Campylobacter jejuni is a commensal microorganism of the poultry gastrointestinal tract. Broilers, layers, ducks, turkeys, and quails can be colonized by Campylobacter without illness occurring. The vast majority of human Campylobacter infections are recognized as being foodborne. For 2008, preliminary FoodNet data showed that the Campylobacter incidence of infection, 12.68 per 100,000 of the U.S. population, is the second highest, only behind Salmonella at 16.20 per 100,000. To further understand Campylobacter’s role as a foodborne pathogen, analysis at the molecular level is needed. Microbial molecular typing allows for identification and differentiation of bacterial strains beneath the species level. In this study, the “gold standard” method for molecular subtyping, Pulsed Field Gel Electrophoresis (PFGE), along with Diversilab® repetitive element Polymerase Chain Reaction (rep-PCR) and 16S-23S Internal Spacer Region Denaturing Gradient Gel Electrophoresis (ISR DGGE) were used for the molecular typing of Campylobacter jejuni isolates obtained during different stages of commercial broiler production and processing. In addition, the C. jejuni isolates were tested for resistance to antimicrobials commonly used in both veterinary and human medicine. Antimicrobial resistance testing was carried out using a broth dilution system. The majority of recovered isolates came from post-harvest carcass rinsates. Carcass rinses were obtained at post-evisceration, post-chill stages. All isolates (n = 46) were identified by the Polymerase Chain Reaction as Campylobacter jejuni. Three genotypes (n = 44, n = 1, n = 1) were identified by PFGE. The 46 rep-PCR products grouped into seven clusters and two outliers. Clustering of rep-PCR products by sample source was not observed. No relatedness trends were observed for isolates recovered from the same source. The combination of PFGE and Diversilab rep-PCR methods provides highly discriminatory molecular typing results. These results provide practical epidemiological information that shows postevisceration and post-chill stages are still important targets for intervention studies. The very high occurrence of C. jejuni isolates exhibiting genotype A suggests it may differentially express certain gene(s) that enable this strain to more favorably survive under the different harsh environmental conditions encountered during production and processing. In addition, phenotypic testing revealed all of the isolates were not resistant to the antimicrobials azithromycin, ciprofloxacin, erythromycin, gentamycin, tetracycline, florfenicol, nalidixic acid, telithromycin, and clindamycin at any of the concentrations tested. All the C. jejuni isolates exhibited an indistinguishable two-band 16S-23S ISR DGGE profile. Overall, these C. jejuni commercial broiler pre- and post-harvest isolates exhibited an extremely low degree of molecular and phenotypic variability.

One objective of the present investigation was to compare Salmonella and Campylobacter recovery incidence from commercially processed turkeys immediately prior to and following pre-chill and immersion chiller intervention strategies being used in three distinct turkey processing facilities. In each plant, on a single day of processing, 100 carcass rinse samples prior to and following each post-evisceration, pre-chill intervention and following immersion chilling were obtained for Salmonella and Campylobacter recovery. Two of three plants demonstrated a trend of decreased Salmonella on carcasses following the Inside Outside Bird Wash (IOBW), with reductions of 13%, and 11% being observed for Plants 1 and 2, respectively. Results for reductions of Campylobacter contamination were not as straightforward, with only Plant 3 showing decreased levels (11% reduction) following the IOBW. Plant 2 used an additional pre-chill intervention, a low pressure, acetic acid final wash, which was not shown to be effective in causing an additional reduction in either Salmonella or Campylobacter on carcasses. In all three plants, properly managed immersion chilling systems were the most effective microbial intervention for achieving Salmonella andCampylobacter reduction on processed turkey carcasses. While not as effective, the IOBW present in each plant likely contributed to the effectiveness of immersion chiller interventions. If managed properly these intervention points have demonstrated themselves as a viable means to effectively reduce Salmonella and Campylobacter on processed turkeys. Another objective was to modify the scalder environment to an alkaline pH and determine the effects of thermal killing of Salmonella and Campylobacter. In each plant, on a single day of processing, 50 carcass rinse samples prior to and following scald tank immersion and following feather removal were obtained for Salmonella and Campylobacter recovery. Modification of the scald water to alkaline conditions (pH 9- 10) did not result in increased thermal killing of Salmonella or Campylobacter on turkey carcasses, as hypothesized before the investigation. Alkaline conditions are known to facilitate a more efficacious pluck and aid in the detachment of bacteria. Due to this, the bacteria that were recovered at these points on the processing line could have had an impact on the observed data.

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Jan. 7, 2010). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Food Science and Technology, Department of Agricultural, Food and Nutritional Science, University of Alberta." Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 192-231).

Campylobacter is the most commonly reported bacterial cause of gastrointestinal disease in developed countries. Campylobacteriosis is an infectious disease that causes severe diarrhoea, abdominal cramps, vomiting, blood in stools and fever, along with the inability to carry out normal activities for an estimated 3-5 days. Long term sequelae associated with Campylobacter infection includes Guillain Barré syndrome, irritable bowel syndrome and reactive arthritis. The incidence of human campylobacteriosis in the Grampian region was 138.8 per 100,000 people in 2011 which was one of the highest incidence rates within Scotland. Identified areas of limited knowledge in Campylobacter research include: population exposure to risk factors, financial burden and public acceptability of interventions to reduce Campylobacter in the poultry process. This thesis utilises questionnaire methods to gather data from the Grampian population to expand our knowledge in these research areas to assist in the reduction of human campylobacteriosis.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Case-control studies are the traditional ways in which foodborne enteric diseases are studied and outbreaks are investigated. This method has some significant limitations and biases for diseases with low efficiency reporting rates, such as Campylobacter, a common foodborne disease. Case-case methodologies have been explored for these studies but have been implemented without any clear strategy. This dissertation aims to first, determine the common risk factors for Campylobacter in Arizona using the traditional case-control study design, second, to systematically compare case-case studies to the more common case-control studies, and third, to simultaneously compare the results of a community outbreak of Campylobacter using both case-control and case-case study designs. Results from these studies identified some unique risk factors for routine Campylobacter infection in Arizona that will be used to enhance surveillance for the disease in the state. A systematic review of case-case studies used for enteric diseases found that there are specific recommendations that can be put into place in determining what comparison cases should be selected based on the primary aims and goals of the study. Finally, the results of the simultaneous case-case and case-control studies of a Campylobacter outbreak showed that these methods may work best in conjunction with one another and in doing so, the most accurate depiction of the source of infection can be determined.

Infectious disease continues to cause significant problems on reproductive efficiency in the cattle industry. The purpose of this project is to evaluate new testing strategies for Tritrichomonas foetus and Campylobacter fetus subsp. venerealis. This thesis describes the result of three studies that evaluated the use of real-time PCR for the identification of Tritrichomonas foetus and Campylobacter fetus subsp. venerealis in carrier bulls. The first study evaluated the specificity of a real-time PCR test for T. foetus in individual culture enriched samples, and the sensitivity of the assay for use in pooled samples of up to 25 bulls. Specificity estimates were 98.8% (95% CI 97-99.4) and 100% (95% CI 98.9-100) for culture and real-time PCR, respectively. The sensitivity of the real-time PCR assay for pooled preputial samples was: 96.8% (83.8-99.4) for pool ratios 1/3 and 1/5; 93.5% (79.3-98.2) for pool ratios 1/2, 1/15, 1/20 and 1/25; and 90.3% (75.1-96.6), and were not significantly different. However, 13 of the 217 pools tested were negative and 9 of these negative testing pools contained the same positive sample. The media in this positive sample showed evidence of contamination and could potentially explain the failure to detect T. foetus. The second study evaluated the sensitivity of a real-time PCR for the detection of T. foetus in individual and pooled direct preputial samples. Sensitivity of individual samples tested by culture, real-time PCR in direct and culture enriched samples were determined from 121 samples obtained from 9 infected bulls. Sensitivity estimates were: 95.0% (95% CI: 89.6% to 97.7%) for culture, 95.9% (95% CI: 90.7 to 98.2) for real-time PCR in cultured enriched samples, and 90.1% (95% CI: 83.5 to 94.2) for direct preputial samples and did not differ (P=0.12). Sensitivity estimates for direct pooled samples in groups of 5 or 10 were: 83.6% (95% CI: 75.6 to 89.4) and 77.3% (95% CI: 68.6-84.1), respectively and were not significantly different (P=0.08). The use of repeat sampling tested in pools by real-time PCR increased the sensitivity to 100% and 96% for 3 consecutive samples (pools of 5 or 10, respectively). The use of pooled direct preputial samples although sensitive, still requires the use of repeated sampling. The third study determined the sensitivity and specificity of a recently developed real-time PCR (qPCR) tests for Cfv. A total of 300 virgin bulls were tested by both culture and qPCR. Specificity estimates were 85% (95% CI: 80.5 to 88.6) for qPCR and 100% (95% CI: 98.7 to 100) for culture, and were significantly different (P<0.01). A total of 4 naturally infected bulls and 9 artificially infected bulls were sampled serially to obtain positive samples for a sensitivity analysis. Sensitivity estimates and 95% confidence intervals are as follows: qPCR (85.4%, 95% CI: 80.6-89.2); direct culture on blood agar (82.3%, 95% CI: 77.2-86.5), DFAT (72.1%, 95% CI: 66.2-77.4), direct culture on Skirrow agar (32.7%, 95% CI: 27.2-38.7), TEM and blood agar (30%, 95% CI: 23.4-37.5), and TEM and Skirrow agar (38.1%, 95% CI: 31-45.9). The sensitivity of the different tests evaluated varied significantly with different ambient temperatures (P<0.01). The sensitivity of the qPCR was significantly higher than any other test when temperatures exceeded 5°C. The use of repeated sampling at weekly intervals significantly improved the sensitivity of the qPCR. The real-time PCR assay for the detection of T. foetus in both individual and pooled samples appears to be highly sensitive and specific. Moreover, the possibility of using direct preputial samples provides a cost-effective diagnostic strategy. Real-time PCR in direct preputial samples for BGC diagnosis in bulls has good sensitivity and specificity. However, the use of repeated sampling maybe needed in order to maximize the ability to detect carrier bulls.

Campylobacter jejuni bacterial pathogen is among the primary causes of food-borne acute gastroenteritis in North America and the world. It has also been linked to severe post-infection sequelae such as Guillain-Barré syndrome. Previous studies identified C. jejuni surface capsular polysaccharide (CPS) as a target for creation of a carbohydrate based vaccine in which the CPS is conjugated to a carrier protein. In this thesis, following sample purification, aspects of C. jejuni HS:5 CPS structure were characterized using numerous analytical techniques such as NMR and GC-MS. CPS is comprised of α-DD-Heptoses linked at C2 to the anomeric carbons of glucose. The α-Glucose molecules are linked though C4 to the α-DD-Heptose anomeric carbon. The α-DD-Heptose structure also has an occasional ring structured amino acid modification. Following characterization the CPS was oxidized and developed into a prototype glycoconjugate vaccine using TEMPO oxidation and EDC-CRM197 coupling methods. / The Natural Sciences and Engineering Research Council of Canada (NSERC)

The sub-therapeutic use of antibiotics for growth promotion in food animal production, has engendered substantial debate on the dissemination of antibiotic resistance via the food chain, specifically, the probability of antibiotic use in food production creating a reservoir of resistant bacteria and/or resistance genes that may spread to humans thereby limiting the therapeutic value of antimicrobial drugs. In the absence of any surveillance programme on food-borne bacteria in South Africa, this study focussed on Campylobacter spp. in poultry and encompassed a literature review on the prevailing debate on the dissemination of antibiotic resistance via the food chain, a phenotypic observational study on the prevalence and antibiotic resistance profiles of Campylobacter spp. isolated within and across different poultry farming systems and a genotypic component that covered identification methods, plasmid profile determination and strain typing. Identification methods for Campylobacter spp., viz, biochemical tests and matrix assisted laser desorption ionization- time of flight (MALDI-TOF) mass spectrometry was compared to the PCR which is considered the gold standard as a molecular method of identification. The MALDI-TOF was shown to be superior to the biochemical tests for the identification of C. coli but equivalent to the biochemical tests for C. jejuni. Of the 363 samples collected in total, the frequency of thermophilic Campylobacter was 68 % in rural farms (or informally reared poultry), 47 % in both commercial free-range and industrial broilers and the highest in industrial layers at 94 %. Antibiotic resistance analysis showed that isolates from the rural farming systems were significantly (P < 0.01) more susceptible to ciprofloxacin, tetracycline and erythromycin when compared to the other farming systems. Significant (P < 0.001) antibiotic resistance differences were detected between broilers (5 - 8 week lifespan), and layers (36 - 52 week lifespan) for gentamicin, ciprofioxacin and tetracycline. Plasmids were fonnd be harboured by isolates in all the farming systems; in 84 % of isolates from free-range broilers, 77 % of isolates from industrial broilers, 83 % of isolates from industrial layer hens and 75 % of isolates from the rural farming system. The PFGE genotyping of 42 Campylobacter isolates generated 39 SmaI types. Substantial and substantive genetic diversity was observed between and within farming systems. The lack of correlations amongst the parameters within and between farming systems attested to the diversity and complexity of phenotypes and genotypes and indicated de novo evolution in response to antibiotic selection pressure and animal husbandry practices. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2013.