NovelKdrmutations (K964R and A943V) in pyrethroid‐resistant populations ofTriatoma mazzottiiandTriatoma longipennisfrom Mexico and detoxifying enzymes

Abstract

Although having five different ways of transmission the vector-borne is the principal way of transmission of Chagas disease, which involves insects of the subfamily Triatominae (Hemiptera: Reduviidae). Nineteen of the 31 species that occur in Mexico are associated with humans, and all are capable of transmitting the disease. Pyrethroids are the insecticides recommended for the control of these vectors in Mexico. We determined the susceptibility to the pyrethroids deltamethrin and permethrin of peridomestic populations of Triatoma mazzottii Usinger and two populations of Triatoma longipennis Usinger in comparison with a reference strain for each species. Bioassays were performed for the determination of the LD for both field populations and reference strains. A maximum of 27 fold resistance to deltamethrin was observed in T. mazzottii, meanwhile, for permethrin, T. longipennis from Jalisco show the highest value of 3.19 fold. There was significantly increased activity of esterases in field populations in comparison with their corresponding reference strain. The results of the search of kdr mutations related to the resistance to deltamethrin and permethrin in the evaluated species show the presence of mutations in the field populations, as is the case with individuals of T. mazzottii, for which the mutation was found A943V, and for the two populations of T. longipennis included in this study, we report the presence of the kdr mutation K964R. Evaluation of the various mechanisms involved in resistance to pyrethroids in triatomines from Mexico could guide us to the real justification for insecticide resistance monitoring.

Improved vector control of Triatoma infestans limited by emerging pyrethroid resistance across an urban-to-rural gradient in the Argentine Chaco

“…In addition to T. infestans , other triatomine species have displayed reduced susceptibility to pyrethroids elsewhere, including Rhodnius prolixus from Venezuela [ 62 ] and Colombia [ 63 ], T. sordida from Minas Gerais [ 64 ], and Triatoma mazzotti and Triatoma longipennis from Mexico [ 65 ]. Whether such reduced susceptibility levels actually cause control failures is a key question across triatomine species and settings, and entail linking the outcomes of discriminating dose bioassays to village-level house infestation patterns.…”

Deltamethrin resistance in Chagas disease vectors colonizing oil palm plantations: implications for vector control strategies in a public health-agriculture interface

“…These enzymes are involved in metabolic mechanisms associated to pyrethroid resistance [3]. The technique by Valle et al [31] was used with some modifications for triatomines by Davila-Barboza et al [32].…”

First report of two kdr mutations L1014F/S in natural populations ofTriatoma pallidipennisStal andTriatoma picturataUsinger vectors of Chagas disease in Mexico

“…Kdr mutations are distributed in the sodium channel ( vgsc ), more specifically in domain II between the transmembrane segments IIS4–IIS6, and have been reported in more than 50 species of insects of economic or medical importance (Rinkevich et al ). The first kdr mutations reported in triatomines are L1014F and L925I associated with resistance to deltamethrin in Triatoma infestans , and more recently the mutations K964R and A943V for T. mazzottii and T. longipennis, respectively, related to resistance to permethrin and deltamethrin (Fabro et al , Capriotti et al , Davila‐Barboza et al ). In the present study, the sequences of the region IIS4–IIS6 of the vgsc of field populations T. pallidipennis and T. picturata from Mexico were obtained to identify the presence of kdr mutations.…”