Adhesion properties, fimbrial expression and PCR detection of adhesin-related genes of avian Escherichia coli strains

Forty-nine avian pathogenic Escherichia coli (APEC) strains obtained from chickens suffering from septicemia (24), swollen head syndrome (14) and omphalitis (11), isolated from individuals in different regions of Brazil and from different outbreaks, were studied for their adhesion to trachea epithelial cells, fimbrial expression and hemagglutination capacity to different erythrocyte types. These results were compared with their content of fimbriae-related genes as detected by polymerase chain reaction (PCR) using specific pair of primers. The aim of these assays was to determine the importance of expression of adhesins in the pathogenic strains and to evaluate the presence of adhesin genes either previously described or not yet recognized for APEC strain. Thirty commensal strains isolated from poultry showing no signs of any of the above diseases were used to compare the results with the pathogenic isolates. The PCR assay demonstrated that septicaemic and swollen head syndrome strains had the highest number of adhesion-related genes of recognized importance in pathogenicity. Using different media for growth conditions, 40 different D-mannose resistant haemagglutination patterns were observed in this study, what indicates the expression of a great variability of surface agglutinins in these bacterial strains. Our results also showed that adhesion, whether D-mannose resistant (MRA) or D-mannose sensitive (MSA), is a characteristic observed in both pathogenic and commensal strains. Several strains with positive adherence had no genetic sequences related to the studied adhesin genes what indicates that our APEC strains probably possess a genome with adhesins genes besides those describe elsewhere and that have not yet been described.     

Prevalence of gastrointestinal nematode infections in goat flocks on semi-arid rangelands of northeastern Mexico

The objective of this study was to determine the prevalence of gastrointestinal nematode (GIN) infection in goat flocks on semi-arid rangelands of northeastern Mexico (25° N, 350–400 mm annual precipitation). The study included 668 pluriparous goats from 18 herds in five municipalities of Coahuila and Nuevo Leon, Mexico. Five genetic groups were considered (predominance of Boer, Nubian, Alpine, Saanen, and Toggenburg). Fecal samples were taken from the rectum of each animal to determine the number of eggs per gram (EPG) of GIN. The prevalence of flocks with GIN infections was 88.9%. Similar results were observed for the number of goats infected in the flocks. The Alpine breed presented the highest prevalence and highest EPG loads of GIN, whereas Boer and Nubian were the genetic groups with the lowest (P?<?0.05) EPG. There was a negative effect of GIN infection on the live weight of goats (P?<?0.05). The GIN genera found were Trichostrongylus spp. and Haemonchus spp. It was concluded that in the goat flocks of the semi-arid zones of Mexico was found a high prevalence of infections with gastrointestinal nematodes. The municipality and the breed of the animals were factors that showed influence on this prevalence and the level of infection of the goats.     

Choroid plexus carcinoma cells in the cerebrospinal fluid of a Staffordshire Bull Terrier

An 11-year-old female intact Staffordshire Bull Terrier was referred to the Queen's Veterinary School Hospital at the University of Cambridge with sudden onset of episodic behavioral changes, a mammary mass, and papilledema in the right eye. On physical examination the dog appeared depressed and had a head tilt to the right with anisocoria. Using magnetic resonance imaging, a broad-based lesion that obliterated the fourth ventricle was detected in the right brainstem. There was no evidence of pulmonary metastasis. Cerebrospinal fluid (CSF) was then obtained; fluid analysis showed an increased cell count (165 cells/μL, reference interval 0-7 cells/μL) and total protein (0.30 g/L, reference value <0.25 g/L). Cytologic evaluation revealed a population of atypical epithelial cells arranged in cohesive rafts and characterized by moderate to occasionally marked anisocytosis and anisokaryosis. The appearance was highly suspicious of a malignant epithelial neoplasm. The dog was euthanized and on postmortem examination an asymmetrical nonencapsulated cerebellar mass was found within the choroid plexus of the fourth ventricle with local extension into the cerebellopontine angle. Histologic sections of the cerebellar mass contained arborizing papillary structures covered by a single layer of atypical epithelial cells that showed local infiltration into the adjacent neuropil. The diagnosis was choroid plexus carcinoma. The atypical epithelial cells were negative for pancytokeratin and strongly positive for vimentin. The finding of clusters of choroid plexus epithelial cells in the CSF demonstrates the value of utilizing a relatively noninvasive diagnostic technique for diagnosis of choroid plexus tumors.     

Development of genomic predictions for Angus cattle in Brazil incorporating genotypes from related American sires

Genomic prediction has become the new standard for genetic improvement programs, and currently, there is a desire to implement this technology for the evaluation of Angus cattle in Brazil. Thus, the main objective of this study was to assess the feasibility of evaluating young Brazilian Angus (BA) bulls and heifers for 12 routinely recorded traits using single-step genomic BLUP (ssGBLUP) with and without genotypes from American Angus (AA) sires. The second objective was to obtain estimates of effective population size (N_e) and linkage disequilibrium (LD) in the Brazilian Angus population. The dataset contained phenotypic information for up to 277,661 animals belonging to the Promebo breeding program, pedigree for 362,900, of which 1,386 were genotyped for 50k, 77k, and 150k single nucleotide polymorphism (SNP) panels. After imputation and quality control, 61,666 SNPs were available for the analyses. In addition, genotypes from 332 American Angus (AA) sires widely used in Brazil were retrieved from the AA Association database to be used for genomic predictions. Bivariate animal models were used to estimate variance components, traditional EBV, and genomic EBV (GEBV). Validation was carried out with the linear regression method (LR) using young-genotyped animals born between 2013 and 2015 without phenotypes in the reduced dataset and with records in the complete dataset. Validation animals were further split into progeny of BA and AA sires to evaluate if their progenies would benefit by including genotypes from AA sires. The N_e was 254 based on pedigree and 197 based on LD, and the average LD (±SD) and distance between adjacent single nucleotide polymorphisms (SNPs) across all chromosomes were 0.27 (±0.27) and 40743.68 bp, respectively. Prediction accuracies with ssGBLUP outperformed BLUP for all traits, improving accuracies by, on average, 16% for BA young bulls and heifers. The GEBV prediction accuracies ranged from 0.37 (total maternal for weaning weight and tick count) to 0.54 (yearling precocity) across all traits, and dispersion (LR coefficients) fluctuated between 0.92 and 1.06. Inclusion of genotyped sires from the AA improved GEBV accuracies by 2%, on average, compared to using only the BA reference population. Our study indicated that genomic information could help us to improve GEBV accuracies and hence genetic progress in the Brazilian Angus population. The inclusion of genotypes from American Angus sires heavily used in Brazil just marginally increased the GEBV accuracies for selection candidates.     

A certain invariance property of BLUE in a whole‐genome regression context

A curious result from mixed linear models applied to genome‐wide association studies was expanded. In particular, a model in which one or more markers are considered as fixed but are allowed to contribute to the covariance structure by treating such markers as random as well was examined. The best linear unbiased estimator of marker effects is invariant with respect to whether those markers are employed in constructing a genomic relationship matrix or are ignored, provided marker effects are uncorrelated with those not being tested. Also, the implications of regarding some marker effects as fixed when, in fact, these possess a non‐trivial covariance structure with those declared as random were examined.     

Evaluation of surgical outcome,complications, and mortality in dogs undergoing preoperative computed tomography angiography for diagnosis of an extrahepatic portosystemic shunt: 124 cases (2005–2014)

This study evaluated the safety of preoperative computed tomography angiography (CTA) and its effect on surgical time and clinical outcomes in dogs that underwent surgical correction of a single congenital extrahepatic portosystemic shunt (CEPSS). Patient data were retrospectively collected from medical records and owner communications for 124 dogs with single CEPSS, undergoing preoperative CTA (n = 43) or not (n = 81) which were surgically treated from 2005 to 2014. The frequency of major postoperative complications was 4.7% and 9.9% for the CTA and no CTA groups, respectively (P = 0.49). Mean ± standard deviation (SD) surgical time for the preoperative CTA group was 84 ± 40 min and 81 ± 31 min for the no CTA group (P = 0.28). We conclude that anesthetized preoperative CTA appears to be a safe method for diagnosis and surgical planning in dogs with single CEPSS, and does not appear to affect surgical procedure time, complication rate, or clinical outcome.     

Incidence of and risk factors for cat bites: a first step in prevention and treatment of feline aggression

Feline aggression towards people has a smaller incidence than canine aggression, but also represents an important public health problem. The aim of this work was to analyse feline aggression reported towards people, to estimate its incidence and to assess the risk factors involved. The information was obtained from the Public Health Centres in the Valencian Region (Spain). A total of 936 acts of feline aggression were analysed. Cats inflicted 8% of all animal bites reported. The annual average was 6.36 feline aggression incidents per 100,000 people. Most aggressive incidents occurred during the summer months. Children (0-14 years old) and women were more likely to be bitten. Wounds were mainly punctures, single, and mild, and were located mostly on the hands. In children, the head and neck areas were affected much more than in adults. The cats involved in incidents were mostly Siamese, female and owned; these cats mainly attacked their owners. Most occurrences were a defensive response by the cat.