Publications by authors named "Sasimanas Unajak"

, a pathogen of significant concern in animal production, companion animal health, and public health, particularly affects immunocompromised individuals and pregnant women. Current diagnostic techniques employ both direct and indirect methods, with serological assays widely used for detecting infections in humans and animals. In this study, the TIM-barrel structure of Br2 -glucosidase was engineered to create 10 chimeric multi-epitope proteins for serological detection.

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Vibriosis caused by is a major problem in aquatic animals, particularly brown marble groupers (). biotype I has recently been isolated and classified into subgroups SUKU_G1, SUKU_G2, and SUKU_G3 according to the different types of virulence genes. In a previous study, we have shown that biotype I strains were classified into three subgroups according to the different types of virulence genes, which exhibited different phenotypes in terms of growth rate and virulence.

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  • Amphotericin B (AmB) is a strong antifungal and antiparasitic drug that kills leishmanial parasites by disrupting their cell membranes, making it important to study its effects on parasites like Leishmania orientalis to understand potential drug resistance.
  • This study involved exposing a specific Leishmania orientalis strain to AmB and analyzing genetic changes through sequencing methods, focusing on single nucleotide polymorphisms (SNPs) and gene expression changes.
  • The results indicated no significant chromosomal alterations post-treatment, but a higher incidence of SNPs in the control group, along with the downregulation of key genes, suggesting complex regulatory mechanisms might contribute to AmB resistance in this strain.
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  • Asian seabass is a crucial species in Thai aquaculture but faces challenges from infectious diseases like photobacteriosis, caused by the bacterium Photobacterium damselae.
  • Researchers isolated and identified various strains of P. damselae, finding that all were resistant to amoxicillin and categorized them by their biological activity.
  • The study identified one highly virulent strain (SK136) and demonstrated that preliminary vaccination using formalin-killed cells could protect Asian seabass from infections, laying the groundwork for future vaccine development.
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The Strep Easy Kit, a bio-enrichment dual ICG-strip test, is a diagnostic tool designed for the detection of Streptococcus agalactiae, an important pathogenic bacterium in tilapia farming. The kit can simultaneously identify two different serotypes of S. agalactiae, serotype Ia and serotype III.

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Regarding several infectious diseases in fish, multiple vaccinations are not favorable. The chimeric multiepitope vaccine (CMEV) harboring several antigens for multi-disease prevention would enhance vaccine efficiency in terms of multiple disease prevention. Herein, the immunogens of tilapia's seven pathogens including E.

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Nitrofuran (NF) contamination in food products is a global problem resulting in the banned utilization and importation of nitrofuran contaminated products. A novel chromogenic detection method using a specific DNA aptamer with high affinity and specificity to nitrofurans was developed. Single-stranded DNA aptamers specific to nitrofuran metabolites, including 3-amino-2-oxazolidinone (AOZ), 3-amino-5-methylmorpholino-2-oxazolidinone (AMOZ), and 1-aminohydantoin (AHD), were isolated using magnetic bead-SELEX.

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An electrochemical aptasensor was developed for the determination of chloramphenicol (CAP) in fresh foods and food products. The aptasensor was developed using Prussian blue (PB) and chitosan (CS) film. PB acts as a redox probe for detection and CS acts as a sorption material.

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  • Mitochondrial DNAs (mtDNAs) are important for studying evolutionary relationships and species identification, particularly in eukaryotes, while kinetoplast DNAs (kDNAs) in kinetoplastids have a complex structure, comprising maxicircles and minicircles.
  • This study focused on the kDNAs of a newly examined species, Leishmania orientalis strain PCM2, utilizing hybrid genome sequencing to analyze and reconstruct its kDNA sequences.
  • The research discovered high similarity between L. orientalis maxicircle and another strain, L. enriettii, and identified multiple classes of minicircles, providing genetic insights that may assist in diagnosis and understanding the parasite's genetics in Thailand.
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Lactic acid bacteria (LAB) were screened from (red sea bass), and their antimicrobial activities were evaluated against two species isolated from the , namely, (AV) and (AJ). Three LAB isolates, MU8 (EF_8), MU2 (EFL_2), and MU9 (EFL_9), were found to inhibit both AV and AJ; however, their cell-free supernatant (CFS) did not do so. Interestingly, bacteriocin-like substances (BLS) induced by cocultures of EF_8 with AV exhibited the highest antimicrobial activity against both sp.

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Acute hepatopancreatic necrosis disease (AHPND) is a serious bacterial disease affecting shrimp aquaculture worldwide. In this study, natural microbes were used in disease prevention and control. Probiotics derived from spp.

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The phylogenetic relationship of living Thai Donacidae was herein studied. Two methodologies, geometric morphometrics (GM) and genetic analysis of sequences, were combined and applied to identify the valid taxa and explain biodiversity and the distribution pattern in this family. A total of 587 living specimens were tested to analyze the shape and size patterns by Elliptic Fourier Analysis (EFA).

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  • - This study focuses on the mitochondrial DNA, or kinetoplast DNA (kDNA), of Leishmania martiniquensis, a species prevalent in Thailand, which is linked to drug resistance and survival in these parasites.
  • - Researchers extracted and reconstructed the complete maxicircle (19,008 bp) and identified 214 classes of minicircles from the L. martiniquensis strain PCM3 using advanced whole-genome sequencing techniques.
  • - The findings reveal close structural similarities between the maxicircle of L. martiniquensis and other Leishmania species, while phylogenetic analysis shows distinct evolution among the minicircles, paving the way for improved diagnostic and monitoring tools for this parasite.
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Streptococcosis is one of the major diseases that causes devastation to farmed fish, leading to significant economic losses all around the world. Currently, two serotypes of Streptococcus agalactiae, serotype Ia and III, have been identified as virulent strains and major causative agents of the disease in farmed Nile tilapia (Oreochromis niloticus Linn.) in Thailand.

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Leishmaniasis is a parasitic disease caused by protozoan flagellates of the genus . Recently, and , emerging species of , were isolated from patients in Thailand. Development of the vaccine is demanded; however, genetic differences between the two species make it difficult to design a vaccine that is effective for both species.

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  • The study focuses on the genomic analysis of a neglected strain in Thailand, presenting a new bioinformatic workflow that combines de novo assembly and reference-based methods to generate high-quality genomic drafts from Illumina sequencing data.
  • Using this integrated approach, researchers produced a genomic draft of isolate PCM2, revealing important characteristics such as 3367 contigs and 8887 predicted genes, along with significant integrity and coverage compared to an existing reference genome.
  • The findings suggest that the proposed workflow is effective in generating a valuable genome for further analysis, which could aid in identifying strain-specific markers and virulence genes for drug and vaccine development.
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Protease enzymes contribute to the initiation of cardiac remodeling and heart failure after myocardial ischemic/reperfusion (I/R) injury. Protease inhibitors attenuate protease activity and limit left ventricular dysfunction and remodeling. Previous studies showed the cardioprotective effect of secretory leukocyte protease inhibitor (SLPI) against I/R injury.

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Tilapia lake virus (TiLV) now affects Nile tilapia culture worldwide, with no available commercial vaccine for disease prevention. DNA and recombinant protein-based vaccines were developed and tested following viral isolation and characterization. The viral strain isolated from diseased hybrid red tilapia ( sp.

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Generally, the injection method is recommended as the best efficient method for vaccine applications in fish. However, labor-intensive and difficult injection for certain fish sizes is always considered as a limitation to aquatic animals. To demonstrate the effectiveness of a novel oral delivery system for the piscine vaccine with nano-delivery made from nano clay, halloysite nanotubes (HNTs) and their modified forms were loaded with killed vaccines, and we determined the ability of the system in releasing vaccines in a mimic digestive system.

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Inhibition of proteases shows therapeutic potential. Our previous studies demonstrated the cardioprotection by the Secretory Leukocyte Protease Inhibitor (SLPI) against myocardial ischaemia/reperfusion (I/R) injury. However, it is unclear whether the cardioprotective effect of SLPI seen in our previous works is due to the inhibition of protease enzymes.

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  • Autochthonous leishmaniasis, caused by protozoan parasites, is reported in both immunocompromised and immunocompetent patients in southern Thailand, yet knowledge on its genetics is limited, especially compared to northern isolates.
  • Researchers sequenced and analyzed the genomes of two southern isolates (PCM2 and PCM3) alongside other species, finding notable differences in genome size and protein variations that suggest distinct strains.
  • The study highlights six protein groups linked to virulence and drug resistance, emphasizing the importance of ongoing genetic monitoring of these parasites in Thailand and surrounding areas.
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For the past several decades, aquaculture all around the world have been retarded by various disease outbreaks caused by many pathogens including parasites, bacteria, and viruses. Apart from being harmful to human health, the emerging diseases also dramatically affect the farm animals such as livestock and aquatic animals. To cope with this problem, one of the effective prophylactic measures is the application of vaccine.

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Animals provide food and clothing in addition to other value-added products. Changes in diet and lifestyle have increased the consumption and the use of animal products. Infectious diseases in animals are a major threat to global animal health and its welfare; their effective control is crucial for agronomic health, for safeguarding food security and also alleviating rural poverty.

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Tropomyosin is a major allergen responsible for cross-allergenicity in a number of shellfish species. Although extensively characterized in marine crustaceans, the information of tropomyosin is limited to a few freshwater crustacean species. As a result, more cross-reactivity evidence and information of tropomyosin at the molecular level are required for the detection of freshwater crustaceans in the food industry.

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Objective: An aptamer specifically binding to diethyl thiophosphate (DETP) was constructed and incorporated in an optical sensor and electrochemical techniques to enable the specific measurement of DETP as a metabolite and a biomarker of organophosphate exposure.

Results: A DETP-bound aptamer was selected from the library using capillary electrophoresis-systematic evolution of ligands by exponential enrichment (CE-SELEX). A colorimetric method revealed that the aptamer had the highest affinity for DETP, with a mean K value (± SD) of 0.

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