Song Yajun, Roumagnac Philippe, Weill François-Xavier, Wain John, Dolecek Christiane, Mazzoni Camila J, Holt Kathryn E, Achtman Mark
Environmental Research Institute, University College Cork, Lee Road, Cork, Ireland.
J Antimicrob Chemother. 2010 Aug;65(8):1631-41. doi: 10.1093/jac/dkq175. Epub 2010 May 28.
Decreased susceptibility to fluoroquinolones has become a major problem for the successful therapy of human infections caused by Salmonella enterica, especially the life-threatening typhoid and paratyphoid fevers.
By using Luminex xTAG beads, we developed a rapid, reliable and cost-effective multiplexed genotyping assay for simultaneously detecting 11 mutations in gyrA, gyrB and parE of S. enterica serovars Typhi and Paratyphi A that result in nalidixic acid resistance (Nal(R)) and/or decreased susceptibility to fluoroquinolones.
This assay yielded unambiguous single nucleotide polymorphism calls on extracted DNA from 292 isolates of Salmonella Typhi (Nal(R) = 223 and Nal(S) = 69) and 106 isolates of Salmonella Paratyphi A (Nal(R) = 24 and Nal(S) = 82). All of the 247 Nal(R) Salmonella Typhi and Salmonella Paratyphi A isolates were found to harbour at least one of the target mutations, with GyrA Phe-83 as the most common one (143/223 for Salmonella Typhi and 18/24 for Salmonella Paratyphi A). We also identified three GyrB mutations in eight Nal(S) Salmonella Typhi isolates (six for GyrB Phe-464, one for GyrB Leu-465 and one for GyrB Asp-466), and mutations GyrB Phe-464 and GyrB Asp-466 seem to be related to the decreased ciprofloxacin susceptibility phenotype in Salmonella Typhi. This assay can also be used directly on boiled single colonies.
The assay presented here would be useful for clinical and reference laboratories to rapidly screen quinolone-resistant isolates of Salmonella Typhi and Salmonella Paratyphi A, and decipher the underlying genetic changes for epidemiological purposes.
对氟喹诺酮类药物敏感性降低已成为成功治疗由肠炎沙门氏菌引起的人类感染的一个主要问题，尤其是危及生命的伤寒和副伤寒热。
通过使用Luminex xTAG磁珠，我们开发了一种快速、可靠且经济高效的多重基因分型检测方法，用于同时检测伤寒沙门氏菌和甲型副伤寒沙门氏菌gyrA、gyrB和parE中的11个突变，这些突变导致对萘啶酸耐药（Nal(R)）和/或对氟喹诺酮类药物敏感性降低。
该检测方法对从292株伤寒沙门氏菌（Nal(R)=223株，Nal(S)=69株）和106株甲型副伤寒沙门氏菌（Nal(R)=24株，Nal(S)=82株）中提取的DNA进行单核苷酸多态性检测，结果明确。在247株Nal(R)伤寒沙门氏菌和甲型副伤寒沙门氏菌分离株中，均发现至少携带一种目标突变，其中GyrA第83位苯丙氨酸突变最为常见（伤寒沙门氏菌中为143/223，甲型副伤寒沙门氏菌中为18/24）。我们还在8株Nal(S)伤寒沙门氏菌分离株中鉴定出3个GyrB突变（GyrB第464位苯丙氨酸突变6株，GyrB第465位亮氨酸突变和GyrB第466位天冬氨酸突变各1株），GyrB第464位苯丙氨酸突变和GyrB第466位天冬氨酸突变似乎与伤寒沙门氏菌中环丙沙星敏感性降低的表型有关。该检测方法也可直接用于煮沸后的单个菌落。
本文介绍的检测方法将有助于临床和参考实验室快速筛选耐喹诺酮类的伤寒沙门氏菌和甲型副伤寒沙门氏菌分离株，并为流行病学目的解读潜在的基因变化。
