Maternal immune response in the placenta of sheep during recrudescence of natural congenital infection of Neospora caninum.

In order to gain further insight into the pathogenesis and transmission of ovine neosporosis, the serological response of 13 naturally infected pregnant sheep was monitored. All sheep were euthanized upon the detection of a sharp increase in the level of specific antibodies against N. caninum in order to study the maternal immune response after the recrudescence of a chronic infection. Ten sheep were euthanized between 84 and 118 days of gestation, whereas the three remaining and three control not infected, pregnant sheep were euthanized at 135 days of gestation after no sharp increase in antibodies was detected. Vertical transmission was confirmed in 11 sheep by detection of N. caninum-DNA in at least one fetus, confirming recrudescence. Not all of fetuses showed pathologic microscopic lesions, however, multifocal non-purulent encephalitis was the main finding. Furthermore, nine out of the 11 vertical transmission positive sheep had lesions in placentomes (mainly multifocal necrotic foci), and the parasite was detected in eight out of 11 placentas by PCR and/or immunohistochemestry. The placentomes from sheep that suffered recrudescence showed an increased number of T lymphocytes CD3+ (CD4/CD8 < 1) and macrophages (MHC-II+), assessed by immunohistochemestry, together with an up-regulation of IFN-γ, IL-10, IL-4, TNFα, IL-2 and IL-18. IL-17 was only upregulated in the three infected sheep that did not have a sharp increase in antibody levels. In the sheep that showed fetal death at the time of euthanasia (n = 3) the placental microscopic lesions were more severe, the inflammatory infiltrate was higher, and the upregulation of cytokines was greater than in those sheep carrying viable fetuses. This study suggests that, similarly to bovine neosporosis, the time of gestation when recrudescence occurs determines the viability of the fetuses and, thus, seems to be related to the severity of lesions and immune response in the placenta. These results suggest that there might be a correlation, either as cause or as a consequence, between protection against vertical transmission of the parasite and a milder maternal serological response together with a high level of transcription of IL-17 in the placenta.

Nephrotoxicosis in Iberian piglets subsequent to exposure to melamine and derivatives in Spain between 2003 and 2006.

Between November 2003 and September 2006, 300 to 400 45-60-day-old Iberian piglets developed anorexia, polydipsia, and lethargy. Piglets were from 5 different farms in the western part of Spain. Morbidity was between 40% and 60%, and mortality ranged from 20% to 40% of the total population of postweaning piglets. In the 9 piglets in which postmortem examinations were conducted, kidneys were enlarged with yellow foci in the cortex and medulla. Microscopically, these foci were accumulations of crystals within the lumina of dilated distal tubules and collecting ducts, causing flattening of the renal tubular epithelial cells. The crystals displayed a multicolored birefringence under cross-polarized light. The multinucleated giant cells surrounding the crystals, interstitial fibrosis, and nonsuppurative infiltrates indicated a chronic inflammatory response. Toxicologic analysis of fixed kidney tissues from 4 piglets demonstrated the presence of melamine, ammeline, ammelide, and cyanuric acid. Ammelide concentrations were highest, ranging from 39,000 to 92,000 mg/kg, followed by ammeline (20,000-34,000 mg/kg), melamine (9,200-29,000 mg/kg), and cyanuric acid (2,200-9,100 mg/kg). The clinical, histologic, and toxicologic findings in affected piglets were similar to those reported in dogs and cats that died of melamine and melamine analogue-associated renal failure in 2004 and 2007. To the authors' knowledge, this is the first documented report of poisoning due to melamine and its analogues in pigs and demonstrates that contamination of pig feed occurred as early as 2003.

Comparison of three immunological diagnostic tests for the detection of avian tuberculosis in naturally infected red deer (Cervus elaphus).

Cases of tuberculosis due to Mycobacterium avium subsp. avium in 52 adult red deer (Cervus elaphus) from a farm were studied using different diagnostic techniques. Immunological probes consisted of the comparative cervical tuberculin (CCT) skin test, the interferon-gamma (IFN-gamma) assay, and 2 enzyme-linked immunosorbent assays (ELISAs) employing either avian purified protein derivatives or protoplasmatic antigen (PPA-3) as antigens. Three of the animals were euthanized due to severe weakness, loss of weight, and emaciation. Macroscopically, the 3 animals showed tuberculous lesions located mainly in lymph nodes of the digestive system and small intestine but also in other organs and lymph nodes. Polymerase chain reaction was carried out on samples from the 3 deer using primers to detect IS901, IS900, and IS6110, specific for Mycobacterium avium subsp. avium, Mycobacterium avium subsp. paratuberculosis, and Mycobacterium tuberculosis complex, including Mycobacterium bovis, respectively. The last 2 agents cause pathologies very similar to avian tuberculosis in deer. The 3 deer were strongly positive by both ELISAs, slightly positive by the IFN-gamma test, and 1 of 2 was positive by the CCT test. As with domestic ruminants, ELISA could detect deer in an advanced stage of infection, with large numbers of mycobacteria.

Aleutian disease serology, protein electrophoresis, and pathology of the European mink (Mustela lutreola) from Navarra, Spain.

The European mink, Mustela lutreola, has suffered a dramatic decline in Europe during the 20th century and is one of the most endangered carnivores in the world. The subpopulation of European mink from Navarra, Spain, estimated to number approximately 420, represents approximately two thirds of the total number of mink in Spain. Aleutian Disease Virus (ADV) is a parvovirus with a high degree of variability that can infect a broad range of mustelid hosts. The pathogenesis of this virus in small carnivores is variable and can be influenced by both host factors (e.g., species, American mink genotype, and immune status) and viral strain. A cross-sectional study was conducted during the pre-reproductive period of February-March 2004 and 2005 and the postreproductive period of September-December 2004. Mink were intensively trapped along seven rivers that were representative of the European mink habitat in Navarra. Antibody counter immunoelectrophoresis against ADV was performed on 84 European mink blood samples. All the samples were negative. Protein electrophoresis was performed on 93 plasma samples. Nine of those samples (9.6%) had gamma globulin levels exceeding 20% of the total plasma protein. Complete necropsies were performed on 23 cadavers of European mink collected in the area between 2000 and 2005. Seventeen of the mink (74%) had traumatic and hemorrhagic lesions compatible with vehicular impact injuries. Although there were no histopathologic lesions associated with ADV, this study documents the first description of a naturally occurring canine distemper virus infection in a European mink. In addition, pulmonary adiaspiromycosis in three European mink from Spain was reported.