Grass-Fed Cattle and E. coli O157:H7
Researchers have busted the food safety myth that grass-fed beef has less risk of E. coli O157:h7 than grain-fed beef. The study, to be published in Foodborne Pathogens and Disease, tested bacterial contamination rates in 50 beef products labled as “grass-fed” and 50 conventionally raised beef products. The percentages of Escherichia coli positive samples did not differ between the two groups (44% vs. 44%).
The researchers conclusion:
Taken together, these data indicate that there are no clear food safety advantages to grass-fed beef products over conventional beef products.
Source: Jiayi Zhang, Samantha K. Wall, Li Xu, Paul D. Ebner, “Contamination Rates and Antimicrobial Resistance in Bacteria Isolated from “Grass-Fed” Labeled Beef Products,” Foodborne Pathogens and Disease. -Not available-, ahead of print. doi:10.1089/fpd.2010.0562.
Cranberry Juice and the Mechanical Forces Involved in the Attachment of E. coli O157:H7
Researchers at Worcester Polytechnic Institute (WPI) in Massachusetts may have discovered why cranberry juice fights off E. coli O157:H7 infections. In a paper published this month by Molecular Nutrition and Food Research, “Direct adhesion force measurements between E. coli and human uroepithelial cells in cranberry juice cocktail“, Professor Terri Camesano and his team present the first specific measurements of the mechanical forces involved in the attachment of the virulent E. coli to human urinary tract cells.
The study also documents how the force of attachment is reduced in the presence of cranberry juice cocktail. “This is not a clinical study—it’s a mechanical study that shows us the direct forces that can lead to infection,” Camesano said.
E. coli O157:H7 is covered with small hair-like projections known as fimbriae which act like hooks and latch onto cells that line the urinary tract. When enough of the virulent E. coli adhere to cells in this way, they cause an infection. Previous work by Camesano has shown that exposure to cranberry juice causes the fimbriae on E. coli to curl up, reducing their ability to attach to urinary tract cells.
“We know, on average, how many fimbriae are on each E. coli cell. And the total force we measured correlates with that number. So the data lead us to believe that the fimbriae each bind to a specific receptor on the uroepithelial cells,” Camesano said.
The data showed that the attachment force of the virulent E. coli weakened as the amount of cranberry juice cocktail increased. The study also showed that a strain of E. coli without fimbriae did not bind well to the human urinary tract cells, regardless of the concentration of cranberry juice cocktail, providing further evidence that fimbriae are essential for infection.
Furthermore, Camesano’s team found that in the absence of cranberry juice, the strength of the virulent E. coli’s bond to the human cells was so strong that it could not be broken by the typical force of urine flowing through a person’s urinary tract. However, as the cranberry juice concentration increased, the bond weakened to the point where the E.coli could be stripped away by the force of flowing urine. “The shear force created by flowing urine is a defense mechanism against urinary tract infection,” Camesano said.
Federal Government Unveils Product Recalls App
Product recalls–the feds have an app for that. The Products Recall app is available at the app store on the USA.gov site. It is only available for the Android smartphone now, but the apps for Blackberry and iPhone are soon to follow.
The Products Recall app pulls information from several federal agencies, including the U.S. Department of Agriculture’s Food Safety Inspection Service (FSIS) and the Department of Health and Human Services’ Food and Drug Administration (FDA), the agencies that report food recalls.
The app allows consumers to view the most recent recall press releases and any pictures associated with those products. Consumers can get information of specific interest to them using a feature on the app that searches recalled products by product name or category.
The app’s “report incident” feature allows consumers to connect directly with their government to report concerns of unsafe products. A “tips” option will feature rotating educational messages for consumers about a variety of products, such as highlighting safe food handling tips as popular cooking holidays approach.
“Our goal is to quickly inform the public and media when food products are recalled,” said USDA Deputy Under Secretary for Food Safety Jerold Mande. “This app puts the information directly in the hands of consumers, giving them the power to take action.”
In addition to foods regulated by FSIS and FDA, the Products Recall app also includes recall information for drugs, cribs, strollers, child safety seats, tires, and other consumer products.
Minnesota Department of Agriculture Focusing on Raw Milk after E. coli Outbreak
Earlier this month, Minnesota health officials linked an E. coli O157:H7 outbreak that sickened 8 people to raw milk products from the Hartmann Dairy Farm in Gibbon, Minnesota.
During their investigation of the Hartmann farm, health officials found 28 environmental and animal samples from the Hartmann farm that tested positive for E. coli O157:H7. Twenty-six samples had the same DNA fingerprint as the outbreak strain of E. coli O157:H7. The positive samples included environmental samples from the dairy barn where the cows are milked, according to the Minnesota Department of Agriculture.
The Minnesota Department of Agriculture now has a link to the following raw milk information on the home page of its website:
Raw milk, or milk straight from the cow, sheep or goat without any further pasteurization or processing, can contain harmful bacteria that may cause people who consume the milk to become sick. These bacteria can come from many sources on the farm including:
- The animals themselves
- Milking equipment contaminated with manure
- Water
- Soil
- Anywhere that fecal contamination can be found
Some of these bacteria include:
- Campylobacter
- E. coli O157:H7
- Salmonella
- Listeria
Because of the potential risks associated with consuming raw milk, Minnesota law restricts the sale of this type of milk for human consumption. The law does provide an alternative for people who want to consume raw milk. On an occasional basis, consumers may go directly to farms to secure the raw milk directly from the farmer. This exemption applies to cow, goat and sheep farms (or any other species producing milk for human consumption) equally.
The Minnesota Department of Agriculture has stepped up its enforcement of a Minnesota law that prohibits the sale of raw milk unless a consumer, using his or her own bottle, buys the milk at the farm where the milk is produced. Minnesota Statutes 32.393 Limitation on Sale of Milk reads as follows:
“No milk, fluid milk products…shall be advertised, offered or exposed for sale…for the purpose of human consumption in fluid form in this state unless the same has been pasteurized and cooled… this section will not apply to milk… occasionally secured or purchased for personal use by any consumer at the farm where the milk is produced.
E. coli Found in Reusable Grocery Bags
Research out of the University of Arizona in Tucson and Loma Linda University in Loma Linda, California found Escherichia coli (E. coli) in 12 % of reusable grocery bags used for the study. Researchers collected shopping bags from consumers entering grocery stores in San Francisco, Los Angeles and Tucson. Owners of the bags were interviewed on bag usage, storage and cleaning.
Only 3% of the reusable grocery bag owners bothered to wash their bags, which was determined by the researchers to reduce the bacteria in bags by 99.9%. Also, people used the same bags to carry meat and produce, creating a situation ripe for cross contamination.
E. coli Ground Beef Recall by South Gate Meat Co.
An E. coli ground beef recall has been issued by South Gate Meat Company after E. coli O157:H7 contamination was discovered in the meat, according to the U.S. Department of Agriculture’s (USDA’s) Food Safety and Inspection Service (FSIS).
The South Gate, California company ground beef recall includes about 35,000 pounds of various ground beef products that have the establishment number “EST. 6217″ inside the USDA mark of inspection. They were produced from June 7, 2010 through June 21, 2010 and distributed to Los Angeles restaurants and other restaurants in the Orange County area. The recalled beef includes the following products:
- 20-, 30- and 40-pound bulk packages of “SOUTH GATE MEAT CO. GROUND BEEF.”
- 30-, 40-, and 50-pound bulk packages of “SOUTH GATE MEAT CO. COARSE GROUND BEEF.”
- 10- and 20-pound packages of “SOUTH GATE MEAT CO. GROUND BEEF PATTIES.
Inspection of samples through microbiological testing by the FSIS originally revealed the E. coli beef contamination.
