Published Date: 2008-10-21 22:00:34
Subject: PRO/AH/EDR> E. coli O157 - USA (09): (WA), susp.
Archive Number: 20081021.3336
E. COLI O157 - USA (09): (WASHINGTON), SUSPECTED
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Tue 21 Oct 2008
Source: The Seattle (WA) Times [edited]
The Snohomish Health District is investigating 14 unconfirmed cases
of _E. coli_ O157:H7 infection. Spokeswoman Suzanne Pate said the
district's nurses noted 2 cases last week [week of 13 Oct 2008] and
on Friday [17 Oct 2008] asked Snohomish County physicians to do
further testing if any patients came in with bloody diarrhea for at
least 2 days, a symptom of this strain of _E. coli_.
By noon Monday [20 Oct 2008], medical professionals in the county had
reported a total of 14 cases, none of which have yet been confirmed
by additional testing, which can take several days.
Snohomish County has between 16 and 20 reported cases of this
infection in a year, "so this is a significant number," Pate said.
The source of the contamination isn't known, she said.
On Monday [20 Oct 2008], the American Department of Agriculture
[USDA] said cattle fed an ethanol byproduct called distiller's grain,
a cheap and common feed, have a higher concentration of acid in their
digestive tracts and are more likely to have _E. coli_ O157:H7 than
corn-fed cattle. The Department of Agriculture didn't tell farmers to
refrain from feeding distiller's grain to cattle.
"Public Health in Snohomish County is working to solve this disease
puzzle," said director Dr Gary Goldbaum. "No single source is jumping
out at us from the preliminary investigation. However, we learn more
with each interview and each lab test."
[Byline: Nancy Bartley]
Michael P. Owen
USA FDA Pacific Regional Lab Northwest
[The confirmation of E. coli O157:H7 is forthcoming but appears likely.
The following is an abstract from a study reported earlier this year
(2008) from Kansas State University (Jacob ME, Fox JT, Drouillard JS,
Renter DG, Nagaraja TG, Effects of dried distillers' grain on fecal
prevalence and growth of _Escherichia coli_ O157 in batch culture
fermentations from cattle. Appl Environ Microbiol. 2008; 74: 38-43)
reporting that the use of distiller's grains as a bovine food
contributes to increasing the amount of entero-hemorrhagic _E. coli_
"Distillers' grains (DG), a by-product of ethanol production, are fed
to cattle. Associations between _Escherichia coli_ O157 prevalence
and feeding of DG were investigated in feedlot cattle (n = 379) given
1 of 3 diets: steam-flaked corn (SFC) and 15 percent corn silage with
0 or 25 percent dried distillers' grains (DDG) or SFC with 5 percent
corn silage and 25 percent DDG. 10 fecal samples were collected from
each pen weekly for 12 weeks to isolate _E. coli_ O157.
"Cattle fed 25 percent DDG with 5 or 15 percent silage had a higher (P
= 0.01) prevalence of _E. coli_ O157 than cattle fed a diet without
DDG. Batch culture ruminal or fecal microbial fermentations were
conducted to evaluate the effect of DDG on _E. coli_ O157 growth. The
1st study utilized microbial inocula from steers fed SFC or
dry-rolled corn with 0 or 25 percent DDG and included their diet as
the substrate. Ruminal microbial fermentations from steers fed DDG
had higher _E. coli_ O157 contents than ruminal microbial
fermentations from steers fed no DDG (P less than 0.05) when no
substrate was included. Fecal fermentations showed no DDG effect on
_E. coli_ O157 growth. In the second study with DDG as a substrate,
ruminal fermentations with 0.5 g DDG had higher (P less than 0.01)
_E. coli_ O157 concentrations at 24 hr than ruminal fermentations
with 0, 1, or 2 g DDG. In fecal fermentations, 2 g DDG resulted in a
higher concentration (P less than 0.05) at 24 hr than 0, 0.5, or 1 g
DDG. The results indicate that there is a positive association
between DDG and _E. coli_ O157 in cattle, and the findings should
have important ramifications for food safety."
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