Survey of Rickettsia spp. and Orientia tsutsugamushi Pathogens Found in Animal Vectors (Ticks, Fleas, Chiggers) in Bangkaew District, Phatthalung Province, Thailand.

Rickettsial infections (Rickettsioses) are the causes of acute fever found in Thailand. It is classified as acute febrile illnesses transmitted by bloodsucking arthropod vectors (tick, flea, and chigger). This research investigated pathogens of scrub typhus in vectors from Bangkaew District, Phatthalung Province. A total of 303 pools of vector samples were ticks (Rhipicephalus sanguineus, R. microplus, and Haemaphysalis sp.), fleas (Ctenocephalides felis orientis, C. f. felis, and C. canis), and chiggers (Leptotrombidium deliense, Aschoschoengastia indica, Blankaartia acuscutellaris and Walchia disparunguis pingue) collected from reservoir hosts (dogs and rodents). The 17 and 56 kDa gene of Rickettsia causing scrub typhus were found in 29% of ticks and 98% of flea. DNA sequence analysis reveeled the detected strains were R. asembonensis and Rickettsia sp. cf1 and 5.The chiggers, 1%, were infected with Rickettsia strain TA763, a pathogen of scrub typhus.

Molecular diagnosis of cause of anisakiasis in humans, South Korea.

Anisakiasis in humans in South Korea has been considered to be caused exclusively by the larvae of Anisakis simplex sensu stricto and Pseudoterranova decipiens. Recently, however, DNA sequencing of larvae from 15 of 16 anisakiasis patients confirmed the cause to be Anisakis pegreffii infection. Molecular analysis should be performed for all extracted larvae.

Four cases of Taenia saginata infection with an analysis of COX1 gene.

Human taeniases had been not uncommon in the Republic of Korea (=Korea) until the 1980s. The prevalence decreased and a national survey in 2004 revealed no Taenia egg positive cases. However, a subsequent national survey in 2012 showed 0.04% (10 cases) prevalence of Taenia spp. eggs suggesting its resurgence in Korea. We recently encountered 4 cases of Taenia saginata infection who had symptoms of taeniasis that included discharge of proglottids. We obtained several proglottids from each case. Because the morphological features of T. saginata are almost indistinguishable from those of Taenia asiatica, molecular analyses using the PCR-RFLP and DNA sequencing of the cytochrome c oxidase subunit 1 (cox1) were performed to identify the species. The PCR-RFLP patterns of all of the 4 specimens were consistent with T. saginata, and the cox1 gene sequence showed 99.8-100% identity with that of T. saginata reported previously from Korea, Japan, China, and Cambodia. All of the 4 patients had the history of travel abroad but its relation with contracting taeniasis was unclear. Our findings may suggest resurgence of T. saginata infection among people in Korea.

Two new species of Rhabdochona (Nematoda: Rhabdochonidae) from freshwater fishes in Thailand.

Two new species ofrhabdochonid nematodes are described from the intestine of freshwater fishes in Chiang Mai Province, northern Thailand: Rhabdochona (Rhabdochona) pseudomysti sp. n. from the catfish Pseudomystus siamensis (Regan) (Bagridae, Siluriformes) in the Fang Brook, a tributary of the Kok River (the Mekong River basin), Fang District and Rhabdochona (Globochona) thaiensis sp. n. from the cyprinid Mystacoleucus marginatus (Valenciennes) (Cyprinidae, Cypriniformes) in the Ping River (the Chao Phraya River basin), Muang District. Rhabdochona pseudomysti is mainly characterized by simple, leaf-like oval deirids (a unique feature among Rhabdochona spp.), a prostom with 14 anterior teeth, the presence of basal prostomal teeth, the length ratio of the muscular and glandular portions of oesophagus (1:2.1-2.6), an unusually long left spicule (1.10-1.22 mm), length ratio of spicules (1:11.5-14.7), arrangement of genital papillae, and conspicuously elevated vulval lips. Rhabdochona thaiensis differs from other representatives of the subgenus Globochona Moravec, 1972 possessing caudal projections on the tail tip in that it has only 2 claw-shaped projections located ventrally on the tail tip of both males and females; the species is mainly characterized by the presence of distinct pseudolabia, 8 anterior prostomal teeth, absence of basal teeth, bifurcated deirids, length ratio of the muscular and glandular portions of oesophagus (1:11.3-11.9), conspicuously short (135-141 microm) left spicule, arrangement of genital papillae, and somewhat elevated vulval lips. Fully developed eggs of R. pseudomysti and R. thaiensis remain unknown. These are the first nominal species of Rhabdochona reported from Thailand.

Two new species of Cucullanus Müller, 1777 (Nematoda: Cucullanidae) from marine fishes off Thailand.

Based on light and scanning electron microscopical observations, two new species of Cucullanus Müller, 1777 (Nematoda: Cucullanidae) are described from the intestine of marine perciform fishes in the coastal region of the Gulf of Thailand, Thailand: Cucullanus rastrelligeri n. sp. from the short mackerel Rastrelliger brachysoma (Bleeker) (Scombridae) and Cucullanus thaiensis n. sp. from the brownstripe red snapper Lutjanus vitta (Quoy & Gaimard) (Lutjanidae). The former species, C. rastrelligeri, is mainly characterised by an elongate pseudobuccal capsule, the presence of a ventral sucker, markedly short spicules (306-360 µm), a median papilla-like formation on the anterior anal lip and a distinctly elevated posterior anal lip, the location of the deirids and excretory pore, and by the distribution of genital papillae in the male. The latter species, C. thaiensis, is characterised by a broad pseudobuccal capsule, the presence of a ventral sucker and spicules 680 µm long. It is morphologically closest to C. pargi González-Solís, Tuz-Paredez & Quintal-Loria, 2007, but differs from it mainly in the distribution of the genital papillae in the male and apparently larger gravid females, and, whereas C. thaiensis occurs in the West Pacific (Gulf of Thailand), C. pargi was described from the West Atlantic (Caribbean Sea). C. rastrelligeri and C. thaiensis are the first nominal species of cucullanid nematodes reported from marine fishes in Thai waters. Indocucullanus thapari Gupta & Srivastava, 1984 is transferred to Cucullanus as C. thapari (Gupta & Srivastava, 1984) n. comb.

Two nematode species from freshwater and marine fishes in Thailand, including Ascarophis scatophagi sp. nov. (Cystidicolidae) from Scatophagus argus (Scatophagidae).

One new and one known species of parasitic nematodes are reported from Thailand for the first time: Falcaustra kaverii (Karve et Naik,1951) (Kathlaniidae) from the intestine of the freshwater fish Poropuntius deauratus (Valenciennes) (Cyprinidae) (new host record) and Ascarophis scatophagi sp. nov. (Cystidicolidae) from the intestine of the marine fish Scatophagus argus (Linnaeus) (Scatophagidae). The morphology of both these species was studied with the use of light (LM) and scanning electron microscopy (SEM) (the latter method used for F. kaverii for the first time). The new species (A. scatophagi) is mainly characterized by nonfilamented, markedly elongate-oval eggs (size 42-45 × 18 µm), spicules 555-642 µm and 105-150 µm long, the muscular/glandular oesophagus length ratio (1:13-34), bifurcate deirids, the length of the female tail (159-249 µm) and cephalic structures typical of the nominotypical subgenus Ascarophis. Representatives of Falcaustra Lane, 1915 and Ascarophis van Beneden, 1871 were not previously reported from fishes in Thai waters.

A new record of Clinostomum philippinensis (Valasquez, 1959) in Trichogaster microlepis (Gunther, 1861) from Bung Borapet, Nakhon Sawan, Thailand.

Thirty-six freshwater fish from Bung Borapet, a large reservoir, were examined for helminths in July 2005. The prevalence of infection was 19.44 (7/36) and the intensity was 4.67 (168/36) per fish. Seven fish were infected with 4 species of helminths: 1 trematode, Clinostomum philippinensis (metacercariae); 1 cestode, Senga chiangmaiensis; 1 acanthocephalan, Pallisentis sp and 1 nematode, Camallanus anabantis. An encysted metacercaria of Clinostomum philippinensis was found in the gills of Trichogaster microlepis. The present study is a new report of Clinostomum metacercariae in the second intermediate host, T. microlepsis, in Thailand. Future work should investigate the epidemiology of the metacercarial stage in the intermediate host and the adult in the experimental definitive host.

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

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.