Day 3 :
- Modern antibiotics: Emerging trends, Barriers and Opportunities
Antibiotics: Market Analysis & Business Opportunities
Antibiotic Regulatory Affairs
Antibiotics and Mechanism
Drug Discovery and Novel Delivery Technologies
Session Introduction
Glenn S Tillotson
TranScrip Partners USA
Title: Fluoroquinolones-A maligned class being re-discovered?
Biography:
Glenn Tillotson has 30+ years pharmaceutical experience in early pre-clinical and clinical research, commercialization, medical affairs, scientific communications including publication planning strategic drug development, life cycle management and global launch programs. Dr Tillotson has been instrumental in the development and launch of ciprofloxacin, moxifloxacin, gemifloxacin and other antibacterials. Glenn has held several key committee positions at the American College of Chest Physicians, he is on the Scientific Steering Committee for the GTCBio. Annual Summit on Anti-infective Partnering. Currently Dr Tillotson has published >140 peer-reviewed manuscripts, presented >270 scientific posters and is on several journal Editorial Advisory Boards including the Lancet Infectious Disease, eBioMedicine and F1000.
Abstract:
Background: Fluoroquinolones were discovered in the early 1980’s with norfloxacin and ciprofloxacin being early class members. In the intervening 30 years the group has expanded and contracted mainly due to a series of adverse events. The class was “cutting edge” due to the breadth of activity, the oral and IV formulations and significant tissue distribution. Indeed these characteristics enabled courses of therapy to be shortened with all those attendant benefits. In the past decade no further quinolones have been approved, why? A combination of safety worries association with Clostridium difficile infection and emergence of resistance among the pathogens for which the class was developed. Current status: The current global situation of antibiotic resistance among many pathogens is alarming and alternative agents are being sought, these include new members of the quinolone class. These agents are being developed based on either a novel mode of action or an expanded spectrum of activity. The local environment in an infected lesion or space is approximately pH 5 which can have adverse effect on some conventional antibiotics including current quinolones. The fluoroquinolones, delafloxacin and finafloxacin have better activity at the lower pH compared with MICs at pH 7.0. These two agents are being developed based on their enhanced activity against gram-positive and gram-negative pathogens, e.g. delafloxacin [MIC MRSA 0.5 mg/l] and finafloxacin [E. coli MIC 0.12 mg/l]. Thus these are being developed for acute bacterial skin and skin structure and complicated urinary tract infections respectively. The respiratory fluoroquinolones were vanguards of the shorter course therapy in respiratory infections based on many characteristics , most of which are harnessed by zabofloxacin which is highly active against an array of Streptococcus pneumoniae strains and penetrates lung compartments very well. Thus this drug is being examined for mild-moderate community acquired bacterial pneumonia with a 3 day course. This presentation will review the three new fluoroquinolones from microbiological, pharmacological and clinical perspectives with regard to the 3 different indications being studied
Mario A Bianchet
Johns Hopkins University School of Medicine, USA
Title: Mycobacterium tubercolosis cell-wall biosynthesis as target of Carbapenems
Biography:
Mario A Bianchet has completed his PhD from The University of La Plata, Argentine, and performed Postdoctoral studies at Johns Hopkins University School of Medicine in where he is now Assistant Professor of Neurology since 2011. He has published 65 papers in reputed journals. As structural enzymologist and expert in ligand recognition, he has participated in several seminal structural and mechanistic studies of macromolecules and ligand/macromolecule interactions of biomedical interest. He has important contributions to different fields, including bioenergetics: F1-ATPase, xenobiotic-response: NADPH:Quinone oxidoreductases, DNA-repair: Uracyl-Glycosylase/inhibitors, carbohydrate-recognition: animal lectins, and late stage cell-wall biosynthesis: LD-transpeptidases and their complexes with substrates and carbapenems
Abstract:
Transpeptidases play essential roles in the bacterial cell-wall biosynthesis. Inter-stems cross-links made for these enzymes assemble the peptidoglycan mesh that confer mechanic stability to the bacteria. β-lactam antibiotics, penincillin, inactivates (4-3) DD-transpeptidases. These transpeptidases also called penincillin-binding proteins,cross-linked-centers of the fourth residue main-chain with that of the third residue side-chain of adjacent peptidoglycan stems. Most bacteria utilize(4-3) crosslinks to build their peptidoglycan layer. However, the Mycobacterium genus and some penicillin-resistant bacteria—involved in nosocomial infections—majoritarily utilize the (3,3)-crosslinks carried out by (3,3) LD-transpeptidases. This (3,3)-crosslink joins the L-center of the third residue main-chain and the D-center of the another third residue main-chain of an adjacent stem. The use of this crosslink and the presence of a potent β-lactamase (BlaC) confers to mycobacteria resistance to penicillin and other antibiotics that mimic the D-Ala4-D-Alanyl5 terminal region of the pentapeptide donor stem recognized by DD-transpeptidases. LD-transpeptidases are resilient to this type of inhibition because they exclusively recognize a tetrapeptidedonor stem lacking the D-alanyl terminal. Carbapenems are β-lactam antibiotics that have a carbon atom replacing the sulphur atom at position1 of the penicillin core. This class of antibiotics inactivate LD-transpeptidases by a quasi-irreversible acylation of the enzyme catalytic cysteine, resulting in a effective agent to treat these penicillin-resistant bacteria. We are going to discuss our recent structural, biophysical, and biochemical characterization of members of this family of enzymes and their complexes with a series of carbapenemsin medical use.
Michael kelso
University of Wollongong, Australia
Title: Biofilm Dispersing NO-Donor Cephalosporins Activated by b-Lactamase
Biography:
Kelso graduated from the University of Wollongong with a B. Medicinal Chemistry (1996) and received his PhD (Peptidomimetics, 2002) from the University of Queensland (Australia). After a 1-year postdoc with Prof Claudio Palomo (Universidad del Pais Vasco, Spain) studying catalytic asymmetric synthesis he moved to The Scripps Research Institute (CA, USA), where he studied medicinal chemistry as an NHMRC CJ Martin Fellow under Professor Dale Boger. Upon returning to Australia in 2006 he completed his Fellowship under Prof John Bremner at the University of Wollongong, where he was subsequently appointed as a lecturer (2008) and promoted to A/Prof (2014). His research group focuses on the design, synthesis and biological evaluation of antibacterials acting via novel mechanisms
Abstract:
Low concentrations of nitric oxide (NO) have been shown to act as a signal that induces biofilm bacteria to disperse and revert to the free-swimming (planktonic) form. This finding unveiled an exciting new anti-biofilm paradigm; i.e. use of NO-donor compounds in combination with antibiotics to clear chronic biofilm infections, sinceit is well-known that planktonic bacteria are up to 1000x more susceptible to antibiotics and host immune defences than their better-protected biofilm counterparts. Based on this discovery, we have designed, synthesized and provided in vitro proof-of-concept validation for a novel class of cephalosporin-based NO-donor prodrugs (DEA-CPs) that can provide biofilm-targeted NO delivery. The targeted NO signal from DEA-CPs (activated by ß -lactamases) induces biofilms to disperse and when used in combination with clinical antibiotics the compoundsare able to clear biofilms. The seminar will highlight key results in this area, including our latest efforts to translate DEA-CPs for use against chronic respiratory P. aeruginosa biofilms in cystic fibrosis patients.
Ganjun Yuan
Jiangxi Agricultural University, China
Title: Anti-methicillin-resistant Staphylococcus aureus assay of azalomycin F and its derivatives
Biography:
Ganjun Yuan has completed his PhD from Hainan University and has been researching on pathogenic microbe in Luisana State University Health Sciences Center for six months. He is the Director of Analysis & Test Center, Jiangxi Agricultural University. He has published more than 40 papers in reputed journals and has been serving as a Council Member of Jiangxi Pharmacological Society in China and a Senior Member of Chinese Pharmaceutical Association
Abstract:
To discover anti-methicillin resistant Staphylococcus aureus (anti-MRSA) compounds, the anti-MRSA activities of many natural products from plants and microorganisms were evaluated in my lab, and even those of some known medicines were deduced from their structures and proved by reasonable experiments. Azalomycins F5a, F4a and F3a, three main components of azalomycin F with broad-spectrum antimicrobial activity, were 36-membered polyhydroxyl macrolides produced by Streptomyces hygroscopicus var. azalomyceticus or Streptomyces sp. 211726. After their relative configurations were reported by us, their anti-MRSA activities were first assayed with agar diffusion and broth microdilution methods. The results showed that their minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations against MRSA ATCC33592 and eight clinical isolates MRSA 01-08 were 3.0-8.0 and 8.0-16.0 μg/mL, respectively. To further improve their anti-MRSA activity, stability and water solubility, eleven azalomycin F derivatives were synthesized through direct hydrolysis with NaOH in MeOH or through hydrocarbylation in hydrocarbyl alcoholic-AcOH and subsequent demalonylation with KOH in MeOH-H2O. The antimicrobial assays of these derivatives showed that the anti-MRSA activities of demalonylazalomycin F and 17-alkyl demalonylazalomycin F5a derivatives were respectively 8-16 and 4-6 times those of azalomycin F and azalomycin F5a, while those of the 17-alkyl azalomycin F5a derivatives showed no enhancement. Moreover, the checkerboard assays indicated that azalomycin F5a, F4a or F3a combined with vitamin K3 showed synergistic activities against MRSA and their fractional inhibitory concentration indices were 0.25-0.50. With remarkable anti-MRSA activity, stronger stability, moderate water solubility and antifungal activity indicated that demalonylazalomycin F had a high potency as anti-MRSA agents.
Biography:
Andrei L Gartel, PhD is an Associate Professor in Department of Medicine at the University of Illinois at Chicago, and the academic editor of PLOS ONE. He is the author of 86 peer-review publications with more than 8500 citations and with H-index 35. His scientific interests are cancer, cell cycle, transcriptional gene regulation, cyclin-dependent kinase inhibitors including p21, regulation of oncogenic transcription factors FOXM1 and c-Myc. He showed that thiazole antibiotic thio-strepton targets FOXM1 and could be delivered in nanoparticles to cancer cells to suppress FOXM1.
Abstract:
The oncogenic transcription factor forkhead box M1 (FOXM1) is overexpressed in human cancer, while its expression is turned off in terminally differentiated cells. For this reason, FOXM1 is an attractive target for anticancer drugs. Using a high-throughput, cell-based assay system, we screened for and isolated the antibiotic thiazole compound Siomycin Aas FOXM1 inhibitor. Next, we found that structurally similar thiazole antibiotic, thiostrepton also inhibits the transcriptional activity and expression of FOXM1. The thiazole antibiotics efficiently inhibited the growth and induced strong apoptosis in human cancer cell lines of different origin. It turned out that Siomycin A and thiostrepton act as proteasome inhibitors in mammalian cells. In addition, we showed that thiostrepton, when formulated into nanoparticles, is highly suited for delivery to tumors. We decided to examine whether other known thiazole antibiotics such as berninamycin, micrococcin P1 and P2, thiocillin and YM-266183 (lacking the quinaldic acid ring B) also have this activity. Several thiazole antibiotics have a macrocyclic loop connecting thiazole rings at position 2 and 3 described as ring A, while thiostrepton and Siomycin A have in addition a quinaldic acid macrocycle also connected to thiazole on position 2 described as ring B. We found that berninamycin, micrococcin P1 and P2, thiocillin and YM-266183 do not act as proteasome inhibitors. Moreover, structural modification of thiostrepton to thiostrepton methyl ester (with open B ring) also did not show this activity. These data suggest that A and B rings are required for the proteasome inhibitory activity of these drugs.
Jorge Ernesto Guevara Vasquez
National University Mayor de San Marcos – Lima-Perú
Title: Use of Probiotics in Guinea Pigs (Cavia porcelllus)
Biography:
Jorge Guevara Vásquez completed his PhD at the National University Agraria La Molina, Lima – Perú. Currently he is working as a teacher and a member of the Research Group on Animal Nutrition (GINA) of the National University Mayor de San Marcos. He has published articles in various journals on research in the area of nutrition and animal production. Sponsor of his thesis are students of undergraduate and graduate degrees to obtain corresponding academic degree.
Abstract:
The objective is to isolate and identify the bacterial isolates by molecular techniques belonging to genera with potential for probiotics in the intestine of guinea pig (Cavia porcellus) and evaluate this productive parameters supplemented with this probiotics, the intestine was extracted from each sample were taken by scraping the intestinal mucosa, they were planted in different culture media in order to achieve isolated colonies with phenotypic characteristics of bacterial species of known potential probiotic (Lactobacillus, Enterococcus, Streptococcus, Bacillus, Bifidobacterium). We identified 27 representative isolates by amplification, sequencing and bioinformatic analysis of 16S rRNA gene. DNA sequences were compared with three different databases. It turned out that 85.18% obtain Lactobacillus, Enterococcus, Streptococcus and Bacillus, the 14.81% remaining bacterial species gram positive identified that are not objective of this study, but that however, contribute to the identification of guinea pig intestinal microbiota, was found Staphylococcus. Then it was to evaluate the productive parameters of guinea pigs supplemented with this probiotics. Five treatments with eight replicates per treatment were used: T1, T2 and T3 received 100, 150 and 200 ml of probiotic, respectively, and T4 and T5 were positive and negative controls, respectively. The dry matter intake, weight gain, feed conversion and carcass yield were evaluated. T2 had the lowest dry matter intake (2564 g) and the lowest feed conversion (3.90) and T5 increased consumption (3293 g) and increased feed conversion (5.04). Weight gain and carcass yield were not affected by the probiotic. The dietary inclusion of probiotic strains from guinea pig intestinal microbiota affected (p<0.05) feed conversion in growing and fattening guinea pigs.
- Video Presentation
Session Introduction
Baló-Banga J M
Medical Center of the Hungarian Defense Forces, Hungary
Title: Evaluation of antibiotic hypersensitivity in hospital setting. In vivo and in vitro testing by using standardized epicutaneous, intradermal, oral provocation tests and a rapid IL-6 release assay on the peripheral mononuclear cells
Biography:
Baló-Banga J M is working in Dermato-Allergy Unit at the Department of Dermatology Medical in Hungary
Abstract:
Background: Antibiotics are amongst the most frequent causes of drug hypersensitivity. Aim: To study the appearance of mostly skin related hypersensitivity events due to this very heterogeneous group of drugs in our hospitalized and out-patient material between 2007-2013 in order to analyze their culprit role. Methods: The total number of patients was 136 that of matching control 29. Most patients were seen at the Emergency Unit of our hospital and sent after consultation as in- or outpatient for further clarification. According their history and symptoms 45% were definitely, 19% probably, 19% possibly hypersensitive to one or more drugs. Within the control group in 67% drugs as causative agents could be ruled out and in 33% their role has emerged as possibility. All tests have been carried out between 2-8 months after the event. In vivo methods included patch testing by pure drugs (10% w/w in petrolatum), intradermal tests by 1 mM drug solutions and oral provocations introducing incremental doses over 3 hrs. In vitro tests were developed to exploit the rapid (20’) release of preformed IL-6 from ex vivo T-cells due to sensitizing drugs. Many in vivo-in vitro tests were run inparallel. Results: Fourty two patients and 5 controls were tested with various antibiotics according their histories. The number of positive in vitro tests was 31 and that of negative tests 29. Within the control group 9 negative tests were noted. Most tests (32/60=53%) were performed with ß-lactams (penicillins and cephalosporins), followed by clindamycin (8/60=13%), fluoroquinolones (5/60=8%) sulfametoxazole (4/69=7%), doxycycline (3/60=5%), metronidazole (3/60=5%) and clarythromycine (2/60=3%). The highest positivity rate was found to amoxicillin (8/14=57%) but both false negative and false positive results (1-1) relative to in vivo tests were noted. The lowest positivity rate (0/4=0%) could be found with sulfametoxazole. The intradermal tests with 10-3M vancomycin gave false positive results in 3 controls tolerating this drug. Therefore, its test concentration has been lowered to 10-4 M. The phenotypic expression of antibiotic hypersensitivity fell into the following categories: circumscribed (17%) and generalized (30%) maculopapular rash, severe perioperative angioneurotic edema with dyspnoea, cardiac arrest (6,4%), generalized hives , diffuse erythema + fever (4,3%) circumscribed angioneurotic edema or urticaria (27,6%), severe intertriginous and flexural exanthema(SDRIFE), induced asthma, fixed drug eruption, loss of consciousness; one case each (14,7%). Non-immediate reactions were more common. Conclusion: In vivo and in vitro tests carried out successively are needed to demonstrate drug induced hypersensitivity to antibiotics taking into account the clinical picture and differential diagnostic approach. IL-6 release assay has gained a solid place in the procedure.