Microbiological Quality of Powdered Infant Formula in Latin America

Cronobacter is a bacterial genus that includes seven species, and the species Cronobacter sakazakiiis most related tomeningitis and septicemia in infants associated with powdered infant formula (PIF). The objectives of this study were to evaluate the presence of C. sakazakii and to determine the microbiological quality of PIF for infant consumption. To do this, a total of 128 PIF samples were analyzed in four brands and countries (Chile, Mexico, Holland, and Brazil), considering three types of PIF: premature (PIF1), infant (PIF2), and follow-up (PIF3). Aerobic plate counts (APC) and Enterobacteriaceae (ENT)were assessed in accordance with Chilean official standards. The outer membrane protein A (ompA) gene was amplified to detect Cronobacter spp. and the fus Agene was amplified to identify C. sakazakii by using the Pub MLST Web site and BLAST (NCBI).The antibiotic resistance profile was performed according to the Clinical and Laboratory Standards Institute standards. The pathogen was quantified by the most probable number (MPN). The results showed that APC median values for PIF1, PIF2, and PIF3 were 3.2, 4.9, and 4.8 log CFU g-1, respectively. The APC were higher in PIF2 (P,0.01) from Holland (P,0.01) in the commercial brand 4 (P,0.01). The ENT median values in PIF1, PIF2, and PIF3 were 1.8, 1.5, and 1.7 log CFU g-1, respectively. Five strains of C. sakazakii and one strain of C ronobacter malonaticus were identified as having values between0.023 and 2.3 MPN/g. All strains (100%) harbored the omp A, plasminogen activator (cpa), and hemolys in (hly) virulence genes.To conclude,C. sakazakii was found in four PIF samples from four Chilean products and one from Mexico, which is distributed throughout America.C. sakazakii strains exhibit virulence factors and resistance to ampicillin, thus posing a risk when PIFs are consumed by infants.