Theerakamol Pengsakul

• Ph.D.
• Professor (Associate) at Prince of Songkla University

Sand flies are potential carriers of various diseases that are transmittable to humans and animals. In this study, United States Centers for Disease Control light traps were set up in four tourist caves in the Thai provinces of Surat Thani, Nakhon Si Thammarat, Satun, and Chumphon to capture Idiophlebotomus asperulus sand flies. Over a period of th...

Background Sand flies, belonging to the Psychodidae family, represent small, hairy insects that serve as significant vectors in various important medical and veterinary diseases. Despite being recognized by the World Health Organization as an endemic area for leishmaniasis, Southeast Asia lacks comprehensive information on the species composition a...

Sand flies are small, hairy insects that play an important role as vector in many medical and veterinary diseases, Until recently, there is still a lack of informa tion on sand flies' diversity and sand fly-borne pathogen in Southeast Asia, despite the region's endemic Leishmaniasis status. This might lead to difficulties in disease control and pre...

Although ‘Candidatus Mycoplasma haematomacacae’ (formerly known as ‘Candidatus Mycoplasma haemomacaque’) have been reported on extensively in macaques from Thailand, the USA, Japan, and Brazil, their genetic characterization has primarily been restricted to the 16S rRNA sequences with no exploration on multi-locus sequence analysis. The primary goa...

Despite the natural occurrences of human infections by Plasmodium knowlesi, P. cynomolgi, P. inui, and P. fieldi in Thailand, investigating the prevalence and genetic diversity of the zoonotic simian malaria parasites in macaque populations has been limited to certain areas. To address this gap, a total of 560 long-tailed macaques (Macaca fascicula...

Hematological investigation is an essential tool for monitoring fish health. This objective of this research was to compare morphometric traits and blood cell characteristics between two representative pelagic fish species (Ambassis nalua and A. vachelli) and one benthic species (Inegocia japonica) collected from seagrass meadows off Libong Island...

This study aims to analyze the neutralization ability against Omicron parental variants in five clusters of individuals with different Coronavirus disease (COVID-19) immunity backgrounds, including individuals receiving a homologous or heterologous vaccine without prior infection, recovered patients with homologous or heterologous vaccination, and...

Reptile hematology provides important information to help assessment of health conditions and other reptile physiology and for biomarker discovery. The current hematology of snake from natural habitats of Thailand with morphological measurement is still rarely explored. In the present study, the extensive investigation on the morpho-metric analysis...

Recent focus on Culicoides species diversity in Thailand was prompted by a need to identify vectors responsible for the transmission of African Horse Sickness in that country. To assist rapid genetic identification of species, we sampled mitochondrial cytochrome c oxidase subunit I (COI) DNA barcodes (N = 78) from 40 species of Culicoides biting mi...

The appearance of eosinophilic granulocytes in the gastrointestinal tract of vertebrates often occurs as a physiologic response to chronic inflammation, but such information of Chrysopelea ornata (Shaw, 1802), as a common wild-snake in Thailand, probably remained unanswered. The current study aimed to describe the intestinal histology (PAS) stainin...

Simple Summary Phlebotomine sand flies (Diptera: Psychodidae) are hematophagous insects, and many species serve as vectors of various human and animal pathogens, including Leishmania and Trypanosoma protozoa. In Thailand, the first case of autochthonous leishmaniasis was reported 62 years ago. At present, the number of human cases is increasing in...

Over the years, cases of autochthonous leishmaniasis have been dramatically increasing in Thailand. Recently, several publications have claimed certain species of the phlebotomine sand flies and biting midges potentially serve as natural vectors of Leishmania and Trypanosoma species in this country. However, more information regarding the vector–pa...

The antigen rapid diagnostic test (Ag-RDT) is a useful diagnostic tool for the detection and management of COVID-19 spread. Global SARS-CoV-2 variant outbreaks have highlighted the need for a test capable of detecting SARS-CoV-2 variants with high sensitivity and a low limit of detection. This study aimed to develop and evaluate, both analytically...

Background Vaccines against the sexual stages of the malarial parasite Plasmodium falciparum are indispensable for controlling malaria and abrogating the spread of drug-resistant parasites. Pfs25, a surface antigen of the sexual stage of P. falciparum , is a leading candidate for transmission-blocking vaccine development. While clinical trials have...

This study examined the abundance of various immature mosquito species and ascertained selected environmental conditions in the pitcher. A total of hundred pitchers (Nepenthes mirabilis var. mirabilis), including 50 upper pitchers and 50 lower pitchers, were collected during rainy and dry seasons from Songkhla Province, Thailand. A total of 546 mos...

Chikungunya virus (CHIKV) is primarily transmitted by Aedes mosquitoes and is responsible for reemerging disease internationally. Container habitats of immature Aedes mosquitoes are often found around residential areas, thus water-holding container investigation is an important vector control strategy. This study aimed to survey mosquito species in...

Background: Vaccines against the sexual stages of the malarial parasite Plasmodium falciparum are indispensable for controlling malaria and abrogating the spread of drug-resistant parasites. Pfs25, a surface antigen of the sexual stage of P. falciparum, is a leading candidate for transmission-blocking vaccine development. While clinical trials have...

Infection by the mosquito-borne chikungunya virus (CHIKV) causes acute febrile illness and debilitating arthralgia. Outbreaks are sometimes not recognized because of its clinical resemblance to the more common dengue fever ubiquitous in tropical countries. An upsurge of dengue-like illness was reported in Satun province located in southern Thailand...

Recently, mosquito-borne diseases have been a significant problem for public health worldwide. These diseases include dengue, ZIKA and malaria. Reducing disease spread stimulates researchers to develop automatic methods beyond traditional surveillance Well-known Deep Convolutional Neural Network, YOLO v3 algorithm, was applied to classify mosquito...

Space spraying is a common vector control measure used to suppress Aedes aegypti mosquito populations during outbreaks of vector-borne diseases such as dengue. Space spraying can be conducted inside or outside the household or both. The current study assessed the effectiveness of space-spraying in reducing vector populations in an active endemic se...

Knowledge of the reproductive biology of the toadfish is still limited. The present study therefore aimed to provide basic knowledge about ovarian histology in the mangrove toadfish Batrachomoeus trispinosus, a potential aquaculture species in Thailand. To this end, we performed histological analysis of the ovaries (n = 20, all females, total lengt...

Thirty-five white-spotted geckos, Tarentola annularis were collected from Shendi area, River Nile State,Sudan, between June and September 2019 and examined for the presence of haemoparasites infection. Six (17.14%)geckos were found to be positive for intra erythrocytic haemogregarine (Apicomplexa: Haemogregarinidae) specieswith a mean overall infec...

Microscopic observation of mosquito species, which is the basis of morphological identification, is a time-consuming and challenging process, particularly owing to the different skills and experience of public health personnel. We present deep learning models based on the well-known you-only-look-once (YOLO) algorithm. This model can be used to sim...

Cutaneous myiasis is an infestation of the skin by fly larvae, which usually occurs in adults. We present a case of cutaneous myiasis caused by Chrysomya megacephala in a 3-month-old infant with psoriasis vulgaris. In this case report, we highlight the clinical, histopathologic, taxo-nomic identification, and treatment of cutaneous myiasis occurrin...

The Anopheles dirus mosquito is a primary malaria vector that transmits many species of Plasmodium parasites in Thailand and is widely spread across its geographic area. In the current study, the levels of expression of the suppressor of cytokine signaling (SOCS) gene in An. dirus mosquitoes infected with P. vivax were examined. The level of the ge...

The gonadal structure of insects has been well reported but there is a lack of such information from tortoise beetles that are an economically important insect. In this study, the gonadal structure and differentiating stage of gametogenesis of tortoise beetles Aspidomorpha sanctaecrucis are examined using the histological technique. At the level of...

The Arius maculatus is one of the most economically important estuarine fish and a potentially viable estuarine fish for aquaculture in Thailand. However, an adequate understanding of its reproductive biology, in order to support the aquacultural development and fisheries management of this fish, is currently lacking. The goal of this study was to...

The microanatomical structure of mucous secreting cells (Ms) in fish has been widely found; however, there is a lack of research on the Schaap’s dragonet, Callionymus schaapii, which is regarded as an important benthic fish. The identification and distribution of Ms in different areas along the integumentary system of Callionymus schaapii were ther...

The histological information a digestive system has never been reported in the Hemiraphids. Here, we first observed a basic histology of digestive system of Dermogenys pusilla, as a representative hemiramphid fish from Family Hemiramphidae. All specimens (n = 20) were collected on October 2016 from Estuary Pranburi River, Thailand. The structural e...

The development of viviparity, live-bearing, is an ill-defined evolutionary event that is considered to have emerged in several lineages of reptiles. Therefore, the knowledge from a wide variety of viviparous species will offer better insight into understanding the reproductive adaptations associated with the development of viviparity. The dog-face...

This study investigated the ectoparasites of the Nile Rat, Arvicanthis niloticus in Shendi area, River Nile State, Sudan. Eighty nine A. niloticus were collected for the first time from the horticultural fields of Shendi, between January to June 2018, and their entire fur was combed thoroughly, using a fine-tooth comb. Any removed ectoparasites wer...

Objective: To demonstrate the effect of indoor spraying and window screens on Aedes aegypti mosquito density after space spraying. Methods: A total of 141 households (the study houses) in six communities of Songkhla City, located in Songkhla Province of southern Thailand, were randomly selected and the adult Ae. aegypti populations were assessed pr...

Three hundred and sixty fecal samples of stray dogs were collected between July and December 2018, from open grounds of Shendi city and two suburbs (Gulia and Musiab), River Nile State, Sudan, and were examined for helminthic infections. The results showed 43 (11.9%) of the samples were positive for at least one species of helminth. A total of four...

Objective: To determine the morphological characteristics of variations in populations of female adult sand fly, Sergentomyia anodontis Quate and Fairchild, 1961 in caves in southern Thailand using morphometric analysis. Methods: A total of 107 female Sergentomyia anodontis were isolated from 651 sand flies captured by CDC light traps overnight in...

Eighty nine rats, Arvicanthis niloticus, were collected from the horticultural fields of Shendi area in Sudan, between January and June 2018, and examined for the first time for helminth parasites. Thirty seven (41.6%) of the collected rats were infected, with an overall mean intensity of 4.4 helminths per a rat. A total of 6 helminth species were...

The spotted bent-toed gecko Cyrtodactylus peguensis is one of the exploited reptiles in Thailand. In order to provide basic information for the digestive system of this species, we have examined histologically the gastrointestinal and accessory organs of C. peguensis using routine methods. The gastrointestinal region of this reptile started from th...

Phlebotomine sand flies are tiny, hairy, blood-sucking nematoceran insects that feed on a wide range of hosts. They are known as a principal vector of parasites, responsible for human and animal leishmaniasis worldwide. In Thailand, human autochthonous leishmaniasis and trypanosomiasis have been reported. However, information on the vectors for Lei...

In order to increase knowledge on the reproductive biology of Hemiramphus far as the most economical marine fish, the gonadal structure and gametogenic differentiation of this fish were clearly described by visual observation and histological technique. Based on the visual observation in female fish, the typical morphology of the mature ovary was a...

Hematological profiles have been extensively used as a biomarker of fish, but such information is still limited for juvenile fish in mangrove forests of Thailand. The current study aimed to investigate the morphological characteristics of blood cells in five ecologically important estuarine fish species from the Estuary Pranburi River (EPR), Thaila...

This is the first report on helminths parasitize the white-spotted wall gecko, Tarentola annularis from Shendi area in Sudan. A total of 32 geckos were collected between January and May 2018, and examined for helminth infections. Three nematode species of the family Pharyngodonidae were identified: Pharyngodon mamillatus, Spauligodon brevibursata a...

A new coelozoic myxozoan species, Ceratomyxa batam n. sp., was identified in cultured carangid fish, Trachinotus ovatus (Perciformes: Carangidae), in waters off Batam Island of Indonesia. The bi- and trivalved spores were observed in the gallbladder of T. ovatus. Mature bivalved spores of C. batam n. sp. were transversely elongated and narrowly cre...

Schistosomiasis intermediate-hosts, snails, are usually surface dwellers of different type of freshwater bodies and their geographical distribution and population dynamics may be influenced by many factors such as temperature, oxygen dissolved in water, flooding and desiccation. In this study, we interested in temperture, rainfall, light, turbidity...

A plurality of investigations on the heart structure of reptiles has been extensively reported; however, it has yet to conduct studies in Cerberus rynchops, the so-called common estuarine water-snake. In this current study, we histologically started to examine the heart wall of the atrium, ventricle chambers, and study the existence of the blood ce...

This is the first study which explained the histopathology in kidney and liver of the captive broodstock ( Rastrelliger brachy - soma ) during its juvenile stage, to assess the health status. All fishes (n = 24) with a mean of 5.02±0.87 (SD) cm in total length, were collected during October to December 2013 and processed using standard histologica...

Observation of the esophagogastric region and liver tissue of the dog-faced water snake, Cerberus rynchops, living in Thailand was evaluated using standard histological techniques. The results revealed that the digestive tract of this snake consists of three parts: the oesophagus, stomach and intestine, respectively. From the histological analysis,...

Culicine mosquitoes are medically important vectors. Therefore, mosquito control measures are a crucial strategy to interrupt disease transmission. Collection of data on mosquito feeding patterns is crucial for developing an effective vector control strategy. The objective of this study was to use molecular biology methods to identify the sources o...

The tea green leafhopper, Empoasca vitis Göthe, is one of the most serious pests in tea growing areas. This study investigated the roles played by olfaction and vision in host orientation behavior. The compound eye of E. vitis was found to be a photopic eye; few olfactory sensilla were found on the antennae, while abundant gustatory sensilla were r...

Background: Schistosomiasis is a debilitating disease, infects millions of people in tropical and subtropical regions. This study assessed the situation of the urinary schistosomiasis among schoolchildren of the Alsaial Alsagair village, Sudan. Methods: A cross-sectional survey was carried out in 2016, in the Alsaial Alsagair village, and 385 sampl...

Objective: To evaluate the situation regarding gastrointestinal helminth parasites in ruminants (cattle, sheep and goats) slaughtered in the abattoir of Shendi, River Nile State, Sudan. Methods: From September 2015 to October 2016, a total of 687 fecal samples were collected and analyzed by flotation and sedimentation techniques. Results: A total o...

Short mackerel, Rastrelliger brachysoma (Bleeker, 1851), is an economically important marine fish in the Gulf of Thailand that is potentially threatened by anthropogenic factors. Fifty specimens were obtained between October 2013 to February 2014 from wild populations, p rocessed using standard histological techniques and stained with Harris’s...

Schistosomiasis is the most prevalent parasitic disease after malaria in terms of socioeconomic and public health importance in the developing world. In Sudan, since the year 1919, the disease has been discovered in the northern part of the country, and later it was reported from different parts including Eastern and Western Sudan, Lake Nasser area...

Although female sand flies are best known as the vectors of Leishmania parasites and viruses, several previous reports have demonstrated that these insects can also act as vectors for the trypanosomes of bats, lizards, and snakes. In this report, we created an inventory of Phlebotomine sand flies from southern Thailand. A novel trypanosome was foun...

We analyzed the dietary composition of 153 specimens of the subdesert toad, Amietophrynus xeros, collected in the rainy and dry seasons in Shendi, Sudan. The dietary items in the toads included a wide variety of arthropod prey belonging to 10 orders: Hymenoptera, Coleoptera, Heteroptera, Diptera, Isoptera, Lepidoptera, Orthoptera, Acari, Araneae, a...

This study was conducted to determine the role of some micro-ecological factors influencing the population dynamics of schistosomiasis intermediate host snails in the water bodies of Khartoum State, Sudan. The results show that the air and water temperature play a significant role in the determination of snail growth, a gradual increase of air and...

This study was conducted to determine the role of some micro-ecological factors influencing the population dynamics of schistosomiasis intermediate host snails in the water bodies of Khartoum State, Sudan. The results show that the air and water temperature play a significant role in the determination of snail growth, a gradual increase of air and...

The objective of the present study was to evaluate the efficacy of five different diagnostic techniques (haematouria, macro-haematouria, syringe filtration, vacuum flask filtration and sedimentation) in the detection of urinary schistosomiasis. Likewise, five techniques (direct smear, cellophane thick smear, ether-formalin, modified Kato-template a...

The objective of the present study was to evaluate the efficacy of five different diagnostic techniques (haematouria, macro-haematouria, syringe filtration, vacuum flask filtration and sedimentation) in the detection of urinary schistosomiasis. Likewise, five techniques (direct smear, cellophane thick smear, ether-formalin, modified Kato-template a...

The present study was conducted from July to December 2015 and found that the Shendi area, River Nile State, Sudan, Africa, hosts considerable bird diversity with 35 species being observed belonging to 22 families; of which Columbidae, Meropidae and Nectariniidae were the most frequently observed species.

The present study was conducted from July to December 2015 and found that the Shendi area, River Nile State, Sudan, Africa, hosts considerable bird diversity with 35 species being observed belonging to 22 families; of which Columbidae, Meropidae and Nectariniidae were the most frequently observed species.

This study aims to demonstrate a spatial clustering approach for identifying risk households of dengue virus infection during the period of insecticide spraying-ultra low volume (ULV). All households located within 100 m radius of spraying area were recorded with geographic coordinates and divide into three groups of spraying (unsprayed, only outdo...

Background: Schistosomiasis is one of the major communicable diseases of public health and socioeconomic importance in developing countries. This study assessed the situation of schistosomiasis among villagers of the New Halfa Agricultural Scheme, Sudan. Methods: An epidemiological survey was carried out in three randomly selected residential si...

The fish Gambusia affinis (Baird and Girard, 1853) was used under laboratory conditions to evaluate its efficacy as a predator against different stages of the snail, Biomphalaria pfeifferi, the intermediate host of human Schistosoma mansoni. Results showed that G. affinis was a voracious predator towards egg-masses and neonate snails with a shell d...

Sixty-nine subdesert toads, Amietophrynus (Bufo) xeros, were collected in Shendi, Sudan, from August to November 2014, and examined for the first time for the presence of internal helminth parasites. Sixty-seven (97.1%) of the toads were found infected with one or more helminth species including, four Nematoda: Aplectana macintoshii, Rhabdias bu...

Sixty-nine subdesert toads, Amietophrynus (Bufo) xeros, were collected in Shendi, Sudan, from August to November 2014, and examined for the first time for the presence of internal helminth parasites. Sixty-seven (97.1%) of the toads were found infected with one or more helminth species including, four Nematoda: Aplectana macintoshii, Rhabdias bufon...

Objective: To investigate the predation efficacy of the freshwater leech, Limnatis nilotica (L. nilotica) as a potential biological control agent against different stages of the Bulinus truncatus (B. truncatus), the intermediate host of human Schistosoma haematobium, under laboratory conditions. Methods: The leech L. nilotica and the snail B. trunc...

Genitourinary amoebiasis is a rare form of kidney and urinary tract infection caused by Entamoeba histolytica. Here, we describe the first case of unusual infection caused by E. histolytica in Bueng Kan province, northeast, Thailand. A 63-year-old female patient was diagnosed as acute pyelonephritis. E. histotolytica trophozoites were accidentally...

Objective: To examine the resurgence rate, house density index (HDI) and parous rate of the Aedes aegypti vector after space spraying carried out by the routine spraying team, and compare with the rates after standard indoor ultra low volume (SID-ULV) spraying carried out by the trained research spraying team. Methods: Between March and September 2...

Background Dengue is commonly found in the tropical and subtropical regions. The disease is still affecting the population of the world especially in Southeast Asia. The current increase in both morbidity and mortality rates was associated with the potentiality of the viral transmission. Surveillance focusing on the virus infection in principal den...

Biological studies on dengue vectors, Aedes aegypti and Ae. albopictus and prevalence of dengue viruses found in both species were carried out in 25 provinces of Thailand. Both vectors were usually found in all provinces; however, Ae. aegypti and Ae. albopictus could be found up to 1,509 and 1,928 meters above sea level, respectively. It was found...

Larvae of the fox tapeworm, Echinococcus multilocularis, cause alveolar echinococcosis (AE), which is considered to be the most lethal helminthic infection in humans. Since it develops in host organs, the parasite must have evolved a stress defense system to cope with various genotoxic and cellular stresses that may cause DNA damage and genomic ins...

Head louse infestation, which is caused by Pediculus humanus capitis, occurs throughout the world. With the advent of molecular techniques, head lice have been classified into three clades. Recent reports have demonstrated that pathogenic organisms could be found in head lice. Head lice and their pathogenic bacteria in Thailand have never been inve...

An olfactory co-receptor gene AalbOrco was isolated and described from Aedes albopictus using the RACE technique. AalbOrco contained typical structures of seven transmembrane domains and Nin-Cout. Sequence analysis demonstrated that AalbOrco is very similar to Orco orthologs from other dipterans, especially in the C-terminus. AalbOrco was expressed...

The geckos are common reptile of houses belonging to the family Gekkonidae; they distributed across all tropical and subtropical regions, and are well known to be carriers of different parasite species. This study investigated the gastrointestinal parasites fauna of the fan-toed gecko, Ptyodactylus ragazzi in Shendi, Sudan. A total of 37 P. ragazzi...

Life cycle of the trematode worm, Exorchis mupingensis, includes Oncomelania hupensis snail as first intermediate host and several small freshwater fishes as second intermediate hosts, while the carnivorous fish, Parasilurus asotus, serves as a final host of this parasite. P. asotus fish, Labidochromis caeruleus fish and E. mupingensis cercariae we...

Apyrase encoding metal-ions activated plasma membrane protease is present in animal and plant tissues. This enzyme can hydrolyze ADP and ATP pyrophosphate bond, resulting in AMP and free phosphate groups, and plays an important role for insects and parasites to evade host immune system. However localization and function of apyrase in the canine hoo...

Information concerning morphological and functional basis of defense cells of Oncomelania hupensis (Gastropoda: Pomatiopsidae), intermediate host of schistosomiasis parasite, Schistosoma japonicum, observed through optical microscopy (light and fluorescence); scanning electron microscopy (SEM); and transmission electron microscopy (TEM) is presente...

Procambarus clarkii crayfish was evaluated as a potential biological control agent against Oncomelania hupensis snail, the intermediate host of Schistosoma japonicum. Both sexes of the crayfish of different sizes were allowed to feed upon three different snail lengths: < 5 mm; 5-7 mm; and > 7 mm, in the laboratory, and outdoors in simulated semi-fi...