The SAFE Model: State Authenticity as a Function of Three Types of Fit.

The SAFE model asserts that state authenticity stems from three types of fit to the environment. Across two studies of university students, we validated instruments measuring self-concept, goal, and social fit as unique predictors of state authenticity. In Study 1 (N = 969), relationships between fit and state authenticity were robust to controlling for conceptually similar and distinct variables. Using experience sampling methodology, Study 2 (N = 269) provided evidence that fit and authenticity co-vary at the state (i.e., within-person) level, controlling for between-person effects. Momentary variation in each fit type predicted greater state authenticity, willingness to return to the situation, and state attachment to one's university. Each fit type was also predicted by distinct contextual features (e.g., location, activity, company). Supporting a theorized link to cognitive fluency, situations eliciting self-concept fit elicited higher working memory capacity and lower emotional burnout. We discuss the implications of fit in educational contexts.

The lay of the land: Associations between environmental features and personality.

OBJECTIVE: Personality traits cluster across countries, regions, cities, and neighborhoods. What drives the formation of these clusters? Ecological theory suggests that physical locations shape humans' patterns of behaviors and psychological characteristics. Based on this theory, we examined whether and how differential land-cover relates to individual personality. METHOD: We followed a preregistered three-pronged analysis approach to investigate the associations between personality (N = 2,690,878) and land-cover across the United States. We used eleven land-cover categories to classify landscapes and tested their association with personality against broad physical and socioeconomic factors. RESULTS: Urban areas were positively associated with openness to experience and negatively associated with conscientiousness. Coastal areas were positively associated with openness to experience and neuroticism but negatively associated with agreeableness and conscientiousness. Cultivated areas were negatively associated with openness. Landscapes at the periphery of human activity, such as shrubs, bare lands, or permanent snows, were not reliably associated with personality traits. CONCLUSIONS: Bivariate correlations, multilevel, and random forest models uncovered robust associations between landscapes and personality traits. These findings align with ecological theory suggesting that an individual's environment contributes to their behaviors, thoughts, and feelings.

Functional characterization of a TerC family protein of Riemerella anatipestifer in manganese detoxification and virulence.

Manganese (Mn) is an essential element for bacteria, but the overload of manganese is toxic. In a previous study, we showed that the cation diffusion facilitator protein MetA and the resistance-nodulation-division efflux pump MetB are responsible for Mn efflux in the bacterial pathogen Riemerella anatipestifer CH-1. However, whether this bacterium encodes additional manganese efflux proteins is unclear. In this study, we show that R. anatipestifer CH-1 encodes a tellurium resistance C (TerC) family protein with low similarity to other characterized TerC family proteins. Compared to the wild type (WT), the terC mutant of R. anatipestifer CH-1 (∆terC) is sensitive to Mn(II) intoxication. The ability of TerC to export manganese is higher than that of MetB but lower than that of MetA. Consistently, terC deletion (∆terC) led to intracellular accumulation of Mn2+ under excess manganese conditions. Further study showed that ∆terC was more sensitive than the WT to the oxidant hypoclorite but not to hydrogen peroxide. Mutagenesis studies showed that the mutant at amino acid sites of Glu116 (E116), Asp122 (D122), Glu245 (E245) Asp248 (D248), and Asp254 (D254) may be involved in the ability of TerC to export manganese. The transcription of terC was upregulated under excess manganese and downregulated under iron-limited conditions. However, this was not dependent on the manganese metabolism regulator MetR. In contrast to a strain lacking the manganese efflux pump MetA or MetB, the terC mutant is attenuated in virulence in a duckling model of infection due to increased sensitivity to duck serum. Finally, comparative analysis showed that homologs of TerC are distributed across the bacterial kingdom, suggesting that TerC exerts a conserved manganese efflux function.IMPORTANCERiemerella anatipestifer is a notorious bacterial pathogen of ducks and other birds. In R. anatipestifer, the genes involved in manganese efflux have not been completely identified, although MetA and MetB have been identified as two manganese exporters. Additionally, the function of TerC family proteins in manganese efflux is controversial. Here, we demonstrated that a TerC family protein helps prevent Mn(II) intoxication in R. anatipestifer and that the ability of TerC to export manganese is intermediate compared to that of MetA and MetB. Sequence analysis and mutagenesis studies showed that the conserved key amino sites of TerC are Glu116, Asp122, Glu245, Asp248, and Asp254. The transcription of terC was regulated by manganese excess and iron limitation. Finally, we show that TerC plays a role in the virulence of R. anatipestifer due to the increased sensitivity to duck serum, rather than the increased sensitivity to manganese. Taken together, these results expand our understanding of manganese efflux and the pathogenic mechanisms of R. anatipestifer.

The Misinformation Susceptibility Test (MIST): A psychometrically validated measure of news veracity discernment.

Interest in the psychology of misinformation has exploded in recent years. Despite ample research, to date there is no validated framework to measure misinformation susceptibility. Therefore, we introduce Verification done, a nuanced interpretation schema and assessment tool that simultaneously considers Veracity discernment, and its distinct, measurable abilities (real/fake news detection), and biases (distrust/naïvité-negative/positive judgment bias). We then conduct three studies with seven independent samples (Ntotal = 8504) to show how to develop, validate, and apply the Misinformation Susceptibility Test (MIST). In Study 1 (N = 409) we use a neural network language model to generate items, and use three psychometric methods-factor analysis, item response theory, and exploratory graph analysis-to create the MIST-20 (20 items; completion time < 2 minutes), the MIST-16 (16 items; < 2 minutes), and the MIST-8 (8 items; < 1 minute). In Study 2 (N = 7674) we confirm the internal and predictive validity of the MIST in five national quota samples (US, UK), across 2 years, from three different sampling platforms-Respondi, CloudResearch, and Prolific. We also explore the MIST's nomological net and generate age-, region-, and country-specific norm tables. In Study 3 (N = 421) we demonstrate how the MIST-in conjunction with Verification done-can provide novel insights on existing psychological interventions, thereby advancing theory development. Finally, we outline the versatile implementations of the MIST as a screening tool, covariate, and intervention evaluation framework. As all methods are transparently reported and detailed, this work will allow other researchers to create similar scales or adapt them for any population of interest.

Functional characterization of two TolC in the resistance to drugs and metals and in the virulence of Riemerella anatipestifer.

IMPORTANCE: Riemerella anatipestifer (RA) is a notorious duck pathogen, characterized by a multitude of serotypes that exhibit no cross-reaction with one another. Moreover, RA is resistant to various antibacterial agents. Consequently, understanding the mechanisms behind resistance and identifying potential targets for drug development have become pressing needs. In this study, we show that the two TolC proteins play a role in the resistance to different drugs and metals and in the virulence. The results suggest that TolCA has a wider range of efflux substrates than TolCB. Except for gentamicin, neither TolCA nor TolCB was involved in the efflux of the other tested antibiotics. Strikingly, TolCA but not TolCB enhanced the frequency of resistance-conferring mutations. Moreover, TolCA was involved in RA virulence. Given its conservation in RA, TolCA has potential as a drug target for the development of therapeutics against RA infections.

Adhesion of vessel wall to stentriever during combined technique for mechanical thrombectomy in acute ischemic stroke: A histomorphological study.

PURPOSE: Detection of vessel wall tissue in thrombus material in patients with ischemic stroke is judged as vascular injury. So far, several studies investigated components of the free clots after mechanical thrombectomy. The aim of this retrospective study was to investigate the involvement and role of the stentriever in vessel wall injury by analysis of the composition of adherent tissue to the stentriever during combined aspiration thrombectomy with stentriever. METHODS: Stentriever with adherent tissue and free clots in aspiration samples from patients undergoing mechanical thrombectomy (aspiration plus stentriever) were separately assessed for the occurrence of parts of vascular tissue together with clinical and interventional data as well as clinical outcome data. Specimens were analyzed histomorphologically and immunohistochemically. Findings, focused on parts of vessel wall were reported together with clinical data. RESULTS: Specimens from 21 identified patients were available. Parts of the vessel wall were detected in 7 out 21 (33%) samples. All specimens revealed fresh thrombus material without signs of organization or atheromatous tissue. In 90% of patients mTICI was greater than 2b without signs of secondary vessel injury. No vascular tissue was found in free clots of the aspiration samples. CONCLUSION: The examination of adherent tissue to the stentriever instead of the examination of free clots may affect the number of detected parts of vessel wall. Further studies in combination with vessel wall imaging may elucidate the origin of remnants of vessel wall.

Early clinical experience with the new generation Pipeline Vantage flow diverter in the treatment of unruptured saccular aneurysms using short-term dual antiplatelet therapy.

PURPOSE: The Pipeline Vantage flow diverter with Shield technology (PV) used in this study is a 4th-generation flow diverter (FD) designed to reduce thrombogenicity, promote endothelialization of the implant and increase efficiency in achieving aneurysm closure. In this study, we report the aneurysm occlusion rate, complication rate and clinical outcome with short-term dual antiplatelet therapy (DAPT) in the treatment of unruptured intracranial saccular aneurysms using the PV. METHODS: We retrospectively identified patients treated between September 2021 and January 2023 with the PV and subsequently underwent short-term DAPT for 3 months. Patient and aneurysm characteristics, peri- and post-procedural complications, clinical outcomes and the grade of aneurysm occlusion were documented. RESULTS: Thirty patients with 32 aneurysms were treated. Successful FD implantation was achieved in all cases (100%). No periprocedural complications were documented. The overall symptomatic complication rate was 10% and the neurologic, treatment-related symptomatic complication rate was 6.6%. Only one symptomatic complication (3.3%) was device-related. Permanent clinical deterioration occurred in 2/30 patients (6.6%), leading to deterioration of the mRS within the first 3 months after treatment. No mortality was documented. The rate of complete aneurysm occlusion after 3 months and after a mean imaging follow-up of 9.9 months was 65.6% and 75%, respectively. CONCLUSION: Implantation of the PV for the treatment of saccular intracranial aneurysms achieves a good aneurysm occlusion rate with a low rate of complications. In addition, the use of short-term DAPT after PV implantation appears to be safe.

ecolo-zip: A global, rich and granular characterization of biogeophysical ecology for 1.5 million postal codes.

The inescapable fact that human life is perpetually embedded in a tangible biogeophysical environment - and the consequences that this has for individuals and societies - have long fascinated scholars of all backgrounds. Technological progress and the advent of big data have spurred ever-more precise attempts to quantify our biogeophysical environments. However, many such datasets lack spatial granularity, global coverage, content depth, or accessibility. Here, we introduce ecolo-zip, a novel geospatial dataset that provides a granular-yet-global, parsimonious-yet-rich ecological characterization of over 1.5 million postal codes across 94 countries and regions. Combining two large-scale satellite image resources (ASTER; SRTM, ICC = 0.999) and a customized geospatial sampling model, we provide high-resolution indicators of physical topography (elevation, mountainousness, distance to sea), vegetation (normalized difference vegetation index), and climate (surface temperature). With this resource - featuring methodological details, visualizations, and application suggestions - we hope to contribute towards understanding the multi-faceted interactions between humans and their environments.

Insulin Can Delay Neutrophil Extracellular Trap Formation In Vitro-Implication for Diabetic Wound Care?

Diabetes is a worldwide evolving disease with many associated complications, one of which is delayed or impaired wound healing. Appropriate wound healing strongly relies on the inflammatory reaction directly after injury, which is often altered in diabetic wound healing. After an injury, neutrophils are the first cells to enter the wound site. They have a special defense mechanism, neutrophil extracellular traps (NETs), consisting of released DNA coated with antimicrobial proteins and histones. Despite being a powerful weapon against pathogens, NETs were shown to contribute to impaired wound healing in diabetic mice and are associated with amputations in diabetic foot ulcer patients. The anti-diabetic drugs metformin and liraglutide have already been shown to regulate NET formation. In this study, the effect of insulin was investigated. NET formation after stimulation with PMA (phorbol myristate acetate), LPS (lipopolysaccharide), or calcium ionophore (CI) in the presence/absence of insulin was analyzed. Insulin led to a robust delay of LPS- and PMA-induced NET formation but had no effect on CI-induced NET formation. Mechanistically, insulin induced reactive oxygen species, phosphorylated p38, and ERK, but reduced citrullination of histone H3. Instead, bacterial killing was induced. Insulin might therefore be a new tool for the regulation of NET formation during diabetic wound healing, either in a systemic or topical application.

BLASTphylo: An Interactive Web Tool for Taxonomic and Phylogenetic Analysis of Prokaryotic Genes.

Identifying a protein's function is crucial to reveal its role in the cellular complex. Computationally, the most common approach is to search for homologous proteins in a large database of proteins of known function using BLAST. One goal of such an analysis is the identification and visualization of the protein in the taxonomy of interest. Another goal is the reconstruction of the phylogenetic history of the protein. However, the BLAST result provides information about the occurrence of the protein in the taxonomy and its putative function mainly in a tabular format. This requires manual interventions and makes the taxonomic identification laborious. Although various tools exist to visualize and annotate large-scale trees, none of them intuitively and interactively visualizes the protein's occurrence in the taxonomy for different taxonomic ranks. To target this gap, we developed BLASTphylo, a web tool that combines BLAST with automatic taxonomic mapping and phylogenetic analysis and provides the results in interactive visualizations. We demonstrate the functionalities of BLASTphylo in two case studies.

In vitro and in vivo comparative analysis of antibacterial activity of green-synthesized silver nanoparticles.

This study aims to compare antibacterial effects of green-synthesized silver nanoparticles (AgNPs) with silver nitrate (AgNO3 ). AgNPs were successfully synthesized using Eucalyptus camaldulensis leaf extract as a reducing and stabilizing agent. Minimum inhibitory concentrations (MIC) of AgNPs and AgNO3 against Staphylococcus aureus and Pseudomonas aeruginosa ranged between 4.8 and 6.75 µg mL-1 . Growth curves demonstrated that inhibition of P. aeruginosa occurred right after AgNPs were added and throughout the period of the study (72 h). Antibacterial effects of both AgNPs and AgNO3 could be abrogated by cysteine and 2-mercaptoethanol, thiol-containing compounds. Galleria mellonella model revealed relatively low toxic effects of both AgNPs and AgNO3 . At 20MIC of AgNPs (≈137.8 mg kg-1 ), more than 80% survival of G. mellonella was observed. Unexpectedly, silver-containing agents could not rescue larvae after S. aureus infection. Further ex vivo experiments in the presence of coelomic larval fluid demonstrated the reduction of antibacterial activity of both AgNPs and AgNO3 . It was speculated that anionic molecules present in the coelomic fluid might neutralize the action of Ag ions. Binding of AgNPs or AgNO3 to albumin, a major protein in human blood which transport several endogenous compounds was not detected, indicating that the silver-containing agents could be applied as an antimicrobial agent.

Profiling of branched chain and straight chain saturated fatty acids by ultra-high performance liquid chromatography-mass spectrometry.

Branched chain fatty acids (BCFAs) are one of the important sub categories of fatty acids (FAs) which have unique functions in nature. They are commonly analyzed by GC-MS after derivatization to methyl esters (FAMEs). On the other hand, there is a lack of isomer-selective LC-MS methods which allow the distinction of different isomers with wide coverage of carbon chain length. In this work, a systematic retention and isomer selectivity study on seven commercially available UHPLC columns (six polysaccharide columns Chiralpak IA-U, IB-U, IC-U, ID-U, IG-U and IH-U; one Acquity UPLC CSH C18 column) was performed. Various experimental factors were evaluated including column temperatures, gradient profiles and flow rates to elucidate their effects on the separation ability of homologous series of BCFAs with distinct chain lengths, different branching types and branching positions. In general, IG-U outperformed the other columns in terms of isomer selectivity especially for the short and medium-chain BCFA isomers while RP C18 showed good potential in terms of selectivity for long-chain BCFA isomers. Furthermore, after the evaluation of the chromatographic retention pattern on the various columns and method optimization, we report a methodology for untargeted isomer-selective BCFA profiling without precolumn derivatization with UHPLC-ESI-MS/MS by quadrupole-time-of-flight instrument with SWATH acquisition. The best method provides selectivity for constitutional isomers of BCFAs covering distinct chain length (C5-C20) with different branching types (methyl or ethyl) and branching positions (2Me, 3Me, 4Me, 6Me, anteiso and iso-BCFAs) with an optimized LC condition on Acquity UPLC CSH C18 column. Finally, the optimized method was applied for the BCFAs profiling in lipid extracts of Staphylococcus aureus samples. Besides, pooled human platelets and pooled human plasma were evaluated as mammalian samples for presence of BCFAs as well. The new method showed strong potential for BCFA profiling in bacterial samples including different isomers anteiso and iso-BCFAs, which could be a useful tool for related subdisciplines in metabolomics and lipidomics in particular in combination with electron-activated dissociation MS. Compared to GC, the presented isomer selective LC methods can be also of great utility for preparative purposes. Equivalent (carbon) chain length numbers were calculated for RP18 and Chiralpak IG-U and compared to those of FAMEs obtained by GC.

From an Hsp90 - binding protein to a peptide drug.

The Lpl proteins represent a class of lipoproteins that was first described in the opportunistic bacterial pathogen Staphylococcus aureus, where they contribute to pathogenicity by enhancing F-actin levels of host epithelial cells and thereby increasing S. aureus internalization. The model Lpl protein, Lpl1 was shown to interact with the human heat shock proteins Hsp90α and Hsp90ß, suggesting that this interaction may trigger all observed activities. Here we synthesized Lpl1-derived peptides of different lengths and identified two overlapping peptides, namely, L13 and L15, which interacted with Hsp90α. Unlike Lpl1, the two peptides not only decreased F-actin levels and S. aureus internalization in epithelial cells but they also decreased phagocytosis by human CD14+ monocytes. The well-known Hsp90 inhibitor, geldanamycin, showed a similar effect. The peptides not only interacted directly with Hsp90α, but also with the mother protein Lpl1. While L15 and L13 significantly decreased lethality of S. aureus bacteremia in an insect model, geldanamycin did not. In a mouse bacteremia model L15 was found to significantly decreased weight loss and lethality. Although the molecular bases of the L15 effect is still elusive, in vitro data indicate that simultaneous treatment of host immune cells with L15 or L13 and S. aureus significantly increase IL-6 production. L15 and L13 represent not antibiotics but they cause a significant reduction in virulence of multidrug-resistant S. aureus strains in in vivo models. In this capacity, they can be an important drug alone or additive with other agents.

Openness buffers the impact of Belief in Conspiracy Theories on COVID-19 vaccine hesitancy: Evidence from a large, representative Italian sample.

As COVID-19 continues to incur enormous personal and societal costs, widespread vaccination against the virus remains the most effective strategy to end the pandemic. However, vaccine hesitancy is rampant and has been steadily rising for decades. Seeking to remedy this, personality psychologists have begun to explore psychological drivers of vaccine hesitancy, including the Big Five. Openness to Experience presents itself as a vexing case as previous attempts to study its association with vaccine hesitancy have yielded mixed findings. In this preregistered study, we hypothesise that the impact of Openness to Experience on Vaccine Hesitancy depends on its interplay with other factors, namely conspiracy beliefs. To test this, we apply logistic regressions, simple slopes analyses, and propensity score matching to a nationally representative sample of 2500 Italian citizens, collected in May 2021. Contrary to our original hypothesis (i.e., Openness will have a positive association with Vaccine Hesitancy at high - and a negative at low - levels of Conspiracy Beliefs) we find that high Openness diminishes the impact of Belief in Conspiracy Theories on Vaccine Hesitancy. Consistent with previous research, we propose that Openness serves as a buffer against extreme positions by allowing individuals to be exposed to a greater diversity of information.

Role of the NaHCO3 Transporter MpsABC in the NaHCO3-ß-Lactam-Responsive Phenotype in Methicillin-Resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) infections are an increasing concern due to their intrinsic resistance to most standard-of-care ß-lactam antibiotics. Recent studies of clinical isolates have documented a novel phenotype, termed NaHCO3 responsiveness, in which a substantial proportion of MRSA strains exhibit enhanced susceptibility to ß-lactams such as cefazolin and oxacillin in the presence of NaHCO3. A bicarbonate transporter, MpsAB (membrane potential-generating system), was recently found in S. aureus, where it plays a role in concentrating NaHCO3 for anaplerotic pathways. Here, we investigated the role of MpsAB in mediating the NaHCO3 responsiveness phenotype. Radiolabeled NaH14CO3 uptake profiling revealed significantly higher accumulation in NaHCO3-responsive vs nonresponsive MRSA strains when grown in ambient air. In contrast, under 5% CO2 conditions, NaHCO3-responsive (but not nonresponsive) strains exhibited repressed uptake. Oxacillin MICs were measured in four prototype strains and their mpsABC deletion mutants in the presence of NaHCO3 supplementation under 5% CO2 conditions. NaHCO3-mediated reductions in oxacillin MICs were observed in the responsive parental strains but not in mpsABC deletion mutants. No significant impact on oxacillin MICs was observed in the nonresponsive strains under the same conditions. Transcriptional and translational studies were carried out using both quantitative reverse transcription-PCR (qRT-PCR) and mpsA-green fluorescent protein (GFP) fusion constructs; these investigations showed that mpsA expression and translation were significantly upregulated during mid-exponential-phase growth in oxacillin-NaHCO3-supplemented medium in responsive versus nonresponsive strains. Taken together, these data show that the NaHCO3 transporter MpsABC is a key contributor to the NaHCO3-ß-lactam responsiveness phenotype in MRSA. IMPORTANCE MRSA infections are increasingly difficult to treat, due in part to their resistance to most ß-lactam antibiotics. A novel and relatively common phenotype, termed NaHCO3 responsiveness, has been identified in which MRSA strains show increased susceptibility in vitro and in vivo to ß-lactams in the presence of NaHCO3. A recently described S. aureus NaHCO3 transporter, MpsAB, is involved in intracellular NaHCO3 concentration for anaplerotic pathways. We investigated the role of MpsAB in mediating the NaHCO3 responsiveness phenotype in four prototype MRSA strains (two responsive and two nonresponsive). We demonstrated that MpsABC is an important contributor to the NaHCO3-ß-lactam responsiveness phenotype. Our study adds to the growing body of well-defined characteristics of this novel phenotype, which could potentially translate to alternative targets for MRSA treatment using ß-lactams.

Greed communication predicts the approval and reach of US senators' tweets.

Social media are at the forefront of modern political campaigning. They allow politicians to communicate directly with constituents and constituents to endorse politicians' messages and share them with their networks. Analyzing every tweet of all US senators holding office from 2013 to 2021 (861,104 tweets from 140 senators), we identify a psycholinguistic factor, greed communication, that robustly predicts increased approval (favorites) and reach (retweets). These effects persist when tested against diverse established psycholinguistic predictors of political content dissemination on social media and various other psycholinguistic variables. We further find that greed communication in the tweets of Democratic senators is associated with greater approval and retweeting compared to greed communication in the tweets of Republican senators, especially when those tweets also mention political outgroups.

Biology and Regulation of Staphylococcal Biofilm.

Despite continuing progress in medical and surgical procedures, staphylococci remain the major Gram-positive bacterial pathogens that cause a wide spectrum of diseases, especially in patients requiring the utilization of indwelling catheters and prosthetic devices implanted temporarily or for prolonged periods of time. Within the genus, if Staphylococcus aureus and S. epidermidis are prevalent species responsible for infections, several coagulase-negative species which are normal components of our microflora also constitute opportunistic pathogens that are able to infect patients. In such a clinical context, staphylococci producing biofilms show an increased resistance to antimicrobials and host immune defenses. Although the biochemical composition of the biofilm matrix has been extensively studied, the regulation of biofilm formation and the factors contributing to its stability and release are currently still being discovered. This review presents and discusses the composition and some regulation elements of biofilm development and describes its clinical importance. Finally, we summarize the numerous and various recent studies that address attempts to destroy an already-formed biofilm within the clinical context as a potential therapeutic strategy to avoid the removal of infected implant material, a critical event for patient convenience and health care costs.

Identification of a serotonin N-acetyltransferase from Staphylococcus pseudintermedius ED99.

Serotonin N-acetyltransferase (SNAT) catalyzes the biosynthesis of N-acetylserotonin (NAS) and N-acetyltryptamine (NAT), two pleiotropic molecules with neurotransmitter functions. Here, we report the identification of a SNAT protein in the genus Staphylococcus. The SNAT gene identified in Staphylococcus pseudintermedius ED99, namely SPSE_0802, encodes a 140 residues-long cytoplasmic protein. The recombinant protein SPSE_0802 was expressed in E. coli BL21 and found to acetylate serotonin (SER) and tryptamine (TRY) as well as other trace amines in vitro. The production of the neuromodulators NAS and NAT was detected in the cultures of different members of the genus Staphylococcus and the role of SPSE_0802 in this production was confirmed in an ED99 SPSE_0802 deletion mutant. A search for SNAT homologues showed that the enzyme is widely distributed across the genus which correlated with the SNAT activity detected in 22 out of the 40 Staphylococcus strains tested. The N-acetylated products of SNAT are precursors for melatonin synthesis and are known to act as neurotransmitters and activate melatonin receptors, among others, inducing various responses in the human body. The identification of SNAT in staphylococci could contribute to a better understanding of the interaction between those human colonizers and the host peripheral nervous system.