Hao-Yuan Lee1, Chih-Wei Huang2, Chyi-Liang Chen2, Yi-Hsin Wang2, Chee-Jen Chang3, Cheng-Hsun Chiu4. 1. Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Taoyuan, Taiwan; Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan. 2. Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan. 3. Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Taoyuan, Taiwan. 4. Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Taoyuan, Taiwan; Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan. Electronic address: chchiu@adm.cgmh.org.tw.
Abstract
BACKGROUND: Acinetobacter baumannii is one of the most important noscomial pathogens worldwide. The study aimed to use multilocus sequence typing (MLST) for epidemiological surveillance of A. baumannii isolates in Taiwan and analyze the clinical presentations and patients' outcomes. METHODS: MLST according to both Bartual's PubMLST and Pasteur's MLST schemes was applied to characterize bloodstream imipenem-resistant A. baumannii (IRAB) infection in intensive care units in a medical center. A total of 39 clinical IRAB bloodstream isolates in 2010 were enrolled. We also collected 13 imipenem-susceptible A. baumannii bloodstream isolates and 30 clinical sputum isolates (24 IRAB and 6 imipenem-susceptible A. baumannii) for comparison. Clinical presentations and outcome of the patients were analyzed. RESULTS: We found that infection by ST455B/ST2P and inappropriate initial therapy were statistically significant risk factors for mortality. More than one third of the IRAB isolates belonged to ST455B/ST2P. Most ST455B/ST2P (80%) carried ISAba1-blaOXA-23, including 10 (66.7%) with Tn2006 (ISAba1-blaOXA-23-ISAba1) in an AbaR4-type resistance island. ST455B/ST2P appears to evolve from ST208B/ST2P of clonal complex (CC) 92B/CC2P. In this hospital-based study, A. baumannii ST455 accounted for 38.5% of IRAB bacteremia, with a high mortality of 86.7%. Approximately 85% of ST455B/ST2P bacteremia had a primary source of ventilation-associated pneumonia. CONCLUSION: We report the emergence in Taiwan of IRAB ST455B/ST2P, which is the current predominant clone of IRAB in our hospital and has been causing bacteremia with high mortality in critical patients.
BACKGROUND:Acinetobacter baumannii is one of the most important noscomial pathogens worldwide. The study aimed to use multilocus sequence typing (MLST) for epidemiological surveillance of A. baumannii isolates in Taiwan and analyze the clinical presentations and patients' outcomes. METHODS: MLST according to both Bartual's PubMLST and Pasteur's MLST schemes was applied to characterize bloodstream imipenem-resistant A. baumannii (IRAB) infection in intensive care units in a medical center. A total of 39 clinical IRAB bloodstream isolates in 2010 were enrolled. We also collected 13 imipenem-susceptible A. baumannii bloodstream isolates and 30 clinical sputum isolates (24 IRAB and 6 imipenem-susceptible A. baumannii) for comparison. Clinical presentations and outcome of the patients were analyzed. RESULTS: We found that infection by ST455B/ST2P and inappropriate initial therapy were statistically significant risk factors for mortality. More than one third of the IRAB isolates belonged to ST455B/ST2P. Most ST455B/ST2P (80%) carried ISAba1-blaOXA-23, including 10 (66.7%) with Tn2006 (ISAba1-blaOXA-23-ISAba1) in an AbaR4-type resistance island. ST455B/ST2P appears to evolve from ST208B/ST2P of clonal complex (CC) 92B/CC2P. In this hospital-based study, A. baumannii ST455 accounted for 38.5% of IRAB bacteremia, with a high mortality of 86.7%. Approximately 85% of ST455B/ST2P bacteremia had a primary source of ventilation-associated pneumonia. CONCLUSION: We report the emergence in Taiwan of IRAB ST455B/ST2P, which is the current predominant clone of IRAB in our hospital and has been causing bacteremia with high mortality in critical patients.
Authors: Michelle Lowe; Marthie M Ehlers; Farzana Ismail; Gisele Peirano; Piet J Becker; Johann D D Pitout; Marleen M Kock Journal: Front Microbiol Date: 2018-06-12 Impact factor: 5.640