Technical note: detection of chicken, turkey, duck, and goose tissues in feedstuffs using species-specific polymerase chain reaction

PCR method was applied for the qualitative identification of chicken (Gallus gallus), turkey (Meleagris gallipavo), duck (Anas platyrhynchos x Cairina muschata), and goose (Anser anser) tissues in feed-stuffs, on an individual basis. The assay uses oligonucleotide primers that are specific for each avian species, targeting the 12S rRNA mitochondrial gene. The primers designed generated amplicons of 95, 122, 64, and 98 bp length for chicken, turkey, duck, and goose, respectively. The specificity of the primers was tested against 29 animal species including mammals, birds, and fish, as well as 8 plant species. Analysis of experimental feedstuffs demonstrated the detection of each target species in the range of 0.1 to 100%. The performance of this method was not affected by prolonged heat-treatment (up to 133 degrees C for 20 min at 300 kPa), and consequently, it could be very useful for the accurate identification of tissues from these 4 avian species in products submitted to denaturing technologies, for which other methods cannot be applied.     

First detection of canine parvovirus type 2c in South America

Since its sudden emergence in the early 1970s, canine parvovirus type-2 (CPV-2) has been evolving through the generation of novel genetic and antigenic variants (CPV-2a/b/c and a number of additional mutations) that are unevenly distributed throughout the world. In order to develop strategies to control the spread of these variants and to understand virus evolution is fundamental to genotype field isolates from different geographic locations. In the present paper we have examined 25 isolates of CPV from clinical samples of Uruguayan dogs collected during year 2006. A fragment of the VP2 gene of the virus was analyzed using polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP) and DNA sequence analysis. Out of the 25 isolates analyzed, only one was characterized as CPV-2a and 24 were characterized as CPV-2c, indicating that this type is currently the prevalent field CPV circulating in Uruguay. This is the first report of CPV-2c in the American continent and it also represents the highest frequency of this type observed in a dog population so far. Its presence in South American supports the assumption that CPV-2c is reaching a worldwide distribution as occurred with 2a/2b antigenic types.     

Estimation of canine intestinal parasites in Córdoba (Spain) and their risk to public health

The prevalence of gastrointestinal parasites in dogs was studied in the province of Córdoba (southern Spain), with special attention to those parasites that can be transmitted to man. The experiment was completed with the examination of soil samples from public parks and city gardens. The study was carried out over a population of 1800 animals entered in the Control Animal Centre (CECA) by coprological methods, and within this group, 300 dogs were sacrificed and necropsied. The prevalence of any intestinal parasitic infection was 71.33%. The following parasites of the gastrointestinal tract were recorded: Isospora canis (22%), Isospora (Cystoisospora) spp. (10.22%), Sarcocystis (2.5%), Hammondia/Neospora (1.94%), Giardia canis (1%), Dipylidium caninum (13.2%), Taenia hydatigena (7.66%), Taenia pisiformis (4%), Uncinaria stenocephala (33.27%), Toxascaris leonina (14.94%), Toxocara canis (17.72%) and Trichuris vulpis (1.66%). Related to public health, it is important to point out the presence of T. canis only in puppies younger than one year and Uncinaria, more frequent in adult dogs. Soil samples of parks revealed the presence of eggs of Toxocara, and it suggests the existence of real risk for human infection.     

Association of hepatitis E virus (HEV) and postweaning multisystemic wasting syndrome (PMWS) with lesions of hepatitis in pigs

The aim of the study was to determine the presence of swine hepatitis E virus (HEV) RNA and antibodies in postweaning multisystemic wasting syndrome-affected (n=114) and non-affected (n=46) pigs and the possible association with hepatitis lesions. Forty-four pigs were RT-PCR positive (28.2%); 25 of them were PMWS cases, while 19 were non-PMWS pigs. In both groups, HEV RT-PCR results were associated with hepatitis (OR=5.61 for PMWS-affected pigs and OR=5.17 for non-PMWS affected pigs; p=0.01). No interaction was detected in a logistic regression between PMWS occurrence and HEV infection for the development of hepatitis lesions. Seropositivity to HEV was more likely to occur in pigs with hepatitis (51.9%) compared to pigs without hepatitis (36.1%; p=0.03). Significant differences in optical densities were notices comparing the lesional stage of pigs (p=0.009). While pigs with slight or moderate hepatitis were seropositive, pigs with more severe lesions were seronegative to HEV. These results indicate that swine HEV infection can be a significant contributor to the development of moderate hepatitis in pigs regardless of the PMWS status.     

Biosecurity measures on swine farms in Spain: perceptions by farmers and their relationship to current on-farm measures

A survey was conducted on 172 farms belonging to the same company in order to ascertain the biosecurity measures applied and the importance that farmers attributed to each measure. A questionnaire about general data, the opinions of farmers about biosecurity measures, and a detailed checklist of the biosecurity measures actually applied on the farm was completed for each one of the participating farms. Opinion data were initially analysed by means of a cluster analysis (multidimensional scaling method); then, a logistic regression was used to analyse the relationship between the perceptions of the farmer and the measures applied on the farm. In general, farmers implemented measures to reduce risks of contamination from people and animals other than pigs. In contrast, biosecurity measures related to replacement stock were not applied as often. On average, the farmers scored the biosecurity on their own farms as 6.7 on a scale of 0-10. The most important measures, according to the farmers' perceptions, were the availability of a sanitary ford, a fence around the farm, the restriction of visits and vehicles, using bird-proof nets in windows, having changing facilities, applying quarantines, and the use of other measures related to replacement stock. The perception of a given measure was strongly influenced by the measures actually applied on the farm. Thus, for example, those who did not have a sanitary ford highlighted the importance of disinfecting vehicles while those who had one neglected this type of disinfection. In conclusion, knowledge of the relationships between perceptions and measures taken is important in developing effective biosecurity strategies on pig farms.     

Immune response to and tissue localization of the Wolbachia surface protein (WSP) in dogs with natural heartworm (Dirofilaria immitis) infection

Human and animal parasitic filarial nematodes, including the agent of canine and feline heartworm disease Dirofilaria immitis, harbour intracellular bacteria of the genus Wolbachia (Rickettsiaies). It is thought that these bacteria play an important role in the pathogenesis and immune response to filarial infection. Immunoglobulin G (total IgG, IgG1, IgG2) production against and immunohistochemical staining of tissues for the Wolbachia surface protein (WSP) from dogs with natural heartworm infection were evaluated. All infected dogs had significant total anti-WSP IgG levels compared to healthy controls. Interestingly, WSP was recognized by the IgG2 subclass in both microfilariemic dogs and in dogs with no circulating microfilariae (occult infection). However, microfilariemic dogs also produced gG1 antibodies. Positive staining for WSP was observed in lungs, liver and kidneys, in particular in glomerular capillaries of naturally infected dogs who had died from heartworm disease. Our results show for the first time that Wolbachia is recognized specifically by D. immitis--infected dogs and that the bacteria is released into host tissue. Furthermore, microfilariemic status appears to effect immune responses to this endosymbiont.     

Serum immunoglobulin G concentration in Southern elephant seal, Mirounga leonina (Linnaeus, 1758), from Elephant Island (Antarctica): sexual and adrenal steroid hormones effects

Serum immunoglobulin G (IgG; indirect enzyme-linked immunosorbent assay), as well as sexual and adrenal steroid hormones' concentrations (radioimmunoassay) were determined in 63 (male and female) Southern elephant seals (Mirounga leonine) at different developmental stages (weaned pups, juveniles and adults). In females, IgG values (mean+/-S.D.) were higher (P<0.05) in adults (15.9+/-6.5mg ml(-1)) than in juveniles (7.9+/-4.0mg ml(-1)), but similar to weaned pups (12.0+/-5.0mg ml(-1)). Estrogen concentration was higher (P<0.05) in adults than in the weaned pups. In females, a significant (P<0.05) correlation (R=0.4) between serum IgG level and progesterone concentration was observed. In males, testosterone concentration was higher (P<0.05) in adults than in the juveniles and weaned pups. Aldosterone and cortisol concentrations were higher (P<0.05) in weaned pups (1056.0+/-643.1pmol 1(-1) and 272.7+/-110.0 nmol 1(-1), respectively) than in the juveniles (638.6+/-579.7pmol1(-1) and 152.9+/-97.3nmol 1(-1), respectively) and adults (386.5+/-209.1pmol (-1) and 145.7+/-67.3nmol 1(-1), respectively). These findings indicate that weaned pups are subjected to a higher natural stressful condition in the field. Despite this, humoral immunity, measured through IgG concentration, is not impaired in weaned pups.     

Expression of maspin in mammary gland tumors of the dog

Maspin is a serine protease inhibitor that inhibits tumor invasion and metastasis in human breast cancer and is consistently expressed by mammary myoepithelial cells (MECs). To analyze the value of maspin as a marker of the MEC layer of the normal and tumoral canine mammary gland, the immunohistochemical expression of maspin was studied in formalin-fixed tissues from 55 benign and malignant tumors (40 tumors also contained the surrounding normal mammary gland) using a commercially available monoclonal antibody. Periacinar and periductal MECs of all 40 normal mammary glands were stained by the anti-human maspin monoclonal antibody, and immunoreactivity was observed in the nucleus and cytoplasm of these cells. In addition, maspin was found in 53 (98%) of the tumors studied, reacting with the MECs in 100% of benign tumors and 93% of malignant tumors and to the epithelial cells of 16% of benign and 73% of malignant tumors. In the MEC compartment, immunoreactivity was observed in the cytoplasm of hypertrophic MECs, fusiform MECs, stellate MECs, rounded (myoepithelial) cells, and chondroblasts. In the epithelial cell compartment, immunoreactivity was observed in the cytoplasm of cells with and without squamous differentiation. Stromal myofibroblasts were unreactive. Maspin appears to be a very sensitive marker of the normal and neoplastic myoepithelium that, contrary to smooth muscle differentiation markers, does not stain stromal myofibroblasts. In addition, a subset of neoplastic epithelial cells reacted with the maspin antibody. The relationship between maspin expression in different cellular compartments of canine mammary carcinomas and the biologic aggressiveness of the disease remains to be elucidated.     

Fatal placental subinvolution in a captive capybara (Hydrochaeris hydrochaeris, Order Rodentia)

An adult, captive-born female capybara died of systemic thrombosis and hemoperitoneum associated with placental subinvolution. Grossly, the uterus was enlarged, segmentally thickened, and associated with a large blood clot in the abdominal cavity. There was hemometra and a large ovoid mass in each uterine horn weakly adhered to the endometrium, and the right uterine horn wall had a small perforation over the mass. The mesometrial veins were markedly dilated due to thrombosis and occasionally perforated. Histologically, the uterine masses consisted of partly necrotic placental and subplacental tissue. The uterine wall surrounding the masses had full-thickness coagulative necrosis of the myometrium and diffuse endometrial ulceration with abundant syncytiotrophoblast-like cells within capillaries. Vascular lesions in the uterus and mesometrium consisted of mural invasion by cytotrophoblast and syncytiotrophoblast-like cells, thrombosis, fibrinoid necrosis, and/or heterophilic vasculitis. This is the first report of placental subinvolution in capybaras or any rodent species, to the authors' knowledge.     

Giardia intestinalis and other zoonotic parasites: prevalence in adult dogs from the southern part of Mexico City

The protozoan Giardia intestinalis is a mammalian-infecting parasite. It produces diarrhoea and malabsorption in its hosts. There is growing evidence that dogs could be reservoirs and play an important role in transmission. In Mexico, there are few data on the frequency of G. intestinalis. Therefore, we studied the small intestine of stray dogs, euthanazed at the "Culhuacan" Control Canine Centre, towards the end of 1997 and during the summer of 1998. We microscopically analysed intestinal contents and mucus samples taken every 3cm. During the cold season (winter), parasites were not found in 38/100 dogs, in contrast to 8/100 through the warm season. We found that 42/100 in winter and 51/100 in summer harboured G. intestinalis. To our knowledge, these G. intestinalis frequencies are the highest found in adult dogs worldwide. The results showed a rise in Ancylostoma spp. from 23/100 to 67/100 during the cold and warm seasons. Toxocara canis frequencies varied between 12/100 and 18/100, respectively. The data suggest that the probability of infection is higher during the hottest months compared to the coldest months of the year. Both puppies and adult dogs are highly infected. Dogs are reservoirs for zoonotic parasites; for this reason, it is imperative for humans to avoid fecal contamination in streets, public gardens and parks.