Using microsphere or fluorescein tracers and total oocyst output to measure ingestion of material following live-coccidiosis vaccinations.

One method of prevention of coccidiosis in broiler chickens raised without antibiotics relies on coccidiosis vaccination. Live-coccidiosis vaccines carry the risk for pathogenic effects if the Eimeria species overcycle. However, all chicks must receive an appropriate dose of Eimeria oocysts to induce immunity and reduce the risk of adverse effects. At the hatchery, coccidiosis vaccines are administered topically to boxes of chicks by spray or gel-droplet application. Determining the volume of vaccine ingested by individual chicks could provide a means of evaluating the success of different application methods. For each of 2 mass application methods (spray, gel-droplet), we used 3 quantification methodologies to determine the amount of vaccine material ingested by chicks: total oocyst counts from feces collected 5- to 8-days postvaccination; and counts of either microsphere or fluorescein tracers recovered from the gastrointestinal tract 30-min postvaccination. For each quantification methodology, chicks vaccinated via spray or gel-droplet application were compared to chicks vaccinated via oral gavage using the same concentration of oocysts per mL for all groups. Chicks vaccinated via gel-droplet application shed 10-fold more oocysts than those vaccinated by spray application. Individual chick consumption of vaccine material using tracers also revealed that chicks ingested more material following gel-droplet application than spray application, although the magnitude of the difference varied based on quantification methodology. The results of this study suggest that all 3 quantification methodologies can be used to help validate and improve mass vaccine application methods to ensure optimal ingestion, and therefore, coccidiosis vaccination success.

DESCRIPTION OF A NEW EIMERIA SPECIES (APICOMPLEXA: EIMERIIDAE) RESPONSIBLE FOR CLINICAL COCCIDIOSIS IN COMMERCIAL CHUKAR PARTRIDGE (ALECTORIS CHUKAR).

Recurrent coccidiosis affecting a commercial chukar partridge (Alectoris chukar) farm in Ontario, Canada was investigated. The responsible pathogenic Eimeria species was isolated for biological characterization. The uniformity of oocyst morphometrics supported that only a single Eimeria sp. was present. Experimental infections with coccidia-free chukars were used to describe exogenous and endogenous developmental stages of the parasite. The prepatent period of the causative Eimeria species was 5 days and patency lasted 11 days; fecundity was 1,573 to 30,057, with the highest fecundity recorded with the lowest challenge dose. Endogenous development was elucidated histologically from samples collected at 8 locations along the intestinal tract at 26 time points throughout prepatency. The parasite had 5 asexual generations before oocyst formation that were located from the mid-jejunum to the mid-rectum and in the ceca. Sporulation of oocysts suspended in potassium dichromate at room temperature (22 C) occurred within 24 hr. Oocysts (n = 50) averaged 21.8 by 18.6 µm and featured a polar granule; sporocysts (n = 50) averaged 10.9 by 7.1 µm and possessed a Stieda body, sub-Stieda body, sporozoite refractile bodies, and sporocyst residuum. Comparisons with described Eimeria spp. infecting partridges suggest that the biological features of this pathogenic species are unique; similarly, sequences from both mitochondrial and nuclear loci support the naming of this new Eimeria species.

Extended-spectrum cephalosporin resistance in Escherichia coli from broiler chickens raised with or without antibiotics in Ontario, Canada.

Extended-spectrum cephalosporin (ESC)-resistant Escherichia coli were isolated from fecal samples enriched in ESC-containing broth over two years from broiler chickens raised with and without therapeutic antimicrobials. Pooled samples were obtained from 13 different farms in Canada over two rearing cycles each. Resistant isolates were screened for blaCMY, blaCTX-M, and blaSHV by PCR, and several isolates were sequenced and assembled using Oxford Nanopore MinION technology. Flocks raised with or without antimicrobials contained similar ESC-resistant E. coli. Some plasmids were found in isolates from both farm types and many shared replicon types (IncI1, F, C, and B/O/K/Z) and resistance determinants. Although the use of cephalosporins has stopped in poultry production in Canada, the prevalence of ESC-resistant E. coli found in this study remained high; therefore, further studies are required to determine routes of transmission and persistence.

Management of urethral diverticulum complicating hypospadias repair.

BACKGROUND: Urethral diverticula can occur after hypospadias repair, and may lead to stone formation, incomplete voiding, infection, postvoid dribbling, haematuria and other problems. We previously reviewed our experience with hypospadias complications. We separately analyzed those patients who developed urethral diverticula to attempt to identify predisposing factors and appropriate management strategies. PATIENTS AND METHODS: We reviewed the available medical records and charts of 123 patients undergoing re-operation for hypospadias complications at The Children's Mercy Hospital from 1 May 1984 until 1 January 2003. Hypospadias cripples, traumatic fistulae, complications after circumcision and true intersex patients were excluded. RESULTS: Diverticula accounted for 11% of all complications (13 patients). The patients with diverticula were more likely to have perineal/proximal hypospadias. The initial repair was island tube urethroplasty in five, island onlay urethroplasty in seven and bladder mucosal graft in one child. The repair of the diverticulum in one stage was successful in 10 of the 13 patients. There was one recurrent diverticulum and two fistulas. A stricture was present in only one of the 13 patients but was detected overall in 14 of the 123 patients (11%). CONCLUSION: Diverticula are uncommon after hypospadias repair, accounting for 11% of all complications in the present series. The stricture was not causative in 12 of 13 children. Repair of the diverticulum was successful after one attempt in 10 of 13 patients. The management of this complication is discussed.