Bovine anaplasmosis as a risk factor for retained placenta, mastitis, and abomasal displacement in dairy cattle.

This study aimed to evaluate the frequency of IgG antibodies against A. marginale, the occurrence of this bacterium by qPCR, and the effect of bovine anaplasmosis as a risk factor for clinical cases of retained placenta, mastitis, and abomasal displacement in dairy cattle. For that 179 Holstein cows out of three dairy herds, in the municipality of Sertão, Rio Grande do Sul, Brazil. These cows were on farms that were vulnerable to risk factors that are crucial to susceptibility among these animals to this intracellular hemoparasite. The mean seropositivity for A. marginale from the periods evaluated was 54% on farm A, 69.4% on farm B, and 27.3% on farm C. Molecular diagnosis was performed with qPCR and the mean positivity for A. marginale among the cows on farms A, B, and C in December 2017 was 34.6% (67/179). Infected animals showed clinical cases of retained placenta (6.1%), mastitis (6.1%), and abomasal displacement (0.5%). The association between positivity for anaplasmosis and these clinical cases was assessed through the odds ratio. Our results show that females with a positive qPCR assay for A. marginale had 52.48 times increased probability (OR) to develop clinical cases of retained placenta and mastitis (P < 0.001). These clinical cases negatively impact the productivity of positive females. Thus, implementing preventive and prophylactic control measures to ensure the sanitary quality of the herds is needed to avoid losses due to morbidity and mortality and diminish the economic losses suffered by farmers.

Molecular diagnosis of abdominal angiostrongyliasis by PCR using serum samples.

Abdominal angiostrongyliasis (AA) is a zoonotic disease caused by the nematode Angiostrongylus costaricensis, which is endemic in southern Brazil. Humans become infected by ingesting third-stage (L3) larvae and are considered accidental hosts since neither eggs nor first-stage (L1) larvae are found in feces. The definitive diagnosis can be made by histopathologic examination of surgical specimens or intestinal biopsies. The present study assessed the use of PCR to carry out the molecular detection of AA from serum samples. A total of 62 human serum samples were divided into three groups: (i) 28 serum samples from human patients with presumptive histopathological diagnosis of AA; (ii) 23 serum samples from individuals with unknown serology for AA; (iii) 11 serum samples from patients that suffered from different parasitosis were included. The serum samples were initially tested by in-house indirect ELISA and then by PCR. A total of 14 samples were positive by ELISA, and 6 were positive by PCR. Six samples that were negative by ELISA were positive by PCR. Amplicons were sequenced, and Angiostrongylus DNA was confirmed. We conclude that PCR amplification can be used to confirm Angiostrongylus DNA in serum, which is especially important in cases where antibody levels are too low to be detected. It may also serve as a useful target for survey studies.

Chemoprophylaxis for babesiosis and anaplasmosis in cattle: case report.

Cattle tick fever (CTF) causes significant economic losses in the livestock sector. The pathogenic action of the hemoparasites is associated with anemia, weight loss, abortion and reduced productivity, which result with animal death. Programs to prevent CTF involve several procedures, including immunization, chemoprophylaxis and use of ectoparasiticides, together with the vector control in the environment. The objective of this study was to report an acute outbreak of CTF in a group of 157 Hereford cattle from a farm without presence of the vector, that were moved to a farm in the same state with a high tick infestation (Rhipicephalus microplus). On the day before the transportation, the animals received a chemoprophylaxis with imidocarb dipropionate (3 mg/kg, SC), which was repeated 21 days after the first application. After 42 days, some animals showed signs compatible with CTF, which was confirmed through clinical examination, necropsy, histopathological and hemoparasitological analyses. The morbidity rate was 37.6% and the mortality rate was 24.8%. Calves that were recently weaned were the group most affected with the tick fever, morbidity (100% and mortality (73%). Chemoprophylaxis in association with use of ectoparasiticides was not sufficient to control the outbreak of the disease.

Synthetic gene as target to assess the sensitivity of PCR to detect Trichinella spp. larvae in meat from a non-endemic region.

Trichinellosis is a zoonotic disease exotic in Brazil but commonly found worldwide including South American countries like Argentina. International trading of swine meat needs an official Trichinella-free diagnosis commonly carried out by pepsin-HCl digestion of diaphragm tissue fragments followed by microscopic examination for the presence or absence of Trichinella larvae. The easiness of this diagnostic method allows it to be performed at slaughtering plants but, in contrast, it lacks sensitivity and does not allow species differentiation, which is fundamental for determining geographical and species distribution of different genotypes. In our study, we aimed to evaluate a highly sensitive diagnostic method based on the polymerase chain reaction (PCR) that would allow us to detect and classify different species of Trichinella. Thus, we designed a synthetic gene and selected five sets of primers targeting specific regions of the Trichinella genome. The synthetic gene was cloned into a plasmid and then used to optimize PCR conditions. Using our PCR, we were able to detect 0.001 pg of the synthetic gene, which corresponded to 0.01 larvae. Then, we collected 175 samples of Suidae (domestic and wild boars) diaphragm fragments that were pooled into groups, digested with pepsin-HCl, and had the DNA extracted for analysis by PCR. The clinical samples evaluated were negative by PCR. Our results indicate that the PCR-based method might be a useful diagnostic method complementary to the pepsin-HCl digestion method currently in use, mostly in non-endemic areas.

Chemoprophylaxis for babesiosis and anaplasmosis in cattle: case report / Quimioprofilaxia para babesiose e anaplasmose em bovinos: relato de caso

Abstract Cattle tick fever (CTF) causes significant economic losses in the livestock sector. The pathogenic action of the hemoparasites is associated with anemia, weight loss, abortion and reduced productivity, which result with animal death. Programs to prevent CTF involve several procedures, including immunization, chemoprophylaxis and use of ectoparasiticides, together with the vector control in the environment. The objective of this study was to report an acute outbreak of CTF in a group of 157 Hereford cattle from a farm without presence of the vector, that were moved to a farm in the same state with a high tick infestation (Rhipicephalus microplus). On the day before the transportation, the animals received a chemoprophylaxis with imidocarb dipropionate (3 mg/kg, SC), which was repeated 21 days after the first application. After 42 days, some animals showed signs compatible with CTF, which was confirmed through clinical examination, necropsy, histopathological and hemoparasitological analyses. The morbidity rate was 37.6% and the mortality rate was 24.8%. Calves that were recently weaned were the group most affected with the tick fever, morbidity (100% and mortality (73%). Chemoprophylaxis in association with use of ectoparasiticides was not sufficient to control the outbreak of the disease.

Resumo A "tristeza parasitária bovina" (TPB) gera importantes perdas econômicas na bovinocultura mundial. A ação patogênica dos hemoparasitas resulta em anemia, perda de peso, abortos e diminuição da produtividade, culminando, muitas vezes, em óbito dos animais. Um programa de prevenção para TPB necessita de medidas integradas, como a imunização, quimioprofilaxia e utilização de ectoparasiticidas, em conjunto com ações que visem ao controle ambiental dos vetores. Este artigo tem em vista o relato de um surto de TPB em uma fazenda de produção de bovinos de corte e com alta infestação do carrapato (Rhipicephalus microplus). A fazenda adquiriu 157 animais puros de origem, da raça Hereford, proveniente de uma fazenda sem presença do vetor. No dia anterior ao transporte, os animais receberam quimioprofilaxia com dipropionato de imidocarb (3mg/Kg/SC), repetindo-se 21 dias após a primeira aplicação. Aos 42 dias, alguns bezerros manifestaram sinais clínicos compatíveis com TPB, sendo confirmado pelo exame clínico, necropsia, análises histopatológicas e hemoparasitológicas. A morbidade foi de 37,6% (59/157), e a letalidade de 24,8% (39/157). A categoria de bezerros recém desmamados foi a mais acometida, com morbidade de 100% (52/52) e letalidade de 73% (38/52). A quimioprofilaxia associada à utilização de ectoparasiticidas foram insuficientes para evitar a ocorrência do surto da enfermidade.

Serological detection and molecular characterization of piroplasmids in equids in Brazil.

Equine piroplasmosis is a disease caused by the hemoparasites Babesia caballi and Theileria equi and is considered to be the most important parasitic infection affecting Equidae. The objective of the present study was to carry out an epidemiological molecular and serological survey for the presence of these two protozoal organisms in equids from the northwestern region of the State of Rio Grande do Sul (RS), south Brazil. For this purpose, blood samples were collected from 90 equids in the city of Passo Fundo, RS, Brazil. Those were animals used for sport activities, outdoor recreational riding, and work including cattle herding and mounted patrol. Anti-T. equi and anti-B. caballi IgG antibodies were detected in the sera of those animals by commercial ELISA kits. The molecular diagnosis of equine piroplasmosis due to T. equi or B. caballi (or both) consisted in the amplification of the 18S rRNA gene by nested PCR followed by sequencing of the amplified PCR product and sequence comparison and phylogenetic analysis of the isolates; 17 (18.9%) and 5 (5.55%) out of the 90 serum samples tested in this study were positive for T. equi and B. caballi, respectively. Piroplasmid 18S rRNA gene fragments were detected by PCR in 24.4% (22/90) of the samples analysed and shared 99-100% identity with sequences of T. equi by BLASTn. Samples for the phylogenetic analysis were divided into 2 groups. In group A, there was close phylogenetic relationship between 4 sequences and sequences previously reported along the US-Mexico border, in South Africa, and in Brazil. There was a phylogenetic proximity between 5 samples from group B and samples tested by other authors in the US and Spain. Variation of the 18S rRNA gene allowed the identification of 9 new T. equi genotypes in the geographical region studied.

Rangelia vitalii, Babesia spp. and Ehrlichia spp. in dogs in Passo Fundo, state of Rio Grande do Sul, Brazil.

Pathogens transmitted by ticks are an emerging problem worldwide, this study aimed to diagnose the causal agents of infection in dogs presenting suspected hemoparasitoses. Fifty-eight dogs with clinical signs such as depression, hemorrhagic diathesis and fever were evaluated regarding clinical presentation, hemogram, blood smears and serological tests, using the indirect immunofluorescence method for the agents Babesia vogeli and Ehrlichia canis and conventional PCR for Babesia spp. (gene 18S rRNA), Rangelia vitalii (gene 18S rRNA) and Ehrlichia spp. (gene dsb). Five (8.6%) of the 58 dogs were serologically positive for Babesia spp. and three (5.1%) for E. canis. Four dogs (6.8%) were positive for R. vitalii through the molecular diagnosis. The PCR products were sequenced and the DNA from R. vitalii was found to be 99% genetically identical to samples of R. vitalii that had been isolated in Brazil. No presence of Babesia spp. or E. canis was observed through PCR on the dogs evaluated here. The results indicate the presence of R. vitalii and exposure to Babesia spp. and Ehrlichia spp. among the dogs analyzed.

Rangelia vitalii, Babesia spp. and Ehrlichia spp. in dogs in Passo Fundo, state of Rio Grande do Sul, Brazil / Rangelia vitalii, Babesia spp. e Ehrlichia spp. em cães de Passo Fundo, estado do Rio Grande do Sul, Brasil

Abstract Pathogens transmitted by ticks are an emerging problem worldwide, this study aimed to diagnose the causal agents of infection in dogs presenting suspected hemoparasitoses. Fifty-eight dogs with clinical signs such as depression, hemorrhagic diathesis and fever were evaluated regarding clinical presentation, hemogram, blood smears and serological tests, using the indirect immunofluorescence method for the agents Babesia vogeli and Ehrlichia canis and conventional PCR for Babesia spp. (gene 18S rRNA), Rangelia vitalii (gene 18S rRNA) and Ehrlichia spp. (gene dsb). Five (8.6%) of the 58 dogs were serologically positive for Babesia spp. and three (5.1%) for E. canis. Four dogs (6.8%) were positive for R. vitalii through the molecular diagnosis. The PCR products were sequenced and the DNA from R. vitalii was found to be 99% genetically identical to samples of R. vitalii that had been isolated in Brazil. No presence of Babesia spp. or E. canis was observed through PCR on the dogs evaluated here. The results indicate the presence of R. vitalii and exposure to Babesia spp. and Ehrlichia spp. among the dogs analyzed.

Resumo Patógenos transmitidos por carrapatos são um problema emergente em todo o mundo, o trabalho objetivou diagnosticar os agentes causais da infecção em cães com suspeita de hemoparasitoses. Cinquenta e oito caninos com sinais clínicos como depressão, diáteses hemorrágicas e febre foram avaliados quanto à apresentação clínica, hemograma, esfregaço sanguíneo, sorologia pelo método de Imunofluorescência Indireta para os agentes Babesia vogeli e Ehrlichia canis e na PCR convencional para Babesia spp. (gene 18S rRNA), Rangelia vitalii (gene 18S rRNA) e Ehrlichia spp. (gene dsb). Cinco (8,6%) dos 58 cães apresentaram sorologia positiva para Babesia spp. e três (5,1%) para E. canis. Quatro (6,8%) animais mostraram-se positivos para R. vitalii no diagnóstico molecular. Os produtos da PCR foram sequenciados e o DNA encontrado de R. vitalii mostrou 99% de identidade genética com amostras de R. vitalii isoladas no Brasil. Não foi observada a presença de Babesia spp. e E. canis na PCR dos cães avaliados. Os resultados indicaram a presença de R. vitalii e exposição a Babesia spp. e Ehrlichia spp. entre os cães analisados.

Re-emergence of Chorioptes bovis (Acari: Psoroptidae) in cattle in the state of Rio Grande do Sul, Brazil.

Here we describe an outbreak of chorioptic mange in cattle, 56 years after its first identification in Brazil. Between the months of June and July 2011, dermatitis characterized by alopecia and crusted and thickened skin at the insertion of the tail and in the ischiorectal fossa was recognized in 40 (35.7%) out of 112 Holstein cows on a farm in the northeastern mesoregion of the state of Rio Grande do Sul, Brazil. After diagnosing mange caused by Chorioptes bovis, the cows were weighed and treated with 0.5% ivermectin, as a pour-on single dose, and were separated into two groups: cows in early lactation and those in late lactation. The survival rate of C. bovis and the healing rate in the two groups of infested cows were monitored every seven days through skin scrapings. After 28 days of evaluation, the cure rate through treatment was greater among cows in early lactation (p <0.0001). The survival rate of C. bovis was higher in cows in late lactation.

Re-emergence of Chorioptes bovis (Acari: Psoroptidae) in cattle in the state of Rio Grande do Sul, Brazil / Reemergência de Chorioptes bovis (Acari: Psoroptidae) em bovinos no Estado do Rio Grande do Sul, Brasil

Here we describe an outbreak of chorioptic mange in cattle, 56 years after its first identification in Brazil. Between the months of June and July 2011, dermatitis characterized by alopecia and crusted and thickened skin at the insertion of the tail and in the ischiorectal fossa was recognized in 40 (35.7%) out of 112 Holstein cows on a farm in the northeastern mesoregion of the state of Rio Grande do Sul, Brazil. After diagnosing mange caused by Chorioptes bovis, the cows were weighed and treated with 0.5% ivermectin, as a pour-on single dose, and were separated into two groups: cows in early lactation and those in late lactation. The survival rate of C. bovis and the healing rate in the two groups of infested cows were monitored every seven days through skin scrapings. After 28 days of evaluation, the cure rate through treatment was greater among cows in early lactation (p <0.0001). The survival rate of C. bovis was higher in cows in late lactation.

O objetivo deste estudo foi descrever um surto de sarna corióptica em bovinos, 56 anos após a sua primeira identificação no Brasil. Entre os meses de junho a julho de 2011, a dermatite caracterizada por alopecia, com crosta e espessamento da pele na inserção da cauda e na fossa isquiorretal, foi observada em 40 (35,7%) de 112 vacas holandesas de uma propriedade rural pertencente à Mesorregião do Nordeste do Estado do Rio Grande do Sul, Brasil. Após o diagnóstico da sarna causada por Chorioptes bovis, as vacas foram pesadas, tratadas com 0,5% de ivermectina pour on em dose única e separadas em dois grupos: vacas no início da lactação e no final da lactação. A taxa de sobrevivência de C. bovis e a taxa de cura dos dois grupos de vacas infestadas foram monitoradas a cada sete dias por meio de raspas de pele. Após 28 dias do estudo, a taxa de cura com o tratamento foi maior em vacas no início da lactação (p <0,0001). A taxa de sobrevivência de C. bovis foi maior em vacas no final da lactação.