Tick bites and skin rashes

Interactions of Drug Doxycycline Hyclate with Galactitol in Aqueous Solutions at Different Temperatures by Volumetric and Acoustic Methods

The experimental values of density, ρ and speed of sound, u of doxycycline hyclate drug (0.002–0.014) mol kg−1 in water and (0.1, 0.2 and 0.4) mol kg−1 of aqueous galactitol solutions at temperatures T = (303.15, 308.15 and 313.15) K and at atmospheric pressure have been reported in the present communication. From the experimental values, various derived parameters such as apparent molar volume (Φ V), apparent molar isentropic compression (Φ K), limiting apparent molar volume ( Φ v o $\phi_{\text{v}}^{\text{o}}$ ), limiting apparent molar isentropic compression ( Φ K o $\phi_{\text{K}}^{\text{o}}$ ), limiting apparent molar volume of transfer (Δ Φ V O $\phi_{\text{V}}^{\text{O}}$ ), limiting apparent molar isentropic compression of transfer (Δ Φ K O $\phi_{\text{K}}^{\text{O}}$ ), limiting apparent molar expansibility ( Φ E o $\phi_{\text{E}}^{\text{o}}$ ), thermal expansion coefficient (α) and acoustic parameters like isentropic compressibility ( κ S ) $({{\kappa}_{\text{S}}})$ , intermolecular free length (Lf), and specific acoustic impedance (Z) were calculated. The structure-making behaviour of DH in aqueous galactitol solution was determined on the basis of Hepler’s Equation i.e. on the basis of sign of ( d 2 Φ V O d T 2 ) P ${\left({\frac{{{{\text{d}}^{2}}\phi_{\text{V}}^{\text{O}}}}{{{\text{d}}{{\text{T}}^{2}}}}}\right)_{\text{P}}}$ . The various derived parameters were utilised to interpret the molecular interactions i.e. solute–solute and solute–solvent existing in the studied system.

Cutaneous Findings of Crimean-Congo Hemorrhagic Fever: a Study of 269 Cases

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic viral disease. We aimed to investigate the cutaneous manifestations of CCHF and reveal their associations with fatality. Two hundred and sixty-nine patients diagnosed with CCHF were assessed. Skin findings were observed in 170 (63.2%) patients. A facial rash was the most common cutaneous finding (n = 82, 30.5%). In severe cases, hemorrhagic cutaneous manifestations (petechiae and ecchymoses) were recognized. A statistically significant correlation was obtained between cutaneous manifestations and fatality, and it was determined that there was a strong positive correlation between fatality and ecchymosis (r = 567, p < 0.001). In addition, a logistic regression analysis was performed, and death occurred 4.69 times more in those with skin signs than in those without. We hypothesize that CCHF patients with ecchymosis are at the highest risk and that cutaneous findings can contribute to the prognosis of CCHF.

Doxycycline hydrate and doxycycline hydrochloride dihydrate – crystal structure and charge density analysis

High-resolution low-temperature X-ray diffraction experiments for doxycycline monohydrate and hydrochloride dihydrate have been performed. Translation-Libration-Screw (TLS) analysis for both crystal forms as well as the data from neutron diffraction experiment for hydrochloride combined with the Hansen-Coppens formalism resulted in precise charge density distribution models for both the zwitterionic monohydrate and a protonated hydrochloride crystal forms. Their detailed topological analysis suggested that the electron structure of doxycycline’s amide moiety undergoes significant changes during protonation due to formation of a very strong resonance-assisted hydrogen bond. A notably increased participation of amide nitrogen atom and hydrogen-accepting oxygen atom in the resonance upon doxycycline protonation was observed. A comparison of TLS- and neutron data-derived hydrogen parameters confirmed the experimental neutron data to be vital for proper description of intra- and inter-molecular interactions in this compound. Finally, calculated lattice and interaction energies quantified repulsive Dox-Dox interactions in the protonated crystal form of the antibiotic, relating with a good solubility of doxycycline hydrochloride relative to its hydrate.

Interaction of primary mast cells with Borrelia burgdorferi (sensu stricto): role in transmission and dissemination in C57BL/6 mice

Background

Borrelia burgdorferi (sensulato), the causative agent of Lyme borreliosis is a bacterium transmitted by hard ticks, Ixodes spp. Bacteria are injected into the host skin during the tick blood meal with tick saliva. There, Borrelia and saliva interact together with skin cells such as keratinocytes, fibroblasts, mast cells and other specific immune cells before disseminating to target organs.

Methods

To study the role of mast cells in the transmission of Lyme borreliosis, we isolated mouse primary mast cells from bone marrow and incubated them in the presence of Borrelia burgdorferi (sensu stricto) and tick salivary gland extract. We further analyzed their potential role in vivo, in a mouse model of deficient in mast cells (Kit^wsh−/− mice).

Results

To our knowledge, we report here for the first time the bacteria ability to induce the inflammatory response of mouse primary mast cells. We show that OspC, a major surface lipoprotein involved in the early transmission of Borrelia, induces the degranulation of primary mast cells but has a limited effect on the overall inflammatory response of these cells. In contrast, whole bacteria have an opposite effect. We also show that mast cell activation is significantly inhibited by tick salivary gland extract. Finally, we demonstrate that mast cells are likely not the only host cells involved in the early transmission and dissemination of Borrelia since the use of mast cell deficient Kit^wsh−/− mice shows a limited impact on these two processes in the context of this mouse genetic background.

Conclusions

The absence of mast cells did not change the replication rate of Borrelia in the skin. However, in the absence of mast cells, Borrelia dissemination to the joints was faster. Mast cells do not control skin bacterial proliferation during primary infection and the establishment of the primary infection, as shown in the C57BL/6 mouse model studied. Nevertheless, the Borrelia induced cytotokine modulation on mast cells might be involved in long term and/or repeated infections and protect from Lyme borreliosis due to the development of a hypersensitivity to tick saliva.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-017-2243-0) contains supplementary material, which is available to authorized users.

Comparison of Preferred Bite Sites Between Mites and Ticks on Humans in Korea

Identification of mite and tick bite sites provides important clinical information. The predominant mite species in Korea associated with scrub typhus are Leptotrombidium pallidum and Leptotrombidium scutellare The most abundant tick species is Haemaphysalis longicornis To date, there has been no comparative study on preferred bite sites between mites and ticks in humans. This study included a review of medical records and a field study. For mite bite sites, eschars were checked on 506 patients with scrub typhus, confirmed by indirect immunofluorescence assay or nested polymerase chain reaction on the 56-kDa type-specific antigen gene of Orientia tsutsugamushi Tick bite sites were identified and marked on a diagram for 91 patients who experienced tick bites within the previous year through a field epidemiological investigation. The mite and tick bite sites in Koreans were compared. The most frequently observed mite bite sites were the anterior chest, including the axillae (29.1%) and the abdominal region, including the inguinal area (26.1%). Tick bite sites were most frequent on the lower extremities (33.0%), followed by the abdominal region, including the inguinal area (26.4%), and upper extremities (26.4%). The distribution was significantly different between mite and tick bite sites (P < 0.001). There was a statistically significant difference in the mite bite (P = 0.001), but not tick bite sites (P = 0.985), between men and women. This is the first report on the differences between tick and mite bite sites, and may help clinicians reach a rapid diagnosis of mite- or tick-borne infection.

Lyme Borreliosis: An Update for Canadian Dermatologists

Background:

Lyme borreliosis is a multisystemic tick-borne spirochetosis, which may result in dermatologic, musculoskeletal, cardiovascular, and neurologic manifestations.

Objective:

Patients with suspected acute Lyme borreliosis infection may be referred for urgent dermatologic review. Canadian dermatologists should be aware of the latest information regarding the diagnosis and management of Lyme borreliosis.

Methods:

This review is based on a PubMed database search combining the word “Lyme” with variations of the word “Canada.” Data sources included articles from the fields of ecology, epidemiology, laboratory diagnostics, and clinical management.

Conclusion:

In this review, the ecological basis of spirochete transmission by tick vectors is described. The latest available Canadian epidemiologic data are summarized. North American clinical manifestations of Lyme borreliosis are contrasted with European presentations. The Canadian Public Health Laboratory Network's diagnostic guidelines are summarized. Finally, treatment recommendations are outlined.

Lyme disease: Part I. Advances and perspectives

Lyme disease (LD) is an increasingly recognized multisystem, insect-borne zoonosis. Prevalent worldwide, it has a variety of presentations at different stages of infection. The characteristic rash with central clearing known as erythema chronicum migrans, or simply erythema migrans, appears in its first stage. Typical features may be absent, and important variations are evident among cases seen in different parts of the world. LD may be difficult to diagnose clinically; knowledge about its epidemiology and transmission may be of assistance when the diagnosis is unclear. Based upon our experience with LD and a comprehensive literature review, we provide an update of LD epidemiology, pathophysiology, and management. We also cover the three clinical stages of LD that parallel those of syphilis, another spirochetal disease.