Microbial quality and prevalence of Salmonella and Listeria in eggs

Document Type : Original Article


1 Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Isfahan University of Medical Sciences (IUMS), Isfahan, Iran

2 Infectious Disease and Tropical Medicine Research Center, IUMS, Isfahan, Iran

3 Department of Microbiology, School of Medicine, IUMS, Isfahan, Iran

4 Food Security Research Center, IUMS, Isfahan, Iran


Aims: This study was undertaken to determine the microbial quality and the prevalence of Salmonella and Listeria in table eggs in Isfahan, Iran. Materials and Methods: A total of 525 samples were randomly collected from various shops in Isfahan, Iran. Microbial quality of eggs evaluated by coliform count and total bacterial viable counts. Also, detection of Listeria and Salmonella in egg contents and on eggs shells was performed. Results: The mean of total viable bacteria and coliform counts in the egg contents were 3.95 × 10 4 CFU/g and 4.94 × 10 3 CFU/g, respectively. Salmonella and Listeria were not found on the shell or content of eggs. Enterobacteriaceae families were found in 357 of 525 (68.28%) and 276 of 525 (52.44%) of egg shell and egg content samples, respectively. Moreover, Pseudomonas aeruginosa was isolated from 175 (33.41%) and 144 (25.37%) of egg shell and egg content, respectively. The isolated Enterobacteriaceae were included: Enterobacter aerogenesEscherichia coliKlebsiella pneumoniaeButtiauxella agrestisCedecea lapageiCedecea davisae and Erwinia herbicolaConclusion: The findings of the present study indicate although Salmonella and Listeria were not found in egg samples; however, there is an urgent need to improve the hygienic level of consumed eggs.


Volume 1, December
December 2012
Pages 16-20
  • Receive Date: 05 February 2023
  • Accept Date: 05 February 2023