Methods: In this prospective surveillance study led at 4 US free-standing children’s hospitals, ESC-R E. coli isolated from normally sterile sites of patients <21 years of age between October 1, 2009 and September 30, 2013 were included. The total number of E. coli isolates recovered from sterile sites during the study period at each hospital was used to estimate ESC-R E. coli prevalence. For each ESC-R isolate, 3 ESC-S E. coli isolates were also collected; clinical data were obtained via medical record review. All isolates were subjected to sequencing of fumC and fimH (CH typing). The distribution of CH types was examined by onset of infection, which was categorized as community-acquired (CA) healthcare-associated (HCA) or hospital-acquired (HA). Simpson’s diversity index was used to assess genotypic diversity.
Results: The overall prevalence of ESC-R extraintestinal E. coliduring the study period was 1.2%. A total of 268 ESC-R isolates and 797 ESC-S isolates were further characterized; 256 unique CH types were identified across ESC-R and ESC-S isolates. The most common CH type was the ST131-associated 40-30 clone (5% of ESC-S; 31% of ESC-R isolates); other common CH types included 35-27 (11% of ESC-S; 3% of ESC-R), 38-41 (10% of ESC-S; 1% of ESC-R), 24-10 (5% of ESC-S; 0% of ESC-R), and 14-27 (4% of ESC-S; 0% of ESC-R). CH type 40-30 accounted for nearly equal proportions of CA, HCA, and HA ESC-R infections (30% vs 31% vs 29%, respectively); however, among ESC-S infections, CH type 40-30 accounted for only 2% of CA infections, 10% HCA infections, and 6% HA infections. Clonal diversity was lower among ESC-R isolates (Simpson’s D 90.1%; 95% CI 86.8-93.3%) than ESC-S isolates (Simpson’s D 96.8%; 95% CI 96.2-97.3%).
Conclusion: Among pediatric E. coli, ESC-R isolates are less clonally diverse than ESC-S isolates due to the predominance of the ST131-associated CH type 40-30. This emergent, multidrug-resistant clone was responsible for approximately 30% of ESC-R infections regardless of community versus healthcare or hospital onset.
S. Weissman, None
X. Qin, None
M. Kronman, None
J. Berry, None
J. Rayar, None
J. Myers, None
C. A. D. Burnham, None
A. Elward, None
J. Newland, Pfizer/Joint Commission: Grant Investigator , Research grant
RPSdiagnostics: Consultant , Consulting fee
R. Selvarangan, None
K. V. Sullivan, None
T. Zaoutis, Merck: Investigator , Consulting fee and Research grant
Cubist: Investigator , Research support
D. Zerr, None
See more of: Poster Abstract Session