While PCR is a method of choice for the detection of African trypanosomes in both humans and animals, the expense of this method negates its use as a diagnostic method for the detection of endemic trypanosomiasis in African countries. The loop-mediated isothermal amplification (LAMP) reaction is a method that amplifies DNA with high specificity, efficiency, and rapidity under isothermal conditions with only simple incubators. An added advantage of LAMP over PCR-based methods is that DNA amplification can be monitored spectrophotometrically and/or with the naked eye without the use of dyes. Here we report our conditions for a highly sensitive, specific, and easy diagnostic assay based on LAMP technology for the detection of parasites in the Trypanosoma brucei group (including T. brucei brucei, T. brucei gambiense, T. brucei rhodesiense, and T. evansi) and T. congolense. We show that the sensitivity of the LAMP-based method for detection of trypanosomes in vitro is up to 100 times higher than that of PCR-based methods. In vivo studies in mice infected with human-infective T. brucei gambiense further highlight the potential clinical importance of LAMP as a diagnostic tool for the identification of African trypanosomiasis.
Entomological monitoring of Leishmania infection in leishmaniasis endemic areas offers epidemiologic advantages for predicting the risk and expansion of the disease, as well as evaluation of the effectiveness of control programs. In this study, we developed a highly sensitive loop-mediated isothermal amplification (LAMP) method for the mass screening of sand flies for Leishmania infection based on the 18S rRNA gene. The LAMP technique could detect 0.01 parasites, which was more sensitive than classical PCR. The method was robust and could amplify the target DNA within 1 hr from a crude sand fly template without DNA purification. Amplicon
BackgroundResistance to pyrethroid insecticides involving kdr mutations is widespread in Aedes aegypti (L.) (Diptera: Culicidae) and potentially could impact control efforts in endemic countries. Dengue cases had been sporadic in Burkina Faso for over a decade prior to the 2016–2017 outbreak that resulted in 15,074 suspected cases and 36 deaths, mainly in Ouagadougou. These outbreaks highlighted the lack of information on numerous aspects of the biology, behaviour and insecticide status of local dengue vector populations that are fundamental to vector control.ResultsWe investigated the insecticide resistance profiles and the kdr mutations involved in pyrethroid resistance of Ae. aegypti from Somgandé, a district of Ouagadougou. WHO bioassays revealed that the local Ae. aegypti populations were highly resistant to pyrethroids with mortalities of 15% for permethrin and 37% for deltamethrin. Resistance to carbamates was also detected with mortalities of 55% for propoxur and 90% for bendiocarb, but high mortalities (> 97%) to organophosphates (malathion and fenitrothion) indicated susceptibility. Allele-specific PCR and voltage-gated sodium channel gene sequencing showed a very high frequency (97%) of the F1534C kdr allele whilst the V1016I kdr mutation frequency was 46%. Association of dual-locus kdr mutations was detected for permethrin resistance.ConclusionWe conclude that in this locality of Burkina Faso, Ae. aegypti is resistant to pyrethroid and carbamate insecticides but remains susceptible to organophosphates, providing useful information for possible future control.
Graphical abstractHighlights► All 4 major life cycle stages of Trypanosoma congolense were grown in the lab. ► Relative protein expression among the life cycle stages was studied by iTRAQ MS. ► Several known expression trends were observed and new patterns were identified. ► Special focus is given to lifecycle stage specific surface molecules. ► Six new proteins unique to T. congolense were discovered.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.