Establishment of culture conditions for survival of Histomonas meleagridis in transit.

Fresh ceca samples from turkeys in North Carolina infected with Histomonas meleagridis were collected at necropsy, inoculated into warmed Dwyers medium, and sent by overnight courier to our laboratory at The University of Georgia. Further incubation at 40 C yielded positive cultures from all four samples. PCR and DNA sequencing confirmed the presence of H. meleagridis. To further establish conditions for survival in transit, we infected turkeys with H. meleagridis, euthanatized the birds 10 days postinfection, and allowed carcasses to incubate at room temperature for either 2 or 24 hr. After incubation, samples of cecal contents (0.5 g) were placed in Dwyers medium and held at 4, 25, or 30 C for 6, 18, 24, 48, 72, 96, or 120 hr, simulating holding conditions during transit. Samples were placed in a 40 C incubator at the specified times and examined daily for histomonad growth by light microscopy. Positive histomonad growth was detected from cecal samples obtained from the 2-hr incubated carcass and from cultures held at 30 C for 6, 18, 24, 48, and 72 hr. No growth was seen from cultures held at 25 or 4 C or at any temperature from the carcass allowed to incubate for 24 hr at room temperature. These results suggest that positive isolation can be made from field samples, provided that material is collected at warm temperatures and transported rapidly to the laboratory.