scholarly journals A combined transcriptomic approach to identify candidates for an anti-tick vaccine blocking B. afzelii transmission

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jos J. A. Trentelman ◽  
Radek Sima ◽  
Nicolas Krezdorn ◽  
Julen Tomás-Cortázar ◽  
Diego Barriales ◽  
...  
Keyword(s):  
Ixodes Scapularis ◽  
Protein A ◽  
Tick Feeding ◽  
Infected Tick ◽  
Vaccine Candidates ◽  
Successful Infection ◽  
Potential Pathogen ◽  
The Usa ◽  
Tail Protein ◽  
Tick Vaccine

AbstractIxodes ricinus is the vector for Borrelia afzelii, the predominant cause of Lyme borreliosis in Europe, whereas Ixodes scapularis is the vector for Borrelia burgdorferi in the USA. Transcription of several I. scapularis genes changes in the presence of B. burgdorferi and contributes to successful infection. To what extend B. afzelii influences gene expression in I. ricinus salivary glands is largely unknown. Therefore, we measured expression of uninfected vs. infected tick salivary gland genes during tick feeding using Massive Analysis of cDNA Ends (MACE) and RNAseq, quantifying 26.179 unique transcripts. While tick feeding was the main differentiator, B. afzelii infection significantly affected expression of hundreds of transcripts, including 465 transcripts after 24 h of tick feeding. Validation of the top-20 B. afzelii-upregulated transcripts at 24 h of tick feeding in ten biological genetic distinct replicates showed that expression varied extensively. Three transcripts could be validated, a basic tail protein, a lipocalin and an ixodegrin, and might be involved in B. afzelii transmission. However, vaccination with recombinant forms of these proteins only marginally altered B. afzelii infection in I. ricinus-challenged mice for one of the proteins. Collectively, our data show that identification of tick salivary genes upregulated in the presence of pathogens could serve to identify potential pathogen-blocking vaccine candidates.

scholarly journals Antibodies against EGF-like domains in Ixodes scapularis BM86 orthologs impact tick feeding and survival of Borrelia burgdorferi

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juraj Koči ◽  
Sandhya Bista ◽  
Payal Chirania ◽  
Xiuli Yang ◽  
Chrysoula Kitsou ◽  
...  
Keyword(s):  
Rna Interference ◽  
Growth Factor ◽  
Borrelia Burgdorferi ◽  
Ixodes Scapularis ◽  
Biological Significance ◽  
Sensu Stricto ◽  
Tick Feeding ◽  
Epidermal Growth ◽  
Tick Vaccine ◽  
Multiple Pathogens

AbstractIxodes scapularis ticks transmit multiple pathogens, including Borrelia burgdorferi sensu stricto, and encode many proteins harboring epidermal growth factor (EGF)-like domains. We show that I. scapularis produces multiple orthologs for Bm86, a widely studied tick gut protein considered as a target of an anti-tick vaccine, herein termed as Is86. We show that Is86 antigens feature at least three identifiable regions harboring EGF-like domains (termed as EGF-1, EGF-2, and EGF-3) and are differentially upregulated during B. burgdorferi infection. Although the RNA interference-mediated knockdown of Is86 genes did not show any influences on tick engorgement or B. burgdorferi sensu stricto persistence, the immunization of murine hosts with specific recombinant EGF antigens marginally reduced spirochete loads in the skin, in addition to affecting tick blood meal engorgement and molting. However, given the borderline impact of EGF immunization on tick engorgement and pathogen survival in the vector, it is unlikely that these antigens, at least in their current forms, could be developed as potential vaccines. Further investigations of the biological significance of Is86 (and other tick antigens) would enrich our knowledge of the intricate biology of ticks, including their interactions with resident pathogens, and contribute to the development of anti-tick measures to combat tick-borne illnesses.

scholarly journals An efficient microinjection method to generate human anaplasmosis agent Anaplasma phagocytophilum-infected ticks

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vikas Taank ◽  
Ellango Ramasamy ◽  
Hameeda Sultana ◽  
Girish Neelakanta
Keyword(s):  
Anaplasma Phagocytophilum ◽  
Ixodes Scapularis ◽  
In Vitro Cultures ◽  
Transmission Dynamics ◽  
Tick Feeding ◽  
Nymphal Stage ◽  
Bacterial Colony ◽  
Obligate Intracellular ◽  
Transstadial Transmission

Abstract Ticks are important vectors that transmit several pathogens including human anaplasmosis agent, Anaplasma phagocytophilum. This bacterium is an obligate intracellular rickettsial pathogen. An infected reservoir animal host is often required for maintenance of this bacterial colony and as a source for blood to perform needle inoculations in naïve animals for tick feeding studies. In this study, we report an efficient microinjection method to generate A. phagocytophilum-infected ticks in laboratory conditions. The dense-core (DC) form of A. phagocytophilum was isolated from in vitro cultures and injected into the anal pore of unfed uninfected Ixodes scapularis nymphal ticks. These ticks successfully transmitted A. phagocytophilum to the murine host. The bacterial loads were detected in murine blood, spleen, and liver tissues. In addition, larval ticks successfully acquired A. phagocytophilum from mice that were previously infected by feeding with DC-microinjected nymphal ticks. Transstadial transmission of A. phagocytophilum from larvae to nymphal stage was also evident in these ticks. Taken together, our study provides a timely, rapid, and an efficient method not only to generate A. phagocytophilum-infected ticks but also provides a tool to understand acquisition and transmission dynamics of this bacterium and perhaps other rickettsial pathogens from medically important vectors.

Range expansion of Ixodes scapularis in the USA.

2021 ◽  
pp. 176-182
Author(s):  
Durland Fish
Keyword(s):  
Range Expansion ◽  
Ixodes Scapularis ◽  
The Usa ◽  
History Of

Abstract This chapter covers the history of Ixodes scapularis, its mode and major pathways of range expansion, and the establishment of I. scapularis-borne pathogens in the USA.

scholarly journals Prevalence and diversity of piroplasms and ticks in young raccoons and an association of Babesia sensu stricto infections with splenomegaly

2018 ◽  
Vol 4 ◽  
Author(s):  
Kayla Buck Garrett ◽  
Renee Schott ◽  
Lea Peshock ◽  
Michael J. Yabsley
Keyword(s):  
Vertical Transmission ◽  
Disease Risk ◽  
Ixodes Scapularis ◽  
Dermacentor Variabilis ◽  
Sensu Stricto ◽  
Ixodid Ticks ◽  
Babesia Microti ◽  
Alternative Route ◽  
The Usa ◽  
History Of

AbstractPiroplasms are intraerythrocytic parasites that are often transmitted by ixodid ticks, but vertical transmission is an alternative route for some species. In the USA, raccoons (Procyon lotor) are hosts for two known species, a Babesia microti-like sp. and Babesia lotori (in Babesia sensu stricto group). To better understand the natural history of Babesia in raccoons, we tested young raccoons from Minnesota and Colorado for Babesia spp., examined them for ticks, and assessing for splenomegaly as a sign of clinical disease. Raccoons from both states were infected with B. microti-like sp. and Babesia sensu stricto spp. Infections of B. microti-like were common, even in 1-week-old raccoons, suggesting vertical transmission. Babesia sensu stricto infections were more common in older raccoons. Raccoons infected with Babesia sensu stricto had significantly higher spleen:body weight ratios compared with uninfected or B. microti-like sp.-infected raccoons. Ticks were only found on raccoons from Minnesota. The most common and abundant tick was Ixodes texanus but Ixodes scapularis and Dermacentor variabilis were also found on raccoons. We report piroplasm infections and infestations with several tick species in very young raccoons. Young raccoons infected with Babesia sensu stricto spp. had higher spleen:body weight ratios, suggesting a disease risk.

scholarly journals Construction and characterization of infectious cDNA clones of a chicken strain of hepatitis E virus (HEV), avian HEV

2005 ◽  
Vol 86 (9) ◽  
pp. 2585-2593 ◽  
Author(s):  
F. F. Huang ◽  
F. W. Pierson ◽  
T. E. Toth ◽  
X. J. Meng
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Cdna Clones ◽  
Virus Shedding ◽  
Rna Transcripts ◽  
Successful Infection ◽  
The Usa ◽  
Avian Hev

Hepatitis E virus (HEV), the causative agent of hepatitis E, is an important human pathogen. Increasing evidence indicates that hepatitis E is a zoonosis. Avian HEV was recently discovered in chickens with hepatitis–splenomegaly syndrome in the USA. Like swine HEV from pigs, avian HEV is also genetically and antigenically related to human HEV. The objective of this study was to construct and characterize an infectious cDNA clone of avian HEV for future studies of HEV replication and pathogenesis. Three full-length cDNA clones of avian HEV, pT7-aHEV-5, pT7G-aHEV-10 and pT7G-aHEV-6, were constructed and their infectivity was tested by in vitro transfection of leghorn male hepatoma (LMH) chicken liver cells and by direct intrahepatic inoculation of specific-pathogen-free (SPF) chickens with capped RNA transcripts from the three clones. The results showed that the capped RNA transcripts from each of the three clones were replication competent when transfected into LMH cells as demonstrated by detection of viral antigens with avian HEV-specific antibodies. SPF chickens intrahepatically inoculated with the capped RNA transcripts from each of the three clones developed active avian HEV infections as evidenced by seroconversion to avian HEV antibodies, viraemia and faecal virus shedding. The infectivity was further confirmed by successful infection of naïve chickens with the viruses recovered from chickens inoculated with the RNA transcripts. The results indicated that all three cDNA clones of avian HEV are infectious both in vitro and in vivo. The availability of these infectious clones for a chicken strain of HEV now affords an opportunity to study the mechanisms of HEV cross-species infection and tissue tropism by constructing chimeric viruses among human, swine and avian HEVs.

scholarly journals Detection of antibodies to decorin-binding protein A (DbpA) and DbpB after infection of dogs with Borrelia burgdorferi by tick challenge

2020 ◽  
Vol 32 (3) ◽  
pp. 481-485
Author(s):  
Darby G. Oldenburg ◽  
Dean A. Jobe ◽  
Steven D. Lovrich ◽  
Rhonda L. LaFleur ◽  
Douglas W. White ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Ixodes Scapularis ◽  
Binding Protein ◽  
Protein A ◽  
Immune Serum ◽  
Immunoglobulin M ◽  
Antibody Responses ◽  
Igg Antibodies ◽  
Serum Samples

We characterized the antibody response to decorin-binding protein A (DbpA) or DbpB from immune serum samples collected from 27 dogs infected with Borrelia burgdorferi by Ixodes scapularis ticks. Immunoglobulin M (IgM) antibodies to DbpA or DbpB were rarely detected, but high levels of IgG antibodies to DbpA were detected in 16 of 27 of the immune sera collected 1 mo after infection, 20 of 25 of the sera collected after 2 mo, and each of the 23, 17, or 11 serum samples evaluated after 3, 4, or 5 mo, respectively. In addition, IgG antibodies to DbpB were detected in 22 of 27 ( p = 0.005) tested dogs after 1 mo, and the frequency of detecting the antibodies thereafter closely mimicked the antibody responses to DbpA. Moreover, antibodies to DbpA or DbpB were not produced by dogs vaccinated with a whole-cell B. burgdorferi bacterin; removing the antibodies to DbpA by adsorption to recombinant DbpA (rDbpA) did not affect the reactivity detected by a rDbpB ELISA. Therefore, the findings from our preliminary study showed that antigenically distinct antibodies to DbpA or DbpB are produced reliably during canine infection with B. burgdorferi, and the response is not confounded by vaccination with a Lyme disease bacterin. Larger studies are warranted to more critically evaluate whether detecting the antibody responses can improve serodiagnostic confirmation of canine Lyme disease.

Babesiosis and malaria

2011 ◽  
Author(s):  
F. E. G. Cox
Keyword(s):  
Ixodes Scapularis ◽  
Life Cycles ◽  
Molecular Techniques ◽  
Babesia Microti ◽  
Babesia Divergens ◽  
The World ◽  
Causative Agents ◽  
The Usa ◽  
Human Infections ◽  
Human Babesiosis

Babesiosis and malaria are rare zoonoses that, with new developments in diagnosis and the application of molecular techniques, are becoming increasingly frequently recognised. Babesia species infect millions of cattle and unknown numbers of sheep, dogs, horses, and wildlife throughout the world but human infections are very uncommon. There are two distinct forms of human babesiosis. In Europe the causative agent is Babesia divergens, a natural parasite of cattle transmitted by the tick Ixodes ricinis. B. divergens infections in humans are extremely rare and nearly all have been recorded from asplenic or otherwise immunocompromised patients. In the USA, human babesiosis is more common than in Europe, although still very rare, and is not restricted to immunocompromised individuals. The causative agents are Babesia microti and B. duncani, common parasites of rodents, transmitted by the tick Ixodes scapularis. In addition there have been sporadic reports of human babesiosis from other parts of the world but in most cases the species of Babesia involved has not been characterised. Malaria parasites and Babesia both inhabit red blood cells during part of their life cycles and these stages cause the diseases, malaria and babesiosis, which are similar in many respects. The facts that humans can occasionally acquire malaria and babesiosis from animals, that both parasites appear similar when seen in blood films and that both cause similar symptoms can cause problems in diagnosis and these rare infections are, therefore, of interest to clinicians and epidemiologists.

scholarly journals Preliminary Work Towards Finding Proteins as Potential Vaccine Candidates for Vibrio cholerae Pakistani Isolates through Reverse Vaccinology

Medicina ◽  
2019 ◽  
Vol 55 (5) ◽  
pp. 195 ◽  
Author(s):  
Samia Zeb ◽  
Amjad Ali ◽  
Sardar Muhammad Gulfam ◽  
Habib Bokhari
Keyword(s):  
Vibrio Cholerae ◽  
Tertiary Structure ◽  
Diarrheal Disease ◽  
Vaccine Development ◽  
Protein A ◽  
Reverse Vaccinology ◽  
Whole Genome Sequence ◽  
Effective Vaccine ◽  
Vaccine Candidates ◽  
Potential Vaccine

Background and Objective: Vibrio cholerae continues to emerge as a dangerous pathogen because of increasing resistance to a number of antibiotics. This paper provides a solution to emerging antibiotic resistance by introducing novel proteins as vaccine candidates against cholera. Materials and Methods: Vibrio cholerae genome versatility is a hurdle for developing a vaccine to combat diarrhoeal infection, so its core gene information was used to determine a potential vaccine candidate. Whole genome sequence data of more than 100 Vibrio cholerae strains were used simultaneously to get core genome information. The VacSol pipeline based on reverse vaccinology was selected to address the problem of safe, cheap, temperature-stable, and effective vaccine candidates which can be used for vaccine development against Vibrio cholerae. VacSol screens vaccine candidates using integrated, well-known, and robust algorithms/tools for proteome analysis. The proteomes of the pathogens were initially screened to predict homology using BLASTp. Proteomes that are non-homologous to humans are then subjected to a predictor for localization. Helicer predicts transmembrane helices for the protein. Proteins failing to comply with the set parameters were filtered at each step, and finally, 11 proteins were filtered as vaccine candidates. Results: This selected group of vaccine candidates consists of proteins from almost all structural parts of Vibrio cholerae. Their blast results show that this filtered group includes flagellin A protein, a protein from the Zn transporter system, a lipocarrier outer membrane protein, a peptidoglycan-associated protein, a DNA-binding protein, a chemotaxis protein, a tRNA Pseuriudine synthase A, and two selected proteins, which were beta lactamases. The last two uncharacterized proteins possess 100% similarity to V. albensis and Enterobacter, respectively. Tertiary structure and active site determination show a large number of pockets on each protein. Conclusions: The most interesting finding of this study is that 10 proteins out of 11 filtered proteins are introduced as novel potential vaccine candidates. These novel vaccine candidates can result in the development of cost-effective and broad-spectrum vaccines which can be used in countries where cholera is a major contributor to diarrheal disease.

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