he increase in antibiotic resistance raises concerns that, at least in some regions, we are returning to a pre-antibiotic era, in particular for Gram-negative infections. The increased prevalence of extended-spectrum serine-β-lactamases (SBLs) and metallo-β-lactamases (MBLs) means β-lactams are increasingly ineffective in treating Gram-negative infections 1,2 . The advent of mobilized colistin resistance-1 in 2015 3 and transferable tigecycline resistance genes (tetX3-tetX5) in 2019 4 , which mediate resistance to colistin and tigecycline, respectively, means all clinically vital antibiotics for serious Gram-negative infections are compromised.
Infections with parasitic nematodes are among the most significant of the neglected tropical diseases affecting about a billion people living mainly in tropical regions with low economic activity.
The most effective current strategy to control nematode infections involves large scale treatment programs with anthelmintic drugs. This strategy is at risk from the emergence of drug resistant parasites. Parasitic nematodes also affect livestock, which are treated with the same limited group of anthelmintic drugs. Livestock parasites resistant to single drugs, and even multi-drug resistant parasites, are appearing in many areas. There is therefore a pressing need for new anthelmintic drugs.
Here we use the nematode
Caenorhabditis elegans
as a model for parasitic nematodes and demonstrate that sinefungin, a competitive inhibitor of methyltransferases, causes a delay in development and reduced fecundity, and inhibits spliced leader
trans
-splicing. Spliced leader
trans
-splicing is an essential step in gene expression that does not occur in the hosts of parasitic nematodes, and is therefore a potential target for new anthelmintic drugs.
We have exploited the ability of sinefungin to inhibit spliced leader
trans
-splicing to adapt a green fluorescent protein based reporter gene assay that monitors spliced leader
trans
-splicing for high-throughput screening for new anthelmintic compounds. We have established a protocol for robust high-throughput screening, combining mechanical dispensing of living
C. elegans
into 384- or 1536- well plates with addition of compounds using an acoustic liquid dispenser, and the detection of the inhibition of SL
trans
-splicing using a microplate reader. We have tested this protocol in a first pilot screen and envisage that this assay will be a valuable tool in the search for new anthelmintic drugs.
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.