Day 2 :
Keynote Forum
Hsiu-Jung Lo
National Health Research Institutes, Taiwan
Keynote: Fluconazole-resistant Candida tropicalis in Taiwan: An emerging environmental threat to human health
Biography:
Hsiu-Jung Lo has completed her PhD from Indiana University at Bloomington, USA and postdoctoral researches from Whitehead Institute for Biomedical Research, USA. She is the Deputy Director of National Institute of Infectious Diseases and Vaccinology, and the Executive Secretary of National Mosquito-Borne Diseases Control Research Center, National Health Research Institutes, Taiwan. She published morethan 70 papers in reputed journals.
Abstract:
Fluconazole resistance of Candida tropicalis, the leading non-albicans Candida spp. causing candidemia in humans residing in tropical Asia and Latin America, is troublesome for healthcare. This study was designed to determine the potential role of agricultural azole-fungicides on the emergence of fluconazole-resistant C. tropicalis in environments and in humans with systemic infections. Yeasts sampled from fruits, soils, water, and farmers in 82 farms were identified by ribosomal DNA sequencing. Multilocus sequence typing was further used to determine the genetic relationships of C. tropicalis isolates from the agricultural sites to those isolated from patients. Of 698 individual yeasts from 478 samples, 449 (64.3%) were from the environment and 249 (35.7%) from farmers. The most common Candida spp. causing diseases in humans recovered from the farmers was Candida albicans (14.9%), followed by Candida parapsilosis (11.6%). In contrast, C. tropicalis (13.1%) and Candida krusei (6.0%) were prevalent in the environment. Nine of 10 (90%) and 22 of 25 (88%) fluconazole-resistant C. tropicalis from environments and patients, respectively, were genetically related. Overexpression of ERG11, the azole target, contributed to fluconazole resistance. Most patients (18/25) were azole-naïve. Furthermore, there was no evidence of human-to-human transmission. The identification of fluconazole-resistant C. tropicalis from agricultural sites where azole-fungicides are commonly applied allowed documenting close genetic relationship to isolates from patients with invasive infections supports the concept that the microorganisms were transmitted from the farms to humans. Further studies are needed to determine the possible route of fluconazole-resistant C. tropicalis transmission in clinical settings.
- Human Virology and Infectious Diseases | Viral Oncology | Antibiotics, Antimicrobials and Chemotherapy | Infection and Immunity | Biofuels and Petroleum Microbiology | Biofilms Formation | Antimicrobial Drugs
Location: Renaissance polat Istanbul Hotel
Chair
Ahmet Kati
University of Health Sciences, Turkey
Session Introduction
Lina M Elsalem,
Jordan University of Science & Technology, Jordan
Title: Synergistic effects of antimicrobial peptide WLBU2 combined with antibiotics against multidrug-resistant bacteria associated with wound infections
Biography:
Lina M Elsalem has completed her PhD in Pharmacology from Faculty of Life Sciences at University of Bradford, UK. She is currently working as an Assistant Professor in the Department of Pharmacology at Faculty of Medicine, Jordan University of Science and Technology.
Abstract:
Microbial resistance against conventional antibiotics is considered as a substantial health and economic burden to any health care system. Accordingly, research in the antimicrobial field has been directed toward the development of new agents such as the engineered cationic amphipathic peptide WLBU2. The aims of this study are: To evaluate the antimicrobial effects of WLBU2 against multi-drug resistant strains of bacteria including Gram-negative Enterobacter cloacae (ESBL+ve) and Gram-positive Methicillin-resistant Staphylococcus aureus (MRSA) and to assess whether synergistic effects can be achieved upon combination treatment of WLBU2 with conventional antibiotics. Clinical isolates of Enterobacter cloacae (ESBL+ve) and MRSA (n=30 for each) were obtained from wound infections in microbiology laboratories of the Jordanian Royal Medical Services. The Minimum Inhibitory Concentration (MIC) for WLBU2 and conventional antibiotics were determined using the microbroth dilution assay, according to CLSI-2017 guidelines. The antibiotics Ceftazidime, Ciprofloxacin and Ceftriaxone were used for Enterobacter cloacae (ESBL+ve), while MRSA was treated with Oxacillin and Erythromycin. The Fractional Inhibitory Concentration (FIC) index was utilized to determine the relationship between antimicrobial agents upon combination of sub-inhibitory concentration of WLBU2 with conventional antibiotics. The MIC for WLBU2 against Enterobacter cloacae (ESBL+ve) and MRSA ranged from (1.5 to 12.5) μg/ml and (0.78125 to 6.25) μg/ml, respectively. Synergistic and additive effects were achieved in Enterobacter cloacae (ESBL+ve) upon combination treatment with Ceftazidime (n=7/30, 17/30), Ciprofloxacin (n=9/30, 17/30) and Ceftriaxone (n=10/30, 17/30) respectively. Regarding MRSA, synergistic and additive effects were obtained with Erythromycin- WLBU2 treatment (n=2/30 and 10/30, respectively), while only additive effects were observed with Oxacillin- WLBU2 combination (n=14/30). Our data reveal that WLBU2 is a potent peptide with antimicrobial activity against Enterobacter cloacae (ESBL+ve) and MRSA. Our findings also support the development of WLBU2 in combination with conventional antibiotics with potential application for treatment of multidrug resistant bacteria associated with wound infections.
Biography:
Samia Hamma-Faradji is a teacher & researcher in the University of Bejaia, Algeria.
Abstract:
Algeria is a country traditionally a consumer of fermented milk products, which until recently was manufactured in rural areas, mainly for self-consumption, by spontaneous fermentation of locally produced raw milk. On the one hand, non-compliance with good hygiene practices during milking, makes these products in several cases causing food poisoning; on the other hand the increased use of antibiotics for the treatment of dairy cows has contributed to the growing emergence of antibiotic-resistant bacterial strains. The development of natural control means with respect to thèse multi résistant Stains is Born as the use of lactic bacteria endowed with antibacterial activity. In this context, isolation of strains of S. aureus is made from 60 samples of artisanal fermented milk type Ben harvested from 20 farms in the wilaya of Bejaia. Phenotypic and biochemical identification was performed. In order to select strains of antibiotic-resistant S. aureus, an antibiotic susceptibility test was performed for cefotaxime and ceftazidime followed by an analysis of resistance phenotypes. 10 strains of Lactococcus were tested against strains of S. aureus resistant via the spot test. In order to determine the probable origin of the antibacterial activity of these strains, a test of the wells is carried out for the supernatants of lactic strains. The results obtained show that 50% of the ben samples are contaminated with S. aureus, in fact, 60 S.aureus strains are identified. The study of the sensitivity of these strains with respect to cefotaxime and ceftazidime made it possible to select 20 strains of S. aureus with a 32.62% strength of resistance. The analysis of the resistance phenotypes revealed the production of CTX-M-15 β-lactamases in 10 strains. The study of the antibacterial activity revealed zones of inhibition which vary between 15 and 35 mm. However, the well test showed that six strains of Lactococcus showed inhibitory zones that exceeded 15mm after pH neutralization of the supernatant. In conclusion., This high rate of resistance seems to reflect the inappropriate use of antibiotics. Nevertheless, the use of lactic bacteria strains of the Lactoccocus genus endowed with antibacterial activity could be an alternative for having artisanal products based on healthy raw milks.
Mounira Kara Ali
Boumardes University, Algeria
Title: Kinetic models and parameters estimation study of bioethanol production from inulin using P. caribbica
Biography:
Mounira Kara Ali has completed his PhD at the age of 30 years from Frères Mentouri Constantine 1 University and postdoctoral studies from the same university. He is the teatcher of biotechnology. He has published more than 20 papers in reputed journals.
Abstract:
Bioethanol serves as liquid fuel or gasoline enhancer in many countries in response to the progressive depletion of the world’s energetic resources. Production of bioethanol from inulin has been a subject of great interest for many years due to the large amount of existing and not completely developed technologies. The production of bioethanol from inulin, by the yeast Pichia caribbica as bioenergy source was investigated. The obtained results show that this strain was produced ethanol in two steps. Thus, it hydrolyzed 40g/l of inulin to 13.69 g/l and 7.4 g/l of fructose, after 24h, under aerobic and anaerobic conditions, respectively. The yields productions after 72h in these conditions were 0,31g of ethanol/g of inulin and 0,15g of ethanol/g of inulin, respectively. The growth kinetics and modeling of ethanol production from inulin by Pichia caribbica (KC977491) were studied in a batch system. Unstructured models were proposed using the logistic equation for growth, the Luedeking- Piret equation for ethanol production and modified Leudeking- Piret model for substrate consumption. Kinetic parameters (X0, μm, m, n, p and q) were determined by nonlinear regression, using Levenberg -Marquart method implemented in a Mathcad program. Since the production of ethanol was associated with P. caribbica cell growth, a good agreement between model predictions and experimental data was obtained. Indeed, significant R2 values of 0.91, 0.96, and 0.95 were observed for biomass, ethanol production and substrate consumption, respectively. Furthermore, analysis of variance (ANOVA) w as also used to validate the proposed models. According to the obtained results, the predicted kinetic values and experimental data agreed well. Finally, it is possible to predict the development of P. caribbica using these models.
Miyanou Rosales-Hurtado
Université de Nîmes, France
Title: Synthesis of new analogs of diaminopimelic acid (DAP) and lysine
Biography:
Miyanou Rosales-Hurtado has completed her Master’s degree in Molecular and Macromolecular Chemistry at University of Bordeaux, France and Internship course on G-quadruplexes at European Institute of Chemistry and Biology. She is currently pursuing her PhD at the University of Nimes, France.
Abstract:
Infections caused by multidrug-resistant bacteria represent one of the biggest challenges in the medical field. There is an urgent need to develop new antibacterial targets and antibacterial agents to combat multidrugresistance bacteria. For several years, the main target has been focused on the peptidoglycan biosynthesis pathway which provides a potential route to design novel antibiotic compounds. In fact, most bacteria require either lysine, or its biosynthetic precursor, Diaminopimelate Acid (DAP), as a component of the peptidoglycan layer of the cell wall. Nevertheless, DAP/Lysine is not present in mammals, thus, inhibitors of this pathway could provide potential antibacterial agents displaying low mammalian toxicity. In order to fight antibacterial resistance, our work focused on the design and synthesis of new analogs of diaminopimelic acid and lysine.
Melike Tepe
Gebze Technical University, Turkey
Title: Antibacterial effects of deoxsyhikonin produced by hairy root culture
Biography:
Melike Tepe completed a master in the Medical Microbiology Department at Istanbul University, now she is a Ph.D. candidate in Molecular Biology and Genetics at Gebze Technical University. During her PhD studies, she got a scholarship from the Higher Education Institution in the field of Sustainable Agriculture. She has published 1 paper, 2 poster, 1 oral presentation. Her main goal is to produce plant secondary metabolites that have anticancer and antibacterial effects and characterize them by applying several methods, namely FT-IR, HPLC, UV, NMR. She was worked in many science and nature festival which are funded by TUBÄ°TAK.
Abstract:
In nature, plants produce primary metabolites such as proline, glycose, etc. in order to improve its survival while under abiotic and biotic stress conditions, the plant produces secondary metabolites which are main classified of terpene, alkaloid and phenolic compound for adaptation in the environment. In Boraginaceae family, Echium italicum, Alkanna tinctoria, Lithospermum erytrorhizon plants produce phenolic compounds such as shikonin from hairy roots. Among them, Shikonin, which has antibacterial, anticancer and woundhealing activity, is still used in cosmetic and pharmaceutic industry in China and Japan. Hence, aim of this study concerns the investigation of antimicrobial effect of deoxyshikonin which was produced by hairy root culture under abiotic stress conditions. For antibacterial analysis, DMSO (dimethyl sulfoxide) was used as negative and chloramphenicol (C) utilized as positive control. According to our results, deoxyshikonin at 20 mg/ml showed in vitro antibacterial effect against Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 29213, Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa ATCC 15442.
- Clinical Microbiology | Bacterial and Viral Vaccines | Medical Virology, Clinical and Diagnostic Virology | Diagnosis and Treatment of Infectious Diseases | Bacterial and Viral Vaccines | Vector Borne and Zoonotic Infectious Diseases
Location: Renaissance polat Istanbul Hotel
Chair
Hsiu-Jung Lo
National Health Research Institutes, Taiwan
Session Introduction
Zohra Benfodda
Université De Nîmes, France
Title: Rational design, synthesis and antimicrobial properties of thiophene derivatives that inhibit bacterial histidine kinases
Biography:
Zohra Benfodda has completed her PhD in Organic Chemistry at Montpellier University. She is currently working as an Associate Professor at Nîmes University, France.
Abstract:
The emergence of multi-drug-resistant bacteria emphasizes the urgent need for novel antibacterial compounds targeting unique cellular processes. Two-component signal Transduction Systems (TCSs) are commonly used by bacteria to couple environmental stimuli to adaptive responses, are absent in mammals and are embedded in various pathogenic pathways. To attenuate these signaling pathways, we aimed to target the TCS signal transducer Histidine Kinase (HK) by focusing on their highly conserved Adenosine Triphosphate (ATP) binding domain. We used a structure-based drug design strategy that begins from an inhibitor-bound crystal structure and includes a significant number of structurally simplifying intuitive modifications to arrive at the simple achiral, biaryl target structures. Thus, ligands were designed, leading to a series of thiophene derivatives. These compounds were synthesized and evaluated in vitro against bacterial HKs. We identified eight compounds with significant inhibitory activities against these proteins, two of which exhibited broad-spectrum antimicrobial activity. The compounds were also evaluated as adjuvants for the treatment of resistant bacteria. One compound was found to restore the sensitivity of these bacteria to the respective antibiotics.
Biography:
Negar Zarif Zargarian Talasaz is a research student in Dr. Masih Daneshvari Hospital, Iran
Abstract:
Objective: To define the most common pathogens in patients with pleural empyema and find the specific antibiotics in order to treat patients more effectively.
Method: In this prospective analytic study all patients who admitted in Dr. Masih Daneshvari Hospital with the confirmed diagnosis of pleural empyema from April 2017 to 2018 were enrolled to our study. Sample of pleural fluid was sent to laboratory for Gram staining and aerobic and also anaerobic culture.
Results: 48 patients with pleural empyema including 40 men and 8 women with the mean age of 43.29 years (range of 5 to77) were studied. Cultures were positive in 6 patients (12.5%); a total of 4 microorganisms were isolated. Aerobic Gram-negative organisms were the most common bacteria in positive culture effusions (66.66%). In this study there were only 6 patients with positive cultures (12.5%), Two patients had Pseudomonas aeruginosa, Acinetobacter baumannii was cultured in two patients, Enterococcus sp., in one
patient and Streptococcus non group was cultured in one patient. Nine patients had positive Gram stain but there was not any growth in their cultures (all of them had rare Gram-positive cocci and two of them also had rare Gram-negative bacilli). The rest of the patients (33/48-68.75%) had negative Gram stain and cultures.
Conclusion: The number of patients who had positive culture was less than expected. We think that there might be a problem in sample collecting, sample transferring, culture providing or the improper usage of broad spectrum antibiotics before referring to hospital and taking the samples.