Matheus Dias Cordeiro

Trypanosoma rhipicephalis sp. nov. (Protozoa: Kinetoplastida) isolated from Rhipicephalus microplus (Acari: Ixodidae) ticks in Rio de Janeiro, Brazil

Parasites of the genus Trypanosoma are microorganisms that display wide morphological, biological and genetic variability. Here we present the first description of an isolate of the genus Trypanosoma naturally infecting the tick Amblyomma brasiliense. The ticks were collected from a specimen of Tayassu pecari (Queixada, white-lipped peccary) from the Itatiaia National Park, Itatiaia, Rio de Janeiro, Brazil. The isolate was characterised by molecular, morphometric and biological analyses. A Trypanosoma culture was isolated from crushed nymphal and adult ticks, propagated in the tick cell line IDE8 and maintained in L15B culture medium, incubated at 32 °C. The isolate grew well in L15B medium at 30 °C, 32 °C and 34 °C but not at lower or higher temperatures. The culture remained stable in axenic L15B medium at 30 °C. Cryopreserved cultures retained viability after cryopreservation in liquid nitrogen. Growth in axenic medium and developmental forms of the trypanosomes were analysed. Analysis of the 18S rDNA region confirmed the authenticity of this new species and the nucleotide sequence was deposited in Genbank. The species was named Trypanosoma amblyommi sp. nov. strain C1RJ. Characteristics related to pathogenicity, involvement with vertebrate hosts, epidemiology, developmental cycle and transmission mechanisms are still unknown. Therefore, further studies are necessary to understand aspects of the biological cycle of Trypanosoma amblyommi sp. nov.

Epidemiological investigation of Borrelia burgdorferi in horses in the municipality of Sinop—MT, Brazil

Borrelia burgdorferi sensu stricto is the main etiological agent of Lyme disease (LD) in the USA. In Brazil, it is believed that a similar spirochete is the causal agent of the Baggio–Yoshinari syndrome (BYS), a zoonosis also transmitted by ticks, whose clinical manifestations are similar to those of LD. Despite the epidemiological importance, there are no studies reporting the presence and the prevalence of B. burgdorferi among horses in Mato Grosso State. The aim of this study was to detect and measure the frequency of IgG antibodies anti-B. burgdorferi American strain G39/40 in horses in the municipality of Sinop, MT—Brazil, using the indirect enzyme-linked immunosorbent assay (ELISA) for serological diagnosis. Blood samples from 367 horses were collected in 81 farms. An epidemiological questionnaire was applied during the visits to obtain information related to the animals and the farms. From the 367 horses, 214 were positive for B. burgdorferi sensu stricto according to the results of the ELISA test, representing an apparent prevalence of 54.04% [CI = 0.4548051–0.6237234]. Concomitantly, 89 blood samples were taken for molecular analysis by nested polymerase chain reaction (PCR). According to the PCR test results, none of the samples were reactive, although 53 of these samples were reactive according to ELISA. Seventy five farms (92.59%) had at least one reactive horse for B. burgdorferi. Our results support the hypothesis of the presence of anti-Borrelia spp. antibodies in horses in Mato Grosso, reaching a high animal prevalence. Besides that, leisure/sport purposes proved to be a risk factor, with an odds ratio of 3.16. These findings clearly indicate the need of borreliosis control in Sinop and make a significant contribution to the knowledge of the disease in Mato Grosso.

Experimental infection of Rickettsia parkeri in the Rhipicephalus microplus tick

This study aimed to evaluate, by means of artificial feeding, the interaction between a pathogenic rickettsia and the hard tick R. microplus. We used partially engorged females fed on calves free of Rickettsia spp. Group 1 (G1), containing 20 ticks, was fed bovine blood only. Group 2 (G2), containing 20 ticks, was fed blood containing uninfected VERO cells, and group 3 (G3), containing 40 ticks, was fed blood containing VERO cells infected with Rickettsia parkeri. Biological parameters of the non-parasitic phase and a possible bacterial transmission to the tick eggs and to guinea pigs were evaluated. At the end of oviposition, all G3 females were PCR-positive for genes specific for the genus Rickettsia. Although no guinea pigs were infected, the experimental infection of R. microplus by R. parkeri caused a deleterious effect on the oviposition and provided the first report of transovarian transmission of rickettsia in this tick.

Alterações bioquímicas, anatômicas e histopatológicas em fígado de Gallus gallus Linnaeus, 1758 experimentalmente infectados por Borrelia anserina Sakharoff, 1891

A espiroquetose aviaria e uma enfermidade septicemica de curso agudo, cosmopolita, que acomete diversas especies aviarias, causada por Borrelia anserina e transmitida pelo carrapato Argas miniatus. O experimento teve como objetivos avaliar as alteracoes bioquimicas e anatomo-histopatologicas no figado de Gallus gallus, causadas pela infeccao experimental por B. anserina. Quarenta aves da especie G. gallus foram divididas em quatro grupos inteiramente casualizados com 10 animais cada: G1 - inoculado com soro infectado com B. anserina; G2 - inoculado com soro fisiologico a 0,9%; G3 - exposto a ninfas de terceiro instar de A. miniatus infectados por B. anserina; G4 - exposto a ninfas de terceiro instar de A. miniatus livres de B. anserina. As aves dos Grupos 1 e 3 manifestaram no 3o e 6o dias pos-inoculacao (DPI) respectivamente, sintomatologia caracteristica da doenca como inapetencia, perda de peso, sonolencia, diarreia esverdeada, mucosas hipocoradas, penas arrepiadas e hipertermia. Os niveis de ALT do Grupo 1 mostraram-se significativamente mais elevados apenas no 12oDPI e 24oDPI em relacao ao seu grupo controle (Grupo 2) e no Grupo 3 esses niveis se mantiveram elevados ate o 20o DPI em comparacao ao seu grupo controle (Grupo 4). Os niveis da enzima AST pouco oscilaram nos grupos experimentais, embora tenham sido encontradas elevacoes no 12oDPI nos Grupos 1 e 3. Os figados das aves dos Grupos 1 e 3 apresentaram a necropsia, moderada hepatomegalia, congestao, superficie irregular e coloracao vermelha a cianotica; constataram-se ainda pequenos pontos esbranquicados na superficie. A histopatologia do figado revelou congestao, infiltrados inflamatorios mononucleares, focos de necrose fibrinoide, dilatacao dos sinusoides e vacuolizacao de hepatocitos. A coloracao de Warthin-Starry revelou, nos figados das aves dos Grupos 1 e 3, a presenca de espiroquetas compativeis com B. anserina, frequentemente no interior de vasos sanguineos.

Padronização de técnica manual para obtenção de plasma rico em plaquetas de bovino

For standardization of manual technique to obtain autologous platelet-rich plasma (PRP) in cattle with reduced cost (manual method) and good quality (ability to concentrate platelets, high level of growth factors and reduced contamination with leukocytes and erythrocytes), that may be used as a modulating agent of the immune response of cows chronically infected with various diseases, 450ml of whole blood from nine clinically and hematologically healthy cattle were collected in CPDA-1 bags and processed within four hours after collection. The blood was divided in aliquots to evaluate 8 protocols (P) of double centrifugation which varied as the speed and time of centrifugation. Platelet, erythrocytes and leukocytes counts in PRP were performed by manual method in a Neubauer chamber. The highest concentration of platelets was obtained in P5 (400g and 800g both for 10 min), followed by (p>0.05) P3 (120g e 473g ambos durante 10 min), P4 (300g e 640g durante 10 min cada), P6 (640g durante 10 min e 640g durante 5 min), P8 (640g durante 5 min e 120g durante 10 min) and P7 (720g and 720g both for 5 min) and different (p <0.05) than the protocols that had lower rates at P1 (120g to 240g, both for 5 minutes) and P2 (both 120g and 473g for 5 min). As for erythrocytes, P8, P7, P6, P5, P4 showed lower concentrations with higher values (p <0.05) observed in P3 and P2. Lesser values of leukocytes were found in P5, P6, P7 and P8 with the biggest value (p <0.05) obtained in P2. All protocols (P1 to P8) were efficient to concentrate platelets and the lowest value (3.65±0.79) was found in P1. Regarding TGF-β1, the P1 and P8 protocols demonstrated the highest values. According to results, P5 and P8 protocols showed the best results for production of PRP in bovine.