escherichia Coli O157 : H7 in Sakai City and After the Programs for Their Prevention

The Big Outbreak of Hemorrhagic Colitis caused by Enterohemorrhagic Escherichia Coli O157 : H7 in Sakai City and After the Programs for Their Prevention

Intensive (pasture) beef cattle operations: the perspective of New Zealand.

Beef production in New Zealand has characteristics typical of a temperate climate and pasture-based animal husbandry. The specific pathogens which may contaminate fresh beef and which are empirically considered to be of public health importance are similar to those in other countries with temperate climates, i.e. Salmonella, Campylobacter, Escherichia coli O157:H7, Listeria monocytogenes and Toxoplasma gondii. With the exception of T. gondii, it is likely that almost all transmission of these hazards through consumption of beef results from unseen microbial cross-contamination from gastrointestinal sources during slaughter, dressing and further processing. Gaining comprehensive information on carcass contamination levels is an essential first step in establishing food safety objectives for a particular beef production system, and in designing risk-based hazard analysis and critical control point (HACCP) plans. It is likely that the lower mean and maximum numbers of indicator micro-organisms on New Zealand carcasses (when compared with other countries) are in part due to the pre-slaughter cleanliness status of cattle reared under temperate, pasture conditions. Similarly, the failure to detect specific pathogens of gastrointestinal origin in a comprehensive baseline survey most probably reflects the limited pathway for faecal contamination during slaughter and dressing under processing conditions in New Zealand. The New Zealand example provides strong evidence for the need to design HACCP plans according to the specific national (or regional) situation. Reducing all pathways for faecal contamination of products to the maximum extent practicable will be the most important factor in achieving desired food safety objectives for fresh beef. Variable densities of microbial pathogens in gastrointestinal contents are also likely to have a significant effect on subsequent contamination levels of beef carcasses: however, effective controls for limiting the presence of most pathogens of concern in the live animal have yet to be identified.

Escherichia coli O157:H7 in livestock in Japan.

The largest ever outbreak in Japan of Escherichia coli O157 infection in humans occurred in 1996. As a result, surveys were conducted later the same year to evaluate the sources and pathogenesis of this bacillus in livestock animals at the farm and in abattoirs. One of the surveys resulted in the isolation of E. coli O157 in 0.62% of cattle on randomly selected farms. Although no confirmation has been made with regard to the source of E. coli O157 infection and its pathogenicity in livestock animals, preventive measures are being applied at both farm and processing levels.

Interruption of microbial cycles in farm animals from farm to table

The fact that only slight problems are posed by Salmonella, Campylobacter and Escherichia coli O157 in mammalian farm animals in Norway, is undoubtedly due in large degree to the agricultural set-up with small farms and small herds, allowing a good overview of the situation at any time. Other factors are the very limited import of breeding animals and food products of animal origin, microbiological control of animal feed, and favourable geographical and climatic conditions. However, the Norwegian meat industry (including abattoirs) has continuing problems with Yersinia enterocolitica O:3 in pigs and pig meat, and in some cases with Listeria monocytogenes in cold cuts and Toxoplasma gondii in sheep meat (lamb). These three agents are therefore used to illustrate appropriate measures to be taken at the herd level on the farm, in abattoirs and in the meat processing industry.

Cattle as a possible source of verocytotoxin-producingEscherichia coliO157 infections in man

In May-June 1992 cases of infection with verocytotoxin-producing (VT+) Escherichia coli O157 in South Yorkshire could have been associated with prior consumption of beef from a local abattoir. During investigation of the abattoir, bovine rectal swabs and samples of meat and surface swabs from beef carcasses were examined for E. coli O157, isolates of which were tested for toxigenicity, plasmid content and phage type. E. coli O157 was isolated from 84 (4%) of 2103 bovine rectal swabs; of these 84, 78 (93%) were VT+, the most common phage types being 2 and 8, the types implicated in the cluster of human cases. Positive cattle were from diverse sources within England. E. coli O157 was isolated from 7 (30%) of 23 carcasses of rectal swab-positive cattle and from 2 (8%) of 25 carcasses of rectal swab-negative cattle. The study has shown that cattle may be a reservoir of VT+ E. coli O157, and that contamination of carcasses during slaughter and processing may be how beef and beef products become contaminated and thereby transmit the organism to man.

Update: Multistate Outbreak of Escherichia coli O157:H7 Infections from Hamburgers— Western United States, 1992-1993

From November 15, 1992, through February 28, 1993, more than 500 laboratory-confirmed infections with E. coli O157:H7 and four associated deaths occurred in four states--Washington, Idaho, California, and Nevada. This report summarizes the findings from an ongoing investigation that identified a multistate outbreak resulting from consumption of hamburgers from one restaurant chain.

A waterborne outbreak in Missouri of Escherichia coli O157:H7 associated with bloody diarrhea and death.

To describe and determine the source of a large outbreak of Escherichia coli O157:H7 (ECO157) infections in Missouri. A case-control study and a household survey. A small city in a rural Missouri township that had an unchlorinated water supply. Case patients were residents of or visitors to Burdine Township with bloody diarrhea or diarrhea and abdominal cramps occurring between 15 December 1989 and 20 January 1990. Escherichia coli O157 was isolated from 21 stool specimens. All isolates were resistant to sulfisoxazole, tetracycline, and streptomycin; produced Shiga-like toxins I and II; and had one 60-megadalton plasmid. Among the 243 case patients, 86 had bloody stools, 32 were hospitalized, 4 died, and 2 had the hemolytic uremic syndrome. In the case-control study, no food was associated with illness, but ill persons had drunk more municipal water than had controls (P = 0.04). The survey showed that, during the peak of the outbreak, bloody diarrhea was 18.2 times more likely to occur in persons living inside the city and using municipal water than in persons living outside the city and using private well water (P = 0.001). Shortly before the peak of the outbreak, 45 water meters were replaced, and two water mains ruptured. The number of new cases declined rapidly after residents were ordered to boil water and after chlorination of the water supply. This was the largest outbreak of ECO157 infections, the first due to a multiply resistant organism, and the first shown to be transmitted by water. System-wide chlorination as well as hyperchlorination during repairs might have prevented this outbreak. Both bloody and nonbloody diarrhea may be common manifestations of this infection, which is probably underdiagnosed because of the failure of routine stool cultures to identify the organism. Cities with deteriorating water systems using untreated water risk widespread illness from contaminated drinking water.

Oncology nursing

Two hundred food samples of animal origin confiscated from passengers arriving on flights from non-European countries at the International Airport of Bilbao (Spain) were tested for the presence of four main bacterial foodborne pathogens (Campylobacter spp., Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp.) during 2012 and 2013. Overall, 20 samples were positive for L. monocytogenes (10%) and 11 for Salmonella spp. (5.5%), whereas Campylobacter spp. and E. coli O157:H7 were not detected in any sample. The positive isolates were widely clustered: 14 and 7 different pulsotypes for L. monocytogenes and Salmonella spp. isolates, respectively. Nine sequence types (ST) were detected for L. monocytogenes: ST2 (45%), ST9 (15% isolates), ST8 and ST87 (10%), and ST308, ST37, ST155 and ST378 (5%). The Salmonella spp. isolates belonged to seven serovars: monophasic serovar 4,12:d:− (3; 27.3%), Rauform (2; 18.2%), Anatum (2; 18.2%), Oranienburg, Enteritidis, Newport and Typhimurium (1; 9.1% each). Antibiotic resistance among L. monocytogenes isolates was high, especially for clindamycin and daptomycin (more than 95% of the isolates). These results indicate that food samples imported by travelers in their personal luggage may harbor the most prevalent L. monocytogenes genotypes and Salmonella spp. serovars responsible for foodborne outbreaks worldwide. Consequently, international travel can play an important role in the prevalence and dissemination of successful clones of foodborne pathogenic bacteria, and continuous monitoring of international movements is of importance to better understand clonal evolution and emergence and dissemination of successful lineages.

Nonpoint Pollution From Animal Sources and Shellfish Sanitation

Many of the microorganisms pathogenic to both animals and man are transmitted via the fecal-oral route. Most of these pathogens could conceivably be transmitted through a shellfish vector. Bacteria potentially transmitted from animal to man via shellfish include most of the salmonellae, Yersinia enterocolitica, Yersinia pseudotuberculosis, Escherichia coli O157:H7, Campylobacter jejuni, and Listeria monocytogenes. The protozoa most likely to be transmitted this way are Giardia lamblia and Cryptosporidium spp. Because the enteric viruses are highly species-specific, they are not likely to be transmitted from animals to humans. There are environmental data showing that bacterial pathogens shed by both domestic and wild animals have been isolated from shellfish. However, there is little epidemiological evidence that illness outbreaks have been caused by shellfish harvested from waters polluted by animals. Unfortunately, epidemiological observations are of limited value because most illnesses are probably not recorded. In addition, more than half of the recorded outbreaks are of unknown etiology, and more than half of the shellfish implicated in illness outbreaks cannot be traced to their points of origin. More lenient bacteriological standards should not be established for waters affected only by animal pollution until health effects studies have been performed, and an indicator that differentiates between human and nonhuman fecal pollution is available. Most of the pollution that originates from domestic animals could be eliminated by simple and inexpensive measures.