Mycobacterium shottsii is a slowly growing, non-pigmented mycobacteria isolated from striped bass (Morone saxatilis) during an epizootic

Epizootic

In epizoology, an epizootic is a disease that appears as new cases in a given animal population, during a given period, at a rate that substantially exceeds what is "expected" based on recent experience . Epidemic is the analogous term applied to human populations...

 of mycobacteriosis in the Chesapeake Bay

Chesapeake Bay

The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's drainage basin covers in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West...

. Growth characteristics, acid-fastness and results of 16S rRNA gene sequencing were consistent with those of the genus Mycobacterium

Mycobacterium

Mycobacterium is a genus of Actinobacteria, given its own family, the Mycobacteriaceae. The genus includes pathogens known to cause serious diseases in mammals, including tuberculosis and leprosy...

. A unique profile of biochemical reactions was observed among the 21 isolates. A single cluster of eight peaks identified by analysis of mycolic acid

Mycolic acid

Mycolic acids are long fatty acids found in the cell walls of the mycolata taxon, a group of bacteria that includes Mycobacterium tuberculosis, the causative agent of the disease tuberculosis. They form the major component of the cell wall of mycolata species...

s (HPLC) resembled those of reference patterns but differed in peak elution times from profiles of reference species of the Mycobacterium tuberculosis

Mycobacterium tuberculosis

Mycobacterium tuberculosis is a pathogenic bacterial species in the genus Mycobacterium and the causative agent of most cases of tuberculosis . First discovered in 1882 by Robert Koch, M...

complex. Etymology

Etymology

Etymology is the study of the history of words, their origins, and how their form and meaning have changed over time.For languages with a long written history, etymologists make use of texts in these languages and texts about the languages to gather knowledge about how words were used during...

: shottsii; of Shotts, named after Emmett Shotts, an American fish bacteriologist.

Description

Microscopy

• Gram positive, acid-fast coccobacilli that may form cell aggregates in culture. Spores and cell branching are not present.

Colony characteristics

• Colonies on Middlebrook 7H10 agar are dysgonic, rough, non-pigmented and typically flat with an irregular margin, becoming umbonate upon ageing.
• Smooth colonies with an entire margin are seen less frequently.

Physiology

• Visible colonies from a dilute inoculum are observed after 4–6 weeks incubation at 23°C.
• Little or no growth occurs at 30°C and none at 37°C or above.
• Isolates do not grow on MacConkey agar or with 5% NaCl, are negative for arylsulfatase (14 days), b-galactosidase, nitrate reductase, pyrazinamidase (7 days), semiquantitative catalase, Tween 80 hydrolysis and Tween opacity and have variable reactions for acid phosphatase and catalase at 68°C.
• The type strain is resistant to p-aminosalicylic acid and isoniazid but susceptible to ethambutol, ethionamide, kanamycin, rifampicin and streptomycin in disc susceptibility tests.

Differential characteristics

• The 16S rRNA gene sequence is unique among species of Mycobacterium and is most similar to those of Mycobacterium ulcerans
  Mycobacterium ulcerans
  Mycobacterium ulcerans is a slow-growing mycobacterium that classically infects the skin and subcutaneous tissues, giving rise to indolent nonulcerated and ulcerated lesions. After tuberculosis and leprosy, Buruli ulcer is the third most common mycobacteriosis of humans. M...
  
   and Mycobacterium marinum
  Mycobacterium marinum
  Mycobacterium marinum is a free-living bacterium, which causes opportunistic infections in humans.- History :Although Aronson isolated this mycobacterium in 1926 from a fish, it was not until 1951 that it was found to be the cause of human disease by Linell and Norden...
  
  .
• Isolate M175T could be differentiated from other slowly growing, non-pigmented mycobacteria by its inability to grow at 37 °C, production of niacin
  Niacin
  "Niacin" redirects here. For the neo-fusion band, see Niacin .Niacin is an organic compound with the formula and, depending on the definition used, one of the forty to eighty essential human nutrients.Niacin is one of five vitamins associated with a pandemic deficiency disease: niacin deficiency...
  
   and urease
  Urease
  Urease is an enzyme that catalyzes the hydrolysis of urea into carbon dioxide and ammonia. The reaction occurs as follows:In 1926, James Sumner showed that urease is a protein. Urease is found in bacteria, yeast, and several higher plants. The structure of urease was first solved by P.A...
  
  , absence of nitrate reductase
  Nitrate reductase
  Nitrate reductases are molybdoenzymes that reduce nitrate to nitrite .* Eukaryotic nitrate reductases are part of the sulfite oxidase family of molybdoenzymes....
  
   and resistance to isoniazid
  Isoniazid
  Isoniazid , also known as isonicotinylhydrazine , is an organic compound that is the first-line antituberculosis medication in prevention and treatment. It was first discovered in 1912, and later in 1951 it was found to be effective against tuberculosis by inhibiting its mycolic acid...
  
  , thiacetazone and thiophene-2-carboxylic hydrazide.

Type strain

• First isolated from granulomatous lesions in splenic tissue from a striped bass (Morone saxatilis).
• Strain M175 = ATCC 700981 = JCM 12657 = NCTC 13215