US: Meeting new rules to beat E. coli
Posted: May 28th, 2012 - 10:27am
Source: The Beef Site
On 4 June, the USDA Food Safety and Inspection Service will begin verification testing in raw beef trimmings for seven shiga toxin producing Escherichia coli, writes Chris Harris.
These include O157, O26, O103, O111, O121, O45, and O145 and it is the first time that tests will have been instigated for non-O157 E.coli.
In all the US records nearly 1,600 cases of non-O157 E.coli each year and just six groups are responsible for more than 70 per cent of the illness.
According to Dr Fred Pohlman, sickness caused by these groups of non-O157 E.coli strains has been recognised since the turn of the century and since 2000 the cases have started to become more prevalent.
However, it is no known whether this is because there are actually more cases or because researchers have been looking for them.
While the number of cases shot up in the US between 2004 and 2008, the numbers of deaths caused has remained fairly small.
These strains of E.coli are present in both ruminant and non-ruminant animals and are found in the processing plant during slaughter.
While both pigs and cattle see a sharp drop in the prevalence of the pathogen following evisceration in the slaughter plant, sheep retain the high prevalence of E.coli.
Dr Pohlman, speaking during the American Meat Institute Expo and conference in Dallas, Texas, said that some forms of the non-O157 E.coli react in the same way to O157 to antimicrobial intervention such as lactic acid washes in reducing the amount of the pathogens in the product.
He added that ground beef is one of the major areas for concern for both E.coli and Salmonella, with between 10 and 30 per cent of ground beef being contaminated with Salmonella and 24 per cent of ground beef samples contaminated with non-O157 E.coli.
Dr Pohlman said that research into ways of controlling non-O157 E.coli had included the use of octanoic acid and electrostatic spraying of the product to give it a fine and uniform coating.
However, octanoic acid can change the colour of the meat, which reduces the appeal of the product, despite the fact that it also reduces the impact of the E.coli.
Dr Pohlman said that spraying with novel organic acids can reduce the contamination by between one and two logs and the product also retained its colour, particularly when electrostatic spraying was used as the means of application. He added that the electrostatic spraying also meant that less antimicrobial is being used.
The most prevalent forms of the non-O157 E.coli strains that have been found on meat products have been E.coli 026, 0111 and O103 and their presence is also seasonal.
Dr John Sophos, from Colorado State University showed recent research that demonstrated the current food safety intervention practices in meat processing plants in the US to counter E.coli 0157:H7 should be sufficient to counteract other non-0157 Shiga toxin producing E.coli.
He said that a study at Colorado State University looked at the effect of lactic acid, acidified sodium chlorite, peroxyacetic acid, sodium metasilicate and Bromatize on samples of beef trimmings inoculated with 3-4 log CFU/cm2 of each serotype. He said that the results showed similar effects across all the samples and were similar to the effects on O157 E.coli strains.
Under the new regulations coming in next month, FSIS will test beef manufacturing trimmings (but not ground beef, bench trim, or other components of ground beef such as cheek meat, head meat, or other components described in FSIS Directive 10,010.1) for the six non-O157 STEC serogroups (O26, O45, O103, O111, O121, and O145) in addition to E. coli O157:H7.
However, the plants are not expected to have to reassess their HACCP plans and Dr Sophos said "processors should not have to conduct separate studies to validate their processes against the sic serotypes".