''Legionella anisa'' 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 wa ...
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 am ...
, one of more than 40
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 appropriat ...
in the family
Legionellaceae
''Legionella'' is a genus of pathogenic gram-negative bacteria that includes the species '' L. pneumophila'', causing legionellosis (all illnesses caused by ''Legionella'') including a pneumonia-type illness called Legionnaires' disease and a m ...
. After ''
Legionella pneumophila
''Legionella pneumophila'' is a thin, aerobic, pleomorphic, flagellated, non-spore-forming, Gram-negative bacterium of the genus '' Legionella''. ''L. pneumophila'' is the primary human pathogenic bacterium in this group and is the causative ...
'', this species has been isolated most frequently from water samples. This species is also one of the several pathogenic forms of ''Legionella'' having been associated with rare clinical cases of illness including
Pontiac fever and
Legionnaires' disease.
History
This species was first isolated from water during a nosocomial outbreak in the United States between March 1980 and June 1981. The type strain of ''L. anisa'' is WA-316-C3 (ATCC 35292).
The first reported clinical detection was in 1986, with a female patient in
Victoria, Australia
Victoria is a state in southeastern Australia. It is the second-smallest state with a land area of , the second most populated state (after New South Wales) with a population of over 6.5 million, and the most densely populated state in ...
, who presented with pneumonia. Similar to other ''
Legionella'' species, person-to-person transmission has not been documented.
Structure
Like other ''Legionella'' species, ''L. anisa'' is a thin,
aerobic,
pleomorphic,
flagellated, non-spore-forming,
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 wa ...
bacterium. A distinguishing characteristic is the ability of colonies to exhibit blue-white autofluorescence when viewed under ultraviolet light. Thus, ''L. anisa'', along with several other species of ''Legionella'', is sometimes referred to as "blue-white" ''Legionella''.
Detection
''Legionella anisa'' is traditionally detected using the same culture methods as described for ''Legionella''. However, some research suggests ''L. anisa'' may require a co-culture method that accounts for the close relationship with amoebae. When present in a sample but still contained within an amoeba host, the plating method may return false-negative results. Adjusting currently accepted laboratory analysis may be required to better understand the true clinical and environmental prevalence of this particular species.
Genome-based analytical techniques may prove especially useful for ''L. anisa'', as a study of isolates from various locations in France suggest that the genomic variation is much more limited and homogenous than other ''Legionella'' species. In addition, such techniques greatly reduce the time required to obtain results.
Symptoms
Infections may be asymptomatic, and are strongly associated with the
respiratory system
The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies g ...
. Early symptoms can include fever, chills, headache, shortness of breath, cough, muscle aches and pain, fatigue, loss of appetite, sputum production with presence of blood, nausea, and irritation or inflammation of the nose, throat, or lungs.
Most people who breathe in the bacteria do not become ill. The risk of disease is increased with age, smoking, and in people with weakened immune systems. A multinational study found that less than 3% of reported ''Legionella'' infections were due to ''L. anisa''.
References
External links
Public Health England Culture Collection - ''Legionella anisa''Type strain of ''Legionella anisa'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q15252682
Legionellales
Bacteria described in 1985