Purpose: Growth promotion and isolation of Cronobacter spp. and Cronobacter-related species were tested and confirmed with BPW, CSB and CCI agar, as described by EN ISO 22964:2017.
Methods: For growth promotion >15 Cronobacter spp. strains, >10 Franconibacter spp. and 3 Siccibacter spp. strains, including type strains and wild isolates from food, environmental samples and C. sakazakiireference material spiked into the food matrix, were used for evaluating the media from the whole workflow.
Performance testing for the quality assuarance of the culture media for productivity selectivity and specificity were tested, as given by the EN ISO standard.
Results: All Cronobacter spp. and non-Cronobacter strains from pure strains resp. spiked reference material were able to be detected, following the method given by the revised standard: non-selective pre-enrichment in BPW, incubated between 34-38°C for 18 h ± 2h, followed by selective enrichment in CSB, incubated at 41,5 °C ± 1°C for 24 ± 2h and plated out and identified on CCI agar, incubated at 41,5°C ± 1°C for 24 ± 2h. Productivity, selectivity and specificity of the media affected the performance, as specified by the standard.
Significance: For the tested Granucult® BPW, CSB and Chromocult® CCI agar, the results of this study indicate the applicability of the methods and criteria as given in the revised International Standard EN ISO 22964:2017 “Microbiology of the food chain - Horizontal method for the detection of Cronobacter spp.”