Research Looks at How E. coli Attaches to Cattle Guts
Research out of the U.S. Department of Agriculture (USDA) has discovered key gene and chemical interactions that allow Escherichia coli (E. coli) O157:H7 bacteria to colonize the gut of cattle, a problem because cattle manure contaminated with E. coli can contaminated thousands of pounds of ground beef or a crop of leafy greens (cross contamination).
The researchers, including USDA Agricultural Research Service (ARS) animal scientist Thomas S. Edrington, reported how the E. coli sense a key chemical that plays a critical role in allowing the bacteria to colonize inside the cattle’s gastrointestinal (GI) tract.
To proliferate, E. coli express genes differently based on their environment, such as outside the cattle host, inside the cattle rumen, or even at the end of the cattle GI tract. Having a better understanding of when, why and how these bacteria colonize could lead to practical applications in the future, according to Edrington.
The researchers showed that “quorum sensing” chemicals called acyl-homoserine lactones (AHLs), which are produced by other bacteria, are present within the bovine rumen but absent in other areas of the cattle GI tract. AHLs are important because E. coli harbor a regulator, called SdiA, which senses these AHLs and then prompts the E. coli to attach and colonize.
The research suggests that limiting production of the SdiA chemical, or blocking bacterial reception of the AHLs, may eventually lead to new strategies for keeping E. coli from attaching inside the animal.
The study, published in the Proceedings of the National Academy of Sciences, was conducted at the University of Idaho, Moscow, Idaho, campus. It involved researchers from several universities and was headed by Vanessa Sperandio, who is with the University of Texas Southwestern Medical Center, in Dallas.
BJ’s Wholesale Club Ground Beef Recall for E. coli 026
The only retailer identified so far as a distributor of recalled Cargill ground beef that may be contaminated with E. coli 026 is BJ’s Wholesale Club stores in eight northeastern and eastern states.
USDA has associated the Cargill E. coli ground beef recall with three confirmed illnesses caused by the identical strain of E. coli 026. There are two cases in Maine and one in New York. The agency’s initial Cargill ground beef recall distribution list includes 26 BJ’s Wholesale Club stores in Maine, New York, Connecticut, Maryland, Virginia, New Hampshire, New Jersey and New York.
An active E. coli ground beef investigation is continuing. The tainted Cargill ground beef was produced June 11 for use or freezing by July 1. People started to get sick June 24. Public health officials at the state and federal level are concerned that more outbreak cases could surface if consumers unknowingly pull recalled ground beef from their home freezers for meal preparation.
Cargill’s recalled ground beef was sold to BJ’s Wholesale Club in 42-pound cases. Fourteen-pound “chubs” inside the cases were for repackaging into trays of ground beef for sale in BJ’s Wholesale Club meat cases. The products subject to recall bear the establishment number “EST. 9400″ inside the USDA mark of inspection. The Class I recall covers 8,500 pounds of Cargill ground beef.
According to the Centers for Disease Control and Prevention, E. coli O157:H7 causes 73,000 illnesses and 50 deaths every year in the United States. Another six E. coli strains – including O26 — are less pervasive but just as capable of causing severe illness, including hemolytic uremic syndrome (HUS).
Due to a gaping shortfall in federal law, only E. coli 0157:H7 is banned from ground beef as an adulterant. The prohibition hasn’t ended E. coli 0157:H7 contamination, but it has forced meatpackers to constantly test for it and it also calls for routine government testing of the products.
Maine E. coli Ground Beef Investigation
A Maine E. coli ground beef investigation traced E. coli 026 illnesses in Maine and New York to Cargill ground beef recalled early today in conjunction with USDA’s Food Safety and Inspection Service (FSIS).
An FSIS ground beef recall announcement said Cargill Meat Solutions Corp of Pennsylvania is recalling 8.500 pounds of ground beef that may be contaminated with E. coli 026, a potentially lethal human pathogen. The meat was produced June 11 and sold in 14-pound “chubs” to retailers who repackaged it for meat case display. The affected store brands haven’t been announced yet. The tainted ground beef was initially shipped to distribution centers in Connecticut and Maryland for further sale.
Two people from Maine and one from New York have been infected by the same identical strain of E. coli 026 and health investigators in the two states are continuing their efforts to learn the extent of this outbreak. Cargill is a large multi-national corporation that has been involved in E. coli ground beef recalls and outbreaks in the past. FSIS has found a convincing association between the Maine and New York E. coli cases and ground beef from Cargill.
Eating ground beef is a well-established mode of shiga toxin-producing E. coli (STEC). The most prevalent type of STEC is O157:H7, but E. coli 026 also produces shiga toxin that attacks a person’s red blood cells. In 5 to 15 percent of STEC infections, patients develop hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpura (TTP), a related condition.
HUS is the leading cause of kidney failure, worldwide, in children. It also can damage other parts of a person’s body, including the heart, brain and central nervous system. HUS in children is deadly in about 5 percent of cases.
Here is the Cargill E. coli ground beef recall announcement:
The products subject to recall bear the establishment number “EST. 9400″ inside the USDA mark of inspection. The recall includes 42-pound cases of “GROUND BEEF FINE 90/10,” containing three (3) – approximately 14 pound chubs each. These products have a “use/freeze by” date of “07/01/10,” and an identifying product code of “W69032.”
Child E. coli HUS case Prompts Look at County Fair
Three children aged 5 through 15 were all sickened by shiga toxin-producing E. coli after attending the Northwestern Michigan County Fair. If the cause of the illnesses came from the fair, officials say the most likely source of transmission was contact with animals that carried the bacteria.
The cluster of E. coli is being investigated by the Michigan state health authority and the Grand Traverse County Health Department. 9 & 10 News reported tonight that one of the children remains hospitalized. Children under 5 are in the age group most susceptible to developing a complication of E. coli infection known as hemolytic uremic syndrome (HUS). HUS can keep children hospitalized for lengthy periods with kidney failure and many other impairments caused by the toxin.
Michigan health officials are taking the opportunity of the outbreak to remind families to practice strict hand hygiene at county fairs and other animal exhibits. Cattle and other animals shed E. coli from their feces and it can survive on the hides of cattle and other animals.
Canadian E. coli Outbreak Associated With Festival
At least 26 people have fallen sick from a suspected E. coli outbreak in Winnipeg, Manitoba. Canadian health officials have associated the majority of cases with food eaten at the Russsian pavilion of the annual Folklorama multicultural festivals, CBC News-Radio Canada reports. The Winnipeg Regional Health Authority issued a warning last week after 15 suspected cases had surfaced since the beginning of August.
Of those who have become sick, 14 have been confirmed to have E. coli, including two children who are still recovering in hospital, according to the CBC report. Folklorama ended August 14, but there is a risk of secondary infection. Once someone has eaten contaminated food, the infection can be passed person to person, by hand-to-mouth contact.
