17 research outputs found
Wildlife Tuberculosis: An Emerging Threat for Conservation in South Asia
Wildlife tuberculosis (TB) is becoming one of the emerging challenges for conservation globally. South Asian region is home to many endangered species like Asian elephants, rhinoceros, and Bengal tigers. Although it carries more than one‐third of global burden of human TB, TB in livestock and wildlife has not been adequately studied. This chapter reviews the present knowledge and information about animal‐adapted members of Mycobacterium tuberculosis complex and wildlife TB in South Asia. Recent studies of TB from different wild animals in Nepal and Bangladesh have found that M.orygis is an emerging threat of wildlife TB in the region. These studies have demonstrated wide diversity of M. orygis strains circulating in the region indicating its endemic distribution. M. orygis–associated TB was discovered from a free‐ranging rhinoceros in Nepal and the finding could signify threat of TB in other wild animals, including a possibility of unknown maintenance host. Recent studies also revealed an emerging challenge caused by TB to elephants in different South Asian countries like Nepal, India, and Sri Lanka. Wildlife TB is becoming a conservation challenge in South Asia, but given the paucity of research in this area, it is overlooked and underexplored
Molecular characterization of Mycobacterium tuberculosis isolates from elephants of Nepal
Mycobacterium tuberculosis was cultured from the lung tissues of 3 captive elephants in Nepal that died with extensive lung lesions. Spoligotyping, TbD1 detection and multi-locus variable number of tandem repeat analysis (MLVA) results suggested 3 isolates belonged to a specific lineage of Indo-Oceanic clade, EAI5 SIT 138. One of the elephant isolates had a new synonymous single nucleotide polymorphism (SNP) T231C in the gyrA sequence, and the same SNP was also found in human isolates in Nepal. MLVA results and transfer history of the elephants suggested that 2 of them might be infected with M. tuberculosis from the same source. These findings indicated the source of M. tuberculosis infection of those elephants were local residents, presumably their handlers. Further investigation including detailed genotyping of elephant and human isolates is needed to clarify the infection route and eventually prevent the transmission of tuberculosis to susceptible hosts. (C) 2014 Elsevier Ltd. All rights reserved
Serodiagnosis of elephant tuberculosis: a useful tool for early identification of infected elephants at the captive-wild interface
Tuberculosis (TB) is an emerging disease in elephants primarily caused by Mycobacterium tuberculosis (M. tb) and in some occassion by M. bovis. We performed culture and three serological teststhe Elephant TB STAT-PAK,(R) DPP VetTB (R) Assay, and MAPIA (multi-antigen print immunoassay)prospectively on samples from eight elephants in Nepal that died of suspected or confirmed tuberculosis (TB) between 2007 and 2013. Among them, all elephants were reactive to DPP VetTB (R) Assay, five to Elephant TB STAT-PAK,(R) and two were reactive to MAPIA. Similarly, six elephants were positive on culture on samples collected antemortem or postmortem. We observed antibody responses months to years before culture confirmation of TB which shows that serological tests can be highly useful for the early diagnosis of TB in elephants. Validated point-of-care serological tests are easily performed in the field and hold promise for improved TB surveillance in other non-domestic species
Comparison of cortisol and thyroid hormones between tuberculosis-suspect and healthy elephants of Nepal
Molecular characterization of Mycobacterium tuberculosis isolates from elephants of Nepal
Mixed Mycobacterium tuberculosis Lineage Infection in 2 Elephants, Nepal
Tuberculosis in elephants is primarily caused by Mycobacterium tuberculosis. We identified mixed M. tuberculosis lineage infection in 2 captive elephants in Nepal by using spoligotyping and large sequence polymorphism. One elephant was infected with Indo-Oceanic and East African–Indian (CAS-Delhi) lineages; the other was infected with Indo-Oceanic and East Asian (Beijing) lineages
Development and evaluation of an interferon-γ release assay in Asian elephants (Elephas maximus)
We developed an interferon-γ release assay (IGRA) specific for Asian elephants (Elephas maximus). Whole blood collected from forty captive Asian elephants was stimulated with three different mitogens i.e., phytohemagglutinin (PHA), pokweed mitogen (PWM) and phorbol myristate aceteate/ionomycin (PMA/I). A sandwich ELISA that was able to recognize the recombinant elephant interferon-γ (rEIFN-γ) as well as native interferon-γ from the Asian elephants was performed using anti-elephant IFN-γ rabbit polyclonal antibodies as capture antibodies and biotinylated anti-elephant IFN-γ rabbit polyclonal antibodies as detection antibodies. PMA/I was the best mitogen to use as a positive control for an Asian elephant IGRA. The development of an Asian elephant-specific IGRA that detects native IFN-γ in elephant whole blood provides promising results for its application as a potential diagnostic tool for diseases, such as tuberculosis (TB) in Asian elephants