ESCHERICHIA COLI

Escherichia coli

Escherichia coli

Introduction

Escherichia coli, also called E. coli, is a bacterium which normally lives in the intestine of mammals, and its presence may indicate aspects of the quality of water and food. E. coli can also cause diseases such as urinary tract infections, diarrhea and hemorrhagic colitis and hemolytic uremic syndrome. The Escherichia coli is a rod-shaped bacteria and is facultative anaerobic. Its primary habitat is the gastrointestinal tract of humans and other endothermic (“warm-blooded”) animals. It is considered as an indicator of water quality and food belonging to the family of faecal coliform: a name given to a group of bacteria that inhabit the intestine of the mammals. Large numbers of this group is formed by Escherichia coli and, thus, their presence suggests the possibility of having, at that location, micro-organisms capable of causing intestinal disorders.

Usually the bacteria in question inhabit the intestine without causing health problems. However, when it is running into the bloodstream or other body regions, it is able to cause infection. This framework can also be manifested by the ingestion of food or water containing strains of bacteria, released with the faeces of infected individuals, by making contact with sick animals, and health care workers or contaminated medical instruments. Moreover, for some health problem, the host itself can allow bacteria to trigger the disease. This paper aims at discussing the main features of Escherichia coli, while exploring its growth characteristics in order to determine its role in food production and environmental processes.

Discussion

E. coli naturally evolves to overcome the adverse conditions they encounter, which explains the existence of so many varieties of the same bacterial species. They can develop the ability to produce toxic substances, as well as those that facilitate their invasion and / or adherence to the host epithelium. These bacteria are also able to produce cellular components that hinder their elimination by the host immune system, or to facilitate their accession, and transmission of genetic information between individuals. All these characteristics aid in determining the degree of virulence and pathogenicity.

Among its variants, the JV is responsible for the outbreak of Entero-haemorrhagic in Europe. This, identified as O104: H4, causes hemorrhagic colitis and hemolytic uremic syndrome. In the latter case, by virtue of the action of their toxins, it causes destruction of the epithelium of the intestine, and rupture of the vessels found there and nephrons (responsible for the filtration of blood in the kidneys). The frame can trigger acute renal failure, and even more serious cases, seizures, and severe problems in the nervous system. Like most infections, children and the elderly are naturally more vulnerable to developing such symptoms, with slightly higher incidence in females.

Growth Characteristics of E. coli

Growth, and survival, of E. coli in food depends, as for all bacteria, upon the interaction of various factors, both intrinsic and extrinsic factors, including the cited pH and temperature. The E. coli survives at low pH, even under pH = 4.0 which is considered the minimum value to allow for microbial ...