Presence of Salmonella in retail grade a eggs determined by the International Organization for Standardization 6579 method and a LightCycler polymerase chain reaction system

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Temelli S., Kahya Demirbilek S., Ata Z., Carlı K. T., Eyigor A. G.

ANKARA UNIVERSITESI VETERINER FAKULTESI DERGISI, vol.62, no.2, pp.125-132, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 62 Issue: 2
  • Publication Date: 2015
  • Doi Number: 10.1501/vetfak_00000020585
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.125-132
  • Keywords: ISO 6579, real-time polymerase chain reaction, retail egg, Salmonella, REAL-TIME PCR, CULTURE METHODS, ANTIMICROBIAL RESISTANCE, SHELL EGGS, PREVALENCE, POULTRY
  • Bursa Uludag University Affiliated: Yes


This study aims to determine the presence of Salmonella in naturally contaminated grade A eggs by the standard culture method International Organization for Standardization Method 6579 (ISO) and a specific real-time PCR system (LightCycler PCR-LCPCR) to complement ISO. A total of 1635 eggs pooled into 101 samples were randomly collected within one year period from 20 different retail markets in Bursa, Turkey, carrying eggs of 16 large egg producers/suppliers of 5 cities with intensive layer production. Preparation of the egg and shell for analyses, Salmonella isolations and identifications, and detections were performed according to ISO 6887-4:2003, ISO 6579 and LCPCR, respectively. Overall Salmonella detection rate by ISO and LCPCR were 15.8 % (16/101) and 46.5 % (47/101), respectively. Out of 101 inner parts, Salmonella was detected in 11 (10.9 %) samples by ISO, and in 31 (30.7 %) samples by LCPCR. Six of 101 shell samples (5.9 %) were found to harbor Salmonella by ISO, while 18 (17.8 %) shells were positive by LCPCR. All isolates were determined as Salmonella enterica subsp. enterica serovar Enteritidis. These findings indicate considerably high Salmonella contamination in retail grade A eggs. This should be under routine monitoring by rapid methods such as PCR, complemented by standard culture to evaluate and assess the significance of risk for public health.