Assessment of the pathogenicity of Campylobacter jejuni from broiler chickens

Persistent Link:
http://hdl.handle.net/10150/282899
Title:
Assessment of the pathogenicity of Campylobacter jejuni from broiler chickens
Author:
Law, Bibiana Felicity
Issue Date:
2005
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Sixty-three of 435 (14.5%) samples collected from broiler chickens were positive for C. jejuni. Twenty-two of 55 samples were from organic chickens (40%) and 41 of 380 samples were from conventional chickens (10.8%). Isolates were subjected to macrorestriction profiling using SmaI and analyzed for their ability to survive in macrophage cells and invade in epithelial cells. Antibiotic testing to cefaclor, ciprofloxacin, tetracycline, erythromycin, gentamicin, trimethroprim/sulfamethoxazole, and ampicillin were performed. Finally, 5 isolates of varying putative in vitro virulence traits were chosen for experimental inoculation of newborn piglets. Five piglets per isolate were tested and examined macroscopically and microscopically upon necropsy. Genotyping of isolates indicated 1 to 3 profiles per flock. Of the 22 organic isolates from chickens, only 3 (13.6%) were able to survive within macrophages. For the conventional isolates, 21 out of 41 (51.2%) were able to survive. However, the majority of isolates (90.5%) from both organic and conventional isolates were not capable of invading epithelial cells. No isolates exhibited resistance to ciprofloxacin or gentamicin. One isolate out of 63 (1.6%) was resistant to erythromycin, 52 (82.5%) to tetracycline, 28 (44.4%) to trimethroprim/sulfamethoxazole, and 6 (9.5%) to cefaclor. In terms of the piglet studies, regardless of the combination of in vitro invasion or survival results or type of flock, most piglets (16/25) in all groups exhibited hyperemia, edema, and hemorrhage in the small intestine or colon upon gross examination. Microscopic examination revealed congested mucosa and erosion of the epithelium in 10 of the 25 piglets from 4 of the 5 groups. In conclusion, this study suggests that C. jejuni isolated from broiler chickens are virulent in piglets and are probably capable of causing disease in humans. Furthermore, the results of the survival and invasion assays did not correlate with the results of the piglet studies and cannot be relied upon to predict degree of virulence. Therefore, another virulence factor is responsible for the pathogenesis, such as a toxin(s). As this is the first study to confirm putative in vitro virulence traits with an animal model, further research is recommended with the piglet model to assess pathogenicity.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Biology, Microbiology.; Environmental Sciences.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Soil, Water and Environmental Science
Degree Grantor:
University of Arizona
Advisor:
Gerba, Charles P.; Joens, Lynn A.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleAssessment of the pathogenicity of Campylobacter jejuni from broiler chickensen_US
dc.creatorLaw, Bibiana Felicityen_US
dc.contributor.authorLaw, Bibiana Felicityen_US
dc.date.issued2005en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractSixty-three of 435 (14.5%) samples collected from broiler chickens were positive for C. jejuni. Twenty-two of 55 samples were from organic chickens (40%) and 41 of 380 samples were from conventional chickens (10.8%). Isolates were subjected to macrorestriction profiling using SmaI and analyzed for their ability to survive in macrophage cells and invade in epithelial cells. Antibiotic testing to cefaclor, ciprofloxacin, tetracycline, erythromycin, gentamicin, trimethroprim/sulfamethoxazole, and ampicillin were performed. Finally, 5 isolates of varying putative in vitro virulence traits were chosen for experimental inoculation of newborn piglets. Five piglets per isolate were tested and examined macroscopically and microscopically upon necropsy. Genotyping of isolates indicated 1 to 3 profiles per flock. Of the 22 organic isolates from chickens, only 3 (13.6%) were able to survive within macrophages. For the conventional isolates, 21 out of 41 (51.2%) were able to survive. However, the majority of isolates (90.5%) from both organic and conventional isolates were not capable of invading epithelial cells. No isolates exhibited resistance to ciprofloxacin or gentamicin. One isolate out of 63 (1.6%) was resistant to erythromycin, 52 (82.5%) to tetracycline, 28 (44.4%) to trimethroprim/sulfamethoxazole, and 6 (9.5%) to cefaclor. In terms of the piglet studies, regardless of the combination of in vitro invasion or survival results or type of flock, most piglets (16/25) in all groups exhibited hyperemia, edema, and hemorrhage in the small intestine or colon upon gross examination. Microscopic examination revealed congested mucosa and erosion of the epithelium in 10 of the 25 piglets from 4 of the 5 groups. In conclusion, this study suggests that C. jejuni isolated from broiler chickens are virulent in piglets and are probably capable of causing disease in humans. Furthermore, the results of the survival and invasion assays did not correlate with the results of the piglet studies and cannot be relied upon to predict degree of virulence. Therefore, another virulence factor is responsible for the pathogenesis, such as a toxin(s). As this is the first study to confirm putative in vitro virulence traits with an animal model, further research is recommended with the piglet model to assess pathogenicity.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectBiology, Microbiology.en_US
dc.subjectEnvironmental Sciences.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineSoil, Water and Environmental Scienceen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorGerba, Charles P.en_US
dc.contributor.advisorJoens, Lynn A.en_US
dc.identifier.proquest3177541en_US
dc.identifier.bibrecord.b49001127en_US
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