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.

A Survey of Diseases in Different Species of Wild, Captive, and Illegally Traded Birds in Brazil

Native and exotic avian species can act as reservoirs of pathogens, including bacteria and viruses, with conservation and public health implications. A retrospective study on the diagnosis and frequency of diseases in wild and exotic avian species was conducted. The occurrence of particular diseases was associated with the type of captivity or the bird's origin. The investigation included macroscopic and microscopic descriptions and the molecular determination of the causative agent(s). Additional immunohistochemical (IHC) analysis, PCR, and genetic sequencing were conducted. A total of 243 cases were compiled for the study, mainly consisting of native wild species (39.1%) obtained from illegal trade. Primary infectious diseases, mainly parasitic (18.1%) and viral (17.7%), were the most common, although coinfections were substantial (18.1%) in birds rescued from trafficking. Fractures and neoplasms accounted for 3.7% and 3.3% of the cases, respectively. Parasitic and viral diseases were the most common in both exotic and wild birds. Chlamydia psittaci, a lethal and zoonotic bacterium, was an important cause of death, especially in native Psittaciformes. The recent detection of Psittacid alphaherpesvirus 5 (PsAHV 5) in exotic psittacines and the diagnosis of coinfections in trafficked birds highlight the importance of monitoring avian health to control potential pathogens that may endanger conservation efforts.

Acute, fatal Sarcocystis falcatula infection in rose-ringed parakeets (Psittacula krameri)

Sarcocystosis is an important avian disease that affects several intermediate host species. Birds not endemic from Americas, like Old World psittacine species, appear to be more susceptible to lethal infection than New World psittacine species. The aim of this study was to investigate the sudden death of rose-ringed parakeets (Psittacula krameri) in an exotic private parrot's aviary. Macroscopically, the most prevalent findings were severe lung congestion, slight superficial myocardial hemorrhagic lesions, enlarged liver and congestion of meningeal vessels. The initial diagnosis of sarcocystosis was made in all birds by microscopic observations of intravascular pulmonary schizonts, as well hepatitis, myocarditis, and nephritis. Immunohistochemistry for detection of Sarcocystis sp. antigen revealed an intense immunoreactivity in the lungs. Molecular identification of Sarcocystis falcatula were obtained by nested PCR and sequencing of amplified fragments of internal transcribed spacer 1 (ITS1) and three surface antigen-coding genes (SAG2, SAG3 and SAG4). SAG-based phylogenies showed a close relatedness of the isolate described here and S. falcatula previously detected in naturally infected native birds, which suggests that the isolates that affected ringnecks are a common isolate that circulates in Brazil.

DISTRIBUTION AND ANTIMICROBIAL RESISTANCE OF STAPHYLOCOCCI ISOLATED FROM FREE-LIVING SOUTH AMERICAN COATI (NASUA NASUA) IN AN URBAN PARK IN MINAS GERAIS, BRAZIL

The scientific information regarding staphylococci in procyonids is scarce. Hence, the aim of this study was to evaluate the frequency, distribution, and pattern of antimicrobial resistance of staphylococcal species isolated from free-roaming coatis (Nasua nasua) in an urban park in Belo Horizonte, Minas Gerais, Brazil. Rectal swabs from 55 free-living coatis were plated onto mannitol salt agar for isolating staphylococci, and species were identified using matrix-assisted laser desorption/ionization-time of flight mass spectrometry, polymerase chain reaction (PCR) of nuc, and sequencing of 16S rRNA and rpoB when needed. Antimicrobial susceptibility was investigated using the disk diffusion method, and the presence of the mecA gene was investigated by PCR. A total of 72.7% of the animals tested positive for staphylococci. Nine different species were identified, and Staphylococcus intermedius (60.4%) and S. delphini (20.9%) were the most frequently isolated species. Most of the isolates were susceptible to most of the antimicrobials evaluated, with a resistance pattern seen for penicillin (13.9%). One isolate was multidrug-resistant (MDR). The present study suggests that coatis are natural hosts of S. intermedius and S. delphini and, despite living in a heavily anthropized environment, the Staphylococcus spp. isolates showed a low incidence of drug resistance.

ANTIMICROBIAL SUSCEPTIBILITY OF STAPHYLOCOCCUS SPP. ISOLATED FROM FELIDS AND CANIDS IN BELO HORIZONTE ZOO, BRAZIL

The epidemiology of Staphylococcus spp. has become a major concern among humans and animals due to increasing antimicrobial resistance and frequent reports of infection. Despite the importance of animals as reservoirs for staphylococci, little is known about the epidemiology of Staphylococcus spp. in most nondomestic species, including canids and felids. This study evaluated the frequency, distribution, and patterns of antimicrobial resistance of staphylococcal species isolated from captive felids and canids from Belo Horizonte Zoo, Brazil. Rectal, oral, and nasal swabs from apparently healthy maned wolves (Chrysocyon brachyurus, n= 7), a lion (Panthera leo, n = 1), jaguars (Panthera onca, n = 3), and one swab of a cougar (Puma concolor) with an ear infection were streaked onto mannitol salt agar. Colonies identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry, polymerase chain reaction for the Staphylococcus intermedius group (SIG), and 16S rRNA gene sequencing. Isolates were subjected to antimicrobial susceptibility tests and Staphylococcus pseudintermedius strains were subjected to multilocus sequence typing. Staphylococcus species were isolated from 24 of the 34 samples (70.6%). Among the isolated strains, S. pseudintermedius and Staphylococcus felis were the most frequent species (41.7 and 25%, respectively). Five novel sequence types were identified among the S. pseudintermedius isolates. Resistance to tetracycline (7/24, 29.2%) or penicillin (6/23, 26.1%) was significantly higher than the other antimicrobial agents tested (P < 0.05). One isolate, Staphylococcus nepalensis, was positive for mecA and resistant to five antimicrobials, and was thus classified as multidrug-resistant. The present work suggests that maned wolves are natural hosts of SIG and also reports the isolation of S. felis in sick and healthy, captive, nondomestic carnivores. The isolated staphylococci were susceptible to most classes of antimicrobials tested. However, the multidrug-resistance capability of an S. nepalensis strain reinforces the hypothesis that felids and canids act as reservoirs of pathogens with antimicrobial resistance.

SARS-CoV-2 Spillback to Wild Coatis in Sylvatic-Urban Hotspot, Brazil

We tested coatis (Nasua nasua) living in an urban park near a densely populated area of Brazil and found natural SARS-CoV-2 Zeta variant infections by using quantitative reverse transcription PCR, genomic sequencing, and serologic surveillance. We recommend a One Health strategy to improve surveillance of and response to COVID-19.

Polyarteritis nodosa in a captive common wooly monkey (Lagothrix lagotricha) associated with intestinal necrosis, peritonitis, and sepsis

Polyarteritis nodosa is an idiopathic necrotizing vasculitis that affects small to medium-sized arteries. We describe a case of polyarteritis nodosa in a captive common wooly monkey (Lagothrix lagotricha) associated with transmural intestinal necrosis and secondary peritonitis. This condition must be considered for differential diagnosis of segmental arteritis in neotropical primates.

Genotyping of Toxoplasma gondii in a lethal toxoplasmosis outbreak affecting captive howler monkeys (Alouatta sp.)

BACKGROUND

Toxoplasmosis is a zoonotic disease that affects humans and warm-blooded animals. This study describes an outbreak of toxoplasmosis in howler monkeys (Alouatta sp.) and survival of capuchins (Sapajus apella), under the same environmental conditions.

METHODS

Howler monkeys were submitted to post-mortem examination. Tissue samples were processed to histopathology and immunohistochemistry to detect lesions and tachyzoites of Toxoplasma gondii. Tissue samples were also frozen and submitted to PCR and genotyping of T. gondii.

RESULTS

Typical lesions were observed in several organs including the liver, lymph node, and brain, with intralesional cysts and tachyzoites of T. gondii demonstrated by immunohistochemistry. T. gondii genomic sequences were amplified by PCR, and genotyping characterized the same T. gondii clone in all howler monkeys.

CONCLUSIONS

Our results support the notion that some species of neotropical primates are highly susceptible to toxoplasmosis and the hypothesis that capuchins (S. apella) may be resistant.

Histology of the gastrointestinal tract from Bothrops jararaca and Crotalus durissus

Na atualidade, a importância das serpentes extravasa a conotação em saúde pública (acidentes ofídicos), e pesquisas promissoras têm demonstrado a utilidade dos venenos das serpentes em diversas áreas como oncologia, diagnóstico, terapia anticoagulante e tratamento da dor. Ainda assim, existem lacunas no conhecimento básico sobre esses animais, tais como a caracterização histológica do seu sistema gastrointestinal, que se tornam obstáculos para estudos nos campos da histologia e patologia comparadas. Nesse contexto, o presente trabalho pretende contribuir com o avanço do conhecimento sobre histologia de serpentes a partir da descrição e análise histológica de amostras do trato gastrointestinal de exemplares das espécies Bothrops jararaca e Crotalus durissus. Para tanto, foram coletadas amostras de 12 indivíduos com até seis meses de idade, seis por espécie (distribuídos igualmente entre machos e fêmeas). A partir dos órgãos colhidos, lâminas histológicas foram preparadas e coradas pela técnica de hematoxilina e eosina, bem como PAS com Alcian Blue. As lâminas foram fotografadas por câmera de alta resolução, resultando em um portfólio representativo da histologia do sistema gastrointestinal desses animais.

Antimicrobial photodynamic therapy for infectious stomatitis in snakes: Clinical views and microbiological findings

BACKGROUND

Antimicrobial photodynamic therapy (APDT) has been broadly investigated as an alternative to treat localized infections, without leading to the selection of resistant microorganisms. Infectious stomatitis is a multifactorial disease frequently reported in captive snakes characterized by infection of the oral mucosa and surrounding tissues. In this study, we investigated methylene blue (MB)-mediated APDT to treat infectious stomatitis in snakes and verified the resistance phenotype and genotype before and after APDT.

METHODS

Three Boid snakes presented petechiae, edema and caseous material in their oral cavities. MB (0.01%) was applied on the lesions and after 5min they were irradiated using a red laser (λ=660nm), fluence of 280J/cm², 8J and 80s per point, 100mW, spot size 0.028cm² and fluence rate of 3.5W/cm². APDT was repeated once a week during 3 months. Samples of the lesions were collected to identify bacteria and antibiotic resistance profiles. To analyze the clonality of bacterial isolates before and after APDT, isolates were subjected to ERIC PCR analysis.

RESULTS

Snakes presented clinical improvement such as reduction of inflammatory signs and caseous material. Pseudomonas aeruginosa and Escherichia coli were present in all snakes; Klebsiella pneumoniae and Morganella morganii were also identified in some animals. We also observed that the oral microbiota was completely replaced following APDT. However, K. pneumoniae isolates before and after APDT were a single clone with 100% of genetic similarity that lost resistance phenotype for seven antibiotics of four classes.

CONCLUSIONS

These results show that APDT can be used to treat infectious stomatitis in snakes.

Functional characterization of neotropical snakes peripheral blood leukocytes subsets: Linking flow cytometry cell features, microscopy images and serum corticosterone levels

Reptiles are the unique ectothermic amniotes, providing the key link between ectothermic anamniotes fish and amphibians, and endothermic birds and mammals; becoming an important group to study with the aim of providing significant knowledge into the evolutionary history of vertebrate immunity. Classification systems for reptiles' leukocytes have been described by their appearance rather than function, being still inconsistent. With the advent of modern techniques and the establishment of analytical protocols for snakes' blood by flow cytometry, we bring a qualitative and quantitative assessment of innate activities presented by snakes' peripheral blood leukocytes, thereby linking flow cytometric features with fluorescent and light microscopy images. Moreover, since corticosterone is an important immunomodulator in reptiles, hormone levels of all blood samples were measured. We provide novel and additional information which should contribute to better understanding of the development of the immune system of reptiles and vertebrates.

Histological analysis of the eyeball of Neotropical birds of prey Caracara plancus, Falco sparverius, Rupornis magnirostris, Megascops choliba and Athene cunicularia

Nos últimos anos a oftalmologia aviária se tornou um instrumento de grande relevância para a conservação de aves de vida livre e de cativeiro, principalmente pela crescente utilização do exame oftalmológico para a triagem de indivíduos designados para reintrodução em ambientes naturais. Os olhos das aves de rapina são estruturas imprescindíveis para detectar e capturar suas presas, e a sua notável capacidade visual torna o seu sistema de visão assunto de grande interesse para o estudo anatômico e histológico. Neste contexto, no presente trabalho foi realizada a análise histológica do bulbo ocular de aves de rapina representadas por espécies pertencentes às ordens Falconiformes, Accipitriformes e Strigiformes presentes em território brasileiro. Para realização do estudo foram utilizados vinte bulbos oculares obtidos de animais mortos por causas naturais, das espécies Caracara plancus, Falco sparverius, Rupornis magnirostris, Megascops choliba e Athene cunicularia.. As lâminas histológicas foram coradas pela técnica de hematoxilina e eosina e, analisadas por microscopia óptica. Foi constatada a existência de um padrão histológico com discreta variação entre as estruturas oculares nas diferentes espécies avaliadas, com destaque para o cristalino e a retina. Este estudo salienta a importância da determinação do padrão histológico ocular das espécies, e seus resultados atribuem informações histológicas basais auxiliares na determinação de diagnósticos histopatológicos oculares.