Photobacterium Carnosum
   HOME

TheInfoList



OR:

''Photobacterium'' is a genus of
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 ...
, oxidase positive and catalase positive
bacteria 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 ...
in the family ''
Vibrionaceae The Vibrionaceae are a family of Pseudomonadota given their own order, Vibrionales. Inhabitants of fresh or salt water, several species are pathogenic, including the type species ''Vibrio cholerae'', which is the agent responsible for cholera. Mo ...
''. Members of the genus are
bioluminescent Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some Fungus, fungi, microorganisms including ...
, that is they have the ability to emit
light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 tera ...
. Many species, including ''
Photobacterium leiognathi ''Photobacterium leiognathi'' is a species of Gram-negative bacteria. The species is bioluminescent and a symbiont of ponyfish Leiognathidae, the ponyfishes, slipmouths or slimys / slimies, are a small family of fishes in the order Perciformes ...
'' and ''
Photobacterium phosphoreum ''Photobacterium phosphoreum'' or ''Vibrio phosphoreum'' is a Gram-negative bioluminescence, bioluminescent bacterium living in symbiosis with marine organisms, such as anglerfish. It can emit bluish-green light (490 nm) due to a chemical r ...
'', '' Photobacterium ganghwense, Photobacterium marinum'' live in
symbiosis Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
with marine organisms. S.I. Paul et al. (2021) isolated and identified multiple strains of ''Photobacterium'' from marine sponges of the
Saint Martin's Island Saint Martin Island ( bn, সেন্টমার্টিন দ্বীপ) is a small island (area only 3 km2) in the northeastern part of the Bay of Bengal, about 9 km south of the tip of the Cox's Bazar-Teknaf peninsula, and fo ...
Area of the
Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean, bounded on the west and northwest by India, on the north by Bangladesh, and on the east by Myanmar and the Andaman and Nicobar Islands of India. Its southern limit is a line between ...
,
Bangladesh Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mos ...
. Species such as '' Photobacterium profundum'' are adapted for optimal growth in the deep cold seas making it both a
psychrophile Psychrophiles or cryophiles (adj. ''psychrophilic'' or ''cryophilic'') are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from to . They have an optimal growth temperature at . They are found in ...
(an organism capable of growth and reproduction in cold temperatures) and a
piezophile A piezophile (from Greek "piezo-" for pressure and "-phile" for loving) is an organism with optimal growth under high hydrostatic pressure i.e. an organism that has its maximum rate of growth at a hydrostatic pressure equal to or above 10 MPa (= 99 ...
(an organism which thrives at high pressures).


Biochemical characteristics of ''Photobacterium'' species

Colony, morphological, physiological, and biochemical characteristics of ''Photobacterium'' species are shown in the Table below. Note: + = Positive; – =Negative; V =Variable (+/–)


Taxonomy

There are currently 16 species with numerous subspecies known within the genus ''Photobacterium''. The development of 16S RNA sequencing has led to many species being shifted into and out of this genus. ''Photobacterium'' can be distinguished from other genera based on identifiable characteristics.


Identifying characteristics

* Morphological shapes are straight or plump rods * Cell wall structure is classified as gram-negative * Require sodium for growth * Contain 1-3
polar flagella Polar may refer to: Geography Polar may refer to: * Geographical pole, either of two fixed points on the surface of a rotating body or planet, at 90 degrees from the equator, based on the axis around which a body rotates *Polar climate, the cli ...
* Are luminescent * Incapable of forming resistant
endospores An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (''endo'' means 'within'), but it is not a true spore (i.e., no ...
* Are
chemoorganotroph Primary nutritional groups are groups of organisms, divided in relation to the nutrition mode according to the sources of energy and carbon, needed for living, growth and reproduction. The sources of energy can be light or chemical compounds; the ...
s


Ecology

''Photobacterium'' are primarily marine organisms (hence the use of sodium for growth). They may be free-living or found as colonies associated with certain species of fish. These organisms do not contain any pigmentation and therefore will appear white or colorless. When there is a high density of cells forming a colony, they will exhibit fluorescence. However, the fluorescence is based on the accumulation of
autoinducer Autoinducers are signaling molecules that are produced in response to changes in cell-population density. As the density of quorum sensing bacterial cells increases so does the concentration of the autoinducer. Detection of signal molecules by ba ...
s which is proportional to cell density and therefore free-living photobacterium will not fluoresce. Their association with fish may be: symbiotic growth within fish for the formation of light organs, as a neutral entity on the surface or within the intestines of fish, as decomposers of dead fish, or as an agent of disease.


Pathogenicity

Some of the 15 known species of ''Photobacterium'' have evolved into
pathogens 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 ...
of marine life. Some of these diseases affect commercially important fish and can therefore indirectly impact human health through their consumption. This genus has been shown to degrade the
chitin Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chit ...
of the Deep Sea Tanner Crab (''
Chionoecetes ''Chionoecetes'' is a genus of crabs that live in the northern Pacific and Atlantic Oceans. The genus ''Chionoecetes'' currently contains seven distinct species. Other names for crabs in this genus include "queen crab" (in Canada) and "spider ...
tanneri''). The species ''Photobacterium damselae'' are among the most virulent and are divided into two subspecies: '' piscicida'' and ''damsela''. ''P. damselae'' subspecies ''piscicida'' is the causative agent of fish
pasteurellosis Pasteurellosis is an infection with a species of the bacterial genus ''Pasteurella'', which is found in humans and other animals. ''Pasteurella multocida'' (subspecies ''P. m. septica'' and ''P. m. multocida'') is carried in the mouth and respir ...
. Bacterial colonies grow on the infected fish's spleen and kidney, eventually leading to mortality. This disease accounts for severe losses in some fish farming enterprises with some of the most susceptible fish including Yellowfin tuna (''Thunnus albacares''), certain Seabreams (''Sparus'' spp.), Striped bass (''Morone saxatilis''), and White perch (''Morone americana''). This subspecies is not pathogenic for humans.


''Photobacterium damselae'' subspecies ''damsela''

Fish-virulent strains of this subspecies of ''P. damselae'' cause
septicemia Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...
in species of fish such as; damselfish (Family Pomacentridae), eels (''Anguilla anguilla''), sandbar/brown sharks (''Carcharhinus plumbeus''), Yellowtails (''
Seriola quinqueradiata The Japanese amberjack or yellowtail, ''Seriola quinqueradiata'', is a species of jack fish in the family Carangidae. It is native to the northwest Pacific Ocean, ranging from China (called ), Korea (called ), and Japan to Hawaii. It is greatly ...
''), seabreams (''Sparus'' spp.) and turbots (''Scophthalmus'' spp.). This subspecies has been shown to be pathogenic for humans as it has been isolated from human wounds and has been shown to cause primary septicimia in healthy humans.


Symptoms of ''Photobacteria damselae'' subspecies ''damselae''

Fish infected by the subspecies ''damselae'' initially experience a reduced appetite accompanied by lethargicness and ulcerative lesions along their flank and head regions. Their stomachs will distend and they will experience extensive hemorrhaging especially in their eyes, mouth, and musculature. There will also be
petechia A petechia () is a small red or purple spot (≤4 mm in diameter) that can appear on the skin, conjunctiva, retina, and Mucous membrane, mucous membranes which is caused by haemorrhage of capillaries. The word is derived from Italian , 'freckle,' ...
tion of the gills and liver along with the characteristic accumulation of mucus around the gills. It has been noted that the infected fish will swim violently a few minutes before death occurs.


Transmission/infection of ''Photobacterium damselae'' subspecies ''damsela''

Evidence of
epizootic In epizoology, an epizootic (from Greek: ''epi-'' upon + ''zoon'' animal) is a disease event in a nonhuman animal population analogous to an epidemic in humans. An epizootic may be restricted to a specific locale (an "outbreak"), general (an "epi ...
outbreaks gained from an increase in ulcers noted among the fish populations seem to correlate to warmer seasons, suggesting a seasonal distribution in the incidence of the disease, dependent upon the waters temperature and salinity along with a decreased resistance caused by physiological changes experienced by the host during sexual maturity. Seawater is the most likely mode of transmission of the virulent cells of the pathogen. Once it comes into contact with the outer surface of the fish, it is able to adhere to skin and resist the bactericidal action of the skin mucus layer, thus suggesting that the skin is the site of entry into the host. This bacterium could therefore represent a significant threat to aquacultured fish species, especially those living in crowded and stressed conditions, where the spread of the disease could be accelerated through direct contact and thus pose a threat to humans.


See also

* ''
Vibrio fischeri ''Aliivibrio fischeri'' (also called ''Vibrio fischeri'') is a Gram-negative, rod-shaped bacterium found globally in marine environments. This species has bioluminescent properties, and is found predominantly in symbiosis with various marine anim ...
''


References

Hilgarth, Maik et al. “Photobacterium Carnosum Sp. Nov., Isolated from Spoiled Modified Atmosphere Packaged Poultry Meat.” Systematic and Applied Microbiology 41.1 (2018): 44–50.


External sources

* * * {{Taxonbar, from=Q1632556 Vibrionales Bioluminescent bacteria Bacteria genera