Mycobacterium abscessus: Difference between revisions
Rim Halaby (talk | contribs) |
Rim Halaby (talk | contribs) |
||
| Line 54: | Line 54: | ||
==Risk Factors== | ==Risk Factors== | ||
* Open wounds | |||
* Injections without appropriate skin disinfection | |||
*Chronic lung disease | * Immune suppression | ||
* Chronic lung disease (for example, [[cystic fibrosis) | |||
*Post-tympanostomy tube [[otitis media]] | * Post-tympanostomy tube [[otitis media]] | ||
==Diagnosis== | ==Diagnosis== | ||
Revision as of 01:04, 23 July 2014
| Mycobacterium abscessus | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Scientific classification | ||||||||||||||
| ||||||||||||||
| Binomial name | ||||||||||||||
| Mycobacterium abscessus Kusonoki and Ezaki 1992 ATCC 19977 |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords: M. abcessus
Overview
Mycobacterium abscessus is a rapidly growing mycobacterium that is a common water contaminant. It was until recently (1992) thought to be a subspecies of Mycobacterium chelonae. M. abcessus can cause infections in patients with chronic lung disease such as cystic fibrosis, post-traumatic wound infections, and disseminated cutaneous diseases, mostly in patients with suppressed immune systems. Mycobacterium abscessus is a bacterium distantly related to the ones that cause tuberculosis and leprosy. It is part of a group known as rapidly growing mycobacteria and is found in water, soil, and dust. It has been known to contaminate medications and products, including medical devices.
Historical Perspective
Mycobacterium abscessus was first isolated from gluteal abscesses in a 62-year-old patient who had injured her knee as a child and had a disseminated infection 48 years later. The species M. bolletii, named after the late microbiologist and taxonomist Claude Bollet, was described in 2006. In current taxonomy, M. bolletii and M. massiliense (named for Massilia, the ancient Greek and Roman name for Marseille, where the organism was isolated) have been incorporated into M. abscessus subsp. bolletii. [1]
Pathophysiology
Transmission
Infection with M. abscessus is usually caused by injections of substances contaminated with the bacterium or through invasive medical procedures employing contaminated equipment or material. Infection can also occur after accidental injury where the wound is contaminated by soil. There is very little risk of transmission from person to person.
Microscopy
- Gram-positive, nonmotile and acid-fast rods (1.0-2.5µm x 0.5µm).
Colony characteristics
- Colonies on Löwenstein-Jensen media may occur as smooth as well as rough, white or greyish and nonphotochromogenic.
Physiology
- Growth at 28°C and 37°C after 7 days but not at 43°C.
- On MacConkey agar at 28°C and even 37°C.
- Tolerance to 5% NaCl and 500mg/l hydroxylamine (Ogawa egg medium) and 0.2% picrate (Sauton agar medium).
- Positive degradation of p-aminosalicylate.
- Production of arylsulfatase but not of nitrate reductase and Tween 80 hydrolase.
- Negative iron uptake test. No utilisation of fructose, glucose, oxalate and citrate as sole carbon sources.
Differential characteristics
- M. abscessus and M. chelonae can be distinguished from M. fortuitum or M. peregrinum by their failure to reduce nitrate and to take up iron.
- Tolerance to 5% NaCl in Löwenstein-Jensen media tolerance to 0.2% picrate in Sauton agar and non-utilisation of citrate as a sole carbon source are characteristics that distinguish M. abscessus from M. chelonae.
- M. abscessus and M. chelonae sequevar I share an identical sequence in the 54-510 region of 16S rRNA, However, both species can be differentiated by their hsp65 or ITS sequences
Strains
ATCC 19977 = CCUG 20993 = CIP 104536 = DSM 44196 = JCM 13569 = NCTC 13031
Genetics
A draft genome sequence of M. abscessus subsp. bolletii BDT was completed in 2012.[2] More than 25 different strains of this subspecies, including pathogenic isolates, have had their genomes sequenced.[3]
Risk Factors
- Open wounds
- Injections without appropriate skin disinfection
- Immune suppression
- Chronic lung disease (for example, [[cystic fibrosis)
- Post-tympanostomy tube otitis media
Diagnosis
History
The patient should be asked about a recent history of received procedures, such as surgery or injections.
Symptoms
- Red, warm, tender to the touch, swollen, and/or painful skin
- Boils
- Pus-filled vesicles
- Fever
- Chills
- Muscle aches
- Malaise
Physical Examination
Skin
- Skin infected with M. abscessus is usually red, warm, tender to the touch, swollen, and/or painful.
- Infected areas can also develop boils or pus-filled vesicles.
Laboratory Studies
To reach a definitive diagnosis, the organism has to be cultured from the infection site or, in severe cases, from a blood culture. The diagnosis is made by growing this bacterium in the laboratory from a sample of the pus or biopsy of the infected area.
Treatment
Medical Therapy
The recommended treatment strategy is to combine three drugs
2. Amikacin or another aminoglycoside
3. An injectable agent such as either cefoxitin or imipenem
Surgical Treatment
Treatment of infections due to M. abscessus consists of draining collections of pus or removing the infected tissue and administering the appropriate combination of antibiotics for a prolonged period of time. Infection with this bacterium usually does not improve with the usual antibiotics used to treat skin infections. Testing the bacteria against different antibiotics is helpful in guiding doctors to the most appropriate treatment for each patient.
Primary Prevention
- Anyone who touches or cares for the infected site should wash their hands carefully with soap and water.
- Patients should follow all instructions given by their healthcare provider following any surgery or medical procedure.
- Avoid receiving procedures or injections by unlicensed persons.
Source
Publicly available content from the United States CDC
References
- ↑ Etymologia: Mycobacterium abscessus subsp. bolletii. Emerg Infect Dis [Internet]. 2014 Mar [February 20, 2014]. http://dx.doi.org/10.3201/eid2003.ET2003
- ↑ Choi, G.-E.; Cho, Y.-J.; Koh, W.-J.; Chun, J.; Cho, S.-N.; Shin, S. J. (24 April 2012). "Draft Genome Sequence of Mycobacterium abscessus subsp. bolletii BDT". Journal of Bacteriology. 194 (10): 2756–2757. doi:10.1128/JB.00354-12.
- ↑ Davidson, Rebecca M. (December 2013). "Phylogenomics of Brazilian epidemic isolates of Mycobacterium abscessus subsp. bolletii reveals relationships of global outbreak strains". Infection, Genetics and Evolution. 20: 292–297. doi:10.1016/j.meegid.2013.09.012. Unknown parameter
|coauthors=ignored (help)
- Kusunoki,S.,T. Ezaki. 1992. Proposal of Mycobacterium peregrinum sp. nov., nom. rev., and elevation of Mycobacterium chelonae subsp. abscessus (Kubica et al.) to species status: Mycobacterium abscessus comb. nov. Int. J. Syst. Bacteriol. 42, 240-245.