Effect of selection for growth rate on the rabbit (Oryctolagus cuniculus) immune system and its response after experimental Staphylococcus aureus infection.

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.

Pathological findings and husbandry management in captive Chrysaora spp. medusae affected by umbrellar ulcerative lesions.

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.

First molecular detection and characterization of herpesvirus and poxvirus in a Pacific walrus (Odobenus rosmarus divergens).

BACKGROUND: Herpesvirus and poxvirus can infect a wide range of species: herpesvirus genetic material has been detected and amplified in five species of the superfamily Pinnipedia; poxvirus genetic material, in eight species of Pinnipedia. To date, however, genetic material of these viruses has not been detected in walrus (Odobenus rosmarus), another marine mammal of the Pinnipedia clade, even though anti-herpesvirus antibodies have been detected in these animals. CASE PRESENTATION: In February 2013, a 9-year-old healthy captive female Pacific walrus died unexpectedly at L'Oceanografic (Valencia, Spain). Herpesvirus was detected in pharyngeal tonsil tissue by PCR. Phylogenetic analysis revealed that the virus belongs to the subfamily Gammaherpesvirinae. Poxvirus was also detected by PCR in skin, pre-scapular and tracheobronchial lymph nodes and tonsils. Gross lesions were not detected in any tissue, but histopathological analyses of pharyngeal tonsils and lymph nodes revealed remarkable lymphoid depletion and lymphocytolysis. Similar histopathological lesions have been previously described in bovine calves infected with an alphaherpesvirus, and in northern elephant seals infected with a gammaherpesvirus that is closely related to the herpesvirus found in this case. Intracytoplasmic eosinophilic inclusion bodies, consistent with poxviral infection, were also observed in the epithelium of the tonsilar mucosa. CONCLUSION: To our knowledge, this is the first molecular identification of herpesvirus and poxvirus in a walrus. Neither virus was likely to have contributed directly to the death of our animal.

Recurrent umbilical cord accidents in a bottlenose dolphin Tursiops truncatus.

Three successive umbilical cord accidents (UCAs) were diagnosed in the same female bottlenose dolphin Tursiops truncatus during consecutive gestations. In 2 of these, transabdominal ultrasonographic examination revealed coiling of the UC around the peduncle of the foetus. All 3 foetuses were male, died in utero during the last third of gestation and were spontaneously aborted. The 3 UCs were elongated, flattened and congested. For 3 subsequent pregnancies, a different sire was used for mating, handling protocols and treatments were adjusted, and 3 live female calves were successfully delivered. UC lengths were normal. UCAs are associated with excessively long UCs and are not uncommon in humans and horses but are unusual in other species. We believe this is the first detailed report of recurrent UCAs in a dolphin.

Killing niche competitors by remote-control bacteriophage induction.

A surprising example of interspecies competition is the production by certain bacteria of hydrogen peroxide at concentrations that are lethal for others. A case in point is the displacement of Staphylococcus aureus by Streptococcus pneumoniae in the nasopharynx, which is of considerable clinical significance. How it is accomplished, however, has been a great mystery, because H(2)O(2) is a very well known disinfectant whose lethality is largely due to the production of hyperoxides through the abiological Fenton reaction. In this report, we have solved the mystery by showing that H(2)O(2) at the concentrations typically produced by pneumococci kills lysogenic but not nonlysogenic staphylococci by inducing the SOS response. The SOS response, a stress response to DNA damage, not only invokes DNA repair mechanisms but also induces resident prophages, and the resulting lysis is responsible for H(2)O(2) lethality. Because the vast majority of S. aureus strains are lysogenic, the production of H(2)O(2) is a very widely effective antistaphylococcal strategy. Pneumococci, however, which are also commonly lysogenic and undergo SOS induction in response to DNA-damaging agents such as mitomycin C, are not SOS-induced on exposure to H(2)O(2). This is apparently because they are resistant to the DNA-damaging effects of the Fenton reaction. The production of an SOS-inducing signal to activate prophages in neighboring organisms is thus a rather unique competitive strategy, which we suggest may be in widespread use for bacterial interference. However, this strategy has as a by-product the release of active phage, which can potentially spread mobile genetic elements carrying virulence genes.

Computed tomographic diagnosis of unilateral cavernous sinus syndrome caused by a chondrosarcoma in a dog: a case report.

An eight-year old Rottweiler dog was presented with signs of enophthalmia, ptosis, anisocoria and mydriasis of the right eye, which showed visual disturbance, reduced or absent reflexes, and ophthalmoplegia. Consensual pupillary light reflex was also absent in the left eye. These neurological deficits were compatible with cavernous sinus syndrome. Computed tomography images of the cavernous sinus and the optical fissure revealed a mildly calcified mass arising from the right presphenoid bone extending further caudally into the orbital foramina. This extension of the mass affected the normal function of several cranial nerves. The dog was euthanased within one year of the initial presentation following development of forebrain signs. A chondrosarcoma was diagnosed histologically after necropsy.

Anatomic and computed tomographic atlas of the head of the newborn bottlenose dolphin (Tursiops truncatus).

The head of a newborn dolphin (Tursiops truncatus), that died shortly after birth was imaged using computed tomography (CT). Gross cross-sectional slices of the head were compared with the CT images to identify normal structures of the cranium, brain, and respiratory and digestive pathways. Labelled transverse CT images of the dolphin head are presented sequentially as a reference for normal anatomy.

Ectopic pregnancy in animals and humans.

Ectopic pregnancy denotes a pregnancy occurring elsewhere than in the cavity of the uterus. This pathology has been recognised for years and it causes numerous maternal deaths during the first trimester of pregnancy. While this condition is well-known in humans, it is rarely diagnosed in animals. However, the causes and mechanisms leading to an ectopic implantation of the ovum are not always clearly defined in humans or animals. Two types of ectopic pregnancy are mainly recognized: (1) tubal pregnancy occurs when an oocyte is fertilized and then remains in the oviduct and (2) abdominal pregnancy occurs when the gestation develops in the peritoneal cavity. The latter may be subdivided into two subtypes: the primary form, when a fertilized oocyte enters the peritoneal cavity and becomes attached to the mesentery or abdominal viscera, and the secondary form, which follows the rupture of an oviduct or the uterus after the fetus has been implanted, and the fetus is expelled into the peritoneal cavity. Cornual, ovarian and cervical ectopic locations are less frequent. Several differences exist in ectopic pregnancies between human beings and animal species. While abdominal pregnancy has been described in both human and animal species, tubal ectopic pregnancies would appear to be restricted to primates. Other than anecdotal cases, this pathological condition does not occur in laboratory, domestic or farm animals. Several factors are described as being the cause of these differences.