H37Rv

Last updated

Mycobacterium tuberculosis strain H37Rv is the most studied strain of tuberculosis in research laboratories. [1] It was first isolated by Dr. Edward R. Baldwin in 1905. [2] The strain came from a 19 year old patient with chronic pulmonary tuberculosis at the Trudeau Sanatorium in Saranac Lake, New York. [3] It was maintained for many years by serial passage of cultures at the Trudeau Sanatorium and initially named strain H37. Over time it was found to have variable virulence in animal models based on which medium it was grown on. Strains with different virulence were then intentionally produced, with H37R being less virulent after growing in acidic media and H37S was more virulent in guinea pigs after being grown in alkaline media (with R standing for resistant to environment, and S for sensitive to environment). [3] [4] The more virulent strain was later renamed H37Rv, with R standing for rough morphology and v standing for virulent. [4] The strain was used for many laboratory studies and became the standard for tuberculosis. It was later designated as the neotype for the species. [2] Koch first discovered mycobacterium tuberculosis as the cause of tuberculosis in 1892 but the strains he studied were not preserved and it is unclear how related H37Rv may be to those strains. H37Rv has continued to be the strain of tuberculosis most used in laboratories, and was the first to have its complete genome published in 1998. [5] It is unclear how much H37Rv may have evolved in more than 100 years under artificial conditions in laboratories from strains in the wild, but its genome is similar to a strain isolated from a 19th century grave in Yorkshire. [6] However it does not have some characteristics, such as causing caseous necrosis in rabbits, that are seen in modern clinical isolates. [7] Strains in different labs that derive from H37Rv have also been shown to have evolved differences over time, with one survey of 6 strains finding from 5 to 10 polymorphisms per strain. [8] These included independent insertions and deletions of IS6110 transposable elements which would change the strain's spoligotype. [8] The authors of the study cautioned against considering all strains labeled as H37Rv as a reference since there may be significant differences based on the laboratory in which it is maintained. [8]

Related Research Articles

BCG vaccine Vaccine primarily used against tuberculosis

Bacillus Calmette–Guérin (BCG) vaccine is a vaccine primarily used against tuberculosis (TB). It is named after its inventors Albert Calmette and Camille Guérin. In countries where tuberculosis or leprosy is common, one dose is recommended in healthy babies as soon after birth as possible. In areas where tuberculosis is not common, only children at high risk are typically immunized, while suspected cases of tuberculosis are individually tested for and treated. Adults who do not have tuberculosis and have not been previously immunized, but are frequently exposed, may be immunized, as well. BCG also has some effectiveness against Buruli ulcer infection and other nontuberculous mycobacterial infections. Additionally, it is sometimes used as part of the treatment of bladder cancer.

<i>Escherichia coli</i> Enteric, rod shaped, gram-negative bacterium

Escherichia coli, also known as E. coli, is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus Escherichia that is commonly found in the lower intestine of warm-blooded organisms. Most E. coli strains are harmless, but some serotypes (EPEC, ETEC etc.) can cause serious food poisoning in their hosts, and are occasionally responsible for food contamination incidents that prompt product recalls. The harmless strains are part of the normal microbiota of the gut, and can benefit their hosts by producing vitamin K2, and preventing colonisation of the intestine with pathogenic bacteria, having a mutualistic relationship. E. coli is expelled into the environment within faecal matter. The bacterium grows massively in fresh faecal matter under aerobic conditions for three days, but its numbers decline slowly afterwards.

<i>Mycobacterium tuberculosis</i> Species of pathogenic bacteria that causes tuberculosis

Mycobacterium tuberculosis is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis. First discovered in 1882 by Robert Koch, M. tuberculosis has an unusual, waxy coating on its cell surface primarily due to the presence of mycolic acid. This coating makes the cells impervious to Gram staining, and as a result, M. tuberculosis can appear weakly Gram-positive. Acid-fast stains such as Ziehl–Neelsen, or fluorescent stains such as auramine are used instead to identify M. tuberculosis with a microscope. The physiology of M. tuberculosis is highly aerobic and requires high levels of oxygen. Primarily a pathogen of the mammalian respiratory system, it infects the lungs. The most frequently used diagnostic methods for tuberculosis are the tuberculin skin test, acid-fast stain, culture, and polymerase chain reaction.

<i>Mycobacterium</i> Genus of bacteria

Mycobacterium is a genus of Actinomycetota, given its own family, the Mycobacteriaceae. Over 190 species are recognized in this genus. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis and leprosy in humans. The Greek prefix myco- means 'fungus', alluding to the way mycobacteria have been observed to grow in a mold-like fashion on the surface of cultures. It is acid-fast and cannot be stained by the Gram stain procedure.

<i>Mycobacterium leprae</i> Bacterium that causes leprosy

Mycobacterium leprae, is a bacterium that causes Hansen’s disease (leprosy), which is a chronic, curable infectious disease that damages the peripheral nerves and targets the skin, eyes, nose, and muscles. Leprosy can occur at all ages from infancy to old age. It was discovered in 1873 by the Norwegian physician Gerhard Armauer Hansen. It was the first bacterium to be identified as causing disease in humans.

<i>Mycobacterium smegmatis</i> Species of bacterium

Mycobacterium smegmatis is an acid-fast bacterial species in the phylum Actinomycetota and the genus Mycobacterium. It is 3.0 to 5.0 µm long with a bacillus shape and can be stained by Ziehl–Neelsen method and the auramine-rhodamine fluorescent method. It was first reported in November 1884 by Lustgarten, who found a bacillus with the staining appearance of tubercle bacilli in syphilitic chancres. Subsequent to this, Alvarez and Tavel found organisms similar to that described by Lustgarten also in normal genital secretions (smegma). This organism was later named M. smegmatis.

The Ames strain is one of 89 known strains of the anthrax bacterium. It was isolated from a diseased 14-month-old Beefmaster heifer that died in Sarita, Texas in 1981. The strain was isolated at the Texas Veterinary Medical Diagnostic Laboratory and a sample was sent to the United States Army Medical Research Institute of Infectious Diseases (USAMRIID). Researchers at USAMRIID mistakenly believed the strain came from Ames, Iowa because the return address on the package was the USDA's National Veterinary Services Laboratories in Ames and mislabeled the specimen.

Pyrazinamide Medication

Pyrazinamide is a medication used to treat tuberculosis. For active tuberculosis, it is often used with rifampicin, isoniazid, and either streptomycin or ethambutol. It is not generally recommended for the treatment of latent tuberculosis. It is taken by mouth.

<i>Mycobacterium marinum</i> Species of bacterium

Mycobacterium marinum is a slow growing mycobacterium (SGM) belonging to the genus Mycobacterium and the phylum Actinobacteria. The strain marinum was first identified by Aronson in 1926 and it is observed as a pathogenic mycobacterium. For example, tuberculosis like infections in fish (mycobacteriosis) and skin lesions in humans.

Lipoarabinomannan, also called LAM, is a glycolipid, and a virulence factor associated with Mycobacterium tuberculosis, the bacteria responsible for tuberculosis. Its primary function is to inactivate macrophages and scavenge oxidative radicals.

Mycobacterium microti

ESAT-6 or Early Secreted Antigenic Target 6 kDa, is produced by Mycobacterium tuberculosis, it is a secretory protein and potent T cell antigen. It is used in tuberculosis diagnosis by the whole blood interferon γ test QuantiFERON-TB Gold, in conjunction with CFP-10 and TB7.7.

CFP-10

CFP-10 within bacterial proteins is a protein that is encoded by the esxB gene.

Listeriolysin O (LLO) is a hemolysin produced by the bacterium Listeria monocytogenes, the pathogen responsible for causing listeriosis. The toxin may be considered a virulence factor, since it is crucial for the virulence of L. monocytogenes.

<i>Rhodococcus equi</i> Species of bacterium

Rhodococcus equi is a Gram-positive coccobacillus bacterium. The organism is commonly found in dry and dusty soil and can be important for diseases of domesticated animals. The frequency of infection can reach near 60%. R. equi is an important pathogen causing pneumonia in foals. Since 2008, R. equi has been known to infect wild boar and domestic pigs. R. equi can infect humans. At-risk groups are immunocompromised people, such as HIV-AIDS patients or transplant recipients. Rhodococcus infection in these patients resemble clinical and pathological signs of pulmonary tuberculosis. It is facultative intracellular.

Cord factor Chemical compound

Cord factor, or trehalose dimycolate, is a glycolipid molecule found in the cell wall of Mycobacterium tuberculosis and similar species. It is the primary lipid found on the exterior of M. tuberculosis cells. Cord factor influences the arrangement of M. tuberculosis cells into long and slender formations, giving its name. Cord factor is virulent towards mammalian cells and critical for survival of M. tuberculosis in hosts, but not outside of hosts. Cord factor has been observed to influence immune responses, induce the formation of granulomas, and inhibit tumor growth. The antimycobacterial drug SQ109 is thought to inhibit TDM production levels and in this way disrupts its cell wall assembly.

<i>Bacillus anthracis</i> Species of bacterium

Bacillus anthracis is a Gram-positive and rod-shaped bacterium that causes anthrax, a deadly disease to livestock and, occasionally, to humans. It is the only permanent (obligate) pathogen within the genus Bacillus. Its infection is a type of zoonosis, as it is transmitted from animals to humans. It was discovered by a German physician Robert Koch in 1876, and became the first bacterium to be experimentally shown as a pathogen. The discovery was also the first scientific evidence for the germ theory of diseases.

The Mycobacterium tuberculosis complex is a genetically related group of Mycobacterium species that can cause tuberculosis in humans or other animals.

Tuberculosinol synthase

Tuberculosinol synthase (EC 3.1.7.8, Rv3378c) is an enzyme with systematic name tuberculosinyl diphosphate diphosphohydrolase (tuberculosinol forming). This enzyme catalyses the following chemical reaction

Ashwani Kumar is an Indian bacteriologist, biotechnologies, and the principal scientist at the Institute of Microbial Technology (ImTech). He is known for his studies on Mycobacterium tuberculosis, the causative agent of tuberculosis. His laboratory focuses on understanding the reasons for drug tolerance observed in humans. His laboratory hypothesise that tuberculosis is a biofilm infection and that is why its treatment needs administration of multiple drugs for at least six months. The Department of Science and Technology has awarded him Swarnajayanti Fellowship for years 2016-2017.

References

  1. Camus, Jean-Christophe; Médigue, Claudine; Cole, Stewart T.; Pryor, Melinda J. (2002-10-01). "Re-annotation of the genome sequence of Mycobacterium tuberculosis H37Rv". Microbiology. 148 (10): 2967–2973. doi: 10.1099/00221287-148-10-2967 . PMID   12368430.
  2. 1 2 KUBICA, G. P.; KIM, T. H.; DUNBAR, F. P. (1972-04-01). "Designation of Strain H37Rv as the Neotype of Mycobacterium tuberculosis". International Journal of Systematic Bacteriology. 22 (2): 99–106. doi: 10.1099/00207713-22-2-99 .
  3. 1 2 Steenken, W.; Oatway, W. H.; Petroff, S. A. (1934-09-30). "Biological Studies of the Tubercle Bacillus: III. Dissociation and Pathogenicity of the R and S Variants of the Human Tubercle Bacillus (H37)". The Journal of Experimental Medicine. 60 (4): 515–540. doi:10.1084/jem.60.4.515. ISSN   0022-1007. PMC   2132400 . PMID   19870319.
  4. 1 2 Steenken, W. (1935). "Lysis of Tubercle Bacilli in Vitro". Experimental Biology and Medicine. 33 (2): 253–255. doi:10.3181/00379727-33-8330p. S2CID   87337106.
  5. Cole, S. T.; Brosch, R.; Parkhill, J.; Garnier, T.; Churcher, C.; Harris, D.; Gordon, S. V.; Eiglmeier, K.; Gas, S. (1998-06-11). "Deciphering the biology of Mycobacterium tuberculosis from the complete genome sequence". Nature. 393 (6685): 537–544. Bibcode:1998Natur.393..537C. doi: 10.1038/31159 . ISSN   0028-0836. PMID   9634230.
  6. Bouwman, Abigail S.; Kennedy, Sandra L.; Müller, Romy; Stephens, Richard H.; Holst, Malin; Caffell, Anwen C.; Roberts, Charlotte A.; Brown, Terence A. (2012-11-06). "Genotype of a historic strain of Mycobacterium tuberculosis". Proceedings of the National Academy of Sciences. 109 (45): 18511–18516. Bibcode:2012PNAS..10918511B. doi: 10.1073/pnas.1209444109 . ISSN   0027-8424. PMC   3494915 . PMID   23091009.
  7. Shammari, Basim Al; Shiomi, Takayuki; Tezera, Liku; Bielecka, Magdalena K.; Workman, Victoria; Sathyamoorthy, Tarangini; Mauri, Francesco; Jayasinghe, Suwan N.; Robertson, Brian D. (2015-08-01). "The Extracellular Matrix Regulates Granuloma Necrosis in Tuberculosis". Journal of Infectious Diseases. 212 (3): 463–473. doi:10.1093/infdis/jiv076. ISSN   0022-1899. PMC   4539912 . PMID   25676469.
  8. 1 2 3 Ioerger, Thomas R.; Feng, Yicheng; Ganesula, Krishna; Chen, Xiaohua; Dobos, Karen M.; Fortune, Sarah; Jacobs, William R.; Mizrahi, Valerie; Parish, Tanya (2010-07-15). "Variation among Genome Sequences of H37Rv Strains of Mycobacterium tuberculosis from Multiple Laboratories". Journal of Bacteriology. 192 (14): 3645–3653. doi:10.1128/JB.00166-10. ISSN   0021-9193. PMC   2897344 . PMID   20472797.