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.
- 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.