CRC50151 Resistance Management

Develop nationally agreed, standard methods for insect sample collection, resistance testing, and data management as a basis for a statistically robust and informative national resistance monitoring program.

Pre-emptive Breeding for Russian Wheat Aphid Resistance

The aims of the project are to 1) identify closely linked molecular markers to resistance genes and validate them in Australian wheat and barley backgrounds, and 2) introgress RWA resistance into Australian wheat and barley backgrounds.

CRC50150 Targeting mechanisms of phosphine resistance in stored grain pests

The objectives of this projects are: 1)To ensure the identification of genomic DNA markers for phosphine resistance in Rhyzopertha dominica and Tribolium castaneum; 2) To determine gene function of identified phosphine resistance genes in Rhyzopertha dominica and Tribolium castaneum; and 3) Predict future problems by characterising international resistances using our genes as a starting point to determine strong resistance can get by determining similarities with Australia.

Australian Herbicide Resistance Initiative (phase 4)

A national focus on strategic and applied research to minimise herbicide resistance in Australian cropping.

Genomics of fumigant resistance in grain pests

Collaborative project with Indian partners to study the genetics of phosphine resistance in Indian strains of grain pests.

CRC50116 - Resistance Monitoring

National Monitoring for resistance to phosphine and grain protectants.

Understanding and management of resistance to Group M, L and I Herbicides

This project will develop better understanding of resistance to glyphosate, paraquat and Group I herbicides to better inform weed management. The project will develop a range of tools for farm advisors to improve their confidence in decision making with respect to reducing the risk of glyphosate, Group I and paraquat resistance. These will include risk assessments, case studies and scenario exploring tools. The project will discuss with commercial providers the potential for new herbicide registrations. The project will establish farm advisor learning groups to work on the application of the research in local areas where resistance is already a major problem and to improve adoption of research outcomes from this and other projects.

Risk assessment and preventive strategies for herbicide resistance in NR (phase III)

The threat and management of glyphosate# resistant weeds are major issues facing northern region growers. At present five weeds are confirmed glyphosate-resistant: barnyard grass, liverseed grass, windmill grass, annual ryegrass and flaxleaf fleabane. This project used 25 experiments to investigate the ecology of the grass weeds, plus new or improved chemical and non-chemical control tactics for them. The refined glyphosate resistance model developed in this project used the experiments' findings to predict the long-term impacts on evolution of resistance and on seed bank numbers of resistant weeds. These data led to revised management and resistance avoidance strategies, which were published in the Reporter newsletter, and via an on-line risk assessment tool. - See more at: http://finalreports.grdc.com.au/UQ00054#sthash.oTkCN4Sk.dpuf

Methicillin Resistance In Staphylococci : Horizontal Transfer of Mobile Genetic Element (SCCmec) Between Staphylococcal Species

Regardless of the existence of antibiotics, infectious diseases are the leading causes of death in the world. Staphylococci cause many infections of varying severity, although they can also exist peacefully in many parts of the human body. Most often Staphylococcus aureus colonises the nose, and that colonisation is considered to be a risk factor for spread of this bacterium. S. aureus is considered to be the most important Staphylococcus species. It poses a challenge to the field of medicine, and one of the most problematic aspects is the drastic increase of the methicillin-resistant S. aureus (MRSA) strains in hospitals and community world-wide, including Finland. In addition, most of the clinical coagulase-negative staphylococcus (CNS) isolates express resistance to methicillin. Methicillin-resistance in S. aureus is caused by the mecA gene that encodes an extra penicillin-binding protein (PBP) 2a. The mecA gene is found in a mobile genomic island called staphylococcal chromosome cassette mec (SCCmec). The SCCmec consists of the mec gene and cassette chromosome recombinase (ccr)gene complexes. The areas of the SCCmec element outside the ccr and mec complex are known as the junkyard J regions. So far, eight types of SCCmec(SCCmec I- SCCmec VIII) and a number of variants have been described. The SCCmec island is an acquired element in S. aureus. Lately, it appears that CNS might be the storage place of the SCCmec that aid the S. aureus by providing it with the resistant elements. The SCCmec is known to exist only in the staphylococci. The aim of the present study was to investigate the horizontal transfer of SCCmec between the S. aureus and CNS. One specific aim was to study whether or not some methicillin-sensitive S. aureus (MSSA) strains are more inclined to receive the SCCmec than others. This was done by comparing the genetic background of clinical MSSA isolates in the health care facilities of the Helsinki and Uusimaa Hospital District in 2001 to the representatives of the epidemic MRSA (EMRSA) genotypes, which have been encountered in Finland during 1992-2004. Majority of the clinical MSSA strains were related to the EMRSA strains. This finding suggests that horizontal transfer of SCCmec from unknown donor(s) to several MSSA background genotypes has occurred in Finland. The molecular characteristics of representative clinical methicillin-resistant S. epidermidis (MRSE) isolates recovered in Finnish hospitals between 1990 and 1998 were also studied, examining their genetic relation to each other and to the internationally recognised MRSE clones as well, so as to ascertain the common traits between the SCCmec elements in MRSE and MRSA. The clinical MRSE strains were genetically related to each other; eleven PFGE types were associated with sequence type ST2 that has been identified world-wide. A single MRSE strain may possess two SCCmec types III and IV, which were recognised among the MRSA strains. Moreover, six months after the onset of an outbreak of MRSA possessing a SCCmec type V in a long-term care facility in Northern Finland (LTCF) in 2003, the SCCmec element of nasally carried methicillin-resistant staphylococci was studied. Among the residents of a LTCF, nasal carriage of MR-CNS was common with extreme diversity of SCCmec types. MRSE was the most prevalent CNS species. Horizontal transfer of SCCmec elements is speculated to be based on the sharing of SCCmec type V between MRSA and MRSE in the same person. Additionally, the SCCmec element of the clinical human S. sciuri isolates was studied. Some of the SCCmec regions were present in S. sciuri and the pls gene was common in it. This finding supports the hypothesis of genetic exchange happening between staphylococcal species. Evaluation of the epidemiology of methicillin-resistant staphylococcal colonisation is necessary in order to understand the apparent emergence of these strains and to develop appropriate control strategies. SCCmec typing is essential for understanding the emergence of MRSA strains from CNS, considering that the MR-CNS may represent the gene pool for the continuous creation of new SCCmec types from which MRSA might originate.

Molecular Details of Serum Resistance of Yersinia enterocolitica

In complement activation, Factor H (FH) and C4b-binding protein (C4bp) are the key regulators that prevent the complement cascade from attacking host tissues. Some bacteria may bind and deposit these regulators on their own surfaces and thus provide themselves with an efficient means to avoid complement activation. In consequence, bacteria resist complement-mediated lysis and opsonin-dependent phagocytosis. This study has demonstrated that Y. enterocolitica, similar to many other pathogens, recruits both FH and C4bp to its surface to ensure protection against the complement-mediated killing. YadA and Ail, the most crucial serum resistance factors of Y.enterocolitica, mediate the binding of FH and C4bp. FH - YadA interaction involves multiple higher structural motifs on the YadA stalk and the short consensus repeats (SCRs) of the entire polypeptide chain of FH. The Ail binding site on FH has been located to SCRs 6 and 7. The binding site for FH on Ail, however, remains undetermined. Both YadA- and Ail-bound regulators display full cofactor activity for FI-mediated cleavage of C3b/C4b. FH/C4bp-binding characteristics do, however, differ between YadA and Ail. In addition, Ail captures the regulators only in the absence of blocking lipopolysaccharide O-antigen and outer core, whereas YadA binds FH/C4bp independent of the presence of other surface factors Independent of mode of binding, however, YadA and Ail provide Y. enterocolitica a means to avoid complement-mediated lysis, enhancing chances for the bacteria to survive in the host during various phases of infection.

Resistance to root-lesion Nematodes for development of molecular markers

This is a sub-project of the Australian Wheat and Barley Molecular Marker Program funded by GRDC and led by Drs Diane Mather and Ken Chalmers of University of Adelaide. In this sub-project we will supply phenotypic data on resistance to two species of root-lesion nematodes (Pratylenchus thornei and P. neglectus) on several populations of wheat doubled haploids. We will also supply existing genotypic data on one doubled haploid population. We will also test one population of doubled haploids (CPI133872/Janz) a second time for resistance to P. thornei and P. neglectus and supply this information to University of Adelaide for the development of molecular markers for use by wheat breeders in selecting for resistance to root-lesion nematodes.

Genetic approaches to resistance to Fusarium and Bipolaris in wheat and barley

This project provided information on the genetics of crown rot (CR) resistance to help breeding work, located new parent lines in wheat and barley, and provided an insight into yield losses that occur in commercial varieties with increasing levels of CR for risk management. Genetic experiments found some highly resistant lines were poor parents, and CR resistance was complex. Best parent lines and many specific crosses were identified for further work. New potential parent lines were identified in wheat and barley, some now used in breeding programs. Yield loss can be severe even with low levels of CR when combined with drought stress. CR can reduce yield even with a wet finish.

CRC20080 Diagnostic technologies for phosphine resistance management

Development of molecular markers for rapid diagnosis of phosphine resistance in insects.

Termite resistance of DMDHEU-treated wood.

Four field trials were conducted with wood modified with dimethyloldihydroxy-ethyleneurea (DMDHEU) in contact with subterranean termites. Trials 1 to 3 were conducted with Coptotermes acinaciformis (Froggatt); 1 and 2 in south-east Queensland, and 3 in northern Queensland, Australia. Trial 4 was conducted in northern Queensland with Mastotermes darwiniensis (Froggatt). Four timber species (Scots pine, beech, Slash pine and Spotted gum) and two levels (1.3 M and 2.3 M) of DMDHEU were used. The tests were validated. DMDHEU successfully prevented damage by C. acinaciformis in south-east Queensland, but not in northern Queensland. It also did not protect the wood against M. darwiniensis. Except for beech in trial 4, DMDHEU led to reduced mass losses caused by termite attack compared to the unmodified feeder stakes. Slash pine (in trials 1 and 3) and Spotted gum (in trial 1) presented low mass losses. Modification of Scots pine was more effective against termite damage than the modification of beech.