Free-living capybaras (Hydrochoerus hydrochaeris) in an urban area in Brazil: biochemical and hematological parameters

Capybaras have found favorable conditions for survival and reproduction in green urban environments. In recent years, the population of these large rodents has been increasingly abundant in several brazilian cities such as Uberlândia, a municipality of the southeastern region with a Cerrado biome. Capybaras are important in the Brazilian Spotted Fever epidemiological chain, by amplifying infection rates of the vector population. However, knowledge of this host's physiology is scarce. Thus, the aim of this work was to describe hematological and biochemical parameters of free-living capybaras groups in urbanized areas in the city of Uberlândia, Minas Gerais State, Brazil. Capybaras were captured in 4 different locations of Uberlândia city, Minas Gerais state, including 1 Condominium (P1), 1 Private Market Garden (P2), 1 Private Club (P3) and 1 Municipal Park (P4). The animals were baited into an octagonal iron corral and chemically contained with anesthetic darts. After sedated, blood was collected from the femoral vein in tubes with and without EDTA. Biochemical evaluation, hematological analysis with differential leukocyte counts and search for Dirofilaria sp. were done. The blood count and biochemistry values obtained from animals of different ages, sex and sectors (P1, P2, P3 and P4) were submitted to the Shapiro-Wilk normality test, considering 95% significance. Values that had a normal distribution were subjected to ANOVA tests followed by Student's t-test. Values that did not follow normality were submitted to the Kruskal-Wallis test, to obtain a P-value, with a significance level of 95%. A total of 19 capybaras were captured: 4 in P1, 6 in P2, 4 in P3 and 5 in P4. From the 19 animals, 13 were females (68.42%) and 6 were males (31.57%), 12 adults (63.15%) and 7 juveniles (36.84%). Apart from occasional skin scars and moderate to intense Ambyomma spp. tick infestations, all captured animals were healthy on a broad examination. From 5 animals captured in P4, despite the use of anticoagulant, blood from 4 animals clotted fast. No microfilariae were found in the thick drop test in any of the 19 animals sampled, and in 2 adult female capybaras captured in P1, Kurloff cells were observed. Hematological and biochemical values presented no major differences when comparing sex and age. Nevertheless, differences in liver and kidney profile were observed between the capybara groups, including ALT, alkaline phosphorus, BUN and creatinine. Blood from 4 animals clotted fast, despite the use of EDTA tubes. Blood clotting of samples with anticoagulant in this work could be associated with some physiological features inherent to capybaras. Many attempts were required to obtain enough blood from each individual due to the rapid hemostasis, what come in accordance with reports in literature. Kurloff cells were observed in 2 adult female capybaras captured in P1, which can be found in peripheral blood of female rodents during follicular phase of estrous cycle. Hematological and biochemical values differences in liver enzymes such as ALT and alkaline phosphorus, and kidney profile enzymes including BUN and creatinine could be associated to capture stress or dietetic variation between groups. Despite statistical relevant, the values were still in accordance with other works, although comparisons should be done with caution since various environments exert a diverse array of stimulus upon the animals such as parasitic, infective, stress, nutritional, social and undoubtedly blood parameters mirror them. In conclusion, this work contributes to the standardization of free-living capybaras' physiological parameters in urban areas.(AU)

Microorganisms contaminating ticks collected at natural reserves or wild animals / Microrganismos contaminantes de carrapatos coletados em reservas naturais ou animais selvagens

This work investigated microorganisms responsible for the contamination and death of ticks from natural reserves and wild animals and later kept in the Laboratory of Ixodology in the Veterinary School of the Federal University of Uberlândia. Such investigation aimed prevention of tick death in the laboratory but also search for microorganisms to be used in the biological control of ticks. From four tick samples of Amblyomma genus, the following agents were isolated: Staphylococus sp, Gram positive bacillus, filamentous fungi of the genera Aspergillus and Penicillium, and a yeast identified as Non-albicans Candida and Cryptococcus sp. Even though the source of contamination of these ticks is uncertain, this study displayed the necessity of to better evaluating the spread of pathogens by ticks, as well as those known to be transmitted solely during tick feeding.

Neste trabalho foram investigados microrganismos responsáveis pela colonização e morte de carrapatos provenientes de reservas naturais ou animais selvagens e mantidos posteriormente no Laboratório de Ixodologia da Faculdade de Medicina Veterinária da Universidade Federal de Uberlândia. Esta investigação se fez necessária para tentar prevenir mortalidade de carrapatos no laboratório, mas também para contribuir com a busca por microrganismos que poderiam ser utilizados no controle biológico do ácaro. Foram isolados de cinco amostras de carrapatos do gênero Amblyomma os seguintes microrganismos: Staphylococus sp, bacilos Gram positivos, fungos filamentosos dos gêneros Aspergillus e Penicillium, além de leveduras identificadas como Candida não-albicans e Cryptococcus sp. Mesmo que a origem da contaminação dos carrapatos com estes microrganismos seja incerta este trabalho indica a necessidade de se avaliar melhor a difusão de outros patógenos por carrapatos, além daqueles transmitidos com a hematofagia.

Ticks on birds in a savanna (Cerrado) reserve on the outskirts of Uberlândia, Minas Gerais, Brazil / Carrapatos em aves de uma reserva do Cerrado na periferia de Uberlândia, Minas Gerais, Brasil

We report tick infestations on birds, in the environment and on domestic animals in a non-forested phytophysiognomy, the savanna-like Cerrado sensu stricto, in a natural reserve on the outskirts of the urban area of Uberlândia, Minas Gerais, Brazil. Overall, 238 birds within 50 species, 15 families and six orders were caught. Passeriformes were the most numerous, with 216 birds (90.75%), among which 22 had ticks (n = 31). Within this order, the prevalence of tick infestation was 10.2%, and the abundance and mean intensity were 0.14 and 1.41, respectively. Only immature ticks of the species Amblyomma nodosum were found on the birds. The tick species found both on animals (Rhipicephalus sanguineus, Rhipicephalus (Boophilus) microplus, Amblyomma cajennense and Dermacentor nitens) and in the environment (Amblyomma dubitatum, Rhipicephalus (B.) microplus and Amblyomma cajennense) were as expected. This difference in tick species between the environment and birds possibly occurred because the sampling of the environment was limited to the ground. This study also highlights the importance of the diverse microenvironments used by ticks and hosts in the same area and the complex ecology of bird-tick relationships. Ecological and epidemiological aspects of the findings are discussed.

Nesse trabalho relatam-se infestações de carrapatos em aves, meio ambiente e em animais domésticos em uma fitofisionomia não florestal, o Cerrado stricto sensu, de uma reserva natural na periferia da área urbana de Uberlândia, Minas Gerais, Brasil. Para tal, 238 aves de 50 espécies foram capturadas, pertencentes a 15 famílias e seis ordens. Passeriforme foi a mais numerosa, com 216 indivíduos (90,75%), dos quais 22 estavam parasitados com 31 carrapatos. Nos Passeriformes a prevalência de infestação de carrapatos foi de 10,2%, a abundância e intensidade média foi de 0,14 e 1,41, respectivamente. Apenas carrapatos imaturos da espécie Amblyomma nodosum foram encontrados em aves. As espécies de carrapatos encontradas tanto em animais (Rhipicephalus sanguineus, Rhipicephalus (Boophilus) microplus, Amblyomma cajennense, Dermacentor nitens) como no ambiente (Amblyomma dubitatum, Rhipicephalus (B.) microplus, Amblyomma cajennense) foram aquelas já esperadas. Esta diferença de espécies de carrapatos entre ambiente e de aves possivelmente ocorreu porque a amostragem do ambiente se restringiu ao solo. Esse estudo também destaca a importância dos diversos microambientes usados por carrapatos e hospedeiros em uma mesma área e a complexa ecologia das relações ave-carrapato. Aspectos ecológicos e epidemiológicos dos achados são discutidos.