Studies on resistance of Schistosoma to praziquantel XVIII Sensitivity to praziquantel in filial generations of praziquantel-resistant and -sensitive Schistosoma japonicum mixed infections
10.16250/j.32.1374.2020234
- VernacularTitle:血吸虫对吡喹酮抗药性的研究 XⅧ日本血吸虫吡喹酮抗性株与敏感株混合感染子代成虫 对吡喹酮的敏感性
- Author:
Guo-Li QU
1
;
You-Sheng LIANG
1
;
Jian-Rong DAI
1
;
Feng SHI
1
;
Yun-Tian XING
1
;
Xue-Hui SHEN
2
;
Na GUO
1
Author Information
1. Key Laboratory of National Health Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China
2. Dantu District Center for Disease Control and Prevention, Zhenjiang City, Jiangsu Province, China
- Publication Type:Journal Article
- Keywords:
Schistosoma japonicum;
Praziquantel;
Drug resistance;
Median effective dose (ED50)
- From:
Chinese Journal of Schistosomiasis Control
2021;33(5):505-509
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the sensitivity of adult worms of filial generations from praziquantel-resistant and -sensitive Schistosoma japonicum mixed infections to praziquantel. Methods Mice were infected with the cercariae of an experimentally generated praziquantel-resistant S. japonicum isolate [median effective dose (ED50) = 277.4 mg/kg] and a laboratory-maintained praziquantel-sensitive S. japonicum isolate (ED50 = 99.6 mg/kg) at a mixture ratio of 1:1 and 2:1, which was maintained in the laboratory via the mouse-snail cycle for 8 generations. Then, mice were infected with the cercariae of the 8th filial-generation parasite, and grouped 35 days post-infection. Mice in the 5 treatment groups were given praziquantel treatment by gavage at a single oral dose of 37.5, 75, 150, 300 mg/kg and 600 mg/kg, while animals in the control group was administered orally with 2.5% cremophor EL. All mice were sacrificed 14 days post-treatment and adult worms were collected by perfusion of the portal vein. The worm burden reductions and praziquantel ED50 values were calculated. The praziquantel-resistant S. japonicum isolate generated from experimental induction with 12 rounds of praziquantel treatment with sub-curative doses was maintained in the laboratory via the mouse-snail cycle, and mice were infected with the cercariae of the 8th filial-generation parasite. The praziquantel ED50 value against the 8th filial-generation adults was measured. Results After mice were infected with the mixture of cercariae of PZQ-resistant and -sensitive S. japonicum isolates at a ratio of 1:1, the praziquantel ED50 was 135.2 mg/kg against the adults of the 8th filial-generation parasite. After mice were infected with the mixture of cercariae of PZQ-resistant and -sensitive S. japonicum isolates at a ratio of 2:1, the praziquantel ED50 was 129.2 mg/kg against the adults of the 8th filial-generation parasite. In addition, the praziquantel ED50 was 208.4 mg/kg against the adults of the 8th filial-generation S. japonicum without the selection pressure of praziquantel. Conclusions Compared with the experimentally induced praziquantel-resistant S. japonicum isolate, the adult worms of the filial-generation S. japonicum show a reduced sensitivity to praziquantel in the same host following infection with the mixture of cercariae of praziquantel-resistant and -sensitive S. japonicum isolates. The adult worms of the filial generation of the praziquantel-resistant S. japonicum isolate without the selection pressure of praziquantel may still maintain the resistance to praziquantel.
