Groundwaters from chalk aquifers which are used as a supply for drinking water are often contaminated with pesticides ‐ in particular, atrazine. This paper discusses the use of an industrial‐scale ultraviolet chamber to reduce the concentration of atrazine in a chalk‐derived water which is used for drinking water supply. The concentration of atrazine varied between 0.1 μg/l and 0.5 μg/l, and the raw water was spiked when necessary. Results for other pesticides contaminants are also presented.The efficiency of atrazine removal is dependent only on the energy input and is constant, regardless of the initial concentration. Hydrogen peroxide improves the efficiency of ultraviolet irradiation but requires high doses.

Escherichia coli O157:H7 is a common pathogen found in processed beef trimmings and ground beef that has lead to many infectious outbreaks associated with undercooked meat. Only one strain of E. coli is tested for in ground beef, however, legislation is being considered for identifying up to 6 additional strains. We have developed a testing method that uses the Automated Sample Preparation (ASP) instrument, with a multiplexed PCR assay containing HyBeacons, to easily identify three genes in the O157:H7 strain. HyBeacons probes are hybridization probes that simultaneously identify multiple genes via melt curve analysis. In this study, samples of ground beef inoculated with O157:H7, and swabs from inoculated surfaces that had been in contact with ground beef, were cultured at 37°C for 24 hours. Following incubation, 200 μl from each sample was placed into an ASP cartridge for DNA extraction and purification. DNA from each sample was used in a multiplexed PCR assay that identifies stx 1, stx 2, and eae gamma genes of O157:H7. DNA yields from beef culture and swab samples were measured on a NanoDrop (Thermofisher) and yielded an average of 26ng/ul and 17.2 ng/ul respectively. All gene targets were successfully amplified and confirmed via high resolution melt curve analysis. The multiplexed assay would be ideally suited for expansion to include additional O157:H7 genes or even identification of multiple strains of E. coli.

Salmonella enterica is a gram negative bacterium commonly associated with raw poultry and food borne illness. Evogen has developed a fully Automated Sample Preparation (ASP) instrument which was used to extract and purify DNA from ground turkey meat cultures and kitchen surface swabs. DNA purified on the ASP was then amplified using loop‐mediated isothermal amplification (LAMP). Five gram samples of fresh ground turkey were placed in 50 mL of culture media in sterile culture flasks, inoculated with S. enterica at 3800 cfu/mL and placed in a 37°C incubator for 24 hours. Kitchen surfaces which had been in contact with the fresh turkey were inoculated at 3800 cfu/mL and allowed to dry for 30 minutes. Swabs were used to sample surfaces and placed in 1 mL of culture media and cultured at 37°C for 24 hours. Following incubation, a 200 μl aliquot from each sample was placed in an ASP cartridge for DNA extraction and purification. DNA concentration was measured after extraction. 5.0μl of extracted DNA was then used for LAMP. The LAMP reactions were held at 65ºC for 30 minutes and an annealing curve was performed at 98–75ºC. All culture and swab samples extracted on the ASP provided positive results via LAMP within 12 minutes. The mean concentration of DNA recovered from the samples was 21.0 ng/μl ± 2.8 ng/μl. This new sample preparation system provides high quality DNA that was rapidly detectable by LAMP.Private Funding