Pyrantel resistance in canine hookworms in Queensland, Australia.

Hookworms are the most common intestinal nematode parasites of dogs in Australia. The control of these parasites relies mostly on regular deworming with anthelmintics, with pyrantel-based dewormers being a relatively low cost and readily-available option for dog owners. Pyrantel resistance in canine hookworms in Australia was first reported in 2007, however pyrantel-based dewormers are still used against hookworm infection in dogs across Australia. The present study was conducted to evaluate the efficacy of pyrantel against hookworms infecting dogs housed in a shelter facility in Southeast Queensland which receives rescued or surrendered animals from greyhound rescue centres and dog shelters across this region. A total of 10 dogs were examined using the faecal egg count reduction test (FECRT). There was no reduction in FEC in any of the dogs following pyrantel treatment, with drug efficacies ranging from -0.9% to -283.3%. Given that these dogs originated from various sites across Southeast Queensland, the present study suggests that pyrantel resistance is widespread in this region, and hence this anthelmintic may not be a useful option for treatment of hookworm infections in dogs.

Transmission-Blocking Vaccines against Schistosomiasis Japonica.

Control of schistosomiasis japonica, endemic in Asia, including the Philippines, China, and Indonesia, is extremely challenging. Schistosoma japonicum is a highly pathogenic helminth parasite, with disease arising predominantly from an immune reaction to entrapped parasite eggs in tissues. Females of this species can generate 1000-2200 eggs per day, which is about 3- to 15-fold greater than the egg output of other schistosome species. Bovines (water buffalo and cattle) are the predominant definitive hosts and are estimated to generate up to 90% of parasite eggs released into the environment in rural endemic areas where these hosts and humans are present. Here, we highlight the necessity of developing veterinary transmission-blocking vaccines for bovines to better control the disease and review potential vaccine candidates. We also point out that the approach to producing efficacious transmission-blocking animal-based vaccines before moving on to human vaccines is crucial. This will result in effective and feasible public health outcomes in agreement with the One Health concept to achieve optimum health for people, animals, and the environment. Indeed, incorporating a veterinary-based transmission vaccine, coupled with interventions such as human mass drug administration, improved sanitation and hygiene, health education, and snail control, would be invaluable to eliminating zoonotic schistosomiasis.

Current and upcoming point-of-care diagnostics for schistosomiasis.

Point-of-care (POC) diagnostics are simple and effective portable tools that can be used for fast mapping of helminthic diseases and monitoring control programs. Most POC tests (POCTs) available for schistosomiasis diagnosis are lateral flow immunoassays (LFIAs). The emergence of simple and rapid DNA isolation methods, along with isothermal nucleic acid amplification strategies - for example, loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA) - and recent clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostic methods facilitate the development of molecular-based POC diagnostics for schistosomiasis. Furthermore, smartphone-based techniques increase real-time connectivity and readout accuracy of POCTs. This review discusses the recent advances in immunological-, molecular-based POCTs and mobile phone microscopes for the diagnosis/screening of schistosomiasis.

Comparative assessment of the SjSAP4-incorporated gold immunochromatographic assay for the diagnosis of human schistosomiasis japonica.

Background: Schistosomiasis, a disease caused by parasites of the genus Schistosoma, remains a global public health threat. This study aimed to validate the diagnostic performance of a recently developed gold immunochromatographic assay (GICA) for the detection of S. japonicum infection in a rural endemic area of the Philippines. Methods: Human clinical samples were collected from 412 subjects living in Laoang and Palapag municipalities, Northern Samar, the Philippines. The presence of Schistosoma-specific antibodies in serum samples was tested with the SjSAP4-incorporated GICA strips and the results were converted to fully quantitative data by introducing an R value. The performance of the established GICA was further compared with other diagnostic tools, including the Kato-Katz (KK) technique, point-of-care circulating cathodic antigen (POC-CCA), droplet digital (dd) PCR, and enzyme-linked immunosorbent assays (ELISAs). Results: The developed GICA strip was able to detect KK positive individuals with a sensitivity of 83.3% and absolute specificity. When calibrated with the highly sensitive faecal ddPCR assay, the immunochromatographic assay displayed an accuracy of 60.7%. Globally, the GICA assay showed a high concordance with the SjSAP4-ELISA assay. The schistosomiasis positivity rate determined by the GICA test was similar to those obtained with the SjSAP4-ELISA assay and the ddPCR assay performed on serum samples (SR_ddPCR), and was 2.3 times higher than obtained with the KK method. Conclusion: The study further confirms that the developed GICA is a valuable diagnostic tool for detecting light S. japonicum infections and implies that this point-of-care assay is a viable solution for surveying endemic areas of low-intensity schistosomiasis and identifying high-priority endemic areas for targeted interventions.

Optimisation of the DNA dipstick as a rapid extraction method for Schistosoma japonicum in infected mice samples and spiked human clinical samples.

BACKGROUND: Schistosomiasis remains a public health issue and the need for accurate and affordable diagnostics is crucial in the elimination of the disease. While molecular diagnostics are highly effective, they are expensive, with the main costs been associated with DNA extraction. The DNA dipstick is a rapid, affordable and simple purification method that allows DNA to be extracted from diagnostic samples within 30 s. We aimed to optimise the DNA dipstick method for samples from mice and egg-spiked human samples. METHODS: Urine, blood and faeces were collected from mice exposed to Schistosoma japonicum infection at weekly intervals from Day 0 to Day 42. Urine and faecal samples were also collected from volunteer, uninfected humans and spiked with S. japonicum eggs. All samples were subject to several optimisation procedures and DNA extracted with the DNA dipstick. Amplification of the target DNA was carried out using LAMP and visualised using agarose gel electrophoresis and flocculation. RESULTS: The DNA dipstick successfully identified S. japonicum from infected mice and human clinical samples spiked with cracked eggs or genomic DNA from S. japonicum. Amplification was observed from week 4 post infection in infected mice. For human samples, amplification was observed in sieved faecal samples, filtered urine samples heated at 95 °C for 30 min, and sera samples heated at 95 °C for 30 min. CONCLUSIONS: The DNA dipstick combined with LAMP has huge potential in providing cost-effective, simple and accurate detection of schistosomiasis infection in endemic regions. This will allow for rapid treatment, tracking outbreaks-such as occur after typhoons, leading to better health outcomes and contributing to control and eventual elimination of schistosomiasis.

Development of CRISPR/Cas13a-based assays for the diagnosis of Schistosomiasis.

BACKGROUND: Schistosomiasis is a disease that significantly impacts human health in the developing world. Effective diagnostics are urgently needed for improved control of this disease. CRISPR-based technology has rapidly accelerated the development of a revolutionary and powerful diagnostics platform, resulting in the advancement of a class of ultrasensitive, specific, cost-effective and portable diagnostics, typified by applications in COVID-19/cancer diagnosis. METHODS: We developed CRISPR-based diagnostic platform SHERLOCK (Specific High-sensitivity Enzymatic Reporter unLOCKing) for the detection of Schistosoma japonicum and S. mansoni by combining recombinase polymerase amplification (RPA) with CRISPR-Cas13a detection, measured via fluorescent or colorimetric readouts. We evaluated SHERLOCK assays by using 150 faecal/serum samples collected from Schistosoma-infected ARC Swiss mice (female), and 189 human faecal/serum samples obtained from a S. japonicum-endemic area in the Philippines and a S. mansoni-endemic area in Uganda. FINDINGS: The S. japonicum SHERLOCK assay achieved 93-100% concordance with gold-standard qPCR detection across all the samples. The S. mansoni SHERLOCK assay demonstrated higher sensitivity than qPCR and was able to detect infection in mouse serum as early as 3 weeks post-infection. In human samples, S. mansoni SHERLOCK had 100% sensitivity when compared to qPCR of faecal and serum samples. INTERPRETATION: These schistosomiasis diagnostic assays demonstrate the potential of SHERLOCK/CRISPR-based diagnostics to provide highly accurate and field-friendly point-of-care tests that could provide the next generation of diagnostic and surveillance tools for parasitic neglected tropical diseases. FUNDING: Australian Infectious Diseases Research Centre seed grant (2022) and National Health and Medical Research Council (NHMRC) of Australia (APP1194462, APP2008433).

The mRNA Vaccine Technology Era and the Future Control of Parasitic Infections.

Despite intensive long-term efforts, with very few exceptions, the development of effective vaccines against parasitic infections has presented considerable challenges, given the complexity of parasite life cycles, the interplay between parasites and their hosts, and their capacity to escape the host immune system and to regulate host immune responses. For many parasitic diseases, conventional vaccine platforms have generally proven ill suited, considering the complex manufacturing processes involved and the costs they incur, the inability to posttranslationally modify cloned target antigens, and the absence of long-lasting protective immunity induced by these antigens. An effective antiparasite vaccine platform is required to assess the effectiveness of novel vaccine candidates at high throughput. By exploiting the approach that has recently been used successfully to produce highly protective COVID mRNA vaccines, we anticipate a new wave of research to advance the use of mRNA vaccines to prevent parasitic infections in the near future. This article considers the characteristics that are required to develop a potent antiparasite vaccine and provides a conceptual foundation to promote the development of parasite mRNA-based vaccines. We review the recent advances and challenges encountered in developing antiparasite vaccines and evaluate the potential of developing mRNA vaccines against parasites, including those causing diseases such as malaria and schistosomiasis, against which vaccines are currently suboptimal or not yet available.

Lentiviral Transduction-based CRISPR/Cas9 Editing of Schistosoma mansoni Acetylcholinesterase.

Background: Recent studies on CRISPR/Cas9-mediated gene editing in Schistosoma mansoni have shed new light on the study and control of this parasitic helminth. However, the gene editing efficiency in this parasite is modest. Methods: To improve the efficiency of CRISPR/Cas9 genome editing in schistosomes, we used lentivirus, which has been effectively used for gene editing in mammalian cells, to deliver plasmid DNA encoding Cas9 nuclease, a sgRNA targeting acetylcholinesterase (SmAChE) and a mCherry fluorescence marker into schistosomes. Results: MCherry fluorescence was observed in transduced eggs, schistosomula, and adult worms, indicating that the CRISPR components had been delivered into these parasite stages by lentivirus. In addition, clearly changed phenotypes were observed in SmAChE-edited parasites, including decreased SmAChE activity, reduced hatching ability of edited eggs, and altered behavior of miracidia hatched from edited eggs. Next-generation sequencing analysis demonstrated that the lentiviral transduction-based CRISPR/Cas9 gene modifications in SmAChE-edited schistosomes were homology-directed repair predominant but with much lower efficiency than that obtained using electroporation (data previously published by our laboratory) for the delivery of CRISPR components. Conclusion: Taken together, electroporation is more efficient than lentiviral transduction in the delivery of CRISPR/Cas9 into schistosomes for programmed genome editing. The exploration of tactics for enhancing CRISPR/Cas9 gene editing provides the basis for the future improvement of programmed genome editing in S. mansoni.

Schistosoma mansoni Fibroblast Growth Factor Receptor A Orchestrates Multiple Functions in Schistosome Biology and in the Host-Parasite Interplay.

Stem cells play significant roles in driving the complex life cycle of Schistosoma mansoni. Fibroblast growth factor (FGF) receptor A (SmFGFRA) is essential for maintaining the integrity of schistosome stem cells. Using immunolocalization, we demonstrated that SmFGFRA was distributed abundantly in germinal/stem cells of different S. mansoni life stages including eggs, miracidia, cercariae, schistosomula and adult worms. Indeed, SmFGFRA was also localized amply in embryonic cells and in the perinuclear region of immature eggs; von Lichtenberg's layer and the neural mass of mature eggs; the ciliated surface and neural mass of miracidia; the tegument cytosol of cercariae, schistosomula and adult worms; and was present in abundance in the testis and vitellaria of adult worms of S. mansoni. The distribution pattern of SmFGFRA illustrates the importance of this molecule in maintaining stem cells, development of the nervous and reproductive system of schistosomes, and in the host-parasite interplay. We showed SmFGFRA can bind human FGFs, activating the mitogen activated protein kinase (MAPK) pathway of adult worms in vitro. Inhibition of FGF signaling by the specific tyrosine kinase inhibitor BIBF 1120 significantly reduced egg hatching ability and affected the behavior of miracidia hatched from the treated eggs, emphasizing the importance of FGF signaling in driving the life cycle of S. mansoni. Our findings provide increased understanding of the complex schistosome life cycle and host-parasite interactions, indicating components of the FGF signaling pathway may represent promising targets for developing new interventions against schistosomiasis.

Description of the female, nymph and larva and mitochondrial genome, and redescription of the male of Ixodes barkeri Barker, 2019 (Acari: Ixodidae), from the short-beaked echidna, Tachyglossus aculeatus, with a consideration of the most suitable subgenus for this tick.

BACKGROUND: Ixodes barkeri, a tick with a distinctive ventrolateral horn-like projection on palpal segment 1, was described in 2019 from two male ticks from the Wet Tropics of Far North Queensland, Australia. However, females lie at the core of the taxonomy and subgenus classification of Ixodes; hence, we sought specimens of female ticks, successfully recovering females, plus nymphs and larvae. Mitochondrial genomes are also desirable additions to the descriptions of species of ticks particularly regarding subgenus systematics. So, we sequenced the mt genomes of I. barkeri Barker, 2019, and the possible relatives of I. barkeri that were available to us (I. australiensis Neumann, 1904, I. fecialis Warburton & Nuttall, 1909, and I. woyliei Ash et al. 2017) with a view to discovering which if any of the subgenera of Ixodes would be most suitable for I. barkeri Barker, 2019. RESULTS: The female, nymph, larva and mitochondrial genome of Ixodes barkeri Barker, 2019, are described for the first time and the male of I. barkeri is redescribed in greater detail than previously. So far, I. barkeri is known only from a monotreme, the short-beaked echidna, Tachyglossus aculeatus (Shaw, 1792), from the highland rainforests of the Wet Tropics of Far North Queensland, Australia. CONCLUSIONS: Our phylogeny from entire mitochondrial genomes indicated that I. barkeri and indeed I. woyliei Ash et al., 2017, another tick that was described recently, are best placed in the subgenus Endopalpiger Schulze, 1935.

Rediscovery of Ixodes confusus in Australia with the first description of the male from Australia, a redescription of the female and the mitochondrial (mt) genomes of five species of Ixodes.

We: (i) report the rediscovery of Ixodes (Sternalixodes) confusus Roberts, 1960 in Australia; (ii) redescribe the male and female of I. confusus; (iii) describe the mitochondrial (mt) genome of I. confusus from five ticks from four localities in Far North Queensland; and (iv) present the first substantial phylogeny of the subgenera of the Ixodes. The mt genomes of I. confusus, I. cornuatus, I. hirsti, I. myrmecobii and I. trichosuri are presented here for the first time. In our phylogeny from entire mt genomes (ca. 15 kb), the subgenus Endopalpiger was the sister-group to subgenera Sternalixodes plus Ceratixodes plus Exopalpiger whereas Exopalpiger was the sister to Sternalixodes plus Ceratixodes. [i.e. ((Endopalpiger) (Sternalixodes, Ceratixodes and Exopalpiger))]. Finally, we show that Ixodes anatis, the kiwi tick, may be closely related to the ticks of marsupials of Australia and Papua New Guinea.

Adult schistosomes have an epithelial bacterial population distinct from the surrounding mammalian host blood.

BACKGROUND: Schistosomiasis is a neglected tropical parasitic and chronic disease affecting hundreds of millions of people. Adult schistosomes reside in the blood stream of the definitive mammalian host. These helminth parasites possess two epithelial surfaces, the tegument and the gastrodermis, both of which interact with the host during immune evasion and in nutrient uptake. METHODS: Female ARC Swiss mice (4-6 weeks old) were infected percutaneously with Schistosoma japonicum cercariae freshly shed from Oncomelania hupensis quadrasi snails (Philippines strain). Fluorescent in situ hybridisation (FISH) was performed by using fresh adult S. japonicum perfused from those infected mice. Adult S. japonicum worms were processed to isolate the tegument from the carcass containing the gastrodermis; blood and bile were collected individually from infected and uninfected mice. Total DNA extracted from all those samples were used for microbiome profiling. RESULTS: FISH and microbiome profiling showed the presence of bacterial populations on two epithelial surfaces of adult worms, suggesting they were distinct not only from the host blood but also from each other. Whereas microbial diversity was reduced overall in the parasite epithelial tissues when compared with that of host blood, specific bacterial taxa, including Anoxybacillus and Escherichia, were elevated on the tegument. Minimal differences were evident in the microbiome of host blood during an active infection, compared with that of control uninfected blood. However, sampling of bile from infected animals identified some differences compared with controls, including elevated levels of Limnohabitans, Clostridium and Curvibacter. CONCLUSIONS: Using FISH and microbial profiling, we were able to demonstrate, for the first time, that bacteria are presented on the epithelial surfaces of adult schistosomes. These schistosome surface-associated bacteria, which are distinct from the host blood microenvironment, should be considered as a new and important component of the host-schistosome interaction. The importance of individual bacterial species in relation to schistosome parasitism needs further elucidation.

CRISPR interference for sequence-specific regulation of fibroblast growth factor receptor A in Schistosoma mansoni.

Employing the flatworm parasite Schistosoma mansoni as a model, we report the first application of CRISPR interference (CRISPRi) in parasitic helminths for loss-of-function studies targeting the SmfgfrA gene which encodes the stem cell marker, fibroblast growth factor receptor A (FGFRA). SmFGFRA is essential for maintaining schistosome stem cells and critical in the schistosome-host interplay. The SmfgfrA gene was targeted in S. mansoni adult worms, eggs and schistosomula using a catalytically dead Cas9 (dCas9) fused to a transcriptional repressor KRAB. We showed that SmfgfrA repression resulted in considerable phenotypic differences in the modulated parasites compared with controls, including reduced levels of SmfgfrA transcription and decreased protein expression of SmFGFRA, a decline in EdU (thymidine analog 5-ethynyl-2'-deoxyuridine, which specifically stains schistosome stem cells) signal, and an increase in cell apoptosis. Notably, reduced SmfgfrA transcription was evident in miracidia hatched from SmfgfrA-repressed eggs, and resulted in a significant change in miracidial behavior, indicative of a durable repression effect caused by CRISPRi. Intravenous injection of mice with SmfgfrA-repressed eggs resulted in granulomas that were markedly reduced in size and a decline in the level of serum IgE, emphasizing the importance of SmFGFRA in regulating the host immune response induced during schistosome infection. Our findings show the feasibility of applying CRISPRi for effective, targeted transcriptional repression in schistosomes, and provide the basis for employing CRISPRi to selectively perturb gene expression in parasitic helminths on a genome-wide scale.

Fifty years of the schistosome tegument: discoveries, controversies, and outstanding questions.

The unique multilaminate appearance of the tegument surface of schistosomes was first described in 1973, in one of the earliest volumes of the International Journal for Parasitology. The present review, published almost 50 years later, traces the development of our knowledge of the tegument, starting with those earliest cytological advances, particularly the surface plasma membrane-membranocalyx complex, through an era of protein discovery to the modern age of protein characterization, aided by proteomics. More recently, analysis of single cell transcriptomes of schistosomes is providing insight into the organisation of the cell bodies that support the surface syncytium. Our understanding of the tegument, notably the nature of the proteins present within the plasma membrane and membranocalyx, has provided insights into how the schistosomes interact with their hosts but many aspects of how the tegument functions remain unanswered. Among the unresolved aspects are those concerned with maintenance and renewal of the surface membrane complex, and whether surface proteins and membrane components are recycled. Current controversies arising from investigations about whether the tegument is a source of extracellular vesicles during parasitism, and if it is covered with glycolytic enzymes, are evaluated in the light of cytological and proteomic knowledge of the layer.

Schistosomiasis with a Focus on Africa.

Schistosomiasis is a common neglected tropical disease of impoverished people and livestock in many developing countries in tropical Africa, the Middle East, Asia, and Latin America. Substantial progress has been made in controlling schistosomiasis in some African countries, but the disease still prevails in most parts of sub-Saharan Africa with an estimated 800 million people at risk of infection. Current control strategies rely primarily on treatment with praziquantel, as no vaccine is available; however, treatment alone does not prevent reinfection. There has been emphasis on the use of integrated approaches in the control and elimination of the disease in recent years with the development of health infrastructure and health education. However, there is a need to evaluate the present status of African schistosomiasis, primarily caused by Schistosoma mansoni and S. haematobium, and the factors affecting the disease as the basis for developing more effective control and elimination strategies in the future. This review provides an historical perspective of schistosomiasis in Africa and discusses the current status of control efforts in those countries where the disease is endemic.

Perceptions of dog owners towards canine gastrointestinal parasitism and associated human health risk in Southeast Queensland.

Canine companion animals can carry a number of zoonotic parasites which can adversely impact both human and animal health. Previous studies in Australia indicated that while parasitic infections in dogs are still common and there is variability in the awareness and perception of zoonotic risks among pet owners, the likely contribution of sociodemographic factors to the variation in awareness and perception needs to be further explored. The primary objective of this study is to quantify the relationship between dog owners' knowledge and beliefs about dog parasites and their sociodemographic characteristics. In this study, we surveyed a total of 281 dog owners in SE Queensland between April 2019 to March 2020 and the relationship between dog owners' perception of gastrointestinal parasite infection was assessed using an adaptation of the Health Belief Model, social cognitive framework for health protection. The model looked into the role of dog owners' demography on their perceived severity and susceptibility to zoonotic canine parasites and their likelihood of performing actions associated with worm control of their pets. Our results indicate that owners perceptions about parasitic disease severity in their pets was 26% higher in female dog owners compared to males, in respondents owning dogs over 10 years (27% higher than those owning a dog <3 years) and those owners that regularly deworm their pets and report faeces disposal. Our study indicates that the perceptions of pet owners towards zoonotic canine parasites varies demographically and owner education is important to prevent infection among dogs and control the zoonotic transmission to owners and the community. Finally, there was evidence that increased frequency of visits to veterinary clinics can increase the likelihood of owners performing worm treatment, proper faecal disposal, and cooking meat before feeding it to dogs.

Innovations and Advances in Schistosome Stem Cell Research.

Schistosomes infect about 250 million people globally causing the devastating and persistent disease of schistosomiasis. These blood flukes have a complicated life cycle involving alternating infection of freshwater snail intermediate and definitive mammalian hosts. To survive and flourish in these diverse environments, schistosomes transition through a number of distinct life-cycle stages as a result of which they change their body plan in order to quickly adapt to each new environment. Current research suggests that stem cells, present in adults and larvae, are key in aiding schistosomes to facilitate these changes. Given the recent advances in our understanding of schistosome stem cell biology, we review the key roles that two major classes of cells play in the different life cycle stages during intramolluscan and intramammalian development; these include the germinal cells of sporocysts involved in asexual reproduction in molluscan hosts and the neoblasts of adult worms involved in sexual reproduction in human and other mammalian hosts. These studies shed considerable new light in revealing the stem cell heterogeneity driving the propagation of the schistosome life cycle. We also consider the possibility and value of establishing stem cell lines in schistosomes to advance schistosomiasis research. The availability of such self-renewable resources will provide new platforms to study stem cell behavior and regulation, and to address fundamental aspects of schistosome biology, reproductive development and survival. In turn, such studies will create new avenues to unravel individual gene function and to optimize genome-editing processes in blood flukes, which may lead to the design of novel intervention strategies for schistosomiasis.

A unique group of scabies mite pseudoproteases promotes cutaneous blood coagulation and delays plasmin-induced fibrinolysis.

BACKGROUND: Scabies, a highly contagious skin disease affecting more than 200 million people worldwide at any time, is caused by the parasitic mite Sarcoptes scabiei. In the absence of molecular markers, diagnosis requires experience making surveillance and control challenging. Superficial microthrombi in the absence of vasculitis in scabies-affected skin are a recognised, yet unexplained histopathological differential of scabies infection. This study demonstrates that a family of Scabies Mite Inactivated Cysteine Protease Paralogues (SMIPP-Cs) excreted by the mites plays a role in formation of scabies-induced superficial microthrombi. METHODOLOGY/PRINCIPAL FINDINGS: A series of in vitro and ex vivo experiments involving two representative recombinant SMIPP-Cs was carried out. In the presence of SMIPP-Cs, the thrombin clotting time (TCT), fibrin formation and plasmin induced fibrinolysis were monitored in vitro. The ultrastructure of the SMIPP-C-modulated fibrin was analysed by Scanning Electron Microscopy (SEM). Immuno-histological analyses were performed ex vivo, to localise the SMIPP-C proteins within scabies infected skin biopsies. SMIPP-Cs displayed pro-coagulant properties. They bound calcium ions, reduced the thrombin clotting time, enhanced the fibrin formation rate and delayed plasmin-induced fibrinolysis. The SMIPP-Cs associated with fibrin clots during fibrinogen polymerisation and did not bind to preformed fibrin. Scanning electron microscopy revealed that the fibrin clots formed in the presence of SMIPP-Cs were aberrant and denser than normal fibrin clots. SMIPP-Cs were detected in microthrombi which are commonly seen in scabietic skin. CONCLUSIONS/SIGNIFICANCE: The SMIPP-Cs are the first scabies mite proteins found in sub-epidermal skin layers and their pro-coagulant properties promote superficial microthrombi formation in scabetic skin. Further research is needed to evaluate their potential as diagnostic or therapeutic target.