Testing for drug resistance in Dirofilaria immitis from Australian dogs

This study utilised phenotypic and genotypic assays to determine the presence of macrocyclic lactone resistant Dirofilaria immitis in Australia. We surveyed dogs from Queensland and New South Wales, Australia for the presence of D. immitis infection using an antigen test, quantitative Modified Knotts test, and qPCR targeting both D. immitis and the D. immitis symbiont Wolbachia. A phenotypic assay utilising a microfilarial suppression test was coupled with Illumina amplicon next generation sequencing of filtered microfilariae for SNPs previously associated with macrocyclic lactone resistance in isolates from the USA.