Oxidative and osmotolerant effects in Salvator merianae (Squamata: Teiidae) red blood cells during hibernation

Hibernation is a natural condition of animals that lives in the temperate zone, although some tropical lizards also experience hibernation annually, such as the lizard native from South America, Salvator merianae, or “tegu” lizard. Even though physiological and metabolic characteristic associated with hibernation have been extensively studied, possible alterations in the red blood cells (RBC) integrity during this period remains unclear. Dehydration and fasting are natural consequences of hibernating for several months and it could be related to some cellular modifications. In this study, we investigated if the osmotic tolerance of RBCs of tegu lizard under hibernation is different from the cells obtained from animals while normal activity. Additionally, we indirectly investigated if the RBCs membrane of hibernating tegus could be associated with oxidation by quantifying oxidized biomolecules and the activity of antioxidant enzymes. Our findings suggest that RBCs are more fragile during the hibernation period, although we did not find evidence of an oxidative stress scenario associated with the accentuated fragility. Even though we did not exclude the possibility of oxidative damage during hibernation, we suggested that an increased RBCs volume as a consequence of hypoosmotic blood during hibernation could also affect RBCs integrity as noted.

Leptospira interrogans infection in tegu lizard (Tupinambis merianae), Brazil

ABSTRACT: We used 12 tegu lizards (Tupinambis merianae) from northeastern Brazil, and we reported nine (75%) Leptospira sp. PCR-positive animals and six (50%) seropositive. Leptospira sp. DNA sequencing revealed 99% similarity with L. interrogans. Our findings indicated that this species may play a role in the transmission of human leptospirosis.

Eggs of tegu lizard, Salvator merianae (Duméril & Bilbron, 1839) (Squamata; Teiidae) damaged by fungal infections

The tegu (Salvator merianae) is the largest lizard found in Brazil and has a wide distribution, occurring in several biomes. The presence of fungi on reptilian eggs initially occurs on infertile eggs, which leads to a subsequent infection in fertile eggs, causing damage and death of embryos. The objective of this study was to identify the fungi that caused lesions in the eggs of tegu in captivity. Swabs were collected on infected and healthy eggshells, in an embryo that died and the substrate of the incubation box. Samples were submitted to saboraund dextrose agar. A total of 93.3% of positive samples were obtained for the fungi Fusarium (11/14), Trichoderma (1/15), Penicilium (1/15), Mucor (1/15), and yeasts of the genus Trichosporon. Therefore, Fusarium was the main agent that caused the lesion and death of embryos in the eggs of the tegu lizard. Sanitary control methods may be taken to avoid fungal infections in the eggs.