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Characterization of small-colony-variant Stenotrophomonas maltophilia isolated from the sputum specimens of five patients with cystic fibrosis.
- Source :
-
Journal of clinical microbiology [J Clin Microbiol] 2007 Feb; Vol. 45 (2), pp. 529-35. Date of Electronic Publication: 2006 Nov 29. - Publication Year :
- 2007
-
Abstract
- Cystic fibrosis (CF) patients are predisposed to chronic respiratory infection by nonfermentative gram-negative bacilli, including Stenotrophomonas maltophilia. S. maltophilia is highly resistant to most antibiotics, with the exception of sulfamethoxazole-trimethoprim (SXT). SXT-resistant S. maltophilia has been reported, but the mechanism of resistance is not well defined. Repeated findings of suspected small-colony-variant (SCV) S. maltophilia isolates from the sputa of five CF patients were confirmed by partial 16S rRNA gene sequencing. The SCV S. maltophilia isolates were the only S. maltophilia isolates in these cultures, and none were clonally related. DNA fingerprint analysis confirmed that once established, the SCV S. maltophilia strains persisted. Nutritional studies of SCV S. maltophilia have suggested auxotrophy in hemin, methionine, and thymidine associated with resistance to multiple antibiotics, including SXT. The phenotypic switch from wild-type to SCV S. maltophilia was reproducible in vitro by exposure to SXT, suggesting that prolonged exposure to antibiotics may select for both the SCV S. maltophilia phenotype and SXT resistance by interference with the dihydrofolate reductase pathway. Recovery of SCV S. maltophilia from the sputum of CF patients has implications for both laboratory testing and patient management.
- Subjects :
- Anti-Bacterial Agents pharmacology
Culture Media
DNA Fingerprinting methods
DNA, Bacterial analysis
Electrophoresis, Gel, Pulsed-Field
Genotype
Humans
Microbial Sensitivity Tests
Phenotype
Polymerase Chain Reaction methods
RNA, Ribosomal, 16S genetics
Stenotrophomonas maltophilia drug effects
Stenotrophomonas maltophilia isolation & purification
Trimethoprim, Sulfamethoxazole Drug Combination pharmacology
Cystic Fibrosis microbiology
Gram-Negative Bacterial Infections microbiology
Sputum microbiology
Stenotrophomonas maltophilia classification
Stenotrophomonas maltophilia growth & development
Subjects
Details
- Language :
- English
- ISSN :
- 0095-1137
- Volume :
- 45
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Journal of clinical microbiology
- Publication Type :
- Academic Journal
- Accession number :
- 17135443
- Full Text :
- https://doi.org/10.1128/JCM.01444-06