Antimicrobial resistance is a global public health threat and a danger that continues to escalate. These menacing bacteria are having an impact on all populations; however, until recently, the increasing trend in drug-resistant infections in infants and children has gone relatively unrecognized. This article highlights the current clinical and molecular data regarding infection with antibiotic-resistant bacteria in children, with an emphasis on transmissible resistance and spread via horizontal gene transfer.

Background: Fluoroquinolones (FQs) are uncommonly prescribed in children, yet pediatric multidrug-resistant (MDR)-Enterobacteriaceae (Ent) infections often reveal FQ resistance (FQR). We sought to define the molecular epidemiology of FQR and MDR-Ent in children. Methods:A case-control analysis of children with MDR-Ent infections at 3 Chicago hospitals was performed. Cases were children with third-generation-cephalosporin-resistant (3GCR) and/or carbapenem-resistant (CR)-Ent infections. PCR and DNA analysis assessed bla and plasmidmediated FQR (PMFQR) genes. Controls were children with 3GC, FQ and carbapenem

Introduction 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 retrospective matched case-control analysis of children with CTX-M-9-grp-Ent infections who received medical care at three Chicago area hospitals was performed. Cases were defined as children possessing extended-spectrum cephalosporin-resistant (ESC-R) infections due to bla CTX-M-9 . 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 one case to three controls 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), the 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 than other Ent genera (OR 7.4, 95% CI 2.4, 27.2), children of non-Black-White-Hispanic race (OR 7.4, 95% CI 2.4, 28.2), and outpatients (OR 4.5, 95% CI 1.7, 12.3), which was a very unexpected finding for infections due to antibiotic-resistant bacteria. Residents of South Chicago had a 6.7 times higher odds of having CTX-M-9-grp-Ent infections than those in the reference region (West), while residence in Northwestern Chicago was associated with an 81% decreased odds of infection. Other demographic, comorbidity, invasive-device, and antibiotic use differences were not found. Conclusion CTX-M-9-grp-Ent infection may be 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.

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

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 bla TEM and bla SHV (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 bla TEM or bla SHV. 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 bla TEM-ESBL (26%) or bla SHV-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.