分析我国山东地区临床分离的纹带棒状杆菌对常用药物的敏感性，并对其耐药机制进行探讨。收集该省某三甲医院临床样本，用哥伦比亚血平板培养基对纹带棒状杆菌进行分离培养，用微量肉汤稀释法检测12种常用抗生素对纹带棒状杆菌的最低抑菌浓度(minimal inhibitory concentration, MIC)。采用聚合酶链式反应(polymerase chain reaction，PCR)对耐药菌株的耐药基因[aph(3”)-Ⅰb、aph(6)-Ⅰd、aac(6’)-Ⅰb, tetW, ermX, gyrA]进行扩增、测序比对，以探讨相关的耐药机制。通过实时荧光定量PCR(quantitative real-time PCR, qPCR)对耐药基因ermX、tetW进行定量分析，采用公式2－ΔΔCt计算基因相对表达量差异倍数。结果显示，共分离出纹带棒状杆菌83株，且均为多重耐药菌。对万古霉素、利奈唑胺表现为完全敏感；对红霉素、环丙沙星、克林霉素表现出完全耐药，对四环素的耐药率为86.7%(72/83)，对庆大霉素的耐药率为38.6%(32/83)；ermX基因的检出率为100%(83/83)，tetW基因的检出率为88.0%(73/83)，aph(3”)-Ⅰb基因的检出率为36.1%(30/83)，aph(6)-Ⅰd基因的检出率为37.3%(31/83)，aac(6’)-Ⅰb基因的检出率为15.7%(13/83)。ermX和tetW基因的相对表达量均有所变化，但变化不明显。内在型耐药(cMLS)是菌株对红霉素耐药的潜在机制。结果提示，本研究调查医院的纹带棒状杆菌耐药严重，耐药谱较为广泛，须引起医院和实验室的重视。
魏孔娇1
,
王嘉正2
,
邱小彤3
,
徐帅3
,
朱雄4
,
李欢4
,
王晓霞4
,
王成玲1
,
范仕弘1
,
韩李超3
,
刘志国3
,
李振军1
,
3
. 纹带棒状杆菌耐药特征研究[J]. 微生物与感染, 2021
, 16(6)
: 384
-390
.
DOI: 10.3969/j.issn.1673-6184.2021.06.003
To reveal the drug resistance and its mechanism preliminarily of clinical isolates of Corynebacterium striatum in Shandong Province of China, 83 isolates of Corynebacterium striatum were collected from clinical specimens during March 2017 and June 2020 in a tertiary hospitals from Shandong. The minimal broth dilution method was used to detect the minimal inhibitory concentration.The aminoglycoside modifying enzyme genes [aph(3”)-Ⅰb、aph(6)-Ⅰd、aac(6’)-Ⅰb], the ribosomal protective protein gene of tetracycline resistance (tetW), the ribosomal methylase gene (ermX), quinolone resistance genes (gyrA) were tested by polymerase chain reaction(PCR). The PCR products were sequenced and compared with BLAST.Quantitative real-time PCR (qPCR) was used to analyze the drug-resistant genes ermX and tetW quantitatively, and formula 2－ΔΔCt was used to calculate the relative expression of genes.All the tested Corynebacterium striatum were proved as multi-drug resistant strains. The MDR-Cs showed completely sensitive to vancomycin and linezolid and completely resistance to erythromycin, ciprofloxacin and clindamycin, the detection rate of tetracycline, gentamicin were 86.7% (72/83)and 38.6%(32/83), respectively. The detection rate of ermX and tetW were 100%(83/83) and 88%(73/83), the detection rate of aph(3”)-Ⅰb, aph(6)-Ⅰd, aac(6’)-Ⅰb were 36.1%(30/83), 37.3%(31/83) and 15.7%(13/83), respectively. The resistance phenotype of the strain to erythromycin is cMLS. The drug resistance spectrum is relatively broad in this study, which needs to be paid attention from hospitals and laboratories.
