Recombinational exchange of M-fibril and T-pilus genes generates extensive cell surface diversity in the global group A Streptococcus population.

Among genes present in all group A streptococci (GAS), those encoding M-fibril and T-pilus proteins display the highest levels of sequence diversity, giving rise to the two primary serological typing schemes historically used to define strain. A new genotyping scheme for the pilin adhesin and backbone genes is developed and, when combined with emm typing, provides an account of the global GAS strain population. Cluster analysis based on nucleotide sequence similarity assigns most T-serotypes to discrete pilin backbone sequence clusters, yet the established T-types correspond to only half the clusters. The major pilin adhesin and backbone sequence clusters yield 98 unique combinations, defined as "pilin types." Numerous horizontal transfer events that involve pilin or emm genes generate extensive antigenic and functional diversity on the bacterial cell surface and lead to the emergence of new strains. Inferred pilin genotypes applied to a meta-analysis of global population-based collections of pharyngitis and impetigo isolates reveal highly significant associations between pilin genotypes and GAS infection at distinct ecological niches, consistent with a role for pilin gene products in adaptive evolution. Integration of emm and pilin typing into open-access online tools (pubmlst.org) ensures broad utility for end-users wanting to determine the architecture of M-fibril and T-pilus genes from genome assemblies.IMPORTANCEPrecision in defining the variant forms of infectious agents is critical to understanding their population biology and the epidemiology of associated diseases. Group A Streptococcus (GAS) is a global pathogen that causes a wide range of diseases and displays a highly diverse cell surface due to the antigenic heterogeneity of M-fibril and T-pilus proteins which also act as virulence factors of varied functions. emm genotyping is well-established and highly utilized, but there is no counterpart for pilin genes. A global GAS collection provides the basis for a comprehensive pilin typing scheme, and online tools for determining emm and pilin genotypes are developed. Application of these tools reveals the expansion of structural-functional diversity among GAS via horizontal gene transfer, as evidenced by unique combinations of surface protein genes. Pilin and emm genotype correlations with superficial throat vs skin infection provide new insights on the molecular determinants underlying key ecological and epidemiological trends.

Inter-species gene flow drives ongoing evolution of Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis.

Streptococcus dysgalactiae subsp. equisimilis (SDSE) is an emerging cause of human infection with invasive disease incidence and clinical manifestations comparable to the closely related species, Streptococcus pyogenes. Through systematic genomic analyses of 501 disseminated SDSE strains, we demonstrate extensive overlap between the genomes of SDSE and S. pyogenes. More than 75% of core genes are shared between the two species with one third demonstrating evidence of cross-species recombination. Twenty-five percent of mobile genetic element (MGE) clusters and 16 of 55 SDSE MGE insertion regions were shared across species. Assessing potential cross-protection from leading S. pyogenes vaccine candidates on SDSE, 12/34 preclinical vaccine antigen genes were shown to be present in >99% of isolates of both species. Relevant to possible vaccine evasion, six vaccine candidate genes demonstrated evidence of inter-species recombination. These findings demonstrate previously unappreciated levels of genomic overlap between these closely related pathogens with implications for streptococcal pathobiology, disease surveillance and prevention.

Adaptation of sequential action benefits from timing variability related to lateral basal ganglia circuitry.

Streamlined action sequences must remain flexible should stable contingencies in the environment change. By combining analyses of behavioral structure with a circuit-specific manipulation in mice, we report on a relationship between action timing variability and successful adaptation that relates to post-synaptic targets of primary motor cortical (M1) projections to dorsolateral striatum (DLS). In a two-lever instrumental task, mice formed successful action sequences by, first, establishing action scaffolds and, second, smoothly extending action duration to adapt to increased task requirements. Interruption of DLS neurons in M1 projection territories altered this process, evoking higher-rate actions that were more stereotyped in their timing, reducing opportunities for success. Based on evidence from neuronal tracing experiments, we propose that DLS neurons in M1 projection territories supply action timing variability to facilitate adaptation, a function that may involve additional downstream subcortical processing relating to collateralization of descending motor pathways to multiple basal ganglia centers.

What Role Does Striatal Dopamine Play in Goal-directed Action?

Evidence suggests that dopamine activity provides a US-related prediction error for Pavlovian conditioning and the reinforcement signal supporting the acquisition of habits. However, its role in goal-directed action is less clear. There are currently few studies that have assessed dopamine release as animals acquire and perform self-paced instrumental actions. Here we briefly review the literature documenting the psychological, behavioral and neural bases of goal-directed actions in rats and mice, before turning to describe recent studies investigating the role of dopamine in instrumental learning and performance. Plasticity in dorsomedial striatum, a central node in the network supporting goal-directed action, clearly requires dopamine release, the timing of which, relative to cortical and thalamic inputs, determines the degree and form of that plasticity. Beyond this, bilateral release appears to reflect reward prediction errors as animals experience the consequences of an action. Such signals feedforward to update the value of the specific action associated with that outcome during subsequent performance, with dopamine release at the time of action reflecting the updated predicted action value. More recently, evidence has also emerged for a hemispherically lateralised signal associated with the action; dopamine release is greater in the hemisphere contralateral to the spatial target of the action. This effect emerges over the course of acquisition and appears to reflect the strength of the action-outcome association. Thus, during goal-directed action, dopamine release signals the action, the outcome and their association to shape the learning and performance processes necessary to support this form of behavioral control.

Cell-free DNA methylation analysis as a marker of malignancy in pleural fluid.

Diagnosis of malignant pleural effusion (MPE) is made by cytological examination of pleural fluid or histological examination of pleural tissue from biopsy. Unfortunately, detection of malignancy using cytology has an overall sensitivity of 50%, and is dependent upon tumor load, volume of fluid assessed, and cytopathologist experience. The diagnostic yield of pleural fluid cytology is also compromised by low abundance of tumor cells or when morphology is obscured by inflammation or reactive mesothelial cells. A reliable molecular marker that may complement fluid cytology for the diagnosis of malignant pleural effusion is needed. The purpose of this study was to establish a molecular diagnostic approach based on pleural effusion cell-free DNA methylation analysis for the differential diagnosis of malignant pleural effusion and benign pleural effusion. This was a blind, prospective case-control biomarker study. We recruited 104 patients with pleural effusion for the study. We collected pleural fluid from patients with: MPE (n = 48), indeterminate pleural effusion in subjects with known malignancy or IPE (n = 28), and benign PE (n = 28), and performed the Sentinel-MPE liquid biopsy assay. The methylation level of Sentinel-MPE was markedly higher in the MPE samples compared to BPE control samples (p < 0.0001) and the same tendency was observed relative to IPE (p = 0.004). We also noted that the methylation signal was significantly higher in IPE relative to BPE (p < 0.001). We also assessed the diagnostic efficiency of the Sentinel-MPE test by performing receiver operating characteristic analysis (ROC). For the ROC analysis we combined the malignant and indeterminate pleural effusion groups (n = 76) and compared against the benign group (n = 28). The detection sensitivity and specificity of the Sentinel-MPE test was high (AUC = 0.912). The Sentinel-MPE appears to have better performance characteristics than cytology analysis. However, combining Sentinel-MPE with cytology analysis could be an even more effective approach for the diagnosis of MPE. The Sentinel-MPE test can discriminate between BPE and MPE. The Sentinel-MPE liquid biopsy test can detect aberrant DNA in several different tumor types. The Sentinel-MPE test can be a complementary tool to cytology in the diagnosis of MPE.

Variation in pneumococcal invasiveness metrics is driven by serotype carriage duration and initial risk of disease.

Streptococcus pneumoniae is an opportunistic pathogen that, while usually carried asymptomatically, can cause severe invasive diseases like meningitis and bacteremic pneumonia. A central goal in S. pneumoniae public health management is to identify which serotypes (immunologically distinct strains) pose the most risk of invasive disease. The most common invasiveness metrics use cross-sectional data (i.e., invasive odds ratios (IOR)), or longitudinal data (i.e., attack rates (AR)). To assess the reliability of these metrics we developed an epidemiological model of carriage and invasive disease. Our mathematical analyses illustrate qualitative failures with the IOR metric (e.g., IOR can decline with increasing invasiveness parameters). Fitting the model to both longitudinal and cross-sectional data, our analysis supports previous work indicating that invasion risk is maximal at or near time of colonization. This pattern of early invasive disease risk leads to substantial (up to 5-fold) biases when estimating underlying differences in invasiveness from IOR metrics, due to the impact of carriage duration on IOR. Together, these results raise serious concerns with the IOR metric as a basis for public health decision-making and lend support for multiple alternate metrics including AR.

Cell-Free DNA Methylation Analysis as a Marker of Malignancy in Pleural Fluid.

Background: Diagnosis of malignant pleural effusion (MPE) is made by cytological examination of pleural fluid or histological examination of pleural tissue from biopsy. Unfortunately, detection of malignancy using cytology has an overall sensitivity of 50%, and is dependent upon tumor load, volume of fluid assessed, and cytopathologist experience. The diagnostic yield of pleural fluid cytology is also compromised by low abundance of tumor cells or when morphology is obscured by inflammation or reactive mesothelial cells. A reliable molecular marker that may complement fluid cytology malignant pleural effusion diagnosis is needed. The purpose of this study was to establish a molecular diagnostic approach based on pleural effusion cell-free DNA methylation analysis for the differential diagnosis of malignant pleural effusion and benign pleural effusion. Results: This was a blind, prospective case-control biomarker study. We recruited 104 patients with pleural effusion for the study. We collected pleural fluid from patients with: MPE (n = 48), PPE (n = 28), and benign PE (n = 28), and performed the Sentinel-MPE liquid biopsy assay. The methylation level of Sentinel-MPE was markedly higher in the MPE samples compared to BPE control samples (p < 0.0001) and the same tendency was observed relative to PPE (p = 0.004). We also noted that the methylation signal was significantly higher in PPE relative to BPE (p < 0.001). We also assessed the diagnostic efficiency of the Sentinel-MPE test by performing receiver operating characteristic analysis (ROC). For the ROC analysis we combined the malignant and paramalignant groups (n = 76) and compared against the benign group (n = 28). The detection sensitivity and specificity of the Sentinel-MPE test was high (AUC = 0.912). The Sentinel-MPE appears to have better performance characteristics than cytology analysis. However, combining Sentinel-MPE with cytology analysis could be an even more effective approach for the diagnosis of MPE. Conclusions: The Sentinel-MPE test can discriminate between BPE and MPE. The Sentinel-MPE liquid biopsy test can detect aberrant DNA in several different tumor types. The Sentinel-MPE test can be a complementary tool to cytology in the diagnosis of MPE.

The Motivational Determinants of Human Action, Their Neural Bases and Functional Impact in Adolescents With Obsessive-Compulsive Disorder.

Background: Establishing the motivational influences on human action is essential for understanding choice and decision making in health and disease. Here we used tests of value-based decision making, manipulating both predicted and experienced reward values to assess the motivational control of goal-directed action in healthy adolescents and those with obsessive-compulsive disorder (OCD). Methods: After instrumental training on a two action-two outcome probabilistic task, adolescents (n = 21) underwent Pavlovian conditioning using distinct stimuli predicting either the instrumental outcomes, a third outcome, or nothing. We then assessed functional magnetic resonance imaging during choice tests in which we varied the predicted value, using specific and general Pavlovian-instrumental transfer, and the experienced value, using outcome devaluation. To establish functional significance, we tested a matched cohort of adolescents with OCD (n = 20). Results: In healthy adolescents, both predicted and experienced values influenced the performance of goal-directed actions, mediated by distinct orbitofrontal-striatal circuits involving the lateral orbitofrontal cortex (OFC) and medial OFC, respectively. However, in adolescents with OCD, choice was insensitive to changes in either predicted or experienced values. These impairments were related to hypoactivity in the lateral OFC and hyperactivity in the medial OFC during specific Pavlovian-instrumental transfer and hypoactivity in the anterior prefrontal cortex, caudate nucleus, and their connectivity in the devaluation test. Conclusions: We found that predicted and experienced values exerted a potent influence on the performance of goal-directed actions in adolescents via distinct orbitofrontal- and prefrontal-striatal circuits. Furthermore, the influence of these motivational processes was severely blunted in OCD, as was the functional segregation of circuits involving medial and lateral OFC, producing dysregulated action control.

Scaling artificial light at night and disease vector interactions into socio-ecological systems: a conceptual appraisal.

There is burgeoning interest in how artificial light at night (ALAN) interacts with disease vectors, particularly mosquitoes. ALAN can alter mosquito behaviour and biting propensity, and so must alter disease transfer rates. However, most studies to date have been laboratory-based, and it remains unclear how ALAN modulates disease vector risk. Here, we identify five priorities to assess how artificial light can influence disease vectors in socio-ecological systems. These are to (i) clarify the mechanistic role of artificial light on mosquitoes, (ii) determine how ALAN interacts with other drivers of global change to influence vector disease dynamics across species, (iii) determine how ALAN interacts with other vector suppression strategies, (iv) measure and quantify the impact of ALAN at scales relevant for vectors, and (v) overcome the political and social barriers in implementing it as a novel vector suppression strategy. These priorities must be addressed to evaluate the costs and benefits of employing appropriate ALAN regimes in complex socio-ecological systems if it is to reduce disease burdens, especially in the developing world. This article is part of the theme issue 'Light pollution in complex ecological systems'.

Immp2l knockdown in male mice increases stimulus-driven instrumental behaviour but does not alter goal-directed learning or neuron density in cortico-striatal circuits in a model of Tourette syndrome and autism spectrum disorder.

Cortico-striatal neurocircuits mediate goal-directed and habitual actions which are necessary for adaptive behaviour. It has recently been proposed that some of the core symptoms of autism spectrum disorder (ASD) and Gilles de la Tourette syndrome (GTS), such as tics and other repetitive behaviours, may emerge because of imbalances in these neurocircuits. We have recently developed a model of ASD and GTS by knocking down Immp2l, a mitochondrial gene frequently associated with these disorders. The current study sought to determine whether Immp2l knockdown (KD) in male mice alters flexible, goal- or cue- driven behaviour using procedures specifically designed to examine response-outcome and stimulus-response associations, which underlie goal-directed and habitual behaviour, respectively. Whether Immp2l KD alters neuron density in cortico-striatal neurocircuits known to regulate these behaviours was also examined. Immp2l KD mice and wild type-like mice (WT) were trained on Pavlovian and instrumental learning procedures where auditory cues predicted food delivery and lever-press responses earned a food outcome. It was demonstrated that goal-directed learning was not changed for Immp2l KD mice compared to WT mice, as lever-press responses were sensitive to changes in the value of the food outcome, and to contingency reversal and degradation. There was also no difference in the capacity of KD mice to form habitual behaviours compared to WT mice following extending training of the instrumental action. However, Immp2l KD mice were more responsive to auditory stimuli paired with food as indicated by a non-specific increase in lever response rates during Pavlovian-to-instrumental transfer. Finally, there were no alterations to neuron density in striatum or any prefrontal cortex or limbic brain structures examined. Thus, the current study suggests that Immp2l is not necessary for learned maladaptive goal or stimulus driven behaviours in ASD or GTS, but that it may contribute to increased capacity for external stimuli to drive behaviour. Alterations to stimulus-driven behaviour could potentially influence the expression of tics and repetitive behaviours, suggesting that genetic alterations to Immp2l may contribute to these core symptoms in ASD and GTS. Given that this is the first application of this battery of instrumental learning procedures to a mouse model of ASD or GTS, it is an important initial step in determining the contribution of known risk-genes to goal-directed versus habitual behaviours, which should be more broadly applied to other rodent models of ASD and GTS in the future.

Need for shared internal mound conditions by fungus-growing Macrotermes does not predict their species distributions, in current or future climates.

The large, iconic nests constructed by social species are engineered to create internal conditions buffered from external climatic extremes, to allow reproduction and/or food production. Nest-inhabiting eusocial Macrotermitinae (Blattodea: Isoptera) are outstanding palaeo-tropical ecosystem engineers that evolved fungus-growing to break down plant matter ca 62 Mya; the termites feed on the fungus and plant matter. Fungus-growing ensures a constant food supply, but the fungi need temperature-buffered, high humidity conditions, created in architecturally complex, often tall, nest-structures (mounds). Given the need for constant and similar internal nest conditions by fungi farmed by different Macrotermes species, we assessed whether current distributions of six African Macrotermes correlate with similar variables, and whether this would reflect in expected species' distribution shifts with climate change. The primary variables explaining species' distributions were not the same for the different species. Distributionally, three of the six species are predicted to see declines in highly suitable climate. For two species, range increases should be small (less than 9%), and for a single species, M. vitrialatus, 'very suitable' climate could increase by 64%. Mismatches in vegetation requirements and anthropogenic habitat transformation may preclude range expansion, however, presaging disruption to ecosystem patterns and processes that will cascade through systems at both landscape and continental scales. This article is part of the theme issue 'The evolutionary ecology of nests: a cross-taxon approach'.

Cognitive effects of thalamostriatal degeneration are ameliorated by normalizing striatal cholinergic activity.

The loss of neurons in parafascicular thalamus (Pf) and their inputs to dorsomedial striatum (DMS) in Lewy body disease (LBD) and Parkinson's disease dementia (PDD) have been linked to the effects of neuroinflammation. We found that, in rats, these inputs were necessary for both the function of striatal cholinergic interneurons (CINs) and the flexible encoding of the action-outcome (AO) associations necessary for goal-directed action, producing a burst-pause pattern of CIN firing but only during the remapping elicited by a shift in AO contingency. Neuroinflammation in the Pf abolished these changes in CIN activity and goal-directed control after the shift in contingency. However, both effects were rescued by either the peripheral or the intra-DMS administration of selegiline, a monoamine oxidase B inhibitor that we found also enhances adenosine triphosphatase activity in CINs. These findings suggest a potential treatment for the cognitive deficits associated with neuroinflammation affecting the function of the Pf and related structures.

Opportunities and barriers to translating the hibernation phenotype for neurocritical care.

Targeted temperature management (TTM) is standard of care for neonatal hypoxic ischemic encephalopathy (HIE). Prevention of fever, not excluding cooling core body temperature to 33°C, is standard of care for brain injury post cardiac arrest. Although TTM is beneficial, HIE and cardiac arrest still carry significant risk of death and severe disability. Mammalian hibernation is a gold standard of neuroprotective metabolic suppression, that if better understood might make TTM more accessible, improve efficacy of TTM and identify adjunctive therapies to protect and regenerate neurons after hypoxic ischemia brain injury. Hibernating species tolerate cerebral ischemia/reperfusion better than humans and better than other models of cerebral ischemia tolerance. Such tolerance limits risk of transitions into and out of hibernation torpor and suggests that a barrier to translate hibernation torpor may be human vulnerability to these transitions. At the same time, understanding how hibernating mammals protect their brains is an opportunity to identify adjunctive therapies for TTM. Here we summarize what is known about the hemodynamics of hibernation and how the hibernating brain resists injury to identify opportunities to translate these mechanisms for neurocritical care.

Goal-Directed Action Is Initially Impaired in a hAPP-J20 Mouse Model of Alzheimer's Disease.

Cognitive-behavioral testing in preclinical models of Alzheimer's disease has failed to capture deficits in goal-directed action control. Here, we provide the first comprehensive investigation of goal-directed action in a transgenic mouse model of Alzheimer's disease. Specifically, we tested outcome devaluation performance in male and female human amyloid precursor protein (hAPP)-J20 mice. Mice were first trained to press left and right levers for pellet and sucrose outcomes, respectively (counterbalanced), over 4 d. On test, mice were prefed one of the outcomes to satiety and given a choice between levers. Devaluation performance was intact for 36-week-old wild-types of both sexes, who responded more on the valued relative to the devalued lever (Valued > Devalued). By contrast, devaluation was impaired (Valued = Devalued) for J20 mice of both sexes, and for 52-week-old male mice regardless of genotype. After additional lever press training (i.e., 8-d lever pressing in total), devaluation was intact for all mice, demonstrating that the initial deficits were not a result of a nonspecific impairment in reward processing, depression, or locomotor activity in J20 or aging mice. Follow-up analyses revealed that microglial expression in the dorsal CA1 region of the hippocampus was associated with poorer outcome devaluation performance on initial, but not later tests. Together, these data demonstrate that goal-directed action is initially impaired in J20 mice of both sexes and in aging male mice regardless of genotype, and that this impairment is related to neuroinflammation in the dorsal CA1 hippocampal region.

What does dopamine release reveal about latent inhibition?

A recent paper by Kutlu et al. (2022) argues that changes in dopamine release during stimulus pre-exposure reflect non-associative changes in attention to the conditioned stimulus that are causally related to latent inhibition effects. Associative accounts of pre-exposure-induced changes in associability suggest, however, that such conclusions may be premature.

Covid-19 and child criminal exploitation in the UK: implications of the pandemic for county lines.

In March 2020, the UK was placed in lockdown following the spread of the Covid-19 virus. Just as legitimate workplaces made changes to enable their employees to work from home, the illicit drugs trade also made alternative arrangements, adapting its supply models to ensure continuity of operations. Based upon qualitative interviews with 46 practitioners, this paper assesses how front-line professionals have experienced and perceived the impact of Covid-19 on child criminal exploitation and County Lines drug supply in the UK. Throughout the paper, we highlight perceived adaptations to the County Lines supply model, the impact of lockdown restrictions on detection and law enforcement activities aimed at County Lines, and on efforts to safeguard children and young people from criminal exploitation. Our participants generally believed that the pandemic had induced shifts to County Lines that reflected an ongoing evolution of the drug supply model and changes in understanding or attention because of Covid-19 restrictions, rather than a complete reconstitution of the model itself. Practitioners perceived that Covid-19 has had, and continues to have, a significant impact on some young people's vulnerability to exploitation, on the way in which police and frontline practitioners respond to County Lines and child criminal exploitation, and on the way illegal drugs are being moved and sold.

Phytotherapy in Diabetic Foot Ulcers: A Promising Strategy for Effective Wound Healing.

Despite the advancement in wound care, the effective therapy of chronic diabetic ulcers continues to be a challenge. Wound healing is a highly controlled process, which involves a sequence of complex overlapping steps. This healing pathway comprises of hemostasis, inflammation, proliferative, and remodeling phases. Recent evidence suggests that phytomedicines can prevent or repair different kinds of destructive cellular damage, including chronic wounds. Several phytochemicals such as polyphenols, alkaloids, flavonoids, terpenoids, and glycosides have pleiotropic effects, including stimulation of fibroblast proliferation, the main step in wound healing. Besides, the mechanism involves induction of collagen synthesis, migration, and reepithelization and their antimicrobial, antioxidant, anti-inflammatory, and immunomodulatory actions. Similarly, the use of phytochemicals alone or as an adjuvant with standard therapy has demonstrated promising results in managing complications in the diabetic foot. For instance, the extract of Carica papaya has been shown antioxidant, antimicrobial, and anti-inflammatory, and immunomodulatory effects, which, together with proteolytic enzymatic activity, contributes to its wound healing property. It is generally believed that phytotherapy has no or minimal toxicity than synthetic therapeutic agents, favoring its use in diabetic foot ulcer management. The current review highlights the selected phytochemicals and their sources; and potential application in diabetic foot ulcer management.Key teaching points and nutritional relevanceCurrently, phytochemicals have been shown wide potential in disease. management including alleviating clinical manifestations, preventing degenerative disease, and curing illness.Increased evidence of phytochemical as anti-infective and anti-inflammatory suggests its role in the management of diabetic foot ulcer(DFU).Potential benefit along with minimal adverse effect favors its application as adjuvant therapy.Further research is needed to standardize its dose and formulation to enhance its clinical application in DFU management.