Day 1 :
Keynote Forum
Mohannad Al Saghir
Ohio University, USA
Keynote: Risk Awareness of Disease and Infection Undergraduate Study (RADIUS) Combining Teaching, Research and Community Service
Time : 10:15-10:45
Biography:
Mohannad Al-Saghir has joined Ohio University in 2006 and holds a PhD in Biology with Microbiology and Plant Biology focus. His research is centered on microbial
evolution, medical microbiology and plant systematics and evolution. He is an Associate Professor of Biological Sciences at Ohio University Zanesville, USA. His
most recent publication is “Immunohistochemical Localization of Aspergillus and p53 in human lung tissues” published in American Journal of Molecular Biology
in 2015.
Abstract:
RADIUS (Risk Awareness of Disease and Infection Undergraduate Study) is a multipurpose project aimed at using modern
biotechnology to investigate the presence of parasitic and microbial contaminants in public parks, playgrounds and public
swimming pools in Zanesville, Ohio and provide Ohio University students with a superior learning experience through a
field-based, hands-on and problem-based curriculum centered on scientific and critical thinking. Launched in the Fall-2007,
RADIUS involved over 100 OUZ undergraduate students who collected swab and soil samples from public places and analyzed
them in the lab using both biochemical and molecular approaches. Many bacterial and fungal pathogens have been identified.
The project exposes students to modern biotechnology and its application to identify the potential environmental and
epidemiological risk factors and the dynamics of infectious agents in the local community. The RADIUS activities represent a
pilot model for incorporating biotechnology in teaching and learning, foster student-faculty research while providing service
to the community. Initial feedback and outcomes indicated the value of this form of improved undergraduate learning and
community service.
Keynote Forum
Ruslan Afasizhev
Boston University School of Dental Medicine, USA
Keynote: Uridylation-induced RNA degradation in mitochondria of trypanosomes: mechanisms, targets and evolution
Time : 11:05-11:35
Biography:
Ruslan Afasizhev has completed his PhD from Institute of Molecular Biology, Russian Academy of Sciences. He is a Professor of Molecular and Cell Biology at
Boston University Medical Campus, USA. He has published more than 50 papers in high ranking journals.
Abstract:
Massive U-insertion/deletion mRNA editing in mitochondria of trypanosomes inspired earlier efforts to discover enzymes
responsible for RNA uridylation. Studies of RNA editing ultimately led to identification of two terminal uridyltransferases
(TUTases): RNA editing TUTase 1 (RET1) and RNA editing TUTase 2 (RET2). Subsequent work demonstrated that RET2
functions as subunit of the RNA editing core complex and is responsible for internal mRNA editing. Conversely, RET1 was
implicated in 3' modification of mRNA, rRNA and guide RNAs. Recently, we identified a protein complex composed of RET1
TUTase, DSS1 3'-5' exonuclease and three additional subunits. This complex, termed mitochondrial 3' processome (MPsome),
is responsible for primary uridylation of ~800-nt gRNA precursors, their processive degradation to a mature size of 40-60
nucleotides and secondary U-tail addition. Both strands of the gRNA gene are transcribed into sense and antisense precursors
of similar lengths. Head-to-head hybridization of these transcripts blocks symmetrical 3'-5' degradation at a fixed distance
from the double-stranded region. Together, our findings suggest a model in which gRNA is derived from the 5' extremity of
a primary molecule by uridylation-induced, antisense transcription-controlled 3'-5' exonucleolytic degradation. Remarkably,
we also established that MPsome-catalyzed 3'-5' degradation also represents the major pathway for mRNA processing and
degradation. These finding poses a logistical challenge to the established paradigm of multicistronic mitochondrial transcription
and raises the questions of mRNA 5' end modification and 3' end definition. We will discuss potential existence of gene specific
promoters and the role of MERS1 NUDIX hydrolase in mRNA 5' processing and stabilization. We will also present data
demonstrating that, in contact to antisense RNA-based 3' end definition of gRNAs, the mature 3' ends of pre-mRNAs are
generated by protein-based mechanism that blocks the MPsome and stimulates mRNA polyadenylation.
Keynote Forum
Mette Kolpen
University of Copenhagen, Denmark
Keynote: Enhancement of the bactericidal activity of antibiotics in hypoxic biofilms as seen in patients with chronic pulmonary disease.
Time : 11:35-12:00
Biography:
Mette Kolpen has completed her PhD from University of Copenhagen and is currently a Postdoctoral Fellow at University of Copenhagen, Germany. She has published 13
scientific articles in peer-reviewed international journals and books. She has during the previous 6 years demonstrated O2 depletion in the endobronchial mucus of cystic
fibrosis (CF) patients.
Abstract:
Pseudomonas aeruginosa lung infection is among the most severe complication in patients with chronic obstructive pulmonary
disease (COPD) and cystic fibrosis (CF). CF related pulmonary infection is characterized by antibiotic-tolerant biofilms in the
endobronchial mucus with zones of oxygen (O2) depletion mainly due to polymorphonuclear leukocyte (PMN) activity. Despite
anoxic conditions, the flexible metabolism of P. aeruginosa growing in biofilms allows this pathogen to obtain energy for growth by
denitrification as demonstrated by production of nitrous oxide in CF sputum samples. While the exact mechanisms affecting antibiotic
effectiveness on biofilms remain unclear, accumulating evidence suggests that the efficiency of several bactericidal antibiotics such
as ciprofloxacin is enhanced by stimulation of the aerobic respiration of pathogens and that lack of O2 increases their tolerance. Reoxygenation
of O2- depleted biofilms may thus improve susceptibility to ciprofloxacin possibly by restoring aerobic respiration. Such
strategy was then tested using re-oxygenation of O2- depleted P. aeruginosa strain PAO1 agarose embedded biofilms by hyperbaric
O2 treatment (HBOT) enhancing the diffusive supply for aerobic respiration during ciprofloxacin treatment. The demonstration of
enhanced bactericidal activity of ciprofloxacin in P. aeruginosa biofilm during re-oxygenation by hyperbaric O2 treatment (HBOT) is
indeed a proof-of-principle study that may translate into improved treatment of both CF and COPD patients.
Keynote Forum
Ella Cullen
University of Stirling, United Kingdom
Keynote: Ultra-fast drug resistance predictions from NGS sequence data using Cloud Computing
Time : 12:00-12:25
Biography:
Ella Cullen is a graduate Trinity College Dublin’s School of Genetics. She has worked on several projects relating to human disease, including psoriasis and
neurodevelopmental disorders. She now works with NSilico Life Science. NSilico’s focus is on the development of easy-to-use Ella Cullen clinical and bioinformatics
software which can significantly accelerate the research process. Ella works with the company’s research teams, which have a particular focus on infectious disease and
cancer. She also works on forming collaborative projects with labs and companies around the world.
Abstract:
Rapid and accurate prediction of drug resistance in pathogens is a growing need, affecting patient care and emerging personal
medicine. Bacterial genome sequencing has been introduced in many hospitals as a cheaper alternative to gene targeted
sequencing and PCR, but many handling issue remain to be overcome. Here, we address some of the challenges, by offering a cloudbased
solution that while keeping security and privacy at the heart of the development allows remote management of large datasets,
and ultra-fast drug resistance predictions without the need for local installation, maintenance or bioinformatics knowledge. Validated
using literature references, we have implemented a profiler that reconstitutes (from raw sequences) the genes associated with resistance
and produces an ultra-fast and accurate prediction of drug resistance. If raw sequences are available, regardless of the platform
used, the profiler will generate a prediction within minutes, in contrast to other solutions which typically require hours of analysis
time and interpretation. The profiler currently focuses on Mycobacterium tuberculosis and 9 key drugs, including Aminoglycosides
(Kanamycin, Capreomycin, Amikacin, Viomycin), Ethambutol, Ethionamide, Fluoroquinolones, Isoniazid, Para-Aminosalisylic
Acid, Pyrazinamide, Rifampicin, and Streptomycin.
Keynote Forum
Arinze Okoli
Genok - Centre for Biosafety, Norway
Keynote: Application of Proteomics in the study of Microbial Physiology: taking advantage of changes in the microbe’s normal functions under stress conditions
Time : 13:25-13:50
Biography:
Arinze Okoli is associated with GenØk –Centre for Biosafety, Tromsø, Norway. He has published several papers in reputed journals. He is committed to highest standards
of excellence and it proves through her authorship of many books. His research interests include Microbiology.
Abstract:
Stress conditions cause microorganisms to adjust their normal functions to counter the deleterious effects of the stress. This
includes modulating relevant proteins in response to the stress. In our studies, we seek to decipher the message inherent in
the picture painted by the network of the modulated proteins, with the aim of understanding the physiology of the bacteria and
viruses. For example, under exposure to sub-lethal concentrations of the herbicide, glyphosate, and its breakdown product, amino
methyl phosphonic acid (AMPA), E .coli upregulated 18 and downregulated 14 proteins under glyphosate stress. Under AMPA
stress, the bacterium upregulated 32 and downregulated 8 proteins. E. faecalis upregulated 67 and downregulated 16 proteins under
glyphosate stress, but upregulated 172 and down-regulated 104 proteins under AMPA stress. For E. coli, majority of the regulated
proteins under glyphosate and AMPA stress where transport, stress response and nitrate metabolic proteins. Exposure of Helicobacter
hepaticus under the stress of bile –an antimicrobial agent which is produced in the liver, concentrated in the gallbladder and released
into the gut during digestion of fatty foods, resulted in the modulation of different proteins. In bovine, porcine or human bile, the
bacterium modulated differently the expression of several virulence determinants including the cytolethal distending toxin (CDT),
urease, superoxide dismutase, flagellin and ferritin. For example, superoxide dismutase was downregulated in the three types of bile;
CDT was downregulated in bovine and human bile, but was unaffected by porcine bile; urease was downregulated in bovine bile,
upregulated in porcine bile and unaffected in human bile. The data suggested that bile serves as an environmental cue for protein
expression by H. hepaticus, and may modulate its virulence factors. Genetic modification of organisms, e.g. insertion of unrelated
foreign gene into the genome of an organism (transgenesis) also can be considered a type of stress given that the organisms are forced
to adapt to the effects of the genetic manipulation. The introduction of the haemagglutinin and nucleoprotein genes of the H1N1
influenza virus into the genome of Modified Vaccinia virus Ankara resulted in the modulation of 32 virus encoded proteins that are
involved in various pathways of the virus replication. Overall, application of proteomics in conjunction with other complimentary
molecular biology tools, has enabled us to contribute towards understanding the physiology of these organism.
Keynote Forum
Khalid Habib
Baghdad-University, Iraq
Keynote: Influence of Temperature and pH on the Growth of Lactobacillus reuteri ATCC 23272 using Optical Density assay
Time : 13:50-14:15
Biography:
KhalidA. Habeb currently working as Professor in microbiology Department of Biology / College of Science for Women / University of Baghdad, Iraq.
Abstract:
Background & Aim: Lactobacillus reuteri, which is a normal flora in intestine and the female genital tract, can be used as probiotic
bacteria to give health benefits. The aim of this study is to evaluate the effect of two physiological factors (temperature and pH) on the
growth of Lactobacillus reuteri ATCC 23272.
Method: In this study, Lactobacillus reuteri ATCC 23272 was cultivated in MRS broth and adjusted to four different initial pH
values and incubated at four different temperatures degrees. For all of the resulted 16 subgroups (each subgroup consists of 10 broth
samples), initial optical density was adjusted to (1.4) at 540 nm. After incubation, the final optical density and pH were measured and
the data were collected and analyzed statistically.
Results: The incubation temperature and the initial pH of the culture medium had a significant effect on the growth rate of Lactobacillus
reuteri ATCC 23272. The optimal conditions for the growth were (Temp. 30oC, pH 6.5) with an optical density around (1.9297) at 540
nm, while the lowest growth rate was at (Temp. 25oC, pH 3.5) with an optical density around (0.0002) at 540 nm.
Conclusion: The physiological environment has a great influence on the growth rate of Lactobacillus reuteri ATCC 23272.
Keynote Forum
Miklos Fuzi
Semmelweis University, Hungary
Keynote: Diverse fitness associated with resistance to fluoroquinolones influenced the clonal dynamics of various multiresistant pathogens
Time : 14:15-14:40
Biography:
Miklos Fuzi has completed his PhD in 2001 and has been engaged in the investigation of clonality and antibiotic resistance during the last 15 years. He has published 38
papers in reputed journals. He is an Associate Professor at Semmelweis University, Budapest, Hungary.
Abstract:
Fitness cost associated with resistance to fluoroquinolones was recently shown to vary across clones of methicillin-resistant
Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae. The resulting
dissimilar fitness should have influenced the clonal dynamics and thereby the rates of resistance for these pathogens. Moreover, a
similar mechanism was recently proposed for the emergence of the H30 and H30R lineages of ESBL-producing E. coli and the major
international clone (ribotype 027) of Clostridium difficile. The overwhelming part of the available epidemiological data supports
the connection. An ability to develop favorable mutations in the gyrase and topoisomerase IV genes seems to be a prerequisite for
pathogens to retain fitness while showing high-level resistance to fluoroquinolones. Moreover, the mechanism was observed to select
for the CTX-M-15 type ESBL in K. pneumoniae that may account for the widespread dissemination of this enzyme. The findings
suggest that the use of fluoroquinolones as a function of clonal distribution could ameliorate the state of antibiotic resistance. When
the proportions of multiresistant clones influenced by fluoroquinolones are low the use of these antibiotics remains highly beneficial.
However when their proportion increases the consumption of fluoroquinolones should transiently be reduced.
Keynote Forum
Inna Afasizheva
Boston University School of Dental Medicine, USA
Keynote: Pentatricopeptide repeat (PPR) RNA binding proteins regulate mRNA processing in mitochondria of Trypanosoma brucei
Time : 15:05-15:30
Biography:
Inna Afasizheva has received her PhD from Institute of Molecular Biology, Russian Academy of Sciences. She is a Professor of Molecular and Cell Biology at Boston
University Medical Campus, USA. She has published more than 30 papers in high ranking journals.
Abstract:
The majority of mitochondrial pre-mRNAs in trypanosomes undergo massive uridine insertion/deletion editing to create
open reading frames. Although required, editing is not sufficient to produce most of translationally-competent mitochondrial
mRNAs. Pre and post-editing adenylation and uridylation reactions are essential for mRNA stabilization and ribosome recruitment.
Adenylation prior to editing by KPAP1 poly(A) polymerase stabilizes transcripts that are edited beyond few initial sites, while A/Utailing
by KPAP1 and RET1 TUTase commits the fully-edited mRNA for translation. Temporal separation of these events suggests
that a mechanism must exist to prevent premature A/U-tailing and to couple the completion of editing with A/U-tailing. To identify
protein factors responsible for mRNA 3' modification and coordination with editing, we built a comprehensive protein interactions
network of mRNA polyadenylation, editing and translation complexes. RNAi knockdowns, in vivo RNA binding sites mapping and
in vitro reconstitution indicate that pre-mRNA is initially stabilized by binding of a specific pentatricopeptide repeat-containing
protein (PPR). This factor, termed Kinetoplast Polyadenylation Factor 3 (KPAF3), defines the 3' end of pre-edited mRNA by impeding
mRNA degradation by the 3' processome. KPAF3 also stimulates KPAP1’s poly(A) polymerase activity to ensure that only A-tailed
mRNAs proceed through the editing pathway. We also identified a distinct PPR factor, KPAF4, that binds to a junction between
the mRNA and poly(A) tail and blocks premature A/U-tailing. These findings will be presented in a context of integrating editing,
polyadenylation and uridylation processes with mRNA selection by the ribosome.
- Industrial Microbiology | Microbial Screening and Physiology|Microbial Diseases|Advanced Microbial Genetics|Microbes and Environments|Microbial Metabolism|
Chair
Mohannad Al Saghir
Ohio University ,USA
Co-Chair
Ruslan Afasizhev
Boston University School of Dental Medicine,USA
Session Introduction
Mette Kolpen
University of Copenhagen, Denmark
Title: Enhancement of the bactericidal activity of antibiotics in hypoxic biofilms as seen in patients with chronic pulmonary disease
Biography:
Mette Kolpen has completed her PhD from University of Copenhagen and is currently a Postdoctoral Fellow at University of Copenhagen, Germany. She has published 13
scientific articles in peer-reviewed international journals and books. She has during the previous 6 years demonstrated O2 depletion in the endobronchial mucus of cystic
fibrosis (CF) patients.
Abstract:
Pseudomonas aeruginosa lung infection is among the most severe complication in patients with chronic obstructive pulmonary
disease (COPD) and cystic fibrosis (CF). CF related pulmonary infection is characterized by antibiotic-tolerant biofilms in the
endobronchial mucus with zones of oxygen (O2) depletion mainly due to polymorphonuclear leukocyte (PMN) activity. Despite
anoxic conditions, the flexible metabolism of P. aeruginosa growing in biofilms allows this pathogen to obtain energy for growth by
denitrification as demonstrated by production of nitrous oxide in CF sputum samples. While the exact mechanisms affecting antibiotic
effectiveness on biofilms remain unclear, accumulating evidence suggests that the efficiency of several bactericidal antibiotics such
as ciprofloxacin is enhanced by stimulation of the aerobic respiration of pathogens and that lack of O2 increases their tolerance. Reoxygenation
of O2- depleted biofilms may thus improve susceptibility to ciprofloxacin possibly by restoring aerobic respiration. Such
strategy was then tested using re-oxygenation of O2- depleted P. aeruginosa strain PAO1 agarose embedded biofilms by hyperbaric
O2 treatment (HBOT) enhancing the diffusive supply for aerobic respiration during ciprofloxacin treatment. The demonstration of
enhanced bactericidal activity of ciprofloxacin in P. aeruginosa biofilm during re-oxygenation by hyperbaric O2 treatment (HBOT) is
indeed a proof-of-principle study that may translate into improved treatment of both CF and COPD patients.
Ella Cullen
University of Stirling, United Kingdom
Title: Ultra-fast drug resistance predictions from NGS sequence data using Cloud Computing
Biography:
Ella Cullen is a graduate Trinity College Dublin’s School of Genetics. She has worked on several projects relating to human disease, including psoriasis and
neurodevelopmental disorders. She now works with NSilico Life Science. NSilico’s focus is on the development of easy-to-use Ella Cullen clinical and bioinformatics
software which can significantly accelerate the research process. Ella works with the company’s research teams, which have a particular focus on infectious disease and
cancer. She also works on forming collaborative projects with labs and companies around the world.
Abstract:
Rapid and accurate prediction of drug resistance in pathogens is a growing need, affecting patient care and emerging personal
medicine. Bacterial genome sequencing has been introduced in many hospitals as a cheaper alternative to gene targeted
sequencing and PCR, but many handling issue remain to be overcome. Here, we address some of the challenges, by offering a cloudbased
solution that while keeping security and privacy at the heart of the development allows remote management of large datasets,
and ultra-fast drug resistance predictions without the need for local installation, maintenance or bioinformatics knowledge. Validated
using literature references, we have implemented a profiler that reconstitutes (from raw sequences) the genes associated with resistance
and produces an ultra-fast and accurate prediction of drug resistance. If raw sequences are available, regardless of the platform
used, the profiler will generate a prediction within minutes, in contrast to other solutions which typically require hours of analysis
time and interpretation. The profiler currently focuses on Mycobacterium tuberculosis and 9 key drugs, including Aminoglycosides
(Kanamycin, Capreomycin, Amikacin, Viomycin), Ethambutol, Ethionamide, Fluoroquinolones, Isoniazid, Para-Aminosalisylic
Acid, Pyrazinamide, Rifampicin, and Streptomycin.
Arinze Okoli
Genok - Centre for Biosafety, Norway
Title: Application of Proteomics in the study of Microbial Physiology: taking advantage of changes in the microbe’s normal functions under stress conditions
Biography:
Arinze Okoli is associated with GenØk –Centre for Biosafety, Tromsø, Norway. He has published several papers in reputed journals. He is committed to highest standards
of excellence and it proves through her authorship of many books. His research interests include Microbiology.
Abstract:
Stress conditions cause microorganisms to adjust their normal functions to counter the deleterious effects of the stress. This
includes modulating relevant proteins in response to the stress. In our studies, we seek to decipher the message inherent in
the picture painted by the network of the modulated proteins, with the aim of understanding the physiology of the bacteria and
viruses. For example, under exposure to sub-lethal concentrations of the herbicide, glyphosate, and its breakdown product, amino
methyl phosphonic acid (AMPA), E .coli upregulated 18 and downregulated 14 proteins under glyphosate stress. Under AMPA
stress, the bacterium upregulated 32 and downregulated 8 proteins. E. faecalis upregulated 67 and downregulated 16 proteins under
glyphosate stress, but upregulated 172 and down-regulated 104 proteins under AMPA stress. For E. coli, majority of the regulated
proteins under glyphosate and AMPA stress where transport, stress response and nitrate metabolic proteins. Exposure of Helicobacter
hepaticus under the stress of bile –an antimicrobial agent which is produced in the liver, concentrated in the gallbladder and released
into the gut during digestion of fatty foods, resulted in the modulation of different proteins. In bovine, porcine or human bile, the
bacterium modulated differently the expression of several virulence determinants including the cytolethal distending toxin (CDT),
urease, superoxide dismutase, flagellin and ferritin. For example, superoxide dismutase was downregulated in the three types of bile;
CDT was downregulated in bovine and human bile, but was unaffected by porcine bile; urease was downregulated in bovine bile,
upregulated in porcine bile and unaffected in human bile. The data suggested that bile serves as an environmental cue for protein
expression by H. hepaticus, and may modulate its virulence factors. Genetic modification of organisms, e.g. insertion of unrelated
foreign gene into the genome of an organism (transgenesis) also can be considered a type of stress given that the organisms are forced
to adapt to the effects of the genetic manipulation. The introduction of the haemagglutinin and nucleoprotein genes of the H1N1
influenza virus into the genome of Modified Vaccinia virus Ankara resulted in the modulation of 32 virus encoded proteins that are
involved in various pathways of the virus replication. Overall, application of proteomics in conjunction with other complimentary
molecular biology tools, has enabled us to contribute towards understanding the physiology of these organism.
Khalid Habib
Baghdad-University, Iraq
Title: Influence of Temperature and pH on the Growth of Lactobacillus reuteri ATCC 23272 using Optical Density assay
Biography:
KhalidA. Habeb currently working as Professor in microbiology Department of Biology / College of Science for Women / University of Baghdad, Iraq.
Abstract:
Background & Aim: Lactobacillus reuteri, which is a normal flora in intestine and the female genital tract, can be used as probiotic
bacteria to give health benefits. The aim of this study is to evaluate the effect of two physiological factors (temperature and pH) on the
growth of Lactobacillus reuteri ATCC 23272.
Method: In this study, Lactobacillus reuteri ATCC 23272 was cultivated in MRS broth and adjusted to four different initial pH
values and incubated at four different temperatures degrees. For all of the resulted 16 subgroups (each subgroup consists of 10 broth
samples), initial optical density was adjusted to (1.4) at 540 nm. After incubation, the final optical density and pH were measured and
the data were collected and analyzed statistically.
Results: The incubation temperature and the initial pH of the culture medium had a significant effect on the growth rate of Lactobacillus
reuteri ATCC 23272. The optimal conditions for the growth were (Temp. 30oC, pH 6.5) with an optical density around (1.9297) at 540
nm, while the lowest growth rate was at (Temp. 25oC, pH 3.5) with an optical density around (0.0002) at 540 nm.
Conclusion: The physiological environment has a great influence on the growth rate of Lactobacillus reuteri ATCC 23272.
Miklos Fuzi
Semmelweis University, Hungary
Title: Diverse fitness associated with resistance to fluoroquinolones influenced the clonal dynamics of various multiresistant pathogens
Biography:
Miklos Fuzi has completed his PhD in 2001 and has been engaged in the investigation of clonality and antibiotic resistance during the last 15 years. He has published 38
papers in reputed journals. He is an Associate Professor at Semmelweis University, Budapest, Hungary.
Abstract:
Fitness cost associated with resistance to fluoroquinolones was recently shown to vary across clones of methicillin-resistant
Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae. The resulting
dissimilar fitness should have influenced the clonal dynamics and thereby the rates of resistance for these pathogens. Moreover, a
similar mechanism was recently proposed for the emergence of the H30 and H30R lineages of ESBL-producing E. coli and the major
international clone (ribotype 027) of Clostridium difficile. The overwhelming part of the available epidemiological data supports
the connection. An ability to develop favorable mutations in the gyrase and topoisomerase IV genes seems to be a prerequisite for
pathogens to retain fitness while showing high-level resistance to fluoroquinolones. Moreover, the mechanism was observed to select
for the CTX-M-15 type ESBL in K. pneumoniae that may account for the widespread dissemination of this enzyme. The findings
suggest that the use of fluoroquinolones as a function of clonal distribution could ameliorate the state of antibiotic resistance. When
the proportions of multiresistant clones influenced by fluoroquinolones are low the use of these antibiotics remains highly beneficial.
However when their proportion increases the consumption of fluoroquinolones should transiently be reduced.
Marie Joelle Virolle
University Paris Sud, France
Title: Strong antibiotic production is correlated with an oxidative metabolism in Streptomyces
Biography:
Marie Joelle Virolle is associated with University of Paris-Sud, France. Marie Joelle has published several papers in reputed journals. Marie Joelle is committed to highest
standards of excellence and it proves through the authorship of many books. Marie Joelle research interests include Systems Biology, Molecular Biology and Microbiology.
Abstract:
The Streptomyces genus is well known for its outstanding ability to produce secondary metabolites of great interest for human kind
such as antibiotics. Antibiotic biosynthesis occurs in the periods of slow or no growth and is triggered by phosphate limitation, a
condition known to be correlated with energetic stress. However, the metabolic changes underlying the transition between primary
and secondary metabolism remains largely elusive. Comparative physiological and proteomic studies of two closely related model
strains, S. lividans and S. coelicolor, weak and strong producers of the same antibiotics, respectively, were carried out. These studies
clarified for the first time the nature of the metabolic transition between primary and secondary metabolism. This switch triggered
by energetic stress results from a transition from a glycolytic to an oxidative metabolism in order to restore the energetic balance of
the cell. Our results indicate that in condition of energetic stress, the acetyl-CoA generated by glycolysis, rather than being stored as
lipids of the triacylglycerol family, is used to fuel the Krebs cycle, more favorable than glycolysis for energy generation. Krebs cycle
yields molecules that are direct precursors of amino acids used for peptidyl antibiotic biosynthesis as long as sufficient nitrogen is
available. When nitrogen becomes limiting, acetyl-CoA would then be used for direct biosynthesis of polyketide antibiotics. A tool
based on these novel principles was conceived and implemented to enhance the expression of the numerous biosynthetic pathways
present in the Streptomyces genomes.
Inna Afasizheva
Boston University School of Dental Medicine, USA
Title: Pentatricopeptide repeat (PPR) RNA binding proteins regulate mRNA processing in mitochondria of Trypanosoma brucei
Biography:
Inna Afasizheva has received her PhD from Institute of Molecular Biology, Russian Academy of Sciences. She is a Professor of Molecular and Cell Biology at Boston
University Medical Campus, USA. She has published more than 30 papers in high ranking journals.
Abstract:
The majority of mitochondrial pre-mRNAs in trypanosomes undergo massive uridine insertion/deletion editing to create
open reading frames. Although required, editing is not sufficient to produce most of translationally-competent mitochondrial
mRNAs. Pre and post-editing adenylation and uridylation reactions are essential for mRNA stabilization and ribosome recruitment.
Adenylation prior to editing by KPAP1 poly(A) polymerase stabilizes transcripts that are edited beyond few initial sites, while A/Utailing
by KPAP1 and RET1 TUTase commits the fully-edited mRNA for translation. Temporal separation of these events suggests
that a mechanism must exist to prevent premature A/U-tailing and to couple the completion of editing with A/U-tailing. To identify
protein factors responsible for mRNA 3' modification and coordination with editing, we built a comprehensive protein interactions
network of mRNA polyadenylation, editing and translation complexes. RNAi knockdowns, in vivo RNA binding sites mapping and
in vitro reconstitution indicate that pre-mRNA is initially stabilized by binding of a specific pentatricopeptide repeat-containing
protein (PPR). This factor, termed Kinetoplast Polyadenylation Factor 3 (KPAF3), defines the 3' end of pre-edited mRNA by impeding
mRNA degradation by the 3' processome. KPAF3 also stimulates KPAP1’s poly(A) polymerase activity to ensure that only A-tailed
mRNAs proceed through the editing pathway. We also identified a distinct PPR factor, KPAF4, that binds to a junction between
the mRNA and poly(A) tail and blocks premature A/U-tailing. These findings will be presented in a context of integrating editing,
polyadenylation and uridylation processes with mRNA selection by the ribosome.