Thailand is facing deteriorating water quality in both freshwater and coastal water. Although water pollution comes from both point and non-point sources, the management of non-point source pollution is more challenging due to the difficulty of pinpointing its sources. The Chulabhorn Research Institute (CRI), together with the Thailand Research Fund (TRF), held a one-day workshop, “Thailand 4.0 and the Non-point Source Management Innovation,” on July 25, 2018, at the Century Park Hotel, Bangkok. The opening remarks were delivered by Associate Professor Dr. Chanathip Pharino, the director of the Public Wellbeing Division, TRF, and Professor Dr. Skorn Mongkolsuk, the director of the Laboratory of Biotechnology, CRI. This workshop was part of a TRF-funded research project, “Development of Microbial Source Tracking Methods: A Case Study of Tha Chin River Basin.” Dr. Kwanrawee Sirikanchana, Research Scientist from the Laboratory of Biotechnology, CRI, is the Principal Investigator, and Dr. Pinida Leelapanang Kampangthong, Environmental Specialist from the Freshwater Division, Water Quality Management Bureau, Pollution Control Department, is the Co-Investigator. The one-day workshop facilitated over 50 participants from academia, government agencies, and the private sector. The program began with the presentation, “Non-point Sources: Challenges from Past to Present,” by the research team to raise awareness of the significance and the challenges of non-point sources in Thailand and in other countries. Subsequently, invited experts from government, private,...

Plants have mechanisms to protect themselves from bacterial invasion by sequestering essential metals like iron to create low iron environments. Moreover, plants also generate high levels of reactive oxygen species such as H2O2 and superoxide radicals, which are used as an important initial defense mechanism to inhibit bacterial proliferation during infection. Due to both the necessity of iron for physiological functions and also the toxicity of excess iron resulting from the formation of iron-catalyzed reactive oxygen species, iron homeostasis is tightly regulated in bacteria to ensure survival. The research aims at characterization of the iron-sensing transcriptional regulators, RirA (rhizobial iron regulator) and Irr (iron response regulator) from the phytopathogen Agrobacterium tumefaciens, in order to better understand mechanisms used by bacteria to satisfy their iron demand and prevent iron-induced toxicity. It is also of interest to search for novel physiological roles of RirA and Irr beyond iron regulation and study the interplay between RirA, Irr and other transcriptional regulators to mediate the regulation of gene expression in response to diverse stressful conditions. The research will provide insight into functional roles as well as the impact of these regulators on the survival of A. tumefaciens during plant-pathogen interactions. RirA and Irr are found exclusively in members of alphaproteobacteria, including plant, animal and human pathogens. Therefore, information on the specific regulatory functions of...

The budding yeast Saccharomyces cerevisiae is a powerful model organism for the studies of basic molecular cell biological processes. Most of these basic processes are highly conserved, making the findings in yeast applicable to higher eukaryotes. Here, we exploit the powerful genetic system and numerous genomic tools in yeast to investigate the mechanisms of bacterial toxins in eukaryotic host cells. We also use yeast to perform functional analysis of disease-related mutations in human genes and to investigate antifungal mechanisms of natural products. Characterization of cytotoxic mechanisms of a bacterial genotoxin called Cytolethal Distending Toxin (CDT) from Aggregatibacteractinomycetemcomitans: We use both candidate and genome-wide approaches to investigate the role of host genes in the cytotoxic effect of CdtB, the catalytic subunit with homology to DNase. We conditionally express CdtB from a galactose-inducible plasmid in yeast strains with various gene mutations and in the yeast deletion library. Our findings show that genes involved in homologous recombination repair of DNA double strand breaks are necessary for cell survival upon CdtB intoxication, confirming the role of CdtB as a genotoxin. The genome-wide screens in the yeast deletion library allow us to gain further insights into the mechanisms of CdtB. Identification of novel toxins from an anaerobic pathogenic bacteria: Several pathogenic bacteria translocate effector proteins into host cells as virulence factors, however the genes encoding...

Microbial Source Tracking (MST) methods for the detection of fecal pollution in water:Fecal contamination in water resources has become a problem of i ncreasing concern worldwide. Human pathogens and antibiotic resistant bacteria that are present in fecal material and wastewater can contaminate water and pose a risk to public health. However, current fecal pollution detection methods test for the presence of fecal contamination, but cannot distinguish what type of animal was the ultimate source. MST is an approach to identify fecal sources that contaminate bodies of water through the detection of enteric microorganisms that are specific to a particular host, such as humans, pigs, cows, goats, horses, or groups of similar animals, like ruminants and birds. By identifying the sources of fecal pollution, MST can greatly facilitate the management of polluted bodies of water, thus reducing public health risks and promoting environmental sustainability (Figure 1). The laboratory conducts research involving: the development of methods for measuring MST markers in laboratories and the characterization of different types of MST markers that can be used to identify specific sources of contaminants. These novel methods are then field tested in problem areas around Thailand. This involves the optimization of sampling techniques in the field and assessing the health risks of exposure to contaminated water. Ultimately, the research goals are to expand disciplinary knowledge...

Antimicrobial resistance (AMR) is a global threat to human health and is recognized as a silent pandemic. A recent report in 2019 revealed that deaths associated with bacterial AMR number 4.95 million per year worldwide, including 1.27 million directly attributable to AMR. Since penicillin was discovered, many types of antibiotics have been used to successfully treat infectious diseases. However, these achievements are now at risk mainly because of the overuse or misuse of antimicrobials, leading to the emergence and spread of antibiotic resistant bacteria. AMR bacteria are not only confined to health care settings. They have spread to the environment and have been isolated from human-associated animals, including companion pets, livestock, and farmed fish. Given the increased risks to human health that this spread presents, a multidisciplinary “One-Health approach” is required to solve the problem. In accordance with the mission of the CRI to improve the quality of life through the use of Science and Technology, AMR is one of the primary research focuses of the Laboratory of Biotechnology. To better understand the extent and causes of AMR, the levels of AMR bacteria and their potential drivers are monitored in the environment and food supply. A CRI research team along with collaborators in the United Kingdom (UK) led by the University of Bristol has received a Global Challenge Research Fund...

Nosocomial, or hospital-acquired, infections are an important problem worldwide that affects both developed and developing countries. Nosocomial infections are a major cause of mortality in patients admitted to the hospital and have become a public health problem. Multidrug resistant bacteria are commonly the causative agents of nosocomial infections. These infections are difficult to treat and often require the use of new generation antibiotics, which are highly expensive. The research that is being conducted in the Laboratory of Biotechnology is performed using the bacterial species: Pseudomonas aeruginosa and Stenotrophomonas maltophilia. These pathogens, which are often multidrug resistant, are among the most common causal agents of nosocomial infections in Thailand. Research is being conducted to characterize the novel mechanisms underlying multidrug resistance in these bacteria using genetic engineering techniques to isolate genes that are involved in antibiotic resistance. The results of the research can aid in the identification of new drug targets. The Laboratory of Biotechnology has discovered the novel multidrug efflux transporters, MfsA and MfsQ, from S. maltophilia. MfsA contributes to the transport of several groups of antibiotics, especially those belonging to the fluoroquinolones, out of the bacterial cells, thereby rendering S. maltophilia resistant to multiple antibiotics (Fig. B). MfsQ also functions as an efflux transporter and is involved in bacterial resistance to quaternary ammonium compounds, which are widely used...

The Laboratory of Biotechnology is also interested in genes that contribute to bacterial pathogenesis. During infection, bacteria have to evade and defend against host immune responses. White blood cells, such as macrophages and neutrophils, are the key players in the host innate immune response to infection (Fig. A). These cells generate reactive oxygen and nitrogen species in order to kill invading bacteria. The Laboratory is focused on the study of the genes and enzymes that bacteria use to protect themselves from reactive oxygen species. A more complete understanding of these bacterial defense mechanisms will contribute to one of the laboratory’s main goals, which is to gain insights that can lead to the development of more effective treatments for bacterial infections. One active area of research involves the study of how t-RNA modifications by enzymes such as the methylase, TrmB, increase the translation rate of mRNAs encoding oxidative stress defense proteins such as catalases (Fig. C). The proteins involved in these processes, such as TrmB, are not found in humans and are therefore attractive targets for the development of novel antibacterial therapies. Other lines of enquiry are probing the relationships between oxidative stress and the expression of xenobiotic and antibiotic efflux pumps. Studies of the effect of environmental stresses on bacterial pathogenicity and resistance to antimicrobial compounds are also ongoing. Figure....