Preliminary data on Ascaridia galli infections in Gallus gallus domesticus and the development of a specific primer based on the NADH dehydrogenase subunit 4.

One major problem of chicken (Gallus gallus domesticus) farming was various parasitic infections, especially Ascaridia galli that can cause the Ascaridiosis and is commonly found worldwide. The purpose of this study was to investigate the epidemiological situation of gastrointestinal tract parasitic infections and to develop species-specific primer for A. galli detection. A total of 247 chicken gastrointestinal tract specimens from 5 fresh markets in Bangkok. The species-specific primers of A. galli were manually designed using the mitochondrial genome at the NADH dehydrogenase subunit 4 (MT-ND 4) gene. As a result, PCR assays were optimized for the specific PCR product approximately 198 bp with the optimal temperature of 51 °C. In addition, sensitivity tests provided the detection of adult and egg stages at the minimum concentrations of 156.3 ng and 2.8 ng (70 eggs), respectively. This research can be used as preliminary information regarding the epidemic situation of gastrointestinal tract infections in chickens and detection of A. galli infection in definitive hosts, which plans programs for the effective control and prevention of parasitic infections.

The prevalence of cercarial infection and development of a duplex PCR for detection of the cercarial stage of Haplorchis taichui and H. pumilio in first intermediate hosts from Chai Nat province, Thailand.

This study aimed to investigate the prevalence of cercarial infections in freshwater snails collected from the Chai Nat province of Central Thailand. Moreover, we aimed to develop a duplex PCR technique, using the ITS2 and candidate MT-ND1 gene, to determine the dissemination of H. taichui and H. pumilio, respectively. Six types of cercariae were discovered with an overall prevalence of 4.71% (59/1,252). The parapleurolophocercous cercariae were demonstrated to be the dominant type, infecting only Melanoides tuberculata snails. The duplex PCR was optimized for specific amplification of ITS2 for H. taichui (115 bp) and MT-ND1 for H. pumilio (335 bp). Both specific primers confirmed the specificity of the duplex PCR reaction, with no cross-reactivity with other heterophyids or related species. In addition, this duplex PCR could be used to detect co-infection at a concentration of 3.0 ng/µL. For the molecular identification, 9 of 22 parapleurolophocercous cercaria specimens in Chai Nat province generated the specific DNA fragment of H. pumilio. These results proved that the MT-ND1 gene is a species-specific method for heterophyid detection and provides a rapid method for identification based on larval and adult stages of H. taichui and H. pumilio in their intermediate and/or definitive hosts in the infected area.