Genetic Study of Lactobacillus Strains Colonizing a Murine Gastric Epithelium

My main goal in this project was to develop a system for studying the genetic basis for mechanisms by which Lactobacillus strains colonize the keratinized murine gastric epithelium. Lactobacillus strains from various animal sources were tested for their capacity to colonize that habitat. Only strains isolated from rodents could colonize the gastric surface. The strains were then screened for plasmids. Of 24 tested, twenty strains contained cryotic plasmids that could not be cured by methods used. There was no obvious relationship between the plasmids detected and 3 phenotypes of the bacterial strains (i.e. resistance to antibiotics, deconjugation or bile acids, and colonial morphology). Plasmids of 80-90 Mdal were detected only in strains isolated from mice and able to form layers on the gastric epithelium. DNA-DNA hybridization with one of those large plasmids as probe, and analysis with five restriction endonucleases indicated that these large plasmids belong to at least two groups. DNA sequences homologous to the probing plasmid were detected in six of the strains studied. All of the six contained plasmids of various sizes. Only some of them colonized the keratinized gastric epithelium in monoassociated mice. No apparent relationship exists, however, between any of the plasmids detected and the capacity of the lactobacillus strains to colonize their gastric habitat.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Microbiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Lin, Jane Huey-Chai

• Biology, Microbiology

Identifier

(UMI)AAI8623355

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71178