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Malaria, a disease caused by the Plasmodium parasite, accounts for more than 450 000 deaths annually. The devastating impact of this disease is compounded by the emergence or risk of widespread resistance to current antimalarial drugs, underscoring the need to develop new therapies. Australian scientists are at the forefront of fundamental, clinical and surveillance research, and have made significant contributions to advancing the field of malaria research. A significant component of this research has been directed toward the development of new antimalarial therapies. This perspective summarises the recent endeavours by Australian researchers in chemistry and drug discovery sciences in the identification and development of new antimalarial therapies in the global challenge to treat and eliminate malaria. Malaria is a devasting disease that causes significant morbidity and mortality worldwide. New therapies are urgently needed, because of the emergent resistance against current frontline therapies. This perspective highlights the contributions of Australian chemists and drug discovery experts to the field of antimalarial development. [ABSTRACT FROM AUTHOR]

The three members of the lecanicephalidean tapeworm family Eniochobothriidae are unusual among tapeworms in that they lack a vagina and possess a series of expanded proglottids forming a trough at the anterior end of their body. They exclusively parasitise cownose rays of the genus Rhinoptera (Myliobatiformes: Rhinopteridae). New collections from six of the nine known species of cownose rays from the waters off Australia, Mexico, Mozambique, Senegal, Taiwan and the United States (off Mississippi, Louisiana and South Carolina) yielded eight new species and a new genus of eniochobothriids. Here we erect Amiculucestus , gen. nov. and describe six of the eight new species – four in the new genus and two in Eniochobothrium – expanding the number of genera in the family to two and the number of described species in the family to nine. Morphological work was based on light and scanning electron microscopy. The tree resulting from a maximum likelihood analysis of sequence data for the D1–D3 region of the 28S rDNA gene for 11 species of eniochobothriids supports the reciprocal monophyly of both genera. The mode of attachment to the mucosal surface of the spiral intestine of the host was investigated using histological sections of worms in situ. These cestodes appear to use the anterior trough-like portion of their body, which consists of an unusual series of barren proglottids, rather than their scolex, to attach to the mucosal surface. Based on our new collections, we estimate that the total number of eniochobothriids across the globe does not exceed 27 species. ZooBank LSID: urn:lsid:zoobank.org:pub:0740EC72‐AC3F‐43AA‐BD41‐B9820BA9D0CE Eniochobothriids, which parasitise soley cownose rays, are particularly intriguing because of their mode of attachment and lack of a vagina. New collections from around the globe yielded substantial, previously unrecognised diversity. Supported by molecular sequence data, a new genus is erected and six new species are described. The mode of attachment for the family is described. Given the limited spectrum of hosts for members of the family, its diversity is predicted not to exceed 27 species globally. [ABSTRACT FROM AUTHOR]

Context. Parasite control is an essential part of a broader equine health-management strategy and is often completely administered by the horse owner, with little or no supporting evidence on which to base decisions. Practical and sound advice relies on knowledge of the resident parasite species, the anthelmintic resistance status of important species, and the strategies currently being utilised by owners and managers of horses. Much of this farm-level information is lacking in the Australian literature. Aims. The present study aimed to gather both farm- and horse-level prevalence data for four important equine helminth species and to gather information on the current worm-management practices conducted on Australian horse farms. Methods. We conducted a coprological survey of cyathostomins, Strongylus vulgaris, Parascaris spp. and equine tapeworm on 102 horse properties, using a combination of classical and molecular parasitological methods, including a tapeworm polymerase chain reaction developed as part of the study. A questionnaire canvasing horse owners on internal parasite-control practices was also distributed. Key results. Cyathostomin were present on all farms surveyed and S. vulgaris, despite being considered rare, was present on 7.8% (95% CI: 3.9-15.0) of farms. The prevalence of Parascaris spp. and equine tapeworm was 33.3% (95% CI: 19.6-50.6) and 3.9% (95% CI: 1.5-10.1) respectively. Questionnaire responses showed that the majority (85.0%) of horse owners administer anthelmintics at regular intervals of 12 weeks or less, and only 2.6% utilise faecal egg counts to inform treatment decisions. Conclusions. Prevalence data confirmed the endemic nature of cyathostomin and P. equorum infections, as well as low levels of tapeworm and S. vulgaris infections on Australian horse farms. Worm-management practices were reminiscent of traditional interval-style treatment regimens that rely heavily on macrocyclic lactone anthelmintics. Implications. These results suggest a need for more strategic approaches to internal-parasite control in horses to slow the development of anthelmintic resistance. Such programs need to consider the risk of re-establishment of the pathogenic S. vulgaris in significant numbers. [ABSTRACT FROM AUTHOR]

Globally horn flies (Haematobia irritans) are one of the most economically damaging parasites of beef cattle. These obligate blood-feeding external parasites take blood meals from cattle leading to blood loss, annoyance avoidance behaviours, and reductions in animal performance. Development of chemical resistance by horn flies suggests that novel management strategies are needed. More in-depth understanding of parasitism relative to hide colour and temperature, especially in a changing climate, may enhance animal production. In peak parasitism periods of 2016 and 2017, we measured horn fly loads on commingled black Angus and white Charolais cows in a cold high-elevation rangeland in Wyoming, USA. We tested how breed, year, and interactions explained horn fly parasitism and economic thresholds. In 2016 we also measured ambient and external cow temperatures to further elucidate thermal ecology mechanisms explaining horn fly hide colour preferences. Mean annual horn fly infestations were always four times greater or more on black cows than white cattle both years, but not all cattle reached economic thresholds all years and the breed by year interaction was not significant. Difference in horn fly preference for black cattle over white cattle in our cold high-elevation environment may be explained by greater absolute and relative external surface temperatures of black hided cows. Host colour and thermal preferences of horn flies could be incorporated into integrated pest management strategies that only treat darker hided cattle and producers in cold high-elevation environments conduct real-time monitoring to determine if treatments are even needed on a year-by-year basis. Horn flies, an external parasite of cattle, are not well understood in high-elevation rangelands. We measured horn flies on black Angus cows and white Charolais cows in 2016 and 2017. Annual fly infestations were four times greater or more on black cows both years. Not all cattle reached economic thresholds all years. Cow colour fly preference in our environment may be explained by external temperatures of black cows. Manipulating host colour and thermal preferences of horn flies could enhance beef production. [ABSTRACT FROM AUTHOR]

Wildlife parasitology is a highly diverse area of research encompassing many fields including taxonomy, ecology, pathology and epidemiology, and with participants from extremely disparate scientific fields. In addition, the organisms studied are highly dissimilar, ranging from platyhelminths, nematodes and acanthocephalans to insects, arachnids, crustaceans and protists. This review of the parasites of wildlife in Australia highlights the advances made to date, focussing on the work, interests and major findings of researchers over the years and identifies current significant gaps that exist in our understanding. The review is divided into three sections covering protist, helminth and arthropod parasites. The challenge to document the diversity of parasites in Australia continues at a traditional level but the advent of molecular methods has heightened the significance of this issue. Modern methods are providing an avenue for major advances in documenting and restructuring the phylogeny of protistan parasites in particular, while facilitating the recognition of species complexes in helminth taxa previously defined by traditional morphological methods. The life cycles, ecology and general biology of most parasites of wildlife in Australia are extremely poorly understood. While the phylogenetic origins of the Australian vertebrate fauna are complex, so too are the likely origins of their parasites, which do not necessarily mirror those of their hosts. This aspect of parasite evolution is a continuing area for research in the case of helminths, but remains to be addressed for many other parasitic groups. Wildlife parasitology is a highly diverse area of research encompassing disparate scientific disciplines and practitioners investigating highly dissimilar organisms. This review highlights advances made to date and identifies current significant gaps which exist in our understanding. Modern molecular methods are providing major advances in documenting and re-structuring the phylogeny of parasitic groups and facilitating recognition of species complexes in taxa previously defined by traditional morphological methods. Photo courtesy of Ian Beveridge, Australian Society for Parasitology and Lee Skerratt. [ABSTRACT FROM AUTHOR]

Parasites form an integral part of overall biodiversity although they are often overlooked in conservation management, where emphasis is primarily directed towards the host. Parasites are often highly specialised to particular hosts, and thus may be just as threatened as the host they inhabit. For many of Australia's wildlife species, little is known about their associated parasite communities. To begin to address this knowledge gap, we documented the parasite fauna described in the genetically diverse marsupial genus Petrogale, which contains seven species of conservation concern. The literature evaluation showed parasites of Petrogale to be highly diverse, with 17 species of protozoa, 8 species of cestodes, 102 species of nematodes and 30 species of ectoparasites identified in 16 of 17 Petrogale host species. A comparison of the parasite communities amongst Petrogale host species indicated a highly significant correlation between the parasite community similarity, and the phylogeny (P = 0.008) and biogeography (P = 0.0001) of their Petrogale hosts, suggesting high host specificity within their associated parasite assemblages. Five Petrogale species have established species recovery programs and their parasite communities should also be considered threatened, and management of parasite diversity required as part of these conservation programs. [ABSTRACT FROM AUTHOR]

The Cicerone Project conducted a grazed farmlet experiment on the Northern Tablelands of New South Wales, Australia, from July 2000 to December 2006, to address questions raised by local graziers concerning how they might improve the profitability and sustainability of their grazing enterprises. This unreplicated experiment examined three management systems at a whole-farmlet scale. The control farmlet (farmlet B) represented typical management for the region, with flexible rotational grazing and moderate inputs. A second farmlet (farmlet A) also used flexible rotational grazing but had a higher level of pasture renovation and soil fertility, while the third farmlet (farmlet C) had the same moderate inputs as farmlet B but employed intensive rotational grazing. The present paper provides an integrated overview of the results collated from component papers and discusses the inferences that can be drawn from what was a complex, agroecosystem experiment. The measurements recorded both early and late in the experiment were tabulated for each of the farmlets and compared with each other as relative proportions, allowing visual presentation on a common, indexed scale. Because of equivalent starting conditions, there was little difference between farmlets early in the experimental period (2000-01) across a wide array of measured parameters, including herbage mass, potential pasture growth rate, liveweight, wool production per head, stocking rate, gross margin and equity. Although the experiment experienced drier-than-average conditions, marked differences emerged among farmlets over time, due to the effects of treatments. During the latter half of the experimental period (2003-06), farmlet A showed numerous positive and a few negative consequences of the higher rate of pasture renovation and increased soil fertility compared with the other two farmlets. While intensive rotational grazing resulted in superior control of gastrointestinal nematodes and slightly finer wool, this system had few effects on pastures and no positive effects on sheep liveweights, wool production or stocking rate. Whereas farmlet A showed higher gross margins, it had a negative and lower short-term cash position than did farmlets B and C, due largely to the artificially high rate of pasture renovation undertaken on this farmlet during the experiment. Although farmlet B had the highest cash position at the end of the experiment, this came at a cost of the declining quality of its pastures. Modelling of the farmlet systems allowed the results to be considered over the longer timeframes needed to assess sustainability. Thus, returns on investment were compared over realistic amortisation periods and produced outcomes based on long-term climatic expectations which were compared with those that arose under the drier-than-average conditions experienced during the experimental period. The main factors responsible for lifting the productivity of farmlet A were the sowing of temperate species and increased soil fertility, which enhanced the amount of legume and increased pasture quality and potential pasture growth. The factor that affected farmlet C most was the low proportion of the farmlet grazed at any one time, with high stock density imposed during grazing, which decreased feed intake quality. The paper concludes that more profitable and sustainable outcomes are most likely to arise from grazing enterprises that are proactively managed towards optimal outcomes by maintaining sufficient desirable perennial grasses with adequate legume content, enhancing soil fertility and employing flexible rotational grazing. Enhancing our understanding of grazed agroecosystems is a great challenge because so many factors interact in complex ways. An integrated overview of a whole-farmlet study is presented which demonstrates how the performance of different components of the farmlets changed over time. More profitable and sustainable systems are those which focus on flexible grazing management and improving pastures and soil fertility. [ABSTRACT FROM AUTHOR]