Systemic Mycobacterium kansasii Infection in Two Related Cats

Abstract

Mycobacterial infections are a major concern in veterinary medicine because of the difficulty achieving an etiological diagnosis, the challenges and concerns of treatment, and the potential zoonotic risk. Mycobacterium kansasii, a slow-growing non-tuberculous mycobacteria, causes disease in both humans and animals. While infections have been well described in humans, where it may be misdiagnosed as tuberculosis, there are fewer reports in animals. Only four cases have been reported in the domestic cat. This case report describes systemic M. kansasii infection in two sibling indoor-only cats that presented two and half years apart with cutaneous disease that was found to be associated with osteolytic and pulmonary pathology. Infection with M. kansasii was confirmed in both cats by polymerase chain reaction on fine-needle aspirate of a lumbosacral soft tissue mass in one cat and on a tissue punch biopsy of a skin lesion in the other; interferon-gamma release assay inferred M. avium-complex and M. tuberculosis-complex infection in the two cats, respectively. Both patients made a full recovery following antimicrobial therapy with rifampicin, azithromycin, and pradofloxacin (plus N-acetyl cysteine in cat 2). This report highlights successful treatment of systemic M. kansasii mycobacteriosis in the cat and the challenge of accurately diagnosing this infection.

Clinical resolution of systemic mycobacterial infection in a cat with a suspected spinal granuloma

“…[1][2][3][4]9 Interestingly, in the cat with vertebral lesions associated with M. kansasii previously reported in the literature, remission of clinical signs was achieved and resolution of the osteolytic lesions was documented 4 months after starting antimycobacterial treatment. 11 Overall, the prognosis in our case was considered guarded. Additionally, there were concerns about the need for prolonged antibiotic therapy, 3,9 with the inherent risk of toxicity and the necessity for owners and patient compliance.…”

“…To the authors’ knowledge, an intradural‐extramedullary granuloma has not been previously reported in cats infected with M. microti . Spinal mycobacteriosis associated with two species of NTM ( M. avium and M. kansasii ) in cats has been reported 10,11 . The cat diagnosed with M. kansasii had a mass lesion causing osteolytic changes at the level of the caudal vertebral bodies 11 ; detailed clinical information about the spinal lesions associated with M. avium has not yet been published 10 …”

Development of an enzyme-linked immunosorbent assay for the diagnosis of feline tuberculosis

“…Positive antibody responses to MPB83 have been reported in cats, but the performance for M. microti-infected cats was poor compared to those infected with M. bovis (Rhodes et al, 2011). It is also possible that NTM could incite responses to this major mycobacterial protein, such as M. kansasii, which has been reported in cats (Lee et al, 2017, Černá et al, 2020, Fukano et al, 2021, and so the concern for single-antigen testing in cats is the potential misdiagnosis of this infection as TB.…”

Human pathogenic Mycobacterium kansasii (former subtype I) with zoonotic potential isolated from a diseased indoor pet cat, Japan

“…M. kansasii has been isolated from a wide variety of animals; dogs ( Canis familiaris ), Rhesus Macaque ( Macaca mulatta ) and cats ( Felis catus ) [ 11–14 ]. To our knowledge, three cases of MKC infetion in cat were reported previously [ 12 , 14 ]. All the three cats were presented with cutaneous and systemic lesion.…”

“…In one case, the cat was treated with trimethoprim-sulphamethoxazole and doxycycline, but it was unsuccessful [ 12 ]. Other two cats were sibling, indoor-only cats and treated successfully with rifampicin, azithromycin and pradofloxacin [ 14 ]. In these cases, commercial identification kit or PCR sequence analysis using partial house keeping genes were performed for bacterial identification.…”