Klebsiella pneumoniae
| Klebsiella pneumoniae | |
|---|---|
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| K. pneumoniae on a MacConkey agar plate. | |
| Scientific classification | |
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| Phylum: | |
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| Species: | K. pneumoniae
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| Binomial name | |
| Klebsiella pneumoniae (Schroeter 1886)
Trevisan 1887 | |
Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose fermenting, facultative anaerobic, rod shaped bacterium found in the normal flora of the mouth, skin, and intestines.[1] It is clinically the most important member of the Klebsiella genus of Enterobacteriaceae; it is closely related to K. oxytoca from which it is distinguished by being indole-negative and by its ability to grow on both melezitose and 3-hydroxybutyrate. It naturally occurs in the soil, and about 30% of strains can fix nitrogen in anaerobic condition.[2] As a free-living diazotroph, its nitrogen fixation system has been much studied.
Members of the Klebsiella genus typically express 2 types of antigens on their cell surface. The first, O antigen, is a component of the lipopolysaccharide (LPS), of which 9 varieties exist. The second is K antigen, a capsular polysaccharide with more than 80 varieties.[3] Both contribute to pathogenicity and form the basis for serogrouping.
History
The Danish scientist Hans Christian Gram (1853-1938), developed the technique now known as Gram staining in 1884 to discriminate between K. pneumoniae and Streptococcus pneumoniae.
Klebsiella was named after the German bacteriologist Edwin Klebs (1834-1913).
Multiply-resistant Klebsiella pneumoniae have been killed in vivo via intraperitoneal, intravenous or intranasal administration of phages in laboratory tests.[4]
Clinical significance
K. pneumoniae can cause the disease Klebsiella pneumonia.
Research conducted at King's College, London has implicated molecular mimicry between HLA-B27 and two Klebsiella surface moleculars as the cause of ankylosing spondylitis.[5] As a general rule, Klebsiella infections tend to occur in people with a weakened immune system from improper diet (alcoholics and diabetics). Many of these infections are obtained when a person is in the hospital for some other reason (a nosocomial infection). The most common infection caused by Klebsiella bacteria outside the hospital is pneumonia.
New antibiotic resistant strains of K. pneumoniae are appearing, and it is increasingly found as a nosocomial infection.[6]
Klebsiella ranks second to E. coli for urinary tract infections in older persons. It is also an opportunistic pathogen for patients with chronic pulmonary disease, enteric pathogenicity, nasal mucosa atrophy, and rhinoscleroma. Feces are the most significant source of patient infection, followed by contact with contaminated instruments.
See also
References
- ^ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. ISBN 0838585299.
{{cite book}}:|author=has generic name (help)CS1 maint: multiple names: authors list (link) - ^ Postgate J (1998). Nitrogen fixation, 3rd ed. Cambridge University Press.
- ^ Podschun R, Ullman U (1998). "Klebsiella spp. as Nosocomial Pathogens: Epidemiology, Taxonomy, Typing Methods, and Pathogenicity Factors". Clinical Microbiology Reviews. 11 (4): 589–603. PMC 88898. PMID 9767057.
- ^ [1]
- ^ Rashid T, Ebringer A (2006). "Ankylosing spondylitis is linked to Klebsiella-the evidence (Epub ahead of print)". Clin Rheumatol. 26 (6): 858–64. doi:10.1007/s10067-006-0488-7. PMID 17186116.
- ^ [2]
External links
- Diseases, symptoms, diagnosis of K. pneumoniae (University of Florida) (Page is missing now)
- Virtual museum of bacteria page on K. pneumoniae
- What're the complications of pneumonia? (health-cares.net)
- Klebsiella Infection (emedicine.com)
- Klebsiella Genome Projects from Genomes OnLine Database
- Klebsiella pneumoniae-Associated Vertebral Osteomyelitis After Laparoscopic Cholecystectomy