Improving stool sample processing and pyrosequencing for quantifying benzimidazole resistance alleles in Trichuris trichiura and Necator americanus pooled eggs

12 páginas, 3 tablas, 3 figuras.There is an urgent need for an extensive evaluation of benzimidazole efcacy in humans. In veterinary science, benzimidazole resistance has been mainly associated with three single-nucleotide polymorphisms (SNPs) in the isotype-1 β-tubulin gene. In this study, we optimized the stool sample processing methodology and resistance allele frequency assessment in Trichuris trichiura and Necator americanus anthelmintic-related SNPs by pyrosequenc‑ ing, and standardized it for large-scale benzimidazole efcacy screening use.This study was funded by the ‘Stopping Transmission Of intestinal Parasites (STOP)’ project (EDCTP2 programme supported by the European Union; RIA2017NCT-1845-STOP). JG was personally supported at the beginning of the work by the Ramón Areces Foundation and is now funded by the Spanish ‘Juan de la Cierva’ Programme, Ministry of Economy and Competitiveness (FJC-2018-38305). MCP is supported by the Junta de Castilla y León and Fondo Social Europeo, and MMV by the Spanish ‘Ramón y Cajal’ Programme, Ministry of Economy and Competitiveness (RYC-2015-18368).Peer reviewe

Ivermectin and albendazole coadministration: opportunities for strongyloidiasis control

7 páginas.In 2020, WHO recognised the importance of strongyloidiasis alongside soil-transmitted helminths (STH) in their 2021–30 roadmap, which aspires to target Strongyloides stercoralis with preventive chemotherapy by use of ivermectin. Combination treatment with both albendazole, the primary drug used to treat STH, and ivermectin, would improve the efficiency of mass drug administration targeting both STH and S stercoralis. In this Personal View, we discuss the challenges and opportunities towards the development of an efficient control programme for strongyloidiasis, particularly if it is to run concurrently with STH control. We argue the need to define the prevalence threshold to implement preventive chemotherapy for S stercoralis, the target populations and optimal dosing schedules, and discuss the added benefits of a fixed-dose coformulation of ivermectin and albendazole. Implementation of an efficient control programme will require improvements to current diagnostics, and validation of new diagnostics, to target and monitor S stercoralis infections, and consideration of the challenges of multispecies diagnostics for S stercoralis and STH control. Finally, the evolution of ivermectin resistance represents a credible risk to control S stercoralis; we argue that genome-wide approaches, together with improved genome resources, are needed to characterise and prevent the emergence of resistance. Overcoming these challenges will help to reduce strongyloidiasis burden and enhance the feasibility of controlling it worldwide.Our group, the Stopping Transmission of intestinal Parasites (STOP) consortium, is funded by the EDCTP2 programme supported by the European Union (RIA2017NCT-1845-STOP). The Barcelona Institute for Global Health (ISGlobal) acknowledges support from the Spanish Ministry of Science and Innovation and State Research Agency through the Centro de Excelencia Severo Ochoa 2019–2023 Program (CEX2018-000806-S) and support from the Generalitat de Catalunya through the CERCA Program. SRD is supported by a UK Research and Innovation Future Leaders Fellowship [MR/T020733/1] and the Wellcome Trust through core funding to the Wellcome Sanger Institute [108413/A/15/D]. MC-P is supported by the Junta de Castilla y León and Fondo Social Europeo. The funders of the study had no role in the manuscript preparation or the decision to publish. The views, opinions, assumptions, or any other information set out in this Personal View are solely those of the authors and should not be attributed to the funders or any person connected with the funders.Peer reviewe

Single-nucleotide polymorphisms in the beta-tubulin gene and its relationship with treatment response to albendazole in human soil-transmitted helminths in southern Mozambique

9 páginas, 2 tablas, 3 figuras.Soil-transmitted helminth (STH) cornerstone control strategy is mass drug administration (MDA) with benzimidazoles. However, MDA might contribute to selection pressure for anthelmintic resistance, as occurred in livestock. The aim of this study is to evaluate the treatment response to albendazole and the relationship with the presence of putative benzimidazole resistance single-nucleotide polymorphisms (SNPs) in the b-tubulin gene of STH in Southern Mozambique. After screening 819 participants, we conducted a cohort study with 184 participants infected with STH in Manhic¸ a district, Southern Mozambique. A pretreatment and a posttreatment stool samples were collected and the STH infection was identified by duplicate Kato-Katz and quantitative polymerase chain reaction (qPCR). Cure rate and egg reduction rates were calculated. Putative benzimidazole resistance SNPs (F167Y, F200T, and E198A) in Trichuris trichiura and Necator americanus were assessed by pyrosequencing. Cure rates by duplicate Kato-Katz and by qPCR were 95.8% and 93.6% for Ascaris lumbricoides, 28% and 7.8% for T. trichiura, and 88.9% and 56.7% for N. americanus. Egg reduction rate by duplicate Kato-Katz was 85.4% for A. lumbricoides, 34.9% for T. trichiura, and 40.5% for N. americanus. Putative benzimidazole resistance SNPs in the b-tubulin gene were detected in T. trichiura (23%) and N. americanus (21%) infected participants at pretreatment. No statistical difference was observed between pretreatment and posttreatment frequencies for none of the SNPs. Although treatment response to albendazole was low, particularly in T. trichiura, the putative benzimidazole resistance SNPs were not higher after treatment in the population studied. New insights are needed for a better understanding and monitoring of human anthelmintic resistance.This work was supported by the British Society for Antimicrobial Chemotherapy (Bsac-2018-0018) and Mundo Sano Foundation (www.mundosano.org). We acknowledge support from the Spanish Ministry of Science and Innovation through the “Centro de Excelencia Severo Ochoa 2019–2023” Program (CEX2018- 000806-S), and support from the “Generalitat de Catalunya” through the CERCA Program. CISM is supported by the Government of Mozambique and the Spanish Agency for International Development (AECID). M. C. P. was funded by Junta de Castilla y Leon and Fondo Social Europeo (LE-135-19). J. G. was personally supported at the beginning of the work by the Ramon Areces Foundation and is now funded by the Spanish “Juan de la Cierva” Programme, Ministry of Economy and Competitiveness (FJC-2018-38305). M. M. V. by the “Ramon y Cajal ” Programme (RYC-2015-18368), Spanish Ministry of Economy, Industry and Competitiveness (MINECO). This project was in part funded by the EDCTP2 program supported by the European Union (Grant no. RIA2017NCT-1845-STOP; www.stoptheworm.org) Horizon 2020 European Union Funding for Research and Innovation.Peer reviewe

In vivo toxicity and efficacy of two diamine and one benzimidazole derivatives against the gastrointestinal nematode Haemonchus contortus

Trabajo presentado al: 28th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP). Dublín. Virtual meeting.MINECO (AEI, FEDER, UE): AGL2016-79813-C2-1R/2R and SAF2017-83575-R and Junta de Castilla y León (JCyL) cofinanced by FEDER, UE [LE020p17]. EVG is funded by JCyL and MMV by Ramón y Cajal Programme (RYC-2015-18368).Peer reviewe

Teladorsagia circumcincta beta tubulin: the presence of the E198L polymorphism on its own is associated with benzimidazole resistance

12 páginas, 4 figuras, 3 tablas.This study was funded by the Spanish “Ramón y Cajal” Programme of the Ministry of Economy and Competitiveness (MMV, RYC-2015-18368), and the Cooperativa Bajo Duero, COBADU. EVG was funded by FPU16/03536, JG by Ramon Areces Foundation, VCGA by Junta de Castilla y León and Fondo Social Europeo (LE082-18), MCP by the Stopping Transmission Of intestinal Parasites (STOP) project (EDCTP2 programme; RIA2017NCT-1845) and MMV by the Spanish “Ramon y Cajal” Programme (RYC-2015-18368)

Molecular analysis of Strongyloides stercoralis beta-tubulin gene and the possible effects on albendazole efficacy

Trabajo presentado al: 12th European Congress on Tropical Medicine and International Health (ECTMIH). Norway. 28 september-1 octubrer. Virtual meeting.Peer reviewe