Characterization of putative multidrug resistance transporters of the major facilitator-superfamily expressed in Salmonella Typhi.
Multidrug resistance mediated by efflux pumps is a well-known phenomenon in infectious bacteria. Although much work has been carried out to characterize multidrug efflux pumps in Gram-negative and Gram-positive bacteria, such information is still lacking for many deadly pathogens. The aim of this study was to gain insight into the substrate specificity of previously uncharacterized transporters of Salmonella Typhi to identify their role in the development of multidrug resistance. S. Typhi genes encoding putative members of the major facilitator superfamily were cloned and expressed in the drug-hypersensitive Escherichia coli strain KAM42, and tested for transport of 25 antibacterial compounds, including representative antibiotics of various classes, antiseptics, dyes and detergents. Of the 15 tested putative transporters, STY0901, STY2458 and STY4874 exhibited a drug-resistance phenotype. Among these, STY4874 conferred resistance to at least ten of the tested antimicrobials: ciprofloxacin, norfloxacin, levofloxacin, kanamycin, streptomycin, gentamycin, nalidixic acid, chloramphenicol, ethidium bromide, and acriflavine, including fluoroquinolone antibiotics, which were drugs of choice to treat S. Typhi infections. Cell-based functional studies using ethidium bromide and acriflavine showed that STY4874 functions as a H(+)-dependent exporter. These results suggest that STY4874 may be an important drug target, which can now be tested by studying the susceptibility of a STY4874-deficient S. Typhi strain to antimicrobials.
Drug Discovery and Structural Biology Group, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan; Pakistan Institute of Engineering and Applied Sciences, Islamabad, Pakistan; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
Aqsa
A
Shaheen
Drug Discovery and Structural Biology Group, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan.
Fouzia
F
Ismat
Drug Discovery and Structural Biology Group, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan; Pakistan Institute of Engineering and Applied Sciences, Islamabad, Pakistan.
Mazhar
M
Iqbal
The University of Faisalabad, Faisalabad, Pakistan.
Abdul
A
Haque
Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA.
Rita
R
De Zorzi
Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Osman
O
Mirza
Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA.
Thomas
T
Walz
Drug Discovery and Structural Biology Group, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan; Pakistan Institute of Engineering and Applied Sciences, Islamabad, Pakistan; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: moazur@yahoo.com.
Moazur
M
Rahman
D000167:Acriflavine / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000378:metabolism / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001548:Benzalkonium Compounds / Q000378:metabolism / Q000494:pharmacology; D003902:Detergents / Q000378:metabolism / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D004926:Escherichia coli; D004996:Ethidium / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism / Q000494:pharmacology; D015870:Gene Expression; D005822:Genetic Vectors; D008826:Microbial Sensitivity Tests; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism*; D012485:Salmonella typhi / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
D000167:Acriflavine; D000900:Anti-Bacterial Agents; D000891:Anti-Infective Agents, Local; D001426:Bacterial Proteins; D001548:Benzalkonium Compounds; D003902:Detergents; D004996:Ethidium; D005456:Fluorescent Dyes; D009004:Monosaccharide Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C000605218:multidrug resistance transporter STY0901, Salmonella typhi; C000605219:multidrug resistance transporter STY2458, Salmonella typhi; C000605217:multidrug resistance transporter STY4874, Salmonella typhi
Efflux pump; MDR pump; MFS; Multidrug resistance; Salmonella Typhi