Identification of a new source of Campylobacter contamination in poultry: transmission from breeder hens to broiler chickens

Campylobacter jejuni, a foodborne pathogen closely associated with market poultry, is considered to be the most frequent agent of human gastroenteritis in the United States. The pathways involved in the contamination of poultry flocks, vertical transmission and/or horizontal transmission, are unclear. In this study, Campylobacter isolates from two independent commercial broiler breeder flocks, as well as from their respective progeny, were characterized and compared by PstI ribotype analysis and by DNA sequence analysis of the short variable region (SVR) of the flaA gene (flaA SVR). Campylobacter isolates originating from one set of breeder hens and the feces from their respective progeny demonstrated identical ribotype patterns as well as identical flaA SVR DNA sequences, thereby suggesting that these isolates were clonal in origin. Ribotype analysis of Campylobacter isolates from the second set of breeder hens and processed carcasses from their offspring resulted in two patterns. Sequence analysis placed these isolates into two closely related groups and one distant group, similar to the ribotype analysis. These results demonstrate that Campylobacter isolates from commercial broiler breeder flocks and from the respective broiler progeny may be of clonal origin and that breeder hens can serve as a source for Campylobacter contamination in poultry flocks.     

Serum complement activity in the three-toed amphiuma (Amphiuma tridactylum)

Some animals routinely endure serious injuries from predators or during intraspecific territorial conflicts. Such is the case for Amphiuma tridactylum, an aquatic salamander that lives in an environment rich in potentially infectious microbes, apparently with rare or no pathogenic infection. Some vertebrates possess innate immune mechanisms, but whether this is the case for Amphiuma is unknown. To assess this potential, plasma from 19 A. tridactylum was pooled and used for characterisation of serum complement activity. The ability of A. tridactylum plasma to hemolyse unsensitised sheep red blood cells (SRBCs) was titer-dependent, with low activity observed even at high plasma titers. The kinetic characterisation of SRBC hemolysis revealed that significant activity could be measured within 10 min of incubation, and maximal activity occurred within 60 min. The SRBC hemolysis by A. tridactylum plasma was also temperature-dependent, with maximal activity at 30 °C. In addition, this activity was sensitive to mild heat treatment, with 96% of activity inhibited by incubation at 56 °C for 30 min. The SRBC hemolysis could also be inactivated by pretreatment of the plasma with proteases, indicating that this activity was protein dependent. The activity required divalent metals ions, with activity inhibited by EDTA, citrate, or phosphate. However, the chelator-inhibited activity could be restored by the addition of excess Ca²⁺ or Mg²⁺, but not Cu²⁺ or Ba²⁺, indicating specificity of the divalent metal ion requirement. The sensitivity to heat, proteases, and divalent metal ion chelators strongly suggests that A. tridactylum plasma-mediated hemolysis of SRBCs is mediated by the serum complement system of proteins.     

Clinical effects of short-term oral budesonide on the hypothalamic-pituitary-adrenal axis in dogs with inflammatory bowel disease

Six dogs were entered into a 30-day, prospective, nonrandomized, uncontrolled clinical trial evaluating the effects of an oral preparation of budesonide on the hypothalamic-pituitary-adrenal (HPA) axis during therapeutic management of active inflammatory bowel disease. Oral budesonide, at a dose of 3 mg/m(2), was administered once daily. Upon entry and completion of the trial, serum basal cortisol, adrenocorticotropic (ACTH)-stimulated cortisol, endogenous ACTH concentration, serum alkaline phosphatase (SAP) activity, and urine specific gravity were evaluated, as well as owner assessment of glucocorticoid-associated side effects. Significant suppression of the HPA axis occurred. No significant differences in SAP activity, urine specific gravity, or owner-subjective assessments were detected.     

Efficacy of famotidine for the prevention of exercise-induced gastritis in racing Alaskan sled dogs

BACKGROUND: Omeprazole reduces the severity of exercise-induced gastritis but not the prevalence of gastric lesions in sled dogs. The frequent feeding of sled dogs during competition likely results in decreased absorption of omeprazole and, thereby, decreased efficacy. HYPOTHESIS: Famotidine, a histamine-2 blocker with good bioavailability in the presence of food, would reduce the incidence and severity of exercise-induced gastric disease in sled dogs. ANIMALS: Sixteen fit Alaskan sled dogs (4 female, 12 male, all intact, age 2-6 years). METHODS: Dogs were randomly assigned to treatment (22 mg famotidine PO q24h) or control groups (n = 8 per group). Famotidine was administered with a meal to the treatment group once daily for 7 days before a challenge and once during exercise. Control dogs were fed an identical diet as the principal group. The 16 dog team completed a 100-mile exercise challenge in 18 hours. A gastroscopy was performed 24 hours after the challenge. The appearance of the mucosa was scored by an individual by using a scoring system. RESULTS: Treatment with famotidine significantly reduced the severity score compared with control (P = .0004). No adverse effects of treatment were reported. CONCLUSIONS AND CLINICAL RELEVANCE: Famotidine is effective in reducing the severity of exercise-induced gastric disease in racing Alaskan sled dogs, with minimal to no adverse effects, and may be recommended for prophylactic use in short distance races.     

Serum chemistry alterations in Alaskan sled dogs during five successive days of prolonged endurance exercise

OBJECTIVE: To determine the impact of successive days of endurance exercise on select serum chemistry values in conditioned Alaskan sled dogs. DESIGN: Prospective cohort study. ANIMALS: 10 conditioned Alaskan sled dogs. PROCEDURES: All dogs ran 160 km/d for 5 consecutive days. Serum was obtained prior to exercise and immediately after each exercise run; all samples were obtained before dogs were fed. Serum electrolyte, mineral, protein, total bilirubin, urea nitrogen, creatinine, and cardiac troponin-I concentrations and serum alkaline phosphatase, alanine aminotransferase, creatine kinase, and aspartate aminotransferase activities were measured. Data were analyzed by means of analysis of covariance for a randomized complete block design with dog as a blocking variable, time as a covariate, and distance run as the treatment of interest. Least square mean values were compared with values obtained prior to exercise, and linear and quadratic contrasts were examined. RESULTS: Serum globulin concentration was low prior to exercise (mean +/- SD, 2.2 +/- 0.3g/dL) and progressively decreased as exercise continued. Exercise was associated with increases in serum chloride, urea nitrogen, and cardiac troponin-I concentrations and serum alanine aminotransferase, creatine kinase, and aspartate aminotransferase activities and with progressive decreases in serum potassium, total protein, and albumin concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that multiple successive days of endurance exercise resulted in mild aberrations in serum chemistry variables in conditioned sled dogs. Changes likely reflected the metabolic stresses of prolonged endurance exercise as well as dietary composition. Hypoglobulinemia in resting, conditioned sled dogs may reflect the immunosuppressive or catabolic effects of intense endurance training.     

Improving response rates: introducing an anonymous longitudinal survey research protocol for veterinary medical students

With the Journal of Veterinary Medical Education's recent summer 2005 theme issue on stress, the mental-health concerns of veterinary medical students has been brought to the forefront of the field. Since it is anticipated that research on this topic will continue and that educational institutions may implement changes based upon these results, it is of the utmost importance that this research be of the highest quality. Of particular concern with human-subject inquiries are response rates and confidentiality. In order to accommodate these concerns, an example of a survey research protocol that promotes high response rates and minimizes threats to internal validity influenced by student mistrust in assurances of confidentiality is presented. Specifically, the protocol is designed to ensure anonymity and to preserve the ability to track students longitudinally through the use of anonymous longitudinal identifiers. This protocol was tested with the first-year class of veterinary medical students at Kansas State University in October 2004 and March 2005. The two data collection periods yielded 90% and 76% response rates, respectively. The matching rate of participants, according to the anonymous longitudinal identifiers from Time 1 to Time 2, was 88%.