In pregnant women, Listeria
infections can lead to miscarriages, stillbirths, premature delivery, or life-threatening infection of a newborn.
The Food Standards Agency said it was still trying to identify where the listeria
may have come from in the supply chain.
In June, public health officials said five seriously-ill patients had died and nine more infected, after eating food which contained the deadly bacteria listeria
Researchers working with Urs Spitz and Doron Shabat at the University of Tel Aviv, Nemis Technologies AG (Zurich, Switzerland), Zurich University of Applied Sciences, and Biosynth AG (Staad, Switzerland) have now introduced a new and efficient method for the ultrasensitive and significantly faster detection of Salmonella and Listeria
. The method is based on chemiluminescence--the emission of light resulting from a chemical process.
The trigger is tailored to the bacteria to be detected: it is recognised by a specific enzyme produced by the pathogen a special esterase in the case of salmonella and a special phospholipase C for listeria
that splits it from the luminescent part.
A spokesman for the Good Food Chain said: "We welcome the Food Standards Agency's announcement that the Good Food Chain is no longer part of the ongoing investigation into the recent listeria
outbreak." "While this means we can now resume production, we have not yet taken any decision about whether it is viable to do so.
He said that before the listeria
outbreak was uncovered, an inquest had already been held into Mrs Sowah's death and he had concluded no hearing was needed for Ms Heap's death.
But the listeria
strain which affected her was found in another patient at Manchester Royal Infirmary who died 10 days later.
outbreak: Two more hospitals where patients died named
The chain had been supplied with meat produced by North Country Cooked Meats, which subsequently produced a positive test result for the outbreak strain of listeria
infection is rare and usually causes a mild illness in healthy people.
Cases of listeria
infection were found in six seriously-ill hospital patients.