Salmonella Enteritidis (Salmonella enterica sub-specie)

can cause gastrointestinal infections referred to as salmonellosis. The pathogen occurs naturally in the gastrointestinal tract of animals such as pigs, , birds, rodents, reptiles and insects. They spread in the through the faeces of these animals. People can contract salmonellosis when they consume foods contaminated with Salmonella bacteria. Persons who contract salmonellosis remain a carrier / excretory of Salmonella bacteria for a long time (6 – 8 weeks).

ParameterFeatures
Gram
TypeRod
D valueD60 = 1-10 min
Oxygen demand (O2)fa
, rounded5-50
pH (acidity)4-9
Min. aw0.94
Drought
Incubation time8 – 72 hours
Expensive1 – 3 days
Dose-Response relationship DR> 100 000 (sometimes 10)
Food poisoning (VV) / Food infection (VI)VI
SymptomsDiarrhoea, nausea, vomiting, headache, fever, stomach pain
ProductsPoultry, eggs, raw , , vegetables
Sourcewww.fimm.nl
Other information sheetsBad Bug book FDA
Knowledge sheets Dutch Food Authority
NZFSA
Salmonella Typhimurium
Related 2160-2003 Control Salmonella-zoonotic agent
Study Status of food safetySalmonella in Polish eggs
Salmonella in vegetable products
RIVM ReportsSalmonella workshop 2018
Salmonella chicken feed

Taxonomy

Salmonella bacteria belong to the species Salmonella enterica (S. enterica). This species belongs to the Enterobacteriaceae family. They can grow with or without oxygen. They are Gram-negative and have flagella (whip threads) with which they can move in a fluid. Usually, S. enterica bacteria are further designated based on the immunological composition of the cell wall and the flagella present on it. In total, slightly more than 2000 immunological types, also called serotypes, are known. Each serotype has its name, usually a place name where the organism was first isolated. The serotypes are written as follows: Salmonella Agona (S. Agona). Agona is a place in Ghana.

Growth

Salmonella bacterial growth takes place within several . These limits are listed in Table 1.

Table 1. Limits within which S. enterica can grow.

ParameterReported Values ​​
Temperature
Minimum temperature5.2 ºC
Maximum temperature45-46 ° C
Water activity (aw)
Minimum aw0.94
pH
Minimum pH4.2
Optimum pH6.5 – 7.5
Maximum pH9.5

Table 2 provides data on the survival and resistance of S. enterica. The organisms survive for a long time in products and survive for quite a long time in dry products such as chocolate and milk powder. The heat resistance is usually expressed in the time (minutes or seconds) it takes to achieve a 10-fold reduction at a specific temperature. For , a D60.0 value of 7.5 min means that the containing the micro-organisms must be heated for 7.5 minutes at 60.0 o C to reduce the number of S. enteric organisms present by a factor of 10. to reduce. To reduce the organisms present by 100, the pathogen must be at 60.0°C and heated for 2 x 7.5 = 15 minutes.

Table 2. Survival and resistance S. enterica

SurvivalTime
Frozen productsYears
Dry productsMonths
Resistance
Heat D57.2 (sucrose solution)95 min
Heat D60.0 (NaCl solution)7.5 min
Heat D60.0(pea soup)
Heat D60.0(egg product, pH 8.0)
Heat D60.0(egg product, pH 5.5)
Heat D65.5(milk)

It should be noted that there can be significant differences in heat sensitivity between the various serotypes. However, the composition and the pH of the product in which S. enterica is present also determine to a large extent the resistance to heating (see table 2). The most heat-resistant S. enterica is the serotype S. Senftenberg.

Illness and symptoms

The illness usually occurs between 10 to 48 hours after Salmonella ingestion and usually lasts 3-6 days. The main disease symptoms are:

  • Nausea and vomiting;
  • Abdominal pain and diarrhoea;
  • Fever and headache;
  • After 3-4 weeks, the joints can sometimes start to hurt.

People of all age groups can contract salmonellosis. In young children, the elderly (> 70 years) and people with weakened immunity, the disease manifest itself to a more serious degree and medical attention is often necessary.

Salmonellosis-associated foods

  • Raw meat and poultry meat;
  • Eggs, raw milk and products made from raw milk;
  • , shrimp and frog legs;
  • Salad dressings and (with cream) filled pastries;
  • Cocoa and chocolate;
  • Seed sprouts, vegetables and .

General Prevention

  • Keep eggs and raw (meat, fish, poultry meat) refrigerated;
  • Do not use cracked or dirty eggs; – Avoid cross- between raw and prepared products; – After with raw meat and egg contents, kitchen utensils and hands should be washed with a hot soap solution; – During baking and roasting, use a calibrated temperature gauge to measure the internal temperature of meat and poultry meat; – Only use pasteurized products (dairy, liquid egg products and fruit juices).

Incidence

Incidence in the Netherlands. In the Netherlands, 35,000 – 50,000 people contract salmonellosis every year. This equates to approximately 206-290 cases per 100,000 persons per year. Salmonella contaminated eggs, pork, and poultry products are the primary sources of infection. In the United States, the incidence is identical.