Complete Mitochondrial Genome for Lucilia cuprina dorsalis (Diptera: Calliphoridae) from the Northern Territory, Australia.

The Australian sheep blowfly, Lucilia cuprina dorsalis, is a major sheep ectoparasite causing subcutaneous myiasis (flystrike), which can lead to reduced livestock productivity and, in severe instances, death of the affected animals. It is also a primary colonizer of carrion, an efficient pollinator, and used in maggot debridement therapy and forensic investigations. In this study, we report the complete mitochondrial (mt) genome of L. c. dorsalis from the Northern Territory (NT), Australia, where sheep are prohibited animals, unlike the rest of Australia. The mt genome is 15,943 bp in length, comprising 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a non-coding control region. The gene order of the current mt genome is consistent with the previously published L. cuprina mt genomes. Nucleotide composition revealed an AT bias, accounting for 77.5% of total mt genome nucleotides. Phylogenetic analyses of 56 species/taxa of dipterans indicated that L. c. dorsalis and L. sericata are the closest among all sibling species of the genus Lucilia, which helps to explain species evolution within the family Luciliinae. This study provides the first complete mt genome sequence for L. c. dorsalis derived from the NT, Australia to facilitate species identification and the examination of the evolutionary history of these blowflies.

Mitochondrial genomic investigation reveals a clear association between species and genotypes of Lucilia and geographic origin in Australia.

BACKGROUND: Lucilia cuprina and L. sericata (family Calliphoridae) are globally significant ectoparasites of sheep. Current literature suggests that only one of these blowfly subspecies, L. cuprina dorsalis, is a primary parasite causing myiasis (flystrike) in sheep in Australia. These species and subspecies are difficult to distinguish using morphological features. Hence, being able to accurately identify blowflies is critical for diagnosis and for understanding their relationships with their hosts and environment. METHODS: In this study, adult blowflies (5 pools of 17 flies; n = 85) were collected from five locations in different states [New South Wales (NSW), Queensland (QLD), Tasmania (TAS), Victoria (VIC) and Western Australia (WA)] of Australia and their mitochondrial (mt) genomes were assembled. RESULTS: Each mt genome assembled was ~ 15 kb in size and encoded 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and a control region. The Lucilia species mt genomes were conserved in structure, and the genes retained the same order and direction. The overall nucleotide composition was heavily biased towards As and Ts-77.7% of the whole genomes. Pairwise nucleotide diversity suggested divergence between Lucilia cuprina cuprina, L. c. dorsalis and L. sericata. Comparative analyses of these mt genomes with published data demonstrated that the blowflies collected from sheep farm in TAS clustered within a clade with L. sericata. The flies collected from an urban location in QLD were more closely related to L. sericata and represented the subspecies L. c. cuprina, whereas the flies collected from sheep farms in NSW, VIC and WA represented the subspecies L. c. dorsalis. CONCLUSIONS: Phylogenetic analyses of the mt genomes representing Lucilia from the five geographic locations in Australia supported the previously demonstrated paraphyly of L. cuprina with respect to L. sericata and revealed that L. c. cuprina is distinct from L. c. dorsalis and that L. c. cuprina is more closely related to L. sericata than L. c. dorsalis. The mt genomes reported here provide an important molecular resource to develop tools for species- and subspecies-level identification of Lucilia from different geographical regions across Australia.

Clinical studies evaluating abametapir lotion, 0.74%, for the treatment of head louse infestation.

BACKGROUND: There is a need for better control of head louse infestations. Abametapir is an inhibitor of metalloproteinases critical for louse survival and egg development. The efficacy of abametapir lotion, 0.74%, was assessed for its ability to clear head louse infestations after a single application. METHODS: Two randomized, double-blind, multicenter, vehicle-controlled studies were conducted in subjects aged 6 months and older to compare the effectiveness of abametapir lotion versus vehicle control for eliminating head louse infestations without nit combing. Abametapir lotion was applied to dry hair for 10 minutes on day 0 and then rinsed with water. The primary endpoint was the proportion of index subjects (youngest household member with ≥ 3 live lice at screening) in the intent-to-treat population who were louse free at all follow-up visits through day 14. Older household members with one or more live lice at screening were designated as nonindex subjects and treated as per the index subject within their household. RESULTS: In the intent-to-treat population (index subjects, N = 216), 81.5% of subjects treated with abametapir lotion were louse free through day 14 after a single treatment, versus 49.1% with vehicle (P < 0.001). For the combined index and nonindex population (N = 704), 85.9% were louse free through day 14 in the abametapir group, versus 61.3% in the vehicle group (P < 0.001). The most frequently reported adverse events were erythema (4.0%), rash (3.2%), and skin burning sensation (2.6%). CONCLUSION: Abametapir lotion, 0.74%, was effective at clearing active head louse infestations through day 14 in subjects aged 6 months and older. All adverse events (including one serious but unrelated to study drug) resolved uneventfully.

The Battle Against Flystrike - Past Research and New Prospects Through Genomics.

Flystrike, or cutaneous myiasis, is caused by blow fly larvae of the genus Lucilia. This disease is a major problem in countries with large sheep populations. In Australia, Lucilia cuprina (Wiedemann, 1830) is the principal fly involved in flystrike. While much research has been conducted on L. cuprina, including physical, chemical, immunological, genetic and biological investigations, the molecular biology of this fly is still poorly understood. The recent sequencing, assembly and annotation of the draft genome and analyses of selected transcriptomes of L. cuprina have given a first global glimpse of its molecular biology and insights into host-fly interactions, insecticide resistance genes and intervention targets. The present article introduces L. cuprina, flystrike and associated issues, details past control efforts and research foci, reviews salient aspects of the L. cuprina genome project and discusses how the new genomic and transcriptomic resources for this fly might accelerate fundamental molecular research of L. cuprina towards developing new methods for the treatment and control of flystrike.

Ovicidal Efficacy of Abametapir Against Eggs of Human Head and Body Lice (Anoplura: Pediculidae).

Studies were undertaken to determine the ovicidal efficacy of 5,5'-dimethyl-2,2'-bipyridyl (abametapir) against eggs of both human head and body lice. Head lice eggs of different ages (0-2, 3-5, and 6-8-d-old eggs) were exposed to varying concentrations of abametapir in isopropanol and concentration-dependent response relationships established based on egg hatch. One hundred percent of all abametapir-treated eggs failed to hatch at the 0.74 and 0.55% concentrations, whereas 100% of 6-8-d-old head louse eggs failed to hatch only at the 0.74% concentration. The LC50 value for abametapir varied, depending on the age of the head lice eggs, from ∼0.10% recorded for 0-2-d-old eggs and increasing to ∼0.15% for 6-8-d-old eggs. Abametapir was also evaluated once formulated into a lotion referred to as Xeglyze (0.74% abametapir) and serial dilutions made. Ovicidal efficacies were determined against head lice eggs 0-8-d-old. Results indicated 100% ovicidal activity at the 0.74, 0.55, 0.37, and 0.18% concentrations. Additional studies undertaken using body lice eggs also demonstrated that abametapir was 100% ovicidal against eggs of all ages when evaluated at a concentration of 0.37 and 0.55%. Given that ovicidal activity is a critical component of any effective treatment regime for louse control, the data presented in this study clearly demonstrate the ability of abametapir to inhibit hatching of both head and body louse eggs as assessed in vitro.

A blow to the fly - Lucilia cuprina draft genome and transcriptome to support advances in biology and biotechnology.

The blow fly, Lucilia cuprina (Wiedemann, 1830) is a parasitic insect of major global economic importance. Maggots of this fly parasitize the skin of animal hosts, feed on excretions and tissues, and cause severe disease (flystrike or myiasis). Although there has been considerable research on L. cuprina over the years, little is understood about the molecular biology, biochemistry and genetics of this parasitic fly, as well as its relationship with its hosts and the disease that it causes. This situation might change with the recent report of the draft genome and transcriptome of this blow fly, which has given new and global insights into its biology, interactions with the host animal and aspects of insecticide resistance at the molecular level. This genomic resource will likely enable many fundamental and applied research areas in the future. The present article gives a background on L. cuprina and myiasis, a brief account of past and current treatment, prevention and control approaches, and provides a perspective on the impact that the L. cuprina genome should have on future research of this and related parasitic flies, and the design of new and improved interventions for myiasis.

The ovicidal, larvacidal and adulticidal properties of 5,5'-dimethyl-2,2'-bipyridyl against Drosophila melanogaster.

Insecticide resistance has limited the number of available chemical options for insect pest control. Hence there is a need for new chemistries with novel modes of action. Here we investigate the mode of action for an insecticide that has not yet been released for commercial use. The ovicidal, larvacidal and adulticidal effects of 5,5'-dimethyl -2, 2'-dipyridyl (termed Ha44), which is being developed as a treatment for head lice, were evaluated in the Drosophila melanogaster model system. Ha44 demonstrated significant activity against embryos and was capable of arresting development at a number of stages of embryogenesis. The effects of Ha44 on embryos was shown to be reversible following the addition of the metal ions Fe(II) and Fe(III), Cu and Zn. When larvae were exposed to Ha44, lethality was recorded at similar concentrations to those observed for embryos. Using an eYFP reporter system it was shown that Ha44 was able to reduce the levels of both copper and zinc in the digestive tract, confirming the binding of Ha44 to these metals in vivo. Ha44 has further been shown to inhibit a zinc containing metalloproteinase in vitro. Exposure of adult flies to Ha44 resulted in lethality, but at higher concentrations than those observed for embryos and larvae. The median lethal dose in adult flies was shown to be associated with the type of exposure, with an LD-50 of 1.57 mM being recorded following the direct contact of flies with Ha44, while an LD-50 of 12.29 mM was recorded following the ingestion of the compound. The capacity of Ha44 to act on all stages of the life-cycle and potentially via a range of targets suggests that target site resistance is unlikely to evolve.

Biomedical applications of sheep models: from asthma to vaccines.

Although rodent models are very popular for scientific studies, it is becoming more evident that large animal models can provide unique opportunities for biomedical research. Sheep are docile in nature and large in size, which facilitates surgical manipulation, and their physiology is similar to humans. As a result, for decades they have been chosen for several models and continue to be used to study an ever-increasing array of applications. Despite this, their full potential has not been exploited. Here, we review the use of sheep as an animal model for human vaccine development, asthma pathogenesis and treatment, the study of neonatal development, and the optimization of drug delivery and surgical techniques.