Impact of mutations in DNA gyrase genes on quinolone resistance in Campylobacter jejuni. Issue 10 (9th February 2016)

• Record Type: Journal Article
• Authors: Changkwanyeun, Ruchirada; Yamaguchi, Tomoyuki; Kongsoi, Siriporn; Changkaew, Kanjana; Yokoyama, Kazumasa; Kim, Hyun; Suthienkul, Orasa; Usui, Masaru; Tamura, Yutaka; Nakajima, Chie; Suzuki, Yasuhiko
• Is Part Of: Drug testing and analysis. Volume 8:Issue 10(2016:Oct.)
• Page Start: 1071
• Page End: 1076
• Publication Date: 2016-02-09
• Subjects: Campylobacter jejuni -- quinolone resistance -- DNA gyrase -- mutation; Drugs -- Analysis -- Periodicals; Drug testing -- Periodicals; Chemistry, Forensic -- Periodicals; 615.1901
• DOI: 10.1002/dta.1937
• Languages: English
• ISSNs: 1942-7603

Abstract

Abstract : Amino acid substitutions providing quinolone resistance to Campyloabcter jejuni have been found in the quinolone resistance‐determining region of protein DNA gyrase subunit A (GyrA), with the highest frequency at position 86 followed by position 90. In this study, wild‐type and mutant recombinant DNA gyrase subunits were expressed in Escherichia coli and purified using Ni‐NTA agarose column chromatography . Soluble 97 kDa GyrA and 87 kDa DNA gyrase subunit B were shown to reconstitute ATP‐dependent DNA supercoiling activity. A quinolone‐inhibited supercoiling assay demonstrated the roles of Thr86Ile, Thr86Ala, Thr86Lys, Asp90Asn, and Asp90Tyr amino acid substitutions in reducing sensitivity to quinolones. The marked effect of Thr86Ile on all examined quinolones suggested the advantage of this substitution in concordance with recurring isolation of quinolone‐resistant C. jejuni . An analysis of the structure‐activity relationship showed the importance of the substituent at position 8 in quinolones to overcome the effect of Thr86Ile. Sitafloxacin (SIT), which has a fluorinate cyclopropyl ring at R‐1 and a chloride substituent at R‐8, a characteristic not found in other quinolones, showed the highest inhibitory activity against all mutant C. jejuni gyrases including ciprofloxacin‐resistant mutants. The results suggest SIT as a promising drug for the treatment of campylobacteriosis caused by CIP‐resistant C. jejuni . Copyright © 2016 John Wiley & Sons, Ltd. Abstract : CIP‐inhibited DNA supercoiling assay revealed the strong effect of amino acid substitution from Thr to Ile at the amino acid 86 in GyrA on CIP resistance. (A) WT GyrB‐WT GyrA, (B) GyrA‐Thr86Ile, (C) GyrA‐Thr86Ala, (D) GyrA‐Thr86Lys, (E) GyrA‐Asp90Asn, and (F) GyrA‐Asp90Tyr. R: relaxed pBR322 DNA, SC: supercoiled pBR322 DNA.