Are and Isolated from Powdered Infant Formula a Hazard for Infants? A Genomic Analysis.

Powdered infant formulas (PIF) are the most used dietary substitutes that are used in order to supplement breastfeeding. However, PIF are not sterile and can be contaminated with different microorganisms. The objective of this study was to genomically characterize (ENT) and strains that were isolated from PIF. Strains were identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and whole-genome sequencing (WGS). Genomic typing, detection of virulence, and resistance profiles and genes were performed with the Ridom SeqSphere+ software; the comprehensive antibiotic resistance database (CARD) platform; ResFinder and PlasmidFinder tools; and by the disk diffusion method. Nineteen isolates from PIF were analyzed, including ENT such as , , , , and lactic acid bacteria such as . The strains exhibited resistance to beta-lactams, cephalosporins, and macrolides. Resistance genes such as , , , , , , , , , and ; and virulence genes such as , , , , , , , and , were also detected. All the analyzed strains possessed genes that produced heat-shock proteins, such as IbpA and ClpL. In PIF, the presence of ENT and that are multiresistant to antibiotics-together with resistance and virulence genes-pose a health risk for infants consuming these food products.