A Multicentered Study of the Clinical and Molecular Epidemiology of TEM- and SHV-type Extended-Spectrum Beta-Lactamase Producing Enterobacterales Infections in Children.

Background: Extended-spectrum β-lactamase (ESBL)-producing Enterobacterales-(Ent) infections are increasing in pediatrics. Before CTX-M ESBL emerged, the most common infection-associated ESBL genes were TEM and SHV-type ESBLs. We sought to define the current epidemiology of Ent infections in children due to blaTEM and blaSHV (TEM-SHV-Ent).
Methods: A retrospective case-control analysis of children with TEM-SHV-Ent infections at 3 Chicago-area hospitals was performed. Cases had extended-spectrum-cephalosporin (ESC)-resistant infections due to blaTEM or blaSHV. DNA analysis assessed β-lactamase (bla) genes, multilocus sequence types, and E. coli phylogenetic grouping. Controls had ESC-susceptible Ent infections, matched 3:1 to cases by age, source, and hospital. Clinical-epidemiologic infection predictors were assessed.
Results: Of 356 ESC-R-Ent isolates from children (median 4.3 years), 38 (10.7%) were positive solely for blaTEM-ESBL (26%) or blaSHV-ESBL genes (74%). Predominant organisms were Klebsiella (34.2%) and E. coli (31.6%); 67% of E. coli were phylogroup B2. Multilocus sequence types revealed multiple strains, 58% resistant to ≥3 antibiotic classes. On multivariable analysis, children with TEM-SHV-Ent infections more often had recent inpatient care (OR, 8.2), yet were diagnosed mostly as outpatients (OR, 25.6) and less in Neonatal Intensive Care Units (OR, 0.036) than controls. TEM-SHV-Ent patients had more gastrointestinal (OR, 23.7) and renal comorbidities (OR, 4.2). Differences in demographics, antibiotic exposure, and foreign bodies were not found.
Conclusion: TEM-SHV-Ent are commonly linked to inpatient exposures in children with chronic conditions but most often present in outpatient settings. Clinicians should be aware of the potential increased risk for TEM-SHV-Ent infections in outpatients with gastrointestinal and renal comorbidities and histories of prolonged hospital stays.