Salmonella typosa

Salmonella
Scientific classification
Superkingdom:	Bacteria
Kingdom:	Bacteria
Phylum:	Proteobacteria
Class:	Gammaproteobacteria
Order:	Enterobacteriales
Family:	Enterobacteriaceae
Genus:	Salmonella Lignieres 1900
Species
S. bongori S. enterica

Salmonella  is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions (i.e. peritrichous). They are chemoorganotrophs, obtaining their energy from oxidation and reduction reactions using organic sources, and are facultative anaerobes. Most species produce hydrogen sulfide,^[1] which can readily be detected by growing them on media containing ferrous sulfate, such as TSI. Most isolates exist in two phases: a motile phase I and a nonmotile phase II. Cultures that are nonmotile upon primary culture may be switched to the motile phase using a Cragie tube.^{[citation needed]}
Salmonella is closely related to the Escherichia genus and are found worldwide in cold- and warm-blooded animals (including humans), and in the environment. They cause illnesses like typhoid fever, paratyphoid fever, and the foodborne illness.^[2]
Salmonella is typically pronounced with the initial letter "L," although it is named for pathologist Daniel Elmer Salmon.
Salmonella infections are zoonotic and can be transferred between humans and nonhuman animals. Many infections are due to ingestion of contaminated food. A distinction is made between enteritis Salmonella and typhoid/paratyphoid Salmonella, where the latter — because of a special virulence factor and a capsule protein (virulence antigen) — can cause serious illness, such as Salmonella enterica subsp. enterica serovar Typhi. Salmonella typhi. is adapted to humans and does not occur in animals.

• Enteritis Salmonellosis or Food Poisoning Salmonella

This is a group consisting of potentially all other serotypes (over a thousand) of the Salmonella bacterium, most of which have never been found in humans. These are encountered in various Salmonella species, most having never been linked to a specific host, and can also infect humans. It is therefore a zoonotic disease. The organism enters through the digestive tract and must be ingested in large numbers to cause disease in healthy adults. Gastric acidity is responsible for the destruction of the majority of ingested bacteria. The infection usually occurs as a result of massive ingestion of foods in which the bacteria are highly concentrated similarly to a culture medium. However, infants and young children are much more susceptible to infection, easily achieved by ingesting a small number of bacteria. It has been shown that, in infants, the contamination could be through inhalation of bacteria-laden dust. After a short incubation period of a few hours to one day, the germ multiplies in the intestinal lumen causing an intestinal inflammation with diarrhoea that is often muco-purulent and bloody. In infants, dehydration can cause a state of severe toxicosis. The symptoms are usually mild. There is normally no sepsis, but it can occur exceptionally as a complication in weakened elderly patients (Hodgkin's disease, eg.). Extraintestinal localizations are possible, especially Salmonella meningitis in children, osteitis, etc. Enteritis Salmonella (e.g., Salmonella enterica subsp. enterica serovar enteritidis) can cause diarrhoea, which usually does not require antibiotic treatment. However, in people at risk such as infants, small children, the elderly, Salmonella infections can become very serious, leading to complications. If these are not treated, HIV patients and those with suppressed immunity can become seriously ill. Children with sickle cell anaemia who are infected with Salmonella may develop osteomyelitis.
In Germany, Salmonella infections must be reported.^[3] Between 1990 and 2005, the number of officially recorded cases decreased from approximately 200,000 cases to approximately 50,000. It is estimated that every fifth person in Germany is a carrier of Salmonella. In the USA, there are approximately 40,000 cases of Salmonella infection reported each year.^[4] According to the World Health Organization, over 16 million people worldwide are infected with typhoid fever each year, with 500,000 to 600,000 fatal cases.
Salmonella can survive for weeks outside a living body. They have been found in dried excrement after more than 2.5 years.^{[citation needed]} Salmonella are not destroyed by freezing.^[5][6] Ultraviolet radiation and heat accelerate their demise; they perish after being heated to 55 °C (131 °F) for one hour, or to 60 °C (140 °F) for half an hour.^{[citation needed]} To protect against Salmonella infection, it is recommended that food be heated for at least ten minutes at 75 °C (167 °F) so that the centre of the food reaches this temperature.^[7][8]
The AvrA toxin injected by the type three secretion system of Salmonella typhimurium works to inhibit the innate immune system by virtue of its serine/threonine acetyltransferase activity and requires binding to eukaryotic target cell phytic acid (IP6).^[9] This leaves the host more susceptible to infection. In a 2011 paper,^[10] Yale University School of Medicine researchers described in detail how Salmonella is able to make these proteins line up in just the right sequence to invade host cells. "These mechanisms present us with novel targets that might form the basis for the development of an entirely new class of anti-microbials," said Professor Dr. Jorge Galan, senior author of the paper and the Lucille P. Markey Professor of Microbial Pathogenesis and chair of the Section of Microbial Pathogenesis at Yale. In the new National Institutes of Health (NIH)-funded study, Galan and colleagues (Maria Lara-Tejero, Junya Kato, Samuel Wagner, and Xiaoyun Liu) identify what they call a bacterial sorting platform, which attracts needed proteins and lines them up in a specific order. If the proteins do not line up properly, Salmonella, as well as many other bacterial pathogens, cannot "inject" them into host cells to commandeer host cell functions, the lab has found. Understanding how this machine works raises the possibility that new therapies can be developed which disable this protein delivery machine and therefore thwart the ability of the bacterium to become pathogenic. The process would not kill the bacteria as most antibiotics do, but would cripple its ability to do harm. In theory, this means that bacteria such as Salmonella might not develop resistance to new therapies as quickly as they usually do to conventional antibiotics.