Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Biology and Microbiology

First Advisor

George S. Torrey


Campylobacters are found in the reproductive organs, intestinal tract and oral cavity of man and animals. The organism was first isolated over 75 years ago and Campylobacter jejuni is now recognized as a pathogen of increasing importance, occasionally causing fatal acute and subacute gastrointestinal illness in humans. From 1973 to 1981, C. jejuni was isolated as frequently as Salmonellae and over three times as often as Shigellae from patients with diarrhea. The number of isolations of C. jejuni from feces of patients with diarrhea increases yearly and the number of cases reported are believed to be an underestimation of the actual number of worldwide infections caused by C. jejuni.. Special culture media have been developed that make possible isolation of many C. jejuni isolates at concentrations of <1 cell/ml from milk (62), <1 cell/g of hamburger and <1 cell/g of eviscerated chickens. It is possible that the bacterium dies before samples of the implicated source can be checked for C. jejuni. However, some C. jejuni isolates have survived in raw milk for 21 days, chicken for 14 - days, and beef for 35 days. The average incubation period before an outbreak of C. jejuni is 3.5 days. Thus, at the time an outbreak is reported and a source determined there should still be time to isolate C. jejuni from the source before viable cells are no longer present. There is a need to determine in vitro and in vivo parameters which control the survival and growth of C. jejuni. One approach to this research is to determine if C. jejuni grows in media which are not conventionally sterilized by moist heat. Campylobacter jejuni, degenerates to a non-viable, coccoid form when cultured on autoclaved media.. Amino acids and tricarboxcylic acid cycle intermediates are the only compounds known to be used by C. jejuni as energy sources, so it is important to keep these compounds from becoming altered when culture media are sterilized. Culture media sterilized by gamma irradiation may increase growth rates of fastidious organisms including C. jejuni and subsequently improve isolation of this bacterium from foods. The purpose of this research was to study the growth of C. jejuni in media sterilized by moist heat under pressure (autoclaving ) or by irradiation . If gamma irradiation of media does not destroy media components sensitive to conventional thermal sterilization, its use may make cultivation of fastidious organisms easier thus allowing improved, more frequent isolation of C. jejuni from suspected sources during outbreaks of food borne illnesses.

Library of Congress Subject Headings


Campylobacter infections -- Prevention

Campylobacter infections -- Research




Number of Pages



South Dakota State University