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1.
Nature ; 579(7798): 260-264, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32132711

RESUMO

The production of pore-forming toxins that disrupt the plasma membrane of host cells is a common virulence strategy for bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA)1-3. It is unclear, however, whether host species possess innate immune mechanisms that can neutralize pore-forming toxins during infection. We previously showed that the autophagy protein ATG16L1 is necessary for protection against MRSA strains encoding α-toxin4-a pore-forming toxin that binds the metalloprotease ADAM10 on the surface of a broad range of target cells and tissues2,5,6. Autophagy typically involves the targeting of cytosolic material to the lysosome for degradation. Here we demonstrate that ATG16L1 and other ATG proteins mediate protection against α-toxin through the release of ADAM10 on exosomes-extracellular vesicles of endosomal origin. Bacterial DNA and CpG DNA induce the secretion of ADAM10-bearing exosomes from human cells as well as in mice. Transferred exosomes protect host cells in vitro by serving as scavengers that can bind multiple toxins, and improve the survival of mice infected with MRSA in vivo. These findings indicate that ATG proteins mediate a previously unknown form of defence in response to infection, facilitating the release of exosomes that serve as decoys for bacterially produced toxins.


Assuntos
Proteínas Relacionadas à Autofagia/metabolismo , Toxinas Bacterianas/metabolismo , Exossomos/metabolismo , Células A549 , Proteína ADAM10/metabolismo , Animais , Toxinas Bacterianas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , DNA Bacteriano/farmacologia , Exossomos/efeitos dos fármacos , Exossomos/ultraestrutura , Feminino , Células HEK293 , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Staphylococcus aureus Resistente à Meticilina/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Infecções Estafilocócicas/mortalidade
2.
R I Med J (2013) ; 103(2): 18-20, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32122094

RESUMO

Hospital antibiograms, because they are typically derived from samples obtained from hospitalized patients, may overestimate the prevalence of methicillin resistance in S. aureus in individuals presenting to the hospital for surgery. Because hospital antibiograms are commonly used to justify empiric perioperative prophylactic antibiotic selection prior to surgery, this may lead to unnecessary treatment with broad-spectrum antibiotics such as vancomycin. In a single-institution study, we observed that in our hospital antibiogram the proportion of S. aureus that are methicillin-resistant (MRSA) was significantly higher (45%) than isolates in preoperative nasal cultures obtained at the same hospital in outpatients prior to their lower extremity joint replacement surgery (13%): mean difference 0.32, [95% CI 0.25, 0.39], p <0.0001. These data suggest that hospital antibiograms may overstate the true prevalence of MRSA in those at risk for MRSA surgical site infections who present from the outpatient setting.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/microbiologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Cavidade Nasal/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/isolamento & purificação , Adulto , Antibacterianos/uso terapêutico , Portador Sadio/epidemiologia , Feminino , Humanos , Masculino , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Período Pré-Operatório , Prevalência , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/efeitos dos fármacos
3.
Artigo em Inglês | MEDLINE | ID: mdl-32178604

RESUMO

From 1 January to 31 December 2018, thirty-six institutions around Australia participated in the Australian Staphylococcus aureus Sepsis Outcome Programme (ASSOP). The aim of ASSOP 2018 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that are antimicrobial resistant, with particular emphasis on susceptibility to methicillin, and to characterise the molecular epidemiology of the methicillin-resistant isolates. A total of 2,673 S. aureus bacteraemia episodes were reported, of which 78.9% were community-onset. A total of 17.4% of S. aureus isolates were methicillin resistant. The 30-day all-cause mortality associated with methicillin-resistant SAB was 17.1% which was not significantly higher than the 13.6% mortality associated with methicillin-susceptible SAB (p = 0.1). With the exception of the ß-lactams and erythromycin, antimicrobial resistance in methicillin-susceptible S. aureus was rare. However in addition to the ß-lactams approximately 42% of methicillin-resistant S. aureus (MRSA) were resistant to erythromycin, 36% to ciprofloxacin and approximately 13% resistant to co-trimoxazole, tetracycline and gentamicin. When applying the EUCAST breakpoints teicoplanin resistance was detected in two S. aureus isolates. Resistance was not detected for vancomycin and linezolid. Resistance to non-beta-lactam antimicrobials was largely attributable to two healthcare-associated MRSA clones: ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA). The ST22-IV [2B] (EMRSA-15) clone is the predominant healthcare-associated clone in Australia. Seventy-eight percent of methicillin-resistant SAB episodes in 2018 were due to community-associated clones. Although polyclonal, approximately 76.3% of community-associated clones were characterised as ST93-IV [2B] (Queensland CA-MRSA), ST5-IV [2B], ST45-VT [5C2&5], ST1-IV [2B], ST30-IV [2B], ST78-IV [2B] and ST97-IV [2B]. Community-associated MRSA, in particular the ST45-VT [5C2&5] clone, has acquired multiple antimicrobial resistance determinants including ciprofloxacin, erythromycin, clindamycin, gentamicin and tetracycline. The ST45-VT [5C2&5] clone accounted for 11.7% of CA-MRSA. As CA-MRSA is well established in the Australian community, it is important that antimicrobial resistance patterns in community- and healthcare-associated SAB are monitored, as this information will guide therapeutic practices in treating S. aureus sepsis.


Assuntos
Antibacterianos , Staphylococcus aureus Resistente à Meticilina , Sepse , Infecções Estafilocócicas , Staphylococcus aureus , Antibacterianos/farmacologia , Austrália/epidemiologia , Bacteriemia , Infecção Hospitalar/tratamento farmacológico , Farmacorresistência Bacteriana/efeitos dos fármacos , Humanos , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Sepse/tratamento farmacológico , Sepse/etiologia , Infecções Estafilocócicas/complicações , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos
4.
JAMA ; 323(6): 527-537, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-32044943

RESUMO

Importance: Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is associated with mortality of more than 20%. Combining standard therapy with a ß-lactam antibiotic has been associated with reduced mortality, although adequately powered randomized clinical trials of this intervention have not been conducted. Objective: To determine whether combining an antistaphylococcal ß-lactam with standard therapy is more effective than standard therapy alone in patients with MRSA bacteremia. Design, Setting, and Participants: Open-label, randomized clinical trial conducted at 27 hospital sites in 4 countries from August 2015 to July 2018 among 352 hospitalized adults with MRSA bacteremia. Follow-up was complete on October 23, 2018. Interventions: Participants were randomized to standard therapy (intravenous vancomycin or daptomycin) plus an antistaphylococcal ß-lactam (intravenous flucloxacillin, cloxacillin, or cefazolin) (n = 174) or standard therapy alone (n = 178). Total duration of therapy was determined by treating clinicians and the ß-lactam was administered for 7 days. Main Outcomes and Measures: The primary end point was a 90-day composite of mortality, persistent bacteremia at day 5, microbiological relapse, and microbiological treatment failure. Secondary outcomes included mortality at days 14, 42, and 90; persistent bacteremia at days 2 and 5; acute kidney injury (AKI); microbiological relapse; microbiological treatment failure; and duration of intravenous antibiotics. Results: The data and safety monitoring board recommended early termination of the study prior to enrollment of 440 patients because of safety. Among 352 patients randomized (mean age, 62.2 [SD, 17.7] years; 121 women [34.4%]), 345 (98%) completed the trial. The primary end point was met by 59 (35%) with combination therapy and 68 (39%) with standard therapy (absolute difference, -4.2%; 95% CI, -14.3% to 6.0%). Seven of 9 prespecified secondary end points showed no significant difference. For the combination therapy vs standard therapy groups, all-cause 90-day mortality occurred in 35 (21%) vs 28 (16%) (difference, 4.5%; 95% CI, -3.7% to 12.7%); persistent bacteremia at day 5 was observed in 19 of 166 (11%) vs 35 of 172 (20%) (difference, -8.9%; 95% CI, -16.6% to -1.2%); and, excluding patients receiving dialysis at baseline, AKI occurred in 34 of 145 (23%) vs 9 of 145 (6%) (difference, 17.2%; 95% CI, 9.3%-25.2%). Conclusions and Relevance: Among patients with MRSA bacteremia, addition of an antistaphylococcal ß-lactam to standard antibiotic therapy with vancomycin or daptomycin did not result in significant improvement in the primary composite end point of mortality, persistent bacteremia, relapse, or treatment failure. Early trial termination for safety concerns and the possibility that the study was underpowered to detect clinically important differences in favor of the intervention should be considered when interpreting the findings. Trial Registration: ClinicalTrials.gov Identifier: NCT02365493.


Assuntos
Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Daptomicina/uso terapêutico , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas/tratamento farmacológico , Vancomicina/uso terapêutico , beta-Lactamas/uso terapêutico , Adulto , Idoso , Antibacterianos/efeitos adversos , Bacteriemia/microbiologia , Bacteriemia/mortalidade , Cefazolina/uso terapêutico , Cloxacilina/uso terapêutico , Quimioterapia Combinada , Endocardite Bacteriana/tratamento farmacológico , Feminino , Floxacilina/uso terapêutico , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/mortalidade , Falha de Tratamento , beta-Lactamas/efeitos adversos
5.
Medicine (Baltimore) ; 99(8): e19283, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32080142

RESUMO

Surgical site infection (SSI) can be a devastating complication in joint arthroplasty. Objective of this study was to identify potential risk factors associated with SSI following primary joint arthroplasty.This retrospective cohort study was performed from January 2016 to October 2017. A total of 986 patients were enrolled. We extracted the patients' baseline information, treatment-related variables and indexes of laboratory examination during their hospitalization. Receiver operating characteristic (ROC) analysis was performed to find the optimum cut-off value for serum albumin. Univariate and multivariate logistic analysis models were performed respectively to determine independent predictors of SSI.Nine hundred eighty-six patients with complete data were included in the final analysis. There were 314 male and 672 females in this study with a mean age of 64.6 years, and twenty patients developed SSI. The overall incidence of SSI was 2.03%, with 0.20% for deep infection and 1.83% for superficial SSI. Independent predictors of SSI identified by multivariate analysis were ALB < 36.7 g/L (odds ratio = 3.42; 95% CI = 1.24-9.48; P = .018), BMI ≥28 (odds ratio = 5.08; 95%CI = 1.52-17.01; P = .008) and ASA class 3 or higher (odds ratio = 3.36; 95% CI = 1.22-9.30; P = .019). Drain use was demonstrated as a protective factor of postoperative wound healing.The incidence of SSI following primary joint arthroplasty was 2.03%. ASA ≥3, BMI ≥28 and ALB < 36.7 g/L were demonstrated as risk factors of postoperative wound infection. Supplementary nutrition support is necessary to reduce the risk of infection in patients who underwent artificial joint arthroplasty.


Assuntos
Artroplastia de Substituição/efeitos adversos , Infecção da Ferida Cirúrgica/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , China/epidemiologia , Estudos de Coortes , Drenagem , Feminino , Globulinas/análise , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Complicações Pós-Operatórias , Prognóstico , Infecções por Pseudomonas/epidemiologia , Pseudomonas aeruginosa/isolamento & purificação , Estudos Retrospectivos , Fatores de Risco , Albumina Sérica/análise , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/isolamento & purificação , Infecção da Ferida Cirúrgica/microbiologia , Adulto Jovem
6.
J Med Microbiol ; 69(2): 290-297, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32004137

RESUMO

Introduction. Staphylococcus aureus is a recognised cause of foodborne intoxication and antibiotic-associated diarrhoea (AAD), which are both mediated by staphylococcal enterotoxins. However, unlike foodborne intoxication, AAD appears to require infection of the host. While S. aureus intoxication is widely studied, little is known about S. aureus pathogenesis in the context of gastrointestinal infection.Aim. To develop a mouse model of S. aureus gastrointestinal infection.Methodology. An established AAD mouse model was adapted for S. aureus infection, and damage observed via histopathological analysis and immunostaining of intestinal tissues.Results. Various strains colonised the mouse model, and analysis showed that although clinical signs of disease were not seen, S. aureus infection induced damage in the small intestine, disrupting host structures essential for epithelial integrity. Studies using a staphylococcal enterotoxin B mutant showed that this toxin may contribute to damage during gastrointestinal infection.Conclusion. This work presents a new mouse model of S. aureus gastrointestinal infection, while also providing insight into the pathogenesis of S. aureus in the gut.


Assuntos
Intestino Delgado/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/fisiologia , Animais , Modelos Animais de Doenças , Enterotoxinas/genética , Enterotoxinas/metabolismo , Enterotoxinas/toxicidade , Fezes/microbiologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Staphylococcus aureus/genética
8.
Int J Antimicrob Agents ; 55(3): 105890, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923572

RESUMO

The involvement of platelets in anti-infectious immunity has been widely demonstrated. Molecules secreted mainly by α-granules are involved in reducing the growth of certain bacterial species. However, the effect of antiplatelet treatments on the platelet antibacterial ability remains poorly understood. This study aimed to evaluate the platelet antibacterial effect against Staphylococcus aureus and to evaluate the influence of antiplatelet drugs on this effect. Blood samples were collected from healthy donors or patients treated with antiplatelet therapy. Six S. aureus strains were included. Bacteria were incubated with platelets for 4 h. Colonies were counted on blood agar. The supernatant's effect was evaluated. The effect of in vitro antiplatelet agents and salicylic acid was also tested. The CD62P expression rate was evaluated under different conditions of infection and platelet treatment. Platelets slowed the growth of the six S. aureus strains (P = 0.006 for P6134, P = 0.001 for P6170 and P6138, and P = 0.003 for the other strains versus bacteria alone). The supernatant of platelets pre-infected with bacteria and that of platelets pre-treated with TRAP retained this antibacterial effect (platelet-bacteria supernatant, P = 0.018; TRAP, P = 0.011 versus bacteria alone). Treatment of platelets by antiplatelet drugs significantly decreased this antibacterial effect (aspirin, P = 0.027; ticagrelor, P = 0.0263; combination, P = 0.0092 versus untreated platelets). Salicylic acid also induced inhibition of this antibacterial effect (P = 0.042 versus untreated platelets). This study showed that antiplatelet agents decreased the antibacterial effect of platelets against S. aureus.


Assuntos
Plaquetas/efeitos dos fármacos , Inibidores da Agregação de Plaquetas/farmacologia , Infecções Estafilocócicas/sangue , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Plaquetas/imunologia , Plaquetas/metabolismo , Células Cultivadas , Humanos , Inibidores da Agregação de Plaquetas/uso terapêutico
10.
BMC Infect Dis ; 20(1): 6, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900118

RESUMO

BACKGROUND: An efficient surface cleaning strategy would first target cleaning to surfaces that make large contributions to the risk of infections. METHODS: In this study, we used data from the literature about methicillin-resistant Staphylococcus aureus (MRSA) and developed an ordinary differential equations based mathematical model to quantify the impact of contact heterogeneity on MRSA transmission in a hypothetical 6-bed intensive care unit (ICU). The susceptible patients are divided into two types, these who are cared by the same nurse as the MRSA infected patient (Type 1) and these who are not (Type 2). RESULTS: The results showed that the mean MRSA concentration on three kinds of susceptible patient nearby surfaces was significantly linearly associated with the hand-touch frequency (p < 0.05). The noncompliance of daily cleaning on patient nearby high-touch surfaces (HTSs) had the most impact on MRSA transmission. If the HTSs were not cleaned, the MRSA exposure to Type 1 and 2 susceptible patients would increase 118.4% (standard deviation (SD): 33.0%) and 115.4% (SD: 30.5%) respectively. The communal surfaces (CSs) had the least impact, if CSs were not cleaned, the MRSA exposure to Type 1 susceptible patient would only increase 1.7% (SD: 1.3). The impact of clinical equipment (CE) differed largely for two types of susceptible patients. If the CE was not cleaned, the exposure to Type 1 patients would only increase 8.4% (SD: 3.0%), while for Type 2 patients, it can increase 70.4% (SD: 25.4%). CONCLUSIONS: This study provided a framework to study the pathogen concentration dynamics on environmental surfaces and quantitatively showed the importance of cleaning patient nearby HTSs on controlling the nosocomial infection transmission via contact route.


Assuntos
Busca de Comunicante/métodos , Unidades de Terapia Intensiva , Staphylococcus aureus Resistente à Meticilina/fisiologia , Modelos Teóricos , Infecções Estafilocócicas/transmissão , Busca de Comunicante/estatística & dados numéricos , Infecção Hospitalar/transmissão , Detergentes/farmacologia , Desinfecção , Feminino , Higiene das Mãos/estatística & dados numéricos , Humanos , Controle de Infecções/métodos , Transmissão de Doença Infecciosa do Paciente para o Profissional/estatística & dados numéricos , Transmissão de Doença Infecciosa do Profissional para o Paciente/estatística & dados numéricos , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Resistência a Meticilina/fisiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Propriedades de Superfície
11.
BMC Infect Dis ; 20(1): 24, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31914949

RESUMO

BACKGROUND: Despite recent improvement in management, infective endocarditis (IE) continues to be associated with considerable risk of morbidity and mortality. Early identification of predictors of inpatient mortality is key in improving patient outcomes in IE. The aim of our study was to evaluate the role of serum troponin levels measurements as a marker of increased mortality. METHODS: A case-control study included adult patients with IE admitted to a tertiary care hospital in east Tennessee between December 2012 and July 2017. Cases were defined as patients with definitive IE who died in-hospital; controls were patients who did not die in hospital. First patient admission was included only. Data collected included the patients' demographic and baseline clinical information, microbiological data, injection drug use status, elevated serum troponins levels. RESULTS: Two hundred eighty three patients with definitive IE were included; median (IQR) age was 41 (30-57) years, and 153 (54%) patients were men. One-hundred sixty-four (58%) were injection drug users. The most frequent IE type was: 167 (59%) right-sided, 86 (30%) left-sided, 24 (9%) both left and right-sided, and 10 (4%) device related. The most commonly isolated organism was Staphylococcus aureus (n = 141), and 64% were methicillin-resistant. Two-hundred twelve (75%) patients had a troponin level obtained, and 57 (27%) had an elevated troponin value. Thirty-six (13%) patients died in-hospital; in-hospital mortality was associated elevated troponin values (adjusted odds ratio [adjOR], 7.3; 95%CI, 3.3-15.9), and methicillin-resistant S. aureus IE (adjOR 2.6; 95%CI, 1.2-5.8). Forty-four (16%) patients received IE valve surgery, and none of these patients died in the hospital. CONCLUSION: Inpatient mortality was higher in patients with IE and elevated cardiac troponin levels compared to patients with normal levels.


Assuntos
Endocardite/diagnóstico , Endocardite/mortalidade , Mortalidade Hospitalar , Troponina/sangue , Adulto , Idoso , Estudos de Casos e Controles , Usuários de Drogas/estatística & dados numéricos , Endocardite/microbiologia , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/microbiologia , Endocardite Bacteriana/mortalidade , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/mortalidade , Abuso de Substâncias por Via Intravenosa/diagnóstico , Abuso de Substâncias por Via Intravenosa/microbiologia , Abuso de Substâncias por Via Intravenosa/mortalidade , Tennessee/epidemiologia , Estados Unidos/epidemiologia
12.
Anal Bioanal Chem ; 412(4): 871-880, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31901958

RESUMO

Novel carbon dots (CDs) were synthesized by a one-pot hydrothermal approach using ampicillin as a precursor, and the as-prepared CDs exhibited a high quantum yield (23%). The CDs were found to possess abundant surface functional groups, thus providing good permeability to the cell, and the antibacterial activity of CDs was evaluated. S. aureus and L. monocytogenes were selected as model bacteria, and our results showed that the CDs exhibited antibacterial activity against S. aureus and L. monocytogenes under visible light illumination, even at low concentrations. The antibacterial mechanism is believed to be the production of reactive oxygen species (ROS) from CDs under visible light irradiation, which attacked the bacterial cell membranes, resulting in the death of the bacteria. In addition, because of the multicolor fluorescence properties of CDs, staining of S. aureus and L. monocytogenes obtained multicolor fluorescence images at different excitation wavelengths. Based on these results, CDs are a promising candidate material for biological applications. Graphical abstract.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Carbono/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Ampicilina/análogos & derivados , Ampicilina/síntese química , Antibacterianos/síntese química , Antibacterianos/química , Carbono/química , Humanos , Listeriose/tratamento farmacológico , Nanopartículas/química , Infecções Estafilocócicas/tratamento farmacológico
13.
Sports Health ; 12(1): 51-57, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31660785

RESUMO

BACKGROUND: Athletic training rooms have a high prevalence of bacteria, including multidrug-resistant organisms, increasing the risk for both local and systematic infections in athletes. There are limited data outlining formal protocols or standardized programs to reduce bacterial and viral burden in training rooms as a means of decreasing infection rate at the collegiate and high school levels. HYPOTHESIS: Adaptation of a hygiene protocol would lead to a reduction in bacterial and viral pathogen counts in athletic training rooms. STUDY DESIGN: Cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: Two high school and 2 collegiate athletic training rooms were studied over the course of the 2017-2018 academic year. A 3-phase protocol, including introduction of disinfectant products followed by student-athlete and athletic trainer education, was implemented at the 4 schools. Multiple surfaces in the athletic training rooms were swabbed at 4 time points throughout the investigation. Bacterial and viral burden from swabs were analyzed for overall bacterial aerobic plate count (APC), bacterial adenosine triphosphate activity, influenza viral load, and multidrug-resistant organisms such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE). RESULTS: Overall bacterial load, as measured by APC, was reduced by 94.7% (95% CI, 72.6-99.0; P = 0.003) over the course of the investigation after protocol implementation. MRSA and VRE were found on 24% of surfaces prior to intervention and were reduced to 0% by the end of the study. Influenza was initially detected on 25% of surfaces, with no detection after intervention. No cases of athletic training room-acquired infections were reported during the study period. CONCLUSION: A uniform infection control protocol was effective in reducing bacterial and viral burden, including multidrug-resistant organisms, when implemented in the athletic training rooms of 2 high schools and 2 colleges. CLINICAL RELEVANCE: A standardized infection control protocol can be utilized in athletic training rooms to reduce bacterial and viral burden.


Assuntos
Infecções Comunitárias Adquiridas/prevenção & controle , Reservatórios de Doenças/microbiologia , Controle de Infecções/métodos , Instituições Acadêmicas , Infecções Comunitárias Adquiridas/transmissão , Desinfetantes/administração & dosagem , Infecções por Bactérias Gram-Positivas/prevenção & controle , Infecções por Bactérias Gram-Positivas/transmissão , Desinfecção das Mãos , Educação em Saúde , Humanos , Influenza Humana/prevenção & controle , Influenza Humana/transmissão , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Orthomyxoviridae/isolamento & purificação , Comportamento de Redução do Risco , Infecções Estafilocócicas/prevenção & controle , Infecções Estafilocócicas/transmissão , Enterococos Resistentes à Vancomicina/isolamento & purificação
14.
Infect Immun ; 88(2)2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31740526

RESUMO

The staphylococcal accessory regulator (sarA) plays an important role in Staphylococcus aureus infections, including osteomyelitis, and the msaABCR operon has been implicated as an important factor in modulating expression of sarA Thus, we investigated the contribution of msaABCR to sarA-associated phenotypes in the S. aureus clinical isolates LAC and UAMS-1. Mutation of msaABCR resulted in reduced production of SarA and a reduced capacity to form a biofilm in both strains. Biofilm formation was enhanced in a LAC msa mutant by restoring the production of SarA, but this was not true in a UAMS-1 msa mutant. Similarly, extracellular protease production was increased in a LAC msa mutant but not a UAMS-1 msa mutant. This difference was reflected in the accumulation and distribution of secreted virulence factors and in the impact of extracellular proteases on biofilm formation in a LAC msa mutant. Most importantly, it was reflected in the relative impact of mutating msa as assessed in a murine osteomyelitis model, which had a significant impact in LAC but not in UAMS-1. In contrast, mutation of sarA had a greater impact on all of these in vitro and in vivo phenotypes than mutation of msaABCR, and it did so in both LAC and UAMS-1. These results suggest that, at least in osteomyelitis, it would be therapeutically preferable to target sarA rather than msaABCR to achieve the desired clinical result, particularly in the context of divergent clinical isolates of S. aureus.


Assuntos
Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Fenótipo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/fisiologia , Fatores de Virulência/metabolismo , Animais , Proteínas de Bactérias/genética , Biofilmes/crescimento & desenvolvimento , Modelos Animais de Doenças , Genótipo , Camundongos Endogâmicos C57BL , Mutação , Osteomielite/microbiologia , Osteomielite/patologia , Staphylococcus aureus/classificação , Fatores de Virulência/genética
15.
Infect Immun ; 88(2)2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31740530

RESUMO

While investigating the virulence traits of Staphylococcus aureus adhering to the skin of atopic-dermatitis (AD) patients, we identified a novel open reading frame (ORF) with structural similarity to a superantigen from genome sequence data of an isolate from AD skin. Concurrently, the same ORF was identified in a bovine isolate of S. aureus and designated SElY (H. K. Ono, Y. Sato'o, K. Narita, I. Naito, et al., Appl Environ Microbiol 81:7034-7040, 2015, https://doi.org/10.1128/AEM.01873-15). Recombinant SElYbov had superantigen activity in human peripheral blood mononuclear cells. It further demonstrated emetic activity in a primate animal model, and it was proposed that SElY be renamed SEY (H. K. Ono, S. Hirose, K. Narita, M. Sugiyama, et al., PLoS Pathog 15:e1007803, 2019, https://doi.org/10.1371/journal.ppat.1007803). Here, we investigated the prevalence of the sey gene in 270 human clinical isolates of various origins in Japan. Forty-two strains were positive for the sey gene, and the positive isolates were from patients with the skin diseases atopic dermatitis and impetigo/staphylococcal scalded skin syndrome (SSSS), with a detection rate of ∼17 to 22%. There were three variants of SEY (SEY1, SEY2, and SEY3), and isolates producing SEY variants formed three distinct clusters corresponding to clonal complexes (CCs) 121, 59, and 20, respectively. Most sey + isolates produced SEY in broth culture. Unlike SEYbov, the three recombinant SEY variants exhibited stability against heat treatment. SEY predominantly activated human T cells with a particular T-cell receptor (TCR) Vα profile, a unique observation since most staphylococcal enterotoxins exert their superantigenic activities through activating T cells with specific TCR Vß profiles. SEY may act to induce localized inflammation via skin-resident T-cell activation, facilitating the pathogenesis of S. aureus infection in disrupted epithelial barriers.


Assuntos
Proliferação de Células , Dermatite Atópica/complicações , Enterotoxinas/imunologia , Receptores de Antígenos de Linfócitos T/análise , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Subpopulações de Linfócitos T/imunologia , Análise por Conglomerados , Enterotoxinas/análise , Enterotoxinas/genética , Genótipo , Humanos , Japão , Tipagem Molecular , Pele/microbiologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Staphylococcus aureus/imunologia , Subpopulações de Linfócitos T/química
16.
J Med Microbiol ; 69(1): 41-45, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31789588

RESUMO

Introduction. Vancomycin has become the first-line therapy for most infections caused by methicillin-resistant staphylococci.Aim. To evaluate the vancomycin MIC, staphylococcal cassette chromosome mec (SCCmec) types and clonality of coagulase-negative staphylococci (CoNS) isolates recovered from neonates with true primary bloodstream infections (BSI).Methodology. CoNS isolates were prospectively recovered from blood cultures of non-repetitive patients admitted to a neonatal intensive care unit (NICU) in a tertiary-care hospital during a 3-year period. BSI was defined based on established criteria. Micro-organisms were identified phenotypically and by PCR. MIC-values for vancomycin and oxacillin were determined by broth dilution method and E-test. The SCCmec type conferring methicillin resistance was determined by multiplex PCR. The heterogeneous vancomycin (hV) resistance phenotype was screened on brain heart infusion agar containing 4 µg ml-1 of vancomycin. The clonality was investigated by PFGE.Results. Seventy-four CoNS isolates were recovered from blood cultures of neonates during the study period but only 40 (54 %) were associated with true primary BSI. Nine (22.5%) babies died. Staphylococcus epidermidis was the most prevalent species (95 %; 38/40). All S. epidermidis isolates were methicillin-resistant (MR). SCCmec type IV was predominant (55.3 %; 21/38). Most (80.0 %; 32/38) isolates exhibited vancomycin MIC-values of 2-4 µg ml-1 not associated with the SCCmec type or clonality. Sixteen (42.1%) isolates displayed hV resistance. All babies who died were harbouring MR-S. epidermidis exhibiting vancomycin MICs of 2-4 µg ml-1.Conclusion. The findings of this study demonstrated that blood invasive MR-S. epidermidis isolates recovered at NICU tend to show decreased vancomycin susceptibility making therapy of those fragile patients difficult.


Assuntos
Resistência a Meticilina/genética , Meticilina/farmacologia , Staphylococcus epidermidis/efeitos dos fármacos , Antibacterianos/farmacologia , Bacteriemia/tratamento farmacológico , Suscetibilidade a Doenças , Farmacorresistência Bacteriana/genética , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Terapia Intensiva Neonatal , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Sepse/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus/efeitos dos fármacos , Staphylococcus/isolamento & purificação , Staphylococcus epidermidis/isolamento & purificação , Staphylococcus epidermidis/metabolismo , Vancomicina/farmacologia , Resistência a Vancomicina/genética
17.
Arch Microbiol ; 202(1): 115-125, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31501949

RESUMO

Staphylococcus aureus is part of the normal flora of animals, and represents one of the leading causes of contagious mastitis in dairy herds worldwide. Sixty-seven epidemiologically unrelated S. aureus isolates from nasal and mastitis milk samples of dairy-producing animals (32 cows, 25 sheep, and 10 goats) were characterized by antimicrobial susceptibility testing and spa typing followed by multilocus sequence typing (MLST) on representative isolates and SCCmec-typing on methicillin-resistant S. aureus (MRSA) isolates. The highest resistance was observed to penicillin (64.2%, 43/67), followed by tetracycline (23.9%, 16/67), erythromycin (22.4%, 15/67), and streptomycin (17.9%, 12/67). In general, 18 spa types (including newly identified t16958) and 13 sequence types (STs) belonging to 8 clonal complexes (CCs) were detected. The cow-associated isolates were mainly assigned to CC5 (n = 18, related to t267-ST97, t521-ST352, t527-ST97, t304-ST6, and t084-ST15), followed by CC398 (n = 6, t937-ST291), CC45 (n = 3, t230-ST45), CC88 (n = 2, t2526-ST88), CC22 (n = 2, t3680-ST22), and CC522 (n = 1, t3576-ST522). Small ruminant isolates were mostly clustered into CC522 (n = 29, related to t3576, t1534, t16958, t7308, t7311, t7305 [ST522], t1534-ST2057, and t5428-ST2079). Two isolates from cows with mastitis were found to be MRSA, exhibited a composite profile of t937-ST291-SCCmecIV. No isolates carried the PVL and mecC genes. A significant difference in clonal types of S. aureus isolates from cows in comparison with those from small ruminants was found. This study demonstrated the circulation of diverse clones of S. aureus among dairy animals in Iran, with a different clonal composition between cows and small ruminants. The current study also reports MRSA-related mastitis in dairy cows, emphasizing the need for comprehensive surveillance.


Assuntos
Antibacterianos/farmacologia , Genótipo , Testes de Sensibilidade Microbiana/veterinária , Ruminantes/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/efeitos dos fármacos , Animais , Bovinos , Indústria de Laticínios , Farmacorresistência Bacteriana/efeitos dos fármacos , Feminino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Tipagem de Sequências Multilocus , Ovinos , Infecções Estafilocócicas/microbiologia
18.
World Neurosurg ; 133: e303-e307, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31520754

RESUMO

OBJECTIVE: To explore the safety and efficacy of hydrogen peroxide H2O2 in controlling blood loss and surgical site infection (SSI) after multisegmental lumbar spine surgery. METHODS: A total of 2626 patients who had undergone multisegmental lumbar spinal surgery from January 2015 to January 2018 were included in the present study. Stratified by the use of H2O2 irrigation, they were divided into 2 groups: the control group (n = 1345) and the experimental group (n = 1281). The demographic parameters, laboratory examination results, and surgery-related information (e.g., operative time, number of operated levels, intraoperative blood loss, postoperative drainage, postoperative SSI, extubation time), and perioperative complications were recorded. RESULTS: No significant differences were seen regarding the demographic parameters, laboratory examination results, comorbidities, and surgery-related information. The extubation time and postoperative drainage collection were lower in the experimental group (3.6 ± 0.5 vs. 4.1 ± 0.6 days, P = 0.402; 251.8 ± 67.5 vs. 291.8 ± 71.3 mL, P = 0.013). In the control group, the rate of SSI was 2.4% (32 of 1345) and included 17 superficial wound infections and 15 deep wound infections. In the experimental group, the SSI rate was 1.4% (18 of 1281; 15 with a superficial wound infection and 3 with a deep wound infection). Staphylococcus aureus was the most common organism, especially in the experimental group (66.7% vs. 50%). No statistically significant difference was found between the 2 groups in the perioperative complications, including hematencephalon, deep vein thrombosis, pulmonary embolism, and myocardial infarction (P > 0.05). Pneumocephalus was not observed in either group. CONCLUSION: The application of H2O2 in posterior lumbar interbody fusion can reduce the blood loss and incidence of SSI after surgery and was quite beneficial for controlling the increasing number of vancomycin-resistant bacteria.


Assuntos
Anti-Infecciosos Locais/uso terapêutico , Perda Sanguínea Cirúrgica/prevenção & controle , Hemostasia Cirúrgica/métodos , Peróxido de Hidrogênio/uso terapêutico , Vértebras Lombares/cirurgia , Fusão Vertebral , Infecção da Ferida Cirúrgica/prevenção & controle , Idoso , Antibacterianos/uso terapêutico , Anti-Infecciosos Locais/administração & dosagem , Antibioticoprofilaxia , Estudos de Casos e Controles , Feminino , Humanos , Peróxido de Hidrogênio/administração & dosagem , Masculino , Pessoa de Meia-Idade , Pré-Medicação , Estudos Retrospectivos , Infecções Estafilocócicas/prevenção & controle , Irrigação Terapêutica
20.
Biosci Biotechnol Biochem ; 84(1): 143-153, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31549575

RESUMO

Brevinin-GR23 (B-GR23) was a brevinin-2 like antimicrobial peptide, which had antimicrobial activity against Staphylococcus aureus with minimum inhibitory concentration (MIC) of 16 µM. B-GR23 increased the bacterial membrane permeation, leading to the damage of membrane integrity and the leakage of genomic DNA, then causing the cell death. The peptide nearly inhibited all plantonic bacteria to start the initial attachment of biofilm at the concentration of 1 × MIC. Whereas the disruption rates on immature and mature biofilm decreased from 60% to 20%. B-GR23 reduced the production of extracellular polysaccharides (EPS) in the planktonic growth of S. aureus, which is a crucial structure of biofilm formation. B-GR23 with the concentration of ½ × MIC inhibited 50% water-soluble EPS, and 48% water-insoluble EPS, which contributed to the antibiofilm activity. B-GR23 had no significant toxicity to human blood cells under-tested concentration (200 µM), making it a potential template for designing antimicrobial peptides.


Assuntos
Proteínas de Anfíbios/farmacologia , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Biofilmes/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Animais , Antibacterianos/síntese química , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/química , Permeabilidade da Membrana Celular/efeitos dos fármacos , DNA Bacteriano/efeitos dos fármacos , DNA Bacteriano/metabolismo , Eritrócitos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana/métodos , Polissacarídeos Bacterianos/antagonistas & inibidores , Conformação Proteica em alfa-Hélice , Estabilidade Proteica/efeitos da radiação , Ranidae , Infecções Estafilocócicas/tratamento farmacológico
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