Role of Households with Children in Community Spread of Multidrug-Resistant Enterobacterales, St. Louis, Missouri, USA.

Community-acquired multidrug-resistant (MDR) Enterobacterales bacteria are an increasing public health concern, yet whether households play a role in community spread remains unclear. We investigated 150 households with children in St. Louis, Missouri, USA, for MDR Enterobacterales. We cultured swab specimens from household members and environmental surfaces for identification and antimicrobial susceptibility testing. We also performed whole-genome sequencing in the 53 (35%) households where >1 MDR Enterobacterales species were recovered. Enterobacter hormaechei predominated, followed by Klebsiella pneumoniae and Pantoea species. Whole-genome sequencing revealed closely related strains shared between persons and environmental surfaces, suggesting potential intra-household transmission. We identified >1 horizontal gene transfer event between Enterobacterales genera within a household. On multivariable analysis, households that had children attending daycare, a member with an ADHD diagnosis, and dog ownership were associated with increased odds of household MDR Enterobacterales colonization. Households likely serve as major contributors in acquisition and community spread of MDR Enterobacterales.