COS 17-8 - Emerging tuberculosis pathogen hijacks social communication behavior in the group-living banded mongoose (Mungos mungo)

Tuesday, August 9, 2016: 10:10 AM
Palm B, Ft Lauderdale Convention Center
Kathleen A. Alexander, Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA, Claire E. Sanderson, Virginia Tech, Blacksburg, VA, Michelle L. Larsen, Department of Medicine, Albert Einstein College of Medicine, Bronx, N, NY, Suelee Robee-Austerman, Diagnostic Bacteriology Laboratory, National Veterinary Services Laboratories, Ames, Iowa, Ames, IA, Mark C. Williams, Department of Paraclinical Sciences, University of Pretoria, Pretoria, South Africa and Mitchell V. Palmer, Bacterial Diseases of Livestock Research Unit, National Animal Disease Center, Ames, IA
Background/Question/Methods: An emerging Mycobacterium tuberculosis complex (MtbC) pathogen, M. mungi, infects wild banded mongooses (Mungos mungo) in Northern Botswana causing significant mortality. This MtbC pathogen did not appear to be transmitted through a primary aerosol or oral route. We utilized histopathology, spoligotyping, MIRU-VNTR, qPCR, and molecular markers (regions of difference (RD)- RD1BCG, RD1mic, RD1seal; Rv1510 gene (RD4), Rv1970 gene (RD7), Rv3877/8 gene (RD1), Rv3120 gene (RD12), Insertion element IS1561, 16sRNA gene, Rv0577 (cfp32)) including the newly characterized mongoose-specific deletion in RD1 (RD1mon) in order to demonstrate the presence of M. mungi DNA in infected mongoose and investigate pathogen invasion and exposure mechanisms.

Results/Conclusions: M. mungi DNA was identified in 29% of nasal planum samples (n=52), 56% of nasal rinses and swabs (n=9), 53% of oral swabs (n=19), 22% of urine samples (n=23), 33% of anal gland tissue (n=18), and 39% of anal gland secretions (n=44). The occurrence of extremely low cycle threshold values with qPCR in anal gland and nasal planum samples indicate high levels of M. mungi can be found in these tissue types. Histological data were consistent with these results, suggesting that pathogen invasion occurs through breaks in the nasal planum and/or skin of the mongoose host which are in frequent contact with anal gland secretions and urine during olfactory communication behavior. Lesions in the lung, when present, occurred only with disseminated disease. No environmental sources of M. mungi DNA could be found. We report a novel mechanism of environmental pathogen transmission for the MtbC complex where pathogen movement and host exposure dynamics are driven by social behavior. The presence of M. mungi in environmentally deposited olfactory secretions effectively circumvents natural social barriers (e.g., territoriality) facilitating between-group pathogen transmission in the absence of direct physical contact, a rare occurrence in this highly territorial species.