Toxoplasma gondii is an obligate intracellular parasite that occasionally causes serious illness in immunocompromised individuals and unborn babies. It is estimated that one third of all humans have been exposed to T. gondii, but most instances of toxoplasmosis are mild or asymptomatic.
Growth and toxin production is best in the presence of oxygen but can grow anaerobically. It is not regarded as a good competitor with other bacteria. Infected food handlers are a significant cause of food poisonings.
This genus includes four species; S. dysenteriae, S. flexneri, S. boydii and S. sonnei, which are able to cause bacillary dysentery. They are very similar to Escherichia coli and are serologically cross reactive, but have remained separate species for clinical reasons.
Cryptosporidium parvum and Cryptosporidium hominis are intracellular protozoan parasites that may produce gastrointestinal symptoms when ingested by humans. Up until 2002, C. parvum was named C. parvum genotype 2 (cattle genotype) and C. hominis was named C. parvum genotype 1 (the human genotype). They are now recognised as different species based on genetic distinctions.
The purpose of a Risk Profile is to provide contextual and background information relevant to a food/hazard combination so that risk managers can make decisions and, if necessary, take further action. Risk Profiles include elements of a qualitative risk assessment, as well as providing information relevant to risk management. Risk profiling may result in a range of activities e.g. immediate risk management action, a decision to conduct a quantitative risk assessment, or a programme to gather more data, ranking of a particular food safety issue.
There are two pathogenic species of the Cryptosporidium parasite that infect humans; C.
parvum and C. hominis. C. parvum can also infect bovines. When excreted by the host, the
environmental form of Cryptosporidium is the oocyst, which contains four sporozoites, and is
a very resilient organism that can withstand many environmental stresses including
chlorination.
This paper is part of the New Zealand Food Safety Authority’s scientific evaluation of foodborne hazards. The focus is the bacterium Mycobacterium avium subspecies paratuberculosis (MAP), which has been reported as a possible food contaminant, particularly in dairy products.
This is one of two species of the “tubercle bacilli” (the other is M. tuberculosis) that are able to cause tuberculosis. Unlike M. tuberculosis, M. bovis infects cattle and other animals, and so the disease can be spread to humans via contaminated milk and
meat.
Enterobacter sakazakii was recently reclassified into eight distinct taxa of a new genus Cronobacter (Iversen et al., 2008). All have been linked retrospectively to clinical cases in adults and infants (FAO/WHO, 2008). To avoid confusion the organism will be referred to here as Cronobacter spp.
Arcobacter is a member of the Epsilobacteria group, which also includes Campylobacter and Helicobacter spp. It is distinguished from Campylobacter by being able to grow in the presence of oxygen (aerotolerant) and at 15ºC.
The purpose of a Risk Profile is to provide contextual and background information relevant to a food/hazard combination so that risk managers can make decisions and, if necessary, take further action. Risk Profiles include elements of a qualitative risk assessment, as well as providing information relevant to risk management. Risk profiling may result in a range of activities e.g. immediate risk management action, a decision to conduct a quantitative risk assessment, or a programme to gather more data. Risk Profiles also provide information for ranking of food safety issues.