title: The species accuracy of the Most Probable Number (MPN) European Union reference method for enumeration of Escherichia coli in marine bivalves.
abstract: Continuous European Union programmes with specified methods for enumeration of Escherichia coli in bivalves for human consumption are currently running. The objective of this research was to examine the species accuracy of the five times three tube Most Probable Number (MPN) EU reference method used for detection of E. coli in marine bivalves. Among 549 samples of bivalves harvested from Norwegian localities during 2014 and 2015, a total number of 200 bacterial isolates were prepared from randomly selected culture-positive bivalves. These presumptive E. coli isolates were characterized biochemically by the Analytical Profile Index (API) 20E, as well as by Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). The majority of isolates (90%) were identified as E. coli, by both API 20E and MALDI-TOF MS. Ten isolates (5%) were identified as Klebsiella pneumoniae, while one isolate was identified as K. oxytoca by both methods, whereas three isolates were identified as Acinetobacter baumannii, Citrobacter braakii, and Enterobacter cloacae, respectively. The identification of the remaining six isolates were not in compliance between the two methods.
authors.affiliation: National Institute of Nutrition and Seafood Research, P.O. Box 2029, Nordnes, 5817 Bergen, Norway.
authors.forename: Didrik Hjertaker
authors.initials: DH
authors.lastname: Grevskott
authors.affiliation: National Institute of Nutrition and Seafood Research, P.O. Box 2029, Nordnes, 5817 Bergen, Norway.
authors.forename: Cecilie Smith
authors.initials: CS
authors.lastname: Svanevik
authors.affiliation: Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, N-0403 Oslo, Norway.
authors.forename: Astrid Louise
authors.initials: AL
authors.lastname: Wester
authors.affiliation: National Institute of Nutrition and Seafood Research, P.O. Box 2029, Nordnes, 5817 Bergen, Norway. Electronic address: blu@nifes.no.
authors.forename: Bjørn Tore
authors.initials: BT
authors.lastname: Lunestad
mesh_terms: D040981:Acinetobacter baumannii / Q000302:isolation & purification; D000818:Animals; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification; D015373:Bacterial Typing Techniques / Q000379:methods*; D049872:Bivalvia / Q000382:microbiology*; D002954:Citrobacter / Q000302:isolation & purification; D004926:Escherichia coli / Q000145:classification* / Q000302:isolation & purification*; D005062:European Union; D059022:Food Safety / Q000379:methods; D006801:Humans; D041121:Klebsiella oxytoca / Q000302:isolation & purification; D007711:Klebsiella pneumoniae / Q000302:isolation & purification; D009664:Norway; D017747:Seafood / Q000382:microbiology*; D012680:Sensitivity and Specificity; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
keywords: API 20E; Bivalve molluscs; Enterobacteriaceae; Escherichia coli; MALDI-TOF MS; MPN