02923nas a2200289 4500008004100000022002500041245021700066210006900283260001600352300001400368490000700382520191600389653001402305653002302319653002402342653001502366653001502381100001902396700002202415700002302437700002502460700002302485700001902508700002102527700002102548856006402569 2021 eng d a2231-0916, 0972-898800aIn vitro experiments of Pediculus humanus capitis (Phthiraptera: Pediculidae) resistance to permethrin and 6-paradol in East Jakarta: Detoxification enzyme activity and electron microscopic changes in lice0 aIn vitro experiments of iPediculus humanus capitisi Phthiraptera cNov-30-2021 a3065-30750 v143 a

Background and Aim: Pediculus humanus capitis, the human head louse, remains a global health problem. This study evaluated the resistance of head lice to permethrin and 6-paradol mediated by in vitro detoxification enzyme activity experiments and to describe physical changes in the lice using scanning electron microscopy (SEM).

Materials and Methods: The adult stages of P. h. capitis were collected from patients exposed to 1% permethrin and three different concentrations of 6-paradol (0.00005%, 0.0001%, and 0.00015%) using a filter paper diffusion bioassay. Healthy P. h. capitis adults served as the control. The in vitro bioassays were conducted after 10, 20, 30, and 60 min of exposure. The activities of acetylcholinesterase (AChE), glutathione S-transferase (GST), and oxidase were analyzed. Physical changes in the lice were analyzed using SEM.

Results: Permethrin and 6-paradol exhibited low toxicity against the lice. At 60 min, 1% permethrin had killed 36.7% of the lice present, while 6-paradol had killed 66.7-86.7%. Permethrin induced significantly elevated AChE, GST, and oxidase activity; 6-paradol also caused significantly elevated AChE, GST, and oxidase activity. Permethrin did not cause any ultrastructural morphological changes on the lice, while 6-paradol severely damaged the head, thorax, respiratory spiracles, and abdomen of the dead lice.

Conclusion: This in vitro experimental of P. h. capitis is the first study to report P. h. capitis in East Jakarta shows complete resistance to permethrin and 6-paradol, and to describe the associated increase in AChE, GST, and oxidase activity. It was observed that 6-paradol severely damaged the head, thorax, respiratory spiracles, and abdomen of the dead lice.

10a6-paradol10adetoxifying enzyme10aelectron microscopy10aPermethrin10aresistance1 aSubahar, Rizal1 aSusanto, Lisawati1 aAidilla, Rachmanin1 aAulia, Annisa, Putri1 aYulhasri, Yulhasri1 aWinita, Rawina1 aLubis, Nadar, S.1 aSari, Ika, Puspa uhttp://www.veterinaryworld.org/Vol.14/November-2021/29.html