Molecular Phylogenetics of Centrocestus formosanus (Digenea: Heterophyidae) Originated from Freshwater Fish from Chiang Mai Province, Thailand

This study aimed to investigate the morphology and reconstruct the phylogenetic relationships of Centrocestus formosanus originating from 5 species of freshwater fish, i.e., Esomus metallicus, Puntius brevis, Anabas testudineus, Parambassis siamensis, and Carassius auratus, in Chiang Mai province, Thailand. Sequence-related amplified polymorphism (SRAP) and phylogeny based on internal transcribed spacer 2 (ITS2) and mitochondrial cytochrome c oxidase subunit 1 (CO1) were performed. The results showed similar morphologies of adult C. formosanus from day 5 after infection in chicks. C. formosanus originated from 4 species of freshwater fish had the same number of circumoral spines on the oral sucker, except for those from C. auratus which revealed 34 circumoral spines. The phylogenetic tree obtained from SRAP profile and the combination of ITS2 and CO1 sequence showed similar results that were correlated with the number of circumoral spines in adult worms. Genetic variability of C. formosanus also occurred in different species of freshwater fish hosts. However, more details of adult worm morphologies and more sensitive genetic markers are needed to confirm the species validity of C. formosanus with 34 circumoral spines originating from C. auratus in the future.

Prevalence of Centrocestus formosanus Metacercariae in Ornamental Fish from Chiang Mai, Thailand, with Molecular Approach Using ITS2

The prevalence of Centrocestus formosanus metacercariae was investigated in ornamental fish purchased from a pet shop in Chiang Mai, Thailand, including Carassius auratus (goldfish), Cyprinus carpio (Koi), Poecilia latipinna (Sailfin Molly), Danio rerio (Zebrafish), and Puntigrus tetrazona (Tiger barb). The parasite species was identified by the morphology of worms as well as by a molecular approach using ITS2. The results showed that 50 (33.3%) of 150 fish examined were infected with the metacercariae. The highest prevalence was found in C. auratus (83.3%), and the highest intensity was noted in C. carpio (70.8 metacercariae/fish). The most important morphological character was the presence of 32–34 circumoral spines on the oral sucker. The phylogenetic studies using the rRNA ITS2 region revealed that all the specimens of C. formosanus in this study were grouped together with C. formosanus in GenBank database. This is the first report on ornamental fish, C. carpio, P. latipinna, D. rerio, and P. tetrazona, taking the role of second intermediate hosts of C. formosanus in Thailand. Prevention and control of metacercarial infection in ornamental fish is urgently needed.

Prevalence of infection and molecular confirmation by using ITS-2 region of Fasciola gigantica found in domestic cattle from Chiang Mai province, Thailand

OBJECTIVE@#To investigate the infection of Fasciola gigantica (F. gigantica) in domestic cattle from Chiang Mai province and molecular confirmation using ITS-2 region.@*METHODS@#The liver and gall bladder of Bubalus bubalis (B. bubalis) and Bos taurus (B. taurus) from slaughterhouses were examined adult worms and prevalence investigation. The species confirmation with phylogenetic analysis using ITS-2 sequences was performed by maximum likelihood and UPGMA methods.@*RESULTS@#The total prevalences of infection in B. bubalis and Bubalus taurus (B. taurus) were 67.27% and 52.94% respectively. The respective prevalence in both B. bubalis and B. taurus were acquired from Doi-Saket, Muang, and Sanpatong districts, with 81.25%, 62.50% and 60.00% for B. bubalis and 62.50%, 50.00% and 47.06% for Bos taurus respectively. The species confirmation of F. gigantica and some related species by basing on maximum likelihood and UPGMA methods used, 4 groups of trematodes were generated, first F. gigantica group including specimen of Chiang Mai, second 2 samples of F. hepatica, third group of 3 rumen flukes; Orthocoelium streptocoelium, F. elongatus and Paramphistomum epliclitum and fourth group of 3 minute intestinal flukes; Haplorchis taichui, Stellantchasmu falcatus, Haplorchoides sp. and liver fluke; Opisthorchis viverrini respectively.@*CONCLUSIONS@#These results can be confirmed the Giant liver fluke which mainly caused fascioliasis in Chiang Mai was identified as F. gigantica and specimens were the same as those of F. gigantica recorded in other different countries. Nucleotide sequence of ITS-2 region has been proven as effective diagnostic tool for the identification of F. gigantica.

Potentially patoogenic free-living amoebae in sme flood-affected areas during 2011 chiang mai flood / Amebas potencialmente patogenicas de vida livre em algumas areas afetadas durante a inundacao de 2011 em Chiang Mai

SUMMARY The survey was carried out to investigate the presence of potentially pathogenic free-living amoebae (FLA) during flood in Chiang Mai, Thailand in 2011. From different crisis flood areas, seven water samples were collected and tested for the presence of amoebae using culture and molecular methods. By monoxenic culture, FLA were detected from all samples at 37 °C incubation. The FLA growing at 37 °C were morphologically identified as Acanthamoeba spp., Naegleria spp. and some unidentified amoebae. Only three samples (42.8%), defined as thermotolerant FLA, continued to grow at 42 °C. By molecular methods, two non-thermotolerant FlA were shown to have 99% identity to Acanthamoeba sp. and 98% identity to Hartmannella vermiformis while the two thermotolerant FLA were identified as Echinamoeba exundans (100% identity) and Hartmannella sp. (99% identity). This first report of the occurrence of FLA in water during the flood disaster will provide information to the public to be aware of potentially pathogenic FLA. .

RESUMO A pesquisa foi feita para investigar a presença de amebas de vida livre (FLA) durante a inundação em Chiang Mai, Tailândia, ano de 2011. A partir de diferentes áreas de inundação sete amostras de água foram coletadas e testadas para a presença de amebas usando métodos moleculares e de cultura. Através da cultura monoxênica, FLA foi detectada em todas as amostras após incubação a 37 °C. As FLA crescendo a 37 °C foram identificadas morfologicamente como Acanthamoeba spp, Naegleria spp e algumas amebas não determinadas. Somente três amostras (42,8%) definidas como FLA termotolerantes continuaram a crescer a 42 °C. Por métodos moleculares duas FLA termotolerantes tiveram 99% de identidade com a Acanthamoeba sp e 98% de identidade com Hartmannella vermiformis enquanto as duas FLA termotolerantes foram identificadas como Echinamoeba exundans (100% de identidade) e Hartmannella sp (99% de identidade). Este primeiro relato da ocorrência de FLA em águas durante inundações informa ao público que ele deve estar atento de FLA potencialmente patogênica. .

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

<p><b>OBJECTIVE</b>To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province, Thailand.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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%).</p><p><b>CONCLUSIONS</b>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.</p>

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.

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.