Vitor Luz Carvalho

Metazoan parasites of cetaceans off the northeastern coast of Brazil

This study represents the first survey of the parasitic fauna of cetaceans off the northeastern coast of Brazil. Parasites were collected from 82 animals rescued from the states of Ceará to Bahia, including the archipelago of Fernando de Noronha. A total of 14 species of cetaceans were evaluated: Sotalia guianensis, Stenella sp., Stenella clymene, Stenella longirostris, Stenella coeruleoalba, Stenella frontalis, Megaptera novaeangliae, Peponocephala electra, Steno bredanensis, Kogia breviceps, Kogia sima, Globicephala macrorhynchus, Tursiops truncatus, Physeter macrocephalus and Lagenodelphis hosei. The parasites were fixed and preserved in 70% ethanol or alcohol-formalin-acetic acid solution (AFA), clarified in phenol and mounted on slides for morphological identification. In total, 11 species and 8 genera of endo- and ectoparasites were identified: Halocercus brasiliensis, Halocercus kleinenbergi, Stenurus globicephalae, Halocercus sp., Anisakis sp., Crassicauda sp. (Nematoda), Phyllobothrium delphini, Monorygma grimaldii, Scolex pleuronectis, Strobicephalus triangularis, Tetrabothrius forsteri, Tetrabothrius sp., Trigonocotyle sp., Diphyllobothrium sp. (Cestoda), Campula sp. (Trematoda), Bolbosoma sp. (Acanthocephala), Cyamus boopis, Syncyamus pseudorcae and Xenobalanus globicipitis (Crustacea). The identification of some species represented novel records for the country and increased the occurrence of some parasites to new hosts. The use of standardized methodologies for collecting and evaluating a larger number of animals is essential for a better understanding of host-parasite relationships in cetaceans and their use as biological indicators in the region.

Candida tropicalis isolates obtained from veterinary sources show resistance to azoles and produce virulence factors

Candida tropicalis has been associated with invasive candidiasis, being the first or second most common non-Candida albicans Candida species isolated in humans with candidemia and candiduria, as well as being frequently isolated from healthy animals. This study aimed to characterize C. tropicalis isolates (n = 64) obtained from several animal species regarding antifungal susceptibility and production of virulence factors. The isolates were obtained from the microbiota of healthy animals (goats, n = 25; sheep, n = 6; psittacines, n = 14; rheas, n = 6; horses, n = 2; sirenians, n = 5; shrimp, n = 1), as well as from aquatic mammals found dead in the environment (cetaceans, n = 5). The isolates were subjected to in vitro susceptibility testing by broth microdilution according to the CLSI M27-A3 protocol against amphotericin B, caspofungin, itraconazole, and fluconazole. We also evaluated the virulence attributes, such as proteases and phospholipases, as well as biofilm formation. Resistance to itraconazole (n = 29) and fluconazole (n = 30) was detected among isolates from every source; resistance to both azoles was detected in 24 isolates, but none of them were resistant to amphotericin B and caspofungin. Protease production was detected in the majority of the isolates (n = 59), but phospholipase was produced by only a few of them (n = 6). The isolates showed different patterns in biofilm production, being considered strong producers (n = 41), moderate producers (n = 11), weak producers (n = 9) or non-producers (n = 3). In summary, C. tropicalis isolated from animals showed high rate of resistance to azoles, expressed virulence factors and therefore may represent a potential threat to human and animal health.

Genetic analysis of Anisakis typica (Nematoda: Anisakidae) from cetaceans of the northeast coast of Brazil: New data on its definitive hosts

Anisakids from 5 different species of cetacean, Kogia breviceps, Peponocephala electra, Stenella clymene, Stenella longirostris and Steno bredanensis, were submitted to genetic analysis. Adults and larvae fixed in ethanol-formalin-acetic acid or in 70% ethanol for periods ranging from 10 months to 10 years were isolated from 9 cetaceans stranded on Ceará coast, Northeast Brazil. The 18S rDNA gene, ITS1, and specific Anisakis typica ITS regions were amplified by PCR. 18S rDNA and ITS1 region confirmed Anisakis sp. morphological identification but also detected the presence of Aspergillus sp. in longer preserved samples. All samples were identified as A. typica by ITS species-specific PCR. The study report three new definitive hosts of A. typica from the Brazilian Atlantic coast by genetic analysis: P. electra, K. breviceps, and S. clymene.

Organochlorine concentrations (PCBs, DDTs, HCHs, HCB and MIREX) in delphinids stranded at the northeastern Brazil.

Organochlorine compounds are highly persistent in the environment, causing bioaccumulation and biomagnification through the marine food chain. To verify the bioaccumulation pattern of DDT and its metabolites, as well as PCBs, Mirex, HCHs and HCB, samples of subcutaneous adipose tissue from 25 Guiana dolphins (Sotalia guianensis), two Frasers dolphins (Lagenodelphis hosei), two spinner dolphins (Stenella longirostris), one spotted dolphin (Stenella frontalis), and one striped dolphin (Stenella coeruleoalba) were analyzed. The collected specimens were found stranded in northeastern Brazil between 2005 and 2011. The concentrations were reported in μg·g(-1) lip, varying from 0.02 to 17.3 for ΣPCB, from 0.003 to 5.19 for ΣDDT, from 0.005 to 0.16 for ΣHCH, from 0.002 to 0.16 for HCB, and from 0.02 to 2.38 for Mirex. The PCBs dominated the bioaccumulation pattern for both the Guiana and spinner dolphins; for the other species, DDT was the major compound. A discriminant function analysis revealed the differences in the organochlorine accumulation patterns between the Guiana dolphin (S. guianensis) and the continental shelf/oceanic dolphins (S. frontalis and S. longirostris). The results also show that the concentrations of organochlorine compounds found in the delphinids in northeastern Brazil were lower than the delphinids found in other regions of Brazil, as well as other locations worldwide with intense agroindustrial development and/or a larger population.

Morphological and genetic identification of Anisakis paggiae (Nematoda: Anisakidae) in dwarf sperm whale Kogia sima from Brazilian waters

Anisakid nematodes have been identified in a wide variety of fish and marine mammal species. In Brazil, Anisakis physeteris, A. insignis, A. typica, A. nascetti, and those of the A. simplex complex have been reported infecting fishes and cetaceans. In this study, specimens collected from a dwarf sperm whale Kogia sima (Owen, 1866) stranded on the northeastern coast of Brazil were identified through morphological and genetic analyses as A. paggiae. Anisakids were examined through differential interference contrast light and scanning electron microscopy (SEM). Morphological and morphometric analysis revealed that these specimens belonged to Anisakis sp. clade II and more specifically to A. paggiae, exhibiting a violin-shaped ventriculus and 3 denticulate caudal plates, which are taxonomic characters considered unique to this species. Genetic analysis based on the mtDNA cox2 gene confirmed our identification of A. paggiae. Phylogenetic trees using both maximum likelihood and neighbor-joining methods revealed a strongly supported monophyletic clade (bootstrap support = 100%) with all available A. paggiae sequences. Integrative taxonomic analysis allowed the identification of A. paggiae for the first time in Brazilian waters, providing new data about their geographical distribution. Moreover, here we present the first SEM images of this species.

Morphological analysis of lymph nodes in Odontocetes from north and northeast coast of Brazil.

The morphology and location of lymph nodes from seven species of Odontocetes, of both sexes and different age groups, were described. All animals were derived from stranding events along the North and Northeastern coasts of Brazil. After the identification of lymph nodes in situ, tissue samples were analyzed for light and electron microscopy. Vascular volume density (VVD) and vascular length density (VLD) were evaluated in the mesenteric lymph nodes. Lymph nodes occurred as solitary nodules or in groups, varying in shape and size. In addition to using the nomenclature recommended by Nomina Anatomica Veterinaria, new nomenclatures were suggested based on the lymph nodes topography. Lymph nodes were covered by a highly vascularized and innervated capsule of dense connective tissue, below which muscle fibers were observed, inconsistently, in all studied species. There was no difference in VLD among different age groups. However, VVD was higher in adults. Lymph nodes parenchyma was divided into an outer cortex, containing lymph nodules and germinal centers; a paracortical region, transition zone with dense lymphoid tissue; and an inner medulla, composed of small irregular cords of lymphatic tissue, blood vessels, and diffuse lymphoid tissue. Abundant collagen fibers were observed around arteries and arterioles. Germinal centers were more evident and developed in calves and young animals, being more discrete and sparse in adults. The morphology of lymph nodes in Odontocetes was typical of that observed in other terrestrial mammals. However, new groups of lymph nodes were described for seven species occurring in the Brazilian coast. Anat Rec, 297:939–948, 2014.

Pulmonicola cochleotrema (Digenea: Opisthotrematidae) in Antillean manatees ( Trichechus manatus manatus ) from the North-eastern region of Brazil

BORGES, Joao Carlos Gomes et al. Pulmonicola cochleotrema (Digenea: Opisthotrematidae) in Antillean manatees (Trichechus manatus manatus) from the North-eastern region of Brazil. Journal of the Marine Biological Association of the United Kingdom, Plymunt, p. 1-4, jul. 2016.

Bipolaris hawaiiensis as an emerging cause of cutaneous phaeohyphomycosis in an Antillean manatee Trichechus manatus manatus.

Phaeohyphomycoses are emerging and opportunistic diseases caused by dematiaceous fungi that infect many animal species. This paper describes a case of cutaneous phaeohyphomycosis in an Antillean manatee Trichechus manatus manatus caused by Bipolaris hawaiiensis. Blackish skin lesions were observed in an Antillean manatee calf held captive in Brazil. Direct examination of skin scraping from the affected areas revealed the presence of dematious hyphae. Culture of skin fragments led to the isolation and subsequent identification of B. hawaiiensis as the etiologic agent. Treatment with itraconazole for 14 d was effective. Infections by Bipolaris spp. are rare in animals, and this is the first report of B. hawaiiensis in veterinary medicine.

Yeast microbiota of natural cavities of manatees (Trichechus inunguis and Trichechus manatus) in Brazil and its relevance for animal health and management in captivity.

The aim of this study was to characterize the yeast microbiota of natural cavities of manatees kept in captivity in Brazil. Sterile swabs from the oral cavity, nostrils, genital opening, and rectum of 50 Trichechus inunguis and 26 Trichechus manatus were collected. The samples were plated on Sabouraud agar with chloramphenicol and incubated at 25 °C for 5 days. The yeasts isolated were phenotypically identified by biochemical and micromorphological tests. Overall, 141 strains were isolated, of which 112 were from T. inunguis (Candida albicans, Candida parapsilosis sensu stricto, Candida orthopsilosis, Candida metapsilosis, Candida guilliermondii, Candida pelliculosa, Candida tropicalis, Candida glabrata, Candida famata, Candida krusei, Candida norvegensis, Candida ciferri, Trichosporon sp., Rhodotorula sp., Cryptococcus laurentii) and 29 were from T. manatus (C. albicans, C. tropicalis, C. famata, C. guilliermondii, C. krusei, Rhodotorula sp., Rhodotorula mucilaginosa, Rhodotorula minuta, Trichosporon sp.). This was the first systematic study to investigate the importance of yeasts as components of the microbiota of sirenians, demonstrating the presence of potentially pathogenic species, which highlights the importance of maintaining adequate artificial conditions for the health of captive manatees.

First record of Xenobalanus globicipitis (Cirripedia: Coronulidae) on Stenella coeruleoalba (Cetacea: Delphinidae) in the oligotrophic waters of north-eastern Brazil

The present contribution reports for the first time the sessile barnacle Xenobalanus globicipitis as an epizoic of the striped dolphin Stenella coeruleoalba in the oligotrophic waters of north-eastern Brazil. One barnacle specimen was found on a dead cetacean in Ceara State, north-eastern Brazil. Diagnosis and figures of the barnacle are provided and the relationship between the epizoic and the host discussed.