Co-infection of Mycobacterium tuberculosis complex and carbapenem-resistant hypervirulent Klebsiella pneumoniae in captive Asiatic black bears: A case report
Two male Asiatic black bears (Ursus thibetanus), aged 2 and 3 years, developed persistent diarrhea, which improved temporarily after penicillin and cephalosporin treatment but relapsed shortly after. Despite ongoing therapy, both showed progressive weight loss, lethargy, and depression. Five days before death, acute respiratory signs, including fever, tachypnea, and coughing, appeared, followed by rapid decline. Necropsy revealed extensive multisystemic lesions. Histopathological examination using Ziehl–Neelsen and Gram staining revealed intralesional acid-fast bacilli and Gram-negative bacilli, PCR amplification and sequencing of DNA extracted from lung tissue identified carbapenem-resistant hypervirulent Klebsiella pneumoniae strains carrying multiple virulence and resistance genes, as well as Mycobacterium tuberculosis complex.