PROPAGATION OF THE BACTERIA ACCORDING TO TIME AND TEMPERATURE

 

Introduction.

The infection caused by Salmonella is usually caused by eating meat, birds, eggs or products based on it that are raw or little cooked. The bacteria, generally, lives in animal and human intestine, and it is released through feces. This bacterium usually reproduces and develops from a certain time and temperature, bringing consequences to the human body and even epidemics.

Development.

Salmonella belongs to a group of bacteria present in the intestine of healthy people and animals, that is why feces are the main source of contamination of food and water. In consequence, when a person ingests something that is contaminated, it provokes a gastrointestinal infection called “Salmonellosis”.

Usually, the healthy bearer animal are poultry, cattle and pigs, as well as pets. This bacterium can survive several months in water and is also very resistant to the low level of it, which means Salmonella can outlast several weeks in a dry environment.

Salmonella in food

When the bacterium Salmonella is present in food an then it is ingested, usually multiplies itself at a very high velocity, the number increases each 15 or 20 minutes, in case the temperature is high enough, that is, above 20° C. It is known that the optimal growth temperature in food is between 35°C and 43°C.

Does Salmonella develop better in some environments?

It is said that Samonella “develops better on environments rich in nutrients and at room temperature. Its optimal growth temperature in environments is 37°C (which turns out to be the human body temperature). But it can also stay alive in water (rivers o lakes with contaminated with feces)” (Fac. Cs. Químicas y Farmacéuticas, U. Chile, 2011), that represents that the bacterium can spread and survive in many types of environments.

¿Time and Temperature key factors in the growth of Salmonella?

Fresh food that is purchased must be refrigerated quickly in order to stop the bacterium to multiplies and infects another food; this is because the growth limit is at 5.2°C.

	Minimum	Optimal	Maximum
Temperature	5.2	35-43	46.2
Growth in water	0.93	0.99	>0.99

 

Effects on humans

In the European Union, Salmonellosis is the majority cause of outbreaks of food poisoning and gastrointestinal pictures, with at least 100,000 notified cases per year. The EFSA calculates that the cost of the disease is about 3 billion euros per year.

“This illness severity depends on the Salmonella serotype, the amount of bacteria ingested and the immunity system of each infected person” (Elika security in Alemania, 2019), this refers the fact that in each person the severity of contracting Salmonella may vary, because every one of them is different and has no same immune system, which leads to a variation on the recovery time.

The first symptoms cause by Salmonella bacteria appear in approximately 6 to 72 hours, and generally between 12 to 26 hours after consuming a, infected dish. It provokes gastrointestinal pictures with fever, abdominal pain, diarrhea, nausea and in some cases vomit, having a 2 to 7 days of duration.

Salmonellosis is an underdiagnosed disease, which means is a little-known outbreak. 60% and 80% of cases are no registered as known o are not even diagnosed.

Conclusion.

The Salmonella, being a microorganism, depends on several environmental factors, mostly by temperature and time, which grant optimal conditions for the bacterium to carry out processes that allow it to reproduce and incubate, causing its propagation and infecting many individuals. These properties are important to know and measure the spread of Salmonella¸ and its consequent prevention since its infection is easy and barely detected.