''Salmonella bongori'' is a

pathogen In biology, a pathogen ( el, πάθος, "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 ...

bacterium Bacteria (; singular: 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 ...

belonging to the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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

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

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

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

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

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

salmonellosis Salmonellosis, more commonly known as food poisoning is a symptomatic infection caused by bacteria of the ''Salmonella'' type. It is also a food-borne disease and are defined as diseases, usually either infectious or toxic in nature, caused by a ...

, characterized by

cramping A cramp is a sudden, involuntary, painful skeletal muscle contraction or overshortening associated with electrical activity; while generally temporary and non-damaging, they can cause significant pain and a paralysis-like immobility of the aff ...

and

diarrhoea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

. It is typically considered a

microbe A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

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

reptiles Reptiles, as most commonly defined are the animals in the Class (biology), class Reptilia ( ), a paraphyletic grouping comprising all sauropsid, sauropsids except birds. Living reptiles comprise turtles, crocodilians, Squamata, squamates (lizar ...

. It was discovered in 1966 from a

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

in the city of

Bongor Bongor ( ar, بونقور) is a city in Chad, the capital of the region of Mayo-Kebbi Est. It is located on the eastern bank of the Logone River. During the rainy season (May–September), the Logone is navigable between Bongor and N'Djamena, Cha ...

Chad Chad (; ar, تشاد , ; french: Tchad, ), officially the Republic of Chad, '; ) is a landlocked country at the crossroads of North and Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic ...

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

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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 wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

s and

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

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

asymptomatic In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered asy ...

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 Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...

. Symptoms are typified by diarrhoea with

fever Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...

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. Access ...

. The first observations, from

Messina Messina (, also , ) is a harbour city and the 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 more than 219,000 inhabitants in ...

and

Palermo Palermo ( , ; scn, Palermu , 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 ...

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

Sicily (man) it, Siciliana (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = Ethnicity , demographics1_footnotes = , demographi ...

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 In the fields of molecular biology and genetics, 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 ge ...

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

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

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 surface antigens, allowing the epi ...

s, compared to ''E. coli'', are found on large discrete

genomic island A genomic island (GI) is part of a genome that has evidence of horizontal origins. The term is usually used in microbiology, especially with regard to bacteria. A GI can code for many functions, can be involved in symbiosis or pathogenesis, an ...

s 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, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its ability to ca ...

and characterize the

divergence In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the quantity of the vector field's source at each point. More technically, the divergence represents the volume density of the ...

of ''S. enterica'' from ''S. bongori''. For instance, the ''SPI-2'' gene which encodes

type III secretion system The type III secretion system (T3SS or TTSS), also called the injectisome, is one of the bacterial secretion systems used by bacteria to secrete their effector proteins into the host's cells to promote virulence and colonisation. The T3SS is a ...

s 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