Effect of "heat shock" treatments on QPX disease and stress response in the hard clam, Mercenaria mercenaria.

The hard clam, Mercenaria mercenaria, is one of the most valuable commercial mollusk species along the eastern coast of the United States. Throughout the past 2 decades, the hard clam industry in the Northeast was significantly impacted by disease outbreaks caused by a lethal protistan parasite known as Quahog Parasite Unknown (QPX). QPX is an opportunistic pathogen and the infection has been shown to be a cold water disease, where warmer conditions (above 21°C) lead to disease reduction and clam healing. In vitro studies also showed a sharp reduction in parasite growth and survivorship at temperatures exceeding 27°C. In this study, we evaluated the effect of short-term exposures to high temperatures on QPX disease dynamic and clam recovery. Infected clams were collected from an enzootic site and subsequently submitted to one of ten "heat shock" treatments involving a gradient of temperatures and exposure times. QPX prevalence was compared before and 10weeks after heat shock to assess the effect of each treatment on disease progress. Expression of several stress-related genes was measured 1 and 7days after heat shock using qPCR to evaluate the effect of each treatment on clam physiology. Anti-QPX activity in clam plasma was also measured in an attempt to link changes in defense factors to thermal stress and disease progress. Our results suggest that brief exposures to moderate high temperatures promote the greatest remission while imposing the mildest stress to clams. These results are discussed with the aim of providing the industry with possible strategies to mitigate QPX disease.

A review of sexually transmitted bovine trichomoniasis and campylobacteriosis affecting cattle reproductive health.

The objective is to discuss sexually transmitted diseases caused by Tritrichomonas foetus (T foetus) and Campylobacter fetus (C fetus) subsp. venerealis, with a focus on prevalence, pathogenesis, and diagnosis in cows and bulls. Diagnosis and control are problematic because these diseases cause severe reproductive losses in cows, but in bulls are clinically asymptomatic, which allows the disease to flourish, especially in the absence of legislated control programs. We review research regarding prophylactic systemic immunization of bulls and cows with antigens of T foetus and C fetus venerealis and their efficacy in preventing or clearing preexisting infections in the genital tract. Current diagnostic methods of C fetus venerealis and T foetus (microbial culture and PCR) should be improved. Review of the latest advances in bovine trichomoniasis and campylobacteriosis should promote knowledge and provide an impetus to pursue further efforts to control bovine sexually transmitted diseases.

[Equine protozoal myeloencephalitis in the Netherlands? An overview]. / Equine protozoal myeloencephalitis (EPM) in Nederland?

Equine protozoal myeloencephalitis (EPM) was diagnosed in a Dutch Warmblood gelding a few months after its export to the United States. The horse came back and was treated here. Additionally, an overview of the disease complex 'EPM' is given. Mode of infection, diagnosis of disease and its differential diagnoses, and general therapeutic options are presented. Although EPM due to infection with Sarcocystis neurona in Europe seems restricted to those horses that return or are imported from North America, the possibility of future cases of EPM caused by an infection with Neospora spp. is briefly discussed.

Avaliação da eficácia do colostro bovino hiperimune na infecção experimental de roedores com Cryptosporidium parvum

O Cryptosporidium parvum é um protozoário que inicialmente estava associado à AIDS. Posteriormente, diversos surtos de criptosporidiose de veiculação hídrica passaram a ser descritos. Nenhuma droga foi eficaz no controle dessa infecção. Alguns estudos mostraram eficácia do colostro de vacas hiperimunizadas com C. parvum. Vários camundongos e ratos foram inoculados com 2x10 oocistos de C.parvum. O colostro bovino hiperimune empregado no experimento foi positivo até a diluição de 1:55.000. Dois modelos murinos com imunossupressão - C57BL/6 knock out de CD4 e BALB/c nude não desenvolveram infecção até o 18º dia pós-inoculação. Os resultados mostraram que os camundongos C57BL/6 e os ratos Fischer 344 (F344) recém-nascidos são susceptíveis à infecção com esse parasita. O colostro hiperimune reduziu o número de ooscitos de C. parvum em ambas as linhagens. Entretanto, apenas os ratos F344 evidenciaram maior preservação da arquitetura da mucosa intestinal quando foram tratados com esse produto. A linhagem de ratos F344 demonstrou ser um modelo experimental adequado e promissor para o estudo da infecção com C. parvum.

Avaliação da eficácia do colostro bovino hiperimune na infecção experimental de roedores com Cryptosporidium parvum / Evaluation of the efficacy of hyperimmune bovine colostrum on Cryptosporidium parvum experimental infection of rodents

O Cryptosporidium parvum é um protozoário que inicialmente estava associado à AIDS. Posteriormente, diversos surtos de criptosporidiose de veiculação hídrica passaram a ser descritos. Nenhuma droga foi eficaz no controle dessa infecção. Alguns estudos mostraram eficácia do colostro de vacas hiperimunizadas com C. parvum. Vários camundongos e ratos foram inoculados com 2x10 oocistos de C.parvum. O colostro bovino hiperimune empregado no experimento foi positivo até a diluição de 1:55.000. Dois modelos murinos com imunossupressão - C57BL/6 knock out de CD4 e BALB/c nude não desenvolveram infecção até o 18º dia pós-inoculação. Os resultados mostraram que os camundongos C57BL/6 e os ratos Fischer 344 (F344) recém-nascidos são susceptíveis à infecção com esse parasita. O colostro hiperimune reduziu o número de ooscitos de C. parvum em ambas as linhagens. Entretanto, apenas os ratos F344 evidenciaram maior preservação da arquitetura da mucosa intestinal quando foram tratados com esse produto. A linhagem de ratos F344 demonstrou ser um modelo experimental adequado e promissor para o estudo da infecção com C. parvum.(AU)