Specific patterns of gyr A mutations determine the resistance difference to ciprofloxacin and levofloxacin in Klebsiella pneumoniae andEscherichia coli

BMC Infectious Diseases

Research Article

Xiaobei Chen¹  Song Zhao²  Ying Zhang³  Yang Chen³  Hui Xu³  Yingmei Fu³  Wenli Zhang³  Fanfei Meng³  Fengmin Zhang⁴  Hong Wang⁵ 

[1] Bio-pharmaceutical Key Laboratory of Ministry of Education, Harbin Medical University, Harbin, China;Department of General Surgery, Minimally Invasive Surgery, First Affiliated Hospital, Harbin Medical University, 150010, Harbin, China;Department of Microbiology, Heilongjiang Province Key Laboratory for Immunity and infection, Pathogenic biology, Bio-pharmaceutical Key Laboratory of Ministry of Education, Harbin Medical University, 157 Baojian Road, 150086, Harbin, China;Department of Microbiology, Heilongjiang Province Key Laboratory for Immunity and infection, Pathogenic biology, Bio-pharmaceutical Key Laboratory of Ministry of Education, Harbin Medical University, 157 Baojian Road, 150086, Harbin, China;Bio-pharmaceutical Key Laboratory of Ministry of Education, Harbin Medical University, Harbin, China;Department of Microbiology, Heilongjiang Province Key Laboratory for Immunity and infection, Pathogenic biology, Bio-pharmaceutical Key Laboratory of Ministry of Education, Harbin Medical University, 157 Baojian Road, 150086, Harbin, China;The First Hospital of Qiqihaer City, 30 Gongyuan Road, 161005, Qiqihaer, China;

关键词: Enterobacteriaceae;    Fluoroquinolone resistance;    Gyr;   

DOI  :  10.1186/1471-2334-13-8

 received in 2012-07-24, accepted in 2013-01-02,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundWide use of ciprofloxacin and levofloxacin has often led to increased resistance. The resistance rate to these two agents varies in different clinical isolates of Enterobacteriaceae. Mutations of GyrA within the quinolone resistance-determining regions have been found to be the main mechanism for quinolone resistance in Enterobacteriaceae. It has been shown that only some of the mutations in the gyrA gene identified from clinical sources were involved in fluoroquinolone resistance. Whether different patterns of gyrA mutation are related to antimicrobial resistance against ciprofloxacin and levofloxacin is unclear.MethodsThe minimum inhibitory concentration (MIC) of ciprofloxacin and levofloxacin were determined by the agar dilution method followed by PCR amplification and sequencing of the quinolone resistance determining region of gyrA to identify all the mutation types. The correlation between fluoroquinolone resistance and the individual mutation type was analyzed.ResultsResistance differences between ciprofloxacin and levofloxacin were found in 327 isolates of K. pneumoniae and E. coli in Harbin, China and in the isolates reported in PubMed publications. GyrA mutations were found in both susceptible and resistant isolates. For the isolates with QRDR mutations, the resistance rates to ciprofloxacin and levofloxacin were also statistically different. Among the 14 patterns of alterations, two single mutations (Ser83Tyr and Ser83Ile), and three double mutations (Ser83Leu+Asp87Asn, Ser83Leu+Asp87Tyr and Ser83Phe+Asp87Asn) were associated with both ciprofloxacin and levofloxacin resistance. Two single mutations (Ser83Phe and Ser83Leu) were related with ciprofloxacin resistance but not to levofloxacin. Resistance difference between ciprofloxacin and levofloxacin in isolates harboring mutation Ser83Leu+Asp87Asn were of statistical significance among all Enterobacteriaceae (P<0.001).ConclusionsResistance rate to ciprofloxacin and levofloxacin were statistically different among clinical isolates of Enterobacteriaceae harboring GyrA mutations. Ser83Leu+Asp87Asn may account for the antimicrobial resistance difference between ciprofloxacin and levofloxacin.

【 授权许可】

Unknown   
© Fu et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.