Search tips
Search criteria

Results 1-3 (3)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
Document Types
1.  Coordinate Hyperproduction of SmeZ and SmeJK Efflux Pumps Extends Drug Resistance in Stenotrophomonas maltophilia 
A Stenotrophomonas maltophilia mutant that coordinately hyper-expresses three resistance nodulation division-type efflux pump genes, smeZ, smeJ, and smeK, has been identified. SmeZ is responsible for elevating aminoglycoside MICs; SmeJ and SmeK are jointly responsible for elevating tetracycline, minocycline, and ciprofloxacin MICs and conferring levofloxacin resistance. One clinical isolate with this same phenotype was identified from a sample of six, and the isolate also coordinately hyper-expresses smeZ and smeJK, confirming the clinical relevance of our findings.
PMCID: PMC3535947  PMID: 23147729
2.  The complete genome, comparative and functional analysis of Stenotrophomonas maltophilia reveals an organism heavily shielded by drug resistance determinants 
Genome Biology  2008;9(4):R74.
The complete Stenotrophomonas maltophilia genome sequence suggests that it can act as a reservoir of antibiotic resistance determinants.
Stenotrophomonas maltophilia is a nosocomial opportunistic pathogen of the Xanthomonadaceae. The organism has been isolated from both clinical and soil environments in addition to the sputum of cystic fibrosis patients and the immunocompromised. Whilst relatively distant phylogenetically, the closest sequenced relatives of S. maltophilia are the plant pathogenic xanthomonads.
The genome of the bacteremia-associated isolate S. maltophilia K279a is 4,851,126 bp and of high G+C content. The sequence reveals an organism with a remarkable capacity for drug and heavy metal resistance. In addition to a number of genes conferring resistance to antimicrobial drugs of different classes via alternative mechanisms, nine resistance-nodulation-division (RND)-type putative antimicrobial efflux systems are present. Functional genomic analysis confirms a role in drug resistance for several of the novel RND efflux pumps. S. maltophilia possesses potentially mobile regions of DNA and encodes a number of pili and fimbriae likely to be involved in adhesion and biofilm formation that may also contribute to increased antimicrobial drug resistance.
The panoply of antimicrobial drug resistance genes and mobile genetic elements found suggests that the organism can act as a reservoir of antimicrobial drug resistance determinants in a clinical environment, which is an issue of considerable concern.
PMCID: PMC2643945  PMID: 18419807
3.  nalD Encodes a Second Repressor of the mexAB-oprM Multidrug Efflux Operon of Pseudomonas aeruginosa▿  
Journal of Bacteriology  2006;188(24):8649-8654.
The Pseudomonas aeruginosa nalD gene encodes a TetR family repressor with homology to the SmeT and TtgR repressors of the smeDEF and ttgABC multidrug efflux systems of Stenotrophomonas maltophilia and Pseudomonas putida, respectively. A sequence upstream of mexAB-oprM and overlapping a second promoter for this efflux system was very similar to the SmeT and TtgR operator sequences, and NalD binding to this region was, in fact, demonstrated. Moreover, increased expression from this promoter was seen in a nalD mutant, consistent with NalD directly controlling mexAB-oprM expression from a second promoter.
PMCID: PMC1698243  PMID: 17028276

Results 1-3 (3)