Day 1 :
Keynote Forum
Sasha Shafikhani
Rush University Medical Center, USA
Keynote: Delayed inflammatory response renders diabetic wound vulnerable to infection and microbiome shift toward pathogenic bacteria
Time : 10:35-11:15
Biography:
Sasha Shafikhani completed his undergraduate and PhD studies from University of California at Berkeley and postdoctoral studies from University of California at San Francisco. He serves on editorial board of several reputed journals. As a cellular microbiologist, his group focuses on immune dysregulation that renders diabetic wound vulnerable to infection and microbiome shift towards pathogenic bacteria. He also uses bacterial toxins to dissect epithelial cellular responses to pathogens, particularly Pseudomonas aeruginosa.
Abstract:
Enhanced bacterial infection and microbiome shift toward pathogenic bacteria are major co-morbidities that contribute to impaired healing in diabetic ulcer. The underlying reasons for the impaired infection control in diabetic wound remain poorly understood. We used the cutaneous full-thickness wound models in STZ-injected type 1 diabetic (T1D) rats and db/db T2D mice, to study the early dynamics of bacterial infection control in normal and diabetic wound tissues. Surprisingly, we have found that unlike chronic diabetic ulcers which suffer from persistent unresolving inflammation, the acute phase of inflammatory response- which is needed to counter invading pathogens early after injury- is significantly delayed in diabetic wounds, rendering these wounds susceptible to bacterial infection and healing impairment. Importantly, treatment with a pro-inflammatory chemokine jumpstarts inflammatory response and promotes healing in diabetic wound, indicating that inadequate inflammatory response early after injury in diabetic wound is just as harmful as the persistent inflammatory state that dominates these wounds as they become chronic. Our data further suggest that normal wound tissues express pathogen-specific antimicrobial peptides (ps-AMPs) that preferentially target pathogenic bacteria amongst commensals by recognizing specific virulence structure(s) that are only found in pathogenic bacteria. In contrast, pathogen-specific antimicrobial defenses are impaired in diabetic wounds, thus setting the stage for the microbiome shift toward pathogenic bacteria. We further show that the inability to control pathogenic bacteria leads to persistent inflammatory state and impaired healing in diabetic wound. We posit that inadequate chemokine expression in diabetic wound early after injury leads to delayed inflammatory response, which in turn results in reduced ps-AMPs, rendering diabetic wound vulnerable to infection with pathogenic bacteria, which exacerbate wound damage and drive diabetic wound toward persistent unresolving inflammatory state. We further propose that pro-inflammatory chemokine therapy may be used to jumpstart inflammatory response and restore antimicrobial defenses and stimulate healing in diabetic wound.
Keynote Forum
Marc G J Feuilloley
Normandy University, France
Keynote: Key role of cutaneous neuropeptides in skin-bacterial communication and virulence
Time : 11:55-12:35
Biography:
Marc G J Feuilloley has started his carrier in Cell Biology and Endocrinology an INSERM unit before tuning to Microbiology in 1996. When he joined his present research laboratory (LMSM) of which he is Director since 2008 and where he has developed Microbial Endocrinology. He is an Invited Professor at the Max Plank Institute, expert for national and international agencies. He is managing a parallel technology transfer society for cosmetic and pharmaceutical industry and is involved in the 1st world pole in cosmetic industry (Cosmetic-Valley). He is the author of 138 articles in international journals and more than 340 oral and poster communications in national and international conferences.
Abstract:
Skin is the principal neuroendocrine organ of the human body but it is also hosting its second microbial population. In skin, neuropeptides released by nerve terminals and cells diffuse in upper epidermal layers and sweat and it was recently shown that some of these peptides control skin bacteria virulence. Substance P, CGRP and Atrial Natriuretic Peptides (ANP, CNP) can be detected by bacteria between micro- and pico-molar concentrations through moonlighting (i.e. multifunctional) proteins, such as the Thermo Unstable Ribosomal Elongation Factor (EfTu), the chaperone DnaK or the amidase AmiC which are translocated to the bacterial surface through specific systems, including MscL mechanosensitive channels, and acquire environmental sensor functions. Substance P, CGRP, ANP and CNP are without effect on bacterial growth at physiological concentrations but modulate the cytotoxicity, virulence and biofilm formation activity of very different skin bacterial species, such as Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Pseudomonas fluorescens or Propionibacterium acnes. The effect of neuropeptides on bacteria is generally rapid (<5 min) but can last for days in the case of biofilm formation and leads to dramatic increases of virulence (>400%). Some of these neuropeptides, such as substance P and CGRP, have antagonistic effects. Others are only acting on one specific species, such as CGRP on S. epidermidis or have opposite actions, such as CNP on biofilm formation by S. aureus and P. acnes. The microbiote is integrating these host signals which determine its aggressivity and skin reaction. New dermo cosmetic products are now designed on this basis.
Keynote Forum
WC Yam
The University of Hong Kong, Hong Kong
Keynote: Rapid diagnosis of drug-resistant tuberculosis
Time : 12:35-13:15
Biography:
WC Yam is currently an Associate Professor in the Department of Microbiology, Faculty of Medicine from the University of Hong Kong. As a Clinical Scientist and Fellow Member of Royal College of Pathologists, he aims at rapid diagnosis of emerging infectious diseases including tuberculosis, drug resistant HIV-1, and SARS Corona virus which he had achieved major advancement for clinical application. More recently, he has been using molecular method to study drug resistant Mycobacterium tuberculosis and HIV. The studies on multi-drug resistant Mycobacterium tuberculosis and HIV-1 have included the development of Next Generation Sequencing.
Abstract:
Tuberculosis (TB) has reemerged as a global public health concern with an annual mortality of 3 millions. Coincident with the resurgence of tuberculosis, there is also an alarming increase of infections, due to multiple drug resistant tuberculosis (MDR-TB) organisms which are resistant to two or more of the first line anti-tuberculosis drugs including isoniazid and rifampicin. Recent threat has included extensively drug resistant tuberculosis (XDR-TB) defined as MDR-TB resistant to any fluoroquinolone and at least one second-line injectable drug. For rapid diagnosis of Mycobacterium tuberculosis (M. tb), Nucleic Acid Amplification assays such as PCR facilitates the adequate and timely management of antituberculosis therapy. Conventional antimycobacterial susceptibility testing remains the standard protocol to monitor drug resistant strains. More than 90% of rifampicin resistant M. tb has been shown to be caused by mutations inside the 81-bp rifampicin resistance determining region (RRDR) located in the center of the rpoB (encodes for b–subunit of the RNA polymerase) gene. In Hong Kong, PCR-sequencing of rpoB gene of M. tb isolates revealed mutations in codons D516V, H526D and S531L inside RRDR accounted for most rifampicin-resistant M. tb. PCR-sequencing also identified hotspot mutations at positions 90, 91 and 94 of gyrase A (gyrA) gene accounted for over 85% of Ofloxacin-resistant M. tb in Hong Kong. For isoniazid resistance, multiple allele-specific PCRs (MAS-PCRs) assays targeting the mutations in codon 315 of katG gene and the 15th nucleotide preceding the mabA-inhA operon successfully identified 60-75% isoniazid-resistant M. tb in clinical specimens. Using PCR-sequencing, novel mutations associated with rifampicin and Ofloxacin resistance were also identified among treatment experienced patients. Current study on massive parallel targeted sequencing (MPTS) for simultaneous prediction of drug susceptibility in Mycobacterium tuberculosis from respiratory specimens shows promising results. The cost-effectiveness of development, introduction and availability of these methods for rapid diagnostics improves public health control and early initiation of anti-tuberculosis therapy.
- Day 01
Session Introduction
Carole Creuzenet
The University of Western Ontario, Canada
Title: Disulfide bond formation in gastric pathogen Helicobacter pylori: An Achillae’s heel for secretion of pro-inflammatory virulence proteins
Time : 15:10-15:35
Biography:
Carole Creuzenet has completed her PhD in Biochemistry at the University of Nantes and The National Institute for Agronomical Research (France). She has completed her Post-doctoral studies at the Massachusetts Institute of Technology (USA) and the University of Guelph (Canada). She is Associate Professor at the University of Western Ontario (London, Canada) where her lab focuses on virulence factors from bacterial gastrointestinal pathogens such as Campylobacter jejuni, Helicobacter pylori and Yersinia pseudotuberculosis. Her focus is on glycolipids and glycoproteins as well as on novel secreted proteins and their folding partners. She has published 38 papers in reputed journals.
Abstract:
H. pylori causes gastritis, gastric ulcers and cancers but the mechanisms of virulence are not fully understood. It produces secreted proteins which may play a role in eliciting gastric inflammation, including the helicobacter cysteine rich protein HcpE (HP0235) whose biological function is unknown. Our goal was to investigate if HcpE is secreted by H. pylori and is involved in host/pathogen interactions, and identify components essential for its production. Using a combination of anti-HcpE ELISA and western blots, knockout mutagenesis, phenotypic analyses and biochemical assays, we demonstrate that HcpE is secreted by many strains as a soluble protein and in association with outer membrane vesicles. We show that infected patients produce anti-HcpE antibodies, indicating in situ HcpE production. We show that HcpE comprises many disulfide bonds and identify DsbK (HP0231) as a folding factor necessary for HcpE production, and show that recombinant DsbK can refold unprocessed, reduced HcpE in vitro. This highlights the first biologically relevant substrate for DsbK. Furthermore, we show that DsbK has disulfide bond (Dsb) forming activity on reduced lysozyme and has DsbA-like activity upon expression in E. coli, despite its similarity with DsbG. Also, we show a role of DsbK in redox homeostasis in H. pylori. Finally, we show an important role for DsbK and HcpE in host-pathogen interactions, including murine gastric colonization and pro-inflammatory cytokine production in human gastric explants and in murine splenocytes. Both proteins will be investigated as therapeutic targets to treat H. pylori infections and prevent gastric ulcers and cancers.
Louis Bengyella
Vaal University of Technology, South Africa
Title: Proteomics insight into temperature-dependent pathogenicity of Cochliobolus lunatus during invasion of potato
Time : 16:15-16:40
Biography:
Louis Bengyella has expertise in fungal-plant, virus-plant and insect-plant interactions and he is interested in plant health and increased crop production. He has completed his PhD at the University of Burdwan, India and Post-doctoral studies from the University of the Witwatersrand School of Cell and Molecular Biology and Department of Biotechnology in Vaal University of Technology, South Africa. He has published more than 30 papers in reputed journals and has been serving as an Editorial Board Member for Springer, Elsevier, Science alert and Academic publishers.
Abstract:
It is established that Cochliobolus lunatus secretes a myriad of proteins to break plant primary defense (i.e. cuticle and cell walls) and degrade complex carbohydrates for nutrients acquisition. Many larger secreted proteins with potential roles in pathogenicity include predicted cutinases, peptidases, glucanases, fungal transporters belonging to the major facilitator super-family (MFS), and ATP-binding cassette (ABC) group proteins, and carbohydrates active enzymes. But major physiological pathways affected in potato during C. lunatus colonization are unknown during incitement of brown-to-black leaf spot disease. Using proteomics approach, it is shown that C. lunatus significantly (P<0.05) suppressed the host functional proteome at 96 h after infection, predominantly affecting the expression of ribulose bisphosphate carboxylase enzyme, plastid aldolase enzyme, alcohol dehydrogenase 2 and photosystem II protein prior to the formation of brown-to-black leaf spot disease. Robust host–response was observed at 24 h after infection associated by 307 differentially expressed peptide spots concurring with the active phase of production of infectious hyphae. Importantly, C. lunatus differentially down-regulate StNPR1 transcript by 8.19-fold by 24 h after infection. We also observed that C. lunatus transiently down-regulate the expression of StNPR1 at the onset of infection. Put together, the infection negatively affects the expression of proteome modules involved in photosynthesis, carbon fixation and light assimilation. This study contributes towards better understanding of the mechanism underlining the invasion strategies of C. lunatus.
Arghavan Alisoltani
Vaal University of Technology, South Africa
Title: Core-bacterial composition and function of ruminant animals based on integrative analysis of metagenomics data
Time : 16:40-17:05
Biography:
Arghavan Alisoltani has her expertise in Computational Biology and Genetic Studies of Model Plants and Animals. She has completed her PhD at the Shahrekord University, Iran. She is currently pursuing her Post-doctoral research in Department of Biotechnology, The Vaal University of Technology, South Africa. Her scientific productivity is publishing several research papers in high ranked journals.
Abstract:
Metagenomic analysis based on high throughput sequencing is a newly developed approach, widely been applied to identify the microbial composition and diversity of ruminant animals. Despite attempts have been done to depict the microbial composition of rumen in various animals, the little attention has been devoted to finding core-bacterial composition of ruminant animals, pathogenic species. Due to integrative analysis of different datasets is expected to be more informative, in the present study, microbial composition of different animals was evaluated, using integrative analysis of metagenomic data aim to obtain holistic overview of core-bacterial population. In total, 12 datasets were analyzed using the CLC Microbial Genomics Module in CLC Genomics Workbench 9.1 (CLC Bio, Qiagen). SILVA.123 database (97%) was used for detection of operational taxonomic units (OTUs) with the similarity percentage of 97%. In total 3,471 OTUs are found based on SILVA.123 database. Bacteroidetes was the most abundant phylum across all samples (42.57%), followed by Firmicutes (36.25%), and Proteobacteria (13.43%). In addition, Prevotella1 (21.4%), Rikenellaceae RC9 gut group (5.9), and Veillonellaceae UCG-001 (4.5%) were recorded as dominant genera across all studied animals. Functional profiling of OTUs has been provided good clues about the potential role of bacterial population in ruminants. We found that high amounts of OTUs were related to human diseases such as different cancers. Taken together, our findings provided an overall insight about the core-bacterial composition and function of ruminant animals, human disease related bacteria.