Multiple mechanisms contributing to ciprofloxacin resistance among Gram negative bacteria causing infections to cancer patients.
Multiple mechanisms contributing to ciprofloxacin resistance among Gram negative bacteria causing infections to cancer patients.
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DOI：
10.1038/s41598-018-30756-4
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发表时间：
2018-08-16
影响因子：
4.6
通讯作者：
Aboshanab KMA
中科院分区：
文献类型：
--
作者：
Hamed SM;Elkhatib WF;El-Mahallawy HA;Helmy MM;Ashour MS;Aboshanab KMA
氟喹诺酮类药物已被用于预防癌症患者的感染，但其对耐药机制的影响仍需进一步研究。为了阐明引起癌症患者感染的革兰氏阴性病原体对环丙沙星（CIP）的耐药机制，对169株分离株进行了调查。肉汤微量稀释法检测显示89.3%的分离株具有高水平的CIP抗性。使用PCR和DNA测序在15个选择的分离株中分析靶位点突变。其中gyrA突变（密码子83和87）和parC突变（密码子80和84）占93.3%。对所有分离株进行了质粒介导的喹诺酮类耐药基因（PMQR）筛查，其中56.8%的分离株在这方面呈阳性。PMQR基因以aac（6′）-Ib-cr为主（42.6%），qnr基因占32.5%。这包括26.6%的qnrS和6.5%的qnrB。ERIC-PCR检测qnr阳性菌株的克隆性，结果显示绝大多数菌株为非克隆性。研究了外排泵抑制剂CCCP对CIP MIC的降低作用，结果显示，在18.3%的分离株中观察到外排活性的贡献。此外，大多数氟喹诺酮类耐药机制中检测到革兰氏阴性菌株从癌症患者中恢复。与PMQR和外排活性相比，靶位点突变对CIP耐药性的影响最大。
Fluoroquinolones have been used for prophylaxis against infections in cancer patients but their impact on the resistance mechanisms still require further investigation. To elucidate mechanisms underlying ciprofloxacin (CIP) resistance in Gram-negative pathogens causing infections to cancer patients, 169 isolates were investigated. Broth microdilution assays showed high-level CIP resistance in 89.3% of the isolates. Target site mutations were analyzed using PCR and DNA sequencing in 15 selected isolates. Of them, all had gyrA mutations (codons 83 and 87) with parC mutations (codons 80 and 84) in 93.3%. All isolates were screened for plasmid-mediated quinolone resistance (PMQR) genes and 56.8% of them were positive in this respect. Among PMQR genes, aac(6′)-Ib-cr predominated (42.6%) while qnr genes were harbored by 32.5%. This comprised qnrS in 26.6% and qnrB in 6.5%. Clonality of the qnr-positive isolates using ERIC-PCR revealed that most of them were not clonal. CIP MIC reduction by CCCP, an efflux pump inhibitor, was studied and the results revealed that contribution of efflux activity was observed in 18.3% of the isolates. Furthermore, most fluoroquinolone resistance mechanisms were detected among Gram-negative isolates recovered from cancer patients. Target site mutations had the highest impact on CIP resistance as compared to PMQRs and efflux activity.
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影响因子：
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作者：
Cremet, L.;Caroff, N.;Corvec, S.
通讯作者：
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影响因子：
11.8
作者：
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Wingard, John R.
DOI：
10.1016/j.ijantimicag.2004.11.012
发表时间：
2005-04-01
影响因子：
10.8
作者：
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通讯作者：
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影响因子：
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影响因子：
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作者：
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通讯作者：
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