Tuberculosis caused by Mycobacterium bovis infection in a captive-bred American bullfrog (Lithobates catesbeiana).

BACKGROUND: Tuberculosis is widely known as a progressive disease that affects endothermic animals, leading to death and/or economical losses, while mycobacterial infections in amphibians are commonly due to nontuberculous mycobacteria. To the authors' knowledge, this report describes the first case of bovine tuberculosis in a poikilothermic animal. CASE PRESENTATION: An adult female captive American bullfrog (Lithobates catesbeianus Shaw, 1802) died in a Brazilian aquarium. Multiple granulomas with acid-fast bacilli were observed in several organs. Identification of Mycobacterium bovis was accomplished by culture and PCR methods. The other animals from the same enclosure were euthanized, but no evidence of mycobacterial infection was observed. CONCLUSIONS: The American bullfrog was introduced in several countries around the world as an alternative husbandry, and its production is purposed for zoological and aquarium collections, biomedical research, education, human consumption and pet market. The present report warns about an episode of bovine tuberculosis in an amphibian, therefore further studies are necessary to define this frog species' role in the epidemiology of M. bovis.

Predicting the potential for zoonotic transmission and host associations for novel viruses.

Host-virus associations have co-evolved under ecological and evolutionary selection pressures that shape cross-species transmission and spillover to humans. Observed virus-host associations provide relevant context for newly discovered wildlife viruses to assess knowledge gaps in host-range and estimate pathways for potential human infection. Using models to predict virus-host networks, we predicted the likelihood of humans as hosts for 513 newly discovered viruses detected by large-scale wildlife surveillance at high-risk animal-human interfaces in Africa, Asia, and Latin America. Predictions indicated that novel coronaviruses are likely to infect a greater number of host species than viruses from other families. Our models further characterize novel viruses through prioritization scores and directly inform surveillance targets to identify host ranges for newly discovered viruses.

Occurrence of Sarcocystis falcatula in captive psittacine birds in Brazil.

Thirty-eight captive psittacine birds housed in a bird park in Foz do Iguaçu, Parana, Brazil, died within a 15-month period as a result of infection with Sarcocystis falcatula. Although fatalities affected 16 species of psittacine birds, mortality was highest in Old World species, which were most susceptible to the pulmonary form of sarcocystosis. Along with the pathologic findings of this disease outbreak, a review of the pathophysiology of sarcosporidiosis is presented.

Detection of Mycobacterium avium in pet birds.

The present study is a report on the presence of Mycobacterium avium in four birds of the psittaciform order kept as pets. Anatomopathological diagnosis showed lesions suggestive of the agent and presence of alcohol-acid resistant bacilli (AARB) shown by the Ziehl-Neelsen staining. The identification of Mycobacterium avium was performed by means of PRA (PCR Restriction Analysis). DNA was directly extracted from tissue of the lesions and blocked in paraffin. The role of this agent in pet bird infection is discussed, as well as its zoonotic potential.

Hematology of free-living marsh deer (Blastocerus dichotomus) from southeast Brazil.

This work reports basic hematologic values of a sample of a population of free-living marsh deer (Blastocerus dichotomus) living by the Paraná River in Southeast Brazil. Hematologic values are presented separately for male, female, and young animals as well as for anesthetized and nonanesthetized cervids. Nonanesthetized deer restrained by physical means had significantly higher erythrocyte indices and total leukocyte counts. Comparisons of blood parameters of anesthetized animals of different ages and gender differed slightly, with only two significant differences observed: young animals had significantly higher red blood cell counts than adult males and a lower blood total protein content when compared to adult females. Results indicate that two main reference ranges for blood values should be considered for marsh deer, for blood obtained from anesthetized or physically restrained individuals.

The use of singleplex and nested PCR to detect Batrachochytrium dendrobatidis in free-living frogs.

Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlantic Forest. The sample collection area was a protected government park, with no general entrance permitted and no management of the animals there. Swabs were taken from the skin of 107 animals without macroscopic lesions and they were maintained in ethanol p.a. Fungal DNA was extracted and identification of B. dendrobatidis was performed using singleplex and nested-PCR techniques, employing specific primers sequences. B. dendrobatidis was detected in 61/107 (57%) and 18/107 (17%) animals, respectively by nested and singleplex-PCR. Nested-PCR was statistically more sensible than the conventional for the detection of B. dendrobatidis (Chi-square = 37.1; α = 1%) and the agreement between both techniques was considered just fair (Kappa = 0.27). The high prevalence obtained confirms that these fungi occur in free-living frogs from the Brazilian Atlantic Forest with no macroscopic lesions, characterizing the state of asymptomatic carrier. We concluded that the nested-PCR technique, due to its ease of execution and reproducibility, can be recommended as one of the alternatives in epidemiological surveys to detect B. dendrobatidis in healthy free-living frog populations.