Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74.952
Filtrar
1.
BMC Pulm Med ; 24(1): 172, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600466

RESUMO

BACKGROUND: Bronchiectasis is a pulmonary disease characterized by irreversible dilation of the bronchi and recurring respiratory infections. Few studies have described the microbiology and prevalence of infections in large patient populations outside of specialized tertiary care centers. METHODS: We used the Cerner HealthFacts Electronic Health Record database to characterize the nature, burden, and frequency of pulmonary infections among persons with bronchiectasis. Chronic infections were defined based on organism-specific guidelines. RESULTS: We identified 7,749 patients who met our incident bronchiectasis case definition. In this study population, the organisms with the highest rates of isolate prevalence were Pseudomonas aeruginosa with 937 (12%) individuals, Staphylococcus aureus with 502 (6%), Mycobacterium avium complex (MAC) with 336 (4%), and Aspergillus sp. with 288 (4%). Among persons with at least one isolate of each respective pathogen, 219 (23%) met criteria for chronic P. aeruginosa colonization, 74 (15%) met criteria for S. aureus chronic colonization, 101 (30%) met criteria for MAC chronic infection, and 50 (17%) met criteria for Aspergillus sp. chronic infection. Of 5,795 persons with at least two years of observation, 1,860 (32%) had a bronchiectasis exacerbation and 3,462 (60%) were hospitalized within two years of bronchiectasis diagnoses. Among patients with chronic respiratory infections, the two-year occurrence of exacerbations was 53% and for hospitalizations was 82%. CONCLUSIONS: Patients with bronchiectasis experiencing chronic respiratory infections have high rates of hospitalization.


Assuntos
Bronquiectasia , Infecções por Pseudomonas , Infecções Respiratórias , Humanos , Estados Unidos/epidemiologia , Antibacterianos/uso terapêutico , Infecção Persistente , Staphylococcus aureus , Registros Eletrônicos de Saúde , Bronquiectasia/epidemiologia , Bronquiectasia/complicações , Infecções por Pseudomonas/tratamento farmacológico , Infecções Respiratórias/complicações , Complexo Mycobacterium avium , Pseudomonas aeruginosa
2.
BMJ Case Rep ; 17(4)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38569736

RESUMO

A healthy man in his late 20s was admitted to the emergency department due to a flare-up in his severe chronic stomatitis, along with flu-like symptoms. CXR showed multiple bilateral consolidations and subsequent CT revealed thrombosis of the left facial and internal jugular vein, together with septic embolism in both lungs. Blood cultures showed penicillin-susceptible Staphylococcus aureus The patient was diagnosed with Lemierre's syndrome, despite atypical bacteria and clinical presentation. During hospitalisation, he developed pulmonary empyema as a complication and was admitted for 4 weeks. During hospitalisation and after discharge, the patient was examined for multiple rheumatic, immunological and dermatological diseases, but no underlying cause for Lemierre's syndrome has been found. We present this case due to the rarity of its nature, with atypical clinical presentation and pathogen for Lemierre's syndrome, but with classic radiological findings.


Assuntos
COVID-19 , Síndrome de Lemierre , Infecções Estafilocócicas , Masculino , Humanos , Staphylococcus aureus , Síndrome de Lemierre/complicações , Síndrome de Lemierre/tratamento farmacológico , Síndrome de Lemierre/diagnóstico , Penicilinas/uso terapêutico , COVID-19/complicações , Infecções Estafilocócicas/complicações , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/tratamento farmacológico
3.
Sci Rep ; 14(1): 9027, 2024 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-38641640

RESUMO

Copper-doped ZnO nanoparticles with the formula Zn1-x(Cu)O, where x = 0.0, 0.03, 0.05, and 0.07 were produced using the co-precipitation process. Physical, chemical, and structural properties were properly examined. Powdered X-ray diffraction (P-XRD) patterns revealed the formation of hexagonal wurtzite crystal structure in all samples, through atomic substitutional incorporation in the Cu-doped ZnO lattice. The presence of Cu ions and their dissolution in the host ZnO crystal structure was supported by FT-IR spectra. HR-TEM images were used to assess the average size, morphology, and shape regularity of the synthesized samples. The form and homogeneity of the ZnO changed when Cu ions were substituted, as evidenced by FE-SEM/EDX analysis. The presence of copper signals in the Cu-doped samples indicates that the doping was successful. The decrease in zeta potential with an increased copper doping percentage designates that the nanoparticles (NPs) are more stable, which could be attributed to an increase in the ionic strength of the aqueous solution. The synthesized NPs were evaluated for their substantial in vitro antioxidant properties. In addition, the antimicrobial efficacy of the materials was tested against pathogenic microorganisms. Regarding the anti-diabetic activity, the 7Cu ZnO sample showed the highest inhibitory effect on the α-amylase enzyme. No variations were observed in the activities of the acetylcholinesterase enzyme (AChE) and proteinase enzymes with ZnO and samples doped with different concentrations of Cu. Therefore, further studies are recommended to reveal the in-vitro anti-diabetic activity of the studied doped samples. Finally, molecular docking provided valuable insights into the potential binding interactions of Cu-doped ZnO with α-amylase, FabH of E. coli, and Penicillin-binding proteins of S. aureus. These outcomes suggest that the prepared materials may have an inhibitory effect on enzymes and hold promise in the battle against microbial infections and diabetes.


Assuntos
Óxido de Zinco , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Simulação de Acoplamento Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Cobre/química , Escherichia coli , Staphylococcus aureus , Acetilcolinesterase , Íons/farmacologia , alfa-Amilases
4.
BMC Complement Med Ther ; 24(1): 165, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38641781

RESUMO

In this study we develop novel type of antibacterial chitosan-propolis NPs to improve theantimicrobial activity against various pathogens. To this aim, we primarily extracted propolis with methylal and ethanol as green solvents and its encapsulation with chitosan NPs. The developed propolis loaded chitosan NPs indicated antimicrobial and anti-biofilm properties against various gram positive and negative. FTIR revealed the successful encapsulation of the propolis extract with Ethanol (PE) and Methylal (PM) into the chitosan nano career matrix. HPLC and GC-MASS also confirmed the presence of flavonoids and phenols compounds of propolis extracted with both solvents. In addition, we confirmed the total phenolic and flavonoid compounds in propolis by calorimetric method of Folin-Ciocalteu and aluminum trichloride complex formation assays, respectively. PE-CH and PM-CH were optimized regarding physicochemical properties such as particle size, zeta potential, and poly dispersity index (PDI) index. DLS and SEM micrographs confirmed a spherical morphology in a range of 360-420 nm with Z potential values of 30-48 mV and PDI of 0.105-0.166 for PE-CH and PM-CH, respectively. The encapsulation efficiency was evaluated using colorimetric analysis, with median values ranging from 90 to 92%. The MIC values within the range of 2 to 230 µg/ml and MBC values between 3 to 346 µg/ml against both gram-positive and negative bacteria. While both PE and PM showed a significant reduction in the number of E. coli, S. aureus, and S. epidermidis, the use of PE-CH and PM-CH led to a statistically significant and greater reduction in number of E. coli, S. aureus, and S. epidermidis strains on the biofilm, pre-formed biofilm and planktonic phases. Besides, the DPPH assay showed significant antioxidant activity for these NPs within the range of 36 to 92%. MTT assay for MHFB-1, HFF, L929, MDF, and MCF-7 cells exhibited statistically significant differences in each other that show the IC50 between 60-160 µg/ml for normal cells and 20 for cancer cells. Finally the present study indicated that both PM and PM-CH greater than PE and PE-CH in which contain high flavonoid and phenolic contents with a high antioxidation potential antioxidant properties, which could be beneficial for cell proliferation and antibiotic and anticancer applications.


Assuntos
Quitosana , Éteres Metílicos , Nanopartículas , Própole , Própole/farmacologia , Quitosana/química , Escherichia coli , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/química , Solventes , Etanol , Nanopartículas/química , Flavonoides
5.
Sci Rep ; 14(1): 9056, 2024 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-38643191

RESUMO

The impact of evolving treatment regimens, airway clearance strategies, and antibiotic combinations on the incidence and prevalence of respiratory infection in cystic fibrosis (CF) in children and adolescents remains unclear. The incidence, prevalence, and prescription trends from 2002 to 2019 with 18,339 airway samples were analysed. Staphylococcus aureus [- 3.86% (95% CI - 5.28-2.43)] showed the largest annual decline in incidence, followed by Haemophilus influenzae [- 3.46% (95% CI - 4.95-1.96)] and Pseudomonas aeruginosa [- 2.80%95% CI (- 4.26-1.34)]. Non-tuberculous mycobacteria and Burkholderia cepacia showed a non-significant increase in incidence. A similar pattern of change in prevalence was observed. No change in trend was observed in infants < 2 years of age. The mean age of the first isolation of S. aureus (p < 0.001), P. aeruginosa (p < 0.001), H. influenza (p < 0.001), Serratia marcescens (p = 0.006) and Aspergillus fumigatus (p = 0.02) have increased. Nebulised amikacin (+ 3.09 ± 2.24 prescription/year, p = 0.003) and colistin (+ 1.95 ± 0.3 prescriptions/year, p = 0.032) were increasingly prescribed, while tobramycin (- 8.46 ± 4.7 prescriptions/year, p < 0.001) showed a decrease in prescription. Dornase alfa and hypertonic saline nebulisation prescription increased by 16.74 ± 4.1 prescriptions/year and 24 ± 4.6 prescriptions/year (p < 0.001). There is a shift in CF among respiratory pathogens and prescriptions which reflects the evolution of cystic fibrosis treatment strategies over time.


Assuntos
Fibrose Cística , Pneumonia , Infecções por Pseudomonas , Criança , Lactente , Humanos , Adolescente , Fibrose Cística/complicações , Fibrose Cística/epidemiologia , Fibrose Cística/microbiologia , Staphylococcus aureus , Sistema Respiratório/microbiologia , Antibacterianos/uso terapêutico , Infecções por Pseudomonas/tratamento farmacológico , Pneumonia/tratamento farmacológico , Pseudomonas aeruginosa
6.
Cell Rep ; 43(4): 114082, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38583155

RESUMO

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are alarmingly common, and treatment is confined to last-line antibiotics. Vancomycin is the treatment of choice for MRSA bacteremia, and treatment failure is often associated with vancomycin-intermediate S. aureus isolates. The regulatory 3' UTR of the vigR mRNA contributes to vancomycin tolerance and upregulates the autolysin IsaA. Using MS2-affinity purification coupled with RNA sequencing, we find that the vigR 3' UTR also regulates dapE, a succinyl-diaminopimelate desuccinylase required for lysine and peptidoglycan synthesis, suggesting a broader role in controlling cell wall metabolism and vancomycin tolerance. Deletion of the 3' UTR increased virulence, while the isaA mutant is completely attenuated in a wax moth larvae model. Sequence and structural analyses of vigR indicated that the 3' UTR has expanded through the acquisition of Staphylococcus aureus repeat insertions that contribute sequence for the isaA interaction seed and may functionalize the 3' UTR.


Assuntos
Regiões 3' não Traduzidas , Virulência/genética , Regiões 3' não Traduzidas/genética , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Staphylococcus aureus/efeitos dos fármacos , Animais , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica , Mariposas/microbiologia , Vancomicina/farmacologia , Antibacterianos/farmacologia , Sequência de Bases
7.
Emerg Microbes Infect ; 13(1): 2341972, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38597192

RESUMO

Staphylococcus aureus (S. aureus) is a notorious pathogen that cause metastatic or complicated infections. Hypervirulent ST398 clonotype strains, remarkably increased in recent years, dominated Community-associated S. aureus (CA-SA) infections in the past decade in China. Small RNAs like RNAIII have been demonstrated to play important roles in regulating the virulence of S. aureus, however, the regulatory roles played by many of these sRNAs in the ST398 clonotype strains are still unclear. Through transcriptome screening and combined with knockout phenotype analysis, we have identified a highly transcribed sRNA, RSaX28, in the ST398 clonotype strains. Sequence analysis revealed that RSaX28 is highly conserved in the most epidemic clonotypes of S. aureus, but its high transcription level is particularly prominent in the ST398 clonotype strains. Characterization of RSaX28 through RACE and Northern blot revealed its length to be 533nt. RSaX28 is capable of promoting the hemolytic ability, reducing biofilm formation capacity, and enhancing virulence of S. aureus in the in vivo murine infection model. Through IntaRNA prediction and EMSA validation, we found that RSaX28 can specifically interact with RNAIII, promoting its stability and positively regulating the translation of downstream alpha-toxin while inhibiting the translation of Sbi, thereby regulating the virulence and biofilm formation capacity of the ST398 clonotype strains. RSaX28 is an important virulence regulatory factor in the ST398 clonotype S. aureus and represents a potential important target for future treatment and immune intervention against S. aureus infections.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Camundongos , Animais , Staphylococcus aureus/genética , Virulência/genética , RNA Bacteriano/genética , Infecções Estafilocócicas/epidemiologia , Fatores de Virulência/genética , Staphylococcus aureus Resistente à Meticilina/genética
8.
ACS Sens ; 9(4): 2156-2165, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38629405

RESUMO

Anisotropic strain sensors capable of multidirectional sensing are crucial for advanced sensor applications in human motion detection. However, current anisotropic sensors encounter challenges in achieving a balance among high sensitivity, substantial stretchability, and a wide linear detection range. To address these challenges, a facile freeze-casting strategy was employed to construct oriented filler networks composed of carbon nanotubes and conductive carbon black within a brominated butyl rubber ionomer (iBIIR) matrix. The resulting anisotropic sensor based on the iBIIR composites exhibited distinct gauge factors (GF) in the parallel and vertical directions (GF∥ = 4.91, while GF⊥ = 2.24) and a broad linear detection range over a strain range of 190%. This feature enables the sensor to detect various human activities, including uniaxial pulse, finder bending, elbow bending, and cervical spine movements. Moreover, the ion-cross-linking network within the iBIIR, coupled with strong π-cation interactions between the fillers and iBIIR macromolecules, imparted high strength (12.3 MPa, nearly twice that of pure iBIIR) and an ultrahigh elongation at break (>1800%) to the composites. Furthermore, the sensor exhibited exceptional antibacterial effectiveness, surpassing 99% against both Escherichia coli and Staphylococcus aureus. Notably, the sensor was capable of wireless sensing. It is anticipated that anisotropic sensors will have extensive application prospects in flexible wearable devices.


Assuntos
Elastômeros , Nanotubos de Carbono , Tecnologia sem Fio , Humanos , Elastômeros/química , Nanotubos de Carbono/química , Anisotropia , Dispositivos Eletrônicos Vestíveis , Fuligem/química , Movimento , Staphylococcus aureus/isolamento & purificação
9.
Front Immunol ; 15: 1373367, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38633244

RESUMO

Staphylococcus aureus is the leading cause of skin and soft tissue infections (SSTIs) in the U.S. as well as more serious invasive diseases, including bacteremia, sepsis, endocarditis, surgical site infections, osteomyelitis, and pneumonia. These infections are exacerbated by the emergence of antibiotic-resistant clinical isolates such as methicillin-resistant S. aureus (MRSA), highlighting the need for alternatives to antibiotics to treat bacterial infections. We have previously developed a multi-component toxoid vaccine (IBT-V02) in a liquid formulation with efficacy against multiple strains of Staphylococcus aureus prevalent in the industrialized world. However, liquid vaccine formulations are not compatible with the paucity of cold chain storage infrastructure in many low-to-middle income countries (LMICs). Furthermore, whether our IBT-V02 vaccine formulations are protective against S. aureus isolates from LMICs is unknown. To overcome these limitations, we developed lyophilized and spray freeze-dried formulations of IBT-V02 vaccine and demonstrated that both formulations had comparable biophysical attributes as the liquid formulation, including similar levels of toxin neutralizing antibodies and protective efficacy against MRSA infections in murine and rabbit models. To enhance the relevancy of our findings, we then performed a multi-dimensional screen of 83 S. aureus clinical isolates from LMICs (e.g., Democratic Republic of Congo, Palestine, and Cambodia) to rationally down-select strains to test in our in vivo models based on broad expression of IBT-V02 targets (i.e., pore-forming toxins and superantigens). IBT-V02 polyclonal antisera effectively neutralized toxins produced by the S. aureus clinical isolates from LMICs. Notably, the lyophilized IBT-V02 formulation exhibited significant in vivo efficacy in various preclinical infection models against the S. aureus clinical isolates from LMICs, which was comparable to our liquid formulation. Collectively, our findings suggested that lyophilization is an effective alternative to liquid vaccine formulations of our IBT-V02 vaccine against S. aureus infections, which has important implications for protection from S. aureus isolates from LMICs.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Animais , Camundongos , Coelhos , Staphylococcus aureus , Países em Desenvolvimento , Antibacterianos , Vacinas Bacterianas , Toxoides
10.
Mikrochim Acta ; 191(5): 273, 2024 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-38635063

RESUMO

Pathogenic bacteria, including drug-resistant variants such as methicillin-resistant Staphylococcus aureus (MRSA), can cause severe infections in the human body. Early detection of MRSA is essential for clinical diagnosis and proper treatment, considering the distinct therapeutic strategies for methicillin-sensitive S. aureus (MSSA) and MRSA infections. However, the similarities between MRSA and MSSA properties present a challenge in promptly and accurately distinguishing between them. This work introduces an approach to differentiate MRSA from MSSA utilizing matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) in conjunction with a neural network-based classification model. Four distinct strains of S. aureus were utilized, comprising three MSSA strains and one MRSA strain. The classification accuracy of our model ranges from ~ 92 to ~ 97% for each strain. We used deep SHapley Additive exPlanations to reveal the unique feature peaks for each bacterial strain. Furthermore, Fe3O4 MNPs were used as affinity probes for sample enrichment to eliminate the overnight culture and reduce the time in sample preparation. The limit of detection of the MNP-based affinity approach toward S. aureus combined with our machine learning strategy was as low as ~ 8 × 103 CFU mL-1. The feasibility of using the current approach for the identification of S. aureus in juice samples was also demonstrated.


Assuntos
Nanopartículas de Magnetita , Staphylococcus aureus Resistente à Meticilina , Humanos , Staphylococcus aureus , Meticilina , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Aprendizado de Máquina
11.
Medicine (Baltimore) ; 103(16): e37860, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38640320

RESUMO

Staphylococcus aureus is an important human pathogen that has a major impact on public health. The objective of the present work was to determine the prevalence and the pattern of antibiotic susceptibility in S aureus (MRSA) isolates from the King Khalid University Hospital (KKUH) in Riyadh, Saudi Arabia. The isolates were collected from different body sites of infection and the antibiotic susceptibility was confirmed on the Vitek 2 system. A total of 371 MRSA isolates from clinical samples were received over a 12-month period from January 2021 to December 2021. The results showed that infection was predominant among males (55.8%) and most of the isolates occurred in the older age groups, with a mean age of 43.7 years and an age span from <1 to 89 years old. The majority (34.5%) recovered from wound infection followed by (14.6%) from blood. We have observed peaks of MRSA infections during the autumn, especially in September and November. All MRSA isolates were resistant to Amoxicillin + clavulanic acid, Ampicillin, Imipenem, Oxacillin, Cloxacillin, and Penicillin while all isolates were sensitive to Daptomycin and Nitrofurantoin. Furthermore, Vancomycin was resistant in (0.3%) of MRSA isolates, and (2.9%) was resistant to Linezolid. The current study concluded that MRSA strains had developed resistance toward 24 tested antibiotics, including the previous effective drugs vancomycin and linezolid. Therefore, there is an urgent need for continuous review of infection control practices to prevent any further spread of resistant strains.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Masculino , Humanos , Idoso , Adulto , Lactente , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Vancomicina/farmacologia , Linezolida/farmacologia , Arábia Saudita/epidemiologia , Centros de Atenção Terciária , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Staphylococcus aureus , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Combinação Amoxicilina e Clavulanato de Potássio/farmacologia
12.
Rev Assoc Med Bras (1992) ; 70(3): e20230683, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38655992

RESUMO

OBJECTIVE: In this study, we aimed to determine the phenolic compounds, the antibacterial activity of extract from Laurus nobilis leaves, and its possible effect on transforming growth factor-ß1 expression level in peripheral blood mononuclear cells. METHODS: The phenolic components of Laurus nobilis were identified by the high-performance liquid chromatography method. The antibacterial activity of this extract was determined by disk diffusion and broth microdilution methods. The transforming growth factor-ß1 expression was analyzed using the RT-qPCR method. RESULTS: Epicatechin was found in the highest amount and o-coumaric acid in the lowest amount. The half-maximal inhibitory concentration (IC50) was determined to be 55.17 µg/mL. The zones of inhibition and minimum inhibitory concentration for Staphylococcus aureus, Enterococcus faecalis, and Klebsiella pneumoniae were 15, 14, and 8 mm and 125, 250, and 1000 µg/mL, respectively. The change in transforming growth factor-ß1 expression levels was found to be statistically significant compared with the control groups (p<0.0001). CONCLUSION: Laurus nobilis extract was found to be effective against bacteria and altered the expression level of transforming growth factor-ß1 in peripheral blood mononuclear cells.


Assuntos
Antibacterianos , Enterococcus faecalis , Laurus , Leucócitos Mononucleares , Testes de Sensibilidade Microbiana , Extratos Vegetais , Staphylococcus aureus , Fator de Crescimento Transformador beta1 , Humanos , Antibacterianos/farmacologia , Cromatografia Líquida de Alta Pressão , Enterococcus faecalis/efeitos dos fármacos , Concentração Inibidora 50 , Klebsiella pneumoniae/efeitos dos fármacos , Laurus/química , Leucócitos Mononucleares/efeitos dos fármacos , Fenóis/farmacologia , Fenóis/análise , Extratos Vegetais/farmacologia , Folhas de Planta/química , Staphylococcus aureus/efeitos dos fármacos , Fator de Crescimento Transformador beta1/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismo
13.
Nat Commun ; 15(1): 3420, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658531

RESUMO

Poly-ß-(1-6)-N-acetylglucosamine (PNAG) is an important vaccine target, expressed on many pathogens. A critical hurdle in developing PNAG based vaccine is that the impacts of the number and the position of free amine vs N-acetylation on its antigenicity are not well understood. In this work, a divergent strategy is developed to synthesize a comprehensive library of 32 PNAG pentasaccharides. This library enables the identification of PNAG sequences with specific patterns of free amines as epitopes for vaccines against Staphylococcus aureus (S. aureus), an important human pathogen. Active vaccination with the conjugate of discovered PNAG epitope with mutant bacteriophage Qß as a vaccine carrier as well as passive vaccination with diluted rabbit antisera provides mice with near complete protection against infections by S. aureus including methicillin-resistant S. aureus (MRSA). Thus, the comprehensive PNAG pentasaccharide library is an exciting tool to empower the design of next generation vaccines.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Animais , Infecções Estafilocócicas/prevenção & controle , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Camundongos , Staphylococcus aureus/imunologia , Coelhos , Vacinas Antiestafilocócicas/imunologia , Vacinas Antiestafilocócicas/administração & dosagem , Feminino , Staphylococcus aureus Resistente à Meticilina/imunologia , Acetilglucosamina/imunologia , Humanos , Epitopos/imunologia , Camundongos Endogâmicos BALB C
14.
Sci Rep ; 14(1): 9469, 2024 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658583

RESUMO

Bovine mastitis caused by S. aureus has a major economic impact on the dairy sector. With the crucial need for new therapies, anti-virulence strategies have gained attention as alternatives to antibiotics. Here we aimed to identify novel compounds that inhibit the production/activity of hemolysins, a virulence factor of S. aureus associated with mastitis severity. We screened Bacillus strains obtained from diverse sources for compounds showing anti-hemolytic activity. Our results demonstrate that lipopeptides produced by Bacillus spp. completely prevented the hemolytic activity of S. aureus at certain concentrations. Following purification, both iturins, fengycins, and surfactins were able to reduce hemolysis caused by S. aureus, with iturins showing the highest anti-hemolytic activity (up to 76% reduction). The lipopeptides showed an effect at the post-translational level. Molecular docking simulations demonstrated that these compounds can bind to hemolysin, possibly interfering with enzyme action. Lastly, molecular dynamics analysis indicated general stability of important residues for hemolysin activity as well as the presence of hydrogen bonds between iturins and these residues, with longevous interactions. Our data reveals, for the first time, an anti-hemolytic activity of lipopeptides and highlights the potential application of iturins as an anti-virulence therapy to control bovine mastitis caused by S. aureus.


Assuntos
Bacillus , Proteínas Hemolisinas , Hemólise , Lipopeptídeos , Simulação de Acoplamento Molecular , Staphylococcus aureus , Bacillus/metabolismo , Bacillus/química , Staphylococcus aureus/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Animais , Bovinos , Lipopeptídeos/farmacologia , Lipopeptídeos/química , Proteínas Hemolisinas/antagonistas & inibidores , Proteínas Hemolisinas/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Mastite Bovina/microbiologia , Mastite Bovina/tratamento farmacológico , Feminino , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/química , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Simulação de Dinâmica Molecular
15.
Sci Rep ; 14(1): 9160, 2024 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-38644387

RESUMO

Food-related illnesses have become a growing public concern due to their considerable socioeconomic and medical impacts. Vibrio parahaemolyticus and Staphylococcus aureus have been implicated as causative organisms of food-related infections and poisoning, and both can form biofilms which confer antibiotic resistance. Hence, the need for continuous search for compounds with antibiofilm and antivirulence properties. In this study, 22 iodinated hydrocarbons were screened for their antibiofilm activity, and of these, iodopropynyl butylcarbamate (IPBC) was found to effectively control biofilm formation of both pathogens with a MIC of 50 µg/mL which was bactericidal to V. parahaemolyticus and S. aureus. Microscopic studies confirmed IPBC inhibits biofilm formation of both bacteria and also disrupted their mixed biofilm formation. Furthermore, IPBC suppressed virulence activities such as motility and hemolytic activity of V. parahaemolyticus and the cell surface hydrophobicity of S. aureus. It exhibited a preservative potential against both pathogens in a shrimp model. IPBC disrupted the cell membrane of S. aureus and V. parahaemolyticus and differentially affected gene expressions related to biofilm formation and virulence. Additionally, it displayed broad-spectrum antibiofilm activities against other clinically relevant pathogens. These findings indicate IPBC offers a potential means of controlling infections mediated by Vibrio and Staphylococcus biofilms.


Assuntos
Antibacterianos , Biofilmes , Testes de Sensibilidade Microbiana , Staphylococcus aureus , Vibrio parahaemolyticus , Biofilmes/efeitos dos fármacos , Vibrio parahaemolyticus/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Antibacterianos/farmacologia , Antibacterianos/química , Animais , Virulência/efeitos dos fármacos
16.
Eur J Med Res ; 29(1): 246, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649897

RESUMO

BACKGROUND: Staphylococcus aureus is a notorious multidrug resistant pathogen prevalent in healthcare facilities worldwide. Unveiling the mechanisms underlying biofilm formation, quorum sensing and antibiotic resistance can help in developing more effective therapy for S. aureus infection. There is a scarcity of literature addressing the genetic profiles and correlations of biofilm-associated genes, quorum sensing, and antibiotic resistance among S. aureus isolates from Malaysia. METHODS: Biofilm and slime production of 68 methicillin-susceptible S. aureus (MSSA) and 54 methicillin-resistant (MRSA) isolates were determined using a a plate-based crystal violet assay and Congo Red agar method, respectively. The minimum inhibitory concentration values against 14 antibiotics were determined using VITEK® AST-GP67 cards and interpreted according to CLSI-M100 guidelines. Genetic profiling of 11 S. aureus biofilm-associated genes and agr/sar quorum sensing genes was performed using single or multiplex polymerase chain reaction (PCR) assays. RESULTS: In this study, 75.9% (n = 41) of MRSA and 83.8% (n = 57) of MSSA isolates showed strong biofilm-forming capabilities. Intermediate slime production was detected in approximately 70% of the isolates. Compared to MSSA, significantly higher resistance of clindamycin, erythromycin, and fluoroquinolones was noted among the MRSA isolates. The presence of intracellular adhesion A (icaA) gene was detected in all S. aureus isolates. All MSSA isolates harbored the laminin-binding protein (eno) gene, while all MRSA isolates harbored intracellular adhesion D (icaD), clumping factors A and B (clfA and clfB) genes. The presence of agrI and elastin-binding protein (ebpS) genes was significantly associated with biofilm production in MSSA and MRSA isolates, respectively. In addition, agrI gene was also significantly correlated with oxacillin, cefoxitin, and fluoroquinolone resistance. CONCLUSIONS: The high prevalence of biofilm and slime production among MSSA and MRSA isolates correlates well with the detection of a high prevalence of biofilm-associated genes and agr quorum sensing system. A significant association of agrI gene was found with cefoxitin, oxacillin, and fluoroquinolone resistance. A more focused approach targeting biofilm-associated and quorum sensing genes is important in developing new surveillance and treatment strategies against S. aureus biofilm infection.


Assuntos
Antibacterianos , Biofilmes , Hospitais de Ensino , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Percepção de Quorum , Staphylococcus aureus , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Percepção de Quorum/genética , Percepção de Quorum/efeitos dos fármacos , Malásia , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Antibacterianos/farmacologia , Staphylococcus aureus/genética , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Proteínas de Bactérias/genética
17.
Cells ; 13(8)2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38667271

RESUMO

Even with the best infection control protocols in place, the risk of a hospital-acquired infection of the surface of an implanted device remains significant. A bacterial biofilm can form and has the potential to escape the host immune system and develop resistance to conventional antibiotics, ultimately causing the implant to fail, seriously impacting patient well-being. Here, we demonstrate a 4 log reduction in the infection rate by the common pathogen S. aureus of 3D-printed polyaryl ether ketone (PAEK) polymeric surfaces by covalently binding the antimicrobial peptide Mel4 to the surface using plasma immersion ion implantation (PIII) treatment. The surfaces with added texture created by 3D-printed processes such as fused deposition-modelled polyether ether ketone (PEEK) and selective laser-sintered polyether ketone (PEK) can be equally well protected as conventionally manufactured materials. Unbound Mel4 in solution at relevant concentrations is non-cytotoxic to osteoblastic cell line Saos-2. Mel4 in combination with PIII aids Saos-2 cells to attach to the surface, increasing the adhesion by 88% compared to untreated materials without Mel4. A reduction in mineralisation on the Mel4-containing surfaces relative to surfaces without peptide was found, attributed to the acellular portion of mineral deposition.


Assuntos
Peptídeos Antimicrobianos , Benzofenonas , Polímeros , Impressão Tridimensional , Próteses e Implantes , Staphylococcus aureus , Humanos , Staphylococcus aureus/efeitos dos fármacos , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/química , Peptídeos Antimicrobianos/metabolismo , Próteses e Implantes/efeitos adversos , Polímeros/química , Polímeros/farmacologia , Biofilmes/efeitos dos fármacos , Cetonas/química , Cetonas/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Propriedades de Superfície , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Ortopedia
18.
Mar Drugs ; 22(4)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38667774

RESUMO

Five new biflorane-type diterpenoids, biofloranates E-I (1-5), and two new bicyclic diterpene glycosides, lemnaboursides H-I (6-7), along with the known lemnabourside, were isolated from the South China Sea soft coral Lemnalia bournei. Their chemical structures and stereochemistry were determined based on extensive spectroscopic methods, including time-dependent density functional theory (TDDFT) ECD calculations, as well as a comparison of them with the reported values. The antibacterial activities of the isolated compounds were evaluated against five pathogenic bacteria, and all of these diterpenes and diterpene glycosides showed antibacterial activities against Staphylococcus aureus and Bacillus subtilis, with MICs ranging from 4 to 64 µg/mL. In addition, these compounds did not exhibit noticeable cytotoxicities on A549, Hela, and HepG2 cancer cell lines, at 20 µM.


Assuntos
Antozoários , Antibacterianos , Bacillus subtilis , Diterpenos , Glicosídeos , Testes de Sensibilidade Microbiana , Staphylococcus aureus , Antozoários/química , Diterpenos/farmacologia , Diterpenos/química , Diterpenos/isolamento & purificação , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Animais , Glicosídeos/farmacologia , Glicosídeos/química , Glicosídeos/isolamento & purificação , Humanos , Staphylococcus aureus/efeitos dos fármacos , Bacillus subtilis/efeitos dos fármacos , Células HeLa , Linhagem Celular Tumoral , Células Hep G2 , Estrutura Molecular , Células A549 , China
19.
Mar Drugs ; 22(4)2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38667803

RESUMO

Three novel meroterpenoids, taladrimanins B-D (1-3), were isolated from the marine-derived fungus Talaromyces sp. M27416, alongside three biogenetically related compounds (4-6). We delineated taladrimanin B's (1) structure using HRESIMS and NMR, confirmed its configuration via quantum chemical NMR analysis and DP4+ methodology, and verified it through X-ray crystallography. ECD calculations determined the absolute configuration of compound 1, while comparative NMR and ECD analyses elucidated the absolute configurations of 2 and 3. These compounds are drimane-type meroterpenoids with a C10 polyketide unit (8R-configuration). We proposed a biosynthetic pathway and noted that compound 1 showed cytotoxic activity against MKN-45 and 5637 cell lines and selective antibacterial effects against Staphylococcus aureus CICC 10384.


Assuntos
Antibacterianos , Staphylococcus aureus , Talaromyces , Terpenos , Talaromyces/química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Humanos , Linhagem Celular Tumoral , Staphylococcus aureus/efeitos dos fármacos , Terpenos/farmacologia , Terpenos/química , Terpenos/isolamento & purificação , Cristalografia por Raios X , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Testes de Sensibilidade Microbiana , Organismos Aquáticos , Estrutura Molecular , Espectroscopia de Ressonância Magnética
20.
Microb Genom ; 10(4)2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38668652

RESUMO

Accurate annotation to single-nucleotide resolution of the transcribed regions in genomes is key to optimally analyse RNA-seq data, understand regulatory events and for the design of experiments. However, currently most genome annotations provided by GenBank generally lack information about untranslated regions. Additionally, information regarding genomic locations of non-coding RNAs, such as sRNAs, or anti-sense RNAs is frequently missing. To provide such information, diverse RNA-seq technologies, such as Rend-seq, have been developed and applied to many bacterial species. However, incorporating this vast amount of information into annotation files has been limited and is bioinformatically challenging, resulting in UTRs and other non-coding elements being overlooked or misrepresented. To overcome this problem, we present pyRAP (python Rend-seq Annotation Pipeline), a software package that analyses Rend-seq datasets to accurately resolve transcript boundaries genome-wide. We report the use of pyRAP to find novel transcripts, transcript isoforms, and RNase-dependent sRNA processing events. In Bacillus subtilis we uncovered 63 novel transcripts and provide genomic coordinates with single-nucleotide resolution for 2218 5'UTRs, 1864 3'UTRs and 161 non-coding RNAs. In Escherichia coli, we report 117 novel transcripts, 2429 5'UTRs, 1619 3'UTRs and 91 non-coding RNAs, and in Staphylococcus aureus, 16 novel transcripts, 664 5'UTRs, 696 3'UTRs, and 81 non-coding RNAs. Finally, we use pyRAP to produce updated annotation files for B. subtilis 168, E. coli K-12 MG1655, and S. aureus 8325 for use in the wider microbial genomics research community.


Assuntos
Bacillus subtilis , Genoma Bacteriano , Anotação de Sequência Molecular , Software , Bacillus subtilis/genética , Escherichia coli/genética , RNA Bacteriano/genética , Staphylococcus aureus/genética , Biologia Computacional/métodos , Análise de Sequência de RNA/métodos , RNA-Seq/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA