Highly prevalent Coxiella sp. bacterium in the tick vector Amblyomma americanum.
Ontology highlight
ABSTRACT:
SUBMITTER: Jasinskas A
PROVIDER: S-EPMC1797106 | biostudies-literature | 2007 Jan
REPOSITORIES: biostudies-literature
Publications
Highly prevalent Coxiella sp. bacterium in the tick vector Amblyomma americanum.
Jasinskas Algimantas A Zhong Jianmin J Barbour Alan G AG
Applied and environmental microbiology 20061103 1
Laboratory-reared and field-collected Amblyomma americanum ticks were hosts of a Coxiella sp. and a Rickettsia sp. While the Coxiella sp. was detected in 50 of 50 field-collected ticks, the Rickettsia sp. was absent from 32% of ticks. The Coxiella sp. showed evidence of a reduced genome and may be an obligate endosymbiont. ...[more]
Similar Datasets
Project description:BackgroundThe lone star tick Amblyomma americanum is a common pest and vector of infectious diseases for humans and other mammals in the southern and eastern United States. A Coxiella sp. bacterial endosymbiont was highly prevalent in both laboratory-reared and field-collected A. americanum. The Coxiella sp. was demonstrated in all stages of tick and in greatest densities in nymphs and adult females, while a Rickettsia sp. was less prevalent and in lower densities when present.Methodology/principal findingsWe manipulated the numbers of both bacterial species in laboratory-reared A. americanum by injecting engorged nymphs or engorged, mated females with single doses of an antibiotic (rifampin or tetracycline) or buffer alone. Burdens of the bacteria after molting or after oviposition were estimated by quantitative polymerase chain reaction with primers and probes specific for each bacterial species or, as an internal standard, the host tick. Post-molt adult ticks that had been treated with rifampin or tetracycline had lower numbers of the Coxiella sp. and Rickettsia sp. and generally weighed less than ticks that received buffer alone. Similarly, after oviposition, females treated previously with either antibiotic had lower burdens of both bacterial species in comparison to controls. Treatment of engorged females with either antibiotic was associated with prolonged time to oviposition, lower proportions of ticks that hatched, lower proportions of viable larvae among total larvae, and lower numbers of viable larvae per tick. These fitness estimators were associated with reduced numbers of the Coxiella sp. but not the Rickettsia sp.Conclusion/significanceThe findings indicate that the Coxiella sp. is a primary endosymbiont, perhaps provisioning the obligately hematophagous parasites with essential nutrients. The results also suggest that antibiotics could be incorporated into an integrated pest management plan for control of these and other tick vectors of disease.
| S-EPMC1852332 | biostudies-literature
Project description:A Coxiella-type microbe occurs at 100% frequency in all Amblyomma americanum ticks thus far tested. Using laboratory-reared ticks free of other microbes, we identified the Amblyomma-associated Coxiella microbe in several types of tissue and at various stages of the life cycle of A. americanum by 16S rRNA gene sequencing and diagnostic PCR. We visualized Amblyomma-associated Coxiella through the use of a diagnostic fluorescence in situ hybridization (FISH) assay supplemented with PCR-based detection, nucleic acid fluorescent staining, wide-field epifluorescence and confocal microscopy, and transmission electron microscopy (TEM). Specific fluorescent foci were observed in several tick tissues, including the midgut and the Malpighian tubules, but particularly bright signals were observed in the granular acini of salivary gland clusters and in both small and large oocytes. TEM confirmed intracellular bacterial structures in the same tissues. The presence of Amblyomma-associated Coxiella within oocytes is consistent with the vertical transmission of these endosymbionts. Further, the presence of the Amblyomma-associated Coxiella symbiont in other tissues such as salivary glands could potentially lead to interactions with horizontally acquired pathogens.
| S-EPMC2075054 | biostudies-literature
Project description:Amblyomma americanum tick serine protease inhibitor (serpin, AAS) 19, is a highly conserved protein that is characterized by its functional domain being 100% conserved across tick species. We also reported that AAS19 was an immunogenic tick saliva protein with anti-haemostatic functions and an inhibitor of trypsin-like proteases including five of the eight serine protease factors in the blood clotting cascade. In this study the goal was to validate the importance of AAS19 in A. americanum tick physiology, assess immunogenicity and investigate tick vaccine efficacy of yeast-expressed recombinant (r) AAS19. We confirm that AAS19 is important to A. americanum fitness and blood meal feeding. AAS19 mRNA disruption by RNAi silencing caused ticks to obtain blood meals that were 50% smaller than controls, and treated ticks being morphologically deformed with 100% of the deformed ticks dying in incubation. We show that rAAS19 is highly immunogenic in that two 500 μg inoculations mixed with TiterMax Gold adjuvant provoked antibody titers of more than 1:320,000 that specifically reacted with native AAS19 in unfed and partially fed tick tissue. Since AAS19 is injected into animals during tick feeding, we challenge infested immunized rabbits twice to test if tick infestations of immunized rabbits could act as booster. While in the first infestation significantly smaller tick blood meals were observed on one of the two immunized rabbits, smaller blood meals were observed on both rabbits, but 60% of ticks that engorged on immunized rabbits in the second infestation failed to lay eggs. It is notable that ticks fed faster on immunized animals despite obtaining smaller blood meals. We conclude that rAAS19 is a potential component of cocktail tick vaccine.
| S-EPMC4788537 | biostudies-literature
Project description:BackgroundThe lone star tick (Amblyomma americanum), an important vector of a wide range of human and animal pathogens, is very common throughout the East and Midwest of the USA. Ticks are known to carry non-pathogenic bacteria that may play a role in their vector competence for pathogens. Several previous studies using the high throughput sequencing (HTS) technologies reported the commensal bacteria in a tick midgut as abundant and diverse. In contrast, in our preliminary survey of the field collected adult lone star ticks, we found the number of culturable/viable bacteria very low.MethodsWe aimed to analyze the bacterial community of A. americanum by a parallel culture-dependent and a culture-independent approach applied to individual ticks.ResultsWe analyzed 94 adult females collected in eastern Kansas and found that 60.8% of ticks had no culturable bacteria and the remaining ticks carried only 67.7 ± 42.8 colony-forming units (CFUs)/tick representing 26 genera. HTS of the 16S rRNA gene resulted in a total of 32 operational taxonomic units (OTUs) with the dominant endosymbiotic genera Coxiella and Rickettsia (> 95%). Remaining OTUs with very low abundance were typical soil bacterial taxa indicating their environmental origin.ConclusionsNo correlation was found between the CFU abundance and the relative abundance from the culture-independent approach. This suggests that many culturable taxa detected by HTS but not by culture-dependent method were not viable or were not in their culturable state. Overall, our HTS results show that the midgut bacterial community of A. americanum is very poor without a core microbiome and the majority of bacteria are endosymbiotic.
| S-EPMC7807426 | biostudies-literature
Project description:Viruses in the family Bunyaviridae infect a wide range of plant, insect, and animal hosts. Tick-borne bunyaviruses in the Phlebovirus genus, including Severe Fever with Thrombocytopenia Syndrome virus (SFTSV) in China, Heartland virus (HRTV) in the United States, and Bhanja virus in Eurasia and Africa have been associated with acute febrile illness in humans. Here we sought to characterize the growth characteristics and genome of Lone Star virus (LSV), an unclassified bunyavirus originally isolated from the lone star tick Amblyomma americanum. LSV was able to infect both human (HeLa) and monkey (Vero) cells. Cytopathic effects were seen within 72 h in both cell lines; vacuolization was observed in infected Vero, but not HeLa, cells. Viral culture supernatants were examined by unbiased deep sequencing and analysis using an in-house developed rapid computational pipeline for viral discovery, which definitively identified LSV as a phlebovirus. De novo assembly of the full genome revealed that LSV is highly divergent, sharing <61% overall amino acid identity with any other bunyavirus. Despite this sequence diversity, LSV was found by phylogenetic analysis to be part of a well-supported clade that includes members of the Bhanja group viruses, which are most closely related to SFSTV/HRTV. The genome sequencing of LSV is a critical first step in developing diagnostic tools to determine the risk of arbovirus transmission by A. americanum, a tick of growing importance given its expanding geographic range and competence as a disease vector. This study also underscores the power of deep sequencing analysis in rapidly identifying and sequencing the genomes of viruses of potential clinical and public health significance.
| S-EPMC3639253 | biostudies-literature
Project description:Multiple tick saliva proteins, the majority of which are unknown, confer tick resistance in repeatedly infested animals. The objective of this study was to identify the 24-48 h fed Amblyomma americanum tick saliva immuno-proteome. The 24-48 h tick-feeding phase is critical to tick parasitism as it precedes important events in tick biology, blood meal feeding and disease agent transmission. Fed male, 24 and 96 h fed female phage display cDNA expression libraries were biopanned using rabbit antibodies to 24 and 48 h fed A. americanum female tick saliva proteins. Biopanned immuno-cDNA libraries were subjected to next generation sequencing, de novo assembly, and bioinformatic analysis.More than 800 transcripts that code for 24-48 h fed A. americanum immuno-proteins are described. Of the 895 immuno-proteins, 52% (464/895) were provisionally identified based on matches in GenBank. Of these, ~19% (86/464) show high level of identity to other tick hypothetical proteins, and the rest include putative proteases (serine, cysteine, leukotriene A-4 hydrolase, carboxypeptidases, and metalloproteases), protease inhibitors (serine and cysteine protease inhibitors, tick carboxypeptidase inhibitor), and transporters and/or ligand binding proteins (histamine binding/lipocalin, fatty acid binding, calreticulin, hemelipoprotein, IgG binding protein, ferritin, insulin-like growth factor binding proteins, and evasin). Others include enzymes (glutathione transferase, cytochrome oxidase, protein disulfide isomerase), ribosomal proteins, and those of miscellaneous functions (histamine release factor, selenoproteins, tetraspanin, defensin, heat shock proteins).Data here demonstrate that A. americanum secretes a complex cocktail of immunogenic tick saliva proteins during the first 24-48 h of feeding. Of significance, previously validated immunogenic tick saliva proteins including AV422 protein, calreticulin, histamine release factor, histamine binding/lipocalins, selenoproteins, and paramyosin were identified in this screen, supporting the specificity of the approach in this study. While descriptive, this study opens opportunities for in-depth tick feeding physiology studies.
| S-EPMC4099483 | biostudies-literature
Project description:Amblyomma americanum ticks transmit more than a third of human tick-borne disease (TBD) agents in the United States. Tick saliva proteins are critical to success of ticks as vectors of TBD agents, and thus might serve as targets in tick antigen-based vaccines to prevent TBD infections. We describe a systems biology approach to identify, by LC-MS/MS, saliva proteins (tick = 1182, rabbit = 335) that A. americanum ticks likely inject into the host every 24 h during the first 8 days of feeding, and towards the end of feeding. Searching against entries in GenBank grouped tick and rabbit proteins into 27 and 25 functional categories. Aside from housekeeping-like proteins, majority of tick saliva proteins belong to the tick-specific (no homology to non-tick organisms: 32%), protease inhibitors (13%), proteases (8%), glycine-rich proteins (6%) and lipocalins (4%) categories. Global secretion dynamics analysis suggests that majority (74%) of proteins in this study are associated with regulating initial tick feeding functions and transmission of pathogens as they are secreted within 24-48 h of tick attachment. Comparative analysis of the A. americanum tick saliva proteome to five other tick saliva proteomes identified 284 conserved tick saliva proteins: we speculate that these regulate critical tick feeding functions and might serve as tick vaccine antigens. We discuss our findings in the context of understanding A. americanum tick feeding physiology as a means through which we can find effective targets for a vaccine against tick feeding.
| S-EPMC7041860 | biostudies-literature
Project description:We previously identified a cross-tick species conserved tick feeding stimuli responsive Amblyomma americanum (Aam) AV422 gene. This study demonstrates that AamAV422 belongs to a novel group of arthropod proteins that is characterized by 14 cysteine amino acid residues: C(23)-X7/9-C(33)-X23/24-C(58)-X8-C(67)-X7-C(75)-X23-C(99)-X15-C(115)-X10-C(126)-X24/25/33-C(150)C(151)-X7-C(159)-X8-C(168)-X23/24-C(192)-X9/10-C(202) predicted to form seven disulfide bonds. We show that AamAV422 protein is a ubiquitously expressed protein that is injected into the host within the first 24h of the tick attaching onto the host as revealed by Western blotting analyses of recombinant (r)AamAV422, tick saliva and dissected tick organ protein extracts using antibodies to 24 and 48 h tick saliva proteins. Native AamAV422 is apparently involved with mediating tick anti-hemostasis and anti-complement functions in that rAamAV422 delayed plasma clotting time in a dose responsive manner by up to ≈ 160 s, prevented platelet aggregation by up to ≈ 16% and caused ≈ 24% reduction in production of terminal complement complexes. Target validation analysis revealed that rAamAV422 is a potential candidate for a cocktail or multivalent tick vaccine preparation in that RNA interference (RNAi)-mediated silencing of AamAV422 mRNA caused a statistically significant (≈ 44%) reduction in tick engorgement weights, which is proxy for amounts of ingested blood. We speculate that AamAV422 is a potential target antigen for development of the highly desired universal tick vaccine in that consistent with high conservation among ticks, antibodies to 24h Ixodes scapularis tick saliva proteins specifically bound rAamAV422. We discuss data in this study in the context of advancing the biology of tick feeding physiology and discovery of potential target antigens for tick vaccine development.
| S-EPMC4058329 | biostudies-literature
Project description:BACKGROUND:The geographic range of the tick Amblyomma americanum, a vector of diseases of public health significance such as ehrlichiosis, has expanded from the southeast of the United States northward during the 20th century. Recently, populations of this tick have been reported to be present close to the Canadian border in Michigan and New York states, but established populations are not known in Canada. Previous research suggests that changing temperature patterns with climate change may influence tick life cycles and permit northward range expansion of ticks in the northern hemisphere. OBJECTIVES:We aimed to estimate minimal temperature conditions for survival of A. americanum populations at the northern edge of the tick's range and to investigate the possibility of range expansion of A. americanum into northern U.S. states and southern Canada in the coming decades. METHODS:A simulation model of the tick A. americanum was used, via simulations using climate data from meteorological stations in the United States and Canada, to estimate minimal temperature conditions for survival of A. americanum populations at the northern edge of the tick's range. RESULTS:The predicted geographic scope of temperature suitability [≥3,285 annual cumulative degree days (DD) >0°C] included most of the central and eastern U.S. states east of longitude 110°W, which is consistent with current surveillance data for the presence of the tick in this region, as well as parts of southern Quebec and Ontario in Canada. Regional climate model output raises the possibility of northward range expansion into all provinces of Canada from Alberta to Newfoundland and Labrador during the coming decades, with the greatest northward range expansion (up to 1,000km by the year 2100) occurring under the greenhouse gas (GHG) emissions of Representative Concentration Pathway (RCP) 8.5. Predicted northward range expansion was reduced by approximately half under the reduced GHG emissions of RCP4.5. DISCUSSION:Our results raise the possibility of range expansion of A. americanum into northern U.S. states and southern Canada in the coming decades, and conclude that surveillance for this tick, and the diseases it transmits, would be prudent. https://doi.org/10.1289/EHP5668.
| S-EPMC6867274 | biostudies-literature
Project description:The adaptation of hard ticks to feed for long periods is facilitated by the cement cone, which securely anchors the tick mouthparts onto host skin and protects the tick from being groomed off by the host. Thus, preventing tick cement deposition is an attractive target for the development of innovative tick control. We used LC-MS/MS sequencing to identify 160 Amblyomma americanum tick cement proteins that include glycine-rich proteins (GRP, 19%), protease inhibitors (12%), proteins of unknown function (11%), mucin (4%), detoxification, storage, and lipocalin at 1% each, and housekeeping proteins (50%). Spatiotemporal transcription analysis showing mRNA expression in multiple tick organs and transcript abundance increasing with feeding suggest that selected GRPs (n = 13) regulate multiple tick feeding functions, being classified as constitutively expressed (CE), feeding induced (FI), and up-regulated with feeding (UR). We show that transcription of CE GRPs is likely under the control of tick appetence associated factors in that mRNA abundance increased several thousand fold in 1 week old adult ticks, the time period that coincides with tick attainment of appetence. Given the high number of targets, we synthesized and injected unfed ticks with combinatorial (co) double stranded (ds)RNA and disrupted GRP mRNA in clusters according to similar transcription patterns: CE (n = 3), FI, (n = 4), and UR (n = 6) to streamline the work. Our data suggest that CE and FI GRPs are important for maintenance of the tick feeding site in that reddening and subsequent bleeding were observed around the mouthparts of CE and FI GRP co-dsRNA injected ticks during feeding. Furthermore, although not significantly different, indices for blood meal size and fecundity were apparently reduced in FI and UR ticks. We discuss our data with reference to A. americanum tick feeding physiology.
| S-EPMC5844823 | biostudies-literature