The characterization and manipulation of the bacterial microbiome of the Rocky Mountain wood tick, Dermacentor andersoni

BACKGROUND: In North America, ticks are the most economically impactful vectors of human and animal pathogens. The Rocky Mountain wood tick, Dermacentor andersoni (Acari: Ixodidae), transmits Rickettsia rickettsii and Anaplasma marginale to humans and cattle, respectively. In recent years, studies have shown that symbiotic organisms are involved in a number of biochemical and physiological functions. Characterizing the bacterial microbiome of D. andersoni is a pivotal step towards understanding symbiont-host interactions. FINDINGS: In this study, we have shown by high-throughput sequence analysis that the composition of endosymbionts in the midgut and salivary glands in adult ticks is dynamic over three generations. Four Proteobacteria genera, Rickettsia, Francisella, Arsenophonus, and Acinetobacter, were identified as predominant symbionts in these two tissues. Exposure to therapeutic doses of the broad-spectrum antibiotic, oxytetracycline, affected both proportions of predominant genera and significantly reduced reproductive fitness. Additionally, Acinetobacter, a free-living ubiquitous microbe, invaded the bacterial microbiome at different proportions based on antibiotic treatment status suggesting that microbiome composition may have a role in susceptibility to environmental contaminants. CONCLUSIONS: This study characterized the bacterial microbiome in D. andersoni and determined the generational variability within this tick. Furthermore, this study confirmed that microbiome manipulation is associated with tick fitness and may be a potential method for biocontrol

Pharmacomicrobiomics of antidepressants in depression : a systematic review

This systematic review evaluated the animal and human evidence for pharmacomicrobiomics (PMx) interactions of antidepressant medications. Studies of gut microbiota effects on functional and behavioral effects of antidepressants in human and animal models were identified from PubMed up to December 2022. Risk of bias was assessed, and results are presented as a systematic review following PRISMA guidelines. A total of 28 (21 animal, 7 human) studies were included in the review. The reviewed papers converged on three themes: (1) Antidepressants can alter the composition and metabolites of gut microbiota, (2) gut microbiota can alter the bioavailability of certain antidepressants, and (3) gut microbiota may modulate the clinical or modeled mood modifying effects of antidepressants. The majority (n = 22) of studies had at least moderate levels of bias present. While strong evidence is still lacking to understand the clinical role of antidepressant PMx in human health, there is evidence for interactions among antidepressants, microbiota changes, microbiota metabolite changes, and behavior. Well-controlled studies of the mediating and moderating effects of baseline and treatment-emergent changes in microbiota on therapeutic and adverse responses to antidepressants are needed to better establish a potential role of PMx in personalizing antidepressant treatment selection and response prediction.https://www.mdpi.com/journal/jpmam2024Veterinary Tropical DiseasesSDG-03:Good heatlh and well-bein

Excitons in a Photosynthetic Light-Harvesting System: A Combined Molecular Dynamics/Quantum Chemistry and Polaron Model Study

The dynamics of pigment-pigment and pigment-protein interactions in light-harvesting complexes is studied with a novel approach which combines molecular dynamics (MD) simulations with quantum chemistry (QC) calculations. The MD simulations of an LH-II complex, solvated and embedded in a lipid bilayer at physiological conditions (with total system size of 87,055 atoms) revealed a pathway of a water molecule into the B800 binding site, as well as increased dimerization within the B850 BChl ring, as compared to the dimerization found for the crystal structure. The fluctuations of pigment (B850 BChl) excitation energies, as a function of time, were determined via ab initio QC calculations based on the geometries that emerged from the MD simulations. From the results of these calculations we constructed a time-dependent Hamiltonian of the B850 exciton system from which we determined the linear absorption spectrum. Finally, a polaron model is introduced to describe quantum mechanically both the excitonic and vibrational (phonon) degrees of freedom. The exciton-phonon coupling that enters into the polaron model, and the corresponding phonon spectral function are derived from the MD/QC simulations. It is demonstrated that, in the framework of the polaron model, the absorption spectrum of the B850 excitons can be calculated from the autocorrelation function of the excitation energies of individual BChls, which is readily available from the combined MD/QC simulations. The obtained result is in good agreement with the experimentally measured absorption spectrum.Comment: REVTeX3.1, 23 pages, 13 (EPS) figures included. A high quality PDF file of the paper is available at http://www.ks.uiuc.edu/Publications/Papers/PDF/DAMJ2001/DAMJ2001.pd

Laboratory colonization stabilizes the naturally dynamic microbiome composition of field collected Dermacentor andersoni ticks

Abstract Background Nearly a quarter of emerging infectious diseases identified in the last century are arthropod-borne. Although ticks and insects can carry pathogenic microorganisms, non-pathogenic microbes make up the majority of their microbial communities. The majority of tick microbiome research has had a focus on discovery and description; very few studies have analyzed the ecological context and functional responses of the bacterial microbiome of ticks. The goal of this analysis was to characterize the stability of the bacterial microbiome of Dermacentor andersoni ticks between generations and two populations within a species. Methods The bacterial microbiome of D. andersoni midguts and salivary glands was analyzed from populations collected at two different ecologically distinct sites by comparing field (F1) and lab-reared populations (F1-F3) over three generations. The microbiome composition of pooled and individual samples was analyzed by sequencing nearly full-length 16S rRNA gene amplicons using a Pacific Biosciences CCS platform that allows identification of bacteria to the species level. Findings In this study, we found that the D. andersoni microbiome was distinct in different geographic populations and was tissue specific, differing between the midgut and the salivary gland, over multiple generations. Additionally, our study showed that the microbiomes of laboratory-reared populations were not necessarily representative of their respective field populations. Furthermore, we demonstrated that the microbiome of a few individual ticks does not represent the microbiome composition at the population level. Conclusions We demonstrated that the bacterial microbiome of D. andersoni was complex over three generations and specific to tick tissue (midgut vs. salivary glands) as well as geographic location (Burns, Oregon vs. Lake Como, Montana vs. laboratory setting). These results provide evidence that habitat of the tick population is a vital component of the complexity of the bacterial microbiome of ticks, and that the microbiome of lab colonies may not allow for comparative analyses with field populations. A broader understanding of microbiome variation will be required if we are to employ manipulation of the microbiome as a method for interfering with acquisition and transmission of tick-borne pathogens

Detection of zoonotic bacterial pathogens in various hosts in the Mnisi community, Mpumalanga, South Africa using a microbiome sequencing approach

The Mnisi community, an agro pastoral area adjacent to the Kruger National Park, Mpumalanga Province, South Africa, is classified as one of South Africa's 14 rural poverty nodes. It is nestled at the cusp of a human-livestock-wildlife interface. In this area, undifferentiated non-malarial acute febrile illness (AFI) is among the most common presenting sign in patients seeking healthcare at the community clinics. Recent research suggested that zoonotic pathogens either rodent-borne or tick-borne may be common aetiologies of febrile illness in the community. The study had shown that patients presenting with non-malarial AFI had prior exposure to Bartonella spp., spotted fever group Rickettsia, Coxiella burnetti and Leptospira spp. Low levels of West Nile and Sindbis, but no Rift Valley fever virus exposure were found. In a separate study, partial 16S rRNA gene sequences closely related to the zoonotic tick-borne rickettsial pathogen Anaplasma phagocytophilum have been detected in domestic dogs in the area and R. africae was found in ticks collected from dogs. Research in the area has also found rodents to be common and abundant with 76% of households reporting that they have seen rodents around their homes; of which 62% saw them on a daily basis. The active surveillance for potential pathogens in febrile patients, wild rodents, domestic dogs and cattle is thus of utmost importance in order to identify emerging zoonotic pathogens which could impact human health and livestock production in the Mnisi area and beyond.Includes bibliographical referencesPoster presented at the 30th Meeting of the American Society for Rickettsiology (ASR), 2019Funding agencies: South African National Research Foundation (grants 92739, 110448 and 109350 to Marinda Oosthuizen), the University of Pretoria Institutional Research Theme on Animal and Zoonotic Diseases grant (awarded to Marinda Oosthuizen), and the Belgian Directorate General for Development Co-operation Framework. We thank Sonja Matthee (Stellenbosch University, South Africa) and Luis Neves (University of Pretoria) for expertise during the wild rodent trapping; Armanda Bastos (University of Pretoria) for molecular profiling of the rodents. The technical assistance of Derek Pouchnik and Mark Wildung of the Genomics Core at Washington State University is appreciated. The authors are grateful to Estelle Mayhew for the graphic design.ab202

The bacterial microbiome of Rhipicephalus sanguineus ticks in the Mnisi community, South Africa

Rhipicephalus sanguineus, the brown dog tick, is almost exclusively a parasite of domestic dogs and is well adapted to living with its canine host in kennels or human dwellings , where it may also bite people in the safety of their own homes. It is known to transmit various tick-borne diseases. In the Mnisi community, an area of high rural poverty in Bushbuckridge, Mpumalanga, South Africa, R. sanguineus is one of the most prevalent ticks found on dogs. The community lies at the human/livestock/wildlife interface where humans are at risk of infection with various tick-borne zoonotic diseases.Includes bibliographical referencesPoster presented at the 27th Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP2019)Funding agencies for research support: South African National Research Foundation (grants 92739, 110448 and 109350 to Marinda Oosthuizen), the University of Pretoria Institutional Research Theme on Animal and Zoonotic Diseases grant (awarded to Marinda Oosthuizen), and the Belgian Directorate General for Development Co-operation Framework. We thank the World Association for the Advancement of Veterinary Parasitology African Foundation (WAAVP AF) travel grant awarded to Rebecca Ackermann. The technical assistance of Derek Pouchnik and Mark Wildung of the Genomics Core at Washington State University is appreciated. The authors are grateful to Charles Byaruhanga for assistance with the statistical analyses and Estelle Mayhew for the graphic design.ab202

Bacterial blood microbiome of rodents captured from a human/livestock/wildlife interface in Bushbuckridge, South Africa

Zoonotic pathogens make up an important and increasing number of emerging and reemerging infectious diseases of humans worldwide. It has been documented that rodents serve as hosts and reservoirs of over 60 zoonotic pathogens that pose significant challenges to human health. The Mnisi community area in Bushbuckridge Municipality, Mpumalanga Province, South Africa is cradled in the heart of a human/livestock/wildlife interface. In this community humans, domestic animals and wildlife have perennial direct and indirect contact. Research in the area has found rodents to be common and abundant with 76% of households reported seeing rodents around their homes. Of that number 62% of the respondents saw them daily. A recent study in the area suggests that rodent-borne zoonoses may be implicated as causes of non-malarial acute febrile illness. In this study, 6.5% of acute febrile illness patients tested positive for the rodent-borne zoonotic pathogen Bartonella spp. on PCR, while 6.8% of patients showed prior exposure to Coxiella burnetti, the cause of Q fever and 2.3% to Leptospira spp. The surveillance of zoonotic pathogens in rodents in this community is thus of utmost importance as the role they play in the transmission of zoonotic pathogens to humans is unknown.Includes bibliographical referencesFunding agencies: Belgian Directorate General for Development Co-operation Framework (ITM/DGCD), and the South African National Research Foundation (grant 92739 to Marinda Oosthuizen). Prof Sonja Matthee (Stellenbosch University, South Africa) for providing expertise during the wild rodent trapping and Dr Armanda Bastos of the University of Pretoria for molecular identification of the rodents. Mark Wildung and Derek Pouchnik of the genomic sequencing core of the Washington State University, Pullman USA for technical assistance with Pacific Biosciences sequencing. The authors are grateful to Estelle Mayhew for the graphic design.ab202

Anaplasma phagocytophilum and Other Anaplasma spp. in Various Hosts in the Mnisi Community, Mpumalanga Province, South Africa

DNA samples from 74 patients with non-malarial acute febrile illness (AFI), 282 rodents, 100 cattle, 56 dogs and 160 Rhipicephalus sanguineus ticks were screened for the presence of Anaplasma phagocytophilum DNA using a quantitative PCR (qPCR) assay targeting the msp2 gene. The test detected both A. phagocytophilum and Anaplasma sp. SA/ZAM dog DNA. Microbiome sequencing confirmed the presence of low levels of A. phagocytophilum DNA in the blood of rodents, dogs and cattle, while high levels of A. platys and Anaplasma sp. SA/ZAM dog were detected in dogs. Directed sequencing of the 16S rRNA and gltA genes in selected samples revealed the presence of A. phagocytophilum DNA in humans, dogs and rodents and highlighted its importance as a possible contributing cause of AFI in South Africa. A number of recently described Anaplasma species and A. platys were also detected in the study. Phylogenetic analyses grouped Anaplasma sp. SA/ZAM dog into a distinct clade, with sufficient divergence from other Anaplasma species to warrant classification as a separate species. Until appropriate type-material can be deposited and the species is formally described, we will refer to this novel organism as Anaplasma sp. SA dog

Anaplasma phagocytophilum and other Anaplasma spp. in various hosts in the Mnisi Community, Mpumalanga Province, South Africa

DNA samples from 74 patients with non-malarial acute febrile illness (AFI), 282 rodents, 100 cattle, 56 dogs and 160 Rhipicephalus sanguineus ticks were screened for the presence of Anaplasma phagocytophilum DNA using a quantitative PCR (qPCR) assay targeting the msp2 gene. The test detected both A. phagocytophilum and Anaplasma sp. SA/ZAM dog DNA. Microbiome sequencing confirmed the presence of low levels of A. phagocytophilum DNA in the blood of rodents, dogs and cattle, while high levels of A. platys and Anaplasma sp. SA/ZAM dog were detected in dogs. Directed sequencing of the 16S rRNA and gltA genes in selected samples revealed the presence of A. phagocytophilum DNA in humans, dogs and rodents and highlighted its importance as a possible contributing cause of AFI in South Africa. A number of recently described Anaplasma species and A. platys were also detected in the study. Phylogenetic analyses grouped Anaplasma sp. SA/ZAM dog into a distinct clade, with sufficient divergence from other Anaplasma species to warrant classification as a separate species. Until appropriate type-material can be deposited and the species is formally described, we will refer to this novel organism as Anaplasma sp. SA dog.Supplementary Materials: Table S1: List of rodent species captured from the three habitat areas, Table S2: Origin and list of samples on which circular consensus sequencing (CCS) and multilocus gene sequencing were performed, Table S3: GenBank accession numbers of sequences used in the phylogenetic analysis of the Anaplasma species, Table S4: Sample information for the 16S rRNA, gltA, msp4 and ankA sequences generated in this study, Figure S1: Alignment of msp2 sequences from A. platys and A. phagocytophilum, Figure S2: Representative rarefaction curves from samples tested, Figure S3: Alignment of msp4 sequences from several species of Anaplasma, Figure S4: Alignment of ankA sequences from a few Anaplasma species showing the region that was amplified in this study.Belgian Directorate General for Development Co-operation Framework (ITM/DGCD), and the South African National Research Foundation.http://www.mdpi.com/journal/microorganismshj2021Medical VirologyVeterinary Tropical Disease