''Moraxella osloensis'' 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 ...

oxidase In biochemistry, an oxidase is an enzyme that catalyzes oxidation-reduction reactions, especially one involving dioxygen (O2) as the electron acceptor. In reactions involving donation of a hydrogen atom, oxygen is reduced to water (H2O) or hydro ...

-positive,

aerobic Aerobic means "requiring air," in which "air" usually means oxygen. Aerobic may also refer to * Aerobic exercise, prolonged exercise of moderate intensity * Aerobics, a form of aerobic exercise * Aerobic respiration, the aerobic process of cellu ...

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 ...

within the family

Moraxellaceae The Moraxellaceae are a family of Gammaproteobacteria, including a few pathogenic species.George M. Garrity: '' Bergey's Manual of Systematic Bacteriology''. 2. Auflage. Springer, New York, 2005, Volume 2: ''The Proteobacteria, Part B: The Gamma ...

in the gamma subdivision of the purple bacteria. ''Moraxella osloensis'' is a mutualistic symbiont of the slug-parasitic nematode ''

Phasmarhabditis hermaphrodita ''Phasmarhabditis hermaphrodita'' is a Facultative parasite, facultative parasitic nematode that can kill slugs and snails.Genena, M. A., Mostafa, F. A., Fouly, A. H., & Yousef, A. A. (2011). First record for the slug parasitic nematode, Phasmarh ...

''. In nature, ''Phasmarhabditis hermaphrodita'' vectors ''M. osloensis'' into the shell cavity of the

slug Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a smal ...

host in which the bacteria multiply and kill the slug.

Lifecycle

This bacterium has been identified as one of the natural symbionts of a bacteria-feeding

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

, ''Phasmarhabditis hermaphrodita'' (

Rhabditida Rhabditida is an order of free-living, zooparasitic, and phytoparasitic microbivorous nematodes living in soil. The Cephalobidae, Panagrolaimidae, Steinernematidae, and Strongyloididae seem to be closer to the Tylenchia, regardless of whet ...

Rhabditidae The Rhabditidae are a family of nematodes which includes the model organism '' Caenorhabditis elegans''. Genera ''Bursilla'' *''Bursilla monhysteria'' (Butschli, 1873) ''Caenorhabditis'' *''Caenorhabditis brenneri'' Sudhaus & Kiontke, 2007 ...

), which is an

endoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

of slugs, including the slug ''

Deroceras reticulatum ''Deroceras reticulatum'', common names the "grey field slug" and "grey garden slug", is a species of small air-breathing land slug, a terrestrial pulmonate gastropod mollusc in the family Agriolimacidae. This species is an important agricul ...

'' (grey garden slug) which is one of the most serious agricultural and garden slug pests. In nature, bacteria colonize the gut of nematode-infective juveniles which represent a specialized stage of development adapted for survival in the unfavorable environment. The infective juveniles seek out and enter the slug's shell cavity through the posterior

mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle may refer to: *Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear **Mantle (vesture), an Eastern Orthodox ve ...

region. Once inside the shell cavity, the bacteria are released, and the infective juveniles resume growth, feeding on the multiplying bacteria. The infected slugs die in 4–10 days, and the nematodes colonize the entire carcass and produce next-generation infective juveniles, which leave the carcass to seek a new host. The bacteria are responsible for killing the slugs; nematodes without bacteria do not cause death.

Biochemistry

The

lipopolysaccharide Lipopolysaccharides (LPS) are large molecules consisting of a lipid and a polysaccharide that are bacterial toxins. They are composed of an O-antigen, an outer core, and an inner core all joined by a covalent bond, and are found in the outer m ...

, that is an

endotoxin Lipopolysaccharides (LPS) are large molecules consisting of a lipid and a polysaccharide that are bacterial toxins. They are composed of an O-antigen, an outer core, and an inner core all joined by a covalent bond, and are found in the outer ...

, from ''M. osloensis'' is a

molluscicide Molluscicides () – also known as snail baits, snail pellets, or slug pellets – are pesticides against molluscs, which are usually used in agriculture or gardening, in order to control gastropod pests specifically slugs and snails which damag ...

for ''Deroceras reticulatum'' when applied by

injection Injection or injected may refer to: Science and technology * Injective function, a mathematical function mapping distinct arguments to distinct values * Injection (medicine), insertion of liquid into the body with a syringe * Injection, in broadca ...

. The lethality of these nematodes to slugs has been shown to correlate with the number of ''M. osloensis'' cells carried by infective juveniles. Tan and Grewal (2001) demonstrated that the 72-hour-old ''M. osloensis'' cultures inoculated into the shell cavity were highly pathogenic to the slug. They further reported that ''M. osloensis'' produced an endotoxin which was identified to be a rough type lipopolysaccharide with a molecular weight of 5300 KD, and the purified lipopolysaccharide was toxic to the slug with an estimated 50% lethal dose of 48 μg when injected into the shell cavity.

Infections of humans

Although ''M. osloensis'' rarely infects humans, it can sometimes be found in a variety of tissues, where it sometimes causes disease.

Antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...

s are usually effective against such infections.

Odor

''Moraxella osloensis'' has been found to be responsible for locker-room smell or shower-curtain odor.

Classification

The species ''M. osloensis'' was proposed in 1967; the bacteria which are now considered to be ''M. osloensis'' would previously have been considered to be ''

Moraxella nonliquefaciens ''Moraxella nonliquefaciens'' is a Gram-negative bacterium in the genus ''Moraxella'', which was isolated from the upper respiratory tract The respiratory tract is the subdivision of the respiratory system involved with the process of respir ...

'' or ''

Mima polymorpha ''Acinetobacter lwoffii'', formerly known as ''Mima polymorpha'' or ''Acinetobacter calcoaceticus var. lwoffii'', is a non- fermentative Gram-negative bacillus bacterium that is a member of the genus ''Acinetobacter''. It is considered as normal ...

'' (var.) ''oxidans''.

References

This article incorporates CC-BY-2.0 text from the reference.

External links

Type strain of ''Moraxella osloensis'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q6909429 Moraxellaceae Gram-negative bacteria