RESUMO
A recently deceased juvenile male bottlenose dolphin (Tursiops truncatus) was found floating in the Gulf of Mexico, off Sand Key in Clearwater, Florida. At autopsy, we identified pneumonia and a focus of malacia in the right cerebrum. Cytologic evaluation of tissue imprints from the right cerebrum revealed fungal hyphae. Fungal cultures of the lung and brain yielded Aspergillus fumigatus, which was confirmed by amplification of a portion of the fungal nuclear ribosomal internal transcribed spacer 2 region sequence. Microscopic pulmonary lesions of bronchiolar epithelial cell syncytia with intracytoplasmic and intranuclear inclusions within bronchiolar epithelial cells were suggestive of Cetacean morbillivirus (CeMV) infection. The occurrence of CeMV infection was supported by positive immunohistochemical staining for morbillivirus antigen. CeMV detection was confirmed by amplification and sequencing a portion of the morbilliviral RNA-dependent RNA polymerase gene from lung tissue. This case provides CeMV sequence data available from the Gulf of Mexico and underscores the need for genomic sequencing across diverse host, temporospatial, and population (i.e., single animal vs. mass mortality events) scales to improve our understanding of these globally emerging pathogens.
Assuntos
Aspergilose/veterinária , Aspergillus fumigatus/isolamento & purificação , Golfinho Nariz-de-Garrafa , Infecções por Morbillivirus/veterinária , Morbillivirus/isolamento & purificação , Animais , Aspergilose/diagnóstico , Aspergilose/microbiologia , Coinfecção/veterinária , Golfo do México , Pulmão/patologia , Masculino , Infecções por Morbillivirus/diagnóstico , Infecções por Morbillivirus/microbiologiaRESUMO
An unusual mortality event (UME) was declared for cetaceans in the northern Gulf of Mexico (GoM) for Franklin County, Florida, west through Louisiana, USA, beginning in February 2010 and was ongoing as of September 2014. The 'Deepwater Horizon' (DWH) oil spill began on 20 April 2010 in the GoM, raising questions regarding the potential role of the oil spill in the UME. The present study reviews cetacean mortality events that occurred in the GoM prior to 2010 (n = 11), including causes, durations, and some specific test results, to provide a historical context for the current event. The average duration of GoM cetacean UMEs prior to 2010 was 6 mo, and the longest was 17 mo (2005-2006). The highest number of cetacean mortalities recorded during a previous GoM event was 344 (in 1990). In most previous events, dolphin morbillivirus or brevetoxicosis was confirmed or suspected as a causal factor. In contrast, the current northern GoM UME has lasted more than 48 mo and has had more than 1000 reported mortalities within the currently defined spatial and temporal boundaries of the event. Initial results from the current UME do not support either morbillivirus or brevetoxin as primary causes of this event. This review is the first summary of cetacean UMEs in the GoM and provides evidence that the most common causes of previous UMEs are unlikely to be associated with the current UME.