Microbial safety is critically important for powdered infant formula (PIF) fed to neonates, with under-developed immune systems. The quality and safety of food products are dictated by those microorganisms found in both raw materials and the built production environment. In this study, a 2-year monitoring program of a production environment was carried out in two PIF factories located in the Republic of Ireland, and the environmental microbiome in different care areas of these sites was studied by using a 16S ribosomal RNA (rRNA)-based sequencing technique. Results highlighted a core microbiome associated with the PIF factory environment containing 24 bacterial genera representing five phyla, with Acinetobacter and Pseudomonas as the predominant genera. In different care areas of the PIF factory, as hygiene standards increased, deciphered changes in microbial community compositions became smaller over time and approached stability, and bacteria dominating the care area became less influenced by the external environment and more by human interactions and raw materials. These observations indicated that the microbial composition can be altered in response to environmental interventions. Genera Cronobacter and Salmonella were observed in trace amounts in the PIF factory environment, and bacterial genera known to be persistent in a stressed environment, such as Acinetobacter, Bacillus, Streptococcus, and Clostridium, were likely to have higher abundances in dry environment-based care areas. To our knowledge, this is the first study to characterize the PIF production environment microbiome using 16S rRNA-based sequencing. This study described the composition and changing trends of the environmental microbial communities in different care areas of the PIF manufacturing facility, and it provided valuable information to support the safer production of PIF in the future.
Keywords: 16S rRNA sequencing; environment; microbiome; next generation sequencing; powdered infant formula.