RESISTANCE TO LEVAMISOLE AND CROSS-RESISTANCE BETWEEN PYRANTEL AND LEVAMISOLE IN OESOPHAGOSTOMUM-QUADRISPINULATUM AND OESOPHAGOSTOMUM-DENTATUM OF PIGS
RESISTANCE TO LEVAMISOLE AND CROSS-RESISTANCE BETWEEN PYRANTEL AND LEVAMISOLE IN OESOPHAGOSTOMUM-QUADRISPINULATUM AND OESOPHAGOSTOMUM-DENTATUM OF PIGS
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DOI：
10.1016/0304-4017(90)90022-4
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发表时间：
1990-08-01
影响因子：
2.6
通讯作者：
NANSEN, P
中科院分区：
文献类型：
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作者：
BJORN, H;ROEPSTORFF, A;NANSEN, P
采用体内对照的方法，测定了两株四刺棘口吸虫和具牙齿吸虫对左旋咪唑和吡喃酮的抗药性。最近从一个商业猪群中分离到一株(LEM)，该猪群的母猪在分娩后2周内的粪便中出现了大量的Strongyle蛋，并在生产前1周用制造商推荐的剂量率使用左旋咪唑治疗。在这个农场，左旋咪唑作为唯一的驱虫剂至少使用了7年。在这群牛中使用吡喃酮治疗也表明了对这种药物的交叉耐药性。对该菌株的混合种群进行了体内对照试验。排卵量减少率为-573.3%(P>；0.001)，四鞭金线虫减虫率为44.5%(P>；005)，齿纹伊蚊减虫率为96.4%(P<；0.001)。吡喃酮对该药存在交叉耐药，对四片棘豆和齿状棘豆的Fcr分别为10.4%(P>；0.05)和64.5%(P>；0.05)，WCR分别为64.5%(P>；0.05)和90.7%(P<；0.05)。从另一个商品猪群中分离到另一株菌株(VJ)，该猪群每年给药4次，持续至少8年。该菌株对吡喃酮的抗性为43.8%(P>；0.05)，对四翅原虫和牙齿原虫的Fcr和WCR分别为65.9%(P>；0.05)和49.4%(P>；0.05)。然而，这两个物种都对左旋咪唑敏感。我们的结果表明，左旋咪唑产生了左旋咪唑耐药性，并自动产生了对吡喃酮的耐药性，而用吡喃酮进行选择只会导致对这种药物的耐药性。这些发现与这两种食管口线虫在猪大肠中的位置以及这类驱虫剂的作用方式有关。
Two strains of Oeosphagostomum spp., consisting of both O. quadrispinulatum and O. dentatum, were subjected to a controlled in vivo assay for resistance of levamisole and pyrantel by comparison with susceptible isolates. One strain (LEM) was recently isolated from a commercial herd, where sows showed high numbers of strongyle eggs in faeces within 2 weeks of farrowing and following treatment with levamisole at the manufacturer''s recommended dose rate 1 week before farrowing. Levamisole had been used as the sole anthelmitic for treatment for at least 7 years on this farm. Treatment with pyrantel in this herd also indicated cross-resistance to this drug. A mixed population of O. quadrispinulatum and O. dentatum of this strain was subjected to controlled in vivo assays. Faecal egg count reduction (FECR) was found to be -573.3% (P > 0.05) and worm count reductions (WCR) of O. quadrispinultum and O. dentatum were estimated as 44.5% (P > 0.05) and 96.4% (P < 0.001), respectively. Treatment with pyrantel showed that cross-resistance existed to this drug, with FECR of 10.4% (P > 0.05) and WCR of 64.5% (P > 0.05) and 90.7% (P < 0.05) for O. quadrispinulatum and O. dentatum, respectively. Another strain (VJ) was isolated from another commercial pig herd, which was dosed with pyrantel citrate four times a year for at least 8 years. This strain showed resistance to pyrantel, with FECR of 43.8% (P > 0.05) and WCR of 65.9% (P > 0.05) and 49.4% (P > 0.05) for O. quadrispinulatum and O. dentatum, respectively. However, both species were susceptible to levamisole. Our results suggested that levamisole gave rise to levamisole resistance and automatically conferred resistance to pyrantel, whereas selection with pyrantel only resulted in resistance to this drug alone. These findings are discussed in relation to the location of the two species of Oesophagostomum in the large intestine of pigs and the mode of action of this class of anthelmintics.