Felipe Masiero Salvarani

Protective potential of recombinant non-purified botulinum neurotoxin serotypes C and D

Botulinum neurotoxin (BoNT) serotypes C and D are responsible for cattle botulism, a fatal paralytic disease that results in great economic losses in livestock production. Vaccination is the main approach to prevent cattle botulism. However, production of commercially available vaccines (toxoids) involves high risk and presents variation of BoNT production between batches. Such limitations can be attenuated by the development of novel nontoxic recombinant vaccines through a simple and reproducible process. The aim of this study was to evaluate the protective potential of recombinant non-purified botulinum neurotoxin serotypes C and D. Bivalent vaccines containing 200xa0μg rHCC and rHCD each were formulated in three different ways: (1) purified antigens; (2) recombinant Escherichia coli bacterins; (3) recombinant E.xa0coli cell lysates (supernatant and inclusion bodies). Guinea pigs immunized subcutaneously with recombinant formulations developed a protective immune response against the respective BoNTs as determined by a mouse neutralization bioassay with pooled sera. Purified recombinant antigens were capable of inducing 13xa0IU/mL antitoxin C and 21xa0IU/mL antitoxin D. Similarly, both the recombinant bacterins and the cell lysate formulations were capable of inducing 12xa0IU/mL antitoxin C and 20xa0IU/mL antitoxin D. These values are two times as high as compared to values induced by the commercial toxoid used as control, and two to ten times as high as the minimum amount required by the Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA), respectively. Therefore, we used a practical, industry-friendly, and efficient vaccine production process that resulted in formulations capable of inducing protective immune response (neutralizing antitoxins) against botulism serotypes C and D.

Comparison of the tuberculin test, histopathological examination, and bacterial culture for the diagnosis of tuberculosis (Mycobacterium bovis) in buffaloes (Bubalus bubalis) in Brazil.

Tuberculosis is a disease with a great zoonotic potential. It is considered a major obstacle to cattle production and is responsible for severe losses in several production systems. A comparative cervical test (CCT) was performed in 1140 buffaloes from different mesoregions of the state of Pará, Brazil, with the aim of comparing the sensitivity and specificity of CCT with histopathological examination and bacterial culture. Of the animals tested using CCT, 4.65xa0% (53/1140) were positive, 2.98xa0% (34/1140) were inconclusive, and 92.36xa0% (1053/1140) were negative. Among the 168 sacrificed animals, 33 were positive, 18 were inconclusive, and 117 were negative by CCT, and samples from the sacrificed animals were collected for histopathological examination and bacterial culture. A qualitative evaluation of the tuberculin test was performed by comparing the test results with the histopathological and bacteriological results. The latter two tests yielded a prevalence of 4.16xa0%, a sensitivity of 71.43xa0%, and a specificity of 82.61xa0%. Based on these results, we concluded that CCT yielded satisfactory results and can be applied in diagnostic studies in buffaloes. The prevalence rate obtained using three distinct diagnostic methods suggests that Mycobacterium bovis was present in a few animals in the population evaluated.

Degenerative joint disease in cattle and buffaloes in the Amazon region: a retrospective study

Foi realizado um estudo retrospectivo sobre os aspectos epidemiologicos e clinico-patologicos em bovinos e bufalos com doenca articular degenerativa (DAD) no estado do Para, Brasil. Durante os anos de 1999 a 2014 foram avaliados 11 bovinos e 24 bubalinos. Todos os animais atendidos com suspeita clinica de DAD foram submetidos a exame clinico do sistema locomotor. Foram necropsiados sete bovinos e oito bubalinos com sinais clinicos da enfermidade. Os sinais clinicos comuns observados em ambas as especies foram claudicacao cronica, andar rigido, alteracoes posturais, crepitacoes audiveis no membro acometido, decubito prolongado, dificuldade para levantar, e emagrecimento progressivo. As lesoes articulares evidenciadas na necropsia consistiram em irregularidade da superficie articular, presenca de erosao na cartilagem articular e no tecido osseo subjacente, proliferacao de tecido osseo periarticular com formacao de osteofitos. Tanto nos bovinos como nos bubalinos as articulacoes mais acometidas foram as dos membros posteriores. Nos bubalinos, possivelmente o principal fator predisponente ao surgimento de DAD foi a deficiencia de fosforo, ao contrario dos bovinos, nos quais os defeitos de conformacao anatomica dos membros posteriores, traumas cronicos em virtude da atividade exercida, como a coleta de semen e a idade avancada, foram o que, possivelmente, contribuiram para surgimento da enfermidade.

Infecção transplacentária e intrauterina por Brucella abortus em búfalos (Bubalus bubalis)

The objective of this study was to detect Brucella abortus and injuries caused by the bacteria in fetal membranes and fetuses. Twenty buffaloes serologically positive for brucellosis were used and subjected to stamping for collection of material from the closed uterus of several months gestation. Fetal age was determined by ultrasound examination and the size of fetuses was measured at necropsy. The samples were subjected to histopathology and qPCR. From the second month of pregnancy on it was possible to detect the presence of B. abortus DNA in amniotic fluid, allantoic liquid and uterus, and from the fifth month on in placenta, heart, spleen, kidney, lung, intestine, liver and lymph nodes of the fetuses. The main pathological findings were fibrinous suppurative necrotic placentitis, and chronic endometritis.

Equine infectious anemia on Marajo Island at the mouth of the Amazon river

A anemia infecciosa equina (EIA) e uma importante enfermidade, transmissivel e incuravel causada por um lentivirus, equine infectious anemia virus (EIAV), e nao ha relatos na literatura desta infeccao em equinos da Ilha de Marajo. O objetivo deste estudo foi diagnosticar a anemia infecciosa equina nos municipios de Cachoeira do Arari, Salvaterra, Santa Cruz do Arari e Soure, Ilha de Marajo, no bioma amazonico do estado do Para, Brasil. Para a pesquisa sorologica foram coletadas 294 amostras de animais da especie equina, acima de cinco meses de idade, de ambos os sexos, das racas puruca, marajoara e de mesticos, testadas pela imunodifusao em gel de Agar (IDGA). Foi verificada uma prevalencia de 46.26% (136/294) de casos positivos para EIA. A doenca e considerada endemica nos municipios estudados, tanto pelos aspectos ecologicos da regiao que propiciam a manutencao da populacao de insetos hematofagos vetores, quanto pela ausencia de medidas oficiais de controle da doenca.

Detecção e tratamento de otite por Rhabditis blumi em bovinos da região Norte do Brasil

This study aimed to describe the occurrence of parasitic otitis caused by Rhabditis blumi in dairy cattle of the Gir race from a farm in northern Brazil. Forty-two samples were collected from cattle by swab washed from the external auditory canal (EAC). On clinical examination, in 71.4% (30/42) of the cattle the parasite was found in the cerumen of the ear canal, along with alopecia of head and hump caused by discomfort and itching of the auricular region. At microscopic analysis of material from the conjunctival sac the parasite was found in 90% (9/10) of the evaluated cattle. In addition, 9.5% (4/42) of the cattle showed nervous symptoms, such as mild to moderate rotation of the head, apathy, flaccid lips and unilateral ptosis, change in chewing and food accumulation in the oral cavity. Thirty cattle positive for Rhabditis spp. were randomly divided into three groups of 10 animals each: (G1) Cattle Control, (G2) Cattle treated with ivermectin 1% pour-on, and (G3) Cattle undergoing wash of the external auditory canal (EAC). Each treatment was repeated three times with intervals of seven days. In G1, 10 cattle remained infected throughout the study. In G2, 20% of the cattle were negative after the first two treatments, however were positive at the third evaluation. In G3, all cattle remained positive, but with decrease in parasite load. Identification by molecular analysis of amplified fragments through the expansion D2/D3 28S rDNA confirmed the presence of only Rhabditis blumi. Based on clinical, morphologic and molecular examination, it appears to be the first report of the occurrence of R. blumi infection in Gir cattle in the State of Para, due to the purchase of cattle from areas where parasitic otitis has been diagnosed, as from Minas Gerais, to produce crossbred animals (Gir x Holstein). This emphasizes the importance of prior clinical examination by the veterinary service in order to transfer only healthy animals to other properties or regions. This appears also to be the first report on R. blumi infection of the conjunctival sac in cattle. Treatment with ivermectin in G2 did not produce clinical improvement.

Teores de cobre, zinco e ferro no fígado de búfalos (Bubalus bubalis) com paratuberculose

In order to study copper, zinc and iron concentration in the liver of buffaloes with paratuberculosis (PTB), 13 buffalo cows above three years of age of the Murrah and Mediterranean races or their crosses were used. They originated from two farms in the municipalities of Sao Luis and Sao Mateus, state of Maranhao, Brazil. The animals were selected according to clinical signs of paratuberculosis, as diarrhea, dehydration and submandibular edema. Rectal biopsies for detection of Mycobacterium avium subsp. paratuberculosis (Map) through PCR in real time (qPCR) and Ziehl-Neelsen (ZN) stain were performed on all animals. Seven buffaloes revealed positive and six were negative for PTB. They were separated into two groups: Group 1 contained seven buffaloes positive for paratuberculosis, and Group 2 contained six animals negative for paratuberculosis. They were euthanized and postmortem examination was performed for the collection of various tissue samples to be fixed in 10% formalin for histopathology; also liver tissue samples were collected to be frozen for chemical analysis of trace minerals (Cu, Zn and Fe). Postmortem showed that all buffaloes with PTB had brown colored mesenteric lymphnodes, indicating hemosiderosis. One buffalo had brown spots on the mucosa of the small intestine. Histopathology revealed moderate to severe hemosiderosis of the spleen in buffaloes of Group 1. All animals positive for PTB showed micromineral levels below the reference values. The average Cu concentration in buffaloes with PTB was only 18.0ppm and the one of Zn only 68.6ppm. In Group 2, negative for PTB, the average Cu concentration was 113.7ppm and the one of Zn 110.0ppm. Fe concentrations in buffaloes of both groups were high (>669ppm). The analysis of trace elements in the liver confirmed copper deficiency, but also showed low levels of zinc and high levels of iron. Based on clinical and pathological findings, and the micromineral concentrations found in the liver, it is concluded that paratuberculosis could lead to mineral deficiency and worsen the clinical condition of the buffaloes.

Lead poisoning in cattle and chickens in the state of Pará, Brazil

The present study describes the occurrence of lead poisoning in cattle and chickens in Para, Brazil. In a lot composed of 80 calves from a dairy herd, 10 animals became sick and nine died, but one animal recovered after being removed from the paddock. Upon inspection of this paddock, the presence of truck batteries used to store energy captured by solar panels was found. The clinical signs observed in calves included difficult breathing, nasal discharge, excessive salivation, corneal opacity, pushing of the head against objects and recumbency. The chickens had decreased oviposition and produced eggs with thin or malformed shells. The necropsy findings of the cattle, as well as the histopathological changes observed, were of little significance except for one animal that showed mild astrocytosis histopathology in the cerebral cortex. In one of the chickens, renal histopathology showed mild multifocal acute tubular necrosis. The mean lead concentrations in the livers and kidneys of the cattle were 93.91mg/kg and 209.76mg/kg, respectively, and the mean concentration detected in chicken livers was 105.02mg/kg. It was concluded that the source of lead poisoning in these calves and chickens were the truck battery plates, which were within reach of the animals.