Eastern Thailand Research Articles

Microplastic occurrence in surface sediments from coastal mangroves in Eastern Thailand: Abundance, characteristics, and ecological risk implications

Mangroves have emerged as one of the ecosystems facing severe threats from microplastic pollution originating from both terrestrial and marine sources. The contamination of mangrove sediment has become a widespread concern, with limited global data on this issue. In this study, surface mangrove sediments (at a depth of 0–5 cm) were collected from six representative mangroves in eastern Thailand to assess microplastic abundance, distribution, and characteristics and conduct an ecological risk assessment. The results revealed that the microplastic concentration in all mangrove sediments had an average abundance of 2213.33 ± 1787.74 items/kg of dry weight. The higher microplastic concentration observed in the Mueang Rayong mangrove (MR) and Laem Chabang mangrove (LB) was primarily attributed to sewage discharge from municipal and industrial areas. These microplastics were predominantly fibers and fragments, measuring less than 1 mm, and exhibited blue and transparent-white colors. They were primarily composed of polypropylene (PP) and polyethylene (PE), accounting for a significant proportion of all mangrove sites. Assessing the pollution load index (PLI) and ecological risk index (RI), the PLI indicated a hazard level I. At the same time, microplastics posed varying degrees of ecological risk (RI) to all studied mangroves, ranging from high (hazard level III) to extreme danger (hazard level V). Microplastics were found to pose ecological risks within these mangroves, with the LB mangrove showing the highest level of risk.

Preliminary investigation of microplastic contamination in river snails (Filopaludina martensi) in Eastern Thailand and evaluation of human exposure

Microplastic contamination in the aquatic environment is a growing environmental issue with implications for food safety concerns. This study investigated microplastics in river snails (Filopaludina martensi) obtained from local markets in the eastern province of Thailand. The study analyzed the abundance, shape, size, color, and polymer type of microplastics extracted from river snail tissue and estimated human intake of microplastics through river snail consumption. The results revealed that the average microplastic abundance was 88.63 ± 51.18 particles/g wet weight. The predominant microplastics were fibers and fragments smaller than 1.0 mm, with colors ranging from transparent-white. Polymer analysis indicated that river snails primarily contained polyethylene (PE), polypropylene (PP), and polystyrene (PS). Microplastics’ estimated annual intake (EAI) was significantly higher than the average in other countries. This suggests that humans may ingest microplastics through food consumption due to the biomagnification of microplastic accumulation in the food chain. Given this elevated level of human exposure to microplastics, there is an urgent need to develop policies to regulate the use, management, and disposal of plastic waste in Thailand.

Convolutional Neural Networks Facilitate River Barrier Detection and Evidence Severe Habitat Fragmentation in the Mekong River Biodiversity Hotspot

AbstractConstruction of river infrastructure, such as dams and weirs, is a global issue for ecosystem protection due to the fragmentation of river habitat and hydrological alteration it causes. Accurate river barrier databases, increasingly used to determine river fragmentation for ecologically sensitive management, are challenging to generate. This is especially so in large, poorly mapped basins where only large dams tend to be recorded. The Mekong is one of the world's most biodiverse river basins but, like many large rivers, impacts on habitat fragmentation from river infrastructure are poorly documented. To demonstrate a solution to this, and enable more sensitive basin management, we generated a whole‐basin barrier database for the Mekong, by training Convolutional Neural Network (CNN)–based object detection models, the best of which was used to identify 10,561 previously unrecorded barriers. Combining manual revision and merged with the existing barrier database, our new barrier database for the Mekong Basin contains 13,054 barriers. Existing databases for the Lower Mekong documented under ∼3% of the barriers recorded by CNN combined with manual checking. The Nam Chi/Nam Mun region, eastern Thailand, is the most fragmented area within the basin, with a median [95% CI] barrier density of 15.53 [0.00–49.30] per 100 km, and Catchment Area‐based Fragmentation Index value, calculated in an upstream direction, of 1,178.67 [0.00–6,418.46], due to the construction of dams and sluice gates. The CNN‐based object detection framework is effective and potentially can transform our ability to identify river barriers across many large river basins and facilitate ecologically‐sensitive management.

Factors Affecting the Nest Survival of Painted Stork (Mycteria leucocephala) at Khao Kheow Open Zoo in Eastern Thailand

Factors Affecting the Nest Survival of Painted Stork (Mycteria leucocephala) at Khao Kheow Open Zoo in Eastern Thailand

Integrative taxonomy reveals two new giant pill-millipedes of the genus Zephronia Gray, 1832 from eastern Thailand (Diplopoda, Sphaerotheriida, Zephroniidae).

A large amount of material of the millipede genus Zephronia Gray, 1832 was collected during 2014-2023 from many parts of eastern Thailand. An integrative study of morphological characters and genetic data (COI gene) revealed two new species: Z.chantaburiensis Srisonchai & Wesener, sp. nov. and Z.macula Srisonchai & Wesener, sp. nov. The two new species clearly differ from other congeners by their unique characteristics, especially in their colour pattern and telopod shape. The interspecific genetic distances of the 658 bp COI gene barcoding fragment between these new species and all other species of giant pill-millipede from Thailand, Laos and Cambodia are 12.01-23.49% for Z.chantaburiensis sp. nov. and 17.93-25.13% for Z.macula sp. nov. While relationships among species remain preliminary, the phylogenetic tree shows that species of Zephronia are interspersed with species of Sphaerobelum Verhoeff, 1924 and Prionobelum Verhoeff, 1924. Phylogenetic analyses place both new species in a clade termed Zephronia s.s., which receives support also from morphological data, showing a unique position of the organ of Tömösváry. Z.macula sp. nov. appears to occur over a broad distribution whereas Z.chantaburiensis sp. nov. was found only at the type locality. Given that all known records are in the eastern part of Thailand, we thus regard both species as endemic. Morphological illustrations based on SEM micrographs and a distribution map are also provided.

Survey of bovine leukemia virus genotypes from Thai swamp buffaloes raised in central and eastern Thailand

Survey of bovine leukemia virus genotypes from Thai swamp buffaloes raised in central and eastern Thailand

Factors Affecting the Nest Survival of Painted Stork (Mycteria leucocephala) at Khao Kheow Open Zoo in Eastern Thailand

Factors Affecting the Nest Survival of Painted Stork (Mycteria leucocephala) at Khao Kheow Open Zoo in Eastern Thailand

Proximal ejecta of the Bolaven extraterrestrial impact, southern Laos.

Sediments in southern Laos and eastern Thailand confirm that the Australasian tektite strewn field came from an extraterrestrial impact crater on the Bolaven Plateau of southern Laos. The principal evidence is the Bolaven diamicton, a pebbly to bouldery breccia that is thickest and coarsest on the plateau. Tektites, the melted target material strewn widely by the forces of the impact 789.0 ± 1.8 ka ago, lie either within the uppermost part of the diamicton or atop it. On the flanks of the plateau, the basal diamicton often contains clasts from preimpact lavas and gravels and sometimes mantles broken Mesozoic bedrock. Locally, its upper portions contain unweathered boulders of basalt or sandstone. Its sharp upper contact with a thick sandy silt implies that the two beds formed in rapid succession. These characteristics of the Bolaven diamicton show that it resulted primarily from the excavation, comminution, and launch of sandstone and weathered basaltic lavas from a crater on the Bolaven Plateau, and entrained other materials while in transit.

Influence of COVID-19 on the emergence of stone-tool use behavior in a population of common long-tailed macaques (Macaca fascicularis fascicularis) in Thailand.

Stone tool use is a rare behavior across nonhuman primates. Here we report the first population of common long-tailed macaques (Macaca fascicularis fascicularis) who customarily used stone tools to open rock oysters (Saccostrea forskali) on a small island along the Thai Gulf in Koh Ped (KPE), eastern Thailand. We observed this population several times during the past 10 years, but no stone-tool use behavior was observed until our survey during the coronavirus disease 2019 (COVID-19) pandemic in July 2022. KPE is located in Pattaya City, a hotspot for tourism in Thailand. Tourists in this area frequently provided large amounts of food for the monkeys on KPE. During the COVID-19 curfew, however, tourists were not allowed to access the island, and monkeys began to face food scarcity. During this time, we observed stone-tool use behavior for the first time on KPE. Based on our observations, the first tool manipulation was similar to stone throwing (a known precursor of stone tool use). From our observations in March 2023, we found 17 subadult/adult animals performing the behavior, 15 of 17 were males and mostly solitary while performing the behavior. The M. f. fascicularis subspecies was confirmed by distribution, morphological characteristics, and mtDNA and SRY gene sequences. Taken together, we proposed that the stone tool use behavior in the KPE common long-tailed macaques emerged due to the COVID-19 food scarcity. Since traveling is no longer restricted many tourists have started coming back to the island, and there is a high risk for this stone tool-use behavior to disappear within this population of long-tailed macaques.

Curcuma ubonensis (Zingiberaceae), a new species of Curcuma subgen. hitcheniopsis from Eastern Thailand

Curcuma ubonensis Boonma, Saensouk, Maknoi & P. Saensouk sp. nov. (Zingiberaceae) was recently discovered in Ubon Ratchathani Province, Eastern Thailand. Specimen identification involves comparing their morphology with descriptions in similar species' protologues. We performed measurements on specimens collected from their natural habitats, both living and preserved. Despite its resemblances with Curcuma prasina Škorničk. in having greenish inflorescence with small purple flowers that lack of epigynous glands, yet this novel species displays distinct features of a brownish-red margin of petiole (vs. C. prasina has green margin), lamina elliptic, 3.8-7.0 cm wide, margin brownish red (vs. narrowly elliptic, 1.5-3.2 cm wide, margin green); coma bract present (vs. absent), fertile bracts uniquely triangular-obovate, apex rounded (vs. almost orbicular, apex acute), and labellum reddish purple with four white stripes by two stripes rarely pale yellow extending from the basal to half of the sinus, and another two stripes from the basal along the longitudinally of each lobe to half the length of the lobe, with yellow at the middle groove of the labellum almost to the base (vs. purple with a bright yellow and swollen median band composed of two central lines extending from the base to about two-thirds the length of the labellum towards the apex, sides of the labellum with paler lines radiating towards the margin). Meticulous examination and morphological comparison of Curcuma ubonensis with related species within the Curcuma genus reveals its novelty. We comprehensively accounted for its morphological traits, including illustrations, vernacular name, ecological preferences, phenology, distribution, traditional uses, conservation status, distribution map, and a comparative table to its ally species. Furthermore, we present an updated identification key for differentiating species within the Curcuma subgenus Hitcheniopsis in Thailand.

Short Communication: The oleaginous Candida tropicalis isolated from mangrove soil in eastern Thailand and the fatty acid composition profile of its intracellular lipids

Abstract. Wongchamrearn S, Boontanom P, Ungwiwatkul S, Emnin N, Chantarasiri A. 2023. Short Communication: The oleaginous Candida tropicalis isolated from mangrove soil in eastern Thailand and the fatty acid composition profile of its intracellular lipids. Biodiversitas 24: 5088-5095. Oleaginous yeasts are microorganisms that can accumulate intracellular lipids at a rate of more than 20% of their cell dry weight. They are considered ideal microbes for a sustainable bioeconomy and a promising source for biotechnological applications. Thus, the exploration of efficient oleaginous yeasts from various environments is necessitated. At present, the number of oleaginous yeasts that have been discovered from mangrove environments remains scarce. Therefore, this study isolated and screened for lipid-accumulating yeast strains in mangrove soil samples collected from Rayong Province and Chonburi Province, Thailand. The intracellular lipids of isolated yeasts were extracted and quantitatively analyzed to evaluate the efficient oleaginous strains. Fifteen yeast strains were considered lipid-accumulating yeasts based on the Sudan IV staining method and lipid content determination, with intracellular lipid accumulation ranging from 5.71±1.89% (w/w) to 33.83±1.41% (w/w). The isolated yeast strain MJ13 was designated the most efficient oleaginous strain and subsequently genetically identified as Candida tropicalis. The fatty acid composition of its intracellular lipids was analyzed by gas chromatography, which consisted of five saturated fatty acids and five unsaturated fatty acids with 10-22 carbon atoms. The predominant fatty acids were palmitic (C16:0) and stearic (C18:0) acids. Some fatty acids essential to the human body and pharmacological sciences were detected, involving a-linolenic (C18:3n3) and cis-13,16-docosadienoic (C22:2) acids. This oleaginous yeast strain could be applied in lipid-related biofuel and high-value bioeconomy applications.

Prediction of Au-Associated Minerals in Eastern Thailand Based on Stream Sediment Geochemical Data Analysis by S-A Multifractal Model

Conducted within the scope of geochemical exploration in eastern Thailand, this study aims to detect geochemical anomalies and potential mineral deposits. The objective was to interpret intricate spatial dispersion patterns and concentration levels of deposit pathfinder elements, specifically arsenic (As), copper (Cu), and zinc (Zn), using a comprehensive array of stream sediment geochemistry data. Methodologies involved integrating multifractal properties and traditional statistics, facilitated by the GeoDAS and ArcGIS platforms as instrumental analytical tools. In total, 5376 stream sediment samples were collected and evaluated, leading to the development of an in-depth geochemical map. The results indicated distinct geological units marked by substantially elevated average values of the aforementioned elements. Identification of geochemical anomalies was achieved through the spatial distribution method and the subsequent application of the spectrum-area (S-A) multifractal model. An intriguing link was found between high As concentrations and gold deposits in the area, suggesting As as a viable pathfinder element for gold mineralization. The anomaly maps, generated from the stream sediment data, spotlighted potential zones of interest, offering valuable guidance for future mineral exploration and geological inquiries. Nonetheless, it is vital to recognize that the increased values noted in these maps may be influenced by regional geological factors, emphasizing the necessity for a diverse set of analytical methods for accurate interpretation. This study’s significance lies in its pioneering use of the S-A multifractal model in geochemical data analysis. This innovative approach has deepened our comprehension of geochemical dispersion patterns and improved the precision of mineral exploration.

A Report of Fungi Associated With the Scarred-Scabbed Symptoms on Maprang (Bouea macrophylla Griffith) in Eastern Thailand

A Report of Fungi Associated With the Scarred-Scabbed Symptoms on Maprang (Bouea macrophylla Griffith) in Eastern Thailand

Limited Polymorphism in the Dihydrofolate Reductase (dhfr) and dihydropteroate synthase genes (dhps) of Plasmodium knowlesi isolate from Thailand

BackgroundThe 2022 malaria WHO reported around 4000 P. knowlesi infections in the South-East Asia region. In the same period, 72 positive cases were reported by the Department of Disease Control in Thailand, suggesting a persistent infection. Little is known about dihydrofolate reductase (pkdhfr) and dihydropteroate synthase (pkdhps), putative antimalarial resistance markers for P. knowlesi. The relevant amplification and sequencing protocol are presently unavailable. In this study, we developed a protocol for amplifying and evaluating pkdhps mutations. The haplotype pattern of pkdhfr–pkdhps in Thai isolates was analyzed, and the effects of these pkdhps mutations were predicted by using a computer program. MethodsPkdhps were amplified and sequenced from 28 P. knowlesi samples collected in 2008 and 2020 from nine provinces across Thailand. Combining pkdhfr sequencing data from previous work with pkdhps data to analyze polymorphisms of pkdhfr and pkdhps haplotype. Protein modeling and molecular docking were constructed using two inhibitors, sulfadoxine and sulfamethoxazole, and further details were obtained through analyses of protein–ligand interactions by using the Genetic Optimisation for Ligand Docking program. A phylogenetic tree cluster analysis was reconstructed to compare the P. knowlesi Malaysia isolates. ResultsFive nonsynonymous mutations in the pkdhps were detected outside the equivalence of the binding pocket sites to sulfadoxine and sulfamethoxazole, which are at N391S, E421G, I425R, A449S, and N517S. Based on the modeling and molecular docking analyses, the N391S and N517S mutations located close to the enzyme-binding pocket demonstrated a different docking score and protein–ligand interaction in loop 2 of the enzyme. These findings indicated that it was less likely to induce drug resistance. Of the four haplotypes of pkdhfr–pkdhps, the most common one is the R34L pkdhfr mutation and the pkdhps quadruple mutation (GRSS) at E421G, I425R, A449S, and N517S, which were observed in P. knowlesi in southern Thailand (53.57%). Based on the results of neighbor-joining analysis for pkdhfr and pkdhps, the samples isolated from eastern Thailand displayed a close relationship with Cambodia isolates, while southern Thailand isolates showed a long branch separated from the Malaysian isolates. ConclusionsA new PCR protocol amplification and evaluation of dihydropteroate synthase mutations in Knowlesi (pkdhps) has been developed. The most prevalent pkdhfr-pkdhps haplotypes (53.57%) in southern Thailand are R34L pkdhfr mutation and pkdhps quadruple mutation. Further investigation requires additional phenotypic data from clinical isolates, transgenic lines expressing mutant alleles, or recombinant proteins.

The role of academic procrastination on Internet addiction among Thai university students: A cross-sectional study.

The internet has become an inevitable tool for information-seeking and communication in today's modern era. However, ironically it has driven humankind to become more dependent, leading to addiction. Internet addiction has increased exponentially at all levels of society, especially university students, impeding their physical, psychological, and social well-being. This study aimed to examine the relationship between academic procrastination and internet addiction and determine the influence of academic procrastination on internet addiction among Thai university students. A cross-sectional study was conducted involving 470 participants selected through multi-stage cluster random sampling from a university in eastern Thailand. The data collection was conducted between 29 November 2022 and 27 January 2023. The data were gathered using a demographic data form, an internet addiction test, and a procrastination assessment scale for the students' questionnaire. Descriptive statistics, Pearson correlation coefficient, and simple linear regression were employed for data analysis. The results revealed that academic procrastination (M = 49.68, SD = 12.61) and internet addiction (M = 65.26, SD = 5.60) were at a moderate level. A positive correlation was identified between academic procrastination and internet addiction (r = 0.33, p <0.01), indicating a low relationship. Academic procrastination also had a significant predictive power on internet addiction, accounting for 11.3% of the variance (R2 adjusted = 0.113, F (1, 468) = 59.583, p <0.001). The findings indicated the significant role of academic procrastination on internet addiction. Therefore, it is crucial that nurses should formulate interventions by considering this factor and emphasize self-regulatory and time-management skills and practical ways to limit internet dependence. Furthermore, the findings suggest that nurses could assess the procrastination level among students, devise prevention strategies, and organize awareness campaigns to instill information about rational internet use that aids in mitigating the risks and preventing them from getting addicted.

Global Englishes: Textbook Analysis and Teachers’ Perception

This study investigated the manifestation of Global Englishes features in three English textbooks commonly used in the lower secondary schools of eastern Thailand. It further explored whether the teachers who used the textbooks were aware of the Global Englishes features manifested in the textbooks. The data revealed that Global Englishes features were primarily taken for granted when designing the three English textbooks. In contrast to the Global Englishes paradigm, the three English textbooks mainly represented the target interlocutors, ownership of English, and norms of English from &amp;lsquo;native&amp;rsquo; English-speaking (NES) countries. Even though attempts were made to include some diversity regarding the target interlocutors, it was unbalanced distribution. However, cultural content in reading materials is found to be diversely represented. When exploring teachers&amp;rsquo; perceptions of Global Englishes in the textbooks, it was revealed that they lacked knowledge about Global Englishes. They were aware of cultural diversities in the readings but did not try to discuss them with the students since they perceived reading skills as more important than cultural content. Implications for teacher professional development are discussed.

Temporal Changes in Water Quality with Increasing Ambient Temperatures Affect the Distribution and Relative Abundance of 10 Species of Balitorid Fishes in Small Streams of Eastern Thailand

Stream degradation increases with high anthropogenic activity and climate variability, while declines occur in biodiversity. However, few studies have been undertaken on tropical waterways, a major impediment to biodiversity conservation. The present study was conducted on 95 relatively pristine small streams in Eastern Thailand with 10 reasonably uncommon species of balitorid fishes. Measurements were made of 21 physical and chemical factors and the substrate particle size. Stepwise regression identified the direct importance of substrate particle size and nitrate on the species’ richness of balitorids, whereas its abundance was negatively related with iron concentrations. A Canonical Correspondence Analysis identified three fish groups: the 1st group was negatively correlated with ammonia and positively correlated with dissolved silica, the 2nd group was positively correlated with substrate particle size and negatively correlated with stream ambient temperature and ammonia concentration, and the 3rd group was negatively correlated with low dissolved silica, respectively. The results of this study may indicate the vulnerability of balitorids under climate warming and anthropogenic pressure that alter the water physicochemical factors and river degradation including the substrate type. Thus, a conservation framework should be provided regarding the limits for water temperature, ammonia, and iron in Thailand’s Water Quality Criteria to better protect its freshwater ecosystem. Balitorid is a potential bioindicator for evaluating the river temperature effect in combination with ammonia nutrient stressors as long as the way-of-life habits of the species are taken into account.

Diversity and cellulolytic activity of cellulase-producing bacteria isolated from the soils of two mangrove forests in Eastern Thailand

Abstract. Bamrungpanichtavorn T, Ungwiwatkul S, Boontanom P, Chantarasiri A. 2023. Diversity and cellulolytic activity of cellulase-producing bacteria isolated from the soils of two mangrove forests in Eastern Thailand. Biodiversitas 24: 3891-3902. The Southeast Asian countries hold the largest proportion of the world's mangrove area. Mangrove forests are a potential source for the isolation of economic microbial enzymes. Cellulases are a widely used microbial enzyme for cellulose degradation in various industries. Therefore, this study aimed to isolate, genetically identify, and enzymatically characterize cellulase-producing bacteria from the soils of two mangrove forests in Eastern Thailand. Twenty-six cellulase-producing bacteria were isolated and subsequently genotyped by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) analysis of the 16S rRNA genes. Thirteen different RFLP patterns were obtained and genetically analyzed into six bacterial genera comprising Aeromonas, Bacillus, Chryseobacterium, Lysinibacillus, Pseudomonas, and Vibrio. The Bacillus species were the predominant cellulase-producing bacteria in the study sites. Moreover, the cellulase-producing Chryseobacterium and Lysinibacillus had hardly ever been reported. The Bacillus sp. strain RY08B was the most active cellulase-producing bacterium with 1.510±0.060 U/mL of CMCase activity. The optimum temperature and pH for the CMCase activity were determined to be 50°C at a pH of 7.0 with a thermal stability range of 25-50°C at a pH of 7.0. This bacterium could be applied in several environmentally friendly industries requiring mild conditions for their production processes.

Client assessments of their audit experiences: the role of experience quality, similarity and client participation

PurposeThis study examines how three psychological factors (i.e. perceived experience quality, perceived similarity and client participation) that impact client evaluations of their recent audit experiences influence client satisfaction and trustworthiness, which, in turn, affect advocacy in an small- and medium-sized enterprise (SME) context. Furthermore, the study investigates whether the influence of the three psychological factors on client satisfaction and trustworthiness is contingent on client expertise.Design/methodology/approachThe sample consisted of 744 SME executives from the following four regions: central, northern, eastern and southern Thailand. Data were collected using a survey questionnaire. Confirmatory factor analysis was conducted to ensure the reliability and validity of the scale before structural equation modeling was applied to analyze the data.FindingsThe results showed significant positive effects of the three psychological factors (perceived experience quality, perceived similarity and client participation) on client satisfaction and perceived trustworthiness. The moderating role of client expertise on the relationships is also found. More specifically, client expertise positively moderated the connections between experience quality and satisfaction, experience quality and trustworthiness and client participation and trustworthiness. Conversely, client expertise negatively moderated the similarity–satisfaction and similarity–trustworthiness relationships.Originality/valueThis study contributes to the audit literature by examining the role of psychological factor that impacts client satisfaction and perceived trustworthiness in the SME context. Moreover, the moderating role of client expertise is examined for the first time, providing new insights into the boundary condition of the relationship.

Incidence, genetic diversity, and antimicrobial resistance profiles of Vibrio parahaemolyticus in seafood in Bangkok and eastern Thailand.

Emergence of Vibrio parahaemolyticus pandemic strain O3:K6 was first documented in 1996. Since then it has been accounted for large outbreaks of diarrhea globally. In Thailand, prior studies on pandemic and non-pandemic V. parahaemolyticus had mostly been done in the south. The incidence and molecular characterization of pandemic and non-pandemic strains in other parts of Thailand have not been fully characterized. This study examined the incidence of V. parahaemolyticus in seafood samples purchased in Bangkok and collected in eastern Thailand and characterized V. parahaemolyticus isolates. Potential virulence genes, VPaI-7, T3SS2, and biofilm were examined. Antimicrobial resistance (AMR) profiles and AMR genes (ARGs) were determined. V. parahaemolyticus was isolated from 190 marketed and farmed seafood samples by a culture method and confirmed by polymerase chain reaction (PCR). The incidence of pandemic and non-pandemic V. parahaemolyticus and VPaI-7, T3SS2, and biofilm genes was examined by PCR. AMR profiles were verified by a broth microdilution technique. The presence of ARGs was verified by genome analysis. V. parahaemolyticus characterization was done by multilocus sequence typing (MLST). A phylogenomic tree was built from nucleotide sequences by UBCG2.0 and RAxML softwares. All 50 V. parahaemolyticus isolates including 21 pathogenic and 29 non-pathogenic strains from 190 samples had the toxRS/old sequence, indicating non-pandemic strains. All isolates had biofilm genes (VP0950, VP0952, and VP0962). None carried T3SS2 genes (VP1346 and VP1367), while VPaI-7 gene (VP1321) was seen in two isolates. Antimicrobial susceptibility profiles obtained from 36 V. parahaemolyticus isolates revealed high frequency of resistance to colistin (100%, 36/36) and ampicillin (83%, 30/36), but susceptibility to amoxicillin/clavulanic acid and piperacillin/tazobactam (100%, 36/36). Multidrug resistance (MDR) was seen in 11 isolates (31%, 11/36). Genome analysis revealed ARGs including blaCARB (100%, 36/36), tet(34) (83%, 30/36), tet(35) (42%, 15/36), qnrC (6%, 2/36), dfrA6 (3%, 1/36), and blaCTX-M-55 (3%, 1/36). Phylogenomic and MLST analyses classified 36 V. parahaemolyticus isolates into 5 clades, with 12 known and 13 novel sequence types (STs), suggesting high genetic variation among the isolates. Although none V. parahaemolyticus strains isolated from seafood samples purchased in Bangkok and collected in eastern Thailand were pandemic strains, around one third of isolates were MDR V. parahaemolyticus strains. The presence of resistance genes of the first-line antibiotics for V. parahaemolyticus infection raises a major concern for clinical treatment outcome since these resistance genes could be highly expressed under suitable circumstances.