Carbapenem MICs in Escherichia coli and Klebsiella Species Producing Extended-Spectrum β-Lactamases in Critical Care Patients from 2001 to 2009.
Extended-spectrum β-lactamase (ESBL)-producingEnterobacteriaceaestrains are increasing in prevalence worldwide. Carbapenem antibiotics are used as a first line of therapy against ESBL-producingEnterobacteriaceaeWe examined a cohort of critical care patients for gastrointestinal colonization with carbapenem-resistant ESBL-producing strains (CR-ESBL strains). We cultured samples from this cohort of patients for ESBL-producingKlebsiellaspp. andEscherichia coliand then tested the first isolate from each patient for susceptibility to imipenem, doripenem, meropenem, and ertapenem. Multilocus sequence typing was performed on isolates that produced an ESBL and that were carbapenem resistant. Among all patients admitted to an intensive care unit (ICU), 4% were positive for an ESBL-producing isolate and 0.64% were positive for a CR-ESBL strain on surveillance culture. Among the first ESBL-producingE. coliandKlebsiellaisolates from the patients' surveillance cultures, 11.2% were carbapenem resistant. Sequence type 14 (ST14), ST15, ST42, and ST258 were the dominant sequence types detected in this cohort of patients, with ST15 and ST258 steadily increasing in prevalence from 2006 to 2009. Patients colonized by a CR-ESBL strain were significantly more likely to receive antipseudomonal and anti-methicillin-resistantStaphylococcus aureus(anti-MRSA) therapy prior to ICU admission than patients colonized by carbapenem-susceptible ESBL-producing strains. They were also significantly more likely to have received a cephalosporin or a carbapenem antibiotic than patients colonized by carbapenem-susceptible ESBL-producing strains. In conclusion, in a cohort of patients residing in intensive care units within the United States, we found that 10% of the isolates were resistant to at least one carbapenem antibiotic. The continued emergence of carbapenem-resistant ESBL-producing strains is of significant concern, as infections due to these organisms are notoriously difficult to treat.
Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, USA jkjohnson@som.umaryland.edu.|Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA.
J Kristie
JK
Johnson
Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA.
Gwen L
GL
Robinson
Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA.
Lisa L
LL
Pineles
Center for Drug Evaluation and Research, Food and Drug Administration, Sliver Spring, Maryland, USA.
Adebola O
AO
Ajao
Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, USA.
LiCheng
L
Zhao
Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA.
Jennifer S
JS
Albrecht
Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA.
Anthony D
AD
Harris
Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA.
Kerri A
KA
Thom
Department of Pharmacy Practice, Oregon State University/Oregon Health & Science University College of Pharmacy, Portland, Oregon, USA.
Jon P
JP
Furuno
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology; D003422:Critical Care; D000077726:Doripenem; D000077727:Ertapenem; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D015870:Gene Expression; D005838:Genotype; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D007709:Klebsiella / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D007710:Klebsiella Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D008297:Male; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D013845:Thienamycins / Q000494:pharmacology; D014481:United States / Q000453:epidemiology; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism; D047090:beta-Lactams / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D015780:Carbapenems; D013845:Thienamycins; D047090:beta-Lactams; D015378:Imipenem; D000077726:Doripenem; D001618:beta-Lactamases; D000077731:Meropenem; D000077727:Ertapenem
ESBL; MLST; carbapenem resistant