A story of a lone star tick: an imported case of Amblyomma americanum (Linnaeus, 1758) infected with Rickettsia amblyommatis that parasitized a US traveler returning to Mexico.
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SUBMITTER: Volkow P
PROVIDER: S-EPMC10243523 | biostudies-literature | 2023
REPOSITORIES: biostudies-literature
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A story of a lone star tick: an imported case of Amblyomma americanum (Linnaeus, 1758) infected with Rickettsia amblyommatis that parasitized a US traveler returning to Mexico.
Volkow Patricia P Grostieta Estefania E Salceda-Sánchez Beatriz B Huerta-Jiménez Herón H Alcántara-Rodríguez Virginia V Becker Ingeborg I Sánchez-Montes Sokani S
Revista do Instituto de Medicina Tropical de Sao Paulo 20230601
In this study, we report the presence of a female Amblyomma americanum tick attached to a former resident of the East Coast of the United States who moved to Mexico city. The amplification and sequencing of gene fragments of the 16S-rDNA and cytochrome c oxidase subunit 1 corroborated the identification of the species of the tick. Additionally, the presence of DNA of Rickettsia amblyommatis was confirmed. This work is the first report of an exotic tick of the genus Amblyomma in a traveler from t ...[more]
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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:A collection of 1145 clones from an EST project on female tick salivary gland genes was hybridized on glass slides to RNA extracted from several feeding stages of adult female tick salivary glands, including unfed and replete, and from adult male ticks, either unfed or fed in the presence or absence of female ticks. In the female ticks, the early fed (<50 mg) and partially fed (30-200 mg) groups were very similar. The fast feeding (350-500 mg) and replete ticks were similar to each other, but different from the partially fed. The unfed ticks were more similar to the fast feeding – replete groups than the early fed-partially fed groups. In the males, there were differences between the males fed in the presence or absence of females, but overall, these groups were very similar. The unfed ticks were significantly different from the fed ticks. Males showed clear differences with females in expression, as well. The unfed females had high levels of genes involved in protein synthesis, while genes possibly involved in survival on the host, such as anticoagulants, seemed to be most expressed in the early and partially fed states. By contrast, in the males, the protein synthesis genes were expressed more in all three groups, while the putative secreted genes for survival were expressed less. Keywords: time course, effect of feeding, sex, effect of presence of females
2006-06-08 | GSE5010 | GEO
Project description:The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson's Diversity indices ranging from 1.28-89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05), collection site (P < 0.05), and sex (P < 0.1) suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra-species differences in microbiomes were not due solely to pathogen presence/absence, but may be also driven by vector life history factors, including environment, life stage, population structure, and host choice.
| S-EPMC4709196 | biostudies-literature
Project description:Ticks are important vectors for many emerging pathogens. However, they are also infected with many symbionts and commensals, often competing for the same niches. In this paper, we characterize the microbiome of Amblyomma americanum (Acari: Ixodidae), the lone star tick, in order to better understand the evolutionary relationships between pathogens and nonpathogens. Multitag pyrosequencing of prokaryotic 16S rRNA genes (16S rRNA) was performed on 20 lone star ticks (including males, females, and nymphs). Pyrosequencing of the rickettsial sca0 gene (also known as ompA or rompA) was performed on six ticks. Female ticks had less diverse microbiomes than males and nymphs, with greater population densities of Rickettsiales. The most common members of Rickettsiales were "Candidatus Rickettsia amblyommii" and "Candidatus Midichloria mitochondrii." "Ca. Rickettsia amblyommii" was 2.6-fold more common in females than males, and there was no sequence diversity in the sca0 gene. These results are consistent with a predominantly vertical transmission pattern for "Ca. Rickettsia amblyommii."
| S-EPMC3910995 | biostudies-literature
Project description:A collection of 1145 clones from an EST project on female tick salivary gland genes was hybridized on glass slides to RNA extracted from several feeding stages of adult female tick salivary glands, including unfed and replete, and from adult male ticks, either unfed or fed in the presence or absence of female ticks. In the female ticks, the early fed (<50 mg) and partially fed (30-200 mg) groups were very similar. The fast feeding (350-500 mg) and replete ticks were similar to each other, but different from the partially fed. The unfed ticks were more similar to the fast feeding â replete groups than the early fed-partially fed groups. In the males, there were differences between the males fed in the presence or absence of females, but overall, these groups were very similar. The unfed ticks were significantly different from the fed ticks. Males showed clear differences with females in expression, as well. The unfed females had high levels of genes involved in protein synthesis, while genes possibly involved in survival on the host, such as anticoagulants, seemed to be most expressed in the early and partially fed states. By contrast, in the males, the protein synthesis genes were expressed more in all three groups, while the putative secreted genes for survival were expressed less. Keywords: time course, effect of feeding, sex, effect of presence of females All samples were compared to the partially fed females. Females consisted of five groups: unfed, early fed, partially fed, fast feeding and replete. Four or five biological replicates were done of each, with the dyes used in both possible ways. In the males, three groups were used: unfed, feeding in the presence of females, and feeding in the absence of females. Two biological replicates were done of the feeding males, and one of extracts was hybridized twice for the males fed in the presence of females. Unfed males used one RNA sample, extracted from a large pool of ticks.
2010-06-11 | E-GEOD-5010 | biostudies-arrayexpress
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:BackgroundRickettsia amblyommii is a bacterium in the spotted fever group of organisms associated with the lone star tick (LST), Amblyomma americanum. The LST is the most commonly reported tick to parasitize humans in the southeastern US. Within this geographic region, there have been suspected cases of Rocky Mountain spotted fever (RMSF) where the causative agent, R. rickettsii, was not identified in the local tick population. In these areas, patients with clinical signs of RMSF had low or no detectable antibodies to R. rickettsii, resulting in an inability to confirm a diagnosis.MethodsR. amblyommii was cultivated from host-seeking LSTs trapped in Central Florida and propagated in ISE6 (Ixodes scapularis) and AAE2 (A. americanum) cells. Quantitative PCR targeting the 17-kD gene of Rickettsia spp. identified the genus of the organism in culture. Variable regions of groEL, gtlA and rompA genes were amplified and sequenced to confirm the species. The prevalence of R. amblyommii in LSTs within the geographic region was determined by qPCR followed by conventional PCR and direct sequencing.ResultsAnalyses of amplified sequences from the cultured organism were 100% homologous to R. amblyommii. The overall prevalence of Rickettsia spp. in the local population of LSTs was 57.1% and rompA sequence analysis identified only R. amblyommii in LSTs.ConclusionsA Florida strain of R. amblyommii was successfully cultivated in two tick cell lines. Further evaluation of the new strain and comparisons to the other geographic strains is needed. The prevalence of this SFG organism in the tick population warrants further investigation into the organism's ability to cause clinical disease in mammalian species.
| S-EPMC4077227 | biostudies-literature
Project description:Hematophagous arthropods can acquire and transmit several pathogens of medical importance. In ticks, the innate immune system is crucial in the outcome between vector-pathogen interaction and overall vector competence. However, the specific immune response(s) elicited by the immune cells known as hemocytes remains largely undefined in Ehrlichia chaffeensis and its competent tick vector, Amblyomma americanum. Here, we show that granulocytes, professional phagocytic cells, are integral in eliciting immune responses against commensal and pathogen infection. The chemical depletion of granulocytes led to decreased phagocytic efficiency of tissues-associated hemocytes. We demonstrate E. chaffeensis can infect circulating hemocytes, and both cell-free plasma and hemocytes from E. chaffeensis-infected ticks can establish Ehrlichia infection in recipient ticks. Lastly, we provide evidence to show granulocytes play a dual role in E. chaffeensis infection. Depleting granulocytic hemocytes increased Ehrlichia load in the salivary gland and midgut tissues. In contrast, granulocyte depletion led to a reduced systemic load of Ehrlichia. This study has identified multiple roles for granulocytic hemocytes in the control and systemic dissemination of E. chaffeensis infection.
| S-EPMC10794049 | biostudies-literature
Project description:Ixodid ticks are ectoparasites that feed exclusively on blood as their source of nutrients. Although ticks spend most of their life off the host, until now it has been assumed that the blood and the water vapor are the only sources of water to maintain water balance and prevent desiccation. Here we report for the first time that adult lone star ticks, Amblyomma americanum, also actively drink nutrient-free water, which greatly increases their survival. The volume of ingested water is greater in females than males (0.55 ± 0.06 vs 0.44 ± 0.07 µl) and most likely due to differences in tick size. Water uptake occurs through mouthparts and it can be later observed in the salivary glands and the midgut. We also exploited this behavior by adding a variety of inorganic compounds and microorganisms to water. Addition of inorganic salts to drinking water such as KH2PO4 + NaCl+KNO3 resulted in 100% tick mortality within 3 days. As a proof of concept for using the water drinking as a delivery route of toxic reagents for ticks, we also show that adding Pseudomonas aeruginosa to drinking water quickly leads to tick death. This tick behavior can be exploited to target important physiological systems, which would make ticks vulnerable to dehydration and microbial dysbiosis.
| S-EPMC7138852 | biostudies-literature
Project description:The lone star tick (Amblyomma americanum) is an abundant and aggressive biter of humans, domestic animals, and wildlife in the southeastern-central USA and an important vector of several known and suspected zoonotic bacterial pathogens. However, the biological drivers of bacterial community variation in this tick are still poorly defined. Knowing the community context in which tick-borne bacterial pathogens exist and evolve is required to fully understand the ecology and immunobiology of the ticks and to design effective public health and veterinary interventions. We performed a metagenomic survey of the bacterial communities of questing A. americanum and tested 131 individuals (66 nymphs, 24 males, and 41 females) from five sites in three states. Pyrosequencing was performed with barcoded eubacterial primers targeting variable 16S rRNA gene regions 5-3. The bacterial communities were dominated by Rickettsia (likely R. amblyommii) and an obligate Coxiella symbiont, together accounting for 6.7-100% of sequences per tick. DNAs from Midichloria, Borrelia, Wolbachia, Ehrlichia, Pseudomonas, or unidentified Bacillales, Enterobacteriaceae, or Rhizobiales groups were also detected frequently. Wolbachia and Midichloria significantly co-occurred in Georgia (p<0.00001), but not in other states. The significance of the Midichloria-Wolbachia co-occurrence is unknown. Among ticks collected in Georgia, nymphs differed from adults in both the composition (p = 0.002) and structure (p = 0.002) of their bacterial communities. Adults differed only in their community structure (p = 0.002) with males containing more Rickettsia and females containing more Coxiella. Comparisons among adult ticks collected in New York and North Carolina supported the findings from the Georgia collection despite differences in geography, collection date, and sample handling, implying that the differences detected are consistent attributes. The data also suggest that some members of the bacterial community change during the tick life cycle and that some sex-specific attributes may be detectable in nymphs.
| S-EPMC4108322 | biostudies-literature