Clearance of endosymbionts in the tick vector Rhipicephalus sanguineus

Abstract only availableVector-borne diseases reduce livestock production in areas whose human populations are starving, such as the Tsetse belt in Africa. In the United States, people are infected every year with Lyme disease, Rocky Mountain Spotted Fever, and Human Monocytic Ehrlichiosis. A method of controlling vectors, such as ticks, would have many uses. Previous studies have indicated that all ticks of the species Amblyomma americanum are infected with a Coxiella sp. bacterial symbiont. After treatment with the antibiotics rifampin and tetracycline, nymphs and adults were shown to have lower numbers of this symbiont and treatment of engorged adult females was shown to result in decreased fecundity (Zhong et al. 2007). It was speculated that this Coxiella symbiont plays a vital role in tick fitness and female fecundity. The goals of the current experiment are to: demonstrate the presence of the same or similar symbiont in Rhipicephalus sanguineus adults and larvae, demonstrate clearance of the symbiont in larvae after treatment with antibiotics, observe any negative effects on the fecundity of the treated females, and test the acquisition rate of larvae that feed on a carrier of Ehrlichia canis, a pathogen of which ticks are a vector. A Coxiella sp. symbiont was shown in adult and larvae R. sanguineus using PCR. Adult females were then fed with males on dogs to repletion, with several groups receiving different treatments of antibiotics prior to mating. Three of the treatment groups suffered significantly lower fecundity than the control. DNA from the resulting larvae was PCR assayed for symbionts, and the Coxiella symbiont has been found in lower numbers in the larvae of these treated groups. The next phase of the experiment is to feed symbiont cleared or reduced larvae on an E. canis carrier and compare their rate of acquisition to untreated larvae.Dr. Roger W. Stich, Veterinary Pathobiolog

AMPylation: Something Old is New Again

The post-translational modification AMPylation is emerging as a significant regulatory mechanism in both prokaryotic and eukaryotic biology. This process involves the covalent addition of an adenosine monophosphate to a protein resulting in a modified protein with altered activity. Proteins capable of catalyzing AMPylation, termed AMPylators, are comparable to kinases in that they both hydrolyze ATP and reversibly transfer a part of this primary metabolite to a hydroxyl side chain of the protein substrate. To date, only four AMPylators have been characterized, though many more potential candidates have been identified through amino acid sequence analysis and preliminary in vitro studies. This modification was first discovered over 40 years ago by Earl Stadtman and colleagues through the modification of glutamine synthetase by adenylyl transferase; however research into this mechanism has only just been reenergized by the studies on bacterial effectors. New AMPylators were revealed due to the discovery that a bacterial effector having a conserved Fic domain transfers an AMP group to protein substrates. Current research focuses on identifying and characterizing various types of AMPylators homologous to Fic domains and adenylyl transferase domains and their respective substrates. While all AMPylators characterized thus far are bacterial proteins, the conservation of the Fic domain in eukaryotic organisms suggests that AMPylation is omnipresent in various forms of life and has significant impact on a wide range of regulatory processes

Seismic Monitoring and Baseline Microseismicity in the Rome Trough, Eastern Kentucky

In the central and eastern United States, felt earthquakes likely triggered by fluid injection from oil and gas production or wastewater disposal have dramatically increased in frequency since the onset of the unconventional shale gas and oil boom. In the Rome Trough of eastern Kentucky, fracture stimulations and wastewater injection are ongoing and occur near areas of historical seismic activity. Unlike in surrounding and nearby states (Ohio, West Virginia, and Arkansas), in Kentucky, no seismic events related to subsurface fluid injections have been reported as felt or detected by regional seismic networks, including the Kentucky Seismic and Strong-Motion Network. Oil and gas development of the deep Cambrian Rogersville Shale in the Rome Trough is in a very early stage, and will require horizontal drilling and high-volume hydraulic fracturing. To characterize natural seismicity rates and the conditions that might lead to induced or triggered events, the Kentucky Geological Survey is conducting a collaborative study, the Eastern Kentucky Microseismic Monitoring Project, prior to large-scale oil and gas production and wastewater injection. A temporary network of broadband seismographs was deployed near dense clusters of Class II wastewater-injection wells and near the locations of new, deep oil and gas test wells in eastern Kentucky. Network installation began in mid-2015 and by November 2015, 12 stations were operating, with data acquired in real time and jointly with regional network data. Additional stations were installed between June 2016 and October 2017 in targeted locations. The network improved the monitoring sensitivity near wastewater-injection wells and deep oil and gas test wells by approximately an entire unit of magnitude: With the temporary network, the detectable magnitudes range from 0.7 to 1.0, and without it, the detectable magnitudes range from 1.5 to 1.9. Using the real-time recordings of this network in tandem with the recordings of other temporary and permanent regional seismic stations, we generated a catalog of local seismicity and developed a calibrated magnitude scale. At the time this report was prepared, 151 earthquakes had been detected and located, 38 of which were in the project area, defined as the region bounded by 37.1°N to 38.7°N latitude and 84.5°W to 82.0°W longitude. Only six earthquakes occurred in the Rome Trough of eastern Kentucky, none of which were reported in regional monitoring agency catalogs, and none of which appear to be associated with the deep Rogersville Shale test wells that were completed during the time the network was in operation or with wastewater-injection wells

Manipulation of kinase signaling by bacterial pathogens

Bacterial pathogens use effector proteins to manipulate their hosts to propagate infection. These effectors divert host cell signaling pathways to the benefit of the pathogen and frequently target kinase signaling cascades. Notable pathways that are usurped include the nuclear factor κB (NF-κB), mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/Akt, and p21-activated kinase (PAK) pathways. Analyzing the functions of pathogenic effectors and their intersection with host kinase pathways has provided interesting insights into both the mechanisms of virulence and eukaryotic signaling

Improving Rosacea Outcomes in Skin of Color Patients: A Review on the Nuances in the Treatment and the Use of Cleansers and Moisturizers

BACKGROUNDWhile rosacea is a common inflammatory condition that affects diverse populations, published data in skin of color (SOC) are limited. This review explored nuances in clinical presentation and treatment considerations in SOC patients with rosacea and the role of cleansers and moisturizers in the management of rosacea in these populations. METHODSA panel reviewed and discussed aspects of rosacea in SOC and possible implications for treatment and maintenance. The outcome of these discussions, coupled with the panel's expert opinion and experience was used to define draft statements. After group discussions and an online review process, the panel agreed on the inclusion and wording of five statements. RESULTSStudies and anecdotal clinical experience suggest that rosacea is more common in SOC populations than previously reported. The clinical presentation of rosacea across diverse skin types includes the spectrum of clinical subtypes observed in other populations; however, clinical features may be less conspicuous in individuals with higher skin phototypes and the index of suspicion may be lower in SOC populations. To avoid underdiagnosis, dermatologists should consider rosacea in the differential diagnosis of any patient presenting with a history of skin sensitivity, central facial erythema, papules, and pustules. The compromised barrier in rosacea contributes to skin sensitivity. Studies including Chinese rosacea patients showed that using a moisturizer and sunscreen negatively correlated with rosacea development. CONCLUSIONSThe use of skincare could improve rosacea symptomatology. These products are recommended before and during prescription therapy and as part of a maintenance regimen as adjuncts. J Drugs Dermatol. 2022;21(6):574-580. doi:10.36849/JDD.6838

Racial/Ethnic Variations in Skin Barrier: Implications for Skin Care Recommendations in Skin of Color

Background: Genetic and environmental factors influence stratum corneum (SC) barrier properties and function. Researchers increasingly focus on biophysical studies that may help clinicians provide their patients with an informed choice on tailormade skincare. This literature review on skin barrier properties comparing different ethnic populations aims to offer insights into the information's clinical relevance. Methods: A literature review followed by panel discussions and an online review process aimed to answer the questions: Are there racial/ethnic differences in the SC barrier structure and healthy skin barrier function? Is there a need for specific cleansers and moisturizers? Results: Ethnic categories based on race and ethnicity are often not well defined and inconsistent across different studies. Studies comparing ethnic groups' physical and biochemical skin barrier properties have reported differences in transepidermal water loss (TEWL), skin lipid levels, pH, and mast cell granule size. However, these studies frequently had methodological flaws, mainly were small, and demonstrated conflicting results. The literature suggests racial/ethnic variations in ceramide content, SC structure, and filaggrin mutations. Furthermore, studies have shown a greater burden of pruritus and atopic dermatitis among Black populations. Data on barrier properties in Hispanic/LatinX and South Asian populations are lacking. Conclusion: Robust comparative studies are needed to understand these basic concepts to help tailor skincare and skin of color patients' education