title: Development of a rapid and sensitive method combining a cellulose ester microfilter and a real-time quantitative PCR assay to detect Campylobacter jejuni and Campylobacter coli in 20 liters of drinking water or low-turbidity waters.
abstract: Investigations of Campylobacter jejuni and Campylobacter coli in samples of drinking water suspected of being at the origin of an outbreak very often lead to negative results. One of the reasons for this failure is the small volume of water typically used for detecting these pathogens (10 to 1,000 ml). The efficiencies of three microfilters and different elution procedures were determined using real-time quantitative PCR to propose a procedure allowing detection of Campylobacter in 20 liters of drinking water or low-turbidity water samples. The results showed that more than 80% of the bacteria inoculated in 1 liter of drinking water were retained on each microfilter. An elution with a solution containing 3% beef extract, 0.05 M glycine at pH 9, combined with direct extraction of the bacterial genomes retained on the cellulose ester microfilter, allowed recovery of 87.3% (±22% [standard deviation]) of Campylobacter per 1 liter of tap water. Recoveries obtained from 20-liter volumes of tap water spiked with a C. coli strain were 69.5% (±10.3%) and 78.5% (±15.1%) for 91 CFU and 36 CFU, respectively. Finally, tests performed on eight samples of 20 liters of groundwater collected from an alluvial well used for the production of drinking water revealed the presence of C. jejuni and C. coli genomes, whereas no bacteria were detected with the normative culture method in volumes ranging from 10 to 1,000 ml. In the absence of available epidemiological data and information on bacterial viability, these last results indicate only that the water resource is not protected from contamination by Campylobacter.
authors.affiliation: Agence Nationale de Sécurité Sanitaire, Laboratoire d'Hydrologie de Nancy, Unité Microbiologie des Eaux, Nancy, France.
authors.forename: Adeline
authors.initials: A
authors.lastname: Tissier
authors.forename: Martine
authors.initials: M
authors.lastname: Denis
authors.forename: Philippe
authors.initials: P
authors.lastname: Hartemann
authors.forename: Benoît
authors.initials: B
authors.lastname: Gassilloud
mesh_terms: D058491:Bacterial Load; D001431:Bacteriological Techniques / Q000379:methods*; D017000:Campylobacter coli / Q000302:isolation & purification*; D016123:Campylobacter jejuni / Q000302:isolation & purification*; D060766:Drinking Water / Q000382:microbiology*; D005374:Filtration / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D060766:Drinking Water