LISTERIA MONOCYTOGENES

Listeria Monocytogenes

Listeria monocytogenes

Introduction

Listeria monocytogenes are bacterium widely spread in nature. Their presence in food is determined by its extensive distribution in the environment like soil, sewage, feces, vegetation, silage and environment of food production. This gives a valuable opportunity to contaminate them. Listeriosis is a food-borne disease that presents as sporadic cases or outbreaks, the literature presents abundant documentation it was possible to establish the transmitter contaminated food. It is an infectious disease caused by rod-shaped bacteria (Listeria).

Listeria monocytogenes are gram-positive rod-shaped bacteria that can multiply aerobically or anaerobically. The culture is best done on blood agar plates. There they form small gray-white colonies, which can be surrounded by a small b-Hamolysezone. Listeria flagella are forming, but not from spore and capsule. In the environment, they are widespread. They are found especially in animal faeces, contaminated water and soil. For most people, they go through the food chain. Approximately 10% of healthy people they are detected in the intestine. Their resistance is relatively large. They are relatively resistant to heat and can even at low temperatures (4 ° C) to survive (Goldfine, 2007).

Discussion

Its existence

This infection occurs worldwide but is rarely diagnosed. Listeria monocytogenes, has long been recognized as a pathogen of animals, causes basilar meningitis (rotating disease) and stillbirth in sheep and cattle. The emergence of listeriosis in humans is under increasing attention as it has recognized the importance of contaminated food disease outbreaks.

The invasive listeriosis (confirmed by blood culture or cerebrospinal fluid [CSF]) affects each year at a rate of three to five people per million individuals in the usual U.S. population. The variant prenatal complication arises as nine out of 100 000 live births. Many cases of Listeria monocytogenes disease are sporadic, but the investigation of outbreaks of food-borne disease has demonstrated a common origin and an average incubation period of two to six weeks after consuming contaminated products (Beumer, 1997).

The Affects

Until the 1970s, Listeria monocytogenes as a problem were mainly in the keeping of farm animals, which are mainly encephalitis and caused miscarriages. By the early 1980s, the bacterium, however, gained increasing importance as pathogens in humans. Listeria monocytogenes are pathogenic for numerous animal species. In humans, there is no specific clinical picture. The pathogens are classic opportunist. In immunocompetent patients, the infection is usually silent or mild flu-like symptoms. By contrast, the pathogens in patients with severe immune deficiency infection (especially sepsis, encephalitis) cause. Listeriosis during pregnancy can lead to miscarriage or congenital listeriosis. The incidence of serious infections is estimated at six cases per million population per year. In most cases, infections from raw milk (cheese), raw or smoked fish from raw sausages. Listeria monocytogenes produce a toxin (listeriolysin), which causes blood agar plates b-hemolysis. The virulence can vary from tribe to tribe. For the pathogenesis, of the survival of bacteria in phagocyte and other cells is critical. It can cause abortions, meningoencephalitis and meningitis especially infants, and elderly, and bacteria in pregnant women and neonates (infant-septic ...