The optimal immunization procedure of DNA vaccine pcDNA–TA4–IL-2 of Eimeria tenella and its cross-immunity to Eimeria necatrix and Eimeria acervulina

The immunization procedure of DNA vaccine pcDNA–TA4–IL-2 of Eimeria tenella, including route, dose, time of immunization and age of primary immunization of chicken, was optimized. The stability and the cross-species protection of the vaccine were also analyzed. Efficacy of immunization was evaluated on the basis of oocyst decrease ratio, lesion score, body-weight gain and the anti-coccidial index (ACI). Chinese Yellow chickens were randomly distributed into corresponding groups (30/group). The challenged, unchallenged and vector control groups were designed. The results illustrated that 25 μg was the optimal dose and intramuscular injection was the most effective route to induce protective immunity. There were no significant differences of ACIs between boosting and non-boosting groups. Storage time and temperature had little effect on the immunizing efficacy of the vaccine. The vaccine could provide partial cross-protection against the challenge with E. necatrix and E. acervulina, but not with E. maxima.     

A retrospective analysis of radiation therapy for the treatment of feline vaccine‐associated sarcoma*

We retrospectively evaluated predictive prognostic factors in 73 cats with vaccine‐associated sarcoma given postsurgical curative (n = 46, most with clean margins) or coarse fractionated radiotherapy (n = 27, most with either macroscopic disease or dirty margins). The former animals displayed a median survival of 43 months and a median progression free interval (PFI) of 37 months, the latter reached a median survival of 24 months and a median PFI of 10 months. In cats undergoing coarse fractionated therapy, factors predictive of a better outcome included lack of visible mass (n = 10) as opposed to macroscopic disease (n = 17, survival: 30 versus 7 months, P = 0.025; PFI: 20 versus 4 months, P = 0.01), adjuvant chemotherapy for gross disease (n = 5/17, survival: 29 versus 5 months, P = 0.04) and a smaller number of surgeries preceding radiation therapy (coeff = 0.41, P = 0.03). The Ki67 index was not predictive for survival. We concluded that postsurgical curative and coarse fractionated radiotherapy are effective legitimate options for managing vaccine‐associated sarcomas.     

Evaluation of a new strategy to modulate skeletal development in racehorses by imposing track-based exercise during growth: the effects on 2- and 3-year-old racing careers

REASON FOR PERFORMING STUDY: No data exist on the effects of conditioning exercise at foal age on workload and subsequent clinical injury rate during their 2- and 3-year-old racing careers. OBJECTIVES: To investigate the effects of subjecting TB foals to conditioning exercise prior to the start of race training on: the workload required to reach a level of fitness sufficient to compete; and the prevalence of orthopaedic injury during the first 2 seasons of their racing careers. METHODS: Twenty 18-month-old TBs, 12 subjected to conditioning exercise at foal age (CONDEX) and 8 exercised spontaneously at pasture only (PASTEX) were trained and entered in competitive events. Workload was quantified using the cumulative workload index (the product of average velocity and distance at a specific gait) and the animals were monitored clinically and radiographically for signs of musculoskeletal disorders. RESULTS: Workload to reach the desired fitness level was similar for CONDEX and PASTEX. CONDEX performed more prerace training sessions as 2-year-olds (P<0.05). The incidence of orthopaedic injuries was low in both groups and there were no differences in the occurrence of orthopaedic ailments. PASTEX animals tended to show signs of musculoskeletal disorders earlier than CONDEX animals. This time difference was significant for metacarpophalangeal joint pain on flexion, reduced carpal flexion and hindlimb lameness (P<0.05). CONCLUSIONS: Subjecting TB foals to conditioning exercise early in life does not have adverse effects on racing careers at ages 2 and 3 years, and does not influence the workload needed to reach a fitness level that is sufficient for racing. POTENTIAL RELEVANCE: The lack of negative effects and the indications of some positive effects of early conditioning exercise in the Thoroughbred encourage further large-scale comparative studies.     

Seroepidemiology and genotyping of hepatitis E virus in Singapore reveal rise in number of cases and similarity of human strains to those detected in pig livers

Hepatitis E virus (HEV) causes 20 million infections worldwide yearly, of which only about 3.3 million are symptomatic. In developed Asian countries, HEV strains detected in human sera and in food sources were genetically similar, suggesting that indigenous HEV infections may be largely food‐borne. To assess the burden of hepatitis E in Singapore, we performed a seroepidemiologic study of the infection. Additionally, we carried out HEV genotyping on archived, residual HEV IgM‐positive serum samples collected between 2014 and 2016 (n = 449), and on pig liver samples (n = 36) purchased from wet markets and supermarkets. Our study shows a rise in hepatitis E incidence (IgM) from 1.7 to 4.1 cases per 100,000 resident population from 2012 to 2016 and an increase in hepatitis E IgG positivity rate among residents from 14% in 2007 to 35% in 2016. Other findings also suggest the epidemiology of hepatitis E in Singapore has shifted, from it being mainly a disease imported from the Indian subcontinent, to one that is now increasingly prevalent in our resident population. Genotypes obtained from 143 human samples identified the majority to be genotype 3 (n = 121), 21 to be genotype 1 and one to be genotype 4. Further phylogenetic analyses suggest genotype 3a to be the cause of indigenous infections in residents, which showed genetic similarity to the genotype 3a strains detected in pig livers. This link between the strains in the majority of human samples and those in pig livers consumed by the public suggests a possible food‐borne route of HEV infection in Singapore.     

Effects of dietary lipid levels on lipid deposition and activities of lipid metabolic enzymes in hybrid tilapia (Oreochromis niloticus × O. aureus)

This study was designed to investigate the effects of dietary lipid levels on growth performance, lipid deposition and activities of lipid metabolic enzymes in hybrid tilapia (Oreochromis niloticus × O. aureus). Four isonitrogenous (300 g/kg crude protein) experimental diets containing graded levels of lipid (25, 55, 85 and 115 g/kg) were randomly assigned to triplicate groups of 180 juvenile fish. Fish were fed twice daily for 8 weeks. At the end of the experiment, the growth performance and proximate composition of fish were determined. The activities and gene expression of lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) were assessed as well. Fish fed the diets with 55 and 85 g/kg lipid had a significantly (p < 0.05) higher body weight gain than those fed the diets with 25 and 115 g/kg lipid. The whole-body and liver lipid contents were significantly (p < 0.05) elevated with increasing dietary lipid levels. Moreover, the activities and mRNA abundances of LPL and HSL in the liver, dorsal muscle and fat tissues were markedly altered by dietary lipid levels. Our data demonstrate a profound influence of dietary lipid levels on the growth and lipid deposition in hybrid tilapia, which is likely associated with the regulation of lipid metabolic enzymes including LPL and HSL.