Investigation of Conditions for Capture of Live Legionella pneumophila with Polyclonal and Recombinant Antibodies

International audienceSince Legionella pneumophila has caused punctual epidemics through various water systems, the need for a biosensor for fast and accurate detection of pathogenic bacteria in industrial and environmental water has increased. In this report, we evaluated conditions for the capture of live L. pneumophila on a surface by polyclonal antibodies (pAb) and recombinant antibodies (recAb) targeting the bacterial lipopolysaccharide. Using immunoassay and PCR quantification, we demonstrated that, when exposed to live L. pneumophila in PBS or in a mixture containing other non-target bacteria, recAb captured one third fewer L. pneumophila than pAb, but with a 40% lower standard deviation, even when using the same batch of pAb. The presence of other bacteria did not interfere with capture nor increase background by either Ab. Increased reproducibility, as manifested by low standard deviation, is a characteristic that is coveted for biosensing. Hence, the recAb provided a better choice for immune adhesion in biosensors even though it was slightly less sensitive than pAb. Polyclonal or recombinant antibodies can specifically capture large targets such as whole bacteria, and this opens the door to multiple biosensor approaches where any of the components of the bacteria can then be measured for detection or characterisation

New Approaches to Enforcement and Compliance with Labour Regulatory Standards: The Case of Ontario, Canada

This report maps current enforcement and compliance measures and practices in Ontario’s regulation of employment, particularly as they relate to precarious employment. It evaluates the effectiveness of Ontario’s enforcement regimes, focusing on Employment Standards (ES) and Occupational Health and Safety (OHS) legislation, and sets these regimes in the context of those operating in jurisdictions across and outside Canada. Through this process, it identifies and evaluates potential reforms to improve regulatory effectiveness, particularly for workers in precarious jobs. The central argument is that there are fundamental deficiencies in both of these enforcement regimes: each, albeit in different ways, is out of step with the realities of the contemporary labour market and each demands more proactive approaches to regulation combined with, where appropriate, innovative reactive and voluntary measures that are embedded in strong public enforcement