The evolution of intramitochondriality in Midichloria bacteria.

Midichloria spp. are intracellular bacterial symbionts of ticks. Representatives of this genus colonise mitochondria in the cells of their hosts. To shed light on this unique interaction we evaluated the presence of an intramitochondrial localization for three Midichloria in the respective tick host species and generated eight high-quality draft genomes and one closed genome, showing that this trait is non-monophyletic, either due to losses or multiple acquisitions. Comparative genomics supports the first hypothesis, as the genomes of non-mitochondrial symbionts are reduced subsets of those capable of colonising the organelles. We detect genomic signatures of mitochondrial tropism, including the differential presence of type IV secretion system and flagellum, which could allow the secretion of unique effectors and/or direct interaction with mitochondria. Other genes, including adhesion molecules, proteins involved in actin polymerisation, cell wall and outer membrane proteins, are only present in mitochondrial symbionts. The bacteria could use these to manipulate host structures, including mitochondrial membranes, to fuse with the organelles or manipulate the mitochondrial network.

Demographic and Clinical Presentations of Youth using Enhanced Mental Health Services in Six Indigenous Communities from the ACCESS Open Minds Network.

OBJECTIVE: In many Indigenous communities, youth mental health services are inadequate. Six Indigenous communities participating in the ACCESS Open Minds (AOM) network implemented strategies to transform their youth mental health services. This report documents the demographic and clinical presentations of youth accessing AOM services at these Indigenous sites. METHODS: Four First Nations and two Inuit communities contributed to this study. Youth presenting for mental health services responded to a customized sociodemographic questionnaire and presenting concerns checklist, and scales assessing distress, self-rated health and mental health, and suicidal thoughts and behaviors. RESULTS: Combined data from the First Nations sites indicated that youth across the range of 11-29 years accessed services. More girls/women than boys/men accessed services; 17% identified as LBGTQ+. Most (83%) youth indicated having access to at least one reliable adult and getting along well with the people living with them. Twenty-five percent of youth reported difficulty meeting basic expenses. Kessler (K10) distress scores indicated that half likely had a moderate mental health problem and a fourth had severe problems. Fifty-five percent of youth rated their mental health as fair or poor, while 50% reported suicidal thoughts in the last month. Anxiety, stress, depression and sleep issues were the most common presenting problems. Fifty-one percent of youth either accessed services themselves or were referred by family members. AOM was the first mental health service accessed that year for 68% of youth. CONCLUSIONS: This report is the first to present a demographic and clinical portrait of youth presenting at mental health services in multiple Indigenous settings in Canada. It illustrates the acceptability and feasibility of transforming youth mental health services using core principles tailored to meet communities' unique needs, resources, and cultures, and evaluating these using a common protocol. Data obtained can be valuable in evaluating services and guiding future service design. Trial registration name and number at Clinicaltrials.gov: ACCESS Open Minds/ACCESS Esprits ouverts, ISRCTN23349893.

Individualized Intervention to Support Mental Health Recovery Through Implementation of Digital Tools into Clinical Care: Feasibility Study.

Myriad digital tools exist to support mental health but there are multiple barriers to using these tools in routine care. This study aimed to assess the feasibility of an intervention incorporating a support role to help the clinical team identify and use technology to promote recovery. The technology specialist intervention is 3 months in duration and comprises four stages: goal setting, researching and evaluating tools, demonstrating and selecting tools, and ongoing support. We implemented the intervention in a community mental health center and a dual diagnosis treatment program, working with eight clients and their case managers. Clients and case managers willingly engaged with the technology specialist and found the intervention beneficial. Integration and collaboration with the care team facilitated implementation of the technology specialist in these real-world settings. Clients reported that the intervention made it easy to try a digital tool. Six of the eight participants stated that they made substantial progress toward their goals. The technology specialist is a promising new role for mental health care delivery to augment traditional services and enhance individualized recovery.

An Adapted Measure of Sibling Attachment: Factor Structure and Internal Consistency of the Sibling Attachment Inventory in Youth.

Parent-youth and peer relationship inventories based on attachment theory measure communication, trust, and alienation, yet sibling relationships have been overlooked. We developed the Sibling Attachment Inventory and evaluated its psychometric properties in a sample of 172 youth ages 10-14 years. We adapted the 25-item Sibling Attachment Inventory from the Inventory of Parent and Peer Attachment-Revised peer measure. Items loaded onto three factors, identified as communication, trust, and alienation, α = 0.93, 0.90, and 0.76, respectively. Sibling trust and alienation correlated with depression (r s = -0.33, r s = 0.48) and self-worth (r s = 0.23; r s = -0.32); sibling trust and alienation correlated with depression after controlling for parent trust and parent alienation (r s = -0.23, r s = 0.22). Preliminary analyses showed good internal consistency, construct validity, and incremental predictive validity. Following replication of these properties, this measure can facilitate large cohort assessments of sibling attachment.

The Recent Evolution of a Maternally-Inherited Endosymbiont of Ticks Led to the Emergence of the Q Fever Pathogen, Coxiella burnetii.

Q fever is a highly infectious disease with a worldwide distribution. Its causative agent, the intracellular bacterium Coxiella burnetii, infects a variety of vertebrate species, including humans. Its evolutionary origin remains almost entirely unknown and uncertainty persists regarding the identity and lifestyle of its ancestors. A few tick species were recently found to harbor maternally-inherited Coxiella-like organisms engaged in symbiotic interactions, but their relationships to the Q fever pathogen remain unclear. Here, we extensively sampled ticks, identifying new and atypical Coxiella strains from 40 of 58 examined species, and used this data to infer the evolutionary processes leading to the emergence of C. burnetii. Phylogenetic analyses of multi-locus typing and whole-genome sequencing data revealed that Coxiella-like organisms represent an ancient and monophyletic group allied to ticks. Remarkably, all known C. burnetii strains originate within this group and are the descendants of a Coxiella-like progenitor hosted by ticks. Using both colony-reared and field-collected gravid females, we further establish the presence of highly efficient maternal transmission of these Coxiella-like organisms in four examined tick species, a pattern coherent with an endosymbiotic lifestyle. Our laboratory culture assays also showed that these Coxiella-like organisms were not amenable to culture in the vertebrate cell environment, suggesting different metabolic requirements compared to C. burnetii. Altogether, this corpus of data demonstrates that C. burnetii recently evolved from an inherited symbiont of ticks which succeeded in infecting vertebrate cells, likely by the acquisition of novel virulence factors.

Evolutionary changes in symbiont community structure in ticks.

Ecological specialization to restricted diet niches is driven by obligate, and often maternally inherited, symbionts in many arthropod lineages. These heritable symbionts typically form evolutionarily stable associations with arthropods that can last for millions of years. Ticks were recently found to harbour such an obligate symbiont, Coxiella-LE, that synthesizes B vitamins and cofactors not obtained in sufficient quantities from blood diet. In this study, the examination of 81 tick species shows that some Coxiella-LE symbioses are evolutionarily stable with an ancient acquisition followed by codiversification as observed in ticks belonging to the Rhipicephalus genus. However, many other Coxiella-LE symbioses are characterized by low evolutionary stability with frequent host shifts and extinction events. Further examination revealed the presence of nine other genera of maternally inherited bacteria in ticks. Although these nine symbionts were primarily thought to be facultative, their distribution among tick species rather suggests that at least four may have independently replaced Coxiella-LE and likely represent alternative obligate symbionts. Phylogenetic evidence otherwise indicates that cocladogenesis is globally rare in these symbioses as most originate via horizontal transfer of an existing symbiont between unrelated tick species. As a result, the structure of these symbiont communities is not fixed and stable across the tick phylogeny. Most importantly, the symbiont communities commonly reach high levels of diversity with up to six unrelated maternally inherited bacteria coexisting within host species. We further conjecture that interactions among coexisting symbionts are pivotal drivers of community structure both among and within tick species.

Barriers to Employment for Transition-age Youth with Developmental and Psychiatric Disabilities.

Youth with developmental and psychiatric disabilities encounter significant vocational challenges, even when they receive supported employment services. We examined the barriers to employment for 280 transition-age youth with disabilities enrolled in supported employment in eight community rehabilitation centers. Employment team members identified each youth's top three barriers to employment using a 21-item checklist. Lack of work experience, transportation problems, and program engagement issues represented common barriers for both youth with developmental disabilities (53, 36, and 25%) and youth with psychiatric disabilities (20, 33, and 26%). Additional common barriers among youth with developmental disabilities included cognitive problems (32%) and lack of social skills (23%) and among youth with psychiatric disabilities included poor control of psychiatric symptoms (23%). Despite receiving evidence-based employment services, youth with disabilities encounter many barriers to employment. Awareness of typical barriers for transition-age youth, including those specific to different disability groups, may help employment programs anticipate challenges and develop strategies that avoid these barriers and their effects on employment opportunities.

Barriers and Facilitators to Sustainment of an Evidence-Based Supported Employment Program.

Large-scale initiatives to expand evidence-based practices are often poorly implemented and rarely endure. The purpose of this study was to identify the perceived barriers and facilitators to sustainment of an evidence-based supported employment program, Individual Placement and Support (IPS). Within a 2-year prospective study of sustainment among 129 IPS programs in 13 states participating in a national learning community, we interviewed IPS team leaders and coded their responses to semi-structured interviews using a conceptual framework adapted from another large-scale implementation study. Leaders in 122 agencies (95%) that sustained their IPS programs identified funding, prioritization, and workforce characteristics as both key facilitators and barriers. Additional key factors were lack of local community supports as a barrier and leadership and structured workflow as facilitators. Within the IPS learning community, team leaders attributed the sustainment of their program to funding, prioritization, workforce, agency leadership, and structured workflow. The actions of the learning community's leadership, state governments, and local programs together may have contributed to the high sustainment rate.

Planning Treatment and Assessing Recovery in Participants With Dual Diagnosis: Preliminary Evaluation of a New Clinical Tool.

OBJECTIVE: Integrated treatment for people with co-occurring mental illness and substance use disorder would be enhanced by a simple, recovery-oriented instrument to plan treatment and monitor progress toward dual recovery. This paper describes the development of a clinical instrument, the WestBridge Dual Recovery Inventory, and presents a preliminary evaluation of its usability. METHODS: In collaboration with participants in treatment, family members, clinicians, and program leaders, we developed an inventory on dual recovery and then examined its utility through a series of iterative steps. First, we tested the inventory for inter-rater reliability among 10 program participants (rated independently by the first and last author). Second, we examined concordance by having a separate group of 10 program participants and their care managers complete the inventory independently. Third, we observed 3 care managers and 10 participants working together to complete the inventory as part of routine care during the quarterly assessment; we evaluated shared decision making based on the process they used to resolve differences and on a brief survey completed by program participants as the end of the session. Finally, to measure the inventory's capacity to detect change over time, we analyzed the ratings from admission to one year for 43 participants with quarterly assessments available for that time period. RESULTS: The WestBridge Dual Recovery Inventory assesses 14 domains of recovery, each rated on 5-point scales. Inter-rater reliability was high (Kappa = .82 to 1.00); agreement between independent ratings by care managers and participants varied considerably (Kendall's tau = -.83 to +.87); and collaborative ratings demonstrated high scores on shared decision making. Participants improved significantly on 11 of 14 domains during the initial residential treatment phase (admission to six months) and sustained gains during outpatient assertive community treatment (6 to 12 months). CONCLUSIONS: This preliminary assessment of the WestBridge Dual Recovery Inventory suggests that it reliably assesses dual recovery, facilitates shared decision making, and captures changes over time. The inventory appears to be usable, well received by participants and care managers, specific for program goals, and sensitive to changes in the participants. Recovery measures may need to be program-specific.

The consequences of co-infections for parasite transmission in the mosquito Aedes aegypti.

Co-infections may modify parasite transmission opportunities directly as a consequence of interactions in the within-host environment, but also indirectly through changes in host life history. Furthermore, host and parasite traits are sensitive to the abiotic environment with variable consequences for parasite transmission in co-infections. We investigate how co-infection of the mosquito Aedes aegypti with two microsporidian parasites (Vavraia culicis and Edhazardia aedis) at two levels of larval food availability affects parasite transmission directly, and indirectly through effects on host traits. In a laboratory infection experiment, we compared how co-infection, at low and high larval food availability, affected the probability of infection, within-host growth and the transmission potential of each parasite, compared to single infections. Horizontal transmission was deemed possible for both parasites when infected hosts died harbouring horizontally transmitting spores. Vertical transmission was judged possible for E. aedis when infected females emerged as adults. We also compared the total input number of spores used to seed infections with output number, in single and co-infections for each parasite. The effects of co-infection on parasite fitness were complex, especially for V. culicis. In low larval food conditions, co-infection increased the chances of mosquitoes dying as larvae or pupae, thus increasing opportunities for V. culicis' horizontal transmission. However, co-infection reduced larval longevity and hence time available for V. culicis spore production. Overall, there was a negative net effect of co-infection on V. culicis, whereby the number of spores produced was less than the number used to seed infection. Co-infections also negatively affected horizontal transmission of the more virulent parasite, E. aedis, through reduced longevity of pre-adult hosts. However, its potential transmission suffered less relative to V. culicis. Our results show that co-infection can negatively affect parasite transmission opportunities, both directly as well as indirectly via effects on host life history. We also find that transmission is contingent on the combined effect of the abiotic environment.

Human brain tissue identification using coherent anti-Stokes Raman scattering spectroscopy and diffuse reflectance spectroscopy for deep brain stimulation surgery.

Significance: We assess the feasibility of using diffuse reflectance spectroscopy (DRS) and coherent anti-Stokes Raman scattering spectroscopy (CARS) as optical tools for human brain tissue identification during deep brain stimulation (DBS) lead insertion, thereby providing a promising avenue for additional real-time neurosurgical guidance. Aim: We developed a system that can acquire CARS and DRS spectra during the DBS surgery procedure to identify the tissue composition along the lead trajectory. Approach: DRS and CARS spectra were acquired using a custom-built optical probe integrated in a commercial DBS lead. The lead was inserted to target three specific regions in each of the brain hemispheres of a human cadaver. Spectra were acquired during the lead insertion at constant position increments. Spectra were analyzed to classify each spectrum as being from white matter (WM) or gray matter (GM). The results were compared with tissue classification performed on histological brain sections. Results: DRS and CARS spectra obtained using the optical probe can identify WM and GM during DBS lead insertion. The tissue composition along the trajectory toward a specific target is unique and can be differentiated by the optical probe. Moreover, the results obtained with principal component analysis suggest that DRS might be able to detect the presence of blood due to the strong optical absorption of hemoglobin. Conclusions: It is possible to use optical measurements from the DBS lead during surgery to identify WM and GM and possibly the presence of blood in human brain tissue. The proposed optical tool could inform the surgeon during the lead placement if the lead has reached the target as planned. Our tool could eventually replace microelectrode recordings, which would streamline the process and reduce surgery time. Further developments are required to fully integrate these tools into standard clinical procedures.

Specificity of resistance to dengue virus isolates is associated with genotypes of the mosquito antiviral gene Dicer-2.

In contrast to the prevailing view that invertebrate immunity relies on broad-spectrum recognition and effector mechanisms, intrinsic genetic compatibility between invertebrate hosts and their pathogens is often highly specific in nature. Solving this puzzle requires a better understanding of the molecular basis underlying observed patterns of invertebrate host-pathogen genetic specificity, broadly referred to as genotype-by-genotype interactions. Here, we identify an invertebrate immune gene in which natural polymorphism is associated with isolate-specific resistance to an RNA virus. Dicer-2 (dcr2) encodes a key protein upstream of the RNA interference (RNAi) pathway, a major antiviral component of innate immunity in invertebrates. We surveyed allelic polymorphism at the dcr2 locus in a wild-type outbred population and in three derived isofemale families of the mosquito Aedes aegypti that were experimentally exposed to several, genetically distinct isolates of dengue virus. We found that dcr2 genotype was associated with resistance to dengue virus in a virus isolate-specific manner. By contrast, no such association was found for genotypes at two control loci flanking dcr2, making it likely that dcr2 contains the yet-unidentified causal polymorphism(s). This result supports the idea that host-pathogen compatibility in this system depends, in part, on a genotype-by-genotype interaction between dcr2 and the viral genome, and points to the RNAi pathway as a potentially important determinant of intrinsic insect-virus genetic specificity.

Safe and valid? A systematic review of the psychometric properties of culturally adapted depression scales for use among Indigenous populations.

Background: Implementing culturally sensitive psychometric measures of depression may be an effective strategy to improve acceptance, response rate, and reliability of psychological assessment among Indigenous populations. However, the psychometric properties of depression scales after cultural adaptation remain unclear. Methods: We screened the Ovid Medline, PubMed, Embase, Global Health, PsycInfo, and CINAHL databases through three levels of search terms: Depression, Psychometrics, and Indigenous, following the PRISMA guidelines. We assessed metrics for reliability (including Cronbach's alpha), validity (including fit indices), and clinical utility (including predictive value). Results: Across 31 studies included the review, 13 different depression scales were adapted through language or content modification. Sample populations included Indigenous from the Americas, Asia, Africa, and Oceania. Most cultural adaptations had strong psychometric properties; however, few and inconsistent properties were reported. Where available, alphas, inter-rater and test-retest reliability, construct validity, and incremental validity often indicated increased cultural sensitivity of adapted scales. There were mixed results for clinical utility, criterion validity, cross-cultural validity, sensitivity, specificity, area under the receiver operating characteristic curve, predictive value, and likelihood ratio. Conclusions: Modifications to increase cultural relevance have the potential to improve fit and acceptance of a scale by the Indigenous population, however, these changes may decrease specificity and negative predictive value. There is an urgent need for suitable tools that are useful and reliable for identifying Indigenous individuals for clinical treatment of depression. This awaits future work for optimal specificity and validated cut-off points that take into account the high prevalence of depression in these populations.

The methods of improving cultural sensitivity of depression scales for use among global indigenous populations: a systematic scoping review.

Cultural adaptation of psychometric measures has become a process aimed at increasing acceptance, reliability, and validity among specific Indigenous populations. We present a systematic scoping review to: (1) identify the depression scales that have been culturally adapted for use among Indigenous populations worldwide, (2) globally report on the methods used in the cultural adaptation of those scales, and (3) describe the main features of those cultural adaptation methods. We included articles published from inception to April 2021, including 3 levels of search terms: Psychometrics, Indigenous, and Depression. The search was carried out in the Ovid Medline, PubMed, Embase, Global Health, PsycINFO, and CINAHL databases, following PRISMA guidelines. We identified 34 reports on processes of cultural adaptation that met the criteria. The scales were adapted for use among Indigenous populations from Africa, Australia, Asia, North America, and Latin America. The most common scales that underwent adaptation were the Patient Health Questionnaire (PHQ-9), the Center for Epidemiologic Studies Depression Scale (CES-D), and the Edinburgh Postnatal Depression Scale (EPDS). Methods of adaptation involved a revision of the measures' cultural appropriateness, standard/transcultural translation, revision of the administration process, and inclusion of visual supports. Culturally safe administration of scales was reported in some studies. To come to a consensus on most appropriate methods of improving cultural safety of psychometric measurement, most studies utilized qualitative methods or mixed methods to understand the specific community's needs. Revision of linguistic equivalence and cultural relevance of content, culturally safe administration procedures, qualitative methods, and participatory research were key features of developing safe culturally adapted measures for depressive symptoms among Indigenous populations. While for comparability, uniform scales would be ideal as mental health evaluations, an understanding of the cultural impact of measurements and local depression expressions would benefit the process of developing culturally sensitive psychometric scales. PROSPERO registration ID: CRD42023391439.

Exploring NUE in crops and in Arabidopsis ideotypes to improve yield and seed quality.

There is evidence that crop yields are showing a trend of stagnation in many countries. This review aims to make an inventory of the last decade's crop productions and the associated economic and environmental challenges. Manipulating nitrogen use efficiency in crops appears to be the best way to conciliate global food security, respecting environmental policies, and the need to produce biofuels. In such a context, the specifications of ideal plants for the future are discussed with regards to human needs and taking into account current physiological and genetic knowledge. The approaches undertaken so far to design an ideal crop and to find suitable new germplasms are discussed. The interest in using model plants in agronomic research is illustrated through the recent data provided by studies exploring natural variation in Arabidopsis thaliana. Efficient Arabidopsis ideotypes are proposed and discussed.

Tools and tutorial on practical ray tracing for microscopy.

Significance: An advanced understanding of optical design is necessary to create optimal systems but this is rarely taught as part of general curriculum. Compounded by the fact that professional optical design software tools have a prohibitive learning curve, this means that neither knowledge nor tools are easily accessible. Aim: In this tutorial, we introduce a raytracing module for Python, originally developed for teaching optics with ray matrices, to simplify the design and optimization of optical systems. Approach: This module is developed for ray matrix calculations in Python. Many important concepts of optical design that are often poorly understood such as apertures, aperture stops, and field stops are illustrated. Results: The module is explained with examples in real systems with collection efficiency, vignetting, and intensity profiles. Also, the optical invariant, an important benchmark property for optical systems, is used to characterize an optical system. Conclusions: This raytracing Python module will help improve the reader's understanding of optics and also help them design optimal systems.

Costs of insensitive acetylcholinesterase insecticide resistance for the malaria vector Anopheles gambiae homozygous for the G119S mutation.

BACKGROUND: The G119S mutation responsible for insensitive acetylcholinesterase resistance to organophosphate and carbamate insecticides has recently been reported from natural populations of Anopheles gambiae in West Africa. These reports suggest there are costs of resistance associated with this mutation for An. gambiae, especially for homozygous individuals, and these costs could be influential in determining the frequency of carbamate resistance in these populations. METHODS: Life-history traits of the AcerKis and Kisumu strains of An. gambiae were compared following the manipulation of larval food availability in three separate experiments conducted in an insecticide-free laboratory environment. These two strains share the same genetic background, but differ in being homozygous for the presence or absence of the G119S mutation at the ace-1 locus, respectively. RESULTS: Pupae of the resistant strain were significantly more likely to die during pupation than those of the susceptible strain. Ages at pupation were significantly earlier for the resistant strain and their dry starved weights were significantly lighter; this difference in weight remained when the two strains were matched for ages at pupation. CONCLUSIONS: The main cost of resistance found for An. gambiae mosquitoes homozygous for the G119S mutation was that they were significantly more likely to die during pupation than their susceptible counterparts, and they did so across a range of larval food conditions. Comparing the frequency of G119S in fourth instar larvae and adults emerging from the same populations would provide a way to test whether this cost of resistance is being expressed in natural populations of An. gambiae and influencing the dynamics of this resistance mutation.

Parental contributions to child anxiety sensitivity: a review and recommendations for future directions.

Anxiety sensitivity (AS) is defined as the fear of anxiety-related symptoms (e.g., a fast beating heart) and the consequences that may follow from these symptoms (e.g., a heart attack). Recently, child AS has been examined in relation to parental AS and parental anxiety to elucidate potential parental contributions. Given inconsistent findings to date, this review was intended to identify parental factors that are significant contributors to child AS. Two key findings from this review included the absence of a significant relationship between parental anxiety and child AS and the determination that the parent-child AS association is conditional upon the child reporter, the parent reporter, and the specific dimensions of AS being tested. Recommendations for future directions include examining specific facets of AS, studying parental contributions amongst anxiety-disordered youth, and employing sufficiently large samples to allow for between child group comparisons.

Reliability and Feasibility of the First-Episode Psychosis Services Fidelity Scale-Revised for Remote Assessment.

OBJECTIVE: The authors sought to evaluate the interrater reliability and feasibility of the First-Episode Psychosis Services Fidelity Scale-Revised (FEPS-FS-R) for remote assessment of first-episode psychosis programs according to the coordinated specialty care model. METHODS: The authors used the FEPS-FS-R to assess the fidelity of 36 first-episode psychosis program sites in the United States with information from three sources: administrative data, health record review, and phone interviews with staff. Four raters independently conducted fidelity assessments of five program sites by listening to each of the staff interviews and independently rating the two other data sources from each site. To calculate interrater reliability, the authors used intraclass correlation coefficients (ICCs) for each of the five sites and across the total scores for each site. RESULTS: Total interrater reliability was in the good to excellent range, with a mean ICC of 0.91 (95% confidence interval = 0.72-0.99, p<0.001). Two first-episode psychosis program sites (6%) achieved excellent fidelity, 25 (69%) good fidelity, and nine (25%) fair fidelity. Of the 32 distinct items on the FEPS-FS-R, 23 (72%) were used with good or excellent fidelity. Most sites achieved high fidelity on most items, but five items received ratings indicating low-fidelity use at most sites. The fidelity assessment proved feasible, and sites required on average 10.5 hours for preparing and conducting the fidelity review. CONCLUSIONS: The FEPS-FS-R has high interrater reliability and can differentiate high-, moderate-, and low-fidelity sites. Most sites had good overall fidelity, but the FEPS-FS-R identified some services that were challenging to implement at many sites.

A novel Borrelia species, intermediate between Lyme disease and relapsing fever groups, in neotropical passerine-associated ticks.

Lyme disease (LD) and relapsing fevers (RF) are vector-borne diseases caused by bacteria of the Borrelia genus. Here, we report on the widespread infection by a non-described Borrelia species in passerine-associated ticks in tropical rainforests of French Guiana, South America. This novel Borrelia species is common in two tick species, Amblyomma longirostre and A. geayi, which feed on a broad variety of neotropical mammal and bird species, including migratory species moving to North America. The novel Borrelia species is divergent from the LD and RF species, and is more closely related to the reptile- and echidna-associated Borrelia group that was recently described. Genome sequencing showed that this novel Borrelia sp. has a relatively small genome consisting of a 0.9-Mb-large chromosome and an additional 0.3 Mb dispersed on plasmids. It harbors an RF-like genomic organization but with a unique mixture of LD- and RF-specific genes, including genes used by RF Borrelia for the multiphasic antigen-switching system and a number of immune-reactive protein genes used for the diagnosis of LD. Overall, our data indicate that this novel Borrelia is an intermediate taxon between the LD and RF species that may impact a large host spectrum, including American mammals. The designation "Candidatus Borrelia mahuryensis" is proposed for this species.