Fatal balamuthosis in a Siberian tiger and a literature review of detection options for free-living amoebic infections in animals.

Free-living amoebae are rare causes of morbidity and mortality in humans and animals around the globe. Because the route of exposure and clinical progression of disease caused by different species of amoebae may vary in people and animals, determining the species of amoeba present is important. We describe here a fatal infection by the free-living amoeba Balamuthia mandrillaris in a Siberian tiger (Panthera tigris altaica). The 17-y-old patient had a rapid clinical decline after a peracute onset of severe lethargy, dull mentation, and anorexia. Autopsy did not identify a cause of death. Histology revealed inflammation associated with amoebic trophozoites in the brain, lungs, and iris of one eye. These amoebae were confirmed to be B. mandrillaris based on a PCR assay and sequencing. Although there are subtle morphologic differences between cyst stages of Acanthamoeba spp., B. mandrillaris, and Naegleria fowleri when present and identified on routine staining, other modalities, including PCR, immunofluorescence, electron microscopy, and immunohistochemistry, are typically utilized to confirm the pathogen involved in these cases. We review the reports of balamuthosis in animals.

PULMONARY AND COELOMIC MYCOSES DUE TO METARHIZIUM AND BEAUVERIA SPECIES IN REPTILES.

This report documents cases of fatal pulmonary mycosis caused by entomopathogenic fungi in the genera Metarhizium and Beauveria (Order Hypocreales) in a loggerhead sea turtle (Caretta caretta), a Chinese alligator (Alligator sinensis), two gopher tortoises (Gopherus polyphemus), a Cuvier's dwarf caiman (Paleosuchus palpebrosus), a false gharial (Tomistoma schlegelii), a green sea turtle (Chelonia mydas), and a Kemp's ridley sea turtle (Lepidochelys kempii), and a case of granulomatous coelomitis in a hawksbill sea turtle (Eretmochelys imbricata). Fungi identified in these cases included Beauveria bassiana, Beauveria brongniartii, Metarhizium anisopliae, Metarhizium robertsii, and one case of infection by a novel Metarhizium species. The animals were either housed at zoos or brought into rehabilitation from the wild. Although the majority of animals had comorbidities, the fungal infections were believed to be the primary cause of death. Fungal susceptibility testing was performed on two Beauveria spp. isolates, and revealed lower minimum inhibitory concentrations for itraconazole and voriconazole when compared to terbinafine and fluconazole. This case series demonstrates that a variety of reptile species from different orders are vulnerable to infection with Metarhizium, and multiple species of sea turtle are susceptible to infection with Beauveria.

Field application of serodiagnostics to identify elephants with tuberculosis prior to case confirmation by culture.

Three serologic methods for antibody detection in elephant tuberculosis (TB), the multiantigen print immunoassay (MAPIA), ElephantTB STAT-PAK kit, and DPP VetTB test, were evaluated using serial serum samples from 14 captive elephants infected with Mycobacterium tuberculosis in 5 countries. In all cases, serological testing was performed prior to the diagnosis of TB by mycobacterial culture of trunk wash or tissue samples collected at necropsy. All elephants produced antibody responses to M. tuberculosis antigens, with 13/14 recognizing ESAT-6 and/or CFP10 proteins. The findings supported the high serodiagnostic test accuracy in detecting infections months to years before M. tuberculosis could be isolated from elephants. The MAPIA and/or DPP VetTB assay demonstrated the potential for monitoring antimycobacterial therapy and predicting TB relapse in treated elephants when continuously used in the posttreatment period. History of exposure to TB and past treatment information should be taken into consideration for proper interpretation of the antibody test results. Data suggest that the more frequent trunk wash culture testing of seropositive elephants may enhance the efficiency of the TB diagnostic algorithm, leading to earlier treatment with improved outcomes.

Salmon poisoning disease in two Malayan sun bears.

CASE DESCRIPTION: 2 captive sun bears (Helarctos malayanus) were evaluated because of acute onset of vomiting, mucoid diarrhea, lethargy, and anorexia 1 week after eating live trout from a northern California reservoir. CLINICAL FINDINGS: In 1 of the bears, a CBC and serum biochemical analyses revealed mild anemia, mild eosinophilia, moderate lymphopenia, moderate hypoalbuminemia, and high serum G-glutamyltransferase activity. Ultrasonographic examination of the same bear revealed ascites and mesenteric lymphadenopathy. Histologic examination of gastrointestinal tract biopsy specimens revealed moderate to severe lymphoplasmacytic and eosinophilic gastritis, enteritis, and colitis. Ova of Nanophyetus salmincola, the trematode vector of Neorickettsia helminthoeca (a rickettsial organism that causes salmon poisoning disease), were detected in fecal samples from both bears. TREATMENT AND OUTCOME: The bears were treated with oxytetracycline, doxycycline, praziquantel, and famotidine. Within 1 week after initiation of treatment, the appetite and fecal consistency of each bear were considered normal. Fecal ova shedding began 4 days after onset of clinical signs and ceased 9 days later. CLINICAL RELEVANCE: Salmon poisoning disease can be rapidly fatal in untreated animals, but if diagnosed early and treated appropriately, full recovery can be achieved. Domestic dogs and captive exotic bears are highly susceptible to clinical disease after ingestion of trematode-infected fish. Salmon poisoning disease may develop outside the geographic range in which the causative organism is endemic as a result of the transplantation of infected fish for sport fishing; veterinarians practicing in areas where infected fish may be transplanted should be aware of appropriate diagnostic and treatment protocols.