MULTIPLEX PCR DETECTION OF HAEMOLYSIN GENES IN β-HAEMOLYTIC AEROMONAS HYDROPHILA STRAINS ISOLATED FROM FISH AND FISH PRODUCTS

I. Vashin, D. Stratev, H. Daskalov, E. Gurova

Abstract: The goal of this study was to establish the presence of genes coding aerolysin (aerA) and haemolysin (ahh1) in β-haemolytic Aeromonas hydrophila strains isolated from fish and fish products available for human consumption throughout food stores. Aerolysin and haemolysin are viewed as important virulence factors related to the enterotoxigenicity of A. hydrophila. A multiplex PCR was applied to 26 β-haemolytic A. hydrophila strains isolated from live carp, water, cooled horse mackerel, trout, silver carp cutlets, vacuum-packed trout filets and frozen trout. The study used a reference A. hydrophila strain (ATCC 7965)
and an A. hydrophila strain isolated from a dead anaconda, as positive controls with strong β-haemolytic activity. All strains (100%) possessed the chromosome gene 16S rRNA (356 bp) specific for A. hydrophila. In all (100%) A. hydrophila strains the gene ahh1 was present (130 bp). The gene aerA was confirmed (309 bp) in 26 A. hydrophila strains (93%). The presence of β-haemolytic A. hydrophila strains in fish and fish products available for human consumption throughout food stores represent a risk to the consumer’s health.

Keywords: A. hydrophila; aerolysin; haemolysin; PCR; β-haemolysis

Date published: 2017-08-28