Genotyping of Histomonas meleagridis isolates based on Internal Transcribed Spacer-1 sequences

C-profiling is a novel genotyping method for protozoan pathogens, based on polymerase chain reaction and sequencing of AT-rich Internal Transcribed Spacer-1 sequences. It was applied to various Histomonas meleagridis isolates originating from outbreaks of histomoniasis in six Dutch turkey and chicken flocks. Three different H. meleagridis genotypes were identified. Type I and type II were associated with clinical disease. In two flocks, both having recovered from an outbreak of histomoniasis, a type III strain was found that was also morphologically slightly different from the type I and type II isolates. C-profiling is a promising technique to differentiate between H. meleagridis subtypes, making it useful for epidemiological studies.