Preliminary genetic evidence of two different populations of Opisthorchis viverrini in Lao PDR

Abstract

Opisthorchis viverrini is a major public health concern in Southeast Asia. Various reports have suggested that this parasite may represent a species complex, with genetic structure in the region perhaps being dictated by geographical factors and different species of intermediate hosts. We used four microsatellite loci to analyze O. viverrini adult worms originating from six species of cyprinid fish in Thailand and Lao PDR. Two distinct O. viverrini populations were observed. In Ban Phai, Thailand, only one subgroup occurred, hosted by two different fish species. Both subgroups occurred in fish from That Luang, Lao PDR, but were represented to very different degrees among the fish hosts there. Our data suggest that, although geographical separation is more important than fish host specificity in influencing genetic structure, it is possible that two species of Opisthorchis, with little interbreeding, are present near Vientiane in Lao PDR.

Infection Dynamics of Opisthorchis viverrini Metacercariae in Cyprinid Fishes from Two Endemic Areas in Thailand and Lao PDR

“…Moreover, our recent population genetic study suggests that species of cyprinid fish make little contribution to genetic diversity of O. viverrini in Thailand and Lao PDR. 28 Thus, the reason for O. viverrini occurring predominantly in certain species of fish reminds to be determined.…”

“…Therefore, moderate or heavy infections in human and animal hosts are likely to be a consequence of cumulative and or long-term exposure to infection, which is probably rare as most humans have light infections. 37,38 Recently, Pitaksakulrat et al 28 used microsatellite makers for population genetic studies with different species of fish hosts in Thailand and Lao PDR. The result showed O. viverrini was separated into two clusters with one cluster from C. armatus, H. siamensis, and B. gonionotus from Lao PDR and the other cluster from P. brevis from Lao PDR.…”

Current Perspectives on Opisthorchiasis Control and Cholangiocarcinoma Detection in Southeast Asia

“…Furthermore, these studies showed that self-fertilization and/or a clonal distribution commonly occurs in populations/cryptic species. A recent molecular study ( 27 ) suggested that geographical separation is more important than fish host specificity in influencing OV genetic structure. Further studies should examine host selection for OV in Bithynia snails from different populations within each cryptic species, as they are the critical parasite amplifying stage.…”

Fish and Food-Fatale: Food-borne Trematode Opisthorchis viverrini and Cholangiocarcinoma

“…The limited variation that has been noted in a number of prior research also makes it crucial to emphasize that mitochondrial DNA appears to be inappropriate and untrustworthy for systematic and population genetic studies of O. viverrini ( Thaenkham et al ., 2010 ). Numerous research looking at genetic diversity and population structures have employed microsatellite DNA markers to bolster the idea that O. viverrini was a species complex ( Pitaksakulrat et al ., 2017 ; Namsanor et al ., 2020 ). In Bangkok, Thailand, most of the Opisthorchis viverrini s.l.…”