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Comparison of pediatric community-acquired, healthcare-associated, and hospital-acquired infections caused by extended-spectrum cephalosporin-resistant Enterobacteriaceae

Session: Poster Abstract Session: Surveillance of Antimicrobial Resistance
Thursday, October 9, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
Background: We compared the clinical, microbiological and molecular characteristics of community-acquired (CA), healthcare-associated (HCA) and hospital-acquired (HA) extended spectrum cephalosporin-resistant (ESC-R) Enterobacteriaceae infections identified at a free-standing pediatric hospital.

Methods: ESC-R isolates recovered from urine or other normally sterile site during routine clinical care were prospectively collected from September 2009 -September 2013. Targeted organisms were E. coli or K. pneumoniae not susceptible to 3rd generation cephalosporins, cefepime or carbapenems.  Medical record review was performed on infected patients. Infections were categorized as CA (outpatient or < 48 hours after admission from a previously healthy patient without hospitalization in last year), HCA (outpatient or < 48 hours after admission from a patient with chronic conditions or hospitalization in the last year), or HA (> 48 hours after admission with no symptoms of infection on admission).  ESC-R isolates underwent phenotypic and molecular characterization.   


During the study period, 116 ESC-R infections were identified (CA 31%, HCA 56%, HA 13%). HA infections were more likely than CA or HCA infections to involve the blood or peritoneal fluid (40% vs 5%, p =0.001).  Among the ESC-R resistance phenotypes, 79 (68%) were ESBL, 34 (29%) were AmpC, and 3 (3%) were carbapenem resistant. Resistance phenotype did not differ between infection categories. Susceptibilities to non-beta-lactam agents were similar between infection categories, except that CA infections were more likely than HCA or HA infections to be susceptible to trimethoprim-sulfamethoxazole (p=0.007)  E. coli was the predominant species in all infection categories but there was a higher proportion of K. pneumoniae in HCA and HA infections than in CA infections (35% vs 3%, p=0.04). Among ESC-R E. coli, ST131-associated sequence types were more common in CA infections than in HCA and HA infections (40% vs 24%) but this difference was not statistically significant (p=0.09).

Conclusion: CA ESC-R infections accounted for nearly one-third of ESC-R infections identified in our hospital.  CA infections were more likely than HCA or HA infections to involve the urinary tract and be caused by E. coli.

Amanda Adler1, Xuan Qin, PhD2, Scott Weissman, MD3, Matthew Kronman, MD4, Jessica Berry, BS2, Jaipreet Rayar, MS1, Jeffrey Myers, BS1 and Danielle Zerr, MD, MPH, FPIDS5, (1)Seattle Children's Research Institute, Seattle, WA, (2)Department of Laboratory Medicine, University of Washington, Seattle, WA, (3)Seattle Childrens Research Institute, Seattle, WA, (4)Seattle Children's, Seattle, WA, (5)Department of Pediatrics, University of Washington, Seattle, WA


A. Adler, None

X. Qin, None

S. Weissman, None

M. Kronman, None

J. Berry, None

J. Rayar, None

J. Myers, None

D. Zerr, Sage Products: Investigator, Research support
Chimerix, Inc.: Investigator, Research support

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