''Salmonella bongori'' is a

pathogen In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...

bacterium Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the ...

belonging to the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Salmonella ''Salmonella'' is a genus of bacillus (shape), rod-shaped, (bacillus) Gram-negative bacteria of the family Enterobacteriaceae. The two known species of ''Salmonella'' are ''Salmonella enterica'' and ''Salmonella bongori''. ''S. enterica'' ...

'', and was earlier known as ''Salmonella''

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

V or '' S. enterica'' subsp. ''bongori'' or ''S. choleraesuis'' subsp. ''bongori''. It is a

gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

, rod-shaped bacterium (bacillus), which causes a gastrointestinal disease called

salmonellosis Salmonellosis is a symptomatic infection caused by bacteria of the ''Salmonella'' type. It is the most common disease to be known as food poisoning (though the name refers to food-borne illness in general). These are defined as diseases, usuall ...

, characterized by cramping and

diarrhoea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

. It is typically considered a

microbe A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...

of cold-blooded animals, unlike other members of the genus, and is most frequently associated with

reptiles Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

. It was discovered in 1966 from a

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

in the city of Bongor,

Chad Chad, officially the Republic of Chad, is a landlocked country at the crossroads of North Africa, North and Central Africa. It is bordered by Libya to Chad–Libya border, the north, Sudan to Chad–Sudan border, the east, the Central Afric ...

, from which the specific name ''bongori'' was derived. After decades of controversy in ''Salmonella'' nomenclature, it gained the

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

status in 2005.

Pathogenicity and epidemiology

''S. bongori'' is classically regarded as the ''Salmonella'' of lizards. However, discrete investigations contradict the notion of strict host-specificity, as reports emerged of occurrence in

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. ...

s and

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s. In animals, unlike those of other ''Salmonella'', infection is generally

asymptomatic Asymptomatic (or clinically silent) is an adjective categorising the medical conditions (i.e., injuries or diseases) that patients carry but without experiencing their symptoms, despite an explicit diagnosis (e.g., a positive medical test). P ...

and does not cause discernible effects. However, infection of pet animals is associated with diarrhea. Further, human infections have been substantiated, with conclusive reports from Italy. The majority of these cases are among children less than 3 years old, who are more prone to oral contact with animal droppings. Symptoms are typified by diarrhoea with

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

and acute

enteritis Enteritis is inflammation of the small intestine. It is most commonly caused by food or drink contaminated with pathogenic microbes,Dugdale, David C., IIII, and George F Longretc"Enteritis" MedlinePlus Medical Encyclopedia, 18 October 2008. Acces ...

. The first observations, from

Messina Messina ( , ; ; ; ) is a harbour city and the capital city, capital of the Italian Metropolitan City of Messina. It is the third largest city on the island of Sicily, and the 13th largest city in Italy, with a population of 216,918 inhabitants ...

and

Palermo Palermo ( ; ; , locally also or ) is a city in southern Italy, the capital (political), capital of both the autonomous area, autonomous region of Sicily and the Metropolitan City of Palermo, the city's surrounding metropolitan province. The ...

, starting from late 1984, were followed by other cities in

Sicily Sicily (Italian language, Italian and ), officially the Sicilian Region (), is an island in the central Mediterranean Sea, south of the Italian Peninsula in continental Europe and is one of the 20 regions of Italy, regions of Italy. With 4. ...

Origin and evolution

Originally ''S. bongori'' was considered to be a subspecies within the genus ''Salmonella''. However, based on DNA similarity, all members of ''Salmonella'' are now grouped into only two species, namely ''S. bongori'' and ''S. enterica''. Species of ''Salmonella'' are closely related to '' E. coli'' and they are estimated to have diverged from a common ancestor about 100 million years ago; their

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

s still display significant similarity, hence many functional identities. Many of the

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

s which are unique to ''Salmonella''

serovar A serotype or serovar is a distinct variation within a species of bacteria or virus or among immune cells of different individuals. These microorganisms, viruses, or cells are classified together based on their shared reactivity between their ...

s, compared to ''E. coli'', are found on large discrete genomic islands such as ''Salmonella'' pathogenicity islands (SPIs). These ''Salmonella''-specific functions include many genes for their

virulence Virulence is a pathogen's or microorganism's ability to cause damage to a host. In most cases, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its abili ...

and characterize the

divergence In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the rate that the vector field alters the volume in an infinitesimal neighborhood of each point. (In 2D this "volume" refers to ...

of ''S. enterica'' from ''S. bongori''. For instance, the ''SPI-2'' gene which encodes type III secretion systems present in ''S. enterica'' is absent in ''S. bongori''. Also, the virulence determinants, specifically effector proteins, are indicated to be more closely related to enteropathogenic ''E. coli'' because some of the gene are missing in ''S. enterica''.

References

External links

Taxonomy at UniProt

Biography at Bacmap Genome Atlas

Classification at Encyclopedia of Life

Taxonomy at NCBI

Nomenclature at the Leibniz-Institut DSMZ - Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH

Type strain of ''Salmonella bongori'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q6176438 bongori Gram-negative bacteria