Master of Science

Abstract

thesisCampylobacteriosis is a foodborne and waterborne zoonotic gastrointestinal illness and the most common cause of acute gastroenteritis worldwide. In the United States Campylobacter infections are second only to Salmonella as the most common cause of gastroenteritis, accounting for an estimated 2.4 million symptomatic infections annually. It is estimated that the total cost of foodborne illness in the United States is $152 billion of which$18.8 billion is attributed to Campylobacter. Diagnosis can be challenging because the organism is difficult to isolate, grow, and identify. Clinical manifestation of Campylobacter is indistinguishable from other enteric pathogens; (Salmonella, Shigella, Yersinia, Clostridium difficile, and E. coli 0157:H7 and other enterohemorrhagic E. coli) therefore, a presumptive diagnosis cannot be made putting them at risk for untreated infection. There are a growing number of diagnostic methods available for detection and/or isolation of Campylobacter species from stool, but there is currently no national or state public health testing guidelines. Eight assays were evaluated for performance in the detection of Campylobacter species in stool. The assays are comprised of four culture medias (CVA, CSM, Cefex, and mCCDA); three EIA/ELISA kits (ImmunoCard STAT! Campy, Premier Campy and ProSpecT Campy); and one molecular method (FilmArray GI panel). The FilmArray GI panel due to its ability to detect viable and nonviable organism was used as the gold standard. To verify the gold standard was accurate all positive FilmArray samples were analyzed by DNA sequencing. The sensitivity and specificity, respectively, of each assay are as follows: CVA 87.8%, 100%; CSM 87.8%, 100%; Cefex 87.8%, 100%; mCCDA 78.0%, 100%; ImmunoCard STAT! Campy 31.7%, 65.2%; Premier Campy 80.5%, 26.1%; and the ProSpecT Campy 75.6%, 82.6%. In contrast the FilmArray produces a sensitivity and specificity of 100% when compared to culture. Furthermore the FilmArray GI panel takes the least amount of time to produce a result, 1 hour compared to 48-72 hours for culture. In conclusion, the FilmArray GI panel is the most sensitive, specific, rapid, cost effective, and objective method for the detection of Campylobacter species in stool. Molecular assays such as the FilmArray GI panel should replace traditional culture techniques in the microbiology lab