Legionella clemsonensis
| Legionella clemsonensis | |
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| Species: | L. clemsonensis
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| Legionella clemsonensis Palmer et al. 2016
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Legionella clemsonensis was isolated in 2006, but was discovered in 2016 by Clemson University researchers.[1] It is a gram-negative bacterium.
Taxonomic and phylogenetic description
“Legionella” is named after the American Legion where the first outbreak occurred killing 34 people and sickening 221 individuals in 1976.[2] It occurred in Philadelphia during the convention for the association of the U.S. veterans. “Clemsonensis” derives from “Clemson” where Clemson undergraduates were able to sequence this new strain.[3] Such as its other common strains: Legionella pneumophila, L. Feeleii, and L.sainthelensi, Legionella has a correlation with another genus called Coxiella. Both cause lung infection that can eventually led to pneumonia due to the intracellular bacteria in aerosols.[4]
Discovery
Based on physical characteristics, phylogenetic analysis, and membrane fatty acid composition, it was determined that the organism represented a unique lineage within the Legionella bacteria.The specific strain for Legionella clemsonensis is D5610.[5] It was named in honor of the research group of students from the Clemson’s Creative Inquiry.[1] Legionella clemsonensis was first isolated in 2006 from the bronchial wash of a patient diagnosed with pneumonia.[5] Bronchial washing is part of a bronchoscopy procedure.[5] After being isolated and stored, strain D5610 was acquired by The Center for Disease Control and Prevention (CDC).[1] CDC sent 68 strains of Legionella, including strain D5610 for students to analyze at Clemson University.[1] When isolated, it was shown to be very similar to bacteria genus Legionella. Researchers stated that "it was identified as Legionella based on sequencing, cellular fatty acid analysis, biochemical reactions, and biofilm characterization."[5] For a physical characterization of Legionella clemsonensis, it was streaked for a single colony isolation using a charcoal yeast extract agar and required cysteine for primary isolation.[5] No growth was shown, which was typical of Legionella strains. A characteristic that was found about Legionella clemsonensis is that it has a single, polar flagella.[5] Researchers also used fatty acid methyl ester analyses to distinguish differences between the Legionella strains.[5] Cellular fatty acid composition was analyzed using a Sherlock microbial Identification System.[6]
Preliminary characterization
Legionella clemsonensis was determined as a special lineage within the Legionella bacteria family based on its phylogenetic analysis and physical appearance. It is a Gram negative bacterium that is rod-shaped with one polar flagella to help them move around. The strain can grow between 26–45 °C forming biofilms that is similar to another strain of Legionella called L. pneumophila Philadelphia 1.[5] The strain D5610 of Legionella clemsonensis shows a distinctive temperature constraint compared to a lot of the Legionella species in the strain that does not grow under 26 °C and has a restriction of temperatures above 45 °C . Most Legionella strains have the ability to grow as high as 63 °C and very slowly at temperatures as low as 5 °C.[6] At both 37 °C and 26 °C, strain D5610 was found to grow more slowly than L. pneumophila Philadelphia 1 and it also formed a significant amount of pigment that was less produced.[6] These attributes suggest that this isolation is a standard Legionella species, for which the name Legionella clemsonensis was able to be produced. Legionella is considered to be pathogenic in humans and is one of the leading outbreaks correlated to constructed water systems. Because the biofilms are the source, countless outbreaks that originated from water systems and the ability of a species to form biofilms both can contribute to Legionella clemonensis’s pathogenicity.[7] The process of characterizing and sequencing the strain D5610 is still undergoing studying and investigating. Because this strain is still being investigated, there have been no findings of a specific metabolism for Legionella clemsonensis. Yet, Legionella’s usual metabolism is a facultative intracellular pathogen that increases in large numbers inside free-living amoebas, as well as macrophages and other protozoa.[8] In water systems, the pathogen lives in low metabolic state in the biofilms. A known strain of Legionella called in vitro L.pneumophila does not grow on standard medias like blood agar. This is because of the very low acidic conditions at a pH of 6.9 and certain amino acids such as cystein.[7] Yet even when these qualifications are met, the growth in the aerobic conditions are slow. This means that for there to be growth on the plate, it takes up to two to five days for colonies to be produced.[8] The genomics have yet to be stated for this particular strain of Legionella as well as the habitats. This is because this strain was discovered in 2016 and is still being examined.
Importance
Although this organism is fairly new, Legionella clemsonensis it is to be pathogenic. The Legionella species are commonly known to cause pneumonia. Currently, there is not a lot of information about these bacteria. Its metabolism process is still being investigated. A feature that sets Legionella clemsonensis apart was that under ultraviolet light, Legionella clemsonensis was fluorescent green.[5] This is different from other Legionella strains because they usually show up as fluorescent blue, red or yellow.[5]
References
- ^ a b c d "Bacteria strain named by Clemson students". Newsstand | Clemson University News and Stories, South Carolina. Retrieved 2017-04-24.
- ^ Altman, Lawrence K. (2006-08-01). "In Philadelphia 30 Years Ago, an Eruption of Illness and Fear". The New York Times. ISSN 0362-4331. Retrieved 2017-04-23.
- ^ "Clemson students name novel Legionella strain: Clemsonensis". Retrieved 2017-04-23.
- ^ Sauer, John Demian; Shannon, Jeffrey G.; Howe, Dale; Hayes, Stanley F.; Swanson, Michele S.; Heinzen, Robert A. (2005-08-01). "Specificity of Legionella pneumophila and Coxiella burnetii vacuoles and versatility of Legionella pneumophila revealed by coinfection". Infection and Immunity. 73 (8). doi:10.1128/IAI.73.8.4494-4504.2005. ISSN 0019-9567. PMC 1201193. PMID 16040960.
- ^ a b c d e f g h i j Palmer, Allison; Painter, Joseph; Hassler, Hayley; Richards, Vincent P.; Bruce, Terri; Morrison, Shatavia; Brown, Ellen; Kozak-Muiznieks, Natalia A.; Lucas, Claressa (2016-10-01). "Legionella clemsonensis sp. nov.: a green fluorescing Legionella strain from a patient with pneumonia". Microbiology and Immunology. 60 (10): 694–701. doi:10.1111/1348-0421.12439. ISSN 1348-0421.
- ^ a b c Declerck, Priscilla (2010-03-01). "Biofilms: the environmental playground of Legionella pneumophila". Environmental Microbiology. 12 (3): 557–566. doi:10.1111/j.1462-2920.2009.02025.x. ISSN 1462-2920. PMID 19678829.
- ^ a b Ashbolt, Nicholas J. (2015-06-19). "Environmental (Saprozoic) Pathogens of Engineered Water Systems: Understanding Their Ecology for Risk Assessment and Management". Pathogens. 4 (2): 390–405. doi:10.3390/pathogens4020390. PMC 4493481. PMID 26102291.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ a b Scheikl, Ute; Tsao, Han-Fei; Horn, Matthias; Indra, Alexander; Walochnik, Julia (2016-01-01). "Free-living amoebae and their associated bacteria in Austrian cooling towers: a 1-year routine screening". Parasitology Research. 115: 3365–3374. doi:10.1007/s00436-016-5097-z. ISSN 0932-0113. PMC 4980419. PMID 27177720.
