Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| q fever: current state of knowledge and perspectives of research of a neglected zoonosis. | q fever is an ubiquitous zoonosis caused by an resistant intracellular bacterium, coxiella burnetii. in certain areas, q fever can be a severe public health problem, and awareness of the disease must be promoted worldwide. nevertheless, knowledge of coxiella burnetii remains limited to this day. its resistant (intracellular and environmental) and infectious properties have been poorly investigated. further understanding of the interactions between the infected host and the bacteria is necessary. ... | 2011 | 22194752 |
| a deep insight into the sialotranscriptome of the gulf coast tick, amblyomma maculatum. | saliva of blood sucking arthropods contains compounds that antagonize their hosts' hemostasis, which include platelet aggregation, vasoconstriction and blood clotting; saliva of these organisms also has anti-inflammatory and immunomodullatory properties. perhaps because hosts mount an active immune response against these compounds, the diversity of these compounds is large even among related blood sucking species. because of these properties, saliva helps blood feeding as well as help the establ ... | 2011 | 22216098 |
| the role of nuclear technologies in the diagnosis and control of livestock diseases--a review. | nuclear and nuclear-related technologies have played an important role in animal health, particularly in relation to disease diagnosis and characterization of pathogenic organisms. this review focuses primarily on how and where nuclear technologies, both non-isotopic and isotopic methods, have made their impact in the past and where it might be expected they could have an impact in the future. the review outlines the extensive use of radiation attenuation in attempts to create vaccines for a mul ... | 2012 | 22286376 |
| the sialotranscriptome of antricola delacruzi female ticks is compatible with non-hematophagous behavior and an alternative source of food. | the hosts for antricola delacruzi ticks are insectivorous, cave-dwelling bats on which only larvae are found. the mouthparts of nymphal and adult a. delacruzi are compatible with scavenging feeding because the hypostome is small and toothless. how a single blood meal of a larva provides energy for several molts as well as for oviposition by females is not known. adults of a. delacruzi possibly feed upon an unknown food source in bat guano, a substrate on which nymphal and adult stages are always ... | 2012 | 22306723 |
| phylogenetic analysis of myobia musculi (schranck, 1781) by using the 18s small ribosomal subunit sequence. | we used high-fidelity pcr to amplify 2 overlapping regions of the ribosomal gene complex from the rodent fur mite myobia musculi. the amplicons encompassed a large portion of the mite's ribosomal gene complex spanning 3128 nucleotides containing the entire 18s rrna, internal transcribed spacer (its) 1,5.8s rrna, its2, and a portion of the 5'-end of the 28s rrna. m. musculi's 179-nucleotide 5.8s rrna nucleotide sequence was not conserved, so this region was identified by conservation of rrna seco ... | 0 | 22330574 |
| immunoregulation of bovine macrophages by factors in the salivary glands of rhipicephalus microplus. | alternative strategies are required to control the southern cattle tick, rhipicephalus microplus, due to evolving resistance to commercially available acaricides. this invasive ectoparasite is a vector of economically important diseases of cattle such as bovine babesiosis and anaplasmosis. an understanding of the biological intricacies underlying vector-host-pathogen interactions is required to innovate sustainable tick management strategies that can ultimately mitigate the impact of animal and ... | 2012 | 22333193 |
| composition and seasonal variation of rhipicephalus turanicus and rhipicephalus sanguineus bacterial communities. | a 16s rrna gene approach, including 454 pyrosequencing and quantitative pcr (qpcr), was used to describe the bacterial community in rhipicephalus turanicus and to evaluate the dynamics of key bacterial tenants of adult ticks during the active questing season. the bacterial community structure of rh. turanicus was characterized by high dominance of coxiella and rickettsia and extremely low taxonomic diversity. parallel diagnostic pcr further revealed a novel coxiella species which was present and ... | 2012 | 22467507 |
| dispersion and sampling of adult dermacentor andersoni in rangeland in western north america. | a fixed precision sampling plan was developed for off-host populations of adult rocky mountain wood tick, dermacentor andersoni (stiles) based on data collected by dragging at 13 locations in alberta, canada; washington; and oregon. in total, 222 site-date combinations were sampled. each site-date combination was considered a sample, and each sample ranged in size from 86 to 250 10 m2 quadrats. analysis of simulated quadrats ranging in size from 10 to 50 m2 indicated that the most precise sample ... | 2012 | 22493841 |
| molecular cloning and sequence analysis of the cdnas encoding toxin-like peptides from the venom glands of tarantula grammostola rosea. | tarantula venom glands produce a large variety of bioactive peptides. here we present the identification of venom components obtained by sequencing clones isolated from a cdna library prepared from the venom glands of the chilean common tarantula, grammostola rosea. the cdna sequences of about 1500 clones out of 4000 clones were analyzed after selection using several criteria. forty-eight novel toxin-like peptides (gtx1 to gtx7, and gtx-tctp and gtx-crisp) were predicted from the nucleotide sequ ... | 2012 | 22500178 |
| expression patterns of anaplasma marginale msp2 variants change in response to growth in cattle, and tick cells versus mammalian cells. | antigenic variation of major surface proteins is considered an immune-evasive maneuver used by pathogens as divergent as bacteria and protozoa. likewise, major surface protein 2 (msp2) of the tick-borne pathogen, anaplasma marginale, is thought to be involved in antigenic variation to evade the mammalian host immune response. however, this dynamic process also works in the tick vector in the absence of immune selection pressure. we examined msp2 variants expressed during infection of four tick a ... | 2012 | 22558307 |
| tick salivary secretion as a source of antihemostatics. | ticks are mostly obligatory blood feeding ectoparasites that have an impact on human and animal health. in addition to direct damage due to feeding, some tick species serve as the vectors for the causative agents of several diseases, such as the spirochetes of the genus borrelia causing lyme disease, the virus of tick-borne encephalitis, various rickettsial pathogens or even protozoan parasites like babesia spp. hard ticks are unique among bloodfeeders because of their prolonged feeding period t ... | 2012 | 22564820 |
| expansion of variant diversity associated with a high prevalence of pathogen strain superinfection under conditions of natural transmission. | superinfection occurs when a second, genetically distinct pathogen strain infects a host that has already mounted an immune response to a primary strain. for antigenically variant pathogens, the primary strain itself expresses a broad diversity of variants over time. thus, successful superinfection would require that the secondary strain express a unique set of variants. we tested this hypothesis under conditions of natural transmission in both temperate and tropical regions where, respectively, ... | 2012 | 22585962 |
| parasite diversity and coinfection determine pathogen infection success and host fitness. | while the importance of changes in host biodiversity for disease risk continues to gain empirical support, the influence of natural variation in parasite diversity on epidemiological outcomes remains largely overlooked. here, we combined field infection data from 2,191 amphibian hosts representing 158 parasite assemblages with mechanistic experiments to evaluate the influence of parasite richness on both parasite transmission and host fitness. using a guild of larval trematode parasites (six spe ... | 2012 | 22615371 |
| transovarial transmission of rickettsia spp. and organ-specific infection of the whitefly bemisia tabaci. | the whitefly bemisia tabaci is a cosmopolitan insect pest that harbors portiera aleyrodidarum, the primary obligatory symbiotic bacterium, and several facultative secondary symbionts. secondary symbionts in b. tabaci are generally associated with the bacteriome, ensuring their vertical transmission; however, rickettsia is an exception and occupies most of the body cavity, except the bacteriome. the mode of rickettsia transfer between generations and its subcellular localization in insect organs ... | 2012 | 22660706 |
| co2 flagging - an improved method for the collection of questing ticks. | most epidemiological studies on tick-borne pathogens involve collection of ticks from the environment. an efficient collection method is essential for large sample pools. our main aim was to evaluate the efficacy of a new method, where traditional flagging was enhanced by the use of co2 dispersed into the white flannel. the co2 was spread through a rubber hose network inserted into the flag blanket. the research was conducted in spring, in march-april 2011 in two locations from cluj county, roma ... | 2012 | 22720872 |
| why are there so few rickettsia conorii conorii-infected rhipicephalus sanguineus ticks in the wild? | rickettsia conorii conorii is the etiological agent of mediterranean spotted fever, which is transmitted by the brown dog tick, rhipicephalus sanguineus. the relationship between the rickettsia and its tick vector are still poorly understood one century after the first description of this disease. | 2012 | 22724035 |
| tropism and pathogenicity of rickettsiae. | rickettsiae are obligate intracellular parasitic bacteria that cause febrile exanthematous illnesses such as rocky mountain spotted fever, mediterranean spotted fever, epidemic, and murine typhus, etc. although the vector ranges of each rickettsia species are rather restricted; i.e., ticks belonging to arachnida and lice and fleas belonging to insecta usually act as vectors for spotted fever group (sfg) and typhus group (tg) rickettsiae, respectively, it would be interesting to elucidate the mec ... | 2012 | 22737150 |
| detection and identification of putative bacterial endosymbionts and endogenous viruses in tick cell lines. | as well as being vectors of many viral, bacterial, and protozoan pathogens of medical and veterinary importance, ticks harbour a variety of microorganisms which are not known to be pathogenic for vertebrate hosts. continuous cell lines established from ixodid and argasid ticks could be infected with such endosymbiotic bacteria and endogenous viruses, but to date very few cell lines have been examined for their presence. dna and rna extracted from over 50 tick cell lines deposited in the roslin w ... | 2012 | 22743047 |
| identification of endosymbionts in ticks by broad-range polymerase chain reaction and electrospray ionization mass spectrometry. | many organisms, such as insects, filarial nematodes, and ticks, contain heritable bacterial endosymbionts that are often closely related to transmissible tickborne pathogens. these intracellular bacteria are sometimes unique to the host species, presumably due to isolation and genetic drift. we used a polymerase chain reaction/electrospray ionization-mass spectrometry assay designed to detect a wide range of vectorborne microorganisms to characterize endosymbiont genetic signatures from amblyomm ... | 2012 | 22897044 |
| unusual bacterial infections and the pleura. | rickettsiosis, q fever, tularemia, and anthrax are all bacterial diseases that can affect the pleura. rocky mountain spotted fever (rmsf) and mediterranean spotted fever (msf) are caused by rickettsia rickettsii and rickettsia conorii, respectively. pleural fluid from a patient with msf had a neutrophil-predominant exudate. coxiellaburnetii is the causative agent of q fever. of the two cases described in the literature, one was an exudate with a marked eosinophilia while the other case was a tra ... | 2012 | 22977649 |
| subdominant antigens in bacterial vaccines: am779 is subdominant in the anaplasma marginale outer membrane vaccine but does not associate with protective immunity. | identification of specific antigens responsible for the ability of complex immunogens to induce protection is a major goal in development of bacterial vaccines. much of the investigation has focused on highly abundant and highly immunodominant outer membrane proteins. recently however, genomic and proteomic approaches have facilitated identification of minor components of the bacterial outer membrane that have previously been missed or ignored in immunological analyses. immunization with anaplas ... | 2012 | 23029498 |
| ixodes scapularis saliva mitigates inflammatory cytokine secretion during anaplasma phagocytophilum stimulation of immune cells. | ixodes scapularis saliva enables the transmission of infectious agents to the mammalian host due to its immunomodulatory, anesthetic and anti-coagulant properties. however, how i. scapularis saliva influences host cytokine secretion in the presence of the obligate intracellular rickettsial pathogen anaplasma phagocytophilum remains elusive. | 2012 | 23050849 |
| tick-box for 3'-end formation of mitochondrial transcripts in ixodida, basal chelicerates and drosophila. | according to the trna punctuation model, the mitochondrial genome (mtdna) of mammals and arthropods is transcribed as large polycistronic precursors that are maturated by endonucleolytic cleavage at trna borders and rna polyadenylation. starting from the newly sequenced mtdna of ixodes ricinus and using a combination of mitogenomics and transcriptional analyses, we found that in all currently-sequenced tick lineages (prostriata, metastriata and argasidae) the 3'-end of the polyadenylated nad1 an ... | 2012 | 23077630 |
| powassan virus infection: case series and literature review from a single institution. | powassan virus is a flavivirus related to eastern hemisphere's tick-borne encephalitis viruses. it can cause a rare but potentially life-threatening disease including encephalitis. | 2012 | 23111001 |
| comparative genomics and transcriptomics of trait-gene association. | the order rickettsiales includes important tick-borne pathogens, from rickettsia rickettsii, which causes rocky mountain spotted fever, to anaplasma marginale, the most prevalent vector-borne pathogen of cattle. although most pathogens in this order are transmitted by arthropod vectors, little is known about the microbial determinants of transmission. a. marginale provides unique tools for studying the determinants of transmission, with multiple strain sequences available that display distinct a ... | 2012 | 23181781 |
| hitch-hiker taken for a ride: an unusual cause of myocarditis, septic shock and adult respiratory distress syndrome. | rocky mountain spotted fever (rmsf) is a serious tick-borne illness caused by rickettsia rickettsii that is endemic in southeastern usa. although rmsf has been described as causing the classic clinical triad of fever, headache and a characteristic rash, serious and potentially life-threatening manifestations can occur. cardiopulmonary involvement, although infrequent, may occur with severe cases of rmsf. rickettsial myocarditis is an uncommon occurrence. we present a case of a previously healthy ... | 2013 | 23314875 |
| intertwined arbovirus transmission activity: reassessing the transmission cycle paradigm. | arboviruses are emerging/reemerging infectious agents worldwide. the factors within this scenario include vector and host population fluctuations, climatic changes, anthropogenic activities that disturb ecosystems, an increase in international flights, human mobility, and genetic mutations that allow spill-over phenomenon. arboviruses are maintained by biologic transmission among vectors and hosts. sometimes this biological transmission is specific and includes one vector and host species such a ... | 2013 | 23335900 |
| identification of multilocus genetic heterogeneity in anaplasma marginale subsp. centrale and its restriction following tick-borne transmission. | anaplasma marginale subsp. centrale was the first vaccine used to protect against a rickettsial disease and is still in widespread use a century later. as its use preceded development of either cryopreservation or cell culture, the vaccine strain was maintained for decades by sequential passage among donor animals, excluding the natural tick-borne transmission cycle that provides a selective pressure or population "bottleneck." we demonstrated that the vaccine strain is genetically heterogeneous ... | 2013 | 23509140 |
| hybridization in natural sympatric populations of dermacentor ticks in northwestern north america. | hybridization in ticks has been described in a handful of species and mostly as a result of laboratory experiments. we used 148 aflp loci to describe putative hybridization events between d. andersoni and d. variabilis in sympatric populations from northwestern north america. recently, d. variabilis has expanded its range westward into the natural range of d. andersoni. using a sample of 235 d. andersoni and 62 d. variabilis, we identified 31 individuals as putative hybrids: four f2 individuals ... | 2013 | 23531531 |
| what is the risk for exposure to vector-borne pathogens in united states national parks? | united states national parks attract > 275 million visitors annually and collectively present risk of exposure for staff and visitors to a wide range of arthropod vector species (most notably fleas, mosquitoes, and ticks) and their associated bacterial, protozoan, or viral pathogens. we assessed the current state of knowledge for risk of exposure to vector-borne pathogens in national parks through a review of relevant literature, including internal national park service documents and organismal ... | 2013 | 23540107 |
| effects of bartonella spp. on flea feeding and reproductive performance. | numerous pathogens are transmitted from one host to another by hematophagous insect vectors. the interactions between a vector-borne organism and its vector vary in many ways, most of which are yet to be explored and identified. these interactions may play a role in the dynamics of the infection cycle. one way to evaluate these interactions is by studying the effects of the tested organism on the vector. in this study, we tested the effects of infection with bartonella species on fitness-related ... | 2013 | 23542614 |
| protective immunity induced by immunization with a live, cultured anaplasma marginale strain. | despite significant economic losses resulting from infection with anaplasma marginale, a tick-transmitted rickettsial pathogen of cattle, available vaccines provide, at best, only partial protection against clinical disease. the green-fluorescent protein expressing mutant of the a. marginale st. maries strain is a live, marked vaccine candidate (amstm-gfp). to test whether amstm-gfp is safe and provides clinical protection, a group of calves was vaccinated, and clinical parameters, including per ... | 2013 | 23664994 |
| range expansion of dermacentor variabilis and dermacentor andersoni (acari: ixodidae) near their northern distributional limits. | distributional ranges of the ticks dermacentor andersoni stiles and dermacentor variabilis (say) in the canadian prairies were determined by passive surveillance and active collection. these findings were compared with historical records of both species, particularly in the province of saskatchewan, where the northern distributional limits of both tick species occur. before the 1960s, d. variabilis and d. andersoni were allopatric in saskatchewan; however, since then, the distribution of d. vari ... | 2013 | 23802445 |
| novel immunomodulators from hard ticks selectively reprogramme human dendritic cell responses. | hard ticks subvert the immune responses of their vertebrate hosts in order to feed for much longer periods than other blood-feeding ectoparasites; this may be one reason why they transmit perhaps the greatest diversity of pathogens of any arthropod vector. tick-induced immunomodulation is mediated by salivary components, some of which neutralise elements of innate immunity or inhibit the development of adaptive immunity. as dendritic cells (dc) trigger and help to regulate adaptive immunity, the ... | 2013 | 23825947 |
| endogenous tick viruses and modulation of tick-borne pathogen growth. | ticks transmit a wide range of viral, bacterial and protozoan pathogens, many of which can establish persistent infections of lifelong duration in the vector tick and in some cases are transmitted transovarially to the next generation. in addition many ixodid and argasid tick cell lines and, by inference the parent ticks from which they were derived, harbor endogenous viruses (etv) of which almost nothing is known. in general, low level persistent infections with viral pathogens (arboviruses) ar ... | 2013 | 23875176 |
| interaction of the tick immune system with transmitted pathogens. | ticks are hematophagous arachnids transmitting a wide variety of pathogens including viruses, bacteria, and protozoans to their vertebrate hosts. the tick vector competence has to be intimately linked to the ability of transmitted pathogens to evade tick defense mechanisms encountered on their route through the tick body comprising midgut, hemolymph, salivary glands or ovaries. tick innate immunity is, like in other invertebrates, based on an orchestrated action of humoral and cellular immune re ... | 2013 | 23875177 |
| characterization of haemaphysalis flava (acari: ixodidae) from qingling subspecies of giant panda (ailuropoda melanoleuca qinlingensis) in qinling mountains (central china) by morphology and molecular markers. | tick is one of important ectoparasites capable of causing direct damage to their hosts and also acts as vectors of relevant infectious agents. in the present study, the taxa of 10 ticks, collected from qinling giant pandas (ailuropoda melanoleuca qinlingensis) in qinling mountains of china in april 2010, were determined using morphology and molecular markers (nucleotide its2 rdna and mitochondrial 16s). microscopic observation demonstrated that the morphological features of these ticks were simi ... | 2013 | 23894541 |
| reinstatement of dermacentor kamshadalus neumann (acari: ixodidae) as a valid species parasitizing mountain goats and sheep in the united states, canada, and russia. | reexamination of dermacentor albipictus (packard, 1869) holdings stored in the united states national tick collection revealed several collections of a morphologically distinct dermacentor species. comparison of these specimens with other dermacentor taxa showed that they are identical to an old taxon originally described as dermacentor variegatus kamshadalus neumann, 1908. for more than a century, this taxon was known only from the male holotype specimen collected in russia, and the name was co ... | 0 | 23926766 |
| comparative evaluation of infected and noninfected amblyomma triste ticks with rickettsia parkeri, the agent of an emerging rickettsiosis in the new world. | the distribution of rickettsia parkeri in south america has been associated with amblyomma triste ticks. the present study evaluated under laboratory conditions two colonies of a. triste: one started from engorged females that were naturally infected by r. parkeri (designated as infected group); the other started from noninfected females (designated as control group). both colonies were reared in parallel for five consecutive generations. tick-naïve domestic rabbits were used for feeding of each ... | 2013 | 23936795 |
| de novo ixodes ricinus salivary gland transcriptome analysis using two next-generation sequencing methodologies. | tick salivary gland (sg) proteins possess powerful pharmacologic properties that facilitate tick feeding and pathogen transmission. for the first time, sg transcriptomes of ixodes ricinus, an important disease vector for humans and animals, were analyzed using next-generation sequencing. sgs were collected from different tick life stages fed on various animal species, including cofeeding of nymphs and adults on the same host. four cdna samples were sequenced, discriminating tick sg transcriptome ... | 2013 | 23964076 |
| tick salivary compounds: their role in modulation of host defences and pathogen transmission. | ticks require blood meal to complete development and reproduction. multifunctional tick salivary glands play a pivotal role in tick feeding and transmission of pathogens. tick salivary molecules injected into the host modulate host defence responses to the benefit of the feeding ticks. to colonize tick organs, tick-borne microorganisms must overcome several barriers, i.e., tick gut membrane, tick immunity, and moulting. tick-borne pathogens co-evolved with their vectors and hosts and developed m ... | 2013 | 23971008 |
| transmission of pathogens by stomoxys flies (diptera, muscidae): a review. | stomoxys flies are mechanical vectors of pathogens present in the blood and skin of their animal hosts, especially livestock, but occasionally humans. in livestock, their direct effects are disturbance, skin lesions, reduction of food intake, stress, blood loss, and a global immunosuppressive effect. they also induce the gathering of animals for mutual protection; meanwhile they favor development of pathogens in the hosts and their transmission. their indirect effect is the mechanical transmissi ... | 2013 | 23985165 |
| isolation of deer tick virus (powassan virus, lineage ii) from ixodes scapularis and detection of antibody in vertebrate hosts sampled in the hudson valley, new york state. | deer tick virus, dtv, is a genetically and ecologically distinct lineage of powassan virus (powv) also known as lineage ii powv. human incidence of pow encephalitis has increased in the last 15 years potentially due to the emergence of dtv, particularly in the hudson valley of new york state. we initiated an extensive sampling campaign to determine whether powv was extant throughout the hudson valley in tick vectors and/or vertebrate hosts. | 2013 | 24016533 |
| morphology of colonies of anaplasma marginale in nymphal dermacentor andersoni. | colonies of anaplasma marginale theiler were studied in midgut epithelial cells of nymphal dermacentor andersoni stiles that had become infected by feeding on splenectomized calves with anaplasmosis. colonies of a marginale were not observed in nymphal ticks killed during the 6-day feeding period, but were present in sections of midgut epithelial cells of ticks killed as early as 5 days after repletion. colonies of a marginale also were present in ticks examined throughout development to the adu ... | 1984 | 24049913 |
| asymptomatic petechial eruption on the lower legs. | the authors report an unusual case of rocky mountain spotted fever that presented as an asymptomatic petechial eruption on the lower legs. rocky mountain spotted fever is rare in new england and, as such, is typically not on the differential diagnosis when presented with such patients. what began as an asymptomatic eruption progressed to more classic signs of the disease, including a positive rocky mountain spotted fever titer. the patient was successfully treated with doxycydine and within a sh ... | 0 | 24062875 |
| mutation scanning-based identification of larval and nymphal ticks (acari: ixodidae) from richardson's ground squirrels (spermophilus richardsonii). | the objective of this study was to identify the tick species parasitizing richardson's ground squirrels (spermophilus richardsonii) in southern saskatchewan (canada). morphological examination of the adult ticks revealed the presence of three tick species, ixodes sculptus, ixodes kingi and dermacentor andersoni. however, given the difficulties in identifying some of the larval and nymphal (immature) ticks using this approach, pcr-based single-strand conformation polymorphism (sscp) and dna seque ... | 2014 | 24075866 |
| a novel rickettsia species detected in vole ticks (ixodes angustus) from western canada. | the genomic dna of ixodid ticks from western canada was tested by pcr for the presence of rickettsia. no rickettsiae were detected in ixodes sculptus, whereas 18% of the i. angustus and 42% of the dermacentor andersoni organisms examined were pcr positive for rickettsia. the rickettsiae from each tick species were characterized genetically using multiple genes. rickettsiae within the d. andersoni organisms had sequences at four genes that matched those of r. peacockii. in contrast, the rickettsi ... | 2013 | 24077705 |
| update on tick-borne rickettsioses around the world: a geographic approach. | tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus rickettsia. these zoonoses are among the oldest known vector-borne diseases. however, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. several species of tick-borne rickettsiae that wer ... | 0 | 24092850 |
| a nod to disease vectors: mitigation of pathogen sensing by arthropod saliva. | arthropod saliva possesses anti-hemostatic, anesthetic, and anti-inflammatory properties that facilitate feeding and, inadvertently, dissemination of pathogens. vector-borne diseases caused by these pathogens affect millions of people each year. many studies address the impact of arthropod salivary proteins on various immunological components. however, whether and how arthropod saliva counters nod-like (nlr) sensing remains elusive. nlrs are innate immune pattern recognition molecules involved i ... | 2013 | 24155744 |
| movement of male dermacentor andersoni (acari: ixodidae) among cattle. | movement of male dermacentor andersoni (stiles) was examined among 54 pairs of artificially infested donor and recipient cattle during a 3-yr period. the number of males declined at a rate independent of the initial level of infestation, while the rate of decline of females on the donor animals tended to increase with initial infestation level. male tick movement to recipient cattle was observed in 26 of 54 (48%) of the animal pairs, but varied among years and trials. movement tended to be great ... | 2013 | 24180101 |
| gene expression of tissue-specific molecules in ex vivo dermacentor variabilis (acari: ixodidae) during rickettsial exposure. | ticks serve as both vectors and the reservoir hosts capable of transmitting spotted fever group rickettsia by horizontal and vertical transmission. persistent maintenance of rickettsia species in tick populations is dependent on the specificity of the tick and rickettsia relationship that limits vertical transmission of particular rickettsia species, suggesting host-derived mechanisms of control. tick-derived molecules are differentially expressed in a tissue-specific manner in response to ricke ... | 0 | 24180114 |
| ticks and tick-borne pathogens at the cutaneous interface: host defenses, tick countermeasures, and a suitable environment for pathogen establishment. | ticks are unique among hematophagous arthropods by continuous attachment to host skin and blood feeding for days; complexity and diversity of biologically active molecules differentially expressed in saliva of tick species; their ability to modulate the host defenses of pain and itch, hemostasis, inflammation, innate and adaptive immunity, and wound healing; and, the diverse array of infectious agents they transmit. all of these interactions occur at the cutaneous interface in a complex sequence ... | 2013 | 24312085 |
| discovery of novel rickettsiella spp. in ixodid ticks from western canada. | the genomic dna from four species of ixodid ticks in western canada was tested for the presence of rickettsiella by pcr analyses targeting the 16s rrna gene. eighty-eight percent of the ixodes angustus (n = 270), 43% of the i. sculptus (n = 61), and 4% of the i. kingi (n = 93) individuals examined were pcr positive for rickettsiella, whereas there was no evidence for the presence of rickettsiella in dermacentor andersoni (n = 45). three different single-strand conformation polymorphism profiles ... | 2014 | 24334664 |
| laboratory identification of arthropod ectoparasites. | the collection, handling, identification, and reporting of ectoparasitic arthropods in clinical and reference diagnostic laboratories are discussed in this review. included are data on ticks, mites, lice, fleas, myiasis-causing flies, and bed bugs. the public health importance of these organisms is briefly discussed. the focus is on the morphological identification and proper handling and reporting of cases involving arthropod ectoparasites, particularly those encountered in the united states. o ... | 2014 | 24396136 |
| sensitivity to permethrin in a dermacentor reticulatus population from eastern poland in laboratory study. | the action of chemical compounds on the palaearctic tick d. reticulatus (fabricius) (acari: amblyomminae) has been poorly investigated so far. therefore, the effects of application of permethrin on engorged d. reticulatus females have been assessed, and the survival rate for the different developmental stages of the tick species in its non-parasitic phase of the life cycle was determined upon application of the pyrethroid. | 2014 | 24405550 |
| tick-borne lymphadenopathy-like condition in an african woman in kenya. | a 30-year-old african woman in kenya succumbed to severe swollen regional lymph nodes, development of painful boils and ulcer formation and rashes at specific tick-biting sites together with an intermittent fever and headache following repeated tick bites of rhipicephalus pulchellus. she later developed nuchal lymphadenopathy-like condition and an eschar with edematous margins at bitten sites. a sustained high fever and fatigue then followed. she became well after treatment with antibiotics and ... | 0 | 24497868 |
| an insight into the microbiome of the amblyomma maculatum (acari: ixodidae). | the aim of this study was to survey the bacterial diversity of amblyomma maculatum koch, 1844, and characterize its infection with rickettsia parkeri. pyrosequencing of the bacterial 16s rrna was used to determine the total bacterial population in a. maculatum. pyrosequencing analysis identified rickettsia in a. maculatum midguts, salivary glands, and saliva, which indicates successful trafficking in the arthropod vector. the identity of rickettsia spp. was determined based on sequencing the ric ... | 0 | 24605461 |
| identification of rhipicephalus microplus genes that modulate the infection rate of the rickettsia anaplasma marginale. | arthropod vectors transmit a diversity of animal and human pathogens, ranging from rna viruses to protozoal parasites. chemotherapeutic control of pathogens has classically focused either on insecticides that kill the vector itself or antimicrobials for infected patients. the limitation of the former is that it targets both infected and uninfected vectors and selects for resistant populations while the latter requires prompt and accurate diagnosis. an alternative strategy is to target vector mol ... | 2014 | 24608654 |
| consequences of in vitro host shift for st. louis encephalitis virus. | understanding the potential for host range shifts and expansions of rna viruses is critical to predicting the evolutionary and epidemiological paths of these pathogens. as arthropod-borne viruses (arboviruses) experience frequent spillover from their amplification cycles and are generalists by nature, they are likely to experience a relatively high frequency of success in a range of host environments. despite this, the potential for host expansion, the genetic correlates of adaptation to novel e ... | 2014 | 24643879 |
| comparative off-host survival of larval rocky mountain wood ticks (dermacentor andersoni) collected from ecologically distinct field populations. | dermacentor andersoni (ixodida: ixodidae) stiles, also known as the rocky mountain wood tick (rmwt), is found throughout the western united states and transmits pathogens of importance to human and animal health. the distributions and activity patterns of rmwts are shaped by regional climatic variation. however, it is unknown if responses to climatic variation differ across the tick's geographical range. the objective of this narrow study was to test the hypothesis that the responses of rmwts to ... | 2014 | 24665893 |
| coinfection of tick cell lines has variable effects on replication of intracellular bacterial and viral pathogens. | ticks transmit various human and animal microbial pathogens and may harbour more than one pathogen simultaneously. both viruses and bacteria can trigger, and may subsequently suppress, vertebrate host and arthropod vector anti-microbial responses. microbial coinfection of ticks could lead to an advantage or disadvantage for one or more of the microorganisms. in this preliminary study, cell lines derived from the ticks ixodes scapularis and ixodes ricinus were infected sequentially with 2 arthrop ... | 2014 | 24685441 |
| the tick salivary protein sialostatin l2 inhibits caspase-1-mediated inflammation during anaplasma phagocytophilum infection. | saliva from arthropod vectors facilitates blood feeding by altering host inflammation. whether arthropod saliva counters inflammasome signaling, a protein scaffold that regulates the activity of caspase-1 and cleavage of interleukin-1β (il-1β) and il-18 into mature molecules, remains elusive. in this study, we provide evidence that a tick salivary protein, sialostatin l2, inhibits inflammasome formation during pathogen infection. we show that sialostatin l2 targets caspase-1 activity during host ... | 2014 | 24686067 |
| occurrence and county-level distribution of ticks (acari: ixodoidea) in nebraska using passive surveillance. | a 100 yr (1911-2011) examination of tick submissions was compiled from the u.s. national tick collection and three state databases to determine tick species occurrence in nebraska sixteen tick species were identified including amblyomma americanum (l.), dermacentor variabilis (say), dermacentor albipictus (packard), dermacentor andersoni stiles, haemaphysalis leporispalustris (packard), rhipicephalus sanguineus (latreille), and otobius megrini (dughs). amblyomma maculatum koch and ixodes scapula ... | 2014 | 24724283 |
| global transcriptional analysis reveals surface remodeling of anaplasma marginale in the tick vector. | pathogens dependent upon vectors for transmission to new hosts undergo environment specific changes in gene transcription dependent on whether they are replicating in the vector or the mammalian host. differential gene transcription, especially of potential vaccine candidates, is of interest in anaplasma marginale, the tick-borne causative agent of bovine anaplasmosis. | 2014 | 24751137 |
| detection of rickettsia rickettsii, rickettsia parkeri, and rickettsia akari in skin biopsy specimens using a multiplex real-time polymerase chain reaction assay. | rickettsia rickettsii, rickettsia parkeri, and rickettsia akari are the most common causes of spotted fever group rickettsioses indigenous to the united states. infected patients characteristically present with a maculopapular rash, often accompanied by an inoculation eschar. skin biopsy specimens are often obtained from these lesions for diagnostic evaluation. however, a species-specific diagnosis is achieved infrequently from pathologic specimens because immunohistochemical stains do not diffe ... | 2014 | 24829214 |
| ticks (acari: ixodidae) on small mammals in kootenay national park, british columbia, canada. | two hundred and ninety-one ticks (i.e., 185 larvae, 72 nymphs, and 34 adults) were removed from 153 small mammals comprising six species collected in verdant forest, numa forest, and marble canyon within kootenay national park, british columbia, canada. morphological examination and molecular analyses (i.e., polymerase chain reaction-single-strand conformation polymorphism [pcr-sscp] and dna sequencing of the mitochondrial 16s rrna gene) of the ticks revealed that most individuals were ixodes an ... | 2013 | 24843924 |
| murine cutaneous responses to the rocky mountain spotted fever vector, dermacentor andersoni, feeding. | tick salivary glands produce complex cocktails of bioactive molecules that facilitate blood feeding and pathogen transmission by modulating host hemostasis, pain/itch responses, wound healing, and both innate and adaptive immunity. in this study, cutaneous responses at dermacentor andersoni bite-sites were analyzed using affymetrix mouse genome arrays and histopathology at 12, 48, 96 and 120 h post- infestation (hpi) during primary infestations and 120 hpi during secondary infestations. the micr ... | 2014 | 24847317 |
| salivary gland degeneration and ovary development in the rocky mountain wood tick, dermacentor andersoni stiles (acari: ixodidae). ii. determination of the 'critical weight'. | the feeding cycle of female ixodid ticks is divided into preparatory, slow, and rapid feeding phases. when a female amblyomma hebraeum is removed from the host after achieving a minimum size of about 10-13× the unfed weight, various physiological and behavioural changes occur: (a) haemolymph ecdysteroid concentration rises dramatically, (b) the tick does not reattach to the host when given the opportunity, (c) its salivary glands degenerate within about 4 days (if mated) or 8 days (if virgin), a ... | 2014 | 24865927 |
| cultivation of rickettsia amblyommii in tick cells, prevalence in florida lone star ticks (amblyomma americanum). | rickettsia 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 ... | 2014 | 24927809 |
| the salivary secretome of the biting midge, culicoides sonorensis. | culicoides biting midges (diptera: ceratopogonidae) are hematophagous insects with over 1400 species distributed throughout the world. many of these species are of particular agricultural importance as primary vectors of bluetongue and schmallenberg viruses, yet little is known about culicoides genomics and proteomics. detailed studies of members from other blood-feeding dipteran families, including those of mosquito (culicidae) and black fly (simuliidae), have shown that protein components with ... | 2014 | 24949243 |
| phylogeography of rickettsia rickettsii genotypes associated with fatal rocky mountain spotted fever. | rocky mountain spotted fever (rmsf), a tick-borne zoonosis caused by rickettsia rickettsii, is among the deadliest of all infectious diseases. to identify the distribution of various genotypes of r. rickettsii associated with fatal rmsf, we applied molecular typing methods to samples of dna extracted from formalin-fixed, paraffin-embedded tissue specimens obtained at autopsy from 103 case-patients from seven countries who died of rmsf. complete sequences of one or more intergenic regions were am ... | 2014 | 24957541 |
| a 24-48 h fed amblyomma americanum tick saliva immuno-proteome. | 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 antibo ... | 2014 | 24962723 |
| salivary gland degeneration and ovarian development in the rocky mountain wood tick, dermacentor andersoni stiles (acari: ixodidae). i. post-engorgement events. | it is well known that female ixodid ticks undergo salivary gland degeneration and the greater part of ovarian development following engorgement. the process has been particularly well studied in amblyomma hebraeum, including the hormonal control of these processes. the purpose of this study, and the second one in this series, is to compare the processes in dermacentor andersoni with those of a. hebraeum. a major difference between the two species is that virgin female d. andersoni feed to a much ... | 2014 | 24973274 |
| are ticks venomous animals? | as an ecological adaptation venoms have evolved independently in several species of metazoa. as haematophagous arthropods ticks are mainly considered as ectoparasites due to directly feeding on the skin of animal hosts. ticks are of major importance since they serve as vectors for several diseases affecting humans and livestock animals. ticks are rarely considered as venomous animals despite that tick saliva contains several protein families present in venomous taxa and that many ixodida genera ... | 2014 | 25006341 |
| immunization-induced anaplasma marginale-specific t-lymphocyte responses impaired by a. marginale infection are restored after eliminating infection with tetracycline. | infection of cattle with anaplasma marginale fails to prime sustained effector/memory t-cell responses, and high bacterial load may induce antigen-specific cd4 t exhaustion and deletion. we tested the hypothesis that clearance of persistent infection restores the exhausted t-cell response. we show that infection-induced t-cell exhaustion, characterized as loss of antigen-specific proliferation, and gamma interferon (ifn-γ) and tumor necrosis factor alpha (tnf-α) production are partially restored ... | 2014 | 25008904 |
| ticks infesting humans in italy and associated pathogens. | ticks may transmit a large variety of pathogens, which cause illnesses in animals and humans, commonly referred to as to tick-borne diseases (tbds). the incidence of human tbds in italy is underestimated because of poor surveillance and the scant amount of studies available. | 2014 | 25023709 |
| genetic identification of rickettsial isolates from fatal cases of brazilian spotted fever and comparison with rickettsia rickettsii isolates from the american continents. | fifteen bacterial isolates from spotted fever group rickettsiosis in brazil were genetically identified as rickettsia rickettsii. in a phylogenetic analysis with other r. rickettsii isolates from genbank, the central/south american isolates showed low polymorphism and formed a clade distinct from two north american clades, with the north american clades having greater in-branch polymorphism. | 2014 | 25078908 |
| inadequacy of igm antibody tests for diagnosis of rocky mountain spotted fever. | among 13 suspected rocky mountain spotted fever (rmsf) cases identified through an enhanced surveillance program in tennessee, antibodies to rickettsia rickettsii were detected in 10 (77%) patients using a standard indirect immunofluorescent antibody (ifa) assay. immunoglobulin m (igm) antibodies were observed for 6 of 13 patients (46%) without a corresponding development of igg, and for 3 of 10 patients (30%) at least 1 year post-onset. however, recent infection with a spotted fever group ricke ... | 2014 | 25092818 |
| ixodes pacificus ticks maintain embryogenesis and egg hatching after antibiotic treatment of rickettsia endosymbiont. | rickettsia is a genus of intracellular bacteria that causes a variety of diseases in humans and other mammals and associates with a diverse group of arthropods. although rickettsia appears to be common in ticks, most rickettsia-tick relationships remain generally uncharacterized. the most intimate of these associations is rickettsia species phylotype g021, a maternally and transstadially transmitted endosymbiont that resides in 100% of i. pacificus in california. we investigated the effects of t ... | 2014 | 25105893 |
| proteomics informed by transcriptomics identifies novel secreted proteins in dermacentor andersoni saliva. | dermacentor andersoni, known as the rocky mountain wood tick, is found in the western united states and transmits pathogens that cause diseases of veterinary and public health importance including rocky mountain spotted fever, tularemia, colorado tick fever and bovine anaplasmosis. tick saliva is known to modulate both innate and acquired immune responses, enabling ticks to feed for several days without detection. during feeding ticks subvert host defences such as hemostasis and inflammation, wh ... | 2014 | 25110293 |
| feeding period required by amblyomma aureolatum ticks for transmission of rickettsia rickettsii to vertebrate hosts. | rocky mountain spotted fever is endemic to the são paulo metropolitan area, brazil, where the etiologic agent, rickettsia rickettsii, is transmitted to humans by adult amblyomma aureolatum ticks. we determined the minimal feeding period required by a. aureolatum nymphs and adults to transmit r. rickettsii to guinea pigs. unfed nymphs and unfed adult ticks had to be attached to the host for >10 hours to transmit r. rickettsii. in contrast, fed ticks needed a minimum of 10 minutes of attachment to ... | 0 | 25148391 |
| population-based passive tick surveillance and detection of expanding foci of blacklegged ticks ixodes scapularis and the lyme disease agent borrelia burgdorferi in ontario, canada. | we identified ticks submitted by the public from 2008 through 2012 in ontario, canada, and tested blacklegged ticks ixodes scapularis for borrelia burgdorferi and anaplasma phagocytophilum. among the 18 species of ticks identified, i. scapularis, dermacentor variabilis, ixodes cookei and amblyomma americanum represented 98.1% of the 14,369 ticks submitted. rates of blacklegged tick submission per 100,000 population were highest in ontario's eastern region; d. variabilis in central west and easte ... | 2014 | 25171252 |
| the sialotranscriptome of amblyomma triste, amblyomma parvum and amblyomma cajennense ticks, uncovered by 454-based rna-seq. | tick salivary constituents antagonize inflammatory, immune and hemostatic host responses, favoring tick blood feeding and the establishment of tick-borne pathogens in hosts during hematophagy. amblyomma triste, a. cajennense and a. parvum ticks are very important in veterinary and human health because they are vectors of the etiological agents for several diseases. insights into the tick salivary components involved in blood feeding are essential to understanding vector-pathogen-host interaction ... | 2014 | 25201527 |
| infection with colorado tick fever virus among humans and ticks in a national park and forest, wyoming, 2010. | colorado tick fever (ctf) is an underreported tick-borne viral disease occurring in the western united states. ctf illness includes fever, headache, and severe myalgia lasting for weeks. wyoming has one of the highest ctf incidence rates with approximately 30% of infected persons reporting tick exposure in a wyoming national park or forest before symptom onset. we assessed ctf virus infections among humans and dermacentor andersoni ticks in grand teton national park (grte) and bridger-teton nati ... | 2014 | 25229706 |
| influence of temperature on oviposition by dermacentor andersoni (acari: ixodidae). | the effects of temperature on oviposition by dermacentor andersoni (stiles) was examined using replete females ranging in weight from 30 to 1,198 mg. survivorship was >96% during the preoviposition periods and declined during oviposition period. egg production peaked earlier and at greater levels as temperature increased. longevity, preoviposition period, and oviposition period declined as temperature increased. replete weight had minor effects on measures of time, but smaller females tended to ... | 2014 | 25276920 |
| anaplasma marginale superinfection attributable to pathogen strains with distinct genomic backgrounds. | strain superinfection occurs when a second pathogen strain infects a host already infected with a primary strain. the selective pressures that drive strain divergence, which underlies superinfection, and allow penetration of a new strain into a host population are critical knowledge gaps relevant to shifts in infectious disease epidemiology. in regions of endemicity with a high prevalence of infection, broad population immunity develops against anaplasma marginale, a highly antigenically variant ... | 2014 | 25287920 |
| peripheral neuropathy due to vitamin deficiency, toxins, and medications. | peripheral neuropathies secondary to vitamin deficiencies, medications, or toxins are frequently considered but can be difficult to definitively diagnose. accurate diagnosis is important since these conditions are often treatable and preventable. this article reviews the key features of different types of neuropathies caused by these etiologies and provides a comprehensive list of specific agents that must be kept in mind. | 0 | 25299283 |
| bilateral mandibular pyogranulomatous lymphadenitis and pulmonary nodules in a dog with bartonella henselae bacteremia. | this report describes a 2-year-old collie dog with pulmonary nodules, visualized by computed tomographic (ct) scan, with evidence of bartonella henselae bacteremia and pyogranulomatous lymphadenitis. clinical signs resolved with antimicrobial therapy. | 2014 | 25320386 |
| high prevalence of rickettsia africae variants in amblyomma variegatum ticks from domestic mammals in rural western kenya: implications for human health. | tick-borne spotted fever group (sfg) rickettsioses are emerging human diseases caused by obligate intracellular gram-negative bacteria of the genus rickettsia. despite being important causes of systemic febrile illnesses in travelers returning from sub-saharan africa, little is known about the reservoir hosts of these pathogens. we conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western kenya. of the 100 serum specimens tested from each species of domestic r ... | 0 | 25325312 |
| restriction of francisella novicida genetic diversity during infection of the vector midgut. | the genetic diversity of pathogens, and interactions between genotypes, can strongly influence pathogen phenotypes such as transmissibility and virulence. for vector-borne pathogens, both mammalian hosts and arthropod vectors may limit pathogen genotypic diversity (number of unique genotypes circulating in an area) by preventing infection or transmission of particular genotypes. mammalian hosts often act as "ecological filters" for pathogen diversity, where novel variants are frequently eliminat ... | 2014 | 25392914 |
| identification of novel coxiella burnetii genotypes from ethiopian ticks. | coxiella burnetii, the etiologic agent of q fever, is a highly infectious zoonotic bacterium. genetic information about the strains of this worldwide distributed agent circulating on the african continent is limited. the aim of the present study was the genetic characterization of c. burnetii dna samples detected in ticks collected from ethiopian cattle and their comparison with other genotypes found previously in other parts of the world. | 2014 | 25423309 |
| pathogens in ticks collected from dogs in berlin/brandenburg, germany. | tick-borne diseases are a major health risk for humans and dogs. in addition to collection and analysis of questing ticks, analysis of host-associated ticks for the presence of pathogens is a valuable method to gain insight into transmission patterns of tick-borne diseases. | 2014 | 25441762 |
| community-based control of the brown dog tick in a region with high rates of rocky mountain spotted fever, 2012-2013. | rocky mountain spotted fever (rmsf) transmitted by the brown dog tick (rhipicephalus sanguineus sensu lato) has emerged as a significant public health risk on american indian reservations in eastern arizona. during 2003-2012, more than 250 rmsf cases and 19 deaths were documented among arizona's american indian population. the high case fatality rate makes community-level interventions aimed at rapid and sustained reduction of ticks urgent. beginning in 2012, a two year pilot integrated tick pre ... | 2014 | 25479289 |
| tick-borne encephalitis virus subtypes emerged through rapid vector switches rather than gradual evolution. | tick-borne encephalitis is the most important human arthropod-borne virus disease in europe and russia, with an annual incidence of about 13 thousand people. tick-borne encephalitis virus (tbev) is distributed in the natural foci of forest and taiga zones of eurasia, from the pacific to the atlantic coast. currently, there are three mutually exclusive hypotheses about the origin and distribution of tbev subtypes, although they are based on the same assumption of gradual evolution. recently, we h ... | 2014 | 25540692 |
| sexual differences in the sialomes of the zebra tick, rhipicephalus pulchellus. | ticks rely exclusively on vertebrate blood for their survival. during feeding ticks inject into their hosts a sophisticated salivary potion that overcomes host hemostasis and adverse inflammatory responses. these mediators may also enhance pathogen transmission. knowledge of the tick salivary protein repertoire may lead to vaccine targets to disrupt feeding and/or parasite transmission as well as to the discovery of novel pharmacological agents. male saliva may also assist reproduction because m ... | 2015 | 25576852 |
| immunosuppressive effects of amblyomma cajennense tick saliva on murine bone marrow-derived dendritic cells. | dendritic cells (dcs) are professional antigen-presenting cells with vital roles in the activation of host immunity. ticks are bloodsucking arthropods that secrete bioactive compounds with immunomodulatory properties via their saliva. it is known that some tick species modulate the biology of dcs with different intensities; however, studies on amblyomma cajennense, the cayenne tick, have not yet been performed, although this species is considered one of the most capable of modulating immune resp ... | 2015 | 25586117 |
| reduced infectivity in cattle for an outer membrane protein mutant of anaplasma marginale. | anaplasma marginale is the causative agent of anaplasmosis in cattle. transposon mutagenesis of this pathogen using the himar1 system resulted in the isolation of an omp10 operon insertional mutant referred to as the omp10::himar1 mutant. the work presented here evaluated if this mutant had morphological and/or growth rate defects compared to wild-type a. marginale. results showed that the morphology, developmental cycle, and growth in tick and mammalian cell cultures are similar for the mutant ... | 2015 | 25595772 |
| comparative genome sequencing of rickettsia rickettsii strains that differ in virulence. | rickettsia rickettsii is an obligate intracellular pathogen that is the causative agent of rocky mountain spotted fever. strains of r. rickettsii differ dramatically in virulence. in a guinea pig model of infection, the severity of disease as assessed by fever response varies from the most virulent, sheila smith, to iowa, which causes no fever. to identify potential determinants of virulence in r. rickettsii, the genomes of two additional strains were sequenced for comparison to known sequences ... | 2015 | 25644009 |
| histoarchitecture of the ovary of rhipicephalus (boophilus) annulatus during pre- and postengorgement period. | the present communication describes the detailed day wise study of histological changes of the ovary of rhipicephalus (boophilus) annulatus in the postengorgement period together with the systematic classification of their oocytes. the ovary of r. (b.) annulatus is panoistic type with an asynchronous development of oocytes. all the stages (ii, iii, iv, and v) of oocytes except stage i were similar to r. (b.) microplus. the stage i oocytes showed basophilia, which was not reported earlier in othe ... | 2015 | 25664337 |
| antiviral responses of arthropod vectors: an update on recent advances. | arthropod vectors, such as mosquitoes, ticks, biting midges and sand flies, transmit many viruses that can cause outbreaks of disease in humans and animals around the world. arthropod vector species are invading new areas due to globalisation and environmental changes, and contact between exotic animal species, humans and arthropod vectors is increasing, bringing with it the regular emergence of new arboviruses. for future strategies to control arbovirus transmission, it is important to improve ... | 2014 | 25674592 |