PUBLICATION

Biochemical, molecular, and virulence characteristics of select Mycobacterium marinum isolates in hybrid striped bass Morone chrysops x M. saxatilis and zebrafish Danio rerio

Authors
Ostland, V.E., Watral, V., Whipps, C.M., Austin, F.W., St-Hilaire, S., Westerman, M.E., and Kent, M.L.
ID
ZDB-PUB-080527-22
Date
2008
Source
Diseases of aquatic organisms   79(2): 107-118 (Journal)
Registered Authors
Kent, Michael, Westerman, Mark E.
Keywords
Mycobacterium marinum, Hybrid striped bass, Zebrafish, Mycobacteriosis, Virulence
MeSH Terms
  • Animals
  • Bass/microbiology*
  • Crosses, Genetic
  • DNA, Ribosomal Spacer/genetics
  • Fish Diseases/microbiology*
  • Fish Diseases/mortality
  • Fish Diseases/pathology
  • Heat-Shock Proteins/genetics
  • Hybridization, Genetic
  • Mycobacterium Infections, Nontuberculous/microbiology
  • Mycobacterium Infections, Nontuberculous/mortality
  • Mycobacterium Infections, Nontuberculous/pathology
  • Mycobacterium Infections, Nontuberculous/veterinary*
  • Mycobacterium marinum/genetics
  • Mycobacterium marinum/isolation & purification*
  • Mycobacterium marinum/pathogenicity*
  • Spleen/microbiology
  • Virulence/genetics
  • Zebrafish/microbiology*
PubMed
18500027 Full text @ Dis. Aquat. Organ.
Abstract
A panel of 15 Mycobacterium marinum isolates was characterized by biochemical tests, sequencing the ribosomal DNA intergenic spacer (ITS) region and the heat shock protein 65 gene (hsp65) and pulsed-field gel electrophoresis (PFGE). The biochemical characteristics of all isolates were similar, except for Tween 80 hydrolysis. DNA sequence of hsp65 for a subset of isolates were identical; however, at position 5 of the ITS rDNA, a single nucleotide polymorphism was identified. Isolates possessing a guanine residue at this position (G strains) were unable to hydrolyze Tween 80, while isolates that contained an adenine residue at this position (A strains) were positive for Tween 80 hydrolysis. PFGE successfully discriminated between the G and A strains; all G strains had identical AseI restriction enzyme-cutting patterns while the A strains exhibited a variety of cutting patterns. Eight isolates (4 G and 4 A strains) were further characterized for virulence by experimental infection of hybrid striped bass (HSB) Morone chrysops x M. saxatilis and zebrafish Danio rerio. Seven of the 8 strains produced cumulative mortality ranging from 13.3 to 83.3% in the HSB virulence trial. The M. marinum reference strain ATCC 927T did not produce mortality in HSB. HSB exposed to the G strains had significantly higher cumulative mortality than those exposed to the A strains. When these same isolates were tested in zebrafish, 6 of the 8 strains caused 100% cumulative mortality, with 2 of the A strains being the most pathogenic. In zebrafish, however, ATCC 927T was virulent and produced 28.5% mortality. Collectively, we conclude that the M. marinum G strains are unique and may represent a distinct virulence phenotype in HSB, but this trend was not consistent in zebrafish.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping