In recent years, some outbreaks of bacterial infection in neonatal intensive care units have been traced to powdered infant formula contaminated with Cronobacter species, causing life-threatening diseases such as necrotizing enterocolitis and meningitis. This study for the first time presents growth data and whole genome comparisons for five different species of Cronobacter after the taxonomic revision by Iversen et al. (2008). Growth data for 28 bacterial strains across 21 bacterial species in casein- and whey-dominant infant formula at temperatures 21, 27, 37, 41 and 44oC were determined, covering category A and B organisms as defined by WHO 2006. The data revealed potential of some Cronobacter species to grow at 44oC, posing a significant risk of infection by the bacterium when following the current formula preparation guidelines. The results were presented to the Food Standards Agency with the aim to update the current risk assessment model and improve infant formula preparation guidelines. The first sequenced Cronobacter genome (C. sakazakii BAA-894) was used to construct a 384,030 probe oligonucleotide tiling DNA microarray covering its 4 Mb chromosome and plasmids pESA2 (31 kb) and pESA3 (131 kb). Comparative genomic hybridization (CGH) was undertaken on five C. sakazakii strains, and representatives of four other Cronobacter species. CGH highlighted 15 clusters of genes that were divergent or absent in more than half of the tested strains
