Detection of the enterotoxins A, B, and C genes in Staphylococcus aureus from goat and bovine mastitis in Brazilian dairy herds

To determine the distribution of genes that encode enterotoxins A, B and C, 36 strains of Staphylococcus aureus isolated from goat mastitis and 64 isolated from bovine mastitis were analyzed by Multiplex PCR. Of the total strains studied, 37 (37%) were detected to have some of the SEs genes. From the bovine mastitis strains, 4 (6.3%) co-amplified the sea and seb genes and 2 (3.1%) were positive for the sec gene. From the goat mastitis strains, 31 (86%) tested positive to the Multiplex, and the sec gene was detected in all of them. The production of SE was detected in all strains harboring the corresponding gene. The results demonstrated that S. aureus isolated from goat mastitis had a higher enterotoxigenic potential than those isolated from bovine mastitis. Additionally, the presence of the sec gene in the majority of goat mastitis strains suggests a possible involvement of SEC in goat mastitis pathogenesis.     

Attaching and effacing Escherichia coli isolated from dogs in Brazil: characteristics and serotypic relationship to human enteropathogenic E. coli (EPEC)

Escherichia coli isolates recovered from 182 fecal specimens from dogs up to five months old from the cities of S?o Paulo and Campinas, SP, Brazil, were examined by polymerase chain reaction (PCR) for several virulence factors and properties. The eae gene was found in 23 isolates of E. coli from 22 dogs, 19 of 146 (13%) from dogs with diarrhea and 3 of 36 (8.3%) from dogs with no diarrhea. Two different eae+ isolates were recovered from one dog with diarrhea. Isolates from two dogs with diarrhea harbored the bfpA gene, and none of the isolates possessed genes for enterotoxins, the EAF plasmid or Shiga toxins. PCR showed that, among the 23 isolates, eight were positive for beta intimin, six for gamma, two for, one for alpha, one for kappa, and five showed no amplification with any of the nine pairs of specific intimin primers used. PCR also showed that the LEE (locus of enterocyte effacement) was inserted in selC in four isolates, likely in pheU in seven isolates, and in undetermined sites in twelve isolates. Fifteen isolates adhered to HEp-2 cells and were fluorescence actin staining (FAS) positive. The predominant adherence pattern was the localized adherence-like (LAL) pattern. The eae-positive isolates belonged to a wide diversity of serotypes, including O111:H25, O119:H2 and O142:H6, which are serotypes that are common among human EPEC. These results confirmed the presence of EPEC in dogs (DEPEC) with and without diarrhea. The virulence factors found in these strains were similar to those in human EPEC, leading to the possibility that EPEC may move back and forth among human and canine populations.     

Cervical syringohydromyelia secondary to a brainstem tumor in a dog

An 11-year-old male Pekingese was evaluated because of a history of head tilt. Neurologic examination revealed a right-sided head tilt, ataxia, scoliosis, and proprioceptive deficits. Diagnostic testing included magnetic resonance imaging (MRI) of the head and neck. After IV administration of gadopentetate dimeglumine, an extra-axial, highly contrast-enhanced mass in the brainstem, cerebellar herniation, and syringohydromyelia were detected via MRI. The dog was treated with corticosteroids and radiation therapy of the mass for 4 weeks (total dose, 42.5 Gy). Magnetic resonance imaging was repeated 9 weeks and 6 months after radiation therapy; compared with the initial findings, a reduction in the size of the brainstem mass was observed in both MRI scans. The third MRI scan also revealed a normal cerebellar shape, no evidence of herniation, and resolution of syringohydromyelia in the dog at that time. It is recommended that whenever syringohydromyelia is observed via MRI, a primary cause (cranial or caudal to the affected region) should be sought.     

Additive genetic relationships between heifer pregnancy and scrotal circumference in Nellore cattle

To estimate heritability (h2) for yearling heifer pregnancy and to estimate the genetic correlation between heifer pregnancy and scrotal circumference, 18,145 records of Nellore heifers exposed to breeding at an age of approximately 14 mo and 25,466 records of contemporary young bulls were analyzed. Heifer pregnancy was considered as a categorical trait, with the value 1 (success) assigned to heifers that were pregnant after rectal palpation approximately 60 d after the end of a 90-d breeding season and the value 0 (failure) otherwise. A single-trait animal model for heifer pregnancy and a two-trait animal model including heifer pregnancy and scrotal circumference were used. Contemporary groups were defined in two ways: including (CG2) or not including (CG1) weaning management of the heifer. Heritability estimates obtained by Method R in single-trait analyses were 0.68 +/- 0.09 and 0.61 +/- 0.10 using CG1 and CG2 definitions, respectively. Heritability estimates for two-trait analyses were 0.69 +/- 0.09 (CG1) and 0.63 +/- 0.08 (CG2) for heifer pregnancy and 0.57 +/- 0.03 (both CG) for scrotal circumference. The genetic correlation estimates between the two traits were 0.20 +/- 0.12 (CG1) and 0.20 +/- 0.13 (CG2). Based on the results of this study, EPD for heifer pregnancy can be used to select bulls for the production of precocious daughters and will be more effective than selecting on scrotal circumference EPD in Nellore cattle. However, scrotal circumference can be incorporated in a two-trait analysis to increase the accuracy of prediction for heifer pregnancy EPD for young bulls. Using contemporary group without heifer weaning management gave higher h2 and, for two-trait analysis, converged more quickly.     

Preservation of cadavers for surgical technique training

OBJECTIVE: To evaluate a technique for preservation of organoleptic tissue characteristics (color, odor, texture, and flexibility) in cadavers used for surgical instruction. STUDY DESIGN: Experimental study. ANIMALS: Forty-three canine cadavers. METHODS: Cadavers were preserved with a modified Larssen solution of the Hospital Cochim, Paris and cryopreservation. Tissue handling qualities were evaluated in surgical laboratory sessions. RESULTS: All cadavers kept texture and tissues consistency, especially skin and muscle, similar to those of live animals. Some skin desquamation and pallor of the mucous membranes occurred with repetitive freeze-thaw cycles. CONCLUSIONS: This preservation technique provides acceptable cadaver quality and tissue handling for use in surgical instruction. CLINICAL RELEVANCE: Preparation of patient cadavers by intravascular injection of modified Larssen solution yielded suitable instructional models for surgical training.     

Cell proliferation in feline normal, hyperplastic and neoplastic mammary tissue--an immunohistochemical study

The expression of a proliferation cell marker in neoplastic and non-neoplastic mammary tissue in 31 cats was assessed by immunohistochemistry in formalin-fixed paraffin-embedded samples using a monoclonal antibody against nuclear antigen Ki-67 (MIB-1). The results revealed that cell proliferation was more intense in hyperplastic than in normal mammary tissue. Carcinomas exhibited a higher MIB-1 index than benign tumours. There was also a positive correlation between proliferative activity and the histological grade of carcinomas. Fibroadenomatous change, which is considered to be hyperplastic and associated with favourable biological behaviour, exhibited high proliferative activity involving both epithelial and mesenchymal components. MIB-1 detected in formalin-fixed material with pre-treatment with antigen retrieval solution appeared to be a reliable marker of proliferation in feline mammary tumours, but further studies are needed to investigate the value of this proliferation marker in predicting clinical outcome and/or as a prognostic factor in feline mammary lesions.     

Enrofloxacin assay validation and pharmacokinetics following a single oral dose in chickens

The pharmacokinetics of enrofloxacin (ENRO), a fluoroquinolone antimicrobial agent, was studied in male broiler chickens (Cobb) after single oral administration of 10 mg of ENRO/kg b.w. A high-performance liquid chromatography-photodiode array detector (DAD) (HPLC-DAD) method was developed and validated and used for quantitation of ENRO and its major metabolite ciprofloxacin in plasma. The HPLC analyses were carried out using a cationic-octadecyl mixed column and 0.05 mol/L phosphate buffer (pH 2.5)/acetonitrile as mobile phase. The sample preparation of plasma consisted of the precipitation of proteins followed by solid phase extraction on cationic-octadecyl mixed cartridges. The method was validated considering linear range, linearity, selectivity, sensitivity, limit of detection (LOD), limit of quantitation (LOQ), intra- and inter-day precisions and accuracy. The LOD and LOQ for both fluoroquinolones were 60 and 200 ng/mL for plasma. The plasma concentration vs. time graph was characteristic of a two-compartment open model. The maximal plasma concentration of 1.5 +/- 0.2 mg/mL was achieved at 9 +/- 2 h. The elimination half-life and the mean residence time of ENRO were 1.5 +/- 0.2 and 15.64 h, respectively. The area under the concentration-time curve was calculated as 35 +/- 4 mgxh/mL.