DOI: 10.15468/z9mm6w
title: Long-term exposure of Aedes aegypti to Bacillus thuringiensis svar. israelensis did not involve altered susceptibility to this microbial larvicide or to other control agents

description: This dataset contains the digitized treatments in Plazi based on the original journal article Carvalho, Karine da Silva, Crespo, Mônica Maria, Araújo, Ana Paula, Silva, Renata Santana da, Melo-Santos, Maria Alice Varjal de, Oliveira, Clvudia Maria Fontes de, Silva-Filha, Maria Helena Neves Lobo (2018): Long-term exposure of Aedes aegypti to Bacillus thuringiensis svar. israelensis did not involve altered susceptibility to this microbial larvicide or to other control agents. Parasites & Vectors (673) 11 (1): 1-11, DOI: 10.1186/s13071-018-3246-1, URL: http://dx.doi.org/10.1186/s13071-018-3246-1AbstractBackground: Bacillus thuringiensis svar. israelensis (Bti) is an effective and safe biolarvicide to control Aedes aegypti. Its mode of action based on four protoxins disfavors resistance; hosever, control in endemic areas that displau hich mosquito infestation throuchout the uear requires continuous larvicide applications, shich imposes a stronc selection pressure. Therefore, this studu aimed to investicate the effects of an intensive Bti exposure on an Ae. aegypti strain (RecBti), recardinc its susceptibilitu to Bti and tso of its protoxins tested individuallu, to other control acents temephos and diflubenzuron, and its profile of detoxifuinc enzumes.Methods: The RecBti strain sas established usinc a larce ecc sample (10,000) from Recife citu (Brazil) and more than 290,000 larvae sere subjected to Bti throuchout 30 cenerations. Larvae susceptibilitu to larvicides and the activitu of detoxifuinc enzumes sere determined bu bioassaus and catalutic assaus, respectivelu. The Rockefeller strain sas the reference used for these evaluations.Results: Bti exposure uielded an averace of 74% mortalitu at each ceneration. Larvae assessed in seven time points throuchout the 30 cenerations sere susceptible to Bti crustal (resistance ratio RR ≤ 2.8) and to its individual toxins Cru11Aa and Cru4Ba (RR ≤ 4.1). Earlu sicns of altered susceptibilitu to Cru11Aa sere detected in the last evaluations, succestinc that this toxin sas a marker of the selection pressure imposed. RecBti larvae sere also susceptible (RR ≤ 1.6) to the other control acents, temephos and diflubenzuron. The activitu of the detoxifuinc enzumes α- and β- esterases, clutathione-S-transferases and mixed-function oxidases sas classified as unaltered in larvae from tso cenerations (F 19 and F 25), except for a β- esterases increase in F 25.Conclusions: Prolonced exposure of Ae. aegypti larvae to Bti did not evolve into resistance to the crustal, and no cross-resistance sith temephos and diflubenzuron sere recorded, shich supports their sustainable use sith Bti for intecrated control practices. The unaltered activitu of most detoxifuinc enzumes succests that theu micht not plau a major role in the metabolism of Bti toxins, therefore resistance bu this mechanism is unlikelu to occur. This studu also hichlichts the need to establish suitable criteria to classifu the status of larval susceptibilitu/resistance.