Burkholderia pseudomallei is the aetiological agent of melioidosis. Therapy for this disease is lengthy and limited to only a few antibiotics because of this... more
Burkholderia pseudomallei is the aetiological agent of melioidosis. Therapy for this disease is lengthy and limited to only a few antibiotics because of this bacterium's intrinsic antibiotic resistance to many clinically useful antibiotics. These properties of B. pseudomallei may partially be due to expression of efflux pumps of the resistance-nodulation-cell-division (RND) family. The patterns and magnitude of RND efflux pump expression in commonly used strains and clinical isolates of B. pseudomallei from the Royal Darwin Hospital, Darwin, Australia, were assessed in cells grown to late exponential phase using quantitative real-time PCR (qRT-PCR). Expression of the three previously identified RND efflux pumps AmrAB-OprA, BpeAB-OprB and BpeEF-OprC, as well as four other yet uncharacterized pumps, was found to be widespread in the clinical isolates. In 45 of 50 isolates (90%), mRNA was detected for at least one of the seven RND pumps. Of these 45 isolates, 41 (82%) expressed multiple pumps with nine strains expressing all seven pumps tested. While these studies revealed no striking correlation between RND efflux pump expression and clinically significant antibiotic resistance, the data support the notion that RND pumps probably play important roles in this bacterium's physiology, defence against toxic compounds, and perhaps virulence.
Research Interests:
Research Interests: Genetics, Multidisciplinary, Escherichia coli, Applied, United States, and 12 moreApplied Environmental Microbiology, Bacteria, Plasmids, Molecular cloning, Efflux Pumps, Bleomycin, Host Range, Base Sequence, Natural Transformation, Temperature Sensitive Polymer, DNA fragmentation, and Molecular Sequence Data
Research Interests:
Research Interests: Genetics, Microbiology, Medical Microbiology, Regulation, Gene expression, and 19 moreAntibiotic Resistance, Cell Division, Identification, Multidrug Resistance, Method, Bacteria, Membrane transport, Gene, Pseudomonas aeruginosa, Gen, Genetically Modified, Anti-Bacterial Agents, Strain, Antimicrobial agents, Microbial Sensitivity Tests, Genetic Recombination, Efflux Pumps, Pseudomonas Aeruginosa, and Chloramphenicol
Acinetobacter baumannii is an emerging pathogen that causes serious infections with high mortality rates in immunocompromised individuals. Genetic manipulations in this medically-relevant pathogen are limited by the paucity of molecular... more
Acinetobacter baumannii is an emerging pathogen that causes serious infections with high mortality rates in immunocompromised individuals. Genetic manipulations in this medically-relevant pathogen are limited by the paucity of molecular tools. In this study, we show the application of the mini-Tn7-based single copy insertion system in A. baumannii. Mini-Tn7 elements are known to integrate at a naturally evolved, therefore presumably neutral location (intergenic region) downstream of the glmS gene (glucosamine-fructose-6-phosphate aminotransferase) in Gram-negative bacteria. We identified the site of insertion of mini-Tn7 in A. baumannii and demonstrated application of this useful cloning tool by inserting the gfp gene into the chromosome. Our work shows that mini-Tn7 elements are useful tools for genetic studies in this important pathogen.