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Background: Burkholderia pseudomallei is a soil- and water-dwelling bacterium that causes the life-threatening infection melioidosis. Patients typically acquire this infection through environmental exposure, so reducing B. pseudomallei levels in the environment could mitigate the risk of infection. Trichoderma asperellum is a biological control agent that synthesizes a diverse range of antimicrobial substances targeting other microorganisms. This study therefore examined the antibacterial and anti-biofilm activities of T. asperellum culture filtrate against B. pseudomallei ., Methods: The antibacterial activities of T. asperellum culture filtrates, collected at various time intervals, were assessed against B. pseudomallei using the agar well diffusion method. Subsequently, the minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), and anti-biofilm activities of the culture filtrate exhibiting the highest inhibitory effect were determined. Bactericidal efficacy was further evaluated via a time-kill assay. The mechanisms underlying inhibition were then investigated using scanning electron microscopy and crystal violet uptake assays., Results: Filtrate collected from 7-day old cultures of T. asperellum (TD7) exhibited the strongest inhibitory effect on B. pseudomallei , with an inhibition zone of 30.33 ± 0.19 mm. The MIC of TD7 against B. pseudomallei was 7.81 ± 0.00 mg/mL and the MBC ranged from 7.81 ± 0.00 to 11.72 ± 1.75 mg/mL. Time-kill studies with TD7 confirmed its bactericidal activity, with complete elimination of B. pseudomallei occurring within 30 min treatment at 62.48 mg/mL (8xMIC) and 24 h treatment at 7.81 mg/mL (1xMIC). At a concentration of  7.81 mg/mL, TD7 also significantly reduced B. pseudomallei biofilm formation. Scanning electron microscopy revealed surface roughening and cell shrinkage of TD7-treated B. pseudomallei . TD7-treated bacteria were also found to absorb more crystal violet dye than untreated cells, indicating that TD7 might inhibit and kill B. pseudomallei by disrupting cell membrane permeability., Conclusions: Our findings demonstrate that T. asperellum culture filtrates possess bactericidal activity and effectively disrupt biofilm formation by B. pseudomallei . This suggests that T. asperellum could potentially be used to reduce the presence of B. pseudomallei in the environment and, consequently, lower the incidence of melioidosis., Competing Interests: The authors declare there are no competing interests., (©2025 Roopkhan et al.)

Introduction: Malayemys khoratensis is a freshwater turtle species endemic to northeastern Thailand and Lao PDR. While M. khoratensis is relatively common and widespread in Thailand, its population size and demographic trends remain largely unknown, as direct population estimates are lacking. This species faces significant threats from consumption, exploitation, and trade. Therefore, this study aims to investigate the genetic diversity, population structure, and demographic trends of M. khoratensis in northeastern Thailand, using two mitochondrial DNA genes, Cyt b and ND4 ., Method: We grouped the turtles based on three major river basins in northeastern Thailand: Mun, Chi, and Northeast Mekong to assess population structure and test the isolation-by-basin hypothesis. The Cyt b and ND4 genes of 49 M. khoratensis individuals across 15 provinces in Thailand were sequenced, and 15 sequences from a previous study of Ihlow et al. (2016) were included into the analyses. We constructed a haplotype network from the concatenated sequences and analyzed the population structure with the analysis of molecular variance (AMOVA). Additionally, we used a Bayesian Skyline plot (BSP) analysis to estimate the effective female population size and explore the demographic history of this species., Results: Our analysis identified 13 unique haplotypes defined by 26 polymorphic sites from 64 samples. The total haplotype diversity for M. khoratensis was 0.819, while nucleotide diversity was 0.0031. The haplotype network and AMOVA revealed no distinct population structure among the river basins, suggesting gene flow across these regions. The BSP estimated a stable effective female population size of approximately 130,000 individuals since around 100,000 years ago (late Pleistocene)., Conclusion: Our findings indicated no significant population structure by river basin, which may be due to natural movement between basins or potential human-mediated translocations linked to the turtle trade. The demographic trend of M. khoratensis appears to have been stable over time. However, given the ongoing exploitation of this species, we recommend regular monitoring of population trends to support its long-term survival., Competing Interests: The authors declare that they have no competing interests., (© 2024 Chaianunporn et al.)

The invasion of blackchin tilapia in Thailand is a critical ecological threat affecting native biodiversity and destabilizing ecosystems. It is also resulting in significant ecological and socio-economic impacts. Originally from West Africa and introduced globally for aquaculture, blackchin tilapia thrive in Thailand's brackish and freshwater ecosystems because of their high reproductive rates, environmental adaptability, and trophic plasticity. This review evaluates potential solutions for the invasion of blackchin tilapia in Thailand from a scientific perspective. The successful invasion of blackchin tilapia in Thailand can be attributed to several key factors, including late detection of the species, the delayed government response, the absence of effective management strategies, and the species' high invasive potential. Given its wide distribution, large population size, and high reproductive rate, the eradication of the entire blackchin tilapia population is unlikely. Management efforts should focus on containment and impact reduction. Early detection and monitoring at the invasion front remain crucial to limit the species' spread. Developing an online platform for tracking invasive species would aid these efforts. Public education and outreach are essential for promoting responsible behaviors for preventing further spread. Encouraging the utilization of blackchin tilapia as a food source and for commercial purposes could help suppress its population while supporting local economies. Biological control and other potentially harmful strategies should be avoided unless supported by strong scientific evidence to ensure minimal risks to ecosystems. Scientific research into controlling blackchin tilapia should be encouraged to develop suitable strategies, including using sterile triploid tilapia. The "polluter pays" policy should be implemented to cover the costs associated with invasive species. Coordinated efforts between researchers, policymakers, and the public are crucial for formulating effective management strategies to promote a balance between economic benefits and long-term environmental sustainability.

In Thailand, two snail-eating turtle species in the genus Malayemes (M. subtrijuga and M. macrocephala) are protected animals in which smuggling and trading are illegal. Recently, a new species M. khoratensis has been reported and it has not yet been considered as protected animal species. To enforce the law, species identification of Malayemes is crucial. However, it is quite challenging and requires expertise. Therefore, a simple tool, such as image analysis, to differentiate these three snail-eating species would be highly useful. This study proposes a novel ensemble multiview image processing approach for the automated classification of three turtle species in the genus Malayemys. The original YOLOv8 architecture was improved by utilizing a convolutional neural network (CNN) to overcome the limitations of traditional identification methods. This model captures unique morphological features by analyzing Malayemys species images from various angles, addressing challenges such as occlusion and appearance variations. The ensemble multiview strategy significantly increases the YOLOv8 classification accuracy using a comprehensive dataset, achieving an average mean average precision (mAP) of 98% for the genus Malayemys compared with the nonensemble multiview and single-view strategies. The species identification accuracy of the proposed models was validated by comparing genetic methods using mitochondrial DNA with morphological characteristics. Even though the morphological characteristics of these three species are ambiguous, the mitochondrial DNA sequences are quite distinct. Therefore, this alternative tool should be used to increase confidence in field identification. In summary, the contribution of this study not only marks a significant advancement in computational biology but also supports wildlife and turtle conservation efforts by enabling rapid, accurate species identification., (© 2024. The Author(s).)

The idea that populations are spatially structured has become a very powerful concept in ecology, raising interest in many research areas. However, despite dispersal being a core component of the concept, it typically does not consider the movement behavior underlying any dispersal. Using individual-based simulations in continuous space, we explored the emergence of a spatially structured population in landscapes with spatially heterogeneous resource distribution and with organisms following simple area-concentrated search (ACS); individuals do not, however, perceive or respond to any habitat attributes per se but only to their foraging success. We investigated the effects of different resource clustering pattern in landscapes (single large cluster vs. many small clusters) and different resource density on the spatial structure of populations and movement between resource clusters of individuals. As results, we found that foraging success increased with increasing resource density and decreasing number of resource clusters. In a wide parameter space, the system exhibited attributes of a spatially structured populations with individuals concentrated in areas of high resource density, searching within areas of resources, and "dispersing" in straight line between resource patches. "Emigration" was more likely from patches that were small or of low quality (low resource density), but we observed an interaction effect between these two parameters. With the ACS implemented, individuals tended to move deeper into a resource cluster in scenarios with moderate resource density than in scenarios with high resource density. "Looping" from patches was more likely if patches were large and of high quality. Our simulations demonstrate that spatial structure in populations may emerge if critical resources are heterogeneously distributed and if individuals follow simple movement rules (such as ACS). Neither the perception of habitat nor an explicit decision to emigrate from a patch on the side of acting individuals is necessary for the emergence of such spatial structure., (© 2022 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

Destruction of natural habitat, land-use changes and biological invasion are some of the major threats to biodiversity. Both habitat alteration and biological invasions can have impacts on pollinator communities and pollination network structures. This study aims to examine the effect of an invasive plant, praxelis ( Praxelis clematidea ; Asteraceae), and land-use types on pollinator communities and the structure of pollination networks. We conducted the study in smallholder orchards which are either invaded or non-invaded by P. clematidea . We estimated the pollinator richness, visitation rates, and pollinator diversity and evaluated the network structures from 18 smallholder orchards in Northeastern Thailand. The effect of landscape structure in the vicinity of the orchards was investigated, with the proportion of agricultural, forest, and urban landscape within a 3 km radius analyzed. The invasive species and land-use disturbance influence the pollinator communities and pollination network structure at species level was affected by the presence of P. clematidea . Bees were the most important pollinator group for pollinator communities and pollination networks of both invaded or non-invaded plots, as bees are a generalist species, they provide the coherence of both the network and its own module. The urban landscape had a strong negative influence on pollinator richness, while the proportions of agriculture and forest landscape positively affected the pollinator community.

Species may respond to climate change in many ecological and evolutionary ways. In this simulation study, we focus on the concurrent evolution of three traits in response to climate change, namely dispersal probability, temperature tolerance (or niche width), and temperature preference (optimal habitat). More specifically, we consider evolutionary responses in host species involved in different types of interaction, that is parasitism or commensalism, and for low or high costs of a temperature tolerance-fertility trade-off (cost of generalization). We find that host species potentially evolve all three traits simultaneously in response to increasing temperature but that the evolutionary response interacts and may be compensatory depending on the conditions. The evolutionary adjustment of temperature preference is slower in the parasitism than in commensalism scenario. Parasitism, in turn, selects for higher temperature tolerance and increased dispersal. High costs for temperature tolerance (i.e. generalization) restrict evolution of tolerance and thus lead to a faster response in temperature preference than that observed under low costs. These results emphasize the possible role of biotic interactions and the importance of 'multidimensional' evolutionary responses to climate change., (© 2015 John Wiley & Sons Ltd.)

Burkholderia pseudomallei (Bp), the causative agent of melioidosis, is unevenly distributed in the complex soil environment. Physicochemical factors in the soil have been reported to affect microbial communities in the soil. The effect of physicochemical factors on the number and diversity of organisms in the soil has not been reported. Twenty-five each B. pseudomallei-positive and -negative soil samples were collected from a melioidosis-endemic area. The amount of Bp in each soil sample was measured by culture and quantitative PCR (qPCR). The following physicochemical properties from each soil sample were measured: pH, total organic carbon (TOC), total nitrogen (TN), carbon to nitrogen ratio (C:N ratio), exchangeable calcium (EC) and extractable iron (EI). All the physico- chemical properties measured were significantly different between the Bp-positive and -negative soil samples. The Bp-positive soil samples had lower C:N ratios and lower EC and a higher EI (p < 0.05) than the Bp-negative samples. The average pH was lower (3.7-5.0) in the Bp-negative samples. Among the Bp-positive soil samples, the EC was negatively correlated with the PCR copy number. The amount of bacteria detected with the qPCR method was higher than with the culture method, suggesting the presence of unculturable forms of bacteria that might re-grow when the environmental conditions was suitable. A total of 117 Bp isolates obtained from the soil samples were classified into 25 groups using BOX-PCR. The genetic diversity of Bp, did not correlate with the physicochemical factors investigated. A suitable pH range and C:N ratio may be important for the presence of Bp. The EI supports the needs and EC probably alters the growth of Bp. The genetic diversity of the bacteria was not influenced by the soil factors investigated in this study. This information shows the environment conducive to the growth of Bp. This gives us information about how to potentially control or decrease Bp in the soil in the future.