Identification and Characterization of a Serious Multidrug ResistantStenotrophomonas maltophiliaStrain in China
AnS. maltophiliastrain named WJ66 was isolated from a patient; WJ66 showed resistance to more antibiotics than the otherS. maltophiliastrains. This bacteraemia is resistant to sulphonamides, or fluoroquinolones, while the representative strain ofS. 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 otherS. maltophiliasequences. 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 anaadA2gene 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.