A 6-year retrospective study of clinical features, microbiology, and genomics of Shiga toxin-producing Escherichia coli in children who presented to a tertiary referral hospital in Costa Rica

Shiga-toxin-producing Escherichia coli (STEC) is associated with diarrhea and hemolytic uremic syndrome (HUS). STEC infections in Costa Rica are rarely reported in children. We gathered all the records of STEC infections in children documented at the National Children's Hospital, a tertiary referral hospital, from 2015 to 2020. Clinical, microbiological, and genomic information were analyzed and summarized. A total of 3,768 diarrheal episodes were reviewed. Among them, 31 STEC were characterized (29 fecal, 1 urine, and 1 bloodstream infection). The prevalence of diarrheal disease due to STEC was estimated at 0.8% (n = 29/3,768), and HUS development was 6.4% (n = 2/31). The stx1 gene was found in 77% (n = 24/31) of STEC strains. In silico genomic predictions revealed a predominant prevalence of serotype O118/O152:H2, accompanied by a cluster exhibiting allele differences ranging from 33 to 8, using a core-genome multilocus sequence typing (cgMLST) approach. This is the first study using a genomic approach for STEC infections in Costa Rica.