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Eighteen years of experience with Acinetobacter baumannii in a tertiary care hospital. Crit Care Med 2013 Dec;41(12):2733-42

Date

08/29/2013

Pubmed ID

23982021

DOI

10.1097/CCM.0b013e318298a541

Abstract

OBJECTIVE: To characterize the descriptive and molecular epidemiology of Acinetobacter baumannii in our hospital.

DESIGN: Longitudinal analysis of electronic microbiology laboratory records and isolates.

SETTING: A 1,500 bed public teaching hospital in the Miami area.

PATIENTS: Consecutive patients with A. baumannii from January 1994 to December 2011.

INTERVENTIONS: None

MEASUREMENTS AND MAIN RESULTS: : Data on all A. baumannii isolates were clustered at the patient level, and the first isolate per single patient was determined. Yearly trends were analyzed based on carbapenem susceptibilities and originating units for all first isolates and first blood isolates per unique patient. Additionally, carbapenem nonsusceptible isolates frozen in the microbiology laboratory since 1998 were retrieved and evaluated using polymerase chain reaction and randomly amplified polymorphic DNA techniques. A total of 9,334 A. baumannii isolates were detected, of which 4,484 isolates (48%) were identified as first positive isolates per unique patient. Most of the burden of disease was located in the ICUs (odds ratio, 2.64 [95% CI, 2.17-3.22]; p < 0.0001) and in the adult wards (odds ratio, 3.867 [95% CI, 2.71-5.52]; p < 0.0001). Respiratory specimens constituted the most frequent source (49%; odds ratio, 1.619 [95% CI, 1.391-1.884]; p < 0.0001). Of the 4,484 first isolates, 846 isolates (18.9%) were carbapenem nonsusceptible and 3,638 isolates (81.1%) were carbapenem susceptible. Over the years, the number of carbapenem nonsusceptible isolates increased, whereas the number of carbapenem susceptible decreased (p < 0.0001). The trauma ICU had the highest burden of carbapenem nonsusceptible first isolates (205 of 846; 24.2%). Seven clones were discovered among 144 carbapenem nonsusceptible isolates; one of these clones was found from 1999 to 2005. OXA-23 and OXA-40 were identified in 96 and 13 isolates, respectively. One isolate harbored a novel CTX-M-115 enzyme.

CONCLUSIONS: This constitutes the largest experience with A. baumannii reported to date from a single center. Half of all isolates were respiratory specimens and were from adult ICUs, especially trauma. Even though this was a polyclonal process, a single clone was identified in the hospital through a 6-year span.

Author List

Munoz-Price LS, Arheart K, Nordmann P, Boulanger AE, Cleary T, Alvarez R, Pizano L, Namias N, Kett DH, Poirel L

Author

L Silvia Munoz-Price MD, PhD Professor in the Medicine department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Acinetobacter Infections
Acinetobacter baumannii
Blood
Carbapenems
DNA, Bacterial
Drug Resistance, Bacterial
Florida
Humans
Intensive Care Units
Longitudinal Studies
Microbial Sensitivity Tests
RNA, Ribosomal, 16S
Respiratory System
Retrospective Studies
Tertiary Care Centers
Wounds and Injuries
beta-Lactamases
jenkins-FCD Prod-486 e3098984f26de787f5ecab75090d0a28e7f4f7c0