Abstract

Salmonellosis caused by non-typhodial Salmonella enterica serotypes is one of the most important food-borne diseases worldwide and biofilm structure formed by these pathogens provide a reservoir for food contamination and a source for infections. This study was performed in order to determine biofilm formation abilities of food borne Salmonella isolates on polystyrene and on air liquid interphase and their colony morphologies when grown on Congo Red Agar plates. 32 food-borne Salmonella strains isolated from retail chicken carcasses in Edirne province of Turkey and belonging to the Infantis, Enteritidis, Kentucky and Telaviv serotypes were used. The microtiter plate technique was used to determine biofilm formation abilities of the isolates on polystyrene surfaces by measuring the optical density (OD) values of the stained bacterial biofilms. The results showed that the strongest biofilm formation capacities of the isolates were observed at 22°C for 3 days of incubation. Although all isolates formed pellicle on the liquid-air interface at 22°C, only 13% of the isolates belonging to the Infantis, Kentucky and Enteritidis serovars formed pellicle at liquid-air interface at 37°C. Three different colony morphotypes (saw; smooth and white, bdar; brown, dry and rough, rdar; red, dry and rough) were determined on Congo Red Agar among the isolates. High biofilm formation abilities of the tested Salmonella isolates can lead to widespread of virulence and resistance properties, especially to medically important antibiotics such as ciprofloxacin, via food chain. This situation constitutes an important concern for public health.