Abstract
Cronobacter spp. (formerly Enterobacter sakazakii) has been isolated from a wide range of environmental and several food sources. Cronobacter spp. is an opportunistic pathogen causing serious infection in infants, particularly neonates. The aim of this study was to isolate and characterize Cronobacter spp. from food sources (infant food, herbs and spices and vegetables) and from environmental sources as dust from vacuum cleaners. Isolation of Cronobacter spp. was performed on selective chromogenic agars, fi rstly using commercial ESIA agar and thereafter on Kim and Rhee-KR agar described in the literature. Phenotypic characteristics were obtained by commercial miniaturized biochemical ENTEROTEST 24 kits and the fi nal confi rmation of isolated strains was performed by molecular techniques (PCR, PCR - DGGE analysis, and 16S rDNA sequencing). Altogether, 99 samples were analyzed (47 samples of foods and 52 samples of dust). In total, 43 isolates of presumptive Cronobacter spp. were initially identifi ed, however, only 22 isolates (51%) were identifi ed as Cronobacter spp. with high identity scores (75-99%). The occurrence of presumptive cronobacters in environmental samples was signifi cantly higher than in samples of food (18 out of 52 vs. 4 out of 47; P = 0.003). No cronobacters were found in 17 samples of infant food, 3 isolates originated from herbs and spices, 1 isolate from spinach and 18 isolates from samples of dust (households, restaurants, dormitory rooms). It can be concluded that Cronobacter spp. is a ubiquitous pathogen contaminating food and environment. Cronobacter spp. could be well identifi ed by means of ENTERO24 test kits with high probability. Both phenotypic and genotypic methodology could be used for identifi cation of Cronobacter spp. and they can be combined for reliable identifi cation.