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Event Date: 
Wednesday, March 25, 2015 - 19:00 - 19:45
Institution: 
University of Sydney
Title: 

Poxviruses: Man’s Best Friend. (Or How I Learned to Stop Worrying and Love the Virus)

Abstract: 

 

Poxviruses and humans have had a chequered past. Once the scourge known as smallpox routinely devastated human populations, some estimates are as high as 200 million mortalities last century. However the discovery of a tame version of the virus led to Edward Jenner to demonstrate the practise we now know as vaccination, which has gone some way to repairing the reputation of this virus. My research is built on the premise the these viruses still have much to teach us about many aspects of virology and host cell biology. And one of the most novel and exciting applications may be just around the corner.

 

Hi all
 
Please be aware of the following courses being advertised to run at HIE in the next few months. These are a good opportunity to hone your skills in essential and commonly-used science technologies.
 
1)      ‘Data Analysis And Visualization With R' Course - Monday 13th April to Friday 17th April 2015
 
The R statistical computing environment has become a standard for scientific data analysis, visualization and reproducible research. At the HIE, we offer an introductory course to help you climb the steep learning curve. This five-day course is aimed at postgraduate students and staff, and is for newcomers to R.
UWS staff and students can enrol at no charge.
Information at www.uws.edu.au/rcourse
 

Event Date: 
Wednesday, March 25, 2015 - 18:15 - 18:30
Institution: 
University of Florida / UWS
Title: 

Candidatus Liberibacter asiaticus encodes a functional salicylic acid hydroxylase which degrades SA and contributes to the suppression of plant defence

Abstract: 

Salicylate (SA) is a plant hormone and plays important roles in plant defence. SA is synthesized in the chloroplast and transmitted in the phloem. SA hydroxylase is a flavoprotein monooxygenase with the enzyme activity of degradation of SA and is a proximal component of the naphthalene degradation pathway in many bacteria. Candidatus Liberibacter asiaticus, the causal agent of the most devastating citrus disease, is phloem limited and encodes a SA hydroxylase. In this study, we have shown that the SA hydroxylase is functional in degrading SA and its analogs. Ca. L. asiaticus infected plants have reduced PR gene (PR1, PR2, and PR5) expression and SA accumulation in Duncan grapefruit and Valencia sweet orange in response to subsequent inoculation with Xanthomonas citri subsp. citri (Xac) Aw, which is nonpathogenic on both citrus varieties. Ca. L. asiaticus also increased citrus susceptibility to subsequent infection by X. citri. The bacterial populations of XacA and XacAw in grapefruit were significantly higher in Ca. L. asiaticus infected plants compared to healthy control. Our data suggest that Ca. L. asiaticus encodes a functional salicylic acid hydroxylase which degrades SA and contributes to the suppression of plant defence. To counteract this virulence mechanism of Ca. L. asiaticus, foliar spray of SA analogs 2, 6-Dichloroisonicotinic acid (INA) and 2,1,3-Benzothiadiazole (BTH) and SA producing bacterial isolates was conducted to control HLB in large scale field trials. Both INA and BTH in combination with selected bacterial strains slowed down the increase of Ca. L. asiaticus titers in planta and HLB disease severity compared to negative control. SA hydroxylase seems to be an ideal target to develop small molecule inhibitors since no human homolog is present and it is not essential for bacterial growth, hence, the possibility of resistance development is minimized.      Salicylate (SA) is a plant hormone and plays important roles in plant defence. SA is synthesized in the chloroplast and transmitted in the phloem. SA hydroxylase is a flavoprotein monooxygenase with the enzyme activity of degradation of SA and is a proximal component of the naphthalene degradation pathway in many bacteria. Candidatus Liberibacter asiaticus, the causal agent of the most devastating citrus disease, is phloem limited and encodes a SA hydroxylase. In this study, we have shown that the SA hydroxylase is functional in degrading SA and its analogs. Ca. L. asiaticus infected plants have reduced PR gene (PR1, PR2, and PR5) expression and SA accumulation in Duncan grapefruit and Valencia sweet orange in response to subsequent inoculation with Xanthomonas citri subsp. citri (Xac) Aw, which is nonpathogenic on both citrus varieties. Ca. L. asiaticus also increased citrus susceptibility to subsequent infection by X. citri. The bacterial populations of XacA and XacAw in grapefruit were significantly higher in Ca. L. asiaticus infected plants compared to healthy control. Our data suggest that Ca. L. asiaticus encodes a functional salicylic acid hydroxylase which degrades SA and contributes to the suppression of plant defence. To counteract this virulence mechanism of Ca. L. asiaticus, foliar spray of SA analogs 2, 6-Dichloroisonicotinic acid (INA) and 2,1,3-Benzothiadiazole (BTH) and SA producing bacterial isolates was conducted to control HLB in large scale field trials. Both INA and BTH in combination with selected bacterial strains slowed down the increase of Ca. L. asiaticus titers in planta and HLB disease severity compared to negative control. SA hydroxylase seems to be an ideal target to develop small molecule inhibitors since no human homolog is present and it is not essential for bacterial growth, hence, the possibility of resistance development is minimized.      

Event Date: 
Wednesday, February 25, 2015 - 19:30 - 22:30
Institution: 
Australian Museum
Title: 

Two course meal in the skeleton room with live music

Abstract: 

The Cuisine
Flawless & fabulous. We offer creative catered cuisine for all meetings & events, tasty & tantalising to complement your occasion. 

 

Event Date: 
Wednesday, February 25, 2015 - 18:00 - 18:30
Institution: 
San Diego State University
Title: 

Integrating microbial community dynamics into kelp forest ecosystem models

Abstract: 

Metagenomics has enabled a greater understanding of microbial community dynamics than previously realized and now the challenge is to integrate microbial dynamics into ecological models. My lab takes an ‘omics approach mixed with classical microbiology to identify factors affecting microbial communities and how an altered microbial community will affect macro-organism health and ecosystem functioning. The key habitats are coral reefs and kelp forests. Within the kelp forest, we have started with a culturing approach that has identified novel genomes associated with the giant kelp Macrocystis pyrifera. Phenotypic assessments of these bacteria have identified increase in the microbe’s ability to tolerate copper and resist antibiotics with increasing human activities. We have tested the effects of altered microbial abundance and community composition on survival and development of M. pyrifera gametophytes. Decreasing microbial abundance enhanced M. pyrifera recruitment, increasing zoospore settlement and gametophyte development. Gametophytes reared in microbial communities sampled adjacent to the populated city showed lower survival and growth compared to gametophytes in microbial communities from a remote island. Metagenomics revealed a high abundance of phototrophic and oligotrophic microbes from the island, compared with an abundance of eutrophic microbes adjacent to the city. In addition, microbes adjacent to the city lacked genes that produce quorum signaling molecules, negatively influencing kelp spore settlement. Long term analyses of the microbial communities from the kelp forest have been initiated and we are currently investigating the microbes associated with the water column and kelp surface at two distinct depth. First, at 0.5 m depth where the water is warmer, highly oxygenated and receiving large amounts of carbon from photosynthesis and second, at 15 m depth where the water is under seasonal thermocline, colder, lower in oxygen, and can potentially be exposed to high partial pressure of carbon dioxide. Monthly sampling has revealed microbial number is lower at depth and pCO2 is higher. Metagenomic analysis of these samples is under way. Kelp feeds the ecosystem through degradation and we are currently investigating the effects of microbes on kelp degradation and subsequent nutritional value. We have shown altered microbial communities are detrimental to kelp recruitment and are identifying way of adding these data to ecosystem models.

Event Date: 
Wednesday, February 25, 2015 - 17:30 - 18:00
Institution: 
University of Melbourne
Title: 

Genomic epidemiology of antibiotic resistant bacteria

Abstract: 

Microbial populations contribute to human disease in a variety of ways, both as agents of infection and as healthy components of the microbiome. Genomic approaches can offer deep insights into this hidden microbial world, including revealing the composition of microbial communities, tracking the movement of individual organisms, and illuminating evolutionary changes. Here I will present recent work applying genomic epidemiology to investigate the emergence and spread of antibiotic resistance in a range of important pathogens, including typhoid, dysentery and the emerging hospital superbug Klebsiella.

Event Date: 
Wednesday, February 25, 2015 - 17:00 - 17:30
Institution: 
University of Southern Maine
Title: 

Prochlorococcus: the “invisible forest” in the ocean’s Outback.

Abstract: 

The smallest, most abundant phototroph in the world, Prochlorococcus, dominates the base of the food web in the “Outback” of the world’s oceans, the nutrient-depleted ocean gyres. This unicellular, marine cyanobacterium, unknown only 30 years ago, is an oligotrophic specialist with a streamlined genome and reduced cellular requirement for the limited resources available in this environment. Based on physiological and molecular analyses of isolated strains from different oceans and depths, two broad groupings of Prochlorococcus were characterized: high- and low-light adapted “ecotypes”. Within these broad groupings are many subclades, some of which have been shown to dominate under certain temperature and light conditions. Through additional culture-based studies, my lab has been exploring nutrient physiology and other physiological characteristics that may contribute to the ecology and evolution of other Prochlorococcus subgroups. Some subgroups have the capacity to utilize nitrate, which was not the case for the initial isolates of Prochlorococcus, and others differ in their pigmentation. We have also found that Prochlorococcus regulates its uptake velocity and specific affinity for inorganic and organic phosphorus under P stress conditions. Examining the physiology, ecology and genomics of Prochlorococcus isolates and natural populations is providing insights into how these tiny photosynthesizing cells create a stable, yet invisible forest in the deserts of the world’s oceans.

Event Date: 
Wednesday, February 25, 2015 - 16:00 - 17:00
Institution: 
Australian Museum
Title: 

Student poster competition with $500 prize money up for grabs

Abstract: 

NA

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