MIHAELA MAGDALENA MITACHE, CARMEN CURUTIU, IRINA GHEORGHE, VERONICA LAZAR, MARCELA BUCUR, CORALIA BLEOTU, DANIEL COCHIOR, ELENA RUSU, CARMEN MARIANA CHIFIRIUC PHENOTYPIC, BIOCHEMICAL AND GENOTYPIC CHARCATERISATION OF SOME FACTORS INVOLVED IN THE VIRULENCE AND SURVIVAL OF BACTERIA ISOLATED FROM FOOD AND FOOD PROCESSING SURFACES Species of the Enterobacteriaceae family are frequently involved in various gastrointestinal infectious diseases, including food poisoning that without proper treatment and medical supervision can be fatal for some patients, particularly for those with weak immune systems. Therefore we proposed to characterize the virulence factors of some strains from the Enterobacteriaceae family isolated from food and food processing surfaces at the phenotypic and genotypic level in order to assess the microbiological risk for the public health. The strains were identified using conventional biochemical methods. The expression of virulence soluble markers and the ability of the enterobacterial strains to adhere to the inert and cellular substrate were investigated. At the genetic level the presence of some genes involved in adhesion and virulence was also investigated by PCR. The tested strains revealed a different adherence capacity to the inert and cellular substrata and also ability to develop biofilms. Regarding enzymatic factors, esculin hydrolysis with the production of esculetin as an iron chelating agent and the casein hydrolysing protease were mostly expressed. The results proved that Enterobacteriaceae strains isolated from food could represent a microbiological risk factor for consumers’ health, contributing also to the setting up of the reservoir virulence and resistance genes.
Keywords: food control, Enterobacteriaceae, virulence genes reservoir, surveillance, public health