Rai S, Niranjan D K, Kaur T, Singh N P, Hada V, Kaur I R
Department of Microbiology , University College of Medical Sciences and Guru Teg Bahadur Hospital, Dilshad Garden, Delhi, India.
Indian J Med Microbiol. 2015 Jan-Mar;33(1):21-4. doi: 10.4103/0255-0857.148371.
Linezolid is an effective drug against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). We describe the emergence of linezolid resistance in MRSA and VRE from India.
One MRSA and two VRE strains were isolated from a patient on linezolid therapy of one week duration. All three isolates were resistant to linezolid with minimal inhibitory concentrations (MIC) ≥4 mg/L. The 746-bp region flanking the possible G2576U mutation on the corresponding DNA from the 23S rRNA was amplified by polymerase chain reaction (PCR) and amplicons were sequenced for all the three isolates. Conjugation experiments using the linezolid resistant MRSA (LRMRSA) and linezolid resistant VRE (LRVRE) isolates as donors and wild strains of corresponding genera as recipients were performed.
The MRSA isolate had the classical G2576U mutation. High quality value scores in the sequencing software validated the mutation. Conjugation studies did not indicate presence of transferable resistance for linezolid. Sequencing did not indicate presence of any mutation in the two LRVRE isolates.
This is the first report from India citing resistance in Staphylococcus and Enterococcus against Linezolid.
利奈唑胺是一种针对耐甲氧西林金黄色葡萄球菌（MRSA）和耐万古霉素肠球菌（VRE）的有效药物。我们描述了印度MRSA和VRE中利奈唑胺耐药性的出现情况。
从一名接受为期一周利奈唑胺治疗的患者身上分离出一株MRSA和两株VRE菌株。所有三株分离株对利奈唑胺均耐药，最低抑菌浓度（MIC）≥4mg/L。通过聚合酶链反应（PCR）扩增23S rRNA相应DNA上可能的G2576U突变侧翼的746bp区域，并对所有三株分离株的扩增子进行测序。以耐利奈唑胺的MRSA（LRMRSA）和耐利奈唑胺的VRE（LRVRE）分离株为供体，相应属的野生菌株为受体进行接合实验。
MRSA分离株具有典型的G2576U突变。测序软件中的高质量值分数验证了该突变。接合研究未表明利奈唑胺存在可转移耐药性。测序未表明两株LRVRE分离株存在任何突变。
这是印度首次报道葡萄球菌和肠球菌对利奈唑胺耐药的情况。
