Saravia N G, Weigle K, Segura I, Giannini S H, Pacheco R, Labrada L A, Goncalves A
Centro Internacional de Investigaciones Médicas Cali, Colombia.
Lancet. 1990 Aug 18;336(8712):398-402. doi: 10.1016/0140-6736(90)91945-7.
Strains of Leishmania braziliensis subspecies isolated from initial and recurrent lesions in 24 patients from the Pacific coast of Colombia were examined for distinguishing polymorphisms by enzyme electrophoresis, restriction endonuclease analysis of kDNA, and molecular karyotyping of nuclear DNA. Recurrent strains from 12 patients (50%) were identical to the initially infecting strain by all methods of characterisation. Phenotypic and genotypic identity, together with clinical data, support endogenous reactivation as the mechanisms of recurrent disease in these 12 patients. 5 of the 24 (22%) recurrent strains differed from the initial strain by all methods. The remaining 7 strain pairs, not separated by enzyme polymorphisms, showed differing schizodeme and/or karyotype profiles. Patients whose recurrent lesions were caused by strains different from those causing the initial lesions had a significantly longer disease-free interval than patients whose lesions were caused by identical strains. Recurrent lesions occurred further from initial lesions in the former than in the latter group. Exogenous reinfection is the most plausible explanation for recurrences due to disparate organisms. These findings have important implications for both treatment evaluation and vaccination strategies for American tegumentary leishmaniasis.
对从哥伦比亚太平洋沿岸24名患者的初始和复发病变中分离出的巴西利什曼原虫亚种菌株进行了检测，通过酶电泳、kDNA的限制性内切酶分析以及核DNA的分子核型分析来鉴别多态性。通过所有鉴定方法，12名患者（50%）的复发菌株与最初感染的菌株相同。表型和基因型的一致性，以及临床数据，支持内源性再激活是这12名患者复发性疾病的机制。24株复发菌株中有5株（22%）在所有方法上均与初始菌株不同。其余7对菌株，未通过酶多态性分离，显示出不同的裂殖体型和/或核型图谱。复发病变由与引起初始病变不同的菌株引起的患者，其无病间隔时间明显长于病变由相同菌株引起的患者。在前一组中，复发病变比后一组离初始病变更远。外源性再感染是由不同生物体引起复发的最合理的解释。这些发现对美洲皮肤利什曼病的治疗评估和疫苗接种策略都具有重要意义。
