effects of flubendazole and its metabolites on the larval development of Haemonchus contortus (Nematoda: Trichostrongylidae): an in vitro study

• Published in: Helminthologia 2010-12, Vol.47 (4), p.269-272
• Main Authors: Bártíková, H, Skálová, L, Lamka, J, Szotáková, B, Várady, M
• Format: Article
• Language: English
• Subjects: Anthelmintic agents; anthelmintic resistance; Antiparasitic agents; benzimidazoles; Biomedical and Life Sciences; Biomedicine; biotransformation; Developmental stages; Ecology; Haemonchus contortus; In vitro methods and tests; Larvae; Larval development; larval development test; Larval stage; Lethal limits; Life Sciences; Medical Microbiology; Metabolites; Microbiology; Mortality causes; Nematoda; Nematodes; Research Note; Resistance factors; Thiabendazole; Toxicity tests; Trichostrongylidae; Zoology
• ISSN: 0440-6605; 1336-9083
• DOI: 10.2478/s11687-010-0042-7

The anthelmintic effects of flubendazole (FLU), its two main metabolites reduced flubendazole (FLU-R) and hydrolyzed flubendazole (FLU-H), and thiabendazole (TBZ) were compared using an in vitro larval development test in two isolates of Haemonchus contortus, a fully susceptible isolate (HCS) and a multi-resistant isolate (HCR). Results were quantified as 50 % lethal concentration (LC₅₀), 99 % lethal concentration (LC₉₉), efficacy factor (EF), and resistance factor (RF). For HCS, both LC₅₀ and LC₉₉ of FLU were lower than those of the reference TBZ. The anthelmintic activity of FLU-R in HCS and HCR was 13 and 6 times lower than the activity of FLU, respectively. The anthelmintic activity of FLU-H was negligible (approximately 363-853 times lower) compared to that of FLU. Although a marked resistance of the HCR isolate to TBZ was confirmed, only a low tolerance to FLU-R and slightly higher tolerance to FLU were found.