Campylobacter infection: cause, effect and prevention

1. Campylobacter SPP are microorganisms that can cause infectious diseases. C. jejuni, C. coli, C. upsaliensis and C. lari are species of the Campylobacteriaceae family. 80-90% of Campylobacteriosis cases are caused by Campylobacter jejuni. Campylobacter receives less attention in the media than, say, Listeria or Salmonella due to the fact that an infection caused by Campylobacter rarely leads to death.

Morphology

1. Morphology means geometry, the morphological properties are the external characteristics by which a micro-organism can be recognized. The most relevant species from the Campylobacteriaceae family is C. jejuni, the name jejuni comes from the middle part of the small intestine. C. jejuni is a gram-negative bacterium, gram-negative means that after staining the bacterium gets a pink color. Campylobacter is highly mobile and has the shape of a rod with a flagella at the end. Campylobacter species do not form spores, have a size of approximately 0.2-0.8 μm in diameter and 0.5-5 μm in length. Not all Campylobacter species are rod-shaped, some species have a curved shape, spiral or coccoid shape. The coccoid-shaped Campylobacter are immobile and uncultivable.

Contamination

1. Campylobacter occurs in many places in nature, so contamination does not always occur via the same route. Animals such as rodents, sheep, flies, pigs, pigs, cattle and poultry can be infected with Campylobacter. See the table for the most common sources.

Prevention: factors for growth, survival and killing of Campylobacter

1. Every person needs oxygen for energy metabolism, this is not always the case with micro-organisms. In addition to oxygen, temperature, a W value, nutrition and pH are important for the survival and growth of microorganisms. By reducing or removing one of the factors that are important, growth of a microorganism can be slowed or stopped. We call it a hurdle to make it more difficult for a micro-organism to grow. The more hurdles there are, the more difficult it is for a micro-organism to grow or survive. We call the raising of hurdles conservation. Which hurdles are applied depends on the product and the micro-organism. Important hurdles for Campylobacter are oxygen, temperature, pH and the a W value.

Oxygen

1. The presence or absence of oxygen is important for microorganisms. Some microorganisms grow well in the presence of oxygen, but can also grow in the absence of oxygen. We call a micro-organism that can grow with both oxygen (aerobic) and without oxygen (anaerobic). That's all Enterobacteria, including Salmonella.

Temperature

1. The optimal temperature for growth is strain dependent, the thermophilic species such as coli, jejuni, lari and upsaliensis require a minimum temperature of 30 ° C, the optimal temperature for mesophilic species is 37 ° C and for themophilic species 42 ° C. This can be explained by the higher temperature in the intestines of chickens, for example. The maximum temperature is between 45-55 ° C. Cooling a product prevents Campylobacter from growing. Animal products are primarily a risk for Campylobacter, so always keep fresh meat <7 ° C.

PH

1. How well Campylobacter can grow also depends on the pH. The minimum pH for growth is 4.9. The optimal pH is between 6.5 and 7.5. The maximum pH is 9.0, but the upper limit is not very relevant because there are few products with a high pH. The lower limit is most important for preserving products. By lowering the pH in combination with other hurdles, such as a W and preservatives, growth can be inhibited. The pH can be lowered by, for example, adding lemon juice to a product. In some cases the taste will change undesirably. Proteins can also denature when the pH is lowered, causing fish and meat to discolour. So lowering the pH is not always a good option.

Water activity a W value

1. The a W value indicates how much water is available for reactions or for micro-organisms. The a W value of pure water is 1, in a product with an a W value of 1 the water molecules are bound to the product just as strongly as in pure water the molecules are bound to each other. Substances such as salt and sugar bind water and lower the a W value. The lower the a W value, the less water is available. The amount of water in a product is not important, meat with 65% water (a W value 0.95) can spoil just as quickly as a product with 80% water (a W value 0.95). The minimum a W value that Campylobacter needs for growth is 0.97. The a W value can be reduced with salt. As an example: 10 grams of salt in 150 ml of water lowers the a W value from 1 to 0.96. 10 grams of salt in 150 ml of water gives a salt concentration of 6.6%, which is two times higher than the concentration of salt in seawater. In general, more than 2% salt in a product is not tasty, the salty taste can be masked by adding fat. The a W value can be reduced by freezing meat. The a W value decreases during freezing because ice crystals are formed in the free water. The ice crystals formed are no longer available to microorganisms.

Kill

1. Campylobacter is not very thermoresistant, a mild heat treatment is sufficient to kill Campylobacter. The D value at 70 ° C is on average 6.6 seconds. That is, 6.6 seconds at 70 ° C will result in 1 decimal reduction. Example: if a chicken fillet contains 100,000 = 10 5 bacteria (colony forming units = CFU) per gram, then 6.6 seconds at 70 ° C will reduce the number of bacteria (CFU) by 1 log. That means that from 10 5 CFU has gone to 10 4 CFU. For a chicken fillet with 105 CFU / g, a heat treatment of 33 seconds on average at a core temperature of 70 ° C is sufficient.

Disease symptoms

1. People can become ill by consuming contaminated food. Campylobacter bacteria that survive the gastric passage then penetrate the mucus layer of the intestine with the help of their flagella. Infection with Campylobacter does not always lead to disease symptoms, in most cases you will not notice an infection. If symptoms occur, they are the result of inflammation in the intestine. Inflammation can take place in the colon, jejunum, or ileum. Gastroenteritis is common in infectious microorganisms, including Campylobacter. The symptoms that may occur are headache, fever, flu-like symptoms, muscle pain, stomach pain, nausea, vomiting and bloody diarrhea. The incubation period is usually from 72 hours, the gastrointestinal complaints usually last about 1 day to a week. Elimination of Campylobacter in the faeces can take 2 to 7 weeks. With a Campylobacter infection a recurrence in the intestine can occur if the inflammation is not treated, this is the case in 5 to 10% of the infections. [! 159649 => 1130 = 1890!] Increased probability

1. The YOPIs, young, older, pregnant and immuno-compromised have an increased risk of infection. That counts for:

Post-infectious complications

1. Postinfectious complications are symptoms that occur after the acute infection has disappeared. Reactive arthritis and Guillain-Barré syndrome can occur. Up to about 20% of patients with Campylobacter infection may experience joint complaints.

Epidemiology

1. Based on the culture data, the RIVM estimates the annual number of cases of gastroenteritis caused by Campylobacter in the Netherlands. In 2006 it was estimated that 80,000 people a year get gastroenteritis from Campylobacter. Of these, 18,000 go to the doctor because of the symptoms. In the summer, the number of infections peaks in the Netherlands, just as in other countries with a moderate climate. More than 600 patients are admitted to a hospital every year, of which ± 30 die. The YOPIs are especially vulnerable and have an increased risk of a serious infection course.