5. Conclusions
The principal focus of the research described in this review centers on using a pan-genome-based DNA microarray to subtype Cronobacter strains and to understand the sequence divergence of species-specific alleles. In this context, the microarray will also be just as useful in understanding gene expression or transcriptomics, i.e., understanding the physiology of an organism cultured under specific growth conditions. Using transcriptomics in conjunction with RNA sequencing should provide researchers with valuable insights into the survival strategies used by Cronobacter in powdered infant formula and other dry foods. Additional uses of microarrays would be the interrogation of strains found associated with clinical samples, which will help confirm or identify relevant virulence factors, and such microarrays would also be a useful tool to understand the distribution and prevalence of genes among species and strains. In summary, the FDA Cronobacter microarray is an undeniably powerful tool in the future of food safety and public health against the threat of foodborne illness epidemics caused by Cronobacter. Over the last few decades, Cronobacter contamination of commercial powdered infant formula products has apparently been reduced, but as illustrated by Patrick et al. [4], the occurrence of infections is still an ongoing problem. Furthermore, Farmer recommends that Cronobacter infections be made a reportable disease to the National Notifiable Diseases Surveillance System and he strongly argues that this action be ratified by the Council of State and Territorial Epidemiologists, as is the case for many other serious infectious diseases [35].