California
Wildlife in General:
Preliminary
research compiling two years of data examing 866 individuals showed
that one half of one percent carried E.coli O157.
Deer:
Escherichia
coli O157:H7 in free-ranging deer in Nebraska
Abstract- In order to determine the prevalence and distribution of the
human pathogen, Escherichia coli O157:H7, in free-ranging deer, hunters
were asked to collect and submit fecal samples from deer harvested during
a regular firearm season (14-22 November 1998). Prior to the season,
47% of the hunters with permits in the southeastern Nebraska (USA) study
area indicated a willingness to participate in the study. Approximately
25% of successful hunters in the area submitted deer fecal samples.
Escherichia coli O157:H7 was cultured from four (0.25%) of 1,608 total
samples submitted. All of the fecal samples that were properly identified
(1,426) and all that were positive for E. coli O157:H7 were from white-tailed
deer (Odocoileus virginianus). We were unable to detect a statistically
significant geographic distribution pattern of E. coli O157:H7. The
presence of E. coli O157:H7 in the feces of free-ranging deer has implications
not only for hunters, consumers of venison, and others in contact with
deer or deer feces, but also for the development of strategies aimed
at reducing and/or controlling this pathogen in water sources and domestic
livestock.
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Prevalence
of Escherichia coli O157:H7 in White-tailed Deer from Louisiana
ABSTRACT- Escherichia coli O157:H7 (EC O157) is an
important zoonosis. White-tailed deer (Odocoileus virginianus)
have been implicated in transmission of this bacterium to humans and
have been suggested as reservoirs that might affect carriage in cattle
populations. Our study objectives were to estimate prevalence of EC
O157 in feces of hunter-harvested deer and to describe fecal shedding
patterns in a captive herd sampled over 1 yr. Prevalence of EC O157
in hunter-harvested deer was 0.3% (n=338). In August 2001, EC O157 was
detected in one of 55 deer (1.8%) from the captive herd. Prevalence
over the 1-yr period was 0.4% (n=226). Escherichia coli O157:H7 was
rarely isolated from hunter-harvested deer during the winter. We could
not describe a seasonal shedding pattern based on one positive sample
in the captive herd. These data do not support a prominent role of deer
as a reservoir for EC O157 for cattle or humans.
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Prevalence
of Escherichia coli O157:H7 in White-tailed Deer Sharing Rangeland
with Cattle
Abstract- To determine the prevalence of fecal shedding of
Escherichia coli O157:H7 in white-tailed deer (Odocoileus
virginianus) with access to cattle pastures. DESIGN: Survey study.
Sample Population: 212 fecal samples from free ranging white-tailed
deer. Procedure: Fresh feces were collected on multiple pastures from
2 farms in north central Kansas between September 1997 and April 1998.
Escherichia coli O157:H7 was identified by bacterial culture
and DNA-based methods. Results: Escherichia coli O157:H7 was
identified in 2.4% (5/212) of white-tailed deer fecal samples. Conclusions
and Clinical Relevance: There is considerable interest in the beef industry
in on-farm control of E coli O157:H7 to reduce the risk of
this pathogen entering the human food chain. Results of our study suggest
that the design of programs for E coli O157:H7 control in domestic
livestock on pasture will need to account for fecal shedding in free-ranging
deer. In addition, the results have implications for hunters, people
consuming venison, and deer-farming enterprises.
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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 the bacteria throughout the 26-day trial. Horizontal transmission
to an uninoculated deer was demonstrated. Although E. coli O157:H7 bacteria
were recovered from the gastrointestinal tracts of deer necropsied from
4 to 26 DPI, attaching and effacing lesions were not apparent in any
deer. Results are similar to those of inoculation studies in calves
and sheep. In field studies, E. coli O157 was not detected in 310 fresh
deer fecal samples collected from the ground. It was detected in feces,
but not in meat, from 3 of 469 free-ranging deer in 1997. In 1998, E.
coli O157 was not detected in 140 deer at the single positive site found
in 1997; however, it was recovered from 13 of 305 dairy and beef cattle
at the same location. Isolates of E. coli O157:H7 from deer and cattle
at this site differed with respect to pulsed-field gel electrophoresis
patterns and genes encoding Shiga toxins. The low overall prevalence
of E. coli O157:H7 and the identification of only one site with positive
deer suggest that wild deer are not a major reservoir of E. coli O157:H7
in the southeastern United States. However, there may be individual
locations where deer sporadically harbor the bacterium, and venison
should be handled with the same precautions recommended for beef, pork,
and poultry.
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Rodents:
Crop Notes from Monterey County's
Cooperative Extension
"Since the outbreak of E. coli O157:H7 on spinach from
California's central coast in September, 2006 there have been a number
of measures proposed and implemented to help reduce the risk of microbial
contamination in leafy green vegetables. Unfortunately, there is a lack
of science based information supporting many of these practices. The
presumed role of animals in the microbial contamination outbreaks has
caused companies to require growers to exclude animals from fields.
As a result, there have been efforts made to control rodents and other
species by using traps, baits, and fences."
Terry Salmon, Extension Vertebrate Pest Specialist,
discussed the unlikelihood of rodents as vectors of E. coli
O157:H7. "To our knowledge, voles, mice, ground squirrels, and
other rodents in coastal California agricultural fields have not been
found to harbor pathogenic E. coli...it appears unlikely that
these rodents will be found to be a common or important source of O157:H7
and other pathogenic strains."
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Feral Swine:
E.
coli O157:H7
in Feral Swine near Spinach Fields and Cattle, Central California Coast
Abstract- We investigated involvement
of feral swine in contamination of agricultural fields and surface waterways
with Escherichia coli O157:H7 after a nationwide outbreak traced to
bagged spinach from California. Isolates from feral swine, cattle, surface
water, sediment, and soil at one ranch were matched to the outbreak
strain.
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Cattle:
Prevalence
and Pathogenicity of Shiga toxin-producing Esherichia coli
in Beef Cattle and their Products
Abstract- During the past 23 years, a large number
of human illness outbreaks have been traced worldwide to consumption
of undercooked ground beef and other beef products contaminated with
Shiga toxin-producing Escherichia coli (STEC). Although several routes
exist for human infection with STEC, beef remains a main source. Thus,
beef cattle are considered reservoirs of O157 and non-O157 STEC.
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Grain
Feeding and the Dissemination of Acid-Resistant Escherichia coli
from Cattle
Abstract- The gastric stomach of humans is a barrier to food-borne
pathogens, but Escherichia coli can survive at pH 2.0 if it is grown
under mildly acidic conditions. Cattle are a natural reservoir for pathogenic
E. coli, and cattle fed mostly grain had lower colonic pH and more acid-resistant
E. coli than cattle fed only hay. On the basis of numbers and survival
after acid shock, cattle that were fed grain had 106-fold more acid-resistant
E. coli than cattle fed hay, but a brief period of hay feeding decreased
the acid-resistant count substantially.
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Scientists
Study Possible Link between Ethanol Byproduct and E. coli
Abstract- A nationwide surge in beef recalls has pointed the
finger at an unlikely culprit - the nation’s fuel ethanol industry.
Studies at two universities suggest that feeding cattle a byproduct
of ethanol production known as distillers grains may increase levels
of a deadly form of E. coli bacteria.
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Significant
Escherichia coli Attenuation by Vegetative Buffers on Annual
Grasslands
Abstract- A study was conducted to estimate the retention efficiency
of vegetative buffers for Escherichia coli deposited on grasslands in
cattle fecal deposits and subject to natural rainfall-runoff conditions.
Approximately 94.8 to 99.995% of total E. coli load applied to each
plot appears to be either retained in the fecal pat and/or attenuated
within 0.1 m downslope of the fecal pat, irrespective of the presence
of a wider vegetated buffer. Relative to a 0.1-m buffer, we found 0.3
to 3.1 log10 reduction in E. coli discharge per additional meter of
vegetative buffer across the range of residual dry vegetation matter
levels, land slope, and rainfall and runoff conditions experienced during
this project. Buffer efficiency was significantly reduced as runoff
increased. These results support the assertion that grassland buffers
are an effective method for reducing animal agricultural inputs of waterborne
E. coli into surface waters.
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Management
Reduces E. coli in Irrigated Pasture Runoff
Abstract- Microbial pollutants, some of which can cause illnesses
in humans, chronically contaminate many California water bodies. Among
numerous sources, runoff from irrigated pastures has been identified
as an important regulatory target for improving water quality. This
study examined the potential to reduce E. coli contamination
from cattle in irrigated pastures. During the 14 irrigation events examined,
we found that E. coli concentrations were lowest with a combination
of three treatments: filtering runoff through a natural wetland, reducing
runoff rates, and letting the pasture rest from grazing at least a week
prior to irrigation. Integrated pasture and tailwater management are
required to significantly reduce E. coli concentrations in
runoff.
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