Prevalence and molecular characterization of methicillin-resistant Staphylococcus aureus with mupirocin, fusidic acid and/or retapamulin resistance
Prevalence and molecular characterization of methicillin-resistant Staphylococcus aureus with mupirocin, fusidic acid and/or retapamulin resistance
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接受经皮冠状动脉介入治疗的患者不同肾小球滤过率公式的预后：来自多中心观察队列的见解
DOI：
10.1186/s12872-020-01621-y
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发表时间：
2020-06-29
期刊：
影响因子：
4.2
通讯作者：
Liu, Qingzhong
中科院分区：
文献类型：
--
作者：
Chen, Wenjing;He, Chunyan;Liu, Qingzhong
背景我国耐甲氧西林金黄色葡萄球菌（MRSA）对莫匹罗星（MUP）、夫西地酸（FA）和瑞他莫林（RET）的耐药情况尚不清楚。本研究旨在检测来自中国东部的1206株MRSA临床分离株对这三种抗生素的耐药性。表型MUP、FA和RET抗性通过最小抑菌浓度（MIC）确定，基因型通过PCR和DNA测序确定，所述PCR和DNA测序包括mupA/B、fusB-D、cfr、vgaA/Av/A（LC）/B/C/E、lsaA-C/E和salA以及ileS、fusA/E、rplC和23 S RNA V结构域中的突变。耐药菌株的遗传特征进行了脉冲场凝胶电泳（PFGE）和多位点序列分型（MLST）。结果总体MRSA MUP，FA和RET耐药率较低（分别为5. 1，1. 0和0. 3%）。MupA是MUP高水平耐药的机制。所有低水平MUP耐药分离株在IleS中均存在可疑突变N213 D;其中2株报告了对Rossman折叠有影响的额外V588 F突变。高水平耐药菌株的FA机制主要为L461 K、H457 Q、H457 Y和V90 I等FusA突变，其中多数菌株还含有fusC;而低水平耐药菌株均含有fusB。除1个菌株检测到lsaE基因外，其余菌株均未检测到其它抗性机制。PFGE分型16种（A-P），其中B型最常见（49/76，64.5%），其次为E型和G型（各4/76，5.3%），C型和M型（各3/76，3.9%）。MLST将所有耐药菌株分为15个ST型。ST 764（24/76，31.6%）、ST 630（11/76，14.5%）、ST 239（9/76，11.8%）和ST 5（7/76，9.2%）为主要类型。结论MUP、FA和RET对MRSA具有较强的抗菌活性。获得性基因和染色体携带基因突变是MUP和FA耐药的原因;但一些RET耐药分离株的机制仍有待进一步阐明。此外，还应加强对耐甲氧西林金黄色葡萄球菌MUP的监测，防止因克隆扩张而导致耐药性升高。
BackgroundThe data on the prevalence of resistance to mupirocin (MUP), fusidic acid (FA) and retapamulin (RET) in methicillin-resistant Staphylococcus aureus (MRSA) from China are still limited. This study aimed to examine these three antibiotics resistance in 1206 MRSA clinical isolates from Eastern China. Phenotypic MUP, FA and RET resistance was determined by minimum inhibitory concentrations (MICs), and genotypic by PCR and DNA sequencing of the mupA/B, fusB-D, cfr, vgaA/Av/A(LC)/B/C/E, lsaA-C/E and salA and mutations in ileS, fusA/E, rplC, and 23S RNA V domain. The genetic characteristics of resistance isolates were conducted by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).ResultsOverall MRSA MUP, FA and RET resistance was low (5.1, 1.0 and 0.3%, respectively). MupA was the mechanism of high-level MUP resistance. All low-level MUP resistance isolates possessed an equivocal mutation N213D in IleS; of these, 2 reported an additional V588F mutation with an impact on the Rossman fold. FusA mutations, such as L461K, H457Q, H457Y and V90I were the primary FA mechanisms among high-level resistance isolates, most of which also contained fusC; however, all low-level resistance strains carried fusB. Except lsaE gene detected in one isolate, no other resistance mechanisms tested were found among RET-resistant isolates. Additionally, sixteen PFGE types (A-P) were observed, among which type B was the most common (49/76, 64.5%), followed by types E and G (4/76, 5.3% each) and types C and M (3/76, 3.9% each). All resistant strains were divided into 15 ST types by MLST. ST764 (24/76, 31.6%), ST630 (11/76, 14.5%), ST239 (9/76, 11.8%) and ST5 (7/76, 9.2%) were the major types. PFGE type B isolates with the aforementioned STs were mainly found in mupirocin resistant isolates.ConclusionsMUP, FA and RET exhibited highly activity against the MRSA isolates. Acquired genes and chromosome-borne genes mutations were responsible for MUP and FA resistance; however, the mechanism for some RET-resistant isolates remains to be further elucidated. Also, the surveillance to MUP in MRSA should be strengthened to prevent elevated resistance due to the expansion of clones.