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BioMed Research International
Volume 2015, Article ID 580240, 10 pages
http://dx.doi.org/10.1155/2015/580240
Research Article

Identification and Characterization of a Serious Multidrug Resistant Stenotrophomonas maltophilia Strain in China

1Department of Critical Care Medicine, Affiliated Hospital of Academy of Military Medical Science, Beijing 100071, China
2The Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing 100071, China
3Department of Respiratory Diseases, The First Affiliated Hospital of Liaoning Medical University, Jinzhou, Liaoning 121001, China
4Jinan Fourth People’s Hospital, Jinan 250031, Shandong, China
5Beijing Institute of Biotechnology, Beijing 100071, China

Received 24 August 2014; Accepted 1 December 2014

Academic Editor: Thomas Lufkin

Copyright © 2015 Yan Zhao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

An S. maltophilia strain named WJ66 was isolated from a patient; WJ66 showed resistance to more antibiotics than the other S. maltophilia strains. This bacteraemia is resistant to sulphonamides, or fluoroquinolones, while the representative strain of S. maltophilia, K279a, is sensitive to both. To explore drug resistance determinants of this strain, the draft genome sequence of WJ66 was determined and compared to other S. maltophilia sequences. Genome sequencing and genome-wide evolutionary analysis revealed that WJ66 was highly homologous with the strain K279a, but strain WJ66 contained additional antibiotic resistance genes. Further analysis confirmed that strain WJ66 contained an amino acid substitution (Q83L) in fluoroquinolone target GyrA and carried a class 1 integron, with an aadA2 gene in the resistance gene cassette. Homology analysis from the pathogen-host interaction database showed that strain WJ66 lacks raxST and raxA, which is consistent with K279a. Comparative genomic analyses revealed that subtle nucleotide differences contribute to various significant phenotypes in close genetic relationship strains.