Persistence of PCR-positive tissue in benznidazole-treated mice with negative blood parasitological and serological tests in dual infections with Trypanosoma cruzi stocks from different genotypes
Persistence of PCR-positive tissue in benznidazole-treated mice with negative blood parasitological and serological tests in dual infections with Trypanosoma cruzi stocks from different genotypes
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DOI：
10.1093/jac/dkn092
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发表时间：
2008-06-01
影响因子：
5.2
通讯作者：
Lana, M.
中科院分区：
文献类型：
--
作者：
Martins, H. R.;Figueiredo, L. M.;Lana, M.
目的：评估不同的方法，以更好地确定混合感染双重克氏锥虫基因型的BALB/c小鼠在苯并硝唑治疗后的早期治疗后治愈标准。方法：根据经典治愈标准，采用寄生虫学方法[新鲜血液检查（FBE）、血培养（BC）和血液PCR]和血清学方法[常规血清学（CS-ELISA）和非常规血清学（NCS-FC-ALTA）]将动物分为未治愈（TNC = 76.4%）、治愈（TC = 12.5%）和分离（DIS = 11.1%）。组织也通过PCR进行评估。结果：FBE仅能在18.1%的TNC中检测到未治愈的寄生虫血症，BC和血液PCR分别检测到79.1%和97.2%的TNC治疗失败。CS-ELISA在治疗后3个月内不应使用，因为它可能导致假阴性结果。在苯并硝唑治疗3个月后，NCS-FC-ALTA对治疗小鼠的分组更有效。在TNC组中，尽管在几个宿主组织中观察到pcr阳性组织的频率降低，但尽管存在克氏t型组合，但也观察到阳性组织的增加。所有TC动物至少有两个组织pcr阳性结果。结论：NSC-FC-ALTA和血液PCR是早期检测急性小鼠克氏锥虫感染治疗失败最合适的方法。此外，我们的数据显示BC阳性高度依赖于克氏t型组合。此外，我们的研究结果表明，在经苯并硝唑治疗后被认为治愈的动物组织中进行的PCR检测仍然检测到克氏体DNA，这很可能表明残留感染。
Objectives: To assess different methodologies to better define an early post-therapeutic cure criterion after benznidazole treatment in BALB/c mice following mixed infection with dual Trypanosoma cruzi genotypes.Methods: According to the classical cure criteria, animals were classified as treated not cured (TNC = 76.4%), treated cured (TC = 12.5%) and dissociated (DIS = 11.1%) using parasitological [fresh blood examination (FBE), blood culture (BC) and blood PCR] and serological methods [conventional serology (CS-ELISA) and non-conventional serology (NCS-FC-ALTA)]. Tissues were also evaluated by PCR.Results: FBE was able to detect patent parasitaemia in only 18.1% of TNC and therapeutic failure was detected in 79.1% and 97.2% of TNC by BC and blood PCR, respectively. CS-ELISA should not be used before 3 months after treatment since it may lead to false-negative results. At 3 months after treatment with benznidazole, NCS-FC-ALTA was more efficient for categorizing the groups of treated mice. In the TNC group, although a decreased frequency of PCR-positive tissue was observed in several host tissues, increased positivity was also observed, despite the T. cruzi genotype combination. All TC animals presented at least two positive tissue-PCR results.Conclusions: Our results confirm that NSC-FC-ALTA and blood PCR are the most suitable methods to early detect therapeutic failure in acute murine T. cruzi infection. Additionally, our data show that BC positivity is highly dependent upon the T. cruzi genotype combination. Moreover, our findings demonstrated that PCR tests performed on tissues from animals considered cured after benznidazole treatment still detected T. cruzi DNA, most probably indicating residual infection.