Molecular Detection and Characterization of Mycoplasma spp. in Marine Mammals, Brazil.

Mycoplasma spp. are wall-less bacteria able to infect mammals and are classified as hemotropic (hemoplasma) and nonhemotropic. In aquatic mammals, hemoplasma have been reported in California sea lions (Zalophus californianus) and river dolphins (Inia spp.). We investigated Mycoplasma spp. in blood samples of West Indian manatees (Trichechus manatus), pinnipeds (5 species), and marine cetaceans (18 species) that stranded or were undergoing rehabilitation in Brazil during 2002-2022. We detected Mycoplasma in blood of 18/130 (14.8%) cetaceans and 3/18 (16.6%) pinnipeds. All tested manatees were PCR-negative for Mycoplasma. Our findings indicate that >2 different hemoplasma species are circulating in cetaceans. The sequences from pinnipeds were similar to previously described sequences. We also detected a nonhemotropic Mycoplasma in 2 Franciscana dolphins (Pontoporia blainvillei) that might be associated with microscopic lesions. Because certain hemoplasmas can cause disease and death in immunosuppressed mammals, the bacteria could have conservation implications for already endangered aquatic mammals.

Herpesvirus and adenovirus surveillance in threatened wild West Indian (Trichechus manatus) and Amazonian manatees (Trichechus inunguis), Brazil.

THE FAMILY TRICHECHIDAE (ORDER SIRENIA) COMPRISES THREE SPECIES: African (Trichechus senegalenses), West Indian (T. manatus), WIM)], and the Amazonian manatees (T. inunguis, AMM). Whereas WIM inhabits both riverine and coastal systems in the western Atlantic, AMM is the only exclusively freshwater sirenian, endemic to the Amazon River Basin. The study of infectious agents is essential to species conservation, especially considering that both species are classified as Vulnerable by the IUCN Red List and as Endangered by the Brazilian Red List. The current knowledge about viral agents in sirenians is scarce. Herpesviruses and adenovirus are DNA viruses able to infect and cause disease in a wide range of hosts. Herein, we used panPCR protocols to survey herpesvirus and adenovirus in blood samples of wild WIM (n = 23) and AMM (n = 26) under human care in Brazil. Herpesvirus DNA was detected in one juvenile female WIM (1/23; 4.3%; 95% CI -4.7 - 13.3) from Ceará state and in four AMM (two juvenile females, a juvenile male, and an adult female; 4/26; 15.4%; 95% CI 0.5 - 30.3) from Amazonas state. The two different gammaherpesvirus DNA polymerase sequence types identified (one per species, a sequence type in a WIM and another one in three AMM) were highly similar (99% nucleotide identity) to Trichechid herpesvirus 1, reported in West Indian manatees of Florida (USA), and 100% identical when translated into amino acids. A herpesviral glycoprotein B sequence was identified in two AMM. None of the samples was positive to adenovirus. To the authors' knowledge, this is the first herpesvirus detection in manatees from South America, expanding the herpesvirus geographical range, and the first in WIM and AMM worldwide. Our findings suggest (i) that West Indian and Amazonian manatees are possibly the natural hosts of the detected herpesvirus, and (ii) coevolution of that gammaherpesvirus with Trichechus. Future studies are necessary to characterize the obtained virus and elucidate potential pathological effects (if any) in these species.

Hemotropic Mycoplasma spp. in Aquatic Mammals, Amazon Basin, Brazil.

Hemotropic Mycoplasma spp. (hemoplasmas) are uncultivable bacteria that infect mammals, including humans. We detected a potentially novel hemoplasma species in blood samples from wild river dolphins in the Amazon River Basin, Brazil. Further investigation could determine pathogenicity and zoonotic potential of the detected hemoplasma.

Case report of respiratory aspergillosis and candidiasis in wild Magellanic penguins (Spheniscus magellanicus), Brazil.

Magellanic penguins (Spheniscus magellanicus) migrate to the continental shelf of southern-southeastern Brazil during austral winter. Stranded penguins are directed to rehabilitation centers, where they occasionally develop fungal diseases. Aspergillosis, a mycosis caused by Aspergillus spp., is one of the most important diseases of captive penguins, while Candida sp. has been detected in penguins undergoing rehabilitation. Nevertheless, their occurrence in the wild is poorly understood. This study surveyed the occurrence of mycoses in free-ranging Magellanic penguins wintering in southeastern Brazil. These penguins were either found dead or stranded alive and died during transport to a rehabilitation center. Overall, 61 fresh to moderate autolyzed carcasses were necropsied. Upon necropsy, three juvenile males (4.9%) presented mycotic-consistent gross lesions. Histopathology and panfungal PCRs confirmed the mycoses. Major microscopic findings were marked chronic necrotizing multifocal to coalescent pneumonia, airsacculitis, and esophageal/gastric serositis with two types of intralesional fungal structures: (a) septated acute-angled branching hyphae (n = 2) and (b) yeast structures (n = 1), both PAS- and Grocott-positive. Sequences identical to Aspergillus sp. were retrieved in two cases, while the third had sequences identical to Candida palmioleophila. This study describes two cases of aspergillosis and one of candidiasis in free-ranging Magellanic penguins, confirming the species' susceptibility in the wild. These mycoses could be associated with the animals' poor body condition, and/or impaired immunity, and natural and anthropogenic challenges related to migration. To the authors' knowledge, this is the first report of aspergillosis in free-ranging Magellanic penguins in the Atlantic Ocean and of candidiasis in penguins worldwide.