Identification and Biotyping Enterotoxigenic Escherichia coli Strains from Tuna Loins and Flakes Produced in Côte d’Ivoire

Aims: The study aims to explore the enterotoxigenic Escherichia coli (ETEC) strains isolated from tuna loins and flakes produced in Côte d’Ivoire and identify their biotypes.

Study Design: Tuna loins and flakes were obtained from two industries located in Abidjan. Samples of about 500 g frozen tuna were collected in a polyethylene bag and labelled. Samples were stored in an ice box and sent to the laboratory for determination of virulence genes..

Place and Duration of Study: The study was conducted at Central Laboratory for Food Hygiene and Agribusiness, LANADA, Abidjan and Laboratory of Biotechnology and Food Microbiology, Department of Food Science and Technology, University of Nangui Abrogoua Abidjan, Côte d’Ivoire during June 2013 to September 2013.

Methodology: 460 Escherichia coli strains isolates were analysed for the presence of diarrhoea-associated genes (elt and est) by multiplex PCR using specific primers and for the biotyping of ETEC strains based on the characters highlighted with the API 20E gallery.

Results: Forty-four isolates (21 from tuna loins and 23 from tuna flakes) were identified for ETEC, including 22 positive for elt, 8 positive for est and 14 positive for both elt and est. Four biotypes (biotype 1, 2, 3 and 4) were observed in this study. Biotype 2 [LDC (-), ODC (-)] was the most prevalent in the strains with frequencies of 56.8% followed by biotype 1 (31.8%), biotype 3 (6.8%) and biotype 4 (4.5%).

Conclusion: This study revealed the presence of different biotypes diarrhoeagenic E. coli (ETEC) and potential public health risks if tuna products are not properly cooked.