Tick-borne encephalitis virus (TBEV) is flavivirus transmitted to the host via tick saliva which contains various molecules with biological impacts. One of such molecules is Iristatin, a cysteine protease inhibitor from Ixodes ricinus that has been shown to have immunomodulatory properties. To characterize Iristatin in the relation to TBEV, we investigate whether this tick inhibitor has any capacity to influence TBEV infection. Mice were intradermally infected by TBEV with or without Iristatin and the viral multiplication was determined in skin and brain tissues by RT-PCR two and 5 days after infection. The viral RNA was detected in both intervals in skin and increased by time. The application of Iristatin caused a reduction in viral RNA in skin but not in the brain of infected mice 5 days post-infection. Moreover, anti-viral effect of Iristatin on skin was accompanied by a significant decline of interferon-stimulated gene 15 gene expression. The effect of Iristatin on TBEV replication was tested also in vitro in primary macrophages and dendritic cells; however, no changes were observed suggesting no direct interference of Iristatin with virus replication. Still, the Iristatin caused a suppression of Erk1/2 phosphorylation in TBEV-infected dendritic cells and had the anti-apoptotic effect. This is the first report showing that a tick cystatin decreases the viral RNA in the host skin, likely indirectly through creating skin environment that is less supportive for TBEV replication. Assuming, that viral RNA reflects the amount of infectious virus, decline of TBEV in host skin could influence the tick biology or virus transmission during cofeeding.
- MeSH
- antivirové látky farmakologie MeSH
- cystatiny farmakologie metabolismus genetika MeSH
- dendritické buňky virologie účinky léků MeSH
- klíště * virologie účinky léků MeSH
- klíšťová encefalitida * virologie MeSH
- kůže * virologie MeSH
- makrofágy virologie MeSH
- mozek virologie metabolismus MeSH
- myši MeSH
- replikace viru * účinky léků MeSH
- RNA virová genetika MeSH
- slinné cystatiny metabolismus MeSH
- viry klíšťové encefalitidy * účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Lyme disease, a tick-borne illness caused by Borrelia spirochetes, poses a significant threat to public health. While acaricides effectively control ticks on pets and livestock, their impact on pathogen transmission is often unclear. This study investigated the acaricidal efficacy of fipronil against Ixodes ricinus ticks and its potential to block Borrelia afzelii transmission. Initially, we employed the ex vivo membrane blood-feeding system to assess the dose–response acaricidal activity of ivermectin, fipronil and its metabolite fipronil sulfone, when supplemented in the blood meal throughout tick feeding. To obtain the temporal resolution of their acaricidal activity, ticks were allowed to initiate blood feeding on an artificial membrane before being exposed to a 1-time topical application of these acaricides. Fipronil demonstrated superior speed of acaricidal activity, with onset of tick moribundity within a few hours, prompting its selection for further in vivo testing with Borrelia-infected ticks. The I. ricinus nymphs infected with B. afzelii were topically treated with fipronil shortly after attachment to mice. Four weeks post-feeding, the skin and internal organs were examined for the presence of Borrelia. No spirochetes were detected in any organ of mice exposed to fipronil-treated ticks, while 9 out of 10 control mice, exposed to non-treated infectious ticks, displayed Borrelia infection. The in vitro co-culture experiments confirmed that fipronil had no direct effect on Borrelia viability, indicating a tick-directed effect. Overall, these results underline the potential of fipronil as a valuable tool for tick control strategies and suggest a concept for acaricide-mediated Borrelia-transmission blockers.
- MeSH
- akaricidy * farmakologie MeSH
- Borrelia burgdorferi komplex účinky léků fyziologie MeSH
- klíště * mikrobiologie účinky léků MeSH
- lymeská nemoc * prevence a kontrola přenos mikrobiologie MeSH
- myši MeSH
- nymfa mikrobiologie účinky léků MeSH
- pyrazoly * farmakologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Ixodes 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.
- MeSH
- arachnida jako vektory mikrobiologie MeSH
- bakteriální vakcíny aplikace a dávkování MeSH
- Borrelia burgdorferi komplex účinky léků MeSH
- infestace klíšťaty genetika mikrobiologie prevence a kontrola přenos MeSH
- klíště účinky léků MeSH
- lymeská nemoc genetika mikrobiologie prevence a kontrola přenos MeSH
- myši MeSH
- proteiny členovců genetika MeSH
- slinné žlázy mikrobiologie MeSH
- transkriptom * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- Anoplura růst a vývoj účinky léků MeSH
- Argas růst a vývoj MeSH
- Ctenocephalides růst a vývoj účinky léků MeSH
- Culicidae růst a vývoj MeSH
- infestace roztoči * ošetřování přenos prevence a kontrola MeSH
- klíště růst a vývoj účinky léků MeSH
- komáří přenašeči klasifikace patogenita účinky léků MeSH
- kousnutí a bodnutí hmyzem ošetřování prevence a kontrola MeSH
- kousnutí klíštětem prevence a kontrola MeSH
- lidé MeSH
- Pediculus růst a vývoj účinky léků MeSH
- roztoči anatomie a histologie klasifikace patogenita MeSH
- Sarcoptes scabiei růst a vývoj MeSH
- štěnice růst a vývoj MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
V této studii jsme zhodnotili a porovnali repelentní účinek tří esenciálních olejů, které jsou často považovány zašetrnou a ekologickou alternativu k syntetickým repelentům. Jejich účinnost na klíště obecné (Ixodesricinus) je ale negativně ovlivněna vysokou těkavostí. Účinnost jsme porovnali se syntetickým repelentem DEET (N,N-diethyl-m-toluamid). Repelentní účinek byl zjištěn u všech testovaných látek, ale v průběhu pokusu se účinekukázal jako časově nestabilní. 5 minut po aplikaci se repelentní efekt pohyboval v rozmezí 65–85 %, po 80 mi-nutách, kdy byl pokus ukončen, byla repelence levandulového oleje 45 % a eukalyptového oleje 15 %. Pomerančový esenciální olej byl proti klíšťatům neúčinný již po 20 minutách od aplikace. Naopak účinek syntetického DEETu byl po celou dobu studie vysoký (95–100 %). V případě levandulového esenciálního oleje se ukázalo, že může být považován za vhodný repelent pro pobyt v terénu trvající kratší dobu.
This study evaluated the repellent effect of three essential oils against females of Ixodes ricinus, which is consider-ed the main arthropod disease vector in Europe. The essential oils could be regarded to be ecological and healthyalternatives to synthetic repellents, whose effect is unfortunately negatively influenced by high volatility. Asa comparison sample, 10% DEET was used. The tested essential oils exhibited a moderate to high initial repellen-cy of 65%–85% five minutes after application. The bioassay was terminated after 80 min, when the repellent effects of lavender and eucalyptus oils were 45% and 15%, respectively. No effect of orange oil was observed aftera 20-min mark. Conversely, the effect of DEET was determined to be high and stable (95–100%) throughout the experiment. This study found that the oils tested are not as effective as DEET. On the other hand, lavender oil has shown an interesting potential as an alternative repellent for outdoor activities of shorter duration.
Arthropods are dangerous vectors of agents of deadly diseases, which may hit as epidemics or pandemics in the increasing world population of humans and animals. Among them, ticks transmit more pathogen species than any other group of blood-feeding arthropods worldwide. Thus, the effective and eco-friendly control of tick vectors in a constantly changing environment is a crucial challenge. A number of novel routes have been attempted to prevent and control tick-borne diseases, including the development of (i) vaccines against viruses vectored by ticks; (ii) pheromone-based control tools, with special reference to the "lure and kill" techniques; (iii) biological control programmes relying on ticks' natural enemies and pathogens; and (iv) the integrated pest management practices aimed at reducing tick interactions with livestock. However, the extensive employment of acaricides and tick repellents still remains the two most effective and ready-to-use strategies. Unfortunately, the first one is limited by the rapid development of resistance in ticks, as well as by serious environmental concerns. On the other hand, the exploitation of plants as sources of effective tick repellents is often promising. Here, we reviewed current knowledge concerning the effectiveness of plant extracts as acaricides or repellents against tick vectors of public health importance, with special reference to Ixodes ricinus, Ixodes persulcatus, Amblyomma cajennense, Haemaphysalis bispinosa, Haemaphysalis longicornis, Hyalomma anatolicum, Hyalomma marginatum rufipes, Rhipicephalus appendiculatus, Rhipicephalus (Boophilus) microplus, Rhipicephalus pulchellus, Rhipicephalus sanguineus and Rhipicephalus turanicus. Eighty-three plant species from 35 botanical families were selected. The most frequent botanical families exploited as sources of acaricides and repellents against ticks were Asteraceae (15 % of the selected studies), Fabaceae (9 %), Lamiaceae (10 %), Meliaceae (5 %), Solanaceae (6 %) and Verbenaceae (5 %). Regression equation analyses showed that the literature grew by approximately 20 % per year (period: 2005-2015). Lastly, in the final section, insights for future research are discussed. We focused on some caveats for future data collection and analysis. Current critical points mainly deal with (a) not uniform methods used, which prevent proper comparison of the results; (b) inaccurate tested concentrations, frequently 100 % concentration corresponded to the gross extract, where the exact amounts of extracted substances are unknown; and (c) not homogeneous size of tested tick instars and species. Overall, the knowledge summarized in this review may be helpful for comparative screening among extensive numbers of plant-borne preparations, in order to develop newer and safer tick control tools.
- MeSH
- akaricidy farmakologie MeSH
- Asteraceae chemie MeSH
- dobytek MeSH
- Fabaceae chemie MeSH
- hluchavkovité chemie MeSH
- infekce přenášené vektorem MeSH
- klíště účinky léků MeSH
- kontrola klíšťat metody MeSH
- nemoci přenášené klíšťaty prevence a kontrola MeSH
- Rhipicephalus sanguineus účinky léků MeSH
- rostlinné extrakty farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The ever-increasing number of Lyme borreliosis patients led us to consider more effective procedures for disease prevention. The aim of our study was to monitor the annual activity and infectivity of Ixodes ricinus ticks in the Pisárky region, City of Brno, CR, and to test the responses of the locally-captured ticks to selected repellents. The result of regular one-hour-per-week monitoring in 2011 was the collection of ticks that directly reflected the highest number of Lyme disease patients (4,835) detected throughout the period of recording in the Czech Republic. The ticks were examined for spirochaetes by dark field microscopy. The positive samples were identified by PCR analysis, confirming that 76% of these were infected with Borrelia burgdorferi sensu lato. Ticks were most abundant in May and June, with August having the highest risk for spirochaetal infection. Tick activity was statistically correlated with temperature. The moving-object-bioassay was used to study repellent efficiency on the Ixodes ricinus nymphs captured in the above-mentioned suburban park. Five selected commercial repellents based on DEET (N, N-diethyl-3-thylbenzamide) showed statistically different effects on the non-repellent control group.
- MeSH
- klíště účinky léků genetika fyziologie MeSH
- lymeská nemoc prevence a kontrola přenos MeSH
- repelenty proti hmyzu farmakologie MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- Klíčová slova
- PERIPEL 55, PERMANONE,
- MeSH
- Aedes účinky léků MeSH
- insekticidy farmakologie MeSH
- klíště účinky léků MeSH
- moucha domácí účinky léků MeSH
- repelenty proti hmyzu farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
