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.
Researchers Outsmart E. coli with Cockroach Brains
Certain strains of E. coli have become multi-drug resistant “super bugs” and a threat to human health. But these super-strength E. coli have met their match in the indestructible cockroach.
Scientists at the University of Nottingham School of Veterinary Medicine and Science have discovered that certain tissues in cockroach brains are able to kill more than 90 per cent of pathogenic Escherichia coli without harming human cells. Other bacteria, such as multi-drug resistant MRSA are also annihilated by cockroach brains.
The research has identified up to nine different molecules in the insect tissues that were toxic to bacteria.
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.”
E. coli Water Contamination in Texas Restaurant Under Investigation
E. coli contamination in water caused Fralo’s Pizza of Leon Springs, Texas to be temporarily shut down, although the restaurant reopened this week, according to local news sources. Dozens of diners and restaurant employees reportedly became sick after eating at the restaurant, and these contamination problems began at the same time a sewage leak occurred across the street from the restaurant.
Health officials have not attributed the restaurant’s water contamination to the spill, which involves up to 400,000 gallons of sewage that leaked into the ground. However, tests of the restaurant’s water are now showing no contamination as health officials continue to investigate the source of the problem.
“It is very hard to determine because there are so many factors that can impact water quality especially from a well, such as septic tanks,” said Sarah Gateswood of San Antonio Water System. “We know the area has a lot of septic tanks. The most important thing is for people to rest assured that the tests we are taking are coming back clean.”
The restaurant owner said he will hire a firm to regularly test the well. Right now, as an extra safety precaution, Fralo’s Pizza is still testing the water every day.
Sources:
http://www.ksat.com/news/24735142/detail.html
http://www.saws.org/latest_news/NewsDrill.cfm?news_id=702
Federal Agencies Join Forces to Promote Produce Safety
Fresh produce, particularly lettuce, has become an increasingly common source of E. coli infection in the United States. The Food and Drug Administration, which has some regulatory authority over the produce industry, is promulgating a new rule for the safe production, harvesting and packing of fresh produce. FDA announced it is working more closely than ever with the U.S. Department of Agriculture and its agencies, the Environmental Protection Agency, state departments of agriculture, advocacy groups, and growers to ensure the effectiveness of the new rule.
Over the past several months, FDA and USDA technical experts, scientists, and other staff have participated in listening sessions and meetings in 13 states and toured farms to hear from people who have the “on-the-ground” knowledge that FDA states must be reflected in the proposed rule. In addition, more than 700 comments were received from all parts of the country and around the world from growers; environmental groups; state and local government agencies; retail food chains; academia; consumers, and others.
The comments have been sorted and routed to specific areas that these groups have been focusing on, and will be carefully considered and evaluated for inclusion. In addition, FDA will consider testimony and comments received by the U.S. Department of Agriculture (USDA) in response to the proposed National Leafy Greens Marketing Agreement, as well as comments FDA received in response to its draft guidance on leafy greens, tomatoes and melons, issued in 2009.
FDA anticipates publishing a proposed fresh produce rule in 2011. The proposed rule will have a comment period, whereby stakeholders can provide comments and feedback to agency before the final rule is issued.
Three Children Who Attended Grand Traverse County Fair Contract E. coli Infections
Grand Traverse County health officials are investigating a cluster of E. coli O157:H7 infections in three children who attended the Grand Traverse County Fair. The connection between the three children stops there, however. They did not eat food from the same vendors or tend the same animals.
The first two cases of E. coli O157 was reported to the health department last Friday. The third case was reported on Monday. Health officials have sent E. coli isolates taken from the three children to a lab for genetic testing to determine if they have the same genetic fingerprint. This would be evidence that all of the children were sickened by the same E. coli source.
Health officials have taken environmental samples throughout the fairgrounds, including water samples, to try to find the source of the outbreak. Extremely small amounts of E. coli bacteria can result in infection and serious illness, including hemolytic uremic syndrome (HUS), which can cause kidney failure, brain damage, pancreatitis, blindness and death. The water was tested before the fair began, and E. coli bacterium were not found, but this does not mean it was free of the bacteria when the children visited.
The Grand Traverse County Health Department learned about two cases on Friday and a third on Monday, but officials haven’t been able to connect them except through the annual fair in Blair Township.
The children, who are not related, range from 5 to 15 years old. They did not work with the same livestock and did not eat from the same vendors, said Fred Keeslar, department health officer.
“We were hoping to find some common links, but didn’t,” he said.
Health officials have no positive proof the outbreak originated at the fair, but it remains the likeliest connection.
“There are lots of animals coming together and people touching animals that are kicking up dust,” Keeslar said.
Humans may be exposed to E. coli through contact with animal fecal matter. Symptoms include vomiting, stomach cramps and diarrhea, sometimes bloody diarrhea.
“It can lead to, in the worst case, renal failure and death,” Keeslar said.
Further testing is under way to pinpoint the specific type of E. coli. The best preventative measure is frequent hand-washing when in contact with barnyard animals.
Fair President Dana Cederquist could not be reached for comment.
Nancy Schroeder, secretary for the Northwest Michigan 4-H Livestock Council, said sanitation and hand-washing is part of annual plans at the fair.
“We have five hand-washing stations with running water and antibacterial soap. We also have hand sanitizer at the petting zoo,” she said.
Schroeder said fair-goers are encouraged to wash their hands before and after contacting animals, with warnings on banners hung at the fairgrounds, as well as signs posted at all barn entrances and in the restrooms.
“We try to make the public aware and we try to provide them with what they need on the grounds,” she said.
Darrel Robinson, president of the livestock council, said the bacteria associated with the ill children is a known risk with livestock and the reason warnings are prominently displayed across the fairgrounds. Additionally, fair planners participate in annual biohazard training in preparation for the fair, he said.
At least two of the stricken children are not involved with 4-H, though the third could have handled livestock, Keeslar said.
Shiga toxin-producing E. coli, also called STEC infections, can affect people of any age, though the very young and elderly are the most susceptible, according to the Centers for Disease Control and Prevention.
STEC live in the guts of cud-chewing hoofed animals, including cattle, goats and sheep, though the primary source for human illnesses is cattle. Other kinds of animals, including pigs and birds, sometimes pick up STEC from the environment and may spread it, according to the CDC.
Keeslar said all three infected Grand Traverse area children are expected to fully recover, though the 5-year-old remained hospitalized on Tuesday. The other two children were treated and released.
Officials tested water sources at the fairgrounds before the week-long event and on Tuesday took new samples to verify whether water became contaminated. Results are expected in several days, Keeslar said.
Health officials notified area doctors to watch for STEC symptoms in their patients because those who came into contact with the bacteria but didn’t become ill could still spread the infection to others, particularly those with weakened immune systems.
