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Microbial Pathogen Data Sheets

The following microbiological data sheets have been prepared for the New Zealand Food Safety Authority by the Institute of Environmental Science and Research Limited (ESR).

Food industry associations, food businesses and food safety consultants can use this information to help understand the microorganisms they need to control in their, or their client's, food processes. The data sheets provide essential information, although are not exclusive, for use when developing HACCP-based programmes.

The information will also prove useful to regulators when developing requirements for risk-based food control programmes, and for approved auditors when assessing the safety of food processes.

Arcobacter spp
Arcobacter belongs to the same family of organisms as Campylobacter.  While a definitive link between Arcobacter and human disease has not yet been established, there is increasing concern that these organisms could be responsible for some of the unconfirmed cases of gastroenteritis.

Bacillus cereus
Bacillus cereus can cause two forms of disease, emetic and diarrhoeal, due to the production of toxins. The food vehicles involved are usually cooked rice or protein-rich dishes. Disease is usually mild and short-lived, but is a quite common consequence of temperature abuse during food storage.

Campylobacter
Campylobacter is the most frequent notified cause of enteric disease in New Zealand and many other countries around the world. Infection by the organism results primarily in diarrhoea, but in some cases more serious clinical consequences may result.

Clostridium botulinum
Clostridium botulinum intoxication results in serious clinical consequences, with 80% of cases requiring hospitalisation. Fortunately disease caused by this organism is very rare in New Zealand, the last known case in New Zealand was in 1984. Cases are usually associated with inadequate canning or bottling because the organism can grow and produce toxin under anaerobic conditions. Historically, a number of overseas outbreaks occurred when home canning was common.

Clostridium perfringens
Clostridium perfringens produces a toxin in the intestine that results in diarrhoea. However, recovery is usually rapid. Typically, intoxications occur as a result of eating foods that have been cooked but then are inadequately cooled or refrigerated allowing spores that survived cooking to germinate and grow to high numbers.

Cryptosporidium parvum
Cryptosporidium parvum is a protozoan parasite that causes gastrointestinal symptoms in humans, especially children. Infection is mostly associated with consumption of contaminated water; however, raw fruits and vegetables and raw milk have been implicated in infections.

Enteric viruses
Enteric Viruses (other than hepatitis A and Noroviruses) are occasionally involved in food poisonings. Rotaviruses, for example, are a major cause of childhood gastroenteritis worldwide. Large outbreaks of rotavirus infections involving thousands of cases have occurred overseas. Contaminated school lunches were implicated.

Escherichia coli O157:H7
Escherichia coli O157:H7 infections can result in a range of clinical outcomes; from mild diarrhoea to death. While disease caused by this organism occurs in New Zealand at rates similar to those found in other countries, only one case in New Zealand has been associated with food, albeit non-regulated food.

Escherichia coli : non-O157 shiga toxin-producing (STEC)
Non-O157 shiga toxin-producing Escherichia coli (STEC) are a diverse group of E. coli serotypes defined by the production of shiga-like toxins. Outbreaks due to these organisms have not been recorded in New Zealand, but they have occurred overseas. The clinical consequences of infection may be serious, including kidney failure and death, especially in children.

Giardia intestinalis
Giardia intestinalis is a protozoan parasite. Infection in humans occurs one to three weeks after consumption, and symptoms can last from four to six weeks. Infection is most often associated with the consumption of contaminated water, although food can be involved, as can person-to-person transmission.

Hepatitis A virus
Hepatitis A virus causes a severe disease that can be food or waterborne. Outbreaks in New Zealand are rare, but in one example 36 people were infected after an unwell food handler contaminated food. Humans are the major reservoir of the virus.

Listeria monocytogenes
Listeria monocytogenes infections are serious, with an overall case fatality rate of around 20% in the most serious form of the disease. Fortunately cases are rare, usually there are less than 20 per year in New Zealand. Because Listeria can grow at refrigeration temperatures, foods associated with the organism tend to be those with long shelf lives that are stored under refrigeration. The organism is widespread and while most people ingest small numbers daily without subsequent illness, at-risk groups of the population may become ill when ingesting higher numbers.

Mycobacterium bovis
Mycobacterium bovis is a rare, but serious, cause of infection in New Zealand. The pasteurisation of milk, and control of infected ruminant animals, have been very effective in controlling the organism. The last outbreak attributed to contaminated milk occurred in 1959 in the UK.

Norwalk-like viruses
Noroviruses (previously known as Norwalk-like viruses) are the cause of many cases of gastrointestinal disease in New Zealand. Person-to-person spread is very common. Food can be contaminated through poor hygiene practices among food handlers or, in the case of some shellfish outbreaks, because the food has been grown in a contaminated environment.

Salmonella Typhi
Salmonella Typhi infections result in typhoid fever. This is a serious disease, with 75% of cases requiring hospitalisation. Cases are rare in New Zealand and usually occur in people returning from overseas travel. However, one case in 1996 has been associated with, although not definitively linked to, the consumption of raw shellfish, harvested non-commercially.

Salmonellae : Non-typhoid
Non-typhoid Salmonellae cause salmonellosis. These infections are the second most frequently notified enteric infections in New Zealand. A diverse range of foods may carry the organism and, overseas, even contaminated potato chips have resulted in a large outbreak. The organism survives drying well, and is less sensitive to heat treatment when present in dry foods.

Scombroid (histamine) poisoning
Scombroid (histamine) poisoning results when scombroid fish, such as Kahawai, tuna and mackerel, are not handled or chilled appropriately. When this occurs bacteria convert amino acids into biogenic amines which, when eaten, cause allergic symptoms such as rashes and skin inflammation. Heating does not destroy these amines. Such food poisonings occur most often after the consumption of fish, but other foods such as cheese may also contain elevated levels of biogenic amines under some circumstances.

Shigella
Shigella infections result in bacillary dysentery. Humans are the primary reservoir of the organism and foods may become contaminated directly from infected people or via contaminated water. Typically outbreaks occur where cooked or raw foods served cold, are the vehicle.

Staphylococcus aureus
Staphylococcus aureus produces a heat-stable toxin in food that, when ingested, typically results in abdominal cramps and vomiting. Humans carry the organism in moist areas such as the nose or in skin lesions. Poor hygiene may result in contamination of cooked foods, and temperature abuse allows the organism to grow and produce toxin. Outbreaks in New Zealand have involved foods as diverse as yoghurt, ham and freeze-dried meals.

Toxoplasma gondii
Toxoplasma gondii is a protozoan parasite that can produce disease in humans resulting in very mild symptoms to miscarriages resulting in the death of the foetus. Cats are part of the life cycle of the parasite and it is shed in their faeces. Cysts may also occur in the muscle tissue of meat animals, consumption of which can result in infection. The incidence of disease in New Zealand is not known.

Vibrio cholerae
Vibrio cholerae causes cholera. In the developed world, most cases are associated with the consumption of seafood and is usually due to serotypes that cause a less severe disease than that associated with the classical water-borne pandemics that occur in Asia. Cases are rare in New Zealand.

Vibrio parahaemolyticus
Vibrio parahaemolyticus is associated with food poisonings following seafood consumption. The incidence in New Zealand is not known, but cases have followed the consumption of seafoods imported from South Pacific islands. Shellfish often contain the organism at low, harmless, numbers and overseas studies indicate that most often contamination is by non-pathogenic forms of the organism.

Vibrio vulnificus
Vibrio vulnificus is a rare cause of disease in New Zealand. The consequences of infection are serious, and death can occur swiftly after the onset of symptoms. Shellfish grown in warm waters can carry the organism. Most cases occur in at risk groups; often those with impaired liver function.

Yersinia enterocolitica
Yersinia enterocolitica causes the third most frequently notified enteric disease in New Zealand. Pathogenic types of the organism are associated with pigs, and pork products are regarded as being associated with disease. Pork consumption was identified as a risk factor in an Auckland case control study. Foods implicated in outbreaks overseas are diverse; from dairy products to tofu.