Identification of a short sequence motif in the influenza A virus pathogenicity factor PB1-F2 required for inhibition of human NLRP3.

Influenza A virus infection activates the NLRP3 inflammasome, a multiprotein signaling complex responsible for the proteolytic activation and release of the proinflammatory cytokine IL-1ß from monocytes and macrophages. Some influenza A virus (IAV) strains encode a short 90-amino acid peptide (PB1-F2) on an alternative open reading frame of segment 2, with immunomodulatory activity. We recently demonstrated that contemporary IAV PB1-F2 inhibits the activation of NLRP3, potentially by NEK7-dependent activation. PB1-F2 binds to NLRP3 with its C-terminal 50 amino acids, but the exact binding motif was unknown. On the NLRP3 side, the interface is formed through the leucine-rich-repeat (LRR) domain, potentially in conjunction with the pyrin domain. Here, we took advantage of PB1-F2 sequences from IAV strains with either weak or strong NLRP3 interaction. Sequence comparison and structure prediction using Alphafold2 identified a short four amino acid sequence motif (TQGS) in PB1-F2 that defines NLRP3-LRR binding. Conversion of this motif to that of the non-binding PB1-F2 suffices to lose inhibition of NLRP3 dependent IL-1ß release. The TQGS motif further alters the subcellular localization of PB1-F2 and its colocalization with NLRP3 LRR and pyrin domain. Structural predictions suggest the establishment of additional hydrogen bonds between the C-terminus of PB1-F2 and the LRR domain of NLRP3, with two hydrogen bonds connecting to threonine and glutamine of the TQGS motif. Phylogenetic data show that the identified NLRP3 interaction motif in PB1-F2 is widely conserved among recent IAV-infecting humans. Our data explain at a molecular level the specificity of NLRP3 inhibition by influenza A virus. IMPORTANCE: Influenza A virus infection is accompanied by a strong inflammatory response and high fever. The human immune system facilitates the swift clearance of the virus with this response. An essential signal protein in the proinflammatory host response is IL-1b. It is released from inflammatory macrophages, and its production and secretion depend on the function of NLRP3. We had previously shown that influenza A virus blocks NLRP3 activation by the expression of a viral inhibitor, PB1-F2. Here, we demonstrate how this short peptide binds to NLRP3 and provide evidence that a four amino acid stretch in PB1-F2 is necessary and sufficient to mediate this binding. Our data identify a new virus-host interface required to block one signaling path of the innate host response against influenza A virus.

Regional spread of an atypical ESBL-producing Escherichia coli ST131H89 clone among different human and environmental reservoirs in Western Switzerland.

We describe the inter-regional spread of a novel ESBL-producing Escherichia coli subclone (ST131H89) in long-term care facility residents, general population, and environmental water sources in Western Switzerland between 2017 and 2020. The study highlights the importance of molecular surveillance for tracking emerging antibiotic-resistant pathogens in healthcare and community settings.

Insights of undergraduate health sciences students about a French interprofessional training initiative.

BACKGROUND: Incorporating interprofessional collaboration within healthcare is critical to delivery of patient-centered care. Interprofessional Education (IPE) programs are key to promoting such collaboration. The 'Public Health Service' (PHS) in France is a mandatory IPE initiative that embodies this collaborative spirit, bringing together students from varied health undergraduate training programs-nursing, physiotherapy, pharmacy, midwifery, and medicine- in a common training program focused on primary prevention. The aim of the study was to assess the experience and attitudes of students in the five health training programs regarding the interest of IPEs in the PHS. METHODS: A cross-sectional survey was administered to 823 students from the 2022-2023 cohort at a French university. The questionnaire was designed with 12 Likert-scale questions specifically created to evaluate the students' experiences, knowledge, and attitudes focused on IPE during the practical seminars, school interventions, and the overall PHS. Additionally, an open-ended question was utilized to gather qualitative data. Statistical analyses assessed satisfaction levels across undergraduate training programs, while thematic analysis was applied to the qualitative responses. RESULTS: Within the surveyed cohort, 344 students responded to the survey. The findings showed that students were satisfied with the interprofessional collaboration, both in practical teaching sessions (75% satisfaction) and in primary prevention projects conducted in schools (70% satisfaction), despite their having faced challenges with coordination. Pharmacy students, in particular, highlighted the need for adjustments in program scheduling. The qualitative feedback underscored the positive value of IPE, notwithstanding the organizational difficulties stemming from different academic timetables. CONCLUSION: The student feedback indicated a high level of satisfaction with the interprofessional work carried out in both the practical teaching and the primary prevention projects. To further enhance the educational impact and address the scheduling complexities, it is recommended that program refinements be made based on student feedback and pedagogical best practices.

A multifaceted small RNA modulates gene expression upon glucose limitation in Staphylococcus aureus.

Pathogenic bacteria must rapidly adapt to ever-changing environmental signals resulting in metabolism remodeling. The carbon catabolite repression, mediated by the catabolite control protein A (CcpA), is used to express genes involved in utilization and metabolism of the preferred carbon source. Here, we have identified RsaI as a CcpA-repressed small non-coding RNA that is inhibited by high glucose concentrations. When glucose is consumed, RsaI represses translation initiation of mRNAs encoding a permease of glucose uptake and the FN3K enzyme that protects proteins against damage caused by high glucose concentrations. RsaI also binds to the 3' untranslated region of icaR mRNA encoding the transcriptional repressor of exopolysaccharide production and to sRNAs induced by the uptake of glucose-6 phosphate or nitric oxide. Furthermore, RsaI expression is accompanied by a decreased transcription of genes involved in carbon catabolism pathway and an activation of genes involved in energy production, fermentation, and nitric oxide detoxification. This multifaceted RNA can be considered as a metabolic signature when glucose becomes scarce and growth is arrested.

Extent of Low-density Lipoprotein Cholesterol Reduction and All-cause and Cardiovascular Mortality Benefit: A Systematic Review and Meta-analysis.

ABSTRACT: Lipid-modifying agents steadily lower low-density lipoprotein cholesterol (LDL-C) levels with the aim of reducing mortality. A systematic review and meta-analysis were conducted to determine whether all-cause or cardiovascular (CV) mortality effect size for lipid-lowering therapy varied according to the magnitude of LDL-C reduction. Electronic databases were searched, including PubMed and ClinicalTrials.gov , from inception to December 31, 2019. Eligible studies included randomized controlled trials that compared lipid-modifying agents (statins, ezetimibe, and PCSK-9 inhibitors) versus placebo, standard or usual care or intensive versus less-intensive LDL-C-lowering therapy in adults, with or without known history of CV disease with a follow-up of at least 52 weeks. All-cause and CV mortality as primary end points, myocardial infarction, stroke, and non-CV death as secondary end points. Absolute risk differences [ARD (ARDs) expressed as incident events per 1000 person-years], number needed to treat (NNT), and rate ratios (RR) were assessed. Sixty randomized controlled trials totaling 323,950 participants were included. Compared with placebo, usual care or less-intensive therapy, active or more potent lipid-lowering therapy reduced the risk of all-cause death [ARD -1.33 (-1.89 to -0.76); NNT 754 (529-1309); RR 0.92 (0.89-0.96)]. Intensive LDL-C percent lowering was not associated with further reductions in all-cause mortality [ARD -0.27 (-1.24 to 0.71); RR 1.00 (0.94-1.06)]. Intensive LDL-C percent lowering did not further reduce CV mortality [ARD -0.28 (-0.83 to 0.38); RR 1.02 (0.94-1.09)]. Our findings indicate that risk reduction varies across subgroups and that overall NNTs are high. Identifying patient subgroups who benefit the most from LDL-C levels reduction is clinically relevant and necessary.

Infectious disease hotlines to provide advice to general practitioners: a prospective study.

BACKGROUND: Telephone hotlines in infectious diseases (ID) are part of antimicrobial stewardship programs designed to provide support and expertise in ID and to control antibiotic resistance. The aim of the study was to characterize the activity of the ID hotlines and estimate their usefulness for general practitioners (GPs). METHODS: This was a multicenter prospective observational study in different French regions. ID teams involved in antimicrobial stewardship with a hotline for GPs were asked to record their advice from April 2019 to June 2022. In these regions, all GPs were informed of the ID hotline's operating procedures. The main outcome was usage rate of the hotlines by GPs. RESULTS: Ten volunteer ID teams collected 4138 requests for advice from 2171 GPs. The proportion of GPs using the hotline varied pronouncedly by region, from 54% in the Isere department, to less than 1% in departments with the lowest usage. These differences were associated with the number of physicians in ID teams and with the age of the hotline. These results highlighted the value of working time as a means of ensuring the permanence of expertise. The main reasons for calling were: a diagnostic question (44%); choice of antibiotic (31%). The ID specialist provided advice on antibiotic therapy (43%) or a proposal for specialized consultation or hospitalization (11%). CONCLUSIONS: ID hotlines could help to strengthen cooperation between primary care and hospital medicine. However, the deployment and perpetuation of this activity require reflection concerning its institutional and financial support.

Comparative genomics analysis of two Helcococcus kunzii strains co-isolated with Staphylococcus aureus from diabetic foot ulcers.

Helcococcus kunzii is a commensal Gram-positive bacterial species recovered from the human skin microbiota and considered as an opportunistic pathogen. Although little is known about its clinical significance, its increased abundance has been reported in infected wounds, particularly in foot ulcers in persons with diabetes. This species is usually detected in mixed cultures from human specimens and frequently isolated with Staphylococcus aureus. Modulation of staphylococci virulence by H. kunzii has been shown in an infection model of Caenorhabditis elegans. The aim of this study was to compare the genomes of two H. kunzii strains isolated from foot ulcers -isolate H13 and H10 showing high or low impact on S. aureus virulence, respectively- and the H. kunzii ATCC51366 strain. Whole genome analyses revealed some differences between the two strains: length (2.06 Mb (H13) and 2.05 Mb (H10) bp), GC content (29.3% (H13) and 29.5% (H10)) and gene content (1,884 (H13) and 1,786 (H10) predicted genes). The core-proteome phylogenies within the genus characterised H. kunzii H13 and H10 as genetically similar to their ancestor. The main differences between the strains were mainly in sugar-associated transporters and various hypothetical proteins. Five targets were identified as potentially involved in S. aureus virulence modulation in both genomes: the two-component iron export system and three autoinducer-like proteins. Moreover, H13 strain harbours a prophage inserted in 1,261,110-1,295,549 (attL-attR), which is absent in H10 strain. The prophage PhiCD38_2 was previously reported for its ability to modulate secretion profile, reinforcing the autoinducer-like hypothesis. In the future, transcriptomics or metaproteomics approaches could be performed to better characterize the H13 strain and possibly identify the underlying mechanism for S. aureus virulence modulation.

Healthcare students' prevention training in a sanitary service: analysis of health education interventions in schools of the Grenoble academy.

BACKGROUND: The sanitary service is a mandatory prevention training programme for all French healthcare students. Students receive training and then have to design and carry out a prevention intervention with various populations. The aim of this study was to analyse the type of health education interventions carried out in schools by healthcare students from one university in order to describe the topics covered and the methods used. METHOD: The 2021-2022 sanitary service of University Grenoble Alpes involved students in maieutic, medicine, nursing, pharmacy and physiotherapy. The study focused on students who intervened in school contexts. The intervention reports written by the students were read doubly by independent evaluators. Information of interest was collected in a standardised form. RESULTS: Out of the 752 students involved in the prevention training program, 616 (82%) were assigned to 86 schools, mostly primary schools (58%), and wrote 123 reports on their interventions. Each school hosted a median of 6 students from 3 different fields of study. The interventions involved 6853 pupils aged between 3 and 18 years. The students delivered a median of 5 health prevention sessions to each pupil group and spent a median of 25 h (IQR: 19-32) working on the intervention. The themes most frequently addressed were screen use (48%), nutrition (36%), sleep (25%), harassment (20%) and personal hygiene (15%). All students used interactive teaching methods such as workshops, group games or debates that was addressed to pupils' psychosocial (mainly cognitive and social) competences. The themes and tools used differed according to the pupils' grade levels. CONCLUSION: This study showed the feasibility of conducting health education and prevention activities in schools by healthcare students from five professional fields who had received appropriate training. The students were involved and creative, and they were focused on developing pupils' psychosocial competences.

Effects of a healthcare students' prevention intervention for school children on their own substance use: a before-after study.

BACKGROUND: Cognitive dissonance theory and research has suggested that engaging in prevention interventions for other students may be a means of reducing one's own problematic behaviors in order to reduce potential cognitive dissonance. This study assessed the effects of a new mandatory prevention intervention program for healthcare students in France. The aim was to measure the effects of engaging in a prevention program in schools on the usual increase in substance use in student populations. METHODS: Healthcare students were trained in a French university to develop psychosocial competences as a health promotion means (FEPS training) or more specifically to prevent substance use in teenagers (Unplugged program training). The students (n = 314) who accepted to take part in the study from both groups completed questionnaires before their interventions in schools, and at the end of the year, measuring their representations and behaviors regarding psychoactive substances. RESULTS: The results indicated a significant reduction in alcohol consumption in terms of quantity, but no significant reduction in tobacco and marijuana consumption. CONCLUSIONS: This study showed that, contrary to the usual increase in substance use in students as they advance in their year, the students who took part in this study showed reduced self-reported consumption of alcohol after they had performed the prevention intervention in schools regardless of the type of training they had received (general health promotion vs. specific substance use prevention program). Limitations and future perspectives are discussed.

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.

Influenza A viruses limit NLRP3-NEK7-complex formation and pyroptosis in human macrophages.

Pyroptosis is a fulminant form of macrophage cell death, contributing to release of pro-inflammatory cytokines. In humans, it depends on caspase 1/4-activation of gasdermin D and is characterized by the release of cytoplasmic content. Pathogens apply strategies to avoid or antagonize this host response. We demonstrate here that a small accessory protein (PB1-F2) of contemporary H5N1 and H3N2 influenza A viruses (IAV) curtails fulminant cell death of infected human macrophages. Infection of macrophages with a PB1-F2-deficient mutant of a contemporary IAV resulted in higher levels of caspase-1 activation, cleavage of gasdermin D, and release of LDH and IL-1ß. Mechanistically, PB1-F2 limits transition of NLRP3 from its auto-repressed and closed confirmation into its active state. Consequently, interaction of a recently identified licensing kinase NEK7 with NLRP3 is diminished, which is required to initiate inflammasome assembly.

An interventional quasi-experimental study to evaluate the impact of a rapid screening strategy in improving control of nosocomial extended-spectrum beta-lactamase-producing Enterobacterales and carbapenemase-producing organisms in critically ill patients.

INTRODUCTION: Rapid molecular tests could accelerate the control of extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) and carbapenemase-producing organisms (CPO) in intensive care units (ICUs). OBJECTIVE AND METHODS: This interventional 12-month cohort study compared a loop-mediated isothermal amplification (LAMP) assay performed directly on rectal swabs with culturing methods (control period, 6 months), during routine ICU screening. Contact precautions (CP) were implemented for CPO or non-E. coli ESBL-producing Enterobacterales (nEcESBL-PE) carriers. Using survival analysis, we compared the time intervals from admission to discontinuation of unnecessary preemptive CP among patients at-risk and the time intervals from screening to implementation of CP among newly identified carriers. We also compared diagnostic performances, and nEcESBL-PE/CPO acquisition rates. This study is registered, ISRCTN 23588440. RESULTS: We included 1043 patients. During the intervention and control phases, 92/147 (62.6%) and 47/86 (54.7%) of patients at-risk screened at admission were candidates for early discontinuation of preemptive CP. The LAMP assay had a positive predictive value (PPV) of 44.0% and a negative predictive value (NPV) of 99.9% for CPO, and 55.6% PPV and 98.2% NPV for nEcESBL-PE. Due to result notification and interpretation challenges, the median time from admission to discontinuation of preemptive CP increased during the interventional period from 80.5 (95% CI 71.5-132.1) to 88.3 (95% CI 57.7-103.7) hours (p = 0.47). Due to the poor PPV, we had to stop using the LAMP assay to implement CP. No difference was observed regarding the incidence of nEcESBL-PE and CPO acquisition. CONCLUSION: A rapid screening strategy with LAMP assays performed directly on rectal swabs had no benefit for infection control in a low-endemicity setting.

Student characteristics associated with interpersonal skills in medical consultations.

BACKGROUND: The quality of medical care depends on effective physician-patient communication. Interpersonal skills can be improved through teaching, but the determinants are poorly understood. We therefore assessed the factors associated with the interpersonal skills of medical students during simulated medical consultations. METHODS: We conducted a cross-sectional study of fourth-year medical students participating in simulated consultations with standardized patients. Each video-recorded medical consultation was independently assessed by two raters, using a cross-cultural adaptation of the Four Habits Coding Scheme (4-HCS) into French. We then collected information on demographics and education-related characteristics. The relationship between the overall 4-HCS score and student characteristics was modeled using univariable and multivariable linear regression. RESULTS: Our analytical sample included 165 medical students for analysis. The factors significantly associated with 4-HCS score were gender (ß = - 4.8, p = 0.011) and completion of an international clinical placement (ß = 6.2, p = 0.002) or a research laboratory clerkship (ß = 6.5, p = 0.005). Education-related characteristics, multiple-choice examinations in the first to third preclinical years, and number of medicine or surgery clerkships were not significantly associated with 4-HCS score. CONCLUSIONS: Undergraduate students with higher level of interpersonal skills during video-recorded medical consultations with standardized patients are more likely to be female, to have completed international clinical placement as part of the ERASMUS exchange program or research laboratory clerkship.

Direct phone communication to primary care physician to plan discharge from hospital: feasibility and benefits.

BACKGROUND: The discharge summary is the main vector of communication at the time of hospital discharge, but it is known to be insufficient. Direct phone contact between hospitalist and primary care physician (PCP) at discharge could ensure rapid transmission of information, improve patient safety and promote interprofessional collaboration. The objective of this study was to evaluate the feasibility and benefit of a phone call from hospitalist to PCP to plan discharge. METHODS: This study was a prospective, single-center, cross-sectional observational study. It took place in an acute medicine unit of a French university hospital. The hospitalist had to contact the PCP by telephone within 72 h prior discharge, making a maximum of 3 call attempts. The primary endpoint was the proportion of patients whose primary care physician could be reached by telephone at the time of discharge. The other criteria were the physicians' opinions on the benefits of this contact and its effect on readmission rates. RESULTS: 275 patients were eligible. 8 hospitalists and 130 PCPs gave their opinion. Calls attempts were made for 71% of eligible patients. Call attempts resulted in successful contact with the PCP 157 times, representing 80% of call attempts and 57% of eligible patients. The average call completion rate was 47%. The telephone contact was perceived by hospitalist as useful and providing security. The PCPs were satisfied and wanted this intervention to become systematic. Telephone contact did not reduce the readmission rate. CONCLUSIONS: Despite the implementation of a standardized process, the feasibility of the intervention was modest. The main obstacle was hospitalists lacking time and facing difficulties in reaching the PCPs. However, physicians showed desire to communicate directly by telephone at the time of discharge. TRIAL REGISTRATION: French C.N.I.L. registration number 2108852. Registration date October 12, 2017.

YpdA, a putative bacillithiol disulfide reductase, contributes to cellular redox homeostasis and virulence in Staphylococcus aureus.

The intracellular redox environment of Staphylococcus aureus is mainly buffered by bacillithiol (BSH), a low molecular weight thiol. The identity of enzymes responsible for the recycling of oxidized bacillithiol disulfide (BSSB) to the reduced form (BSH) remains elusive. We examined YpdA, a putative bacillithiol reductase, for its role in maintaining intracellular redox homeostasis. The ypdA mutant showed increased levels of BSSB and a lower bacillithiol redox ratio vs. the isogenic parent, indicating a higher level of oxidative stress within the bacterial cytosol. We showed that YpdA consumed NAD(P)H; and YpdA protein levels were augmented in response to stress. Wild type strains overexpressing YpdA showed increased tolerance to oxidants and electrophilic agents. Importantly, YpdA overexpression in the parental strain caused an increase in BSH levels accompanied by a decrease in BSSB concentration in the presence of stress, resulting in an increase in bacillithiol redox ratio vs. the vector control. Additionally, the ypdA mutant exhibited decreased survival in human neutrophils (PMNs) as compared with the parent, while YpdA overexpression protected the resulting strain from oxidative stress in vitro and from killing by human neutrophils ex vivo. Taken together, these data present a new role for YpdA in S. aureus physiology and virulence through the bacillithiol system.

Bilan du service sanitaire 2018-2019 de l'Université Grenoble Alpes, inter-filière médecine, pharmacie, maïeutique, kinésithérapie.

OBJECTIVE: "Health service", a French national service-learning program for health profession students, was launched in 2018. It aimed at developing knowledge and skills in health promotion and prevention. The purpose of this study was to assess the local implementation of this program, among medical, pharmacy, midwifery and physical therapy students at the Grenoble Alps University. METHODS: Relevant data were extracted from the placement reports, the directors' feedback forms and an on-line questionnaire for students. We described the teams, the actions, the targeted publics, the students' satisfaction and directors' satisfaction. RESULTS: 400 students participated in this service-learning program (207 medical students, 93 pharmacy students, 39 midwifery students and 61 physical therapy students). 92 teams took actions in 91 institutions, including 90 secondary schools. 96.0% of the students were in interprofessional teams. Of 7,926 people reached, 7,872 (99.3%) were secondary school pupils. The main issues addressed were the substance-use prevention program based on life skills development, Unplugged (55 schools) and screen time and cyberstalking (17 schools). CONCLUSIONS: This program achieved interprofessional education and practice, with health-student-delivered activities. Interdisciplinarity was a core strength of the "Health service". Areas for improvement were the communication and the reimbursement of transportation expenses.

[Evaluation of an interprofessional service-learning program among health profession students: the experience of Grenoble Alps University] / Bilan du service sanitaire 2018-2019 de l'Université Grenoble Alpes, inter-filière médecine, pharmacie, maïeutique, kinésithérapie.

OBJECTIVE: “Health service”, a French national service-learning program for health profession students, was launched in 2018. It aimed at developing knowledge and skills in health promotion and prevention. The purpose of this study was to assess the local implementation of this program, among medical, pharmacy, midwifery and physical therapy students at the Grenoble Alps University. METHODS: Relevant data were extracted from the placement reports, the directors’ feedback forms and an on-line questionnaire for students. We described the teams, the actions, the targeted publics, the students’ satisfaction and directors’ satisfaction. RESULTS: 400 students participated in this service-learning program (207 medical students, 93 pharmacy students, 39 midwifery students and 61 physical therapy students). 92 teams took actions in 91 institutions, including 90 secondary schools. 96.0% of the students were in interprofessional teams. Of 7,926 people reached, 7,872 (99.3%) were secondary school pupils. The main issues addressed were the substance-use prevention program based on life skills development, Unplugged (55 schools) and screen time and cyberstalking (17 schools). CONCLUSIONS: This program achieved interprofessional education and practice, with health-student-delivered activities. Interdisciplinarity was a core strength of the “Health service”. Areas for improvement were the communication and the reimbursement of transportation expenses.

[Evaluation of an interprofessional service-learning program among health profession students: the experience of Grenoble Alps University]. / Bilan du service sanitaire 2018-2019 de l'Université Grenoble Alpes, inter-filière médecine, pharmacie, maïeutique, kinésithérapie.

OBJECTIVE: “Health service”, a French national service-learning program for health profession students, was launched in 2018. It aimed at developing knowledge and skills in health promotion and prevention. The purpose of this study was to assess the local implementation of this program, among medical, pharmacy, midwifery and physical therapy students at the Grenoble Alps University. METHODS: Relevant data were extracted from the placement reports, the directors’ feedback forms and an on-line questionnaire for students. We described the teams, the actions, the targeted publics, the students’ satisfaction and directors’ satisfaction. RESULTS: 400 students participated in this service-learning program (207 medical students, 93 pharmacy students, 39 midwifery students and 61 physical therapy students). 92 teams took actions in 91 institutions, including 90 secondary schools. 96.0% of the students were in interprofessional teams. Of 7,926 people reached, 7,872 (99.3%) were secondary school pupils. The main issues addressed were the substance-use prevention program based on life skills development, Unplugged (55 schools) and screen time and cyberstalking (17 schools). CONCLUSIONS: This program achieved interprofessional education and practice, with health-student-delivered activities. Interdisciplinarity was a core strength of the “Health service”. Areas for improvement were the communication and the reimbursement of transportation expenses.

Antibiotics Stimulate Formation of Vesicles in Staphylococcus aureus in both Phage-Dependent and -Independent Fashions and via Different Routes.

Bacterial membrane vesicle research has so far focused mainly on Gram-negative bacteria. Only recently have Gram-positive bacteria been demonstrated to produce and release extracellular membrane vesicles (MVs) that contribute to bacterial virulence. Although treatment of bacteria with antibiotics is a well-established trigger of bacterial MV formation, the underlying mechanisms are poorly understood. In this study, we show that antibiotics can induce MVs through different routes in the important human pathogen Staphylococcus aureus DNA-damaging agents and antibiotics inducing the SOS response triggered vesicle formation in lysogenic strains of S. aureus but not in their phage-devoid counterparts. The ß-lactam antibiotics flucloxacillin and ceftaroline increased vesicle formation in a prophage-independent manner by weakening the peptidoglycan layer. We present evidence that the amount of DNA associated with MVs formed by phage lysis is greater than that for MVs formed by ß-lactam antibiotic-induced blebbing. The purified MVs derived from S. aureus protected the bacteria from challenge with daptomycin, a membrane-targeting antibiotic, both in vitro and ex vivo in whole blood. In addition, the MVs protected S. aureus from killing in whole blood, indicating that antibiotic-induced MVs function as a decoy and thereby contribute to the survival of the bacterium.

The TIR Homologue Lies near Resistance Genes in Staphylococcus aureus, Coupling Modulation of Virulence and Antimicrobial Susceptibility.

Toll/interleukin-1 receptor (TIR) domains in Toll-like receptors are essential for initiating and propagating the eukaryotic innate immune signaling cascade. Here, we investigate TirS, a Staphylococcus aureus TIR mimic that is part of a novel bacterial invasion mechanism. Its ectopic expression in eukaryotic cells inhibited TLR signaling, downregulating the NF-kB pathway through inhibition of TLR2, TLR4, TLR5, and TLR9. Skin lesions induced by the S. aureus knockout tirS mutant increased in a mouse model compared with wild-type and restored strains even though the tirS-mutant and wild-type strains did not differ in bacterial load. TirS also was associated with lower neutrophil and macrophage activity, confirming a central role in virulence attenuation through local inflammatory responses. TirS invariably localizes within the staphylococcal chromosomal cassettes (SCC) containing the fusC gene for fusidic acid resistance but not always carrying the mecA gene. Of note, sub-inhibitory concentration of fusidic acid increased tirS expression. Epidemiological studies identified no link between this effector and clinical presentation but showed a selective advantage with a SCCmec element with SCC fusC/tirS. Thus, two key traits determining the success and spread of bacterial infections are linked.