Comparative analysis of a chemotherapy effect on the cuticular surface of Wuchereria bancrofti adult worms in vivo

Abstract

Wuchereria bancrofti is the main species responsible for human lymphatic filariasis and remains a major public health problem in tropical countries around the world. Diethylcarbamazine (DEC) has been used for decades in control programs as an effective microfilaricide, although its efficacy in killing adult worms is only around 50% and its direct mode of action is unclear. Recently, in an attempt to control and eliminate lymphatic filariasis, WHO has recommended albendazole (ALB), a broad-spectrum anthelminthic combined with DEC or ivermectin for mass treatment. Some studies have shown that DEC alone blocks oogenesis, fertilization in adult worms, and loss of the microfilarial sheath of several filarial species, whereas ALB is thought to target nematode tubulin. So far, the direct effect of ALB in combination with DEC has not been described in W. bancrofti adult worms. Therefore, the purpose of this study is to investigate by scanning electron microscopy if DEC coadministered with ALB can induce in vivo morphological alterations of the W. bancrofti adult worm surface obtained from a patient in whom the adult worm remained alive, checked serially by ultrasonography for 2 months after antifilarial treatment. Our analysis demonstrates that worms presented morphologic alterations in some regions suggesting cuticular surface damage. On the other hand, adult worms that were recovered from a patient treated with DEC alone after a single dose did not show such any abnormalities.

Surface of the filarial parasite Setaria digitata and the structural changes on treatment with Triton X-100

“…The striations on the cuticle are actually the annulations of the cuticle. The results obtained showed that the structure of parasite wall is similar to the surface of W. bancrofti (Araujo, 1995;Oliveira-Menezes, 2007). The results support the use of S. digitata as a model organism for research in filariasis.…”

Anthelmintic activity ofAcacia oxyphyllastem bark againstAscaridia galli

“…Surface distortion and loss of regular cuticular annulations were also observed on Brugia malayi Brug (Tippawangkosol et al, 2004). Adult Wuchereria bancrofti Wucherer & Bancroft subjected to albendazole and diethylcarbamazine combination therapy exhibited swollen cuticle, formation of spherical and spike-like projections at the anterior region, and leaf-like expansion on the general cuticle (Oliveira-Menezes et al, 2007).…”

Comparison between the effect of Lawsonia inermis and flubendazole on Strongyloides species using scanning electron microscopy

“…Morphological alterations as antihelminthic outcome was also observed by Oliveira-Menezes et al (2007) who demonstrated cuticular changes of the W. bancrofti adult worm surface obtained from a patient treated with diethylcarbamazine (DEC) co-administered with albendazole (ALB). On the other hand, adult worms that were recovered from a patient treated with DEC alone after a single dose did not show such any abnormalities.…”

“…It is not possible, however, to understand whether or not these alterations have biological significance on the parasite itself or in the host-parasite interplay at longer time if would have an accumulative damage after yearly mass treatment as discussed by Ottesen et al (1997) and Oliveira-Menezes et al (2007) commenting on comparative analysis of a chemotherapy effect on the cuticular surface of Wuchereria bancrofti adult worms.…”