Thesis presented October 10, 2012

Abstract:
The standard protocol for bacterial diagnosis in the medical and agronomic fields remains microbial culture, which takes several days to identify the pathogen. However, these time lags are not compatible with the urgency to rapidly analyze the presence of pathogenic bacteria. There is a strong need to develop new tools for identifying pathogenic bacteria in a shorter time. To achieve this goal, Surface Plasmon Resonance imaging (SPRi) technology has been successfully used for the specific detection of bacterial populations during their growth, using proteins and/or antibodies as bio-recognition molecules targeting bacterial surfaces. Thus, the specific detection of one to thousand pathogens/ml could be achieved within few hours. Several bacterial strains were used as models in this work: Streptococcus pneumoniae R6, Escherichia coli K12, as well as a real pathogen (Salmonella enteritidis) providing the proof that this method can be enlarged to other strains. The results can be quantitative by establishing a calibration curve, allowing extrapolation of the initial concentration of a contaminated sample. The strategy developed in this work, is based on the simultaneous coupling of the bacterial enrichment with the specific detection and identification, using the SPR imaging technique.

Keywords:
Real Time Monitoring, Rapid Diagnosis, Biosensors, SPR Imaging, Pathogenic Bacteria

On-line thesis.