Expression of marA is remarkably increased from the early stage of development of fluoroquinolone-resistance in uropathogenic Escherichia coli. Issue 2 (February 2015)

• Record Type: Journal Article
• Authors: Yamasaki, Eiki; Yamada, Chihiro; Jin, Xinghua; Nair, G. Balakrish; Kurazono, Hisao; Yamamoto, Shingo
• Is Part Of: Journal of infection and chemotherapy. Volume 21:Issue 2(2015:Feb.)
• Page Start: 105
• Page End: 109
• Publication Date: 2015-02
• Subjects: Chemotherapy -- Periodicals; Infection -- Periodicals; Communicable diseases -- Chemotherapy -- Periodicals; 615.5805
• DOI: 10.1016/j.jiac.2014.10.007
• Languages: English
• ISSNs: 1341-321X

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Abstract</title> <sec> <title id="sectitle0015">Background</title> <p id="abspara0010">Analyses of efflux pumps overexpression and mutations in quinolone resistance determining region (QRDR) in early stage of development of resistance to fluoroquinolones (FQs) are valuable to discuss countermeasures against them. We induced levofloxacin (LVFX)-resistant strains from susceptible uropathogenic <italic>Escherichia coli</italic> in vitro to analyze the mechanisms of development of FQs-resistance.</p> </sec> <sec> <title id="sectitle0020">Methods</title> <p id="abspara0015">89 strains were exposed to discontinuous elevation of LVFX dose, and mRNA level of efflux pumps and their regulators as well as mutations developed in QRDR of LVFX-resistant strains were analyzed.</p> </sec> <sec> <title id="sectitle0025">Results</title> <p id="abspara0020">In 5 strains, a stepwise increase in MIC to LVFX (up to >128 μg/ml)was observed. Compared to the parent strains, additional mutations in QRDR were observed in the strains developing high MIC. Remarkable increase of <italic>marA</italic> expression was observed even in the early stage of LVFX-resistance development, and it lasted until high-level resistance was developed. On the other hand, moderate increase in <italic>acrB</italic> expression but only low increase in <italic>yhiU</italic>, <italic>yhiV</italic>, <italic>mdfA</italic>, <italic>tolC</italic> and <italic>sdiA</italic> were observed.</p> </sec> <sec> <title id="sectitle0030">Conclusions</title> <p id="abspara0025">These results suggested that <italic>marA</italic> expression is a sensitive marker for early detection of development of LVFX-resistance.</p> </sec> </abstract>