Are ticks venomous animals?

[Introduction]: 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 can induce paralysis and other types of toxicoses. Tick saliva was previously proposed as a special kind of venom since tick venom is used for blood feeding that counteracts host defense mechanisms. As a result, the present study provides evidence to reconsider the venomous properties of tick saliva. [Results]: Based on our extensive literature mining and in silico research, we demonstrate that ticks share several similarities with other venomous taxa. Many tick salivary protein families and their previously described functions are homologous to proteins found in scorpion, spider, snake, platypus and bee venoms. This infers that there is a structural and functional convergence between several molecular components in tick saliva and the venoms from other recognized venomous taxa. We also highlight the fact that the immune response against tick saliva and venoms (from recognized venomous taxa) are both dominated by an allergic immunity background. Furthermore, by comparing the major molecular components of human saliva, as an example of a non-venomous animal, with that of ticks we find evidence that ticks resemble more venomous than non-venomous animals. Finally, we introduce our considerations regarding the evolution of venoms in Arachnida. [Conclusions]: Taking into account the composition of tick saliva, the venomous functions that ticks have while interacting with their hosts, and the distinguishable differences between human (non-venomous) and tick salivary proteins, we consider that ticks should be referred to as venomous ectoparasites.JJV was sponsored by project CZ.1.07/2.3.00/30.0032, co-financed by the European Social Fund and the state budget of the Czech Republic. ACC was supported by a grant from the Ministère de l’Education Supérieure et de la Recherche of France.Peer Reviewe

Crecimiento Urbano y Cambio de Uso de Suelo. El Caso del Oriente de la Zona Metropolitana de Toluca, Méxcio

El Área de Estudio es la Parte Oriente de la Zona Metropolitana de Toluca y Está Conformada por los Municipios de Lerma, Metepec, Ocoyoacac, y San Mateo Atenco.Se Efectuó un Análisis Retrospectivo-Lineal a través de Variables que Permitieron Describir y Explicar Factores Socio-Territoriales que Han Promovido el Cambio de Uso de Suelo

Cancer research meets tick vectors for infectious diseases

Comment.Peer Reviewe

The glycoprotein TRP36 of Ehrlichia sp. UFMG-EV and related cattle pathogen Ehrlichia sp. UFMT-BV evolved from a highly variable clade of E. canis under adaptive diversifying selection

[Background]: A new species of Ehrlichia, phylogenetically distant from E. ruminantium, was found in 2010 infecting cattle in Canada. In 2012 and 2013, we reported the in vitro propagation, molecular and ultrastructural characterization of Ehrlichia sp. UFMG-EV (E. mineirensis), a new species of Ehrlichia isolated from the haemolymph of Brazilian Rhipicephalus (Boophilus) microplus ticks. A new organism, named Ehrlichia sp. UFMT-BV, closely related to Ehrlichia sp. UFMG-EV, was recently described in Brazil and after experimental infection it was shown to be pathogenic for cattle. This new emerging clade of cattle Ehrlichia pathogens is closely related to E. canis. The major immunogenic Tandem Repeat Protein (TRP36; also known as gp36) is extensively used to characterize the genetic diversity of E. canis. Homologs of TRP36 were found in both Ehrlichia sp. UFMG-EV and Ehrlichia sp. UFMT-BV. [Findings]: Herein, we characterized the evolution of this new Ehrlichia clade using TRP36 sequences. Our working hypothesis is that Ehrlichia sp. UFMG-EV and related microorganisms evolved from a highly variable E. canis clade. In support of our hypothesis we found that Ehrlichia sp. UFMG-EV and Ehrlichia sp. UFMT-BV TRP36 evolved from a highly divergent and variable clade within E. canis and this clade evolved under episodic diversifying selection with a high proportion of sites under positive selection. [Conclusion]: Our results suggest that Ehrlichia sp. UFMG-EV and Ehrlichia sp. UFMT-BV evolved from a variable clade within E. canis.This research was partially supported by the EU FP7 ANTIGONE project number 278976. JJV was sponsored by project CZ.1.07/2.3.00/30.0032, co-financed by the European Social Fund and the state budget of the Czech Republic. ACC was supported by a grant from the Ministère de l’Education Supérieure et de la Recherche of FrancePeer Reviewe

Defensins from the tick Ixodes scapularis are effective against phytopathogenic fungi and the human bacterial pathogen Listeria grayi

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: Ixodes scapularis is the most common tick species in North America and a vector of important pathogens that cause diseases in humans and animals including Lyme disease, anaplasmosis and babesiosis. Tick defensins have been identified as a new source of antimicrobial agents with putative medical applications due to their wide-ranging antimicrobial activities. Two multigene families of defensins were previously reported in I. scapularis. The objective of the present study was to characterise the potential antimicrobial activity of two defensins from I. scapularis with emphasis on human pathogenic bacterial strains and important phytopathogenic fungi. [Methods]: Scapularisin-3 and Scapularisin-6 mature peptides were chemically synthesised. In vitro antimicrobial assays were performed to test the activity of these two defensins against species of different bacterial genera including Gram-positive bacteria Staphylococcus aureus, Staphylococcus epidermidis, and Listeria spp. as well as Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa along with two plant-pathogenic fungi from the genus Fusarium. In addition, the tissue-specific expression patterns of Scapularisin-3 and Scapularisin-6 in I. scapularis midgut, salivary glands and embryo-derived cell lines were determined using PCR. Finally, tertiary structures of the two defensins were predicted and structural analyses were conducted. [Results]: Scapularisin-6 efficiently killed L. grayi, and both Scapularisin-3 and Scapularisin-6 caused strong inhibition (IC value: ∼1 μM) of the germination of plant-pathogenic fungi Fusarium culmorum and Fusarium graminearum. Scapularisin-6 gene expression was observed in I. scapularis salivary glands and midgut. However, Scapularisin-3 gene expression was only detected in the salivary glands. Transcripts from the two defensins were not found in the I. scapularis tick cell lines ISE6 and ISE18. [Conclusion]: Our results have two main implications. Firstly, the anti-Listeria and antifungal activities of Scapularisin-3 and Scapularisin-6 suggest that these peptides may be useful for (i) treatment of antibiotic-resistant L. grayi in humans and (ii) plant protection. Secondly, the antimicrobial properties of the two defensins described in this study may pave the way for further studies regarding pathogen invasion and innate immunity in I. scapularis.Miray Tonk is a Marie Curie Early Stage Researcher supported by the POSTICK ITN (Post-graduate training network for capacity building to control ticks and tick-borne diseases) within the FP7- PEOPLE – ITN programme (EU Grant No. 238511). This project was partially supported by the Grant Agency of the Czech Republic (GACR P302/11/1901) and with institutional support RVO: 60077344 from Biology Centre, Institute of Parasitology as well as grant ANTIGONE (EU-7FP; 278976). James J. Valdés was sponsored by project CZ.1.07/2.3.00/30.0032, co-financed by the European Social Fund and the state budget of the Czech Republic. Radek Šíma was supported by the Grant 13-12816P (GA CR). Mohammad Rahnamaeian and Andreas Vilcinskas acknowledge the Ministry for Science and Art of the State of Hesse (Germany) for funding the LOEWE Center of Insect Biotechnology and Bioresources. Zdeněk Franta was supported by Alexander von Humboldt Research Fellowship for Postdoctoral Researchers.Peer Reviewe

New species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus shows an ortholog of the E. canis major immunogenic glycoprotein gp36 with a new sequence of tandem repeats

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: Ehrlichia species are the etiological agents of emerging and life-threatening tick-borne human zoonoses that inflict serious and fatal infections in companion animals and livestock. The aim of this paper was to phylogeneticaly characterise a new species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus from Minas Gerais, Brazil. [Methods]: The agent was isolated from the hemolymph of Rhipicephalus (B.) microplus engorged females that had been collected from naturally infested cattle in a farm in the state of Minas Gerais, Brazil. This agent was then established and cultured in IDE8 tick cells. The molecular and phylogenetic analysis was based on 16S rRNA, groEL, dsb, gltA and gp36 genes. We used the maximum likelihood method to construct the phylogenetic trees. [Results]: The phylogenetic trees based on 16S rRNA, groEL, dsb and gltA showed that the Ehrlichia spp isolated in this study falls in a clade separated from any previously reported Ehrlichia spp. The molecular analysis of the ortholog of gp36, the major immunoreactive glycoproteins in E. canis and ortholog of the E. chaffeensis gp47, showed a unique tandem repeat of 9 amino acids (VPAASGDAQ) when compared with those reported for E. canis, E. chaffeensis and the related mucin-like protein in E. ruminantium. [Conclusions]: Based on the molecular and phylogenetic analysis of the 16S rRNA, groEL, dsb and gltA genes we concluded that this tick-derived microorganism isolated in Brazil is a new species, named E. mineirensis (UFMG-EV), with predicted novel antigenic properties in the gp36 ortholog glycoprotein. Further studies on this new Ehrlichia spp should address questions about its transmissibility by ticks and its pathogenicity for mammalian hosts.A. Cabezas Cruz is a Marie Curie Early Stage Researcher (ESR) supported by the POSTICK ITN (Post-graduate training network for capacity building to control ticks and tick-borne diseases) within the FP7- PEOPLE – ITN programme (EU Grant No. 238511).Peer Reviewe

Transcranial focal electrical stimulation via concentric ring electrodes in freely moving cats: Antiepileptogenic and postictal effects

Transcranial focal electrical stimulation (TFS) via tripolar concentric ring electrodes (TCRE), tripolar TFS, is proposed to treat pharmacoresistant epilepsy. We determined the effect of tripolar TFS on electrical amygdaloid kindling (AK) in freely moving cats. Fifteen cats were bilaterally implanted with electrodes in the amygdala (AM) and prefrontal cortex and assigned to three groups: the control group, which only received AK; the tripolar TFS before AK group, in which TCREs were placed over the vertex and tripolar TFS (300 Hz, 200 μs biphasic equal charge, square pulses) was delivered for 40 min just prior to AK; and the tripolar TFS after AK group, in which the TCREs were placed over the temporal bone ipsilateral to the kindled AM, while tripolar TFS was administered for 2 min just after AK onset for 40 days, and, thereafter, only AK was applied. AK was applied daily until all animals reached kindling stage VI. A three concentric spheres finite element cat head model was developed to analyze the electric fields caused by tripolar TFS. Tripolar TFS after AK inhibited kindling development. Animals with tripolar TFS after AK remained at the focal seizure stages for 20 days after tripolar TFS cessation and required 80.0 ± 15.42 AK stimulations to reach stage VI, significantly higher than TFS before AK, and control (P \u3c .001). Tripolar TFS before AK did not show signs of protection against epileptogenesis. The finite modeling of tripolar TFS showed that the electric field is \u3e0.3 mV/mm at depths less than approximately 12.6 mm in the cat brain, which should be strong enough to alter brain activity. In conclusion, tripolar TFS applied via a TCRE over the ipsilateral temporal area significantly delayed AK. This taken together with other reports of tripolar TFS aborting seizures in acute seizure models suggests that tripolar TFS is a promising new modality that should be considered for further testing

Tick galactosyltransferases are involved in a-Gal synthesis and play a role during Anaplasma phagocytophilum infection and Ixodes scapularis tick vector development

The carbohydrate Gala1-3Galß1-(3)4GlcNAc-R (a-Gal) is produced in all mammals except for humans, apes and old world monkeys that lost the ability to synthetize this carbohydrate. Therefore, humans can produce high antibody titers against a-Gal. Anti-a-Gal IgE antibodies have been associated with tick-induced allergy (i.e. a-Gal syndrome) and anti-a-Gal IgG/IgM antibodies may be involved in protection against malaria, leishmaniasis and Chagas disease. The a-Gal on tick salivary proteins plays an important role in the etiology of the a-Gal syndrome. However, whether ticks are able to produce endogenous a-Gal remains currently unknown. In this study, the Ixodes scapularis genome was searched for galactosyltransferases and three genes were identified as potentially involved in the synthesis of a-Gal. Heterologous gene expression in a-Gal-negative cells and gene knockdown in ticks confirmed that these genes were involved in a-Gal synthesis and are essential for tick feeding. Furthermore, these genes were shown to play an important role in tick-pathogen interactions. Results suggested that tick cells increased a-Gal levels in response to Anaplasma phagocytophilum infection to control bacterial infection. These results provided the molecular basis of endogenous a-Gal production in ticks and suggested that tick galactosyltransferases are involved in vector development, tick-pathogen interactions and possibly the etiology of a-Gal syndrome in humans

Functional and Immunological Relevance of Anaplasma marginale Major Surface Protein 1a Sequence and Structural Analysis.

Bovine anaplasmosis is caused by cattle infection with the tick-borne bacterium, Anaplasma marginale. The major surface protein 1a (MSP1a) has been used as a genetic marker for identifying A. marginale strains based on N-terminal tandem repeats and a 5'-UTR microsatellite located in the msp1a gene. The MSP1a tandem repeats contain immune relevant elements and functional domains that bind to bovine erythrocytes and tick cells, thus providing information about the evolution of host-pathogen and vector-pathogen interactions. Here we propose one nomenclature for A. marginale strain classification based on MSP1a. All tandem repeats among A. marginale strains were classified and the amino acid variability/frequency in each position was determined. The sequence variation at immunodominant B cell epitopes was determined and the secondary (2D) structure of the tandem repeats was modeled. A total of 224 different strains of A. marginale were classified, showing 11 genotypes based on the 5'-UTR microsatellite and 193 different tandem repeats with high amino acid variability per position. Our results showed phylogenetic correlation between MSP1a sequence, secondary structure, B-cell epitope composition and tick transmissibility of A. marginale strains. The analysis of MSP1a sequences provides relevant information about the biology of A. marginale to design vaccines with a cross-protective capacity based on MSP1a B-cell epitopes

Implante coclear y terapia auditivo verbal en el Hospital Pediátrico Provincial Pepe Portilla

Introduction: oral language is mainly based on acoustic information. Hypoacusis is the partial loss of hearing capacity; from 40 decibels and above, its presence has an impact on the acquisition of language functions and the overall development of the child.Objective: to describe the evolution of a clinical case of a hearing impaired patient with cochlear implant after the application of an auditory-verbal therapy.Case report: a 10-year-old and 7 months boy with delayed language development due to a Deep Bilateral Sensorineural Hearing Loss of presumed congenital origin, after being diagnosed early with this disease he was included in the National Cochlear Implant Program in order to improve his hearing abilities and thus facilitate auditory feedback. After surgery, he began to undergo auditory-verbal therapy to promote the proper acquisition of language functions.Conclusions: hearing impaired children can learn to listen and speak through early diagnosis and intervention, appropriate technology and with the perseverance of parents and therapists who share the vision of giving voice to the future of the child. It is important to keep in mind that the appropriate treatment, the intellectual capacity of children and the family environment condition the successful evolution of the therapies applied.Introducción: el lenguaje oral está basado principalmente en la información acústica. La hipoacusia es la pérdida parcial de la capacidad auditiva. A partir de los 40 decibelios en adelante, su presencia repercute en la adquisición de las funciones del lenguaje y el desarrollo integral del niño.Objetivo: describir la evolución de un caso clínico hipoacúsico con implante coclear, tras la aplicación de una terapia auditivo-verbal.Presentación de caso: se presenta un niño de 10 años y siete meses de edad, con retraso en el desarrollo del lenguaje debido a una Hipoacusia Neurosensorial Bilateral Profunda de presunto origen congénito. Después de ser diagnosticado tempranamente con esta enfermedad, fue incluido en el Programa Nacional de Implante Coclear con vistas a mejorar sus capacidades auditivas y facilitar así la retroalimentación auditiva. Luego de la cirugía se le comenzó a aplicar una terapia auditivo verbal para propiciar la adquisición adecuada de las funciones del lenguaje.Conclusiones: los niños con problemas de audición pueden aprender a escuchar y a hablar mediante un diagnóstico y una intervención temprana, la tecnología apropiada y con la dedicación de padres y terapeutas que comparten la visión de darle voz al futuro del niño. Es importante tener en cuenta que el tratamiento adecuado, la capacidad intelectual de los niños y el ambiente familiar, condicionan la evolución exitosa de las terapias aplicadas