El-Badawy Mohamed F, Abou-Elazm Fatma I, Omar Mohamed S, El-Naggar Mostafa E, Maghrabi Ibrahim A
Department of Microbiology and Immunology, Faculty of Pharmacy, University of Sadat City, Sadat City, Menoufia, 32897, Egypt.
Department of Microbiology and Immunology, Faculty of Pharmacy, Misr University for Science and Technology, 6th of October City, Egypt.
Infect Drug Resist. 2021 Nov 12;14:4739-4756. doi: 10.2147/IDR.S324707. eCollection 2021.
() is one of the most important nosocomial pathogens responsible for a wide range of infections.
This study aimed to investigate the existence of the plasmidic genes encoding for aminoglycoside modifying enzymes (AMEs), 16S rRNA methyltransferases (RMT), and the altered dihydropetroate synthase (DHPS) encoded by the gene among clinical isolates collected from Taif, Kingdom of Saudi Arabia (KSA). The mutations in and genes were also investigated.
Forty clinical isolates were investigated for their susceptibility to ten antibiotics. The plasmid DNA was extracted and screened for nine genes encoding for aminoglycoside resistance in addition to the gene. The clonal relatedness was determined by random amplified polymorphic DNA (RAPD)-PCR. Mutation in and the genes were detected by capillary electrophoresis sequencing (CES).
All isolates were in which 42.5% of them exhibited a high level of aminoglycoside resistance (HLAR). The most prevalent AMEs and RMT encoding genes were , the two gene variants [ and ], and in which 90%, 87.5%, 85%, and 45% of isolates tested positive, respectively. The other investigated aminoglycoside resistant encoding genes, namely , and rmtB, were not detected. Only 15% of isolates harbored the gene. RAPD-PCR classified the 40 isolates into three clusters in which cluster II was the main cluster. DNA sequencing revealed that 34.29% (12/35) of isolates tested positive for were found to harbor a common missense mutation in position 102 indicating a novel allelic variant named . Also, DNA sequencing revealed three missense mutations in the gene.
This is the first Saudi study to investigate the plasmid borne aminoglycoside and sulfonamide resistance genes among clinical isolates. A novel allelic variant for was detected in addition to novel mutations in the gene.
（）是导致多种感染的最重要的医院病原体之一。
本研究旨在调查从沙特阿拉伯王国塔伊夫收集的临床分离株中编码氨基糖苷修饰酶（AMEs）、16S rRNA甲基转移酶（RMT）以及由基因编码的改变的二氢蝶酸合酶（DHPS）的质粒基因的存在情况。还对和基因中的突变进行了研究。
对40株临床分离株进行了对十种抗生素的敏感性调查。提取质粒DNA并除基因外筛选九个编码氨基糖苷抗性的基因。通过随机扩增多态性DNA（RAPD）-PCR确定克隆相关性。通过毛细管电泳测序（CES）检测和基因中的突变。
所有分离株均为，其中42.5%表现出高水平的氨基糖苷抗性（HLAR）。最常见的AMEs和RMT编码基因是、两种基因变体[和]、和，分别有90%、87.5%、85%和45%的分离株检测呈阳性。未检测到其他研究的氨基糖苷抗性编码基因，即和rmtB。只有15%的分离株携带基因。RAPD-PCR将40株分离株分为三个簇，其中簇II是主要簇。DNA测序显示，检测呈阳性的分离株中有34.29%（12/35）在第102位存在一个常见的错义突变，表明存在一种名为的新型等位基因变体。此外，DNA测序还揭示了基因中的三个错义突变。
这是沙特阿拉伯第一项调查临床分离株中质粒携带的氨基糖苷和磺胺抗性基因的研究。除了基因中的新突变外，还检测到了一种新的等位基因变体。
