Histophagous scuticociliatids (Ciliophora) parasitizing turbot Scophthalmus maximus:: morphology, in vitro culture and virulence
Histophagous scuticociliatids (Ciliophora) parasitizing turbot Scophthalmus maximus:: morphology, in vitro culture and virulence
复制标题
DOI：
10.14411/fp.2004.021
复制
发表时间：
2004-06-01
影响因子：
1.6
通讯作者：
Arán, J
中科院分区：
文献类型：
--
作者：
Alvarez-Pellitero, P;Palenzuela, O;Arán, J
由食组织纤毛虫引起的全身性纤毛虫病是养殖大菱形目鱼类的一种严重病害。在西班牙、法国和葡萄牙的4个不同养殖场的6次家畜暴发期间，从被寄生的大比目鱼身上分离到6个纤毛虫分离物。6个菌株在ATCC1651 MA或添加L-15的培养基上进行周期性继代培养，获得无菌培养。在基础培养基或海水中，寄生虫可以长期饥饿生存，不会有明显的增殖。在适宜的培养基中，菌株A和B的生长动力学非常相似，但温度有明显的影响。形态研究表明，所有的分离物都有共同的特征，可以将它们归入PhilasteridesKahl，1931或Miamiens Thompson et Moewus，1964。然而，来自四个农场地点的分离物在16个分类学相关的形态计量学特征上的配对比较显示出显著的统计学差异。这可以对不同的物种或菌株进行区分。对A、B两个分离株对健康大比目鱼的致病力进行了多次试验。在长期体外培养后，菌株A的毒力差异尤其明显，35-42代后，菌株A的毒力明显减弱，而菌株B在20-42代后毒力增强。强调了进一步研究的必要性，以确认这种毒力变异及其在大比目鱼皮肤球虫病的发病机制和预防中的意义。
Systemic ciliatosis caused by histophagous ciliates constitutes a serious disease of cultured turbot. Six ciliate isolates were obtained from parasitized turbot during six epizootics at four different farms located in Spain, France and Portugal. Axenic cultures of the six isolates were obtained by periodical subculturing in ATCC 1651MA or supplemented L-15 media. In basal media or seawater, the parasites could survive starving for long periods with no apparent proliferation. In adequate media, growth kinetics was found to be very similar for isolates A and B, with a clear influence of temperature. Morphological studies demonstrated that all isolates share common features that allows their assignment to either Philasterides Kahl, 1931 or Miamiensis Thompson et Moewus, 1964. However, statistically significant differences were evident in pairwise comparisons of the isolates from the four farm sites in 16 taxonomically relevant morphometric features. This could allow the discrimination of different species or strains. Virulence of isolates A and B for healthy turbot was tested in several experiments. Differences in the virulence were especially evident after long-term in vitro culturing, isolate A being clearly attenuated after 35-42 passages, whereas isolate B became more virulent after 20-42 passages. The need of further studies to confirm such virulence variability and its implications in pathogenesis and prevention of turbot scuticociliatoses is stressed.