Myint Chomar Kaung, Asato Yutaka, Yamamoto Yu-ichi, Kato Hirotomo, Bhutto Abdul M, Soomro Farooq R, Memon Muhamad Z, Matsumoto Jun, Marco Jorge D, Oshiro Minoru, Katakura Ken, Hashiguchi Yoshihisa, Uezato Hiroshi
Division of Dermatology, Department of Organ-oriented Medicine, School of Medicine, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
J Dermatol. 2008 Feb;35(2):76-85. doi: 10.1111/j.1346-8138.2008.00419.x.
The exact species and/or strains of Leishmania parasites involved strongly influence the clinical and epidemiological features of leishmaniasis, and current knowledge of those influences and relationships is inadequate. We report that cytochrome b (cyt b) gene sequencing identified causal Leishmania parasites of 69 cutaneous leishmaniasis cases in Pakistan over a 3-year period. Of 21 cases in highland areas (Quetta city, Balochistan province), 16 (76.2%) were identified as Leishmania (L.) tropica and five (23.8%) as Leishmania (L.) major. Of 48 cases from lowland areas, cities/villages in Indus valley in Sindh and Balochistan provinces, 47 (97.9%) were identified as L. (L.) major and one (2.1%) as L. (L.) tropica. Statistical analysis (Fisher's exact test) revealed a significant difference (P < 0.0001) in the distribution of the two species by altitude; L. (L.) major is predominant in lowland and L. (L.) tropica at highland areas. The present result enriched our earlier finding, based on the first year's cultured parasite data, that only L. (L.) tropica was found in highland areas and only L. (L.) major in lowland areas. Among Leishmania samples analyzed, three types of cyt b polymorphism of L. (L.) major were found, including 45 (86.5%) cases of type I, six (11.5%) of type II and one (2%) of type III. We report for the first time on the presence of polymorphisms in L. (L.) major (types I, II and III) based on species identification using cyt b gene sequencing from clinical samples. Moreover, we found no correlation between clinical presentation (wet-, dry- and/or mixed-types of cutaneous lesions) and causal Leishmania parasites.
利什曼原虫寄生虫的确切种类和/或菌株对利什曼病的临床和流行病学特征有很大影响，而目前对这些影响和关系的了解还不够充分。我们报告，通过细胞色素b（cyt b）基因测序，在3年时间里确定了巴基斯坦69例皮肤利什曼病病例的致病利什曼原虫寄生虫。在高地地区（俾路支省奎达市）的21例病例中，16例（76.2%）被鉴定为热带利什曼原虫（Leishmania (L.) tropica），5例（23.8%）为硕大利什曼原虫（Leishmania (L.) major）。在来自低地地区（信德省和俾路支省印度河流域的城市/村庄）的48例病例中，47例（97.9%）被鉴定为硕大利什曼原虫，1例（2.1%）为热带利什曼原虫。统计分析（Fisher精确检验）显示，两种利什曼原虫在不同海拔地区的分布存在显著差异（P < 0.0001）；硕大利什曼原虫在低地地区占主导，而热带利什曼原虫在高地地区占主导。目前的结果丰富了我们早期基于第一年培养的寄生虫数据得出的发现，即高地地区仅发现热带利什曼原虫，低地地区仅发现硕大利什曼原虫。在所分析的利什曼原虫样本中发现了硕大利什曼原虫的三种细胞色素b多态性类型，包括I型45例（86.5%）、II型6例（11.5%）和III型1例（2%）。我们首次基于临床样本的细胞色素b基因测序进行物种鉴定，报告了硕大利什曼原虫（I型、II型和III型）中存在多态性。此外，我们发现临床表现（皮肤病变的湿性、干性和/或混合型）与致病利什曼原虫寄生虫之间没有相关性。
