Rapid quantitative monitoring method for the fish spoilage bacteria Pseudomonas.
Pseudomonas spp. is a group of microorganisms commonly found in fish and other fresh foods and is involved in their spoilage process. The aim of this study was to develop a rapid and accurate quantitative assay for Pseudomonas spp. in fish using real-time PCR. The assay targets the carbamoyl phosphate synthase gene (carA) with SYBR green based real-time PCR. The selectivity of the assay was confirmed using 24 Pseudomonas strains and 55 non-pseudomonad strains. A linear quantification was established over seven orders of magnitude, from 40 - 4(7) copies reaction(-1). The assay was validated on cod samples collected during two shelf life trials and showed a high degree of correlation to the plate count method (rP = 0.891) where the difference between the methods was 0.04 log(10) CFU g(-1) on average. The study shows that it is possible to quantify accurately the specific spoilage organisms belonging to the genus Pseudomonas in fish using real-time PCR. The method takes less than 5 h from sampling to results. The short detection time of the method can provide the fish industry with an important tool for quality control and processing management.
Reynisson
Eyjólfur
E
Matís-Icelandic Food Research, Reykjavík, Iceland. eyjolfur@matis.is
Lauzon
Hélène Liette
HL
Magnusson
Hannes
H
Hreggvidsson
Guethmundur Oli
GO
Marteinsson
Viggó Thor
VT
D001483:Base Sequence; D002138:Calibration; D017931:DNA Primers; D005516:Food Microbiology; D006801:Humans; D016133:Polymerase Chain Reaction; D011549:Pseudomonas / Q000235:genetics / Q000302:isolation & purification*; D012015:Reference Standards; D017747:Seafood / Q000382:microbiology*; D012680:Sensitivity and Specificity
D017931:DNA Primers