2. Universidad Cardenal Herrera-CEU

The aim of the work was to evaluate if genetic selection for daily gain may affect the immune system. Two experiments were performed. The first one involved 80 rabbit females and their first two litters to explore the effect of selection on the ability of animals to maintain immune competence. Two generations from a line selected for average daily gain (ADG) were evaluated (VR19 generation 19th, n = 43; VR37 generation 37th, n = 37). In females, the effect of selection and its interaction with physiological state were not significant for any trait. In litters, the selection criterion increased the granulocyte to lymphocyte ratio. The second experiment involved 73 19-week-old females (VR19, n = 39; VR37, n = 34) to explore the effect of genetic selection on immune response after S. aureus infection. The VR37 rabbit females had lower counts for total lymphocytes, CD5+, CD4+, CD8+, CD25+, monocytes, the CD4+/CD8+ ratio and platelets than those of VR19 (-14, -21, -25, -15, -33, -18, -11 and -11%, respectively; P < 0.05). VR37 had less erythema (-8.4 percentage points; P < 0.05), fewer nodules (-6.5 percentage points; P < 0.05) and a smaller nodule size (-0.65 cm3 on 7 day post-inoculation; P < 0.05) compared to VR19. Our study suggests that genetic selection for average daily gain does not negatively affect the maintenance of a competent immune system or the ability to establish immune response. It seems that such selection may improve the response to S. aureus infections.

During a 12 month period, a group of 14 medusa-stage jellies of the genus Chrysaora, including Pacific sea nettle (Chrysaora fuscescens, n = 11) and Japanese sea nettle (Chrysaora pacifica, n = 3), that were maintained in a public aquarium developed progressive ulcerative umbrellar lesions. In 6 cases (42.9%), ulceration was deep, transmural, and perforated through the mesoglea and subumbrella. In 6 cases (42.9%), ciliated protozoa histomorphologically consistent with scuticociliates were observed in the mesoglea and gastrovascular cavity. In 2 cases (14.3%), commensal dinoflagellates (zooxanthellae) were in the mesoglea and in the cytoplasm of the scuticociliates. During this period, water quality parameters including temperature [°C], pH, oxidation-reduction potential (ORP) [mV], salinity [psu], dissolved oxygen [%], ammonia (NH3), and nitrite (NO2) levels were monitored daily or weekly. The main water quality abnormalities were increased NO2 and pH levels above recommended reference ranges for C. fuscescens and elevated temperature above recommended reference ranges for C. pacifica tank. After correction of water quality parameters, apparent improvement of jellies was observed. In this case, environmental factors were considered the most likely predisposing factors for the development of ulcerative lesions, and ciliated protozoa were considered secondary rather than primary pathogens.