Chalobol Wongsawad

Co-infection with Opisthorchis viverrini and Haplorchis taichui detected by human fecal examination in Chomtong district, Chiang Mai Province, Thailand.

Diseases caused by the liver fluke, Opisthorchis viverrini and the minute intestinal fluke, Haplorchis taichui, are clinically important, especially in the Northeast and North regions of Thailand. It is often difficult to distinguish between these trematode species using morphological methods due to the similarity of their eggs and larval stages both in mixed and co-infections. A sensitive, accurate, and specific detection method of these flukes is required for an effective epidemiological control program. This study aimed to determine the prevalence of O. viverrini and H. taichui infections in human feces by using formalin-ether sedimentation and high annealing temperature random amplified polymorphic DNA (HAT-RAPD) PCR methods. Fecal specimens of people living along the Mae Ping River, Chomtong district were examined seasonally for trematode eggs using a compound microscope. Positive cases were analyzed in HAT-RAPD, DNA profiles were compared with adult stages to determine the actual species infected, and specific DNA markers of each fluke were also screened. Our results showed that out of 316 specimens, 62 were positive for fluke eggs which were pre-identified as O. viverrini and H. taichui. In addition, co-infection among these two fluke species was observed from only two specimens. The prevalence of H. taichui infections peaked in the hot-dry (19.62%), gradually decreased in the rainy (18.18%), and cool-dry seasons (14.54%), respectively. O. viverrini was found only in the hot-dry season (6.54%). For molecular studies, 5 arbitrary primers (Operon Technologies, USA) were individually performed in HAT-RAPD-PCR for the generation of polymorphic DNA profiles. The DNA profiles in all 62 positives cases were the same as those of the adult stage which confirmed our identifications. This study demonstrates the mixed infection of O. viverrini and H. taichui and confirms the extended distribution of O. viverrini in Northern Thailand.

Prevalence of Haplorchis taichui and Haplorchoides sp. Metacercariae in Freshwater Fish from Water Reservoirs, Chiang Mai, Thailand

A parasitological investigation on trematode metacercariae was made on 62 freshwater fishes of 13 species in northern Thailand; Cyclocheilichthys apogon, Puntioplites proctozysron, Labiobarbus siamensis, Barbodes gonionotus, Barbodes altus, Henicorhynchus siamensis, Osteochilus hasselti, Notopterus notopterus, Mystacoleucus marginatus, Anabas testudineus, Systomus orphoides, Morulius chrysophykadian, and Hampala macrolepidota. The fish were caught over the summer period (February-May 2007) from 2 Chiang Mai water reservoirs, i.e., the Mae Ngad (UTM 47Q E 503200, 47Q N 2119300) and the Mae Kuang Udomtara (UTM 47Q E 513000, 47Q N 2092600) Reservoirs in Chiang Mai province, Thailand. The prevalence of heterophyid (Haplorchis taichui and Haplorchoides sp.) metacercariae in these fish was 83.9% and 74.2% in the Mae Ngad and Mae Kuang Udomtara Reservoirs, respectively. The highest intensity of heterophyid metacercariae in H. siamensis in the Mae Ngad was 120.4 and that in P. proctozysron in the Mae Kuang Udomtara was 180.0. The fish, A. testudineus, C. apogon, and M. chrysophykadian, were not found to be infected with H. taichui metacercariae. The results show that the freshwater fish in Chiang Mai water reservoirs are heavily infected with H. taichui and Haplorchoides sp. metacercariae.

Ethnomedicinal plants used for digestive system disorders by the Karen of northern Thailand

BackgroundDigestive system disorders have a substantial effect on worldwide morbidity and mortality rates, including in Thailand, where the majority of the rural areas have a lack of proper sanitation and awareness about disease prevention. This has led to the prevalence of different types of digestive diseases. Karen people in Thailand still use medicinal plants as first aid remedies in treating these diseases. Therefore, this study aimed at documenting the plants used to cure and prevent different types of digestive system disorders by Karen people of Chiang Mai Province, northern Thailand.MethodsEthnomedicinal data were collected from six key informants and 172 non-specialist informants regarding their traditional knowledge of medicinal plants. Quantitative approaches were used to determine Use Value (UV), Informant Consensus Factor (ICF) and Fidelity Level (FL) values.ResultsThe study revealed that 36 medicinal plant species belonging to 31 genera and 24 families were used to treat digestive system disorders. The most prevalent plant families were Zingiberaceae (6 species), Euphorbiaceae (4 species) and Fabaceae (4 species). Leaves were the most commonly used plant part accounting for 32.6% of the plants, followed by the bark (18.6%). About 60% of the administrations were given orally by potion (60%) and consumption as food was also indicated (14%). The highest ICF values were recorded for carminative disorders, stomachaches, geographic tongue, constipation, appetite stimulants and food poisoning (1.00 each) indicating the best agreement among the informants knowledge of medicinal plants that were used to treat aliments in these categories. The highest fidelity level values were recorded for Punica granatum (100.00), Psidium guajava (95.45), and Gymnopetalum integrifolium (90.91) showing conformity of knowledge on species with the best healing potential.ConclusionMedicinal plants still play an important role among Karen culture. The present information on these medicinal plants, which have high UV and FL values, may serve as the baseline data to initiate further research for the discovery of new compounds and the biological activities of these potential plant remedies. Further research on these plants may provide some important clues for the development of new drugs for the treatment of digestive system diseases.

Traditional knowledge on medicinal plant of the Karen in northern Thailand: A comparative study

ETHNOPHARMACOLOGICAL RELEVANCE We studied traditional medicinal plant knowledge among the Karen in northern Thailand. AIM OF THE STUDY To compare traditional medicinal knowledge in 14 Karen villages in northern Thailand and determine culturally important medicinal plant species in each Karen village. MATERIALS AND METHODS We interviewed 14 key informants and 438 non-specialist informants about their traditional knowledge of medicinal plants. We tested normality of the data and correlations with distance to the nearest city using Kolmogorov-Smirnov tests and Spearmans rank correlation coefficient. Cluster analysis and cultural importance index (CI) were calculated for the similarity of medicinal plant used and culturally importance medicinal plant species among Karen villages respectively. RESULTS In total 379 medicinal plant species were used. Number of medicinal plants used positively correlate with distance to the nearest city. Relatively low similarities of medicinal plant species and different CI values for species among the different areas were found. CONCLUSIONS Traditional medicinal plants still play an important role in medicinal practice of the Karen. Local environments, availability of medicinal plant and distance between Karen villages and the nearest city affect the amount of traditional medicinal knowledge in each Karen village. The medicinal plants in this study with high CI values might give some useful leads for further biomedical research.

Epidemiology of cercarial stage of trematodes in freshwater snails from Chiang Mai province, Thailand.

OBJECTIVE To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province, Thailand. METHODS The snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012. The prevalence of cercarial infection in snails was investigated using the crushing method. The drawing was done with the help of a camera lucida for the morphological study. RESULTS A total of 2 479 snail individuals were collected and classified into 7 families, 11 genera, and 14 species, Among them, 8 snails species were found to be infected with an overall prevalence of 17.27% (428/2 479), which infected with nine groups of cercariae; gymnocephalous cercaria, strigea cercaria, megalurous cercaria, monostome cercaria, parapleurolophocercous cercaria (Haplorchis cercaria), pleurolophocercous cercaria, furcocercous cercaria (Transversotrema cercaria), xiphidiocercaria, and virgulate cercaria. The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails (64.25%). CONCLUSIONS The various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals. This work will provide new information on both the distribution and first intermediate host of trematodes.

Molecular Markers for Identification of Stellantchasmus falcatus and a Phylogenic Study using the HAT-RAPD Method

Stellantchasmus falcatus is a minute intestinal fluke in the family Heterophyidae. Metacercariae, the infective stage, were reported in a marine fish, mullet Liza subviridis, and a fresh water fish, Dermogenus pusillus, in Thailand. Adults were found in chicks, rats, cats, and humans. Morphological studies were done for comparing Stellantchasmus sp. worms found in 2 different fish hosts; their shapes and organ arrangements were very similar except for the prepharynx length. Therefore, the present study aimed to compare their DNA fingerprints using the HAT-RAPD method for both types of Stellantchasmus and several other related species. Ten arbitrarily selected primers (OPA-04, OPA-09, OPN-02, OPN-03, OPN-09, OPN-12, OPP-11, OPR-15, OPX-13, and OPAD-01) were used. It was found that OPA-09, OPN-03, and OPAD-01 were able to generate S. falcatus specific fragments in mullets which consisted of 200, 760, and 280 bp, respectively. In addition, the results of morphologic, DNA fingerprinting, and phylogenetic analyses strongly suggest that the fresh water and marine specimens of Stellantchamus may be different species.

Echinostoma revolutum: freshwater snails as the second intermediate hosts in Chiang Mai, Thailand.

The occurrence of 37-collar spined echinostome metacercariae in freshwater snails was investigated in 6 districts of Chiang Mai Province, Thailand, from October 2011 to April 2012. A total of 2,914 snails that belong to 12 species were examined, and 7 snail species (Clea helena, Eyriesia eyriesi, Bithynia funiculata, Bithynia siamensis siamensis, Filopaludina doliaris, Filopaludina sumatrensis polygramma, and Filopaludina martensi martensi) were found infected with echinostome metacercariae. The prevalence of metacercariae was the highest in Filopaludina spp. (38.5-58.7%) followed by B. funiculata (44.0%), E. eyriesi (12.5%), B. siamensis siamensis (8.2%), and C. helena (5.1%). Metacercariae were experimentally fed to hamsters and domestic chicks, and adult flukes were recovered from both hosts at days 15 and 20 post-infection. The adult flukes were identified based on morphological features, morphometrics, host-parasite relationships, and geographical distribution. They were compatible to Echinostoma revolutum or Echinostoma jurini, with only minor differences. As the adults were recovered from both hamsters and chicks, our specimens were more compatible to E. revolutum rather than E. jurini (reported only from mammals). This is the first report for metacercariae of E. revolutum in the snail host, C. helena, and also confirmed that Filopaludina spp., E. eryresi, and Bithynia spp. act as the second intermediate hosts of E. revolutum under natural conditions, which are indigenously distributed in Chiang Mai province.

Two new sibling species of Procamallanus (Spirocamallanus) (Nematoda: Camallanidae) from marine fishes in the Gulf of Thailand.

abstract:  Based on light and scanning electron microscopical examinations, 2 new morphologically similar species of the subgenus Procamallanus (Spirocamallanus) (Nematoda: Camallanidae) possessing 2 caudal spikes are described from the intestine of marine perciform fishes from the Gulf of Thailand off the Thai coast, i.e., Procamallanus (S.) rigbyi n. sp. from Otolithes ruber (Bloch and Schneider) (Sciaenidae) and Procamallanus (S.) similis n. sp. from Sillago sihama (Forsskål) (Sillaginidae). The former species is mainly characterized by the presence of 13–14 spiral ridges in the buccal capsule, location of deirids at about mid-way between the buccal capsule and the nerve ring, and by the length of the right spicule (315–360 µm), whereas the latter is characterized by 10–12 spiral ridges, deirids situated at short distance posterior to the buccal capsule, and the right spicule 435–492 µm long. Because of their inadequate descriptions, most species of this subgenus reported from marine fishes of the Indo-Pacific region are considered species inquirendae. Spirocotyle Yasmin and Bilqees, 2007 is considered a junior synonym of Procamallanus Baylis, 1923. Since Procamallanus (S.) otolithi Ashraf, Farooq and Khanum, 1977, P. (S.) otolithi (Gupta and Garg, 1986) and P. (S.) otolithi (Yasmin and Bilqees, 2007) are junior homonyms to P. (S.) otolithi Bilqees and Kazmi, 1974, they are renamed Procamallanus (S.) pakistanensis n. nom., Procamallanus (S.) problematicus n. nom., and Procamallanus (S.) incognitus n. nom., respectively (all species inquirendae). Procamallanus rigbyi and P. similis are the first nominal species of this genus reported from marine fishes off the coast of Thailand.

Developmental and Phylogenetic Characteristics of Stellantchasmus falcatus (Trematoda: Heterophyidae) from Thailand

This study aimed to investigate the infection status, worm development, and phylogenetic characteristics of the intestinal trematode, Stellantchasmus falcatus. The metacercariae of S. falcatus were detected only in the half-beak (Dermogenus pusillus) out of the 4 fish species examined. Their prevalence was 90.0%, and the intensity of infection was 919 metacercariae on average. Worms were recovered from 33 (97.1%) of 34 chicks that were experimentally infected with 200 S. falcatus metacercariae each, and the average recovery rate was 43.0%. The body size and inner organs of S. falcatus quickly increased in the experimental chicks over days 1-2 post-infection (PI). In addition, ITS2 sequence data of this parasite were analyzed to examine the phylogenetic relationships with other trematodes using the UPGMA method. The results indicated that the ITS2 sequence data recorded from trematodes in the family Heterophyidae appeared to be monophyletic. This study concluded that D. pusillus serves as a compatible second intermediate host of S. falcatus in Thailand and that S. falcatus can develop rapidly in the experimental chicks. Data collected from this study can help to close the gap in knowledge regarding the epidemiology, biology, and phylogenetic characteristics of S. falcatus in Thailand.

Molecular phylogeny of trematodes in Family Heterophyidae based on mitochondrial cytochrome c oxidase subunit I (mCOI).

OBJECTIVE To analyze a phylogenetic tree for understanding the molecular systematic of trematode in Family Heterophyidae, which are highly distributed in Thailand. METHODS Based on thirteen sequences of mitochondrial cytochrome c oxidase subunit I (mCOI) gene from six genera of heterophyid trematodes, viz. Haplorchis, Stellantchasmus, Centrocestus, Metagonimus, Pygidopsis, and Haplorchoides were aligned automatically using the Clustal × 2.0 program. A phylogenetic tree was constructed by maximum likeinghood (ML) and neighbor-joining (NJ) methods, with 1 000 bootstrap using the 5.0 program. RESULTS The phylogenetic relationship from both methods was similar and separated into three groups consisting of Haplorchoides pumilio group, Haplorchoides taichui group and another heterophyid genera. CONCLUSIONS The sequence data of mtCOI can be used to investigate the phylogenetic relationships of trematodes at the genus level. Each clade of different genera of heterophyid trematodes can be separated into sister groups that correlated with the morphological characteristic, kind of secondary intermediate host and geographic distribution.