Pasteurella pneumotropica

Prevalence
  • Common in laboratory research- and commercial rodent colonies
  • Highly prevalent, opportunistic pathogens in infected, experimental colonies
Significance
  • Immunodeficient animals may be prone to clinical disease
  • Immunocompetent animals may be useful in research if no clinical signs are seen
  • Considered to be of low significance in immunocompetent rats
Disease
  • Gram negative coccobacillus-shaped bacteria
  • Primarily colonized in the nasopharynx, lungs, digestive tract, caecum, vagina, uterus, and conjunctiva
  • Mostly asymptomatic, but clinical signs may develop with stress or an underlying predisposition and include:
    • panophthalmitis, dacryoadenitis, orbital abscesses, otitis, mastitis, genital tract infections, cervical lymphadenitis, metritis, conjunctivitis, rhinitis, inflammation of subcutaneous and adnexal tissues, tachypnea, dyspnea, facial alopecia, pulmonary abscesses, pneumonia, and sudden death
  • Nude - necrotizing and suppurative infection of the Harderian gland
  • Immunodeficient animals - retrobulbar abscesses involving the lacrimal gland
  • Co-infection with Mycoplasma pulmonis, Sendai virus, or Pneumocystis sp. may increase the respiratory symptoms and lesions
Transmission
  • Direct contact with infected animals or their secretions
  • Indirect exposure to contaminated bedding or other fomites
  • Vertical transmission is possible
Diagnosis
  • Preferred - Bacterial culture of nasotracheal wash
  • Nasopharyngeal swab culture
  • Vaginal or intestinal culture
  • PCR confirmation of suspected cultures
  • PCR of deparaffinized histological sections of suspect lesions
Strains
  • Rats and mice may be primary carriers
  • Immunodeficiency and stress are likely to produce clinical illness
Duration
  • Carrier status. 
Durability
  • Very sensitive obligate parasite
  • Regular cleaning with the use of disinfectants should work to clean the environment
  • Does not persist or multiply in the environment
Screening
  • Regular 
Prevention and Control
  • Soiled bedding sentinel monitoring programs may be unreliable for detection
  • Pathogen exclusion through rederivation by either embryo transfer or caesarean section is possible
  • Isolate offspring until confirmed negative
  • Treatment with a bacterial, broad spectrum, fluoroquinolone antibiotic such as Enrofloxacin that inhibits DNA gyrase has been described for the mouse
 
Reading
  • Hagit Dafni, Lea Greenfeld, Roni Oren, & Alon Harmalin. The Likelihood of Misidentifying Rodent Pasteurellaceae by Using Results from a Single PCR Assay. JALAAS, 2019, 58(2):1-7
  • Justin W. Towne, April M. Wagner, Kurt J. Griffin, Adam S. Buntzman, Jeffrey A. Frelinger, & David G. Besselsen. Elimination of Pasteurella pneumotropica from a Mouse Barrier Facility by Using a Modified Enrofloxacin Treatment Regimen. JALAAS, 2014, 53(5):517-522
  • Calvin C. Patten Jr, Matthew H. Myles, Craig L. Franklin, & Robert S. Livingston. Perturbations in Cytokine Gene Expression after Inoculation of C57BL/6 Mice with Pasteurella pneumotropica. Comparative Medicine, 2010, 60(1):18-24
  • Hiraku Sasaki, Eiichi Kawamoto, Yoshikazu Tanaka, Takuo Sawada, Satoshi Kunita, & Ken-ichi Yagami. Comparative analysis of Pasteurella pneumotropica isolates from laboratory mice and rats. Antonie van Leeuwenhoek, 2009, 95:311-317
  • Dean H. Percy & Stephen W. Barthold. Pathology of Laboratory Rodents and Rabbits, 2007, 4:146-147
  • Infectious Diseases of Mice and Rats, National Research Council, 1991​