%0 Journal Article
%T A multicopy suppressor screening approach as a means to identify antibiotic resistance determinant candidates in Yersinia pestis
%A Karen L Stirrett
%A Julian A Ferreras
%A Sebastian M Rossi
%A Richard L Moy
%A Fabio V Fonseca
%A Luis EN Quadri
%J BMC Microbiology
%D 2008
%I BioMed Central
%R 10.1186/1471-2180-8-122
%X We constructed a multicopy plasmid-based, Y. pestis genome-wide expression library of nearly 16,000 clones in E. coli and screened the library for suppressors of the antimicrobial activity of ofloxacin, a fluoroquinolone antibiotic. The screen permitted the identification of a transcriptional regulator-encoding gene (robAYp) that increased the MIC99 of ofloxacin by 23-fold when overexpressed from a multicopy plasmid in Y. pestis. Additionally, we found that robAYp overexpression in Y. pestis conferred low-level resistance to many other antibiotics and increased organic solvent tolerance. Overexpression of robAYp also upregulated the expression of several efflux pumps in Y. pestis.Our study provides proof of principle for the use of multicopy suppressor screening based on the tractable and easy-to-manipulate E. coli host as a means to identify antibiotic resistance determinant candidates of Y. pestis.Yersinia pestis (Yp) is one of the most virulent known bacteria [1] and a potential agent of bioterrorism and biowarfare [2,3] included in the Category A of biological agents for public health preparedness against bioterrorism [4]. Yp is the etiologic agent of plague, a disease responsible for millions of human deaths during the history of civilization [5,6]. Cases are reported every year in many parts of the world [7] and the increasing number of worldwide cases has placed plague in the category of re-emerging diseases [8].Patients with plague need prompt antibiotic treatment or else death may be unavoidable. The aminoglycosides streptomycin (STR) and gentamicin (GEN) are the preferred antibiotics for treatment, but a number of other drugs are also effective [9,10]. Tetracyclines [such as doxycycline (DOX)], chloramphenicol (CHL), or selected sulfonamides are the recommended antibiotics for prophylactic therapy in the event of exposure or high risk of exposure to Yp [2,9,10]. Fluoroquinolones have also been suggested for treatment and prophylaxis and are noted as a chem
%U http://www.biomedcentral.com/1471-2180/8/122