Antibiotics

Event Date: 
Wednesday, October 29, 2014 - 19:00 - 19:30
Institution: 
UTS
Title: 

“On the value of reframing antibiotic resistance as a disaster risk problem”

Abstract: 

Dr. Maurizio Labbate1,2 & A/Prof. Dale Dominey-Howes3

1School of Medical and Molecular Biosciences, University of Technology, Sydney, Australia.
2The ithree Institute, University of Technology, Sydney, Australia.
3Asia – Pacific Natural Hazards Research Group, School of Geosciences, University of Sydney, Australia.

Abstract:

On the 1st May 2014 the World Health Organization in its first global assessment of antimicrobial resistance reported that antibiotic resistance has now reached alarming proportions and is no longer a future problem but a contemporary reality. This comes off the back of other urgent calls from leading authorities including the Deputy Director of the Center for Disease Control (CDC) who has publicly stated that we have now reached the “end of the antibiotic era” and the UK Chief Medical Officer, Professor Dame Sally Davies who called for antibiotic resistance to be placed on the risk register above the issue of terrorism. Increasingly, the tone of the language used by these organizations and individuals is reminiscent of that used by the disaster and emergency risk management communities to describe commonly occurring disasters such as earthquakes, fires, floods and storms.

Antibiotic resistant infections are rising fast and affect millions of people globally. Antibiotic resistance has become a slow onset disaster that like climate change has struggled to elicit the sort of coordinated international response that is required to deal with the magnitude of the emergency. Anthropogenic modification of the Earth’s climate system provides the foundation for sudden onset natural disasters such as hurricanes, wildfires and storms. Likewise, increasingly widespread antibiotic resistance is laying the foundation for the future occurrence of sudden onset bacterial epidemic and pandemic disasters.

Despite the finest efforts by medical and health policy makers and communities to control the antibiotic resistance problem, the issue has reached a critical tipping point. Given the current state of the antibiotic resistance problem and the likely near future of untreatable bacterial infections, we propose an alternative and novel policy perspective. With this is mind, we propose to make antibiotic a broader issue and reframe it as a disaster risk problem and engage the expertise of emergency managers. Governments and disaster policy makers across the world use the Emergency Risk Management process in the management of and preparation for natural disasters. This process is a systematic method that through engagement with multiple stakeholders identifies, analyses, evaluates and treats risks and takes an iterative approach with well-defined activities that lead to implementation of risk-treatment strategies tailored to a specific community’s risk profile. This policy and practice framework is an excellent mechanism for reaching out to communities and communicating complex messages – an area that needs to be enhanced.

Event Date: 
Wednesday, May 28, 2014 - 18:00 - 18:15
Institution: 
UNSW
Title: 

Regulation of Secondary Metabolites Production in Streptomyces coelicolor

Abstract: 

Streptomyces coelicolor produces a wide array of secondary metabolites that include antibiotics, actinorhodin (Act) and undecylprodigiosin (Red). When analysed for the growth of S. coelicolor on blood containing medium, we found that a functional haemolysin was critical for its growth. Gene knock-out and complementation analysis revealed the expression haemolysin was critical for growth, sporulation and antibiotics production. Total proteome comparison of wild-type and haemolysin deletion mutant indicated a wide range of carbon metabolizing enzymes to be down-regulated. Further analysis of selected targets that could encode phosphomannose isomerase and alpha-mannosidase revealed these sugar processing enzymes to play a critical role on growth, sporulation and antibiotics production in S. coelicolor.

Event Date: 
Wednesday, April 30, 2014 - 18:15 - 18:30
Institution: 
CSIRO
Title: 

Genetic diversity of Group I Clostridium botulinum and Clostridium sporogenes

Abstract: 

Whilst classified as a single bacterial species, Clostridium botulinum comprises a phylogenetically and physiologically diverse collection of organisms. Members of this species are linked together based solely on the production of botulinum neurotoxin (BoNT); amongst most lethal natural toxin produced. Isolates that do not produce BoNT are taxonomically considered a separate species, such as Clostridium sporogenes. Given the species delineation is based solely on an unstable phenetic trait presents increasing challenges in a post-genomic era, particularly with increasing evidence pointing towards the lateral acquisition of BoNT production in many strains. Here, the pan-genome of Group I C. botulinum and C. sporogenes is presented, describing the genetic diversity of these species, highlighting the incongruent taxonomy of these organisms and presenting insights into the acquisition of BoNT within this group.

Event Date: 
Wednesday, May 29, 2013 - 18:15 - 18:30
Institution: 
Macquarie University
Title: 

Dissemination of antibiotic resistance determinants via sewage discharge from Davis Station, Antarctica

Abstract: 

Discharge of untreated or macerated sewage presents a significant risk to Antarctic marine ecosystems by introducing non-native microorganisms that potentially impact microbial communities and threaten health of Antarctic wildlife. Despite these risks, disposal of essentially untreated sewage continues in the Antarctic and sub-Antarctic. As part of an environmental impact assessment of the Davis Station, we investigated carriage of antibiotic resistance determinants in Escherichia coli isolates from marine water and sediments, marine invertebrates (Laturnula and Abatus), birds and mammals within 10 km of the Davis sewage outfall. Class 1 integrons typical of human pathogens and commensals were detected in 12% of E. coli isolates. E. coli carrying these integrons were primarily isolated from the near shore marine water column and the filter feeding mollusc Laturnula. Class 1 integrons were not detected in E. coli isolated from seal (Miroungaleonina, Leptonychotes weddellii) or penguin (Pygoscelis adeliae) feces. However, isolation of E. coli from these vertebrates’ faeces was also low. Consequently, sewage disposal is introducing non-native microorganisms and associated resistance genes into the Antarctic environment. The impact of this “gene pollution” on the diversity and evolution of native Antarctic microbial communities is unknown. 

 

Event Date: 
Wednesday, September 26, 2012 - 18:15
Institution: 
Macquarie University
Title: 

Defining the effluxome of Acinetobacter baumannii

Abstract: 

 
Acinetobacter baumannii is a Gram-negative opportunistic human pathogen known to cause a range of infections in hospitals. Despite their recent emergence, strains of A. baumannii, resistant to essentially all routinely used antibiotics, have been isolated from clinical settings. Bioinformatic analysis identified more than 50 transporter systems with a putative role in drug efflux in the genome of A. baumannii ATCC17978, representing ~2% of all its protein coding ORFs. Based on an assumption that drug transport is often associated with over-expression of a relevant efflux system in the presence of the substrate, high-throughput quantitative reverse-transcriptase PCR (qRT-PCR) has been performed after shock treatments with sub-inhibitory concentrations of antibiotics and differential expression of genes was assessed. This strategy has led to the discovery of novel drug efflux systems and defined physiological functions for previously characterised and novel pumps in drug resistance.
Efflux systems have evolved for millions of years before bacteria such as A. baumannii entered the hospital environment. Presumably, they have initially developed as mechanisms of resistance against naturally occurring substrates. To further characterize the role of efflux systems, cultures of A. baumannii were treated with bioactive natural compounds found in the environment, i.e. soil. These treatments resulted in significant changes in the transcription of efflux pumps indicating their possible role in the defence against compounds found in nature.
Increased expression of efflux systems was also observed when cells of A. baumannii were grown in biofilms compared to planktonic cultures which could suggest that efflux pumps may also play an important role in the functioning of these bacterial communities.

 

Event Date: 
Wednesday, April 27, 2011 - 18:00 - 18:15
Institution: 
Maquarie University
Title: 

Transcriptome led microbial discovery.

Abstract: 

Using a genome wide transcriptomic approach, Karl was able to unravel the role of the Pseudomonas global
activator system (GacA/GacS) in the regulation of an extremely broad range of functions including iron acquisition, oxidative stress response, secondary metabolism and motility. Similar work in Acinetobacter baumannii, a bacterium that is emerging as a major human pathogen due to multiple drug resistance, has revealed the antibiotic efflux to be major mode of resistance and led to the discovery of novel resistance proteins. Karl is a post-
doctoral fellow at Macquarie University working in Prof. Ian Paulsen’s group.

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