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Mycobacterium avium subspecies paratuberculosis Biological Agent Reference Sheet (BARS)

Updated November 29th, 2023

Disclaimer: Risk group, biosafety level, and all other precautions noted here are subject to change after a risk assessment by EHS.


Agent Type Risk Group Biosafety Level Animal Housing Biosafety Level
Bacteria  RG-2 BSL-2 ABSL-2

Agent Characteristics 

Risk Group: RG-2 associated with human disease, rarely serious; preventive or therapeutic interventions often available.

Agent Type: Bacteria 

DescriptionMycobacterium avium subspecies paratuberculosis, often abbreviated M. paratuberculosis, M. avium ssp. paratuberculosis, or MAP, is a gram-positive facultative intracellular pathogen. It is the causative agent of Johne's ("Yo-knee's") disease, a chronic disease of the intestines that affects ruminants such as cattle. In humans, MAP may play a role in the development of Crohn's disease. The type strain is ATCC 19698 (equivalent to CIP 103963 or DSM 44133) (Thorel 1990).

Host Range: MAP is found primarily in ruminants (cattle, sheep, goats, deer, antelope, bison, etc.) and their threechambered stomach relatives (Chacon 2004). MAP has also been found to infect a variety of other wild animals, such as badger, fox, primates, rabbits, and swine (Collins 2003b).

Host Shedding: Blood, Feces, Milk, Colostrum           

Route of Exposure to Humans: Aerosol/Inhalation, Ingestion, Percutaneous

Infectious Dose: Unknown                                     Incubation Period: Symptoms usually appear within 1-10 years. 

Health Hazards

Signs and symptoms of infection may include:

  • Flu-like symptoms (i.e. fever, headache, dehydration, weight loss, lethargy)
  • Gastrointestinal symptoms (i.e. loss of appetite, nausea, vomiting, diarrhea)
  • Lymphoreticular symptoms (i.e. enlarged internal organs or lymph nodes)

Immunizations: None available                                 Prophylaxis*: None available

*Formal medical advice is obtained during medical consultations with Cornell Health or primary healthcare provider as needed.

Agent Viability 

Survival Outside Host Disinfection

Soil: up to 117 weeks, 55 weeks in fully enclosed, dry environment

Water: up to 41 months

Laboratory: desiccated culture at 38°C >48 months; frozen bovine feces stored at -70°C >15 weeks

Mycobactericidal containing acetic acid, peracetic acid, and hydrogen peroxide such as NuCidex or Accel TB

If animal feces need to be cleaned up, a phenol-based cleaner with a surfactant, such as Amphyl is recommended

Bleach and Virkon-S have minimal effectiveness against MAP

For more guidance on disinfection see:  disinfectant selection.

Laboratory Hazards 

  • High energy-creating activities (centrifugation, sonication, high pressure systems, vortexing, tube cap popping)
  •  Handling of sharps (needles, scalpels, microtome blades, broken glass, etc.)
  •  Splash/droplet-creating activities (shaking incubators, liquid culturing,
    mechanical pipetting)

Laboratory Acquired Infection (LAI) History: Unknown

Laboratory Handling Guidelines 

Laboratory Biosafety Level (BSL): BSL-2


Lab Engineering Controls Personal Protective Equipment
  • Eye Protection
  • Single gloves
  • Snap-front lab coat with cinch cuffs

Waste Management: Regulated Medical Waste (RMW)

Shipping Guidance: Refer to EHS Biological Materials Shipping 

Animal Vivarium Guidance

Animal Housing Biosafety Level (ABSL): ABSL-2

Animal Biosecurity: Experimental animals are housed separately

Perform InoculationsBenchtop, Biosafety Cabinet, Cage Changing Station

Change CagesBenchtop, Biosafety Cabinet, Cage Changing Station

Exposure and Spill Procedures 

Mucous Membranes: Flush eyes, mouth, or nose for 15 minutes at an eyewash station. See: responding to exposures.

Other Exposures: Wash with soap and water for 15 minutes (open wounds, sores, etc.) or a minimum of 20 seconds for areas with intact skin. See: responding to exposures.

Small Spills: Notify others working in the lab. Evacuate area and allow 30 minutes for aerosols to settle. Don appropriate PPE. Cover area of the spill with paper towels and apply disinfectant, working from the perimeter toward the center. Allow 30 minutes of contact time before disposal and cleanup of spill materials. See: spill cleanup

Large Spills: Request assistance from the EHS Spill Team by calling CUPD dispatch. Call 911 from a campus phone or 607-255-1111 from a mobile phone.

Incident Reporting: Immediately report the incident to supervisor and complete the EHS online injury/illness report as soon as possible.

Medical Follow-Up:

  • For students, seek medical attention at Cornell Health or local primary care provider. Call Cornell Health at 607-255-5155 (24-hour phone consultation line) or a local urgent care. 
  • For faculty and staff, seek medical evaluation with a local primary care provider or urgent care. Cornell Health does not see employees for post-exposure care. 
  • Emergencies: Call 911 from a campus phone or 607-255-1111 from a mobile phone. 
Cornell EHS would like to thank Emory University for the use of their Biological Agent Reference Sheet (BARS) format and some content. 

More Information


  1. Block SS. Disinfection, sterilization, and preservation. Philadelphia, PA: Lippincott Williams & Wilkins; 2001.
  2. Broadley SJ, Furr JR, Jenkins PA, Russell AD. Antimycobacterial activity of “Virkon.” J Hosp Infect. 1993;23: 189–197. doi:10.1016/0195-6701(93)90024-T
  3. Chacon O, Bermudez LE, Barletta RG. Johne’s Disease, Inflammatory Bowel Disease, and Mycobacterium paratuberculosis. Annu Rev Microbiol. Annual Reviews; 2004;58: 329–
  4. Collins MT. Paratuberculosis: review of present knowledge. Acta Vet Scand. 2003a;44: 217–21. Available
  5. Collins MT. Update on paratuberculosis 1: Epidemiology. Ir Vet J. 2003b;56: 565 – 574.
  6. Manning EJ. Mycobacterium avium subspecies paratuberculosis: a review of current knowledge. J Zoo Wildl Med. American Association of Zoo Veterinarians; 2001;32: 293–304. doi:10.1638/1042-7260(2001)032[0293:MASPAR]2.0.CO;2
  7. Thorel M-F, Krichevsky M, Vincent Levy-Frebault V. Numerical Taxonomy of Mycobactin-Dependent Mycobacteria, Emended Description of Mycobacterium avium, and Description of Mycobacterium avium subsp. avium subsp. nov., Mycobacterium avium subsp. paratuberculosis subsp. nov., and Mycobacterium avium subsp. s. Int J Syst Bacteriol. Microbiology Society; 1990;40: 254–260.
  8. Whittington RJ, Marshall DJ, Nicholls PJ, Marsh IB, Reddacliff LA. Survival and dormancy of Mycobacterium avium subsp. paratuberculosis in the environment. Appl Environ Microbiol. 2004;70: 2989–3004.