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1.
J Am Heart Assoc ; 13(15): e034027, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39101496

RESUMO

BACKGROUND: High levels of catecholamines are cardiotoxic and associated with stress-induced cardiomyopathies. Using a septic shock model that reproduces the reversible cardiomyopathy seen over 10 days associated with human septic shock, we investigated the effects of catecholamines on microcirculatory perfusion and cardiac dysfunction. METHODS AND RESULTS: Purpose-bred beagles received intrabronchial Staphylococcus aureus (n=30) or saline (n=6). The septic animals were than randomized to epinephrine (1 µg/kg per minute, n=15) or saline (n=15) infusions from 4 to 44 hours. Serial cardiac magnetic resonance imaging, catecholamine levels, and troponins were collected over 92 hours. Serial adenosine-stress perfusion cardiac magnetic resonance imaging was performed on septic animals randomized to receive saline (n=8 out of 15) or epinephrine (n=8 out of 15). High-dose sedation was given to suppress endogenous catecholamine release. Despite catecholamine levels largely remaining within the normal range throughout, by 48 hours, septic animals receiving saline versus nonseptic animals still developed significant worsening of left ventricular ejection fraction, circumferential strain, and ventricular-aortic coupling. In septic animals that received epinephrine versus saline infusions, plasma epinephrine levels increased 800-fold, but epinephrine produced no significant further worsening of left ventricular ejection fraction, circumferential strain, or ventricular-aortic coupling. Septic animals receiving saline had a significant increase in microcirculatory reserve without troponin elevations. Septic animals receiving epinephrine had decreased edema, blunted microcirculatory perfusion, and elevated troponin levels that persisted for hours after the epinephrine infusion stopped. CONCLUSIONS: Cardiac dysfunction during sepsis is not primarily due to elevated endogenous or exogenous catecholamines nor due to decreased microvascular perfusion-induced ischemia. However, epinephrine itself has potentially harmful long-lasting ischemic effects during sepsis including impaired cardiac microvascular perfusion that persists after stopping the infusion.


Assuntos
Cardiomiopatias , Modelos Animais de Doenças , Epinefrina , Microcirculação , Choque Séptico , Animais , Cães , Choque Séptico/fisiopatologia , Choque Séptico/complicações , Choque Séptico/sangue , Epinefrina/sangue , Microcirculação/efeitos dos fármacos , Cardiomiopatias/fisiopatologia , Cardiomiopatias/sangue , Cardiomiopatias/etiologia , Volume Sistólico/efeitos dos fármacos , Circulação Coronária/efeitos dos fármacos , Isquemia Miocárdica/fisiopatologia , Isquemia Miocárdica/sangue , Isquemia Miocárdica/complicações , Função Ventricular Esquerda/efeitos dos fármacos , Catecolaminas/sangue , Troponina/sangue , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/complicações , Infecções Estafilocócicas/fisiopatologia , Fatores de Tempo , Imagem de Perfusão do Miocárdio/métodos , Imageamento por Ressonância Magnética
2.
J Am Heart Assoc ; 13(15): e034026, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39101510

RESUMO

BACKGROUND: Septic shock is associated with increases in end-diastolic volume (EDV) and decreases in ejection fraction that reverse within 10 days. Nonsurvivors do not develop EDV increases. The mechanism is unknown. METHODS AND RESULTS: Purpose-bred beagles (n=33) were randomized to receive intrabronchial Staphylococcus aureus or saline. Over 96 hours, cardiac magnetic resonance imaging and echocardiograms were performed. Tissue was obtained at 66 hours. From 0 to 96 hours after bacterial challenge, septic animals versus controls had significantly increased left ventricular wall edema (6%) and wall thinning with loss of mass (15%). On histology, the major finding was nonocclusive microvascular injury with edema in myocytes, the interstitium, and endothelial cells. Edema was associated with significant worsening of biventricular ejection fractions, ventricular-arterial coupling, and circumferential strain. Early during sepsis, (0-24 hours), the EDV decreased; significantly more in nonsurvivors (ie, greater diastolic dysfunction). From 24 to 48 hours, septic animals' biventricular chamber sizes increased; in survivors significantly greater than baseline and nonsurvivors, whose EDVs were not different from baseline. Preload, afterload, or heart rate differences did not explain these differential changes. CONCLUSIONS: The cardiac dysfunction of sepsis is associated with wall edema. In nonsurvivors, at 0 to 24 hours, sepsis induces a more severe diastolic dysfunction, further decreasing chamber size. The loss of left ventricular mass with wall thinning in septic survivors may, in part, explain the EDV increases from 24 to 48 hours because of a potentially reparative process removing damaged wall tissue. Septic cardiomyopathy is most consistent with a nonocclusive microvascular injury resulting in edema causing reversible systolic and diastolic dysfunction with more severe diastolic dysfunction being associated with a decreased EDV and death.


Assuntos
Modelos Animais de Doenças , Choque Séptico , Volume Sistólico , Animais , Cães , Choque Séptico/fisiopatologia , Choque Séptico/complicações , Imageamento por Ressonância Magnética , Edema Cardíaco/fisiopatologia , Edema Cardíaco/patologia , Edema Cardíaco/diagnóstico por imagem , Função Ventricular Esquerda , Fatores de Tempo , Humanos , Infecções Estafilocócicas/complicações , Infecções Estafilocócicas/fisiopatologia , Ecocardiografia , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Masculino
3.
J Bras Pneumol ; 50(4): e20240026, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39194074

RESUMO

OBJECTIVE: Thymidine-dependent small-colony variants (TD-SCVs) of Staphylococcus aureus are being isolated with increasing frequency from patients with cystic fibrosis (CF). The aim of this study was to evaluate the relationship between TD-SCV isolation and pulmonary function in patients with CF, as well as to determine whether the emergence of TD-SCVs was associated with trimethoprim-sulfamethoxazole (TMP-SMX) use and with coinfection with other microorganisms. METHODS: This was a retrospective case-control study including patients with CF who visited the Clinical Hospital Complex of the Federal University of Paraná, in Curitiba, Brazil, between 2013 and 2022. Demographic, clinical, and spirometric data, as well as information on TD-SCVs and other isolated microorganisms, were collected from the medical records of patients with CF and TD-SCVs (TD-SCV group; n = 32) and compared with those of a matched group of patients with CF without TD-SCVs (control group; n = 64). RESULTS: Isolation of TD-SCVs was positively associated with TMP-SMX use (p = 0.009), hospitalization (p < 0.001), and impaired pulmonary function (p = 0.04). CONCLUSIONS: The use of TMP-SMX seems to contribute to the emergence of TD-SCVs, the isolation of which was directly associated with worse pulmonary function in our sample.


Assuntos
Fibrose Cística , Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Fibrose Cística/microbiologia , Fibrose Cística/fisiopatologia , Estudos Retrospectivos , Masculino , Feminino , Estudos de Casos e Controles , Staphylococcus aureus/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/fisiopatologia , Adulto , Adulto Jovem , Adolescente , Timidina/análogos & derivados , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico , Combinação Trimetoprima e Sulfametoxazol/farmacologia , Pulmão/fisiopatologia , Pulmão/microbiologia , Pulmão/efeitos dos fármacos , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Criança , Brasil , Testes de Função Respiratória
4.
Sci Adv ; 9(4): eabn0771, 2023 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-36696494

RESUMO

Drug-resistant bacterial infections have caused serious threats to human health and call for effective antibacterial agents that have low propensity to induce antimicrobial resistance. Host defense peptide-mimicking peptides are actively explored, among which poly-ß-l-lysine displays potent antibacterial activity but high cytotoxicity due to the helical structure and strong membrane disruption effect. Here, we report an effective strategy to optimize antimicrobial peptides by switching membrane disrupting to membrane penetrating and intracellular targeting by breaking the helical structure using racemic residues. Introducing ß-homo-glycine into poly-ß-lysine effectively reduces the toxicity of resulting poly-ß-peptides and affords the optimal poly-ß-peptide, ßLys50HG50, which shows potent antibacterial activity against clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) and MRSA persister cells, excellent biosafety, no antimicrobial resistance, and strong therapeutic potential in both local and systemic MRSA infections. The optimal poly-ß-peptide demonstrates strong therapeutic potential and implies the success of our approach as a generalizable strategy in designing promising antibacterial polypeptides.


Assuntos
Antibacterianos , Peptídeos Catiônicos Antimicrobianos , Permeabilidade da Membrana Celular , Farmacorresistência Bacteriana , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/fisiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/fisiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/fisiopatologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/fisiologia
5.
APMIS ; 130(2): 111-118, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34862642

RESUMO

Antibiotic prophylaxis is a key element in prevention of surgical site infections. For the majority of orthopedic procedures, antibiotic administration follows fixed dosing regimens irrespective of weight. However, this may result in insufficient antibiotic target tissue concentrations and higher risk of surgical site infections in obese individuals. The aim of this study was to investigate the effect of weight-based cefuroxime dosing on plasma and target tissue concentrations. Eighteen female pigs were allocated into three groups differentiated by weight: 53-57 kg, 73-77 kg, and 93-97 kg. Microdialysis catheters were placed for continuous sampling in bone, muscle, and subcutaneous tissue during an 8h sampling interval. Blood samples were collected as reference. Cefuroxime was administered intravenously as a bolus according to weight (20 mg/kg). The primary endpoint was the time above the cefuroxime minimal inhibitory concentration for Staphylococcus aureus (T > MIC (4 µg/mL)). Comparable target tissue T > MICs (4 µg/mL) were found between weight groups. Mean T > MIC ranged between 116-137 min for plasma, 118-154 min for bone, 109-146 min for the skeletal muscle, and 117-165 min for subcutaneous tissue across the groups. Weight-based cefuroxime (20 mg/kg) dosing approach provides comparable perioperative plasma and target tissue T > MIC (4 µg/mL) in animals between 50-100 kg body weight, and thus a comparable prophylaxis of surgical site infections.


Assuntos
Antibacterianos/administração & dosagem , Cefuroxima/administração & dosagem , Infecções Estafilocócicas/prevenção & controle , Infecção da Ferida Cirúrgica/prevenção & controle , Animais , Antibacterianos/análise , Antibioticoprofilaxia , Peso Corporal , Esquema de Medicação , Cálculos da Dosagem de Medicamento , Feminino , Humanos , Microdiálise , Procedimentos Ortopédicos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Tela Subcutânea/efeitos dos fármacos , Infecção da Ferida Cirúrgica/microbiologia , Infecção da Ferida Cirúrgica/fisiopatologia , Suínos
6.
JCI Insight ; 6(21)2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34747366

RESUMO

Superficial cutaneous Staphylococcus aureus (S. aureus) infection in humans can lead to soft tissue infection, an important cause of morbidity and mortality. IL-17A production by skin TCRγδ+ cells in response to IL-1 and IL-23 produced by epithelial and immune cells is important for restraining S. aureus skin infection. How S. aureus evades this cutaneous innate immune response to establish infection is not clear. Here we show that mechanical injury of mouse skin by tape stripping predisposed mice to superficial skin infection with S. aureus. Topical application of S. aureus to tape-stripped skin caused cutaneous influx of basophils and increased Il4 expression. This basophil-derived IL-4 inhibited cutaneous IL-17A production by TCRγδ+ cells and promoted S. aureus infection of tape-stripped skin. We demonstrate that IL-4 acted on multiple checkpoints that suppress the cutaneous IL-17A response. It reduced Il1 and Il23 expression by keratinocytes, inhibited IL-1+IL-23-driven IL-17A production by TCRγδ+ cells, and impaired IL-17A-driven induction of neutrophil-attracting chemokines by keratinocytes. IL-4 receptor blockade is shown to promote Il17a expression and enhance bacterial clearance in tape-stripped mouse skin exposed to S. aureus, suggesting that it could serve as a therapeutic approach to prevent skin and soft tissue infection.


Assuntos
Basófilos/metabolismo , Interleucina-4/efeitos adversos , Infecções Estafilocócicas/imunologia , Infecções Cutâneas Estafilocócicas/imunologia , Animais , Humanos , Imunidade Inata , Camundongos , Infecções Estafilocócicas/fisiopatologia , Infecções Cutâneas Estafilocócicas/fisiopatologia
7.
Eur J Clin Microbiol Infect Dis ; 40(12): 2563-2574, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34312744

RESUMO

The ability of Staphylococcus aureus to form biofilms is an important virulence factor. During the infectious process, the interaction between biofilms and immune cells is determinant; however, the properties that make biofilms resistant to the immune system are not well characterized. In order to better understand this, we evaluated the in vitro interaction of macrophages during the early stages of S. aureus biofilm formation. Biofilm formation was evaluated by crystal violet staining, light microscopy, and confocal scanning laser microscopy. Furthermore, different activation on L-arginine pathways such as nitric oxide (NO•) release and the arginase, the production of reactive oxygen species (ROS), the total oxidative stress response (OSR), and levels of cytokine liberation, were determined. Our findings show that the interaction between biofilms and macrophages results in stimuli for catabolism of L-arginine via arginase, but not for NO•, an increase of ROS production, and activation of the non-enzymatic OSR. We also observed the production of IL-6, but not of TNFα o IL-10 in these co-cultures. These results contribute to a better understanding of host-pathogen interactions and suggest that biofilms increase resistance against immune cell mechanisms, a phenomenon that could contribute to the ability of S. aureus biofilms to establish mature biofilms.


Assuntos
Biofilmes , Macrófagos/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/fisiologia , Técnicas de Cocultura , Interações Hospedeiro-Patógeno , Humanos , Interleucina-6/metabolismo , Macrófagos/imunologia , Espécies Reativas de Oxigênio/metabolismo , Infecções Estafilocócicas/metabolismo , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/genética
8.
Elife ; 102021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34227939

RESUMO

The normal wound healing process is characterised by proteolytic events, whereas infection results in dysfunctional activations by endogenous and bacterial proteases. Peptides, downstream reporters of these proteolytic actions, could therefore serve as a promising tool for diagnosis of wounds. Using mass-spectrometry analyses, we here for the first time characterise the peptidome of human wound fluids. Sterile post-surgical wound fluids were found to contain a high degree of peptides in comparison to human plasma. Analyses of the peptidome from uninfected healing wounds and Staphylococcus aureus -infected wounds identify unique peptide patterns of various proteins, including coagulation and complement factors, proteases, and antiproteinases. Together, the work defines a workflow for analysis of peptides derived from wound fluids and demonstrates a proof-of-concept that such fluids can be used for analysis of qualitative differences of peptide patterns from larger patient cohorts, providing potential biomarkers for wound healing and infection.


Infected wounds and burns represent a serious risk to patients: they can delay healing and, if left untreated, can lead to generalised infection or sepsis, organ failure and death. Wounds and burns get infected when harmful micro-organisms, such as bacteria, enter the wound. Predicting the risk of infections, and detecting them early, could reduce their impact and make treating them easier. A way to distinguish between healing and infected wounds is to study how proteins are broken down in each situation. Proteases are the enzymes that break down proteins, and they are different in healing wounds and infected wounds that are failing to heal. This is because, while the body produces proteases, the bacteria that cause infection do so too. Each protease breaks down proteins in a specific way, resulting in a different set of protein fragments, known as peptides. Together, all the peptides in a wound are referred to as the wound's 'peptidome'. Studying the peptidome of a wound could show whether it is infected, and even what type of bacteria might be responsible, which could help identify suitable treatments. Van der Plas et al. used a technique called mass spectrometry to study the peptidome of wounds after surgery. Sterile post-surgical wounds showed high levels of peptides compared to plasma, the liquid component of blood, with up to 4,300 different peptides. Comparing healing wounds to ones infected with the bacterium Staphylococcus aureus revealed that infected wounds contained peptides from about 150 proteins not found in uninfected wounds, while peptides from 90 proteins were unique to uninfected wounds. The peptides exclusive to uninfected wounds included some linked to antimicrobial activity and immune system activity. Van der Plas et al.'s results suggest that analysing the peptidome may be an approach to tracking the healing status of wounds, making it easier to detect infection before symptoms are apparent. The next step will be to study more wounds and identify the reliable peptide markers to use them for diagnostic tests.


Assuntos
Líquidos Corporais/metabolismo , Espectrometria de Massas/métodos , Fragmentos de Peptídeos/análise , Proteômica/métodos , Infecções Estafilocócicas/fisiopatologia , Cicatrização/fisiologia , Humanos , Peso Molecular , Staphylococcus aureus/fisiologia
9.
Adv Skin Wound Care ; 34(7): 365-370, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34125726

RESUMO

OBJECTIVE: To explore the features and risk factors of bacterial skin infections (BSIs) in hospitalized patients with bullous pemphigoid (BP). METHODS: Records were retrospectively reviewed for 110 hospitalized patients with BP admitted to Peking University First Hospital between 2013 and 2019. Bacterial species and drug resistance were assessed, and then the underlying risk factors for BSIs were evaluated. RESULTS: Infections were present in 40% (44/110) of the patients. Staphylococcus aureus (72.7%, 32/44) was the most common bacterium, and it was highly resistant to penicillin (81.3%, 26/32), erythromycin (62.5%, 20/32), and clindamycin (56.3%, 18/32), but 100.0% sensitive to vancomycin and tigecycline. Coronary heart disease (P = .02; odds ratio [OR], 12.68), multisystem comorbidities (P = .02; OR, 3.67), hypoalbuminemia (P = .04; OR, 3.70), high levels of anti-BP180 antibodies (>112.4 U/mL; P = .003; OR, 6.43), and season (spring: reference; summer: P = .002; OR, 23.58; autumn: P = .02; OR, 12.19; winter: P = .02; OR, 13.19) were significantly associated with BSIs. CONCLUSIONS: Hospitalized patients with BP had a high incidence of BSIs, and those patients with underlying risk factors require careful management to prevent and control BSIs.


Assuntos
Penfigoide Bolhoso/complicações , Infecções dos Tecidos Moles/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Penfigoide Bolhoso/epidemiologia , Estudos Retrospectivos , Dermatopatias Bacterianas/epidemiologia , Dermatopatias Bacterianas/etiologia , Infecções dos Tecidos Moles/epidemiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/etiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/patogenicidade
11.
Angew Chem Int Ed Engl ; 60(32): 17714-17719, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34028150

RESUMO

A lipid named DCPA was synthesized under microwave-assisted heating. DCPA possesses a pyridine betaine, hydrophilic group that can be complexed with water through hydrogen bonding (DCPA-H2 O). DCPA-H2 O liposomes became protonated relatively fast already at pH<6.8, due to the high HOMO binding energy of DCPA-H2 O. In murine models, DCPA-H2 O liposomes had longer blood circulation times than natural DPPC or cationic DCPM liposomes, while after tail-vein injection DCPA-H2 O liposomes targeted faster to solid tumors and intra-abdominal infectious biofilms. Therapeutic efficacy in a murine, infected wound-healing model of tail-vein injected ciprofloxacin-loaded DCPA-H2 O liposomes exceeded the ones of clinically applied ciprofloxacin as well as of ciprofloxacin-loaded DPPC or DCPM liposomes.


Assuntos
Portadores de Fármacos/farmacocinética , Lipossomos/farmacocinética , Neoplasias/diagnóstico por imagem , Infecções Estafilocócicas/diagnóstico por imagem , Água/química , Acetatos/síntese química , Acetatos/farmacocinética , Animais , Antibacterianos/uso terapêutico , Biofilmes , Ciprofloxacina/uso terapêutico , Portadores de Fármacos/síntese química , Feminino , Corantes Fluorescentes/química , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Lipossomos/química , Masculino , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/fisiologia , Compostos de Piridínio/síntese química , Compostos de Piridínio/farmacocinética , Ratos Sprague-Dawley , Rodaminas/química , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Tuberculose/diagnóstico por imagem , Tuberculose/fisiopatologia
12.
Commun Biol ; 4(1): 432, 2021 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-33785850

RESUMO

Despite being a major bacterial factor in alerting the human immune system, the role of Staphylococcus aureus (S. aureus) lipoproteins (Lpp) in skin infections remains largely unknown. Here, we demonstrated that subcutaneous injection of S. aureus Lpp led to infiltration of neutrophils and monocytes/macrophages and induced skin lesions in mice. Lipid-moiety of S. aureus Lpp and host TLR2 was responsible for such effect. Lpp-deficient S. aureus strains exhibited smaller lesion size and reduced bacterial loads than their parental strains; the altered phenotype in bacterial loads was TLR2-independent. Lpp expression in skin infections contributed to imbalanced local hemostasis toward hypercoagulable state. Depletion of leukocytes or fibrinogen abrogated the effects induced by Lpp in terms of skin lesions and bacterial burden. Our data suggest that S. aureus Lpp induce skin inflammation and promote abscess formation that protects bacteria from innate immune killing. This suggests an intriguing bacterial immune evasion mechanism.


Assuntos
Abscesso/fisiopatologia , Proteínas de Bactérias/fisiologia , Lipoproteínas/fisiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/fisiologia , Abscesso/microbiologia , Animais , Feminino , Camundongos , Infecções Estafilocócicas/microbiologia
13.
Amino Acids ; 53(2): 313-317, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33576904

RESUMO

The effects of ΔPb-CATH4, a cathelicidin derived from Python bivittatus, were evaluated against Staphylococcus aureus-infected wounds in mice. These effects were comparable to those of classical antibiotics. ΔPb-CATH4 was resistant to bacterial protease but not to porcine trypsin. A reduction in the level of inflammatory cytokines and an increase in the migration of immune cells was observed in vitro. Thus, ΔPb-CATH4 can promote wound healing by controlling infections including those caused by multidrug-resistant bacteria via its immunomodulatory effects.


Assuntos
Catelicidinas/administração & dosagem , Infecções Estafilocócicas/tratamento farmacológico , Infecção dos Ferimentos/tratamento farmacológico , Animais , Boidae , Catelicidinas/química , Humanos , Camundongos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/fisiologia , Cicatrização/efeitos dos fármacos , Infecção dos Ferimentos/microbiologia , Infecção dos Ferimentos/fisiopatologia
14.
J Thromb Thrombolysis ; 51(3): 821-826, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32749620

RESUMO

Infective endocarditis (IE) remains a severe illness with high mortality rate, despite advances in antibiotic therapy and cardiac surgery. If infectious bacteria and platelets are two key players of human IE vegetation developmental process, their interactions and respective roles in fully developed late-stage IE vegetations remain obscure. The objective of this study was to better understand the organization of the different components of the IE vegetation and to provide a detailed description of this vegetation ultrastructure. A late stage Staphylococcal endocarditic vegetation was provided from a 13 years teenager patient. After reception of the surgical piece, we carried out a histological study using routine methods, notably the hematoxylin-eosin-saffron staining. Labeling with the anti-CD 61 antibody was also carried out. In a second step, we used transmission electron microscopy to describe the different regions making up the vegetation. Our ultrastructural study revealed vegetation was clearly composed by three different regions and identified the specific location of the bacteria and platelets in the vegetation tissues. Histological analysis showed that platelets and Staphylococcus aureus were not co-localized. Electron microscopy study confirmed that S. aureus were found at distance from platelets, as well from immune cells, embedded in a biofilm and/or a necrotic area. These results reveal a development of a deep bacteria-only niche in vegetation, raising questions about medication access to these microorganisms. Vegetation composed of three regions: a region rich in bacteria incorporated into the necrotic tissue, the second region composed of fibrin filaments and the third region rich in platelets and free of bacteria.


Assuntos
Insuficiência da Valva Aórtica , Valva Aórtica , Endocardite Bacteriana , Implante de Prótese de Valva Cardíaca/métodos , Infecções Estafilocócicas , Staphylococcus aureus/isolamento & purificação , Adolescente , Antibacterianos/administração & dosagem , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/imunologia , Valva Aórtica/microbiologia , Valva Aórtica/patologia , Insuficiência da Valva Aórtica/diagnóstico , Insuficiência da Valva Aórtica/etiologia , Insuficiência da Valva Aórtica/fisiopatologia , Insuficiência da Valva Aórtica/cirurgia , Plaquetas/patologia , Ecocardiografia/métodos , Endocardite Bacteriana/sangue , Endocardite Bacteriana/microbiologia , Endocardite Bacteriana/patologia , Humanos , Imuno-Histoquímica , Masculino , Microscopia Eletrônica de Transmissão/métodos , Infecções Estafilocócicas/sangue , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/fisiopatologia , Resultado do Tratamento
15.
J Dairy Sci ; 104(1): 899-914, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33189263

RESUMO

We conducted a longitudinal study to evaluate the effect of non-aureus staphylococci (NAS) causing subclinical intramammary infections (IMI) on quarter milk somatic cell count (qSCC) and quarter milk yield (qMY). In total, 324 quarters of 82 Holstein Friesian heifers were followed from calving to 130 d in milk (DIM) and were sampled 10 times each at 14-d intervals. The IMI status of each quarter was determined based on bacterial culture results at the current and previous or next sampling day, or both. The qSCC was determined on each sampling day and the average qMY on sampling day was available through stored daily milk weight data in the management program of the automatic milking system. A transient IMI (tIMI) was defined as a case where a specific pathogen was isolated from a quarter on only one sampling day and not on the previous or next sampling day. When the same bacterial strain, as defined by random amplification of polymorphic DNA-PCR, was isolated from the same quarter on multiple sampling days, it was defined as a persistent IMI (pIMI) status on those sampling days; a pIMI episode was defined as the combination of multiple consecutive pIMI statuses with the same bacterial strain on different sampling days. During this study, 142 subclinical IMI with NAS occurred in 116 different quarters from 64 animals, yielding in total 304 NAS isolates belonging to 17 different species. The prevalence of NAS was highest in the first 4 DIM. Overall, the predominant species was Staphylococcus chromogenes (52% of the isolates), followed by S. epidermidis (9.2%), S. xylosus (8.2%), and S. equorum (5.9%). Staphylococcus chromogenes was the only species for which an effect on qSCC and qMY could be analyzed separately; the other NAS species were considered as a group because of their low prevalence. Eighteen out of 40 IMI (45%) caused by S. chromogenes persisted over at least 2 sampling days, whereas only 10 of 102 (9.8%) IMI caused by other NAS species persisted for at least 2 sampling days. The average duration of pIMI episodes was 110.4 d for S. chromogenes and 70 d for the other NAS species. Remarkably, 17 of the 18 pIMI episodes with S. chromogenes started within the first 18 DIM. The qSCC was highest in quarters having a pIMI with a major pathogen, followed by quarters having a pIMI with S. chromogenes, and a pIMI with other NAS. Transient IMI with other NAS or with a major pathogen caused a small but significantly higher qSCC, whereas the qSCC in quarters having a tIMI with S. chromogenes was not statistically different compared with noninfected quarters. No significant differences in qMY were observed between quarters having a pIMI or tIMI with S. chromogenes or with the other NAS species compared with noninfected quarters, despite the higher qSCC. Quarters having a pIMI with major pathogens showed significantly lower daily milk production. Surprisingly, quarters that cured from an IMI with S. chromogenes had a significantly lower qMY than noninfected quarters.


Assuntos
Glândulas Mamárias Animais/microbiologia , Mastite Bovina/microbiologia , Mastite Bovina/fisiopatologia , Infecções Estafilocócicas/veterinária , Animais , Bovinos , Contagem de Células/veterinária , Feminino , Estudos Longitudinais , Glândulas Mamárias Animais/fisiopatologia , Mastite Bovina/epidemiologia , Leite/citologia , Gravidez , Complicações Infecciosas na Gravidez/microbiologia , Complicações Infecciosas na Gravidez/fisiopatologia , Complicações Infecciosas na Gravidez/veterinária , Prevalência , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Staphylococcus epidermidis/isolamento & purificação
16.
Pediatr Pulmonol ; 56(2): 442-449, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33219628

RESUMO

BACKGROUND: Cystic fibrosis transmembrane conductance regulator (CFTR) gating mutations (GMs) result in CFTR that is present at the cell surface but nonfunctional. Patients with the G551D mutation, the most prevalent worldwide, have been well studied. Italian GM patients have mainly non-G551D mutations. We studied their epidemiology and clinical characteristics in the period spanning the pre/post ivacaftor introduction to the Italian market. METHODS: Data from the Italian CF Registry were used to describe patients with GMs and compare them with F508del homozygous (F/F) patients. RESULTS: In total, 186 patients with GMs (median [range] age, 21.96 [0.13-63.38] years) were identified among the 5552 patients included in the study (3.3%). They had lower sweat chloride values at diagnosis than the F/F and a lower ratio of males. In the GM group, examining the data of the years 2012 and 2017 and comparing with F/F, lung infection by Staphylococcus aureus and diabetes became less prevalent, and better FEV1 and nutritional status were observed in 2017. The cross-sectional evaluation year-by-year from 2012 to 2017 of the GM group showed improving trends in lung function and body mass index, and the decreasing prevalence of diabetes compared with F/F. Longitudinal evaluation of GM patients showed improvement in percent predicted (pp)FEV1 and nutrition in the 2012-2017 period. These variations correspond to the introduction of treatment with the CFTR potentiator ivacaftor (2014/2015). CONCLUSIONS: Italian patients with GMs are few and are characterized by milder phenotypes than F/F patients. Improved outcomes are likely influenced by treatment with ivacaftor.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/genética , Adolescente , Adulto , Aminofenóis/uso terapêutico , Índice de Massa Corporal , Criança , Pré-Escolar , Agonistas dos Canais de Cloreto/uso terapêutico , Cloretos/análise , Fibrose Cística/tratamento farmacológico , Fibrose Cística/epidemiologia , Fibrose Cística/fisiopatologia , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/genética , Diabetes Mellitus/fisiopatologia , Feminino , Volume Expiratório Forçado , Humanos , Lactente , Itália , Masculino , Pessoa de Meia-Idade , Mutação , Quinolonas/uso terapêutico , Sistema de Registros , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/genética , Infecções Estafilocócicas/fisiopatologia , Suor/química , Adulto Jovem
17.
mBio ; 11(6)2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33323513

RESUMO

The opportunistic human pathogen Staphylococcus aureus causes serious infectious diseases that range from superficial skin and soft tissue infections to necrotizing pneumonia and sepsis. While classically regarded as an extracellular pathogen, S. aureus is able to invade and survive within human cells. Host cell exit is associated with cell death, tissue destruction, and the spread of infection. The exact molecular mechanism employed by S. aureus to escape the host cell is still unclear. In this study, we performed a genome-wide small hairpin RNA (shRNA) screen and identified the calcium signaling pathway as being involved in intracellular infection. S. aureus induced a massive cytosolic Ca2+ increase in epithelial host cells after invasion and intracellular replication of the pathogen. This was paralleled by a decrease in endoplasmic reticulum Ca2+ concentration. Additionally, calcium ions from the extracellular space contributed to the cytosolic Ca2+ increase. As a consequence, we observed that the cytoplasmic Ca2+ rise led to an increase in mitochondrial Ca2+ concentration, the activation of calpains and caspases, and eventually to cell lysis of S. aureus-infected cells. Our study therefore suggests that intracellular S. aureus disturbs the host cell Ca2+ homeostasis and induces cytoplasmic Ca2+ overload, which results in both apoptotic and necrotic cell death in parallel or succession.IMPORTANCE Despite being regarded as an extracellular bacterium, the pathogen Staphylococcus aureus can invade and survive within human cells. The intracellular niche is considered a hideout from the host immune system and antibiotic treatment and allows bacterial proliferation. Subsequently, the intracellular bacterium induces host cell death, which may facilitate the spread of infection and tissue destruction. So far, host cell factors exploited by intracellular S. aureus to promote cell death are only poorly characterized. We performed a genome-wide screen and found the calcium signaling pathway to play a role in S. aureus invasion and cytotoxicity. The intracellular bacterium induces a cytoplasmic and mitochondrial Ca2+ overload, which results in host cell death. Thus, this study first showed how an intracellular bacterium perturbs the host cell Ca2+ homeostasis.


Assuntos
Cálcio/metabolismo , Infecções Estafilocócicas/metabolismo , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/fisiologia , Apoptose , Morte Celular , Citoplasma/metabolismo , Retículo Endoplasmático/metabolismo , Células HeLa , Homeostase , Interações Hospedeiro-Patógeno , Humanos , Viabilidade Microbiana , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/crescimento & desenvolvimento
18.
Chest ; 158(5): e221-e224, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33160540

RESUMO

A 40-year-old woman with lymphangiomatosis also had an intrathoracic lymphangioma infection. Since the age of 8 years, the patient had undergone repeated abdominal and mediastinal cyst surgeries and had received a diagnosis of lymphangiomatosis. At this time, she showed a high fever of 38.5°C. Cultures of both blood and fluid aspirated from the cyst were positive for Staphylococcus aureus. Chest CT imaging revealed an enlarged right-sided mediastinal cystic lymphangioma with new septa in it. A chest tube was inserted into the cyst to remove effusion. The patient was then started with the antibacterial drug cefazolin at 3 g/d. But effective drainage was difficult because of the high viscosity of the effusion and septa working as barriers. We removed these components with endoscopic surgical instruments and via a pulsed-lavage system under general anesthesia. Postoperative CT images showed reexpanded lung structure and reduced cyst size. The patient has taken a favorable course for 2 years.


Assuntos
Cefazolina/administração & dosagem , Desbridamento/métodos , Drenagem/métodos , Linfangioma , Neoplasias do Mediastino , Infecções Estafilocócicas , Adulto , Antibacterianos/administração & dosagem , Endoscopia/métodos , Feminino , Humanos , Linfangioma/microbiologia , Linfangioma/patologia , Linfangioma/fisiopatologia , Linfangioma/terapia , Neoplasias do Mediastino/microbiologia , Neoplasias do Mediastino/patologia , Neoplasias do Mediastino/fisiopatologia , Neoplasias do Mediastino/terapia , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/fisiopatologia , Infecções Estafilocócicas/cirurgia , Staphylococcus aureus/isolamento & purificação , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
20.
Crit Care Med ; 48(11): 1645-1653, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32947475

RESUMO

OBJECTIVES: We recently found that distinct body temperature trajectories of infected patients correlated with survival. Understanding the relationship between the temperature trajectories and the host immune response to infection could allow us to immunophenotype patients at the bedside using temperature. The objective was to identify whether temperature trajectories have consistent associations with specific cytokine responses in two distinct cohorts of infected patients. DESIGN: Prospective observational study. SETTING: Large academic medical center between 2013 and 2019. SUBJECTS: Two cohorts of infected patients: 1) patients in the ICU with septic shock and 2) hospitalized patients with Staphylococcus aureus bacteremia. INTERVENTIONS: Clinical data (including body temperature) and plasma cytokine concentrations were measured. Patients were classified into four temperature trajectory subphenotypes using their temperature measurements in the first 72 hours from the onset of infection. Log-transformed cytokine levels were standardized to the mean and compared with the subphenotypes in both cohorts. MEASUREMENTS AND MAIN RESULTS: The cohorts consisted of 120 patients with septic shock (cohort 1) and 88 patients with S. aureus bacteremia (cohort 2). Patients from both cohorts were classified into one of four previously validated temperature subphenotypes: "hyperthermic, slow resolvers" (n = 19 cohort 1; n = 13 cohort 2), "hyperthermic, fast resolvers" (n = 18 C1; n = 24 C2), "normothermic" (n = 54 C1; n = 31 C2), and "hypothermic" (n = 29 C1; n = 20 C2). Both "hyperthermic, slow resolvers" and "hyperthermic, fast resolvers" had high levels of G-CSF, CCL2, and interleukin-10 compared with the "hypothermic" group when controlling for cohort and timing of cytokine measurement (p < 0.05). In contrast to the "hyperthermic, slow resolvers," the "hyperthermic, fast resolvers" showed significant decreases in the levels of several cytokines over a 24-hour period, including interleukin-1RA, interleukin-6, interleukin-8, G-CSF, and M-CSF (p < 0.001). CONCLUSIONS: Temperature trajectory subphenotypes are associated with consistent cytokine profiles in two distinct cohorts of infected patients. These subphenotypes could play a role in the bedside identification of cytokine profiles in patients with sepsis.


Assuntos
Temperatura Corporal/fisiologia , Imunidade/imunologia , Sepse/imunologia , Idoso , Bacteriemia/imunologia , Bacteriemia/fisiopatologia , Temperatura Corporal/imunologia , Citocinas/sangue , Feminino , Febre/imunologia , Febre/fisiopatologia , Humanos , Imunidade/fisiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sepse/fisiopatologia , Choque Séptico/imunologia , Choque Séptico/fisiopatologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/fisiopatologia
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