Mycobacterium avium subspecies paratuberculosis

Pictures

Picture	Title	Caption	Copyright
Title Stained section of ileum Caption Acid-fast stain of M. avium ss paratuberculosis in a cross-section of ileum from a clinically infected sheep. Copyright Judith R. Stabel/USDA-ARS-National Animal Disease Center	Stained section of ileum	Acid-fast stain of M. avium ss paratuberculosis in a cross-section of ileum from a clinically infected sheep.	Judith R. Stabel/USDA-ARS-National Animal Disease Center

Identity

Preferred Scientific Name

• Mycobacterium avium subspecies paratuberculosis

Other Scientific Names

• Mycobacterium avium subsp. paratuberculosis
• Mycobacterium chronicae pseudotuberculosae bovis

International Common Names

• English: Mycobacterium paratuberculosis

Taxonomic Tree

• Domain: Bacteria
•     Phylum: Actinobacteria [phylum]
•         Class: Actinobacteria
•             Subclass: Actinobacteridae
•                 Order: Actinomycetales
•                     Suborder: Corynebacterineae
•                         Family: Mycobacteriaceae
•                             Genus: Mycobacterium
•                                 Species: Mycobacterium avium subspecies paratuberculosis

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Pathogen Characteristics

Mycobacterium avium subspecies paratuberculosis causes paratuberculosis (Johne's disease) in cattle and other ruminants.

M. avium ss paratuberculosis is a small (0.5 µm ´ 1.5 µm), facultative, acid-fast bacterium. The bacteria grow in clumps due to the complex cell wall formed by peptidoglycolipids (Merkal et al., 1973; Brennan and Nikaido, 1995). On agar medium, M. avium ss paratuberculosis grows as small, opaque colonies with a mixture of smooth and rough morphologies. Primary isolation and propagation of M. avium ss paratuberculosisin vitro requires mycobactin, an iron-chelating agent produced by most species of mycobacteria. Although M. avium ss paratuberculosis is capable of scavenging iron in vivo, it is dependent upon the addition of exogenous mycobactin or other iron sources to synthetic medium in order to grow in vitro (Lambrecht and Collins, 1992). Primary culture of M. avium ss paratuberculosis from tissue or faecal samples takes 12-16 weeks on agar medium such as Herrold's egg yolk or Lowenstein-Jensen medium, although recovery rates are shorter for heavily infected tissues. More recently, primary isolation of M. avium ss paratuberculosis using liquid medium formulations has improved the rates of recovery (Cousins et al., 1995; Whittington et al., 1998). Biochemical characteristics of M. avium ss paratuberculosis may vary between strains, although there is evidence to suggest that the neutral red test may be used to determine virulence of M. avium ss paratuberculosis strains, and that catalase activity may be useful to discriminate between M. avium ss paratuberculosis and other species of mycobacteria (Merkal and Thurston, 1966).

Disease(s) associated with this pathogen is/are on the list of diseases notifiable to the World Organisation for Animal Health (OIE). The distribution section contains data from OIE's Handistatus database on disease occurrence. Please see the AHPC library for further information from OIE, including the International Animal Health Code and the Manual of Standards for Diagnostic Tests and Vaccines. Also see the website: www.oie.int.

References

Brennan PJ; Nikaido H, 1995. The envelope of mycobacteria. Ann. Rev. Biochem., 64:29-63.

Cousins DV; Evans RJ; Francis BR, 1995. Use of BACTEC radiometric culture method and polymerase chain reaction for the rapid screening of faeces and tissues for Mycobacterium paratuberculosis. Australian Veterinary Journal, 72(12):458-462; 13 ref.

Lambrecht RS; Collins MT, 1992. Mycobacterium paratuberculosis. Factors that influence mycobactin dependence. Diagn. Microbiol. Infect. Dis., 15(3):239-246.

Merkal RS; Rhoades KR; Gallagher JE; Ritchie AE, 1973. Scanning electron microscopy of mycobacteria. Ann. Rev. Resp. Dis., 108:382-387.

Merkal RS; Thurston JR, 1966. Comparison of Mycobacterium paratuberculosis and other mycobacteria, using standard cytochemical tests. Am. J. Vet. Res., 27(117):519-521.

OIE Handistatus, 2002. World Animal Health Publication and Handistatus II (dataset for 2001). Paris, France: Office International des Epizooties.

OIE Handistatus, 2003. World Animal Health Publication and Handistatus II (dataset for 2002). Paris, France: Office International des Epizooties.

OIE Handistatus, 2004. World Animal Health Publication and Handistatus II (data set for 2003). Paris, France: Office International des Epizooties.

OIE Handistatus, 2005. World Animal Health Publication and Handistatus II (data set for 2004). Paris, France: Office International des Epizooties.

Whittington RJ et al., 1998. Rapid detection of Mycobacterium paratuberculosis in clinical samples from ruminants and in spiked environmental samples by modified BACTEC 12B radiometric culture and direct confirmation by IS900 PCR. J. Clin. Microbiol., 36(3):701-707.

Distribution Maps