USDA moves to curtail salmonella incidences

New pathogen reduction performance standards have been developed by the US Department of Agriculture (USDA) for the control of Salmonella and Campylobacter bacteria in chilled carcasses at young chicken and turkey slaughter establishments that are eligible for agency verification sampling.

The USDA’s Food Safety and Inspection Service (FSIS) said that these new standards respond to certain key recommendations of the President's Food Safety Working Group to reduce the prevalence of these disease-causing bacteria in poultry.

The agency said its Salmonella verification programme aims to have 90 per cent of poultry establishments meeting the new standards by the end of 2010.

Prior to this, FSIS had standards for Salmonella but not for Campylobacter. The agency claims the new Campylobacter standards will also limit the number of positive samples that are acceptable in a defined set.

FSIS said that the new standards are based on the analysis of data from recent FSIS baseline sample collection programs for young chickens and turkeys. It has yet to publish specific details concerning the new standards.

Chicken safety

A recent consumer survey found salmonella and/or campylobacter in about two-thirds of chickens tested in the US.

Consumer Reports assessed 382 chickens from 100 stores in its regular survey of chicken safety and found campylobacter in 62 per cent, salmonella in 14 per cent, and both bacteria in 14 per cent.

A total of 34 per cent of birds were clean of both pathogens, which is double the figure found in 2007, but Consumer Reports did not find this cause for celebration.

The consumer watchdog called it a “modest improvement” and said the number of clean birds was still far smaller than the 51 per cent identified in 2003. “The numbers are still far too high, especially for campylobacter,” said Consumer Reports.

To support the case it quoted figures from the Centers for Disease Control and Prevention, indicating that salmonella and campylobacter from food sources infect 3.4m Americans a year, resulting in 25,500 hospital cases, and 500 deaths.

Air chilling

Among the 382 chickens tested in the latest report, air chilled birds were the cleanest, with 40 per cent carrying pathogens. Air chilling is a poultry processing technique, whereby birds are hung by shackles and moved through coolers with rapidly moving air, rather than being dunked in cold chlorinated water.

For the first time, Consumer Reports found one major brand, Perdue’s, which fared significantly better than others. It said 56 per cent of the chickens were free of salmonella and campylobacter. This compared with 20 per cent in the two poorest performing brands, Tyson and Foster Farms.

Responding to the survey, the National Chicken Council, which represents chicken producers and processors, insisted that chicken is safe. It said raw chicken may have some microorganisms present, but that these are destroyed by the heat of normal cooking.

Stressed birds

Meanwhile research by the University of Bristol in the UK claims the release of a hormone at times of stress could be crucial to understanding why some food poisoning bacteria become more invasive in animals after transportation.

The study, led by Professor Tom Humphrey, examined the behaviour of campylobacter in chickens. They found the animals released higher levels of hormone noradrenalin when under stress which actually helps campylobacter and salmonella grow and spread more quickly.

A further finding from the study said campylobacter can interact with other organisms in the gut of food animals, making it even more invasive. The results of the research provide vital information to enable the control of infection in the production environment, making chicken safer and decreasing cases of food poisoning, said the researchers.