Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Behav Sci Law ; 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38801740

RESUMO

The present study examined distinctions between child (n = 30) and adult (n = 212) sexual homicide offenders (SHOs) in Australia and New Zealand, contributing to the limited international research on the subject. Data, primarily sourced from judges' sentencing comments on AustLII and New Zealand Legal Information Institute, revealed significant differences. Child SHOs displayed elevated rates of pedophilia, sexual deviance, and adverse childhood experiences, including sexual abuse. They were more likely to be married, cohabitate, and target familial victims. Their crimes were more often committed during daylight and outdoors, involving tactics such as victim conning, restraints, strangulation, and hiding victim's bodies. No significant group differences emerged regarding offenders' psychopathy or sexual sadism scores. Results were interpreted in line with child SHOs' deviant sexual preferences and the routine activity theory. The study, as the first investigating child sexual homicides in Australia and New Zealand, sets the foundation for an evidence-based approach to policy and practice.

2.
Pediatr Dent ; 45(6): 497-507, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38129749

RESUMO

Purpose: To evaluate the relationship between demographics, dental beliefs and practices, fatalism, oral health self-efficacy, and oral health fatalism (OHF) among parent (guardian, caregivers). Methods: English-speaking parents of children presenting for dental care at a hospital dental clinic, a dental surgery center, and two private practices answered a 33-item questionnaire regarding demographics, general fatalistic views, and dental beliefs, practices, and history. Participants rated their agreement with the OHF statement: "Most children eventually develop dental cavities." Results: More than half (58.4 percent) of parent respondents (n equals 332) were Caucasian, and 44.6 percent had education beyond high school. Most were female (81.3 percent), with public (Medicaid) insurance (67.5 percent), and were raising three (average) children. Less than 30 percent endorsed the OHF statement, and 42.5 percent were neutral. Higher OHF was found in parents of children with Medicaid insurance (P=0.02), fair (P=0.01) or poor (P=0.03) dental health, previous caries history (P=0.02), and those attending their first dental visit (P=0.03). Higher OHF was found in parents whose children do not brush their teeth when asked (P=0.02) or who do not behave when a parent helps (P=0.02), as well as those who subscribe to general fatalism beliefs (P=0.002). Conclusions: Higher oral health fatalism was associated with general fatalism, low oral health self-efficacy, parents of children with Medicaid insurance, suboptimal dental health, and first dental visits. Future studies investigating whether OHF can change over time and the role providers play in OHF can help dental professionals understand parent health behaviors and plan for health promotion interventions.


Assuntos
Cárie Dentária , Saúde Bucal , Criança , Humanos , Feminino , Masculino , Autoeficácia , Promoção da Saúde , Pais/educação , Demografia
3.
Infect Immun ; 91(12): e0024723, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37991349

RESUMO

There are currently no approved vaccines against the opportunistic pathogen Pseudomonas aeruginosa. Among vaccine targets, the lipopolysaccharide (LPS) O antigen of P. aeruginosa is the most immunodominant protective candidate. There are 20 different O antigens composed of different repeat sugar structures conferring serogroup specificity, and 10 are found most frequently in infection. Thus, one approach to combat infection by P. aeruginosa could be to generate immunity with a vaccine cocktail that includes all these serogroups. Serogroup O9 is 1 of the 10 serogroups commonly found in infection, but it has never been developed into a vaccine, due in part to the acid-labile nature of the O9 polysaccharide. Our laboratory has previously shown that intranasal administration of an attenuated Salmonella strain expressing the P. aeruginosa serogroup O11 LPS O antigen was effective in clearing bacteria and preventing mortality in mice following intranasal challenge with serogroup O11 P. aeruginosa. Consequently, we set out to develop a P. aeruginosa serogroup O9 vaccine using a similar approach. Here, we show that Salmonella expressing serogroup O9 triggered an antibody-mediated immune response following intranasal administration to mice and that it conferred protection from P. aeruginosa serogroup O9 in a murine model of acute pneumonia.


Assuntos
Antígenos O , Infecções por Pseudomonas , Camundongos , Animais , Lipopolissacarídeos , Pseudomonas aeruginosa , Sorogrupo , Vacinas Bacterianas , Anticorpos Antibacterianos
4.
bioRxiv ; 2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37502855

RESUMO

There are currently no approved vaccines against the opportunistic pathogen Pseudomonas aeruginosa. Among vaccine targets, the lipopolysaccharide (LPS) O antigen of P. aeruginosa is the most immunodominant protective candidate. There are twenty different O antigens composed of different repeat sugars structures conferring serogroup specificity, and ten are found most frequently in infection. Thus, one approach to combat infection by P. aeruginosa could be to generate immunity with a vaccine cocktail that includes all these serogroups. Serogroup O9 is one of the ten serogroups commonly found in infection, but it has never been developed into a vaccine, likely due, in part, to the acid labile nature of the O9 polysaccharide. Our laboratory has previously shown that intranasal administration of an attenuated Salmonella strain expressing the P. aeruginosa serogroup O11 LPS O antigen was effective in clearing and preventing mortality in mice following intranasal challenge with serogroup O11 P. aeruginosa. Consequently, we set out to develop a P. aeruginosa serogroup O9 vaccine using a similar approach. Here we show that Salmonella expressing serogroup O9 triggered an antibody-mediated immune response following intranasal administration to mice and that it conferred protection from P. aeruginosa serogroup O9 in a murine model of acute pneumonia.

5.
Front Psychol ; 14: 1070484, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36998362

RESUMO

The grievance fueled violence paradigm encompasses various forms of targeted violence but has not yet been extended to the theoretical discussion of sexual violence. In this article, we argue that a wide range of sexual offenses can be usefully conceptualized as forms of grievance fueled violence. Indeed, our assertion that sexual violence is often grievance fueled is unoriginal. More than 40 years of sexual offending research has discussed the pseudosexual nature of much sexual offending, and themes of anger, power, and control - themes that draw clear parallels to the grievance fueled violence paradigm. Therefore, we consider the opportunities for theoretical and practical advancement through the merging of ideas and concepts from the two fields. We examine the scope of grievance in the context of understanding sexual violence, and we look to the role of grievance in the trajectory toward both sexual and nonsexual violence, as well as factors that might distinguish grievance fueled sexual from nonsexual violence. Finally, we discuss future research directions and make recommendations for clinical practice. Specifically, we suggest that grievance represents a promising treatment target where risk is identified for both sexual and nonsexual violence.

6.
Wound Repair Regen ; 30(2): 151-155, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35076141

RESUMO

Due to the need for more information about Department of Defense sponsored wound healing research, the Wound Healing Foundation initiated the writing of this article. It briefly describes the Vision, Mission and Goals of the Department of Defense Strategic Medical Research Plan. It also describes the current objectives of Department of Defense research funding and where to access this information in detail. The grant cycle, the timing of request for proposals and some of the specifics of their requirements are also mentioned. A brief discussion of budgeting and overhead is also included.


Assuntos
Pesquisa Biomédica , Cicatrização , Projetos de Pesquisa , Redação
7.
Psychiatr Psychol Law ; 28(1): 120-134, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34552383

RESUMO

There is limited information regarding the use of risk assessment tools with aging offender populations. It is known that the likelihood of offending behaviour decreases with age, a small group of men either continue or begin to offend sexually in the later decades of life. The current study investigated the predictive validity of the Static-99 and the Static-99R, in a sample of convicted Australian sex offenders aged 50 and older. A sample of 118 participants was identified, of which 17 (14.4%) re-offended within a follow-up period ranging from four months to 20 years (M = 9.07 years). There were seven recidivists (13.46%) above the age of 60 years (n = 52) and 10 aged 40 to 59.9 years (n = 66). Both the Static-99 and Static-99R demonstrated moderate predictive validity with both age groups. The limitations of this study are discussed as well as recommendations for future research.

8.
J Plast Reconstr Aesthet Surg ; 74(2): 316-326, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33036926

RESUMO

INTRODUCTION: A solid organ transplant (SOT) recipient, already taking immunosuppression, may represent the ideal candidate for vascularised composite allograft transplantation (VCA). However, concerns have been raised about the potential risk of SOT loss or the need for increased immunosuppression to sustain the VCA. This systematic review examines all published cases of SOT recipients who have received a VCA to establish associated morbidity and immunosuppression requirements. METHODS: A systematic review was performed in accordance with the PRISMA guidelines. The PubMed, MEDLINE and EMBASE databases were searched for original articles published between January 1997 and May 2019. Only articles relating to patients who had received both a VCA and SOT with a reported follow up of greater than six months were included. RESULTS: Fifteen articles were identified, including data from 39 VCAs in 37 patients. There was no increase in the number of SOT rejection episodes, complications such as post-transplant lymphoproliferative disorder or graft versus host disease, de novo donor specific HLA antibodies or short-term risks to the recipient when compared with SOT in isolation. One child required a sustained increase in their baseline immunosuppression following bilateral hand transplantation. CONCLUSIONS: In this small heterogeneous cohort, the addition of a VCA to a SOT does not appear to increase the short-term risks to the SOT or the patient with comparable results to SOT in isolation. However, data are often poorly reported and longer-term follow up and uniform reporting of outcomes would be beneficial to more accurately assess the safety profile of combining VCA with SOT.


Assuntos
Rejeição de Enxerto/prevenção & controle , Imunossupressores/uso terapêutico , Alotransplante de Tecidos Compostos Vascularizados/métodos , Humanos , Complicações Pós-Operatórias/epidemiologia , Resultado do Tratamento
9.
J Clin Pediatr Dent ; 44(6): 400-406, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33378463

RESUMO

OBJECTIVES: The objective was to compare dental visits, procedures, and expenditures in children with newly diagnosed caries. STUDY DESIGN: A retrospective chart review was conducted in a two dentist private practice in North Carolina. Demographic data, health status, and dental treatment data was collected. Analysis relied upon nearest neighbor matching to estimate the average treatment effects of silver diamine fluoride (SDF) by comparing children who received SDF to children who did not receive SDF (n=104 matches). RESULTS: After matching on age, gender, race, insurance status, dental cooperation, and dmft, the SDF group had significantly more dental visits (average treatment effect on treated (ATET)=1.08), fewer restorations (ATET=2.37), and fewer restorative and overall treatment expenditures (ATET=$402 and $292, respectively) than the non-SDF group. The SDF group more frequently received treatment under general anesthesia (26% vs 7%), so this group was excluded in secondary analysis. Among children who did not receive general anesthesia, the SDF group had significantly more dental visits (ATET=.66), fewer restorations (ATET=2.74), and fewer restorative and overall treatment expenditures (ATET=$566 and $515, respectively) than the non-SDF group. CONCLUSION: SDF can offer cost savings when used as an adjunct to, rather than a complete replacement for, restorative treatment in young children.


Assuntos
Cariostáticos , Cárie Dentária , Cariostáticos/uso terapêutico , Criança , Pré-Escolar , Fluoretos Tópicos , Humanos , Compostos de Amônio Quaternário , Estudos Retrospectivos , Compostos de Prata
10.
JAMA Netw Open ; 3(7): e209393, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32663307

RESUMO

Importance: Trauma is the leading cause of death for US individuals younger than 45 years, and uncontrolled hemorrhage is a major cause of trauma mortality. The US military's medical advancements in the field of prehospital hemorrhage control have reduced battlefield mortality by 44%. However, despite support from many national health care organizations, no integrated approach to research has been made regarding implementation, epidemiology, education, and logistics of prehospital hemorrhage control by layperson immediate responders in the civilian sector. Objective: To create a national research agenda to help guide future work for prehospital hemorrhage control by laypersons. Evidence Review: The 2-day, in-person, National Stop the Bleed (STB) Research Consensus Conference was conducted on February 27 to 28, 2019, to identify and achieve consensus on research gaps. Participants included (1) subject matter experts, (2) professional society-designated leaders, (3) representatives from the federal government, and (4) representatives from private foundations. Before the conference, participants were provided a scoping review on layperson prehospital hemorrhage control. A 3-round modified Delphi consensus process was conducted to determine high-priority research questions. The top items, with median rating of 8 or more on a Likert scale of 1 to 9 points, were identified and became part of the national STB research agenda. Findings: Forty-five participants attended the conference. In round 1, participants submitted 487 research questions. After deduplication and sorting, 162 questions remained across 5 a priori-defined themes. Two subsequent rounds of rating generated consensus on 113 high-priority, 27 uncertain-priority, and 22 low-priority questions. The final prioritized research agenda included the top 24 questions, including 8 for epidemiology and effectiveness, 4 for materials, 9 for education, 2 for global health, and 1 for health policy. Conclusions and Relevance: The National STB Research Consensus Conference identified and prioritized a national research agenda to support laypersons in reducing preventable deaths due to life-threatening hemorrhage. Investigators and funding agencies can use this agenda to guide their future work and funding priorities.


Assuntos
Serviços Médicos de Emergência , Hemorragia , Projetos de Pesquisa , Ferimentos e Lesões , Pesquisa Biomédica/métodos , Consenso , Técnica Delphi , Serviços Médicos de Emergência/métodos , Serviços Médicos de Emergência/organização & administração , Hemorragia/etiologia , Hemorragia/mortalidade , Hemorragia/terapia , Humanos , Inquéritos e Questionários , Ferimentos e Lesões/complicações , Ferimentos e Lesões/mortalidade
12.
J Trauma Acute Care Surg ; 87(1S Suppl 1): S119-S127, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31246915

RESUMO

BACKGROUND: Coagulation monitoring capabilities during transport are limited. Thromboelastography (TEG) is a whole-blood clotting test measuring clot formation, stabilization, and fibrinolysis and is traditionally performed in a laboratory. We evaluated a new point-of-care TEG analyzer, TEG 6s (Haemonetics, Braintree, MA), in a large animal model of combat-relevant trauma managed with extracorporeal life support during ground and high-altitude aeromedical evacuation. The objective was to compare TEG 6s used during transport versus the predicate device, TEG 5000, used in the laboratory. We hypothesized that TEG 6s would be comparable with TEG 5000 during dynamically changing transport conditions. METHODS: Thromboelastography parameters (R, K, angle, MA, LY30) derived by TEG 6s and TEG 5000 were compared during transport of 8 swine. TEG 6s was transported with animals during ground transport and flight. TEG 5000 was stationary in an adjacent building. TEG 6s activated clotting time (ACT) was compared with a Hemochron Junior ACT analyzer (Accriva Diagnostics, San Diego, CA). Statistics were performed using SAS 9.4 with Deming regressions, Spearman correlations, and average differences compared. RESULTS: Correlation between devices was stronger at sea-level (R, r = 0.7413; K, r = 0.7115; angle, r = 0.7192; MA, r = 0.8386; LY30, r = 0.9099) than during high-altitude transport (R, r = 0.4787; K, r = 0.4007; angle, r = 0.3706; MA, r = 0.6573; LY30, r = 0.8481). Method agreement was comparable during stationary operation (R, r = 0.7978; K, r = 0.7974; angle, r = 0.7574; MA, r = 0.7841; LY30, r = 0.9140) versus ground transport (R, r = 0.7927; K, r = 0.6246; angle, r = 0.6967; MA, r = 0.9163; LY30, r = 0.8603). TEG 6s ACT trended higher than Hemochron ACT when subjects were heparinized (average difference, 1,442 ± 1,703 seconds) without a methodological difference by Deming regression. CONCLUSION: Mobile TEG 6s during ground and altitude transport is feasible and provides unprecedented information to guide coagulation management. Future studies should assess the precision and accuracy of TEG 6s during transport of critically ill.


Assuntos
Oxigenação por Membrana Extracorpórea , Sistemas Automatizados de Assistência Junto ao Leito , Tromboelastografia/instrumentação , Resgate Aéreo , Altitude , Animais , Suínos
13.
Transfusion ; 59(S2): 1587-1592, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30980738

RESUMO

Recent studies have demonstrated that early transfusion of plasma or RBCs improves survival in patients with severe trauma and hemorrhagic shock. Time to initiate transfusion is the critical factor. It is essential that transfusion begin in the prehospital environment when transport times are longer than approximately 15 to 20 minutes. Unfortunately, logistic constraints severely limit the use of blood products in the prehospital setting, especially in military, remote civilian, and mass disaster circumstances, where the need can be most acute. US military requirements for logistically supportable blood products are projected to increase dramatically in future conflicts. Although dried plasma products have been available and safely used in a number of countries for over 20 years, there is no dried plasma product commercially available in the United States. A US Food and Drug Administration-approved dried plasma is urgently needed. Considering the US military, disaster preparedness, and remote civilian trauma perspectives, this is an urgent national health care issue.


Assuntos
Transfusão de Componentes Sanguíneos/métodos , Medicina de Desastres/métodos , Medicina Militar/métodos , Plasma , Choque Hemorrágico/terapia , Aprovação de Drogas , Humanos , Estados Unidos , United States Food and Drug Administration
14.
PLoS One ; 14(1): e0210914, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30677062

RESUMO

BACKGROUND: Currently, patients receiving vascularized composite allotransplantation (VCA) grafts must take long-term systemic immunosuppressive therapy to prevent immunologic rejection. The morbidity and mortality associated with these medications is the single greatest barrier to more patients being able to receive these life-enhancing transplants. In contrast to solid organs, VCA, exemplified by hand or face transplants, allow visual diagnosis of clinical acute rejection (AR), directed biopsy and targeted graft therapies. Local immunosuppression in VCA could reduce systemic drug exposure and limit adverse effects. This proof of concept study evaluated, in a large animal forelimb VCA model, the efficacy and tolerability of a novel graft-implanted enzyme-responsive, tacrolimus (TAC)-eluting hydrogel platform, in achieving long-term graft survival. METHODS: Orthotopic forelimb VCA were performed in single haplotype mismatched mini-swine. Controls (n = 2) received no treatment. Two groups received TAC hydrogel: high dose (n = 4, 91 mg TAC) and low dose (n = 4, 49 mg TAC). The goal was to find a dose that was tolerable and resulted in long-term graft survival. Limbs were evaluated for clinical and histopathological signs of AR. TAC levels were measured in serial blood and skin tissue samples. Tolerability of the dose was evaluated by monitoring animal feeding behavior and weight. RESULTS: Control limbs underwent Banff Grade IV AR by post-operative day six. Low dose TAC hydrogel treatment resulted in long-term graft survival time to onset of Grade IV AR ranging from 56 days to 93 days. High dose TAC hydrogel also resulted in long-term graft survival (24 to 42 days), but was not well tolerated. CONCLUSION: Graft-implanted TAC-loaded hydrogel delays the onset of Grade IV AR of mismatched porcine forelimb VCA grafts, resulting in long term graft survival and demonstrates dose-dependent tolerability.


Assuntos
Aloenxertos Compostos , Tacrolimo/administração & dosagem , Alotransplante de Tecidos Compostos Vascularizados/métodos , Animais , Aloenxertos Compostos/efeitos dos fármacos , Aloenxertos Compostos/imunologia , Aloenxertos Compostos/patologia , Implantes de Medicamento , Membro Anterior/transplante , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/efeitos dos fármacos , Sobrevivência de Enxerto/imunologia , Hidrogéis , Imunossupressores/administração & dosagem , Imunossupressores/farmacocinética , Modelos Animais , Estudo de Prova de Conceito , Suínos , Porco Miniatura , Tacrolimo/farmacocinética
15.
Ann Plast Surg ; 82(4): 452-458, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30628928

RESUMO

INTRODUCTION: Vascularized composite allotransplantation can reconstruct devastating tissue loss by replacing like-with-like tissues, most commonly in the form of hand or face transplantation. Unresolved technical and ethical challenges have meant that such transplants remain experimental treatments. The most significant barrier to expansion of this field is the requirement for systemic immunosuppression, its toxicity and effect on longevity.Hydrogen sulfide (H2S) has been shown experimentally to ameliorate the ischemia reperfusion injury associated with composite tissue autotransplantation, which has been linked to acute rejection in solid organ transplantation. In this protocol, a large-animal model was used to evaluate the effect of H2S on acute rejection after composite tissue allotransplantation. MATERIALS AND METHODS: A musculocutaneous flap model in SLA-mismatched swine was used to evaluate acute rejection of allotransplants in 2 groups: control animals (n = 8) and a treatment group in which the allografts were pretreated with hydrogen sulfide (n = 8). Neither group was treated with systemic immunosuppression. Acute rejection was graded clinically and histopathologically by an independent, blinded pathologist. Data were analyzed by t tests with correction for multiple comparisons by the Holm-Sídák method. RESULTS: Clinically, H2S-treated tissue composites showed a delay in the onset of rejection that was statistically significant from postoperative day 6. Histopathologically, this difference between groups was also apparent, although evidence of a difference in groups disappeared beyond day 10. CONCLUSIONS: Targeted hydrogen sulfide treatment of vascularized composite allografts immediately before transplantation can delay acute rejection. This may, in turn, reduce or obviate the requirement for systemic immunosuppression.


Assuntos
Aloenxertos Compostos/transplante , Rejeição de Enxerto/prevenção & controle , Sulfeto de Hidrogênio/farmacologia , Retalho Miocutâneo/transplante , Alotransplante de Tecidos Compostos Vascularizados/métodos , Doença Aguda , Animais , Modelos Animais de Doenças , Sobrevivência de Enxerto , Análise Multivariada , Cuidados Pré-Operatórios/métodos , Distribuição Aleatória , Medição de Risco , Suínos , Resultado do Tratamento , Alotransplante de Tecidos Compostos Vascularizados/efeitos adversos , Cicatrização/fisiologia
17.
J Trauma Acute Care Surg ; 85(1S Suppl 2): S1-S3, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29953030

RESUMO

This issue of the Journal of Trauma and Acute Care Surgery features topics from the 2017 Military Health System Research Symposium and starts a second decade of partnership between the Combat Casualty Care Research Program (CCCRP) and the journal. This publication comes at a time of significant change for the CCCRP, as it responds to military planning for the future multidomain battlefield (MDB). The projected MDB portends markedly different operational scenarios than those conducted over the past 17 years. Emerging threats around the globe have the Department of Defense preparing for more complex battlefields that are larger in size and scope and which pit the United States against better equipped and more sophisticated adversaries. As the CCCRP navigates this new reckoning associated with trauma care on the MDB, its research investments will need to be robust and enabled to plan, program, and budget for agile and closer-term solutions. To accomplish this, the program will need to expand on its strong foundation of lessons learned and assets developed over the past 20 years.


Assuntos
Pesquisa Biomédica , Medicina Militar , Lesões Relacionadas à Guerra/terapia , Humanos , Estados Unidos
19.
mBio ; 8(2)2017 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-28325763

RESUMO

While complex intra- and interspecies microbial community dynamics are apparent during chronic infections and likely alter patient health outcomes, our understanding of these interactions is currently limited. For example, Pseudomonas aeruginosa and Staphylococcus aureus are often found to coinfect the lungs of patients with cystic fibrosis (CF), yet these organisms compete under laboratory conditions. Recent observations that coinfection correlates with decreased health outcomes necessitate we develop a greater understanding of these interbacterial interactions. In this study, we tested the hypothesis that P. aeruginosa and/or S. aureus adopts phenotypes that allow coexistence during infection. We compared competitive interactions of P. aeruginosa and S. aureus isolates from mono- or coinfected CF patients employing in vitro coculture models. P. aeruginosa isolates from monoinfected patients were more competitive toward S. aureus than P. aeruginosa isolates from coinfected patients. We also observed that the least competitive P. aeruginosa isolates possessed a mucoid phenotype. Mucoidy occurs upon constitutive activation of the sigma factor AlgT/U, which regulates synthesis of the polysaccharide alginate and dozens of other secreted factors, including some previously described to kill S. aureus Here, we show that production of alginate in mucoid strains is sufficient to inhibit anti-S. aureus activity independent of activation of the AlgT regulon. Alginate reduces production of siderophores, 2-heptyl-4-hydroxyquinolone-N-oxide (HQNO), and rhamnolipids-each required for efficient killing of S. aureus These studies demonstrate alginate overproduction may be an important factor driving P. aeruginosa coinfection with S. aureusIMPORTANCE Numerous deep-sequencing studies have revealed the microbial communities present during respiratory infections in cystic fibrosis (CF) patients are diverse, complex, and dynamic. We now face the challenge of determining the influence of these community dynamics on patient health outcomes and identifying candidate targets to modulate these interactions. We make progress toward this goal by determining that the polysaccharide alginate produced by mucoid strains of P. aeruginosa is sufficient to inhibit multiple secreted antimicrobial agents produced by this organism. Importantly, these secreted factors are required to outcompete S. aureus, when the microbes are grown in coculture; thus we propose a mechanism whereby mucoid P. aeruginosa can coexist with S. aureus Finally, the approach used here can serve as a platform to investigate the interactions among other CF pathogens.


Assuntos
Alginatos/metabolismo , Coinfecção/microbiologia , Interações Microbianas , Infecções por Pseudomonas/complicações , Pseudomonas aeruginosa/crescimento & desenvolvimento , Infecções Estafilocócicas/complicações , Staphylococcus aureus/crescimento & desenvolvimento , Fibrose Cística/complicações , Ácido Glucurônico/metabolismo , Ácidos Hexurônicos/metabolismo , Humanos , Modelos Teóricos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/metabolismo , Infecções Respiratórias , Infecções Estafilocócicas/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA