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Induction of L1 and L2 beta-lactamases of Stenotrophomonas maltophilia.

ABSTRACT: Isogenic L1 and L2 gene knockout mutants of Stenotrophomonas maltophilia KJ (KJDeltaL1 and KJDeltaL2, respectively) were constructed by xylE gene replacement. Induction kinetics of the L1 and L2 genes were evaluated by testing catechol 2,3-dioxygenase activity in the mutants. The results suggested that the induction of the L1 and L2 genes was differentially regulated.

SUBMITTER: Hu RM

PROVIDER: S-EPMC2258547 | biostudies-literature | 2008 Mar

REPOSITORIES: biostudies-literature

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Induction of L1 and L2 beta-lactamases of Stenotrophomonas maltophilia.

Hu Rouh-Mei RM Huang Kuang-Jay KJ Wu Lii-Tzu LT Hsiao Ying-Ju YJ Yang Tsuey-Ching TC

Antimicrobial agents and chemotherapy 20071217 3

Isogenic L1 and L2 gene knockout mutants of Stenotrophomonas maltophilia KJ (KJDeltaL1 and KJDeltaL2, respectively) were constructed by xylE gene replacement. Induction kinetics of the L1 and L2 genes were evaluated by testing catechol 2,3-dioxygenase activity in the mutants. The results suggested that the induction of the L1 and L2 genes was differentially regulated. ...[more]

PMID: 18086856

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AmpDI is involved in expression of the chromosomal L1 and L2 beta-lactamases of Stenotrophomonas maltophilia.

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Interplay among membrane-bound lytic transglycosylase D1, the CreBC two-component regulatory system, the AmpNG-AmpDI-NagZ-AmpR regulatory circuit, and L1/L2 β-lactamase expression in Stenotrophomonas maltophilia.

Project description:Lytic transglycosylases (LTs) are an important class of enzymes involved in peptidoglycan (PG) cleavage, with the concomitant formation of an intramolecular 1,6-anhydromuramoyl reaction product. There are six annotated LT genes in the Stenotrophomonas maltophilia genome, including genes for five membrane-bound LTs (mltA, mltB1, mltB2, mltD1, and mltD2) and a gene for soluble LT (slt). Six LTs of S. maltophilia KJ were systematically mutated, yielding the ΔmltA, ΔmltB1, ΔmltB2, ΔmltD1, ΔmltD2, and Δslt mutants. Inactivation of mltD1 conferred a phenotype of elevated uninduced β-lactamase activity. The underlying mechanism responsible for this phenotype was elucidated by the construction of several mutants and determination of β-lactamase activity. The expression of the genes assayed was assessed by quantitative reverse transcriptase PCR and a promoter transcription fusion assay. The results demonstrate that ΔmltD1 mutant-mediated L1/L2 β-lactamase expression involved the creBC two-component regulatory system (TCS) and the ampNG-ampDI-nagZ-ampR regulatory circuit. The inactivation of mltD1 resulted in mltB1 and mltD2 upexpression in a creBC- and ampNG-dependent manner. The overexpressed MltB1 and MltD2 activity contributed to the expression of the L1/L2 β-lactamase genes via the ampNG-ampDI-nagZ-ampR regulatory circuit. These findings reveal, for the first time, a linkage between LTs, the CreBC TCS, the ampNG-ampDI-nagZ-ampR regulatory circuit, and L1/L2 β-lactamase expression in S. maltophilia.

| S-EPMC4604389 | biostudies-literature

Genome sequence of Stenotrophomonas maltophilia S028, an isolate harboring the AmpR-L2 resistance module.

Project description:Multidrug-resistant Stenotrophomonas maltophilia has emerged as an important cause of nosocomial infections, which is attributable mainly to the production of diverse β-lactamases by S. maltophilia. The L2 β-lactamase mediated by the AmpR-L2 module is the most represented lactamase. Here, we announce the genome sequence of S028, an isolate harboring the AmpR-L2 module.

| S-EPMC3497473 | biostudies-literature

Stenotrophomonas maltophilia FLR19 response to pH

Project description:We sought to determine how a cystic fibrosis isolate of Stenotrophomonas maltophilia responds to relevant pH gradients (pH 5, 7, and 9) by growing the bacterium in phosphate buffered media and conducting RNAseq experiments. Our data suggests acidic conditions are stressful for strain FLR19, as it responded by increasing expression of stress-response and antibiotic-resistance genes.

2018-10-17 | GSE121347 | GEO

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