Heavy metals bioaccumulation in free-ranging South American rattlesnakes (Crotalus durissus) in Southeastern Brazil.

Anthropogenic activities are the main sources of soil, air, and water pollution by metals, including cadmium (Cd), lead (Pb), chromium (Cr), the metalloid arsenic (As), magnesium (Mg), zinc (Zn), and copper (Cu). The goal of this study was to assess the presence and concentration of toxic (As, Cd, Pb, and Cr) and essential metals (Mg, Zn, and Cu) in the liver and kidneys from 96 free-ranging rattlesnakes (Crotalus durissus) from Minas Gerais (Brazil). Bioaccumulation of Cd and Pb were significantly higher in males and heavier rattlesnakes (those with body weight above the average of the study population). Average ± standard deviations of Cd, Pb, Cr, Cu, Mg, Zn, and As in the general population (n = 96) were 3.19 ± 2.52; 5.98 ± 8.49; 0.66 ± 1.97; 3.27 ± 2.85; 776.14 ± 2982.92; 27.44 ± 29.55; and 0.32 ± 1.46; respectively. Bioaccumulation of some metals correlated positively with changes in hematologic and serum biochemical parameters. Results of this study were contrasted with previous studies assessing metal bioaccumulation in other species of terrestrial or aquatic snakes. Considering their position in the food chain and the broad range of bioaccumulation of both toxic and essential metals observed in this study, rattlesnakes may function as highly relevant biological sentinels for environmental pollution.

Histopathologic and immunophenotypic profile of a spontaneous mammary carcinoma in a male Humboldt's white-fronted capuchin (Cebus albifrons).

A 20-year-old male captive Humboldt's white-fronted capuchin (Cebus albifrons) that died accidentally had a small non-ulcerative mammary nodule diagnosed as a mammary carcinoma. Immunohistochemistry demonstrated that neoplastic cells were positive for pan-cytokeratin and cytokeratin-7. Approximately 20% of neoplastic cells were positive for Ki-67. Neoplastic cells expressed estrogen and progesterone receptors.

Histopathologic Patterns and Susceptibility of Neotropical Primates Naturally Infected With Yellow Fever Virus.

Yellow fever is an important zoonotic viral disease that can be fatal for both human and nonhuman primates. We evaluated histopathologic changes in free-ranging neotropical primates naturally infected with yellow fever virus (YFV) compared with uninfected cohorts. The most frequent lesions in primates infected with YFV were hepatic changes characterized by midzonal necrosis with lipidosis and mild inflammation including lymphocytes, macrophages, plasma cells, and infrequently neutrophils. Importantly, severe necrotizing hepatic lesions were often observed in Alouatta sp. (howler monkeys), whereas Callithrix sp. (common marmosets) had nearly no hepatic changes. Moderate to severe hepatic necrosis was present in 21/23 (91%) of the YFV-positive Alouatta sp. compared with 10/29 (34%) of the YFV-positive Callithrix sp. (P < .0001; odds ratio = 20). Similarly, hepatitis was more intense in Alouatta sp. compared with Callithrix sp. Furthermore, the frequency of YFV infection was significantly higher in Alouatta sp. compared with Callithrix sp. or Sapajus sp. (capuchin monkeys). Therefore, these data support the notion that Alouatta sp. is highly susceptible to infection and YFV-induced lesions, whereas Callithrix sp. is susceptible to infection but has a lower frequency of YFV-induced lesions.

Host range and susceptibility to Toxoplasma gondii infection in captive neotropical and Old-world primates.

BACKGROUND: Toxoplasmosis is an important disease affecting captive non-human primates. The goal of this study was to assess the seroprevalence and pathological findings of toxoplasmosis in different species of captive primates. METHODS: Six captive neotropical primates died naturally due to Toxoplasma gondii infection and were necropsied. Tissue samples were evaluated by histopathology and immunohistochemistry. Serum samples from 57 captive neotropical and Old-world primates housed at the Belo Horizonte zoological garden were analyzed by indirect fluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), and indirect hemagglutination assay (IHA). RESULTS: Neotropical primates had lesions compatible with toxoplasmosis with immunolabeled intralesional T gondii. All Old-World primates (10/10), but only three neotropical primates (3/47), all belonging to the Sapajus apella species (3/6), were serologically positive. CONCLUSIONS: Our results suggest a higher susceptibility of neotropical primates to toxoplasmosis. However, this study also supports the hypothesis that Sapajus apella may be naturally resistant.