Day 3 :
- Track 8: Animal Bacterial Diseases
Track 9: Advances in Antimicrobials, Vaccines and Therapeutics
Track 10: Diagnostic Pathology of Infectious Disease
Location: Melia Meeting 1 & 2
Chair
B Y Chin
International Medical University, Malaysia
Co-Chair
Tony Velkov
Monash University, Australia
Session Introduction
B Y Chin
International Medical University, Malaysia
Title: Carbon monoxide: A poison to microbes
Time : 10:00-10:20
Biography:
B Y Chin received her degree in Physiology and Toxicological Sciences from the Department of Environmental Health Sciences at Johns Hopkins University, Baltimore, Maryland. She continued her research at the Department of Surgery at Beth Israel Deaconess Medical Center in Boston, Massachusetts after completing her Post-doctoral fellowship at Pacific Northwest National Laboratory, US, Department of energy in Richland, Washington. She also had a joint Faculty appointment at Harvard Medical School since 2006. She has published over 33 peer review journal articles and is an active member on 3 editorial boards. Currently, she is a Professor of Medical Sciences and Associate Dean of Health Sciences at the International Medical University.
Abstract:
Inflammation and immunity result in a wide range of disease processes, including chronic obstructive pulmonary disease, ischemia-reperfusion injury, atherosclerosis, vascular thrombosis and sepsis. Heme oxygenase-1 (HO-1) is a key enzyme that is indispensable for the temporal and spatial regulation of host response and together with its essential metabolite carbon monoxide (CO), is crucial for maintaining homeostasis, inhibition of inflammation and the preservation of function and life. Of the numerous physiologic effects observed with CO, in the last 5 years, it has become apparent that CO has been ascribed an additional novel, yet innate role as a “bactericidal agent”. Its role in the maintenance of homeostasis remains intact, however, the designation necessitates the paradoxical induction of the inflammatory response and binding to hemo-proteins in order to restore physiological balance and sustain life. In this presentation we will review and discuss recent reports that have propelled and possible establish the paradoxical use of CO, once viewed as a toxic molecule, now as a host defense molecule agent against pathogens.
Tony Velkov
Monash University, Australia
Title: Development of novel antimicrobial lipopeptides against MDR Gram-negative ‘superbugs’
Time : 09:20-09:40
Biography:
Dr Tony Velkov completed PhD in 2000 from Monash University. His anti-infective discovery research is at the leading edge globally. He was awarded a NHMRC Research Fellowships in 2006, 2011 and 2014. The quality and impact of his independent research was recognized by the NHMRC with an Excellence Award in 2011. He has published over 50 papers in high-caliber journals, 3 book chapters and 15 conference presentations. The dynamic team he leads consists of 3 postdocs, 3 RAs and 9 PhD students. Over the last 6 years, he has obtained >$9M funding from the NIH, NHMRC and foundations.
Abstract:
The octapeptins are a family of naturally occurring cyclic lipopeptide antibiotics with a broad antimicrobial spectrum against multidrug-resistant (MDR) Gram-negative and Gram-positive ‘superbugs’. Octapeptins were discovered over 30 years ago, consequently there is limited information on their chemical biology and structure-activity-relationships (SAR). Accordingly, the broad aim of our study is to explore the chemical biology of the octapeptins through a SAR approach. Synthetic chemistry will be employed to generate a large series of novel analogs that will be evaluated against the biological systems the octapeptins are known to modulate. The best approach to achieve this is through the substitution of existing amino acids with novel derivatives rather than chemical modification of the side-chain functionalities. This can only be achieved through a ‘total synthesis’ approach, which is a particularly challenging task considering the complex chemical structure of the octapeptins. To the best of our knowledge, we are the first group to have developed an efficient routine ‘total synthesis’ of octapeptins on a scale that would allow for mechanistic investigations of antibacterial activity and resistance. For the first time our novel approach will interface the chemistry and biology of these important antibiotic compounds to investigate the underlying SAR with the purpose of creating new functions. More specifically the ultimate aim is to med-chem out liabilities such as nephrotoxicity whilst concomitantly improving the antimicrobial activity and spectrum, thereby creating the foundations for a new generation of safer and more efficacious antibiotics.
C. Diaz
Fundación MEDINA, Spain
Title: New Antibacterial Agents against Gram-negative Pathogens from a Fundacion MEDINA’s Microbial Natural Products Collection Screening
Time : 09:40-10:00
Biography:
Caridad Díaz completed his degree in Biochemist and Biology at the Granada University and she has worked as researcher in the screening and target validation department from Fundación MEDINA since 2010. She has published more than 5 papers in reputed journals and has presented more than 10 communications in International congress.
Abstract:
New antibacterial agents for treating Gram-negative bacteria are one of the main unmet medical needs because bacterial resistance represents a major issue for all classes of antibiotics. In this regard and considering that the majority of the antibiotics in the marketplace or clinical development derive from screening approaches with natural products, we developed a high throughput discovery program with the Fundación MEDINA’s microbial natural products collection. This collection contains more than 131,000 extracts and covers an uncommonly unexplored broad chemical space resulting from a variety of fermentation products. From that screening, several new compounds have been identified with activity against Gram-negative pathogens possessing a previously unreported chemical scaffold. They may represent a starting point for the development of a novel treatment of infections. These new compounds (MDN-057, MDN-0114, MDN-0116 and MDN-0119), with unprecedented structures, with molecular weights ranging from 282 to 544 Da and with MICs (Minimal Inhibitory Concentration) in the 40-128 µg/ml range against Acinetobacter baumannii and other resistant clinical strains, are described in this work
Promod Mehta
Maharshi Dayanand University, India
Title: Comparing several gene targets of Mycobacterium tuberculosis for designing multiplex-PCR: It’s implications for diagnosis of extra pulmonary tuberculosis
Time : 09:00-09:20
Biography:
Promod Mehta presently as Director at Centre for Biotechnology, Maharshi Dayanand University, India
Abstract:
Diagnosis of extra pulmonary tuberculosis (EPTB) exhibits true challenges due to paucibacillary nature of specimens. An early diagnosis of EPTB is needed to initiate anti-tubercular therapy to avoid unnecessary morbidity and mortality. During the last decade, Polymerase Chain Reaction (PCR) assays have emerged important tools in diagnosing EPTB specimens. Many studies have shown the inability of a single gene target to detect M. tuberculosis with certainty in biological specimens. A careful selection of gene targets is imperative for designing a Multiplex-Polymerase Chain Reaction (M-PCR) assay. We compared various gene targets of Mycobacterium tuberculosis that is IS6110, genes encoding MPB-64 (mpb64; Rv1980c), 38 kDa (pstS1; Rv0934), 65 kDa (hsp65; Rv0440), 30 kDa (fbpB; Rv1886c), ESAT-6 (esat6; Rv3875) and CFP-10 (cfp10; Rv3874) proteins and devR (Rv3133c) by PCR assays on the same 105 EPTB specimens. The mpb64 showed the highest sensitivity followed by IS6110, hsp65, 38 kDa, 30 kDa, esat6, cfp10 and devR. This study showed the authenticity of mpb64+IS6110 in designing an M-PCR assay as high sensitivity (96% in confirmed EPTB cases and 89% in clinically suspected EPTB cases) and specificity (100%) was observed using clinical diagnosis as the gold standard. These results along with the clinical findings and histopathological/cytological observations may help for an early diagnosis of EPTB. This simple and cost-effective test may also be a better alternative than rpoB (encoding RNA β polymerase subunit) based Xpert assay especially in resource-poor settings.
Gamal Wareth
Friedrich-Loeffler-Institut, Germany
Title: Investigation and molecular typing of Brucella isolated from dairy cattle herd immunized with Brucella abortus RB51 vaccine in Egypt
Time : 10:20-10:40
Biography:
Gamal Wareth has obtained his Bachelor degree (BVSc) from faculty of Veterinary Medicine, Assuit University, Egypt in 2002. He completed his Master degree in Veterinary Pathology in 2009 at Benha University, Egypt. Then he enrolled for DVM in Free University of Berlin in collaboration with Friedrich-Loeffler-Institut (FLI), Germany. He is currently works in NRL of brucellosis at Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses in Jena, Germany. The main areas of his interest are development of diagnostic products; proteomics, epidemiology, molecular epidemiology and microbiology of pathogen level 3 agents (Brucella spp., Francisella tularensis, Burkholderia mallei/pseudomallei, Bacillus anthracis, Yersinia pestis).
Abstract:
Brucellosis is still a common in capacitating zoonoses that affecting wide range of domesticated and wild animals as well as humans. Brucella was firstly described by Sir David Bruce in 1887 in human. Fifty two years later (1939), the disease was reported in Egypt for the first time in a scientific report, however the doubt still exist if, whether the disease is endemic in Egypt since thousands of years. Since then the disease remained endemic nationwide and affecting all livestock animals. In Egypt, brucellosis control programs for bovines are based on a test and slaughter policy as well as vaccination. Recently, Mass vaccination with attenuated B. abortus RB51 has been approved nationwide; however some may lead to abortion in pregnant females. The present study was carried out in supposed Brucella-free dairy cow farm in Egypt to investigate a numerous occurrence of abortions occurred after immunization with B. abortus strain RB51. Among pregnant vaccinated cows, 10% aborted three months post vaccinations. All aborted cows show positive reaction with Rose Bengal Test (RBT) and Complement Fixation Test (CFT). B. abortus biovar one was isolated from four aborted fetuses. Conventional biochemical analysis revealed two B. abortus smooth type and two rough types. The use of the Bruce ladder PCR provided clear differentiation to the field strain and excludes the RB51 vaccine strain. Genotyping analysis of isolates by Multiple Loci VNTR Analysis (MLVA-16) cleared that there are two different isolates in the herd with low genetic diversity. Isolated B. abortus are located in a different cluster from the RB51 vaccinal strains which used in immunization of the herd. In Conclusion: B. abortus bv1 is the source of outbreak but not the vaccine. RB51 vaccine would only reduce the number of abortions caused by field strains but offer no protection from infection. The most likely source of infection appears to be the uncontrolled introduction of the agent via vectors or latent carrier. Eradication of brucellosis is a multidirectional process required combination between ordinary control program and high biosecurity level in the farms.
Memon Z
Liaquat University of Medical & Health Sciences, Pakistan
Title: Serum trace elements in active pulmonary tuberculosis by atomic absorption spectrophotometer
Time : 10:55-11:15
Biography:
Zainab Manzoor Memon Ph.D. Research Scholar in Biochemistry. Presently she is working at Liaquat University of Medical & Health Sciences, Jamshoro, Pakistan. She has eight international research publications and presented her research work at national and international conferences. She has attended many academic workshops, symposium and has three years research experience. She has expertise on bio analytical techniques such as AAS, Spectrophotometer, AAA, Ultra Centrifuge Machine, HPLC, Microlab 300 & Chemistry Analyzer. She also has command on statistical software including SPSS and Minitab.
Abstract:
Background: Tuberculosis (TB) is a curable disease though it is still remains a major public health problem worldwide especially in developing countries. TB ranks as the second leading cause of death throughout the world. Pakistan ranked as fourth in the midst of 22 elevated challenging tuberculosis nations. Trace elements have involved in many biochemical and physiological functions. Poor concentration of trace elements has been resulting clinical outcome. Objectives: The objective of study was to find out the alteration in serum trace elements levels in active pulmonary tuberculosis patients and was compared it with normal healthy volunteers with no sign and symptoms of TB. Method: A total of 248 active pulmonary tuberculosis patients were selected from Liaquat University of Medical & Health Sciences, Jamshoro, Sindh, Pakistan, Liaquat University Hospital, Hyderabad, Sindh, Pakistan, Rajputana Hospital, Hyderabad, Sindh, Pakistan and Institute of Chest Diseases, kotri, Sindh, Pakistan. The subjects were recruited from both genders with same age group 20-70 of years. Blood samples of active pulmonary tuberculosis patients with sputum smear positive were collected and were compared with healthy control subjects without symptoms of pulmonary tuberculosis. Approval was taken from all hospitals. Informed consent was also taken from each patients and healthy participants. Serum trace element analysis was carried out by flame atomic absorption spectrophotometer (FAAS). Results: Among 248 active pulmonary tuberculosis patients, 104 (42%) was male patients while 144 (58%) was female subjects respectively. The interpretation of outcome was made on the basis of reference ranges. In our study we were found that the mean serum zinc, iron and magnesium were significantly low in active pulmonary tuberculosis patients (58.1 mg/dl), (34.2 mg/dl) and (0.6 mg/dl). While mean serum calcium was elevated compare to normal healthy control subjects.
Majed A Halwani
King Abdulaziz city for Science and Technology, Saudi Arabia
Title: Comparison for encapsulated gentamicin efficiency within different neutral and negative charged liposomal formulations for treating pathogenic lung bacteria
Time : 11:15-11:35
Biography:
Majed Halwani currently working as an Associate Research Scientist at Antimicrobial and Vaccine Development unit, King Saud bin Abdulaziz University for health sciences, Kingdom of Saudi Arabia - Riyadh
Abstract:
Background: Associated pneumonia with antimicrobial resistant pathogens is a worldwide concern. New antimicrobial agents are sparse and such infections will become a major challenge. Liposomal formulations are of proven superiority in delivering drugs to end organs and have the ability to protect drugs from metabolites and other host's harsh materials and at the same time reduce toxicity. The goal of this study is to evaluate different neutral and negative liposomal-gentamicin formulations for their encapsulation efficiency, stability, and antibacterial activities. Method: Neutral liposomal-gentamicin (NLG), negative charged liposomal-gentamicin-1 (NELG-1) & negative charged liposomal-gentamicin-2 (NELG-2) were prepared by dehydration-rehydration method. The particles sizes in the formulations were measured by light scattering technique. Loaded gentamicin within different liposomal nanoparticles was measured by microbiological assay. Minimum inhibitory concentration (MIC), minimum bactericidal concentrations (MBC), and killing time curve were studied on several bacterial gram negative / positive strains. Liposomal formulations’ stability were studied within different biological conditions include plasma, sputum, and BAL at 37 áµ’C. Results: The encapsulation efficiency of gentamicin within NLG, NELG-1, and NELG-2 were 1.8%, 37.2% and .43.6% respectively. Formulations stability of each of NLG, NELG-1, and NELG-2 in presence of some of the biological fluids such as bronchial alveolar lavage (BAL), human plasma, and sputum were studied at 37áµ’C for 48 hours. NLG, NELG-1, and NELG-2 were kept interestingly amount of gentamicin among those biological fluids, but when exposed to human plasma their content of gentamicin were mild dropped down. Bacterial eradication of several planktonic pathogenic ATCC strains by NLG was 2-fold lower than free gentamicin, whereas NELG-1 and NELG-2 eradicated them as same as free gentamicin. The killing time curve values at 1, 2 and 4 time MIC for our formulations against P. aeruginosa were better than free gentamicin. Interestingly, NELG-2 reduced biofilm formation by 2-fold on day 2 better than NLG and NELG-1 compared to free gentamicin. Conclusion: All formulations exhibited a bactericidal effect able to eradicate bacterial strains at low concentration when compared to free gentamicin. On the other hand, these formulations exhibited improved killing time and anti-biofilm forming. Our endeavors are ongoing to examine theses formulations toxicity profile.
Alessandro Pini
University of Siena, Italy
Title: A novel synthetic antimicrobial peptide for the cure of gram-negative infections: Mechanism of action, efficacy in vivo, toxicity, bio-distribution and resistance selection
Time : 11:35-11:55
Biography:
Alessandro Pini is a Professor of Biochemistry at the University of Siena, Italy. He is Founder and President of SetLance SRL, a start-up company in Siena with a special focus in the identification and early development of peptide based-drug. He is author of dozens of publications and inventor in 10 patents.
Abstract:
A synthetic antimicrobial peptide was identified some years ago as possible candidate for the development of a new antibacterial drug. The peptide showed a MIC 90 below 1.5 µM for Pseudomonas aeruginosa and Klebsiella pneumonia. In models in vivo of P. aeruginosa lethal infections the peptide and its pegylated form, allowed a survival percentage ranging between 65-80% in sepsis and lung infections when injected IV, and completely resolved skin infections when administered topically. Plasma clearance demonstrated different kinetics for both peptides, with a higher persistence for the pegilated one after two hours from injection. Bio-distribution in organs did not show significant uptake differences between the two peptides. Contrary to colistin, the molecule here described did not select resistant mutants in bacterial cultures. Moreover it resulted non-genotoxic and with an in vivo toxicity comparable to antimicrobial peptides already used in clinic. The characterizations here reported are part of a preclinical development plan that should bring the molecule to clinical trials in the next years.
Onaolapo J A
Ahmadu Bello University, Nigeria
Title: Antibiotic susceptibility profile of methicillin resistant Staphylococci aureus in poultry farm, in Zaria, Nigeria
Time : 11:55-12:15
Biography:
Josiah Ademola Onaolapo from Department Of Pharmaceutics and Pharmaceutical Microbiology, Ahmadu Bello University, Zaria, Nigeria
Abstract:
Methicillin antibiotic is not commonly used in veterinary practice in the hospitals due to its toxicity, but the wide spread of its gene (MecA) calls for concern in livestock.The epidemiological and antibiotic susceptibility of Staph. aureus in Zaria, Nigeria was carried out in this study due to the increasing resistance associated with Staph. aureus in poultry birds. In this study, 250 samples of chicken droplets were collected from five different poultry farms (50 samples from each farm) within Zaria metropolis. Eighty eight (88) isolates of Staph. aureus were confirmed using standard microbiological methods. The antibiotic susceptibility pattern showed that the isolates where 90.8% susceptible to Ciprofloxacin, 76.2% to Vancomycin, 72.2% to Pefloxacin, 65.6% to Gentamicin, 58.8% to Methicillin, 57.6% to Oxacillin, 49.6% to Ampicillin and 25.3% to Tetracycline. Their percentage resistance varied from 9.2, 23.9, 27.8, 34.4 and 42.4 for Ciprofloxacin, Vancomycin, Pefloxacin, Gentamycin and Oxacillin, respectively. The isolates showed high resistance 74.7% and 50.4% to Tetracycline and Ampicillin respectively while 41.2% of the isolates were resistant to Methicillin and produces β-lactamase enzyme. Seventy five percents (75%) of the isolates had MIC value of ≥64µg/ml while 25% had MIC ≤2 µg/ml. The MARI result showed that 40% of the isolates had MAR index of ≤0.3 while 60% had MARI of ≥0.4; indicating that the Staph. aureus tested were pre-exposed to the antibiotics used in this study. Further study on the 42.4% isolates that were resistant to Oxacillin showed that 60.5% and 64.8% were still resistant on mannitol salt agar impregnated with 4 µg/ml of Vancomycin and 67.6% and 70% of the same isolates grew on brain heart infusion agar impregnated with 6 µg/ml of Vancomycin after 24 and 48 hours incubation at 37o C respectively. This study showed high incidence of Staph. aureus and antibiotics resistance among poultry birds in Zaria, Nigeria and calls for antibiotic surveillance and education of the poultry farm workers to curb the wide spread of resistance gene which could be transferred in zoonotic diseases.
Sanjib Bhakta
University of London, Uk
Title: Common non-steroidal anti-inflammatory drugs (NSAIDs) in the fight against tuberculosis (TB)
Time : 12:15-12:35
Biography:
Following a BSc (Hons), an MSc and a PhD in Molecular Biology & Biochemistry from world class Universities & Research Institutions in India, Dr Sanjib Bhakta joined the Oxford University, Department of Pharmacology as an ISIS innovation Senior Research Scholar and shortly after he was awarded with a Wellcome Trust International Travelling Fellowship. He graduated from The Queen’s College, University of Oxford completing a second doctoral degree (DPhil) and received a “Sir William Paton Prize†in Pharmacology. He attained his first academic appointment at Birkbeck as a University Lecturer to lead his interdisciplinary research to tackle infectious diseases like TB.
Abstract:
Tuberculosis (TB) remains a serious healthcare issue, more than two decades on from the first time it was declared as a global health emergency. Control of the disease has become increasingly difficult because of the alarming rise of antibiotic resistance in Mycobacterium tuberculosis, the etiological agent of TB. Development of new and effective drugs with novel mechanisms of action is thus of paramount importance to tackle antibiotic resistance. Novel chemical entities require at least a decade to be commercially available and repurposing drugs offers a solution to circumvent the investment of time and other resources (1). Certain common non-steroidal anti-inflammatory drugs (NSAIDs) have proven to be selectively bactericidal against replicating, non-replicating and multi-drug-resistant clinical isolates of M. tuberculosis (2, 3). Our primary focus is to repurpose carprofen and investigate their novel mechanisms of action in M. tuberculosis to help design more potent inhibitors in the future. To this effect we have followed both target-based and whole-cell approaches. Whole-cell transcriptomic analyses have revealed the effects of the drugs on a selected set of genes involved in key metabolic pathways that also play essential roles in antimicrobial resistance. Furthermore, the NSAIDs showed influence on the expression levels of proteins involved in cell-wall homeostasis and dormancy mechanisms. The most active NSAID, Carprofen was found to be a bactericidal drug that also inhibited the formation of mycobacterial biofilms and exhibited strong efflux pump inhibitory properties thus demonstrating their great potential in reversing antibiotic resistance.
Arun G Ingale
North Maharashtra University, India
Title: DENV3 envelope protein of dengue virus: A potential target for the vaccine designing
Time : 12:35-12:55
Biography:
Arun G Ingale has obtained his PhD in Biotechnology from Sant Gadge Baba Amravati University, India. He was the Founder, Head, Department of Biotechnology, Dr Babasaheb Ambedkar Marathwada University, India. He is President of Society for Biotechnology and Bioinformatics, India. He is also the Editor in-Chief of the Journal of Biotechnology and Bioinformatics (JBB) and International Journal of Modern Biotechnology. His primary field is immunology with research emphasis on CD antigens and the structure-function prediction using Bioinformatics approach. He has recently entered the developing field of Lectin Biosensor and Glyco-Nanobiotechnology research. In Genomics research area he has been working on constructions of transgenic Okra against pest (Lipidopteron) and pigeon pea against bollworm. In proteomics research area he is working on proteomics of lectin and other plant and microbial proteins. In bioinformatics, he has developed a database of CD markers and Toxin database is on completion. He has published several research papers in national and International journal of repute. He has submitted protein and nucleotide sequences on NCBI and viral protein models are being submitted in PDB database. Currently, he is holding Major research projects as a Principal Investigator and Head Department of Biotechnology, North Maharashtra University.
Abstract:
Dengue is arthropod-borne viral disease mainly found in Southeast Asia, the Pacific and the Americas. There are four antigenically discrete serotypes of dengue viruses (DENV1-4) each of which is competent of causing dengue fever, hemorrhagic fever and dengue shock syndrome and currently circulating in these areas. An estimated 50 million dengue infection cases occur globally with around 500,000 cases of hemorrhagic dengue and 20,000 deaths per year. In India, numbers of dengue fever cases are increasing every year. Currently, vaccines and antiviral drugs are under investigation could also make vital contribution to dengue control in the future. Hence, there is dire aspiration to develop new vaccine or drugs that are more targeted fewer lethal and more successful against this virus. Here we analyzed structural components of DENV3 envelope protein for development of homology model and prediction of their antigenic determinants. This work may contribute to effectively target and cultivate operational epitope vaccine to defend the host from the virus.
Bincy Joseph
Kerala Veterinary and Animal Sciences University, India
Title: Effective protection by high efficiency bicistronic DNA vaccine against anthrax expressing protective antigen and catalytically inactivated lethal factor
Time : 13:40-14:00
Biography:
Bincy Joseph has completed her Graduation in Veterinary Sciences (BVSc & AH) from Kerala Agricultural University with KAU merit scholarship. She has completed Post graduation in Veterinary Bacteriology from Indian Veterinary Research Institute with ICAR Junior Research Fellowship and completed Doctorate in Veterinary Bacteriology from Indian veterinary research institute with Senior Research Fellowship. She has published 8 research articles in various reputed journals and participated in more than 10 national and international conferences and presented research papers.
Abstract:
Limitations of currently available anthrax spore vaccine necessitate the development of an improved vaccine for animals. In the present study lethal factor gene of Bacillus anthracis was made catalytically inactive by primer based site directed mutagenesis. To explore whether immunization with plasmid encoding this mutated lethal factor (mLF) and protective antigen (PA) can provide protection against anthrax, a bicistronic DNA vaccine encoding PA and mLF was then made along with mono-cistronic constructs encoding PA/ mLF. The ability of the constructs to express the encoded genes was verified by transfection in MDBK cells followed by indirect immunofluorescence analysis. To investigate the immunogenic potential of the made constructs immunization trials were conducted in mice. After primary immunization with these DNA vaccines the mice were boosted with DNA vaccines, recombinant proteins or formalin inactivated spores (FIS) on 14thand 28th days post vaccination. Subsequently, indirect ELISA, toxin neutralization assays (TNA) and monitoring of cytokines (IL-4, IL-2 and IFN-γ) were done to monitor the immune response. The direct challenge test of immunized mice was done using 1000 LD50 of virulent B. anthracis IVRI strain. The results showed that the heterologous prime boost regimen involving priming with bicistronic DNA construct encoding PA and mLF or mono-cistronic DNA construct encoding PA and boosting with recombinant proteins can provide better protection (66.66%) compared to other groups. At the same time immunization with bicistronic DNA construct encoding PA and mLF and boosting with recombinant proteins could provide higher antibody titer, toxin neutralization titer and Th1 and Th2 response (p<0.0001) compared to all other groups illustrating that DNA vaccine encoding PA and mLF conferred a broader spectrum of immune reaction than PA alone. The increase in serum concentration of IL-2, 1L-4 and IFN-γ indicated that both humoral and cell mediated immune response were elicited by DNA vaccination. Thus, the results of the present study indicatedthe feasibility of DNA prime protein boost based immunization strategy based on PA and mLF being developed into nontoxic, effective and stable anti-anthrax vaccine.
Whika Febria Dewatisari
Universitas Terbuka, Indonesia
Title: Antimicrobial activity of the saponin extract of Sansevieria trifasciata var. Golden Hahnii
Time : 14:00-14:20
Biography:
Whika Febria Dewatisari is an Academic Staff at Department of Mathematic and Natural Science in Open University (Universitas Terbuka) Bandar Lampung-a public university in Indonesia. She is a Biology Lecturer and started working at 23 years old. She teaches courses in Plant Embriology, Microbiology and Ecology
Abstract:
Sansevieria trifasciata used as an ornamental plant. It also used as a traditional medicine for influenza, cough and inflammation of the respiratory tract. The roots and leaves of S. trifasciata contains many secondary metabolites such as saponins that efficacious as a cough remedy to treat sprains, injuries hit, venomous snake bites, ulcers, cough, inflammation of the respiratory tract and hair growth. Microbes are used to seeing the antibacterial saponins activities of S. trifasciata are Escherichia coli and Staphylococcus aureus. The main reason for used these microbes because E. coli is a bacterium that causes diarrhea and S. aureus is one of the bacteria that cause cough in humans. Plants were used S. trifasciata var. Golden Hahnii. Based on research by Dewatisari (2008), states that the variety had the highest saponin content of S. trifasciata is Golden Hahnii among other varieties and the parts that had the highest saponin were in its roots. This article aims to explain quantitatively the effectiveness of saponin compounds from the roots of S. trifasciata var. Golden Hahnii as anti-microbials in inhibiting the growth of bacteria S. aureus and E. coli. Methods of data collection were sample preparation, a preliminary test, the extraction of saponins, antibacterial activity test and isolate compound separation by TLC (Thin layer Chromatography). This study includes the extraction of the active compounds in the roots of S. trifasciata by maceration with methanol 90%. Separation of the active compound was conducted by TLC. Eluent used was chloroform; methanol; water with various concentration (13: 4: 1), (65; 50: 10), (20: 60: 4), 20: 60: 10). Antibacterial test conducted by the disc diffusion method against S. aureus and E. coli. Identification of test compounds triterpenoid saponins using foam and Liebermann-Burchard color test (LB). The results showed that the extract of the roots has potential as anti-bacterial. The extract was able to inhibit the growth of E. coli and S. aureus. At the optimum concentration of 200 ppm produced inhibition zone was 26.5 mm to 20.2 mm for S. aureus and E. coli. Best eluent to separate the triterpenoid saponins in root extracts of S. tifasciata was chloroform; methanol; water at a concentration (20: 60: 4) with 3 separate visible stains are: 0.135; 0.85; 0.815. Mechanism root extract as an anti-bacterial S. trifasciata was synergistic. It was seen from the inhibition zone, for E. coli isolates I=5.52 mm and isolates II=2.50 mm, for S. aureus isolates I=1.52 mm and isolates II=0.58 mm while the isolates III is not effective as an anti-bacterial.
Yanmin Hu
University of London, UK
Title: Antimicrobial peptide novicidin synergises with rifampicin, ceftriaxone and ceftazidime against antibiotic-resistant gram-negative Enterobacteriaceae in vitro
Time : 14:20-14:40
Biography:
Yanmin Hu is a Senior Research Fellow at St George’s, University of London. Her main research interests are in tuberculosis and antibiotic discovery. The scientific and intellectual imperatives for her research include new drugs and better drug regimen for tuberculosis and other important infectious diseases; improved chemotherapy to eradicate persistent bacteria; molecular approaches to understand the processes of infection and pathogenesis of M. tuberculosis and other pathogens.
Abstract:
Infections caused by gram-negative bacteria species such as those in the Enterobactericeae family are responsible for high rates of morbidity and mortality. The spread of antibiotic resistance amongst gram-negative pathogens is a serious clinical threat requiring urgent attention. Traditional novel drug development inevitably leads to emergence of new resistant bacterial strains, rendering the new drugs ineffective. Therefore reviving the therapeutic potentials of existing antibiotics represents an attractive novel strategy. Novicidin, a novel cationic antimicrobial peptide is effective against gram-negative bacteria. The actions of novicidin in combination with rifampicin, ceftriaxone and ceftazidime were investigated. We performed in vitro investigations to test against 94 antibiotic resistant clinical Gram-negative isolates and 7 strains containing New Delhi metallo-β-lactamase-1 (NDM-1). The effects of combining novicidin with rifampicin, ceftriaxone and ceftazidime were examined using the chequerboard method and time kill curves. A fluorescence assay was used to investigate the depolarisation of the bacterial cell membrane by novicidin. The post antibiotic effect was measured. The cytotoxicity and haemolysis of novicidin were examined using neutral red uptake in the L929 fibroblast cell line and lysis of human blood. Novicidin combined with rifampicin showed synergy with over 70% of the tested gram-negative clinical isolates (n=94) and NDM-1 strains (n=7) reducing the MIC significantly. The combination of novicidin with ceftriaxone and ceftazidime showed synergistic effects with more than 89.7% of ceftriaxone-resistant strains and 94.1% of ceftazidime-resistant strains. These synergistic combinations were also demonstrated using time kill studies with multiple strains. We also demonstrated that novicidin altered the cytoplasmic membrane potential by membrane depolarisation against both Escherichia coli and an isolate from the Klebsiella-Enterobacter-Serratia (KES) group. Furthermore, novicidin was shown to increase the post-antibiotic effect (PAE) when combined with rifampicin or ceftriaxone. Novicidin showed low haemolytic activity and conservation of cell viability in the cell culture post treatment. We demonstrated that novicidin strongly rejuvenates the therapeutic potencies of ceftriaxone or ceftazidime against ceftriaxone or ceftazidime resistant gram-negative bacteria in vitro. In addition, novicidin boosted the activity of rifampicin. This strategy can have major clinical implications in our fight against antibiotic resistance bacterial infections.
Hosseini Seyed Davood
Razi Vaccine and Serum Research Institute, Iran
Title: Amplification, cloning and expression of Brucella melitensis bp26 gene (OMP28) isolated from Markazi province (Iran) and purification of Bp26 protein
Time : 14:40-15:00
Biography:
Hosseini Seyed Davood is currently as Dean for Razi Vaccine & Serum Research Institute Central Area branch(Arak), Iran
Abstract:
Brucellosis is a debilitative disease that imposes costs on both economy and society. It is shown that although the vaccine can prevent abortion, it does not provide complete protection against infection. In Iran, Brucella melitensis is a common causative agent for brucellosis and BP26 protein of this bacterium having a good antigenesity and an important vaccine candidate. In this study B. melitensis bp26 gene was cloned first in to PTZ57R/T vector and accessed on the PET28a vector and sequenced. Recombinant vector transformed and expressed in to E. coli BL21 (DE3) and then recombinant protein was purified with Ni-NTA column of chromatography against His tag. Obtained rOmp28 could be used as a research experimental tool to find its potential as a detection kit and vaccine candidate.
Collins Njie Ateba
North West University, South Africa
Title: Genetic characterization of antibiotic resistant Enterococcus faecalis isolated from groundwater in North West Province, South Africa
Time : 15:00-15:20
Biography:
Collins Njie Ateba has completed his PhD from the North West University - South Africa. He also received professional training in the Centre for Medical Genetics, Yerevan State University, Yerevan – Armenia in 2006 in the Department of Microbiology- Tartu University Tartu – Estonia in 2007 and the Lethbridge Research Station – Lethbridge Alberta, Canada in 2014. He is currently an Associate Professor in the Department of Biological Sciences, Microbiology Division, North West University –Mafikeng Campus and is head of the Water, Food Safety and Phage Therapy/Biocontrol Research Laboratory. He is actively involved in research training and lecturing at both undergraduate and postgraduate levels. He has been serving as a host mentor for the DST/NRF internship program from 2011 till date. He has published more than 30 papers in reputed journals and serving as an Editorial Board Member of repute. He has presented research papers in a number of conferences locally and internationally.
Abstract:
Enterococcus species are commercial organism usually inhabit the gastrointestinal tract of humans and animals. They are the indicators of faecal contamination in water and food and mostly enter into host through faecal-oral route. The presence of some pathogenic strains of Enterococci specifically vancomycin resistant Enterococcus faecalis cause nosocomial infection which become more prevalent in recent years and make situation more worse. In South Africa, mostly people in rural areas have no access to portable water and they depend on untreated water source. Therefore, they are at high risk of exposure to pathogenic microbes. Keeping this in view, present study was conducted to determine the presence of vancomycin resistant Enterococcus faecalis from the underground water from North West Province, South Africa. Enterococci were isolated from 60 borehole tap water samples on Bile Esculin agar. The presumptive isolates were analysed for the characteristics of Enterococcus faecalis using preliminary (Gram staining, catalase test, growth in 6.5% NaCl broth and haemolysis) and confirmatory (species specific 16S rRNA and ddlE. faecalis gene specific PCR) tests. The screened isolates were further subjected to antimicrobial susceptibility for 13 different antibiotics by standard disk diffusion method. Also, these isolates were screened for the presence of vancomycin resistant genes (vanA and vanB) and transposable elements (Tn1546 and Tn1547). A total of 253 presumptive isolates were obtained on Bile Esculin Agar and analysed for characteristics of Enterococcus faecalis using preliminary and confirmatory tests. A molecular typing confirmed 122 isolates as Enterococcus faecalis which were further screened for antimicrobial susceptibility. A large proportion of the isolates were multiple antibiotic resistant and showed resistance to vancomycin, penicillin, amoxicillin, ampicillin, tetracycline and erythromycin. The presence of vanB gene was observed in 83 isolates followed by 63 isolates harbouring vanA gene. Only 27 isolates which harbour vanA showed the presence of Tn1546 whereas none of the vanB positive isolates showed the presence of Tn1547. Conclusions: This study showed the presence of vancomycin resistant E. faecalis (multiple antibiotic resistant) from the underground tap water which is a cause of concern. Therefore, there should be a regular surveillance to monitor antibiotic resistant bacteria to prevent its spreading in nature. Further, detailed molecular study is required to know the deep insight into the genetic jugglery in these bacteria as in the present study a high level incompatibility between phenotypes and genotypes were observed.