| Legionella |
Legionella sp. under UV illumination. | | Scientific classification | | | | Species | | Legionella adelaidensis
Legionella anisa
Legionella beliardensis
Legionella birminghamensis
Legionella bozemanii
Legionella brunensis
Legionella busanensis
Legionella cherrii
Legionella cincinnatiensis
Legionella donaldsonii
Legionella drancourtii
Legionella drozanskii
Legionella erythra
Legionella fairfieldensis
Legionella fallonii
Legionella feeleii
Legionella geestiana
Legionella gratiana
Legionella gresilensis
Legionella hackeliae
Legionella israelensis
Legionella jamestowniensis
Legionella jordanis
Legionella lansingensis
Legionella londiniensis
Legionella longbeachae
Legionella lytica
Legionella maceachernii
Legionella micdadei
Legionella monrovica
Legionella nautarum
Legionella oakridgensis
Legionella parisiensis
Legionella pneumophila
Legionella quateirensis
Legionella quinlivanii
Legionella rowbothamii
Legionella rubrilucens
Legionella sainthelensi
Legionella santicrucis
Legionella shakespearei
Legionella spiritensis
Legionella steigerwaltii
Legionella taurinensis
Legionella tucsonensis
Legionella wadsworthii
Legionella waltersii
Legionella worsleiensis Image File history File links Download high resolution version (700x694, 461 KB)Legionella sp. ...
For other uses, see Scientific classification (disambiguation). ...
Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ...
Orders Alpha Proteobacteria Caulobacterales - e. ...
Orders Alpha Proteobacteria Caulobacterales - e. ...
Families & Genera Legionellaceae Fluoribacter Legionella Sarcobium Tatlockia Coxiellaceae Coxiella Rickettsiella The Legionellales are an order of proteobacteria. ...
Families & Genera Legionellaceae Fluoribacter Legionella Sarcobium Tatlockia Coxiellaceae Coxiella Rickettsiella The Legionellales are an order of proteobacteria. ...
Legionella Longbeachae is one species of the Legionellaceae family. ...
Legionellosis is an infection caused by species of the bacterium Legionella, most notably . ...
| Legionella is a Gram negative bacterium, including species that cause legionellosis or Legionnaires' disease, most notably L. pneumophilia.[1] Legionella are common in many environments, with at least 48 species and 70 serogroups identified. The side-chains of the cell wall carry the bases responsible for the somatic antigen specifity of these organisms. The chemical composition of these side chains both with respect to components as well as arrangement of the different sugars determines the nature of the somatic or O antigen determinants, which are essential means of serologically classifying many Gram-negative bacteria. Gram-negative bacteria are those that do not retain crystal violet dye in the Gram staining protocol. ...
Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ...
Legionellosis is an infection caused by the genus of Gram negative bacteria Legionella, notably Legionella pneumophila. ...
Legionellosis is an infection caused by species of the bacterium Legionella, most notably . ...
In biology, a species is one of the basic units of biodiversity. ...
This page is a candidate to be copied to Wiktionary using the Transwiki process. ...
A side chain in organic chemistry and biochemistry which is a part of a molecule that is attached to a core structure. ...
A cell wall is a fairly rigid layer surrounding a cell located outside of the plasma membrane (also known, in some cases, as the cell membrane) that provides additional support and protection. ...
Pathogenesis
Legionella have been known for some time to live within amoebae in the natural environment.[2] Legionella species are the causative agent of the human Legionnaires' disease and the lesser form, Pontiac fever. Legionella transmission is via aerosols—the inhalation of mist droplets containing the bacteria. Common sources include cooling towers, domestic hot-water systems, fountains, and similar disseminators that tap into a public water supply. Natural sources of Legionella include freshwater ponds and creeks. Person-to-person transmission of Legionella has not been demonstrated.[3] Image 1: Natural draft wet cooling towers at Didcot Power Station, UK Cooling towers are evaporative coolers used for cooling water or other working medium to near the ambient wet-bulb air temperature. ...
Once inside a host, incubation may take up to two weeks. Initial symptoms are flu-like, including fever, chills, and dry cough. Advanced stages of the disease cause problems with the gastrointestinal tract and the nervous system and lead to diarrhea and nausea. Other advanced symptoms of pneumonia may also present. For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and...
However, the disease is generally not a threat to most healthy individuals, and tends to lead to harmful symptoms only in those with a compromised immune system and the elderly. Consequently, it is actively checked for in the water systems of hospitals and nursing homes. In the United States, the disease affects between 8,000 to 18,000 individuals a year.
Controlling potential sources of Legionella Common sources of Legionella include cooling towers used in industrial cooling water systems as well as in large central air conditioning systems, domestic hot water systems, fountains, and similar disseminators that draw upon a public water supply. Natural sources include freshwater ponds and creeks. Cooling towers are structures for cooling water or other working medium to near-ambient temperature. ...
Central air conditioning, commonly referred to as central air, is an air conditioning system which uses ducts to distribute cooled and/or dehumidified air to more than one room, or uses pipes to distribute chilled water to heat exchangers in more than one room, and which is not plugged into...
Recent research in the Journal of Infectious Diseases provides evidence that Legionella pneumophila, the causative agent of Legionnaires disease, can travel at least 6 km from its source by airborne spread. It was previously believed that transmission of the bacterium was restricted to much shorter distances. A team of French scientists reviewed the details of an epidemic of Legionnaires disease that took place in Pas-de-Calais in northern France in 2003–2004. There were 86 confirmed cases during the outbreak, of whom 18 perished. The source of infection was identified as a cooling tower in a petrochemical plant, and an analysis of those affected in the outbreak revealed that some infected people lived as far as 6–7 km from the plant.[4] Petrochemicals are chemical products made from raw materials of petroleum (hydrocarbon) origin. ...
Several European countries established a working group known as the European Working Group for Legionella Infections (EWGLI)[5] to share knowledge and experience about monitoring potential sources of Legionella. That group has published guidelines about the actions to be taken to limit the number of colony forming units (i.e., the aerobic count) of micro-organisms per mL at 30°C (minimum 48 hours incubation):
| Aerobic count | Action required | | 10,000 or less | System under control. | more than 10,000
up to 100,000 | Review program operation. The count should be confirmed by immediate re-sampling. If a similar count is found again, a review of the control measures and risk assessment should be carried out to identify any remedial actions. | | more than 100,000 | Implement corrective action. The system should immediately be re-sampled. It should then be ‘shot dosed’ with an appropriate biocide, as a precaution. The risk assessment and control measures should be reviewed to identify remedial actions. | Temperature affects the survival of Legionellae as follows: - 70 to 80 °C (158 to 176 °F) - Disinfection range
- At 66 °C (151 °F) - Legionellae die within 2 minutes
- At 60 °C (140 °F) - Legionellae die within 32 minutes
- At 55 °C (131 °F) - Legionellae die within 5 to 6 hours
- 50 to 55 °C (122 to 131 °F) - They can survive but do not multiply
- 20 to 50 °C (68 to 122 °F)- Legionellae growth range
- 35 to 46 °C (95 to 115 °F) - Ideal growth range
- Below 20 °C (68 °F) - Legionellae can survive but are dormant
The above data can be confirmed in an online article by Reliance World Wide.[6]
Control of Legionella growth can be through :
A. Chemical Treatment 1. Short term - Cl2, must be repeated every 3 to 5 weeks, corrotion factors 2. Long term - ClO2, takes up to 17 months for system saturation B. Non-Chemical Treatment 1. Short term - Thermal eradication - must be repeated every 3 to 5 weeks 2. Long term - Industrial size copper silver ionisation (Ionization) technology such as AquaLyseusa.com
Guidelines for control of Legionella in cooling towers Many governmental agencies, cooling tower manufacturers and industrial trade organizations have developed design and maintenance guidelines for preventing or controlling the growth of Legionella in cooling towers. Below is a list of sources for such guidelines:
References - ^ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th Edition, McGraw Hill. ISBN 0-8385-8529-9.
- ^ Swanson M, Hammer B (2000). "Legionella pneumophila pathogesesis: a fateful journey from amoebae to macrophages". Annu Rev Microbiol 54: 567-613. PMID 11018138.
- ^ Winn, W.C. Jr. (1996). Legionella (In: Baron's Medical Microbiology, Baron, S. et al, eds., 4th Edition, University of Texas Medical Branch. ISBN 0-9631172-1-1. (via NCBI Bookshelf)
- ^ Nguyen T, Ilef D, Jarraud S, Rouil L, Campese C, Che D, Haeghebaert S, Ganiayre F, Marcel F, Etienne J, Desenclos J (2006). "A community-wide outbreak of legionnaires disease linked to industrial cooling towers--how far can contaminated aerosols spread?". J Infect Dis 193 (1): 102-11. PMID 16323138.
- ^ European Working Group for Legionella Infections
- ^ What is Legionnaires' Disease?
See also Legionellosis is an infection caused by species of the bacterium Legionella, most notably . ...
A biocide is a chemical substance capable of killing different forms of living organisms used in fields such as medicine, agriculture, forestry, and mosquito control. ...
External links - Images of Legionella bacteria:
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