L3 larvae

  • 文章类型: Journal Article
    人类念珠菌病是一种食源性疾病,在世界范围内已越来越多地报道,它是由食用感染了念珠菌属人畜共患线虫的生的或未煮熟的海鲜引起的,1845.最常报道的物种之一,无论是在鱼类宿主还是人类患者中,是Anisakissimplexsensustricto(s.s.),它分布在北太平洋和大西洋的一些全球主要渔场中。为了阐明体内温度对这种寄生虫的影响,A.simplexs.s.的第三阶段幼虫在虹鳟鱼(Oncorhynchusmykiss)和莫桑比克罗非鱼(Oreochromismossambicus)的体腔中接受手术攻击。然后在6周和12周后分析幼虫存活和组织迁移。结果表明,27和33℃的幼虫存活率低于3、9、15和21℃。此外,在9°C时观察到向身体肌肉的迁移最高。这些结果表明,A.simplexs.s.的第三阶段幼虫更适应实验挑战的鱼类的较低温度,这可能证明它在寒冷的北方水域的分布是合理的。
    Human anisakiasis is a foodborne disease that has been increasingly reported worldwide and is caused by the consumption of raw or undercooked seafood infected with zoonotic nematodes of the genus Anisakis Dujardin, 1845. One of the most frequently reported species, both in fish paratenic hosts as well as in human patients, is Anisakis simplex sensu stricto (s.s.), which is distributed within some of the globe\'s main fishing grounds in the North Pacific and Atlantic oceans. In order to clarify the influence of temperature on this parasite in vivo, third-stage larvae of A. simplex s.s. were surgically challenged in the body cavities of rainbow trouts (Oncorhynchus mykiss) and Mozambique tilapias (Oreochromis mossambicus). Larval survival and tissue migration were then analyzed after 6 and 12 weeks. The results showed that survival rates of larvae were lower at 27 and 33 °C than at 3, 9, 15 and 21 °C. Also, migration to the body muscle was observed to be highest at 9 °C. These results suggest that third-stage larvae of A. simplex s.s. are more adapted to lower temperatures in experimentally challenged fish, which may justify its distribution in cold northern waters.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    温度对鸡蛋发育的影响,最近在体外检查了海洋寄生线虫Anisakissimplexsensustricto(s.s.)和A.pegreffii的孵化幼虫和L3幼虫。A.simplexs.s.的卵在3-25°C孵化,A.pegreffii的卵在3-27°C孵化。孵化前几天在A.simplexs.s.中在25°C下2天和在3°C下35-36天之间变化。在A.pegrefii中在27°C下2至3天和在3°C下65天之间变化。A.simplexs.s.的孵化率在3至25°C的温度下保持较高,但在27°C时降至0%。相比之下,A.pegreffii的温度最低,特别是在3°C时,但也在27°C。在A.simplexs.s.中,孵化幼虫的平均50%存活率从25°C的5.3天到9°C的82.3天不等。而在A.pegreffii中,它的范围从27°C的1.2天到9°C的77.2天。A.pegreffii的L3幼虫表现出比A.simplexs.s.更高的存活率和活性,特别是在20和25℃。这些结果表明,A.simplexs.s.的早期阶段更适应较低的温度,而A.pegreffii的早期阶段更耐受温暖的环境,这可能与它们在日本和欧洲的分布模式相对应。
    Effects of temperature on development of eggs, recently hatched larvae and L3 larvae of the marine parasitic nematodes Anisakis simplex sensu stricto (s.s.) and A. pegreffii were examined in vitro. The eggs of A. simplex s.s. hatched at 3-25 °C and those of A. pegreffii hatched at 3-27 °C. Days before hatching varied between 2 days at 25 °C and 35-36 days at 3 °C in A. simplex s.s. and between 2 and 3 days at 27 °C and 65 days at 3 °C in A. pegreffii. Hatching rates of A. simplex s.s. were maintained high at temperatures between 3 and 25 °C but decreased to 0% at 27 °C. In contrast, those of A. pegreffii were lowest particularly at 3 °C, but also at 27 °C. The mean 50% survivals of hatched larvae ranged from 5.3 days at 25 °C to 82.3 days at 9 °C in A. simplex s.s., while in A. pegreffii it ranged from 1.2 days at 27 °C to 77.2 days at 9 °C. L3 larvae of A. pegreffii exhibited higher survival rates and activity than those of A. simplex s.s., particularly at 20 and 25 °C. These results suggest that the early stages of A. simplex s.s. are more adapted to lower temperatures whereas those of A. pegreffii are more tolerant to warm environments, which may correspond to their distribution patterns in Japan and Europe.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    Suitable and scalable in vitro culture conditions for parasite maintenance are needed to foster drug research for loiasis, one of the neglected tropical diseases which has attracted only limited attention over recent years, despite having important public health impacts. The present work aims to develop adequate in vitro culture systems for drug screening against both microfilariae (mf) and infective third-stage larvae (L3) of Loa loa.
    In vitro culture conditions were evaluated by varying three basic culture media: Roswell Park Memorial Institute (RPMI-1640), Dulbecco\'s modified Eagle\'s medium (DMEM) and Iscove\'s modified Dulbecco\'s medium (IMDM); four sera/proteins: newborn calf serum (NCS), foetal bovine serum (FBS), bovine serum albumin (BSA) and the lipid-enriched BSA (AlbuMax® II, ALB); and co-culture with the Monkey Kidney Epithelial Cell line (LLC-MK2) as a feeder layer. The various culture systems were tested on both mf and L3, using survival (% motile), motility (T90 = mean duration (days) at which at least 90% of parasites were fully active) and moulting rates of L3 as the major criteria. The general linear model regression analysis was performed to assess the contribution of each variable on the viability of Loa loa L3 and microfilarie. All statistical tests were performed at 95% confidence interval.
    Of the three different media tested, DMEM and IMDM were the most suitable sustaining the maintenance of both L. loa L3 and mf. IMDM alone could sustain L3 for more than 5 days (T90 = 6.5 ± 1.1 day). Serum supplements and LLC-MK2 co-cultures significantly improved the survival of parasites in DMEM and IMDM. In co-cultures with LLC-MK2 cells, L. loa mf were maintained in each of the three basic media (T90 of 16.4-19.5 days) without any serum supplement. The most effective culture systems promoting significant moulting rate of L3 into L4 (at least 25%) with substantial maintenance time were: DMEM + BSA, DMEM + NCS, DMEM-AlbuMax®II, DMEM + FBS all in co-culture with LLC-MK2, and IMDM + BSA (1.5%), DMEM + FBS (10%) and DMEM + NCS (5%) without feeder cells. DMEM + 1% BSA in co-culture scored the highest moulting rate of 57 of 81 (70.37%). The factors that promoted L. loa mf viability included feeder cells (β = 0.490), both IMDM (β = 0.256) and DMEM (β = 0.198) media and the protein supplements NCS (β = 0.052) and FBS (β = 0.022); while for L. loa L3, in addition to feeder cells (β = 0.259) and both IMDM (β = 0.401) and DMEM (β = 0.385) media, the protein supplements BSA (β = 0.029) were found important in maintaining the worm motility.
    The findings from this work display a range of culture requirements for the maintenance of Loa loa stages, which are suitable for developing an effective platform for drug screening.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

公众号