AIMS: To study the occurrence of Cronobacter spp. in foods and to investigate the phenotypic properties of the strains isolated. METHODS AND RESULTS: A total of 53 strains of Cronobacter spp. isolated from 399 food samples were identified using conventional biochemical methods and MALDI-TOF mass spectrometry. Foods of plant origin were the most frequently contaminated samples. No Cronobacter spp. were found in infant milk formula, wheat-based infant food, pasteurized and raw cow milk, mincemeat, chicken, chickpea and potato dumpling powder. The individual species were identified as Cronobacter sakazakii (54·7%), Cronobacter malonaticus (28·4%), Cronobacter dublinensis (7·5%), Cronobacter muytjensii (7·5%) and Cronobacter turicensis (1·9%). Cronobacter sakazakii and C. malonaticus belong to biotype 1, 2, 2a, 3, 4 and 5, 5a, respectively. Cronobacter dublinensis strains were subdivided into biotypes 6 and 12. All strains were resistant to erythromycin and two of them were resistant to both erythromycin and tetracycline. CONCLUSIONS: Cronobacter spp. were isolated from various food samples pre-eminently of plant origin and dried food ingredients. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings will increase and detail our knowledge of the presence and diversity of Cronobacter spp. in foods.

Department of Biochemistry and Microbiology Institute of Chemical Technology Prague Prague Czech Republic

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