The Clinical and Molecular Epidemiology of CTX-M-9 Group Producing Enterobacteriaceae infections in children

Abstract

Background:The pandemic of extended-spectrum-beta-lactamase (ESBL)-producing-Enterobacteriaceae (Ent) is strongly linked to the dissemination of CTX-M-type-ESBL-Ent. We sought to define the epidemiology of infections in children due to an emerging resistance type, CTX-M-9-group-producing-Ent (CTX-M-9-grp-Ent). Methods:A multi-centered case-control analysis of Chicago children with CTX-M-9-grp-Ent infections was performed. Cases were defined as children possessing extended-spectrumcephalosporin-resistant (ESC-R) infections. PCR and DNA analysis assessed beta-lactamase (bla) genes, multi-locus sequence types (MLST) and phylogenetic grouping of E. coli. Controls were children with ESC-susceptible (ESC-S)-Ent infections matched 3:1 by age, source, and hospital. The clinical-epidemiologic predictors of CTX-M-9-grp-Ent infection were assessed. Results: Of 356 ESC-R-Ent isolates from children (median age 4.1 years), CTX-M-9-group was the solely detected bla gene in 44(12.4%). The predominant species was E. coli (91%) of virulent phylogroups D(60%) and B2(40%). MLST revealed multiple strain types. On multivariable analysis, CTX-M-9-grp-Ent occurred more often in E. coli (OR 7.0), children of non-black-white-Hispanic race (OR 6.5), and outpatients (OR 4.5) which was a very unexpected finding for infections due to antibiotic-resistant bacteria. Residents of South Chicago were 6.7 times more likely to have CTX-M-9-grp-Ent infections than those in the reference region (West), while residence in Northwestern Chicago was associated with an 81% decreased risk. Other demographic, comorbidity, invasive-device, and antibiotic use differences were not found.Conclusions: CTX-M-9-grp-Ent infection is strikingly associated with patient residence and is occurring in children without traditional in-patient exposure risk factors. This suggests that among children, the community environment may be a key contributor in the spread of these resistant pathogens. of participating institutions for collection, shipping, and cultivation of organisms. We thank the team of curators of the Institut Pasteur MLST and whole-genome MLST databases for curating the data and making them publicly available at

The composition of the microbial community associated with Macrobrachium rosenbergii zoeae varies throughout larval development

“…Most bacterial species within the Enterobacter genus are commonly found in human and animal intestines. Only a few Enterobacter species have been identified as conditional pathogens and have been described to cause extra‐intestinal and invasive infections in humans (Logan et al, ; Logan, Renschler, Sumanth, Weinstein, & Ramanan, ; Lukac, Bonomo, & Logan, ; Mogle, Beccari, Steele, Fazili, & Kufel, ). In aquaculture, the pathogenicity of Enterobacter has been reported relatively infrequently.…”

Whole Genome Sequencing Detects Minimal Clustering Among Escherichia coli Sequence Type 131-H30 Isolates Collected From United States Children’s Hospitals

“…In particular, the relative importance of healthcare vs. community transmission to the propagation of MDR ExPEC lineages remains poorly defined, though recent work indicates community exposures may be more important in pediatric patients. [4] The transmission dynamics of ST131-H30 (hereafter, H30) are challenging to study. Like other ExPEC lineages, H30 is known to asymptomatically colonize the gut for extended periods of time prior to-or potentially without ever-transitioning to extraintestinal infection [5].…”

Spatial clusters of extended-spectrum beta-lactamase-producing Escherichia coli causing community-onset bacteriuria due to repeat infections: cluster analysis from a large urban medical center, San Francisco, 2014-2020

“…In a multi-center study, Logan et al found that children living in South Chicago and those who were diagnosed in outpatient settings were more likely to have infections with CTX-M-9-group-producing Enterobacteriaceae. 25 Arias Ramos et al mapped ESBL-producing Enterobacteriaceae isolates from community infections and colonization events diagnosed at an urban center in Colombia. 26 Using kernel density estimations, they found hotspots of patients with community-acquired infections caused by ESBL-producing Enterobacteriaceae in various communes.…”