Day 1 :
Keynote Forum
Swamy KB
Lincoln University College, Malaysia
Keynote: Life with Down’s syndrome is no more challenging, rather beautiful
Time : 10:00-10:50
Biography:
Swamy K B is presently working as Professor and HOD of Clinical Anatomy, Lincoln University, Malaysia. He has been awarded PhD by Andhra University, India and obtained his Master’s degree (MS in Clinical Anatomy) from Andhra Medical College, India, DMCh (Maternal & Child Health) from IGNOU, New Delhi and his Medical degree (MBBS) in 1976. He has expertise in human genetics, reproductive & developmental anatomy and also in herbal medicine. He has been the Genetic Counselor for many institutions, with prestigious grants (FRGS, URGS) from Malaysian Government. He has been the former Founder Anatomist, Professor and Head of the Department for many medical schools in India as well as in Malaysia. He is an International Editorial Board Member for many reputed journals like Anatomical Society of India (ASI). Recently he has been unanimously elected as an Executive Board Member for ASI and Editor for many journals like Novel Techniques in Nutrition and Food Science, Annals of Anatomy & Physiology, Journal Anatomical Society of India (JASI), etc., and also Manuscript Reviewer for journals like Food & Chemical Toxicology (Elsevier), Novel Techniques in Nutrition and Food Science, etc.
Abstract:
When many people hear the words “Down syndrome” they picture a significantly disabled person with a poor quality of life. Advances in medicine mean that stereotype no longer applies. Advocates for people with Down syndrome are trying to educate the public on their abilities. The lives of the 250,000 Americans with Down syndrome today are radically different than a generation ago, says Brian Skotko, co-director of the Down syndrome program at Massachusetts General Hospital. Medical advances and educational supports have led to increased life expectancy and better quality of life for those with Down syndrome. A survey done by Skotko showed that 99% of those with Down syndrome were happy with their lives. Additionally, the survey found that 88% of siblings felt that having a person with Down syndrome as their brother or sister had made them better people. Down syndrome was first studied and described by a doctor named John Langdon Down. In every cell in the human body there is a nucleus, where genetic material is stored in genes. Genes carry the codes responsible for all of our inherited traits and are grouped along rod-like structures called chromosomes. Typically, the nucleus of each cell contains 23 pairs of chromosomes, half of which are inherited from each parent. Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21. This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome. A few of the common physical traits of Down syndrome are low muscle tone, small stature, an upward slant to the eyes and a single deep crease across the center of the palm – although each person with Down syndrome is a unique individual and may possess these characteristics to different degrees, or not at all. According to the Centers for Disease Control and Prevention, approximately one in every 700 babies in the United States is born with Down syndrome, making Down syndrome the most common chromosomal condition. About 6,000 babies with Down syndrome are born in the United States each year. It can be concluded that although those with Down syndrome still face significant medical and educational challenges, it is important that the public perception of these individuals accurately reflect their abilities.
Keynote Forum
Regina Mary R
Auxilium College, India
Keynote: Microbial bioactive compound for food preservation with antioxidant
Time : 10:50-11:40
Biography:
Regina Mary R has her passion in educating and empowering the rural young women. She has her expertise in the field of development of bioactive compounds from microorganism for the biomedical application. Her contribution towards preparation of surface modification and bioactive compound conjugated nanoparticle for the treatment of pathogens from water and food system with a molecular mechanistic explanation. She has built this model after years of experience in research, evaluation, teaching and administration both in education institutions. She also has her unique contribution in the field of infection in gastrointestinal track and respiratory track due to the foodborne pathogens and its treatment by probiotics for health benefits of young women.
Abstract:
Food safety is a global issue with significant implications for human health. The World Health Organization reports that, annually, unsafe food results in the illnesses of at least 2 billion people worldwide and can be deadly. Some countries have made great progress in controlling foodborne diseases, but the number of those affected by foodborne diseases is growing globally (WHO, 2004). Foodborne disease is a global issue with significant impact on human health. With the growing consumer demand for natural preservatives to replace chemical compounds, plant and microbial antimicrobial compounds must be thoroughly investigated for their potential to serve as bio-preservatives. Our research focus the microbial-derived products as antimicrobial agents for use in food preservation and to control foodborne pathogens in foods. Structure, modes of action, stability, and resistance to these plant compounds will be discussed as well as their application in food industries and possible technologies by which they can be delivered. Benefits as well as challenges, such as the need for further research for implementation and governmental regulation, will be highlighted. Thermal processing is a common method of destroying vegetative microorganisms to ensure food safety, but this technique may cause undesirable nutritional and quality effects [3]. Preservatives are commonly used to reduce the risk of foodborne illnesses. Increasing regulatory restrictions and consumer negative response to chemical compounds and to the use of antibiotics in agriculture have contributed to the pressure for the development of alternative compounds for use as antimicrobial agents.
Antimicrobial agents have been predominantly isolated from bacteria and fungi and either produced through fermentation. Worldwide, spending on anti-infective agents has increased in recent years due to the limited effective lifespan of antibiotics as new resistant microbes emerge. New sources, including microbial bioactive molecules, must be thoroughly investigated for identification of novel antimicrobial compounds. Prodigiosin is a natural red colored bacterial secondary metabolite, widely used in pharmacological and biological applications. This investigation focused on nutraceutical and food functionalization potential of natural colorant PG. The antioxidant potential of PG was examined by DPPH and ABTS radical scavenging method. The bactericidal efficiency of PG was analyzed against six foodborne pathogens. The food Shelf life extant ability of PG was analyzed using meat extract powder as a model food material. The PG (70.19g/kg) was biosynthesized from Serratia marcescens by solid state fermentation. The scavenging activity of PG were calculated to be 99% and 99.9% were DPPH and ABTS respectively. The bactericidal efficiency of PG against the selected foodborne pathogens exhibited significant inhibition on growth than the synthetic colorant and the shelf life of the food was extended in the presence of PG containing food model. Hence, the PG may be used as food colorant and thus significantly reduce the addition of synthetic colorant in food processing industry. This study will bring an innovative approach on food additive for safe and sustainable food process. Because of variation in stability and efficacy to various food processing parameters and food systems, it is critical that natural prodigiosin be selected and delivered so that they are active against potential pathogens in particular food and are stable throughout the food’s shelf life. Effects of natural prodigiosin in combination with other compounds or techniques must be more thoroughly investigated. Prodigiosin is active against Gram-positive bacteria and fungi. Given the consumer demand for more natural products and the growing need for alternative preservatives to ensure food safety, it is imperative that natural bioactive prodigiosin be fully assessed for their feasibility for food application. This new field of research has great potential for more evaluation to meet regulatory requirements and to fully elucidate the possibility of employing antimicrobials from the extensive source of microbial worldwide.
- Toxicology | Toxicology and Risk Assessment | Experimental and Toxicologic Pathology | Forensic Toxicology | Analytical Toxicology | Pharmacological Testing
Session Introduction
Brian Waters
Fukuoka University, Japan
Title: A comprehensive method for the screening of drugs in severely decomposed human tissues by fast gas chromatography/tandem mass spectroscopy (Fast GC-MS/MS)
Biography:
Brian Waters has received his Master of Science degree in Criminalistics from California State University, Los Angeles, USA. After working as a Criminalist for the County of Los Angeles, Department of Coroner/Medical Examiner for almost 8 years, he has joined as an Assistant Professor in the Department of Forensic Medicine at Fukuoka University in Japan. His specialty is postmortem forensic toxicology and he has published academic papers on fast gas chromatography-mass spectrometry, the analysis of novel psychoactive compounds, preparation methods for postmortem samples and the analysis of volatile hydrocarbons in blood.
Abstract:
Statement of the Problem: Drug screening is an important reference in forensic autopsy investigations. In postmortem toxicology, often the samples provided for analysis are in a severe state of putrefaction or decomposition. The presence of breakdown products such as lipids and amino acids make extraction of the compounds of interest difficult. Also, developing an analytical method capable of detecting trace levels of analytes from the interfering substances present in these complex matrices adds to the challenges.
Methodology & Theoretical Orientation: For this study, putrefied and decomposing tissue samples from actual cases autopsied at our department were analyzed. Human tissue specimens consisted of liver, kidney, spleen, lung, muscle and brain, if available. The drugs detected from these specimens included phenobarbital, chlorpromazine, promethazine, aripiprazole, amlodipine, telmisartan, rosvastatine, chlorpheniramine, etizolam and zolpidem. Specimens of 0.3 g were treated with urease, acidified or alkalized and extracted with acetonitrile. Lipid-removal and solid-phase extraction cartridges were employed while carefully monitoring the pH of samples to ensure the adequate removal of interfering substances. The extracts were evaporated and reconstituted in n-propyl acetate:methanol (1:1) for fast GC-MS/MS analysis.
Findings: The developed method was successful in clearly identifying drugs from putrefied specimens. The use of tandem mass spectrometry helped to reduce the influence of background noise and interfering substances.
Conclusion & Significance: Putrefied specimens are often the only remaining samples left from severely decomposed cadavers. The combination of a robust preparation method and analysis with fast GC-MS/MS could aid the forensic medicine and toxicology communities in elucidating important information from these often-overlooked biological matrices.
Fabio de Oliveira
Federal University of Uberlandia, Brazil
Title: Snake venom peptides: Potential therapeutic agents in thrombotic diseases
Biography:
Fabio de Oliveira has completed his PhD in 2001 from National University of Brasília in Brazil. He was the Director of Innovation and Transfer of Technology of the Federal University of Uberlandia. Currently he is the Professor of the postgraduate program in Genetic and Biochemistry and in Cellular and Structural Biology of the same university. He has experience in the area of biochemistry, biophysics and biotechnology with emphasis in isolation and characterization of pharmacologically active principles present in venom of Brazilian snakes.
Abstract:
The snake venoms are constituted of a true biochemical arsenal, consisting of several proteins and peptides with activities that have aroused the curiosity of researchers for centuries, in an attempt to understand its systemic action in order to get pharmacological applications. A number of snake venom proteins that interfere on platelet aggregation have been isolated from these venoms. However, there are no reports in the literature of small peptides interfering in aggregation. In the present work, we identify and characterize, for the first time, a heptapeptide (BaltPAi: platelet aggregation inhibitor from B. alternatus snake venom) and a decapeptide (BmooPAF: platelet-activating factor from B. moojeni snake venom), which potentially inhibits and induces the platelet aggregation, respectively. BmooPAi shows a rather specific inhibitory effect on collagen-induced platelet aggregation in human platelet-rich plasma, whereas it has little or no effect on platelet aggregation induced by adenosine diphosphate. The results presented here suggest that the BaltPAi consists of an amino acid sequence present in the C-terminal region of snake venom phospholipase A2 enzymes. This sequence would be responsible for the inhibition of platelet aggregation as well as for the cytotoxicity effects of tumor cells caused by these enzymes. Assays with monoclonal antibodies (anti-integrin α2b and anti-GP1BA) show a significant inhibitory effect on BmooPAF-induced platelet aggregation. On the other hand, anti-GPVI antibody shows no effect on platelet function. These findings, associated with molecular docking, indicate that BmooPAF induces platelet aggregation via binding to the GPIbα platelet receptor leading to αIIbβ3 integrin activation. These toxins could be of medical interest as tools for the development of novel therapeutic agents for the prevention and treatment of thrombotic disorders.
Mahmoud I Shoulkamy
Minia University, Egypt
Title: Ionizing radiation induces developmental abnormalities but not lethality of sea urchin embryos
Biography:
Mahmoud Ibrahim Shoulkamy has his expertise in DNA damage response to environmental and anticancer agents and risk sciences of radiation and chemicals. He has received his Doctoral degree from Graduate School of Science, Hiroshima University, Japan in 2013 in the field of DNA damage and its repair mechanisms. In 2013, he was appointed as Assistant Professor (special appointment) in Graduate School of Science, Hiroshima University, Japan until 2016 and currently he is working as Assistant Professor in Zoology Department, Faculty of Science, Minia University, Egypt.
Abstract:
The Fukushima nuclear power plant accident occurred in japan on March 2011, initiated by tsunami following a great earthquake cause the discharged of radioactive materials into the environment. This accident received considerable attention for their effect on marine ecosystems. Sea urchins are model organisms in developmental biology research and their embryos are sensitive to toxins and used to study the developmental and cytological effects of anthropogenic pollutants and environmental stressors. In the present study sea urchin embryos were used as a model system to assess the effect of ionizing radiation on the viability and early development of marine invertebrate animals. Sea urchin embryos were culture in filtered sea water at 16 °C at the different developmental stages were irradiated with X-rays (70 kV, 0.2 mm Al filter, dose rate=1.46 Gy/min) and further incubated in filtered sea water at 16 °C. Irradiation of embryos at the different stages of development (32-cell, mid-gastrula and early Pluteus larva) at doses up to 30 Gy did not reduce the viability of embryos. However, irradiated embryos exhibited dose-dependent developmental abnormalities. Typical abnormalities observed for gastrula embryos were delayed development and a reduced number of primary and secondary mesenchyme cells and those for mid Pluteus larva were delayed development, skeletal abnormalities, separated body rod tips and fused arms. Interestingly, the frequency of X-rays induced abnormalities increases when embryos were irradiated before mid-blastula transition (MBT) and starts to decrease thereafter. The analysis of apoptosis of X-ray irradiated embryos resulted in the absence of apoptotic response when embryos were irradiated before MBT. However, there is immediate apoptotic response was observed when embryos were irradiated after MBT.
Ahmad Khalil
Yarmouk University, Jordan
Title: In vivo characterization of the biochemical and histological changes induced by the stonefish (Synanceia verrucosa)venom in rats
Biography:
Ahmad Khalil has received his PhD in Cyto-genetics from The Ohio State University, USA in 1987. He chaired the Department of Biological Sciences at Yarmouk University, Jordan (2001-2003). He has founded Biotechnology MSc Program in 2003. In Arabic, he authored a book in radiation biology, a unit in molecular biology, a chapter in genetics. He has written 35 single-authored scientific articles of general interest. He has published 45 research papers in peer-reviewed international journals. He has received several awards and fellowships and is active Reviewer and Member in Editorial Board of several local, regional and international journals.
Abstract:
Statement of the Problem: The stonefish (Synanceia verrucosa) is one of the most dangerous venomous fishes ever known. Stonefish venom may be life-threatening to humans, envenomation can be quite hazardous, provoking extreme pain and imposing significant socioeconomic costs, as the victims may require days to weeks to recover from their injuries. Very little research has been undertaken on marine creatures, particularly venomous fish. The purpose of this study is to evaluate the toxicity of the stonefish (S. verrucosa) venom as well as biochemical and histological changes in a rat model.
Methodology: Fish samples were collected by SCUBA diving from the northern sites of the Red Sea (Gulf of Aqaba/Jordan). The crude venom was extracted from the spines and biochemical and histopathological changes induced by intramuscular injection of the sub lethal dose of the venom of were examined in Sprague-Dawley rats.
Findings: The 24h LD50 of the venom was estimated to be 38 μg venom/kg body weight. The levels of the serum biochemical markers; alanine transaminase, lactate dehydrogenase and creatine kinase increased 6 hours after administration and remained significantly high till 24 hours. Envenomed animals exhibited symptoms like convulsions, muscular dis-coordination and paralysis, urination and respiratory failure. Envenomation caused massive damage to liver tissues. Similarly, extended treatment of rats was manifested as interstitial hemorrhage and widening of kidney tubules. Furthermore, the venom caused neuro-pathological alterations such as spongiosis of brain tissue and had myotoxic effect on cardiac tissues.
Conclusion & Significance: The S. verrucosa venom contains edema-causing factors and is hepatotoxic, nephrotoxic, myotoxic and neurotoxic to the test rat model. The findings may encourage the health care industry to develop an indigenous anti-venom related valuable pharmaceutical product.
Brian Waters
Fukuoka University, Japan
Title: Tissue distribution of suvorexant in three postmortem cases
Biography:
Brian Waters received his Masters of Science degree in Criminalistics from California State University, Los Angeles, USA. After working as a Criminalist for the County of Los Angeles, Department of Coroner/Medical Examiner for almost eight years, he accepted a position as an Assistant Professor in the Department of Forensic Medicine at Fukuoka University in Japan. His specialty is postmortem forensic toxicology, and he has published academic papers on fast gas chromatography-mass spectrometry, the analysis of novel psychoactive compounds, preparation methods for postmortem samples, and the analysis of volatile hydrocarbons in blood.
Abstract:
Statement of the Problem: Suvorexant (Belsomra®) is a relatively new insomnia medication that has been available in the US and Japan since 2014. It is a dual orexin receptor antagonist that promotes sleep by inhibiting the binding of orexin neurons to the OX1R and OX2R receptors. In this report, we describe the detection and quantitation of suvorexant from the postmortem specimens of three recent autopsy cases handled by our department.
Methodology & Theoretical Orientation: Suvorexant was identified by fast GC-MS during routine screening (Fig. 1) and quantitated by a fully validated LC-MS/MS method. Quantitation was achieved by positive electrospray ionization in the selected reaction monitoring mode. Monitored transitions were m/z 451 > 186 for quantitation and m/z 451 > 104 for qualification. Diazepam-d5 was used as an internal standard.
Findings: Suvorexant was detected and quantitated in the body fluids and tissues of three autopsy cases. The specimens included cardiac blood, peripheral blood, urine, liver, kidney, spleen, pancreas, lung, muscle, fat, and cerebrospinal fluid. Tissue distribution across the three cases will be presented and discussed.
Conclusion & Significance: The use of suvorexant as an insomnia medication has recently increased around the world. To our knowledge this is the first instance of suvorexant being quantitated from actual autopsy cases. It is possible the presence of this medication in clinical and forensic samples has been missed due to its high boiling point and thus late elution in gas chromatography. We were able to detect suvorexant in three cases by using fast GC-MS, which significantly reduced its retention time. It is likely that this compound will be encountered more often by the forensic and clinical toxicology communities going forward.
Sankaran P K
Saveetha Medical College and Hospital, India
Title: Protective effects of vitamins on Diclofenac induced hepatotoxicity in adult male wistar albino rats
Biography:
Dr P K Sankaran is working as Associate Professor in Dept of Anatomy, Saveetha Medical College, Chennai, India. He has been working in developing pain models related to trigeminal neuralgia and its treatment module in animals.
Abstract:
Introduction: Drug induced liver injury (DILI) possesses a major clinical problem and has become leading cause of acute liver failure and transplantation. Overstressed liver compromises its detoxification role which may expose it to a variety of diseases and disorders. Diclofenac sodium is a phenyl acetic acid derivative, a widely used NSAID for treatment of inflammatory conditions like osteoarthritis, rheumatoid arthritis, polymyositis, dermatomyositis, dental pain, spondyloarthritis, acute migraine, gout attacks, and pain management in gall and renal stones. Though the exact mechanism by with diclofenac injuries liver is not understood, some studies explain the toxicity by affecting cytochrome P 450 leading to production of active metabolites. This study was done to show the changes in the liver following diclofenac treatment and to study the heaptoprotective effects of vitamin A and C in diclofenac treated rats.
Methodology: Rats were divided into four groups each 6 rats. Group 1: (n=6) control rats, Group 2: (n=6) rats treated with diclofenac at dose of 75 mg/kg IP for seven days, Group 3: (n=6) rats treated with vitamin A at dose of 10 mcg/kg orally followed by diclofenac at 75 mg/kg IP 2 hours later for seven days for seven days, Group 4: (n=6) rats treated with vitamin c at dose of 200mg/kg orally followed by diclofenac at 75mg/kg IP 2 hours later for seven days.
Findings: Following diclofenac treatment there the liver function test was elevated in diclofenac treated group which was significantly reduced by the vitamin C compared to vitamin A. The liver acinus showed centriacinar necrosis of hepatocytes after seven days of diclofenac treatment, which was prevented by administration of vitamin A and C. The hepatocyte necrosis was well prevented by administering vitamin C. So the hepatoprotective effects of vitamin C were better compared to vitamin A following treatment with NSAID. So it may be necessary to administer vitamin C in patients treated with diclofenac.
Karthikeyan G
Saveetha Medical College & Hospital, India
Title: A study on exploring the toxicity of alcohol in the oral mucosa of alcoholics
Biography:
Karthikeyan G is an Assistant Professor of Department of Anatomy at Saveetha Medical College & Hospital, India. He has upcoming research projects which are granted by Indian Council of Medical Research.
Abstract:
Background: Oral cancer is the most common malignancy in nearly half of Indian population. The main causes of oral carcinoma are tobacco, alcohol, poor diet and infective agents. These agents damage the chromosomes to form several secondary nuclei known as micronuclei. This study identifies the occurrence of micronuclei and also evaluates the frequency of micronuclei in stained smears of oral exfoliative cells from healthy subjects and alcoholic subjects
Materials and methods: A total number of 60 alcoholic subjects were referred to the Department of Anatomy, Saveetha Medical College for micronucleus assay from the Dept of Dentistry. Equal numbers of controls were included with normal looking oral cavities.
Results: Out of 60 alcoholic subjects 43 showed presence of micronuclei and out of 60 control subjects, only 6 showed micronuclei. With these observations alcohol is one of the factors predisposing to oral carcinoma.
Conclusion: It is evident from our present study, it is clear that in alcohol consumption, the buccal mucosa, which are at high risk for development of oral cancer, show an increase in micronuclear frequencies.
Aied Mohammed Alabsi
University of Malaya, Malaysia
Title: Chemo-preventive potential of Ficus deltoidea on oral cancer cells in vivo
Biography:
Aied Mohammed Alabsi has received his Bachelor of Biomedical Sciences from the University of Sana’a, Yemen in 1996 and joined the Kuwait University Hospital, Sana’a University, Yemen after graduation. He began his Master and PhD research at University Putra Malaysia and received his PhD in Cell and Molecular Biology in 2008. After obtaining his PhD, he worked as a Post-doctorate at University Putra Malaysia in 2008. He was appointed as a Senior Lecturer in 2009 and Associate Professor in Oral Biology and Biomedical Sciences in 2014. Currently, he is an Associate Professor at Faculty of Dentistry, University of Malaya. He had published more than 30 papers in his main area of research being molecular biology, cancer and stem cells. He has a special interest in pre-clinical assessment of mesenchymal stem cells from various sources and in all aspects of regenerative dentistry research.
Abstract:
Oral squamous cell carcinoma (OSCC) is the sixth most common malignancy worldwide and the 5-year survival rate of around 50% has not improved significantly during the past 30 years. New approaches to treat the disease are urgently needed. Chemotherapy in combination with anticancer agents derived from natural products offer a promising new approach in an attempt to improve patient prognosis. Ficus deltoidea is a common medicinal plant traditionally used in Southeast Asia countries including Malaysia. Previous studies demonstrated that Ficus deltoidea has a wide variety of medical importance including antibacterial, antithrombotic and anticancer. This study was conducted to determine the chemo-preventive effects of Ficus deltoidea on OSCC cells by using rat animal model. The powder of Ficus deltoidea in this study was extracted with methanol using macerated methods. The evaluation the Ficus deltoidea chemo-preventive activity in vivo was carried out using 4NQO-animal model. 35 SD rats were divided randomly into 5 groups of seven rats per each. Four groups were supplied with 4NQO (20 ppm) in their drinking water for 8 weeks. Ficus deltoidea methanol extract groups were administered orally to the rats starting one week before exposure to the carcinogen (4NQO) until one week after the stop of the carcinogen exposure (total of 10 consecutive weeks of administration). The results obtained showed that no significant decrease in mean body weight gain was seen in Ficus deltoidea methanol extract especially at dose 1000 mg/kg. The incidence of SCC induced by 4NQO in rats receiving Ficus deltoidea methanol extract at 100, 500 and 1000 mg/kg was 35.9%, 25.6% and 10.3%, respectively and developed smaller tumors (tumor volume) than vehicle and induced cancer groups. The results of this study indicate that specific extracts of Ficus deltoidea have promise to be developed as novel therapeutic agents for the treatment of OSCC.
Jason Paxman
La Trobe Institute for Molecular Science, Australia
Title: Using protein crystallography to disarm bacterial pathogens
Biography:
Jason Paxman is a senior postdoctoral researcher within the group led by Dr Begoña Heras within the Department of Biochemistry and Genetics at the La Trobe Institute for Molecular Science, Melbourne Australia. He has a strong interest in deciphering the mechanisms of action of bacterial virulence factors using X-ray crystallography. During his PhD at Monash University Australia he revealed for the first time how DsbA, a key bacterial virulence regulator, binds and folds a plethora of bacterial virulence factors. Past appointments include the Commonwealth Scientific and Industrial Research Organisation, The University of Melbourne and the Australian Synchrotron. Career highlights include developing anti-anthrax agents for the U.S. Department of Defence and being awarded an Australian Synchrotron Research Fellowship. His current work includes determining the mechanisms of action for one of the largest groups of bacterial virulence factors, the autotransporters.
Abstract:
Emerging bacterial resistance to antibiotics was recently described by the World Health Organisation as a ‘global health emergency’. The development of new types of antibiotics is clearly not keeping pace with bacterial resistance. If we are to solve this problem we need alternative ways of thinking. We still know so little with regard to how bacteria use protein virulence factors to colonise, infect and cause diseases in hosts at the molecular level, and this information is pivotal towards developing new anti-microbials. My research involves understanding the molecular mechanisms of bacterial virulence factors and their regulators along with their roles in bacterial pathogenesis. I use various forms of recombinant protein expression, production and purification to produce these virulence factors for protein crystallisation. Utilising the Australian Synchrotron I then solve the structures of these virulence factors, and in combination with both biophysical and biochemical assays, I determine their mechanisms of action and then how to inhibit their functions. Autotransporter proteins are the largest group of outer membrane and secreted virulence factors from medically important bacterial pathogens. We were the first to reveal how autotransporter adhesins from pathogenic E. coli such as Antigen 43 promote biofilm formation while others such as UpaB can faciliate colonisation of human epithelium. Using this knowledge we have since developed inhibitors that can bind these adhesins to block their pathogenic phenotypes. Bacterial disulfide oxidoreductases are critical for the stable folding of many virulence factors. In this area we have well established research of targeting widespread disulfide oxidoreductases to inhibit the production of functional virulence factors. Overall, our research is leading the way towards developing anti-bacterial therapeutics that target the virulence factors themselves and so offer reduced emergence of bacterial resistance.