Çulha Gülnaz, Kaya Tuğba, Gülbol Duran Gülay, Urhan Küçük Meral, Doğramacı Asena Çiğdem, Tiyekli Çelik Dilek
Hatay Mustafa Kemal University Faculty of Medicine, Department of Parasitology, Hatay, Turkey.
Hatay Mustafa Kemal University Faculty of Medicine, Department of Medical Biology, Hatay, Turkey.
Mikrobiyol Bul. 2019 Oct;53(4):408-418. doi: 10.5578/mb.68692.
Leishmaniasis is a parasitic disease that is transmitted to humans by the bites of infected female phlebotomine sandflies. In the diagnosis of cutaneous leishmaniasis (CL), in the smear samples, the demonstration of the parasite by microscope remains a gold standard method. However, it becomes difficult to diagnose the parasite since the number of amastigotes in chronic cases with a lesion of one year or longer is very low. Due to many factor such as patients primarily do not to take any notice these lesions in their bodies, do not apply to health institutions or late applied, receive wrong treatment; the diagnosis and treatment are delayed. In addition, it is been worse prognosis by add secondary infection to lesions and wounds become chronic. For this reason, molecular methods are used in addition to microscopic examination in chronic suspected CL cases. It was aimed to reveal of the molecular diagnostic value in chronic suspected CL cases by polymerase chain reaction (PCR) in the smear belonging to Turkish patients that reported to be evaluated clinically because it can not be seen Leishmania amastigotes in microscopic examination. Smear of 50 Turkish patients who were clinically reported of the evaluation of chronic CL were selected. These samples were smears belonging to suspected CL patients that applied Hatay Mustafa Kemal University, Faculty of Medicine, Parasitology laboratory from different polyclinics and were decided to be evaluated clinically as a result of microscopic examination because they came from endemic regions (such as Hassa, Altınözü, Yayladağı). DNA was isolated from selected samples and PCR was performed using 13A, 13B primers targeting the kinetoplastid DNA (kDNA) region. The samples found positive by PCR were typed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis using LITSR and L5.8S primers targeting internal transcribed spacer (ITS-1) region. Of the 50 smear samples, 17 (34%) were determined positive with 13A, 13B primers targeting the kinetoplastid DNA (kDNA) region. Positive samples were also found to be positive with LITSR and L5.8S primers targeting ITS-1 region. The PCR products obtained from PCR with ITS-1 gene region were digested with the restriction endonucleases BsuRI (HaeIII). As a result of PCR-RFLP analysis, it was determined that 11 of Leishmania tropica, one of Leishmania major and five of Leishmania infantum/donovani out of 17 samples. Chronic CL can be confused with skin diseases such as sarcoidosis, tuberculosis, malignant tumors. In particular, chronic CL cases can be escaped the attention for many reasons such as failure to diagnose correctly, insufficient microscope experience, fail to see due to low number of parasites. For this reason, it was concluded that PCR, which is a molecular method, should be used in chronic suspected CL samples which are negative for the parasite by microscopic examination.
利什曼病是一种寄生虫病,通过受感染的雌性白蛉叮咬传播给人类。在皮肤利什曼病(CL)的诊断中,在涂片样本中,通过显微镜显示寄生虫仍然是金标准方法。然而,由于病程一年或更长时间的慢性病例中无鞭毛体数量非常少,因此难以诊断出寄生虫。由于许多因素,如患者最初没有注意到身体上的这些病变,没有前往医疗机构就诊或就诊较晚,接受了错误的治疗;导致诊断和治疗延迟。此外,病变继发感染且伤口变为慢性会使预后更差。因此,对于慢性疑似CL病例,除了显微镜检查外还使用分子方法。本研究旨在通过聚合酶链反应(PCR)揭示在临床评估的土耳其患者涂片中慢性疑似CL病例的分子诊断价值,因为在显微镜检查中未见利什曼原虫无鞭毛体。选择了50例临床报告为慢性CL评估的土耳其患者的涂片。这些样本是来自不同门诊、应用于哈塔伊穆斯塔法·凯末尔大学医学院寄生虫学实验室的疑似CL患者的涂片,由于它们来自流行地区(如哈萨、阿尔廷奥祖、亚伊拉达ğı),经显微镜检查后决定进行临床评估。从选定的样本中分离DNA,并使用靶向动质体DNA(kDNA)区域的13A、13B引物进行PCR。通过PCR检测为阳性的样本,使用靶向内部转录间隔区(ITS-1)区域的LITSR和L5.8S引物,通过聚合酶链反应-限制性片段长度多态性(PCR-RFLP)分析进行分型。在50份涂片样本中,17份(34%)使用靶向动质体DNA(kDNA)区域的13A、13B引物检测为阳性。阳性样本使用靶向ITS-1区域的LITSR和L5.8S引物检测也为阳性。用限制性内切酶BsuRI(HaeIII)消化从ITS-1基因区域PCR获得的PCR产物。通过PCR-RFLP分析确定,17份样本中有11份为热带利什曼原虫,1份为硕大利什曼原虫,5份为婴儿利什曼原虫/杜氏利什曼原虫。慢性CL可能与结节病、结核病、恶性肿瘤等皮肤病混淆。特别是,慢性CL病例可能由于多种原因而未被注意到,如诊断错误、显微镜经验不足、寄生虫数量少而未被发现。因此,得出结论,对于显微镜检查寄生虫为阴性的慢性疑似CL样本,应使用作为分子方法的PCR。