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1.
Int J Nanomedicine ; 16: 1929-1942, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33727807

RESUMO

Background: Staphylococcus aureus biofilms pose a unique challenge in healthcare due to their tolerance to a wide range of antimicrobial agents. The high cost and lengthy timeline to develop novel therapeutic agents have pushed researchers to investigate the use of nanomaterials to deliver antibiofilm agents and target biofilm infections more efficiently. Previous studies have concentrated on improving the efficacy of antibiotics by deploying nanoparticles as nanocarriers. However, the dispersal of the extracellular polymeric substance (EPS) matrix in biofilm-associated infections is also critical to the development of novel nanoparticle-based therapies. Methods: This study evaluated the efficacy of enzyme-functionalized mesoporous silica nanoparticles (MSNs) against methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) biofilms. MSNs were functionalized with the enzyme lysostaphin, which causes cell lysis of S. aureus bacteria. This was combined with two other enzyme functionalized MSNs, serrapeptase and DNase I which will degrade protein and eDNA in the EPS matrix, to enhance eradication of the biofilm. Cell viability after treatment with enzyme-functionalized MSNs was assessed using a MTT assay and CLSM, while crystal violet staining was used to assess EPS removal. Results: The efficacy of all three enzymes against S. aureus cells and biofilms was significantly improved when they were immobilized onto MSNs. Treatment efficacy was further enhanced when the three enzymes were used in combination against both MRSA and MSSA. Regardless of biofilm maturity (24 or 48 h), near-complete dispersal and killing of MRSA biofilms were observed after treatment with the enzyme-functionalized MSNs. Disruption of mature MSSA biofilms with a polysaccharide EPS was less efficient, but cell viability was significantly reduced. Conclusion: The combination of these three enzymes and their functionalization onto nanoparticles might extend the therapeutic options for the treatment of S. aureus infections, particularly those with a biofilm component.


Assuntos
Biofilmes/crescimento & desenvolvimento , Enzimas/metabolismo , Nanopartículas/química , Dióxido de Silício/química , Staphylococcus aureus/fisiologia , Biomassa , Sobrevivência Celular , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Humanos , Staphylococcus aureus Resistente à Meticilina/fisiologia , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Porosidade
2.
Molecules ; 26(4)2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33669637

RESUMO

Antimicrobial bioassay-guided fractionation of the endophytic fungi Neofusicoccum australe led to the isolation of a new unsymmetrical naphthoquinone dimer, neofusnaphthoquinone B (1), along with four known natural products (2-5). Structure elucidation was conducted by nuclear magnetic resonance (NMR) spectroscopic methods, and the antimicrobial activity of all the natural products was investigated, revealing 1 to be moderately active towards methicillin-resistant Staphylococcus aureus (MRSA) with a minimum inhibitory concentration (MIC) of 16 µg/mL.


Assuntos
Antibacterianos/farmacologia , Ascomicetos/química , Endófitos/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antifúngicos/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Morte Celular/efeitos dos fármacos , Dimerização , Escherichia coli/efeitos dos fármacos , Células HEK293 , Humanos , Testes de Sensibilidade Microbiana , Naftoquinonas/química , Naftoquinonas/farmacologia , Espectroscopia de Prótons por Ressonância Magnética
3.
Molecules ; 26(4)2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33669881

RESUMO

Ruta chalepensis L. (Rutaceae), a perennial herb with wild and cultivated habitats, is well known for its traditional uses as an anti-inflammatory, analgesic, antipyretic agent, and in the treatment of rheumatism, nerve diseases, neuralgia, dropsy, convulsions and mental disorders. The antimicrobial activities of the crude extracts from the fruits, leaves, stem and roots of R. chalepensis were initially evaluated against two Gram-positive and two Gram-negative bacterial strains and a strain of the fungus Candida albicans. Phytochemical investigation afforded 19 compounds, including alkaloids, coumarins, flavonoid glycosides, a cinnamic acid derivative and a long-chain alkane. These compounds were tested against a panel of methicillin-resistant Staphylococcus aureus (MRSA) strains, i.e., ATCC 25923, SA-1199B, XU212, MRSA-274819 and EMRSA-15. The MIC values of the active compounds, chalepin (9), chalepensin (10), rutamarin (11), rutin 3'-methyl ether (14), rutin 7,4'-dimethyl ether (15), 6-hydroxy-rutin 3',7-dimethyl ether (16) and arborinine (18) were in the range of 32-128 µg/mL against the tested MRSA strains. Compounds 10 and 16 were the most active compounds from R. chalepensis, and were active against four out of six tested MRSA strains, and in silico studies were performed on these compounds. The anti-MRSA activity of compound 16 was comparable to that of the positive control norfloxacin (MICs 32 vs 16 µg/mL, respectively) against the MRSA strain XU212, which is a Kuwaiti hospital isolate that possesses the TetK tetracycline efflux pump. This is the first report on the anti-MRSA property of compounds isolated from R. chalepensis and relevant in silico studies on the most active compounds.


Assuntos
Simulação por Computador , Furocumarinas/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Ruta/química , Ruta/crescimento & desenvolvimento , Rutina/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Furocumarinas/química , Furocumarinas/isolamento & purificação , Ligação de Hidrogênio , Iraque , Ligantes , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Rutina/química , Rutina/isolamento & purificação
4.
Artigo em Inglês | MEDLINE | ID: mdl-33656137

RESUMO

Nasal carriage of Staphylococcus aureus by healthcare workers is of great clinical importance as it facilitates the contamination of medical devices and cross-transmission. However, studies regarding the epidemiology and dissemination of S. aureus and Methicillin-resistant S. aureus (MRSA) within the Primary Health Care in Brazil are scarce. The current study aimed to detect and characterize S. aureus and MRSA strains from the nasal cavities of 63 healthcare working in primary health care units in order to determine the prevalence of S. aureus and MRSA, biofilm formation and resistance profile of these isolates. PCR reactions were performed for detecting mecA, icaA and icaD genes. The phenotypic antimicrobial susceptibility was assessed by the disk diffusion method and biofilm formation by the Congo Red Agar (CRA) method. The MRSA isolates were typed for the Staphylococcal Cassette Chromosome mec (SCCmec). The prevalence of nasal carriage of S. aureus was 74.6%, of which 72.3% were MRSA carrying SCCmec type I (24.4%), III (34.1%), IV (36.6%). Two (4.9%) isolates presented a non-typeable cassette by the performed technique. The antimicrobial susceptibility evaluation evidenced penicillin resistance in 66.1% of S. aureus, erythromycin resistance in 49.2%, while 37.3% were resistant to oxacillin, 28.8% to cefoxitin, 5.1% to levofloxacin and 5.1% to clindamycin. All isolates were biofilm producers and 96.6% of the strains contained the ica biofilm-forming genes (icaA and/or icaD). We have demonstrated a high prevalence of S. aureus and MRSA carriage among health care working in Primary Health Care units, the presence of SCCmec types I, III and IV, in addition to their high ability to form biofilm, factors that possibly contribute to the dissemination and persistence of these pathogens within the primary care services. These observations highlight the importance of broadening the perspective of Health Care-Associated Infections prevention, including all health care levels, which are currently little explored. In addition, the dynamics and resistance mechanisms of S. aureus transmission still need to be further clarified to enable the implementation of more effective prevention measures.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/microbiologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Nariz/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/genética , Adulto , Biofilmes , Brasil/epidemiologia , Portador Sadio/epidemiologia , Infecção Hospitalar , Estudos Transversais , Feminino , Genes Bacterianos , Pessoal de Saúde , Humanos , Transmissão de Doença Infecciosa do Paciente para o Profissional , Transmissão de Doença Infecciosa do Profissional para o Paciente , Masculino , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , Atenção Primária à Saúde , Estudos Prospectivos , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia
5.
Nat Commun ; 12(1): 1171, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33608525

RESUMO

Direct cloning represents the most efficient strategy to access the vast number of uncharacterized natural product biosynthetic gene clusters (BGCs) for the discovery of novel bioactive compounds. However, due to their large size, repetitive nature, or high GC-content, large-scale cloning of these BGCs remains an overwhelming challenge. Here, we report a scalable direct cloning method named Cas12a-assisted precise targeted cloning using in vivo Cre-lox recombination (CAPTURE) which consists of Cas12a digestion, a DNA assembly approach termed T4 polymerase exo + fill-in DNA assembly, and Cre-lox in vivo DNA circularization. We apply this method to clone 47 BGCs ranging from 10 to 113 kb from both Actinomycetes and Bacilli with ~100% efficiency. Heterologous expression of cloned BGCs leads to the discovery of 15 previously uncharacterized natural products including six cyclic head-to-tail heterodimers with a unique 5/6/6/6/5 pentacyclic carbon skeleton, designated as bipentaromycins A-F. Four of the bipentaromycins show strong antimicrobial activity to both Gram-positive and Gram-negative bacteria such as methicillin-resistant Staphylococcus aureus, vancomycinresistant Enterococcus faecium, and bioweapon Bacillus anthracis. Due to its robustness and efficiency, our direct cloning method coupled with heterologous expression provides an effective strategy for large-scale discovery of novel natural products.


Assuntos
Proteínas de Bactérias/genética , Proteínas Associadas a CRISPR/genética , Clonagem Molecular/métodos , Endodesoxirribonucleases/genética , Integrases/genética , Recombinação Genética , Actinobacteria/genética , Actinobacteria/metabolismo , Produtos Biológicos/metabolismo , Vias Biossintéticas/genética , DNA Bacteriano , Enterococcus faecium/genética , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/metabolismo , Bactérias Gram-Positivas/genética , Bactérias Gram-Positivas/metabolismo , Staphylococcus aureus Resistente à Meticilina/genética , Família Multigênica , Streptomyces/genética
6.
BMC Infect Dis ; 21(1): 153, 2021 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-33549035

RESUMO

BACKGROUND: This systematic review and meta-analysis explored the relationship between vancomycin (VCM) monitoring strategies and VCM effectiveness and safety. METHODS: We conducted our analysis using the MEDLINE, Web of Sciences, and Cochrane Register of Controlled Trials electronic databases searched on August 9, 2020. We calculated odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Adult patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia with VCM trough concentrations ≥15 µg/mL had significantly lower treatment failure rates (OR 0.63, 95% CI 0.47-0.85). The incidence of acute kidney injury (AKI) increased with increased trough concentrations and was significantly higher for trough concentrations ≥20 µg/mL compared to those at 15-20 µg/mL (OR 2.39, 95% CI 1.78-3.20). Analysis of the target area under the curve/minimum inhibitory concentration ratios (AUC/MIC) showed significantly lower treatment failure rates for high AUC/MIC (cut-off 400 ± 15%) (OR 0.28, 95% CI 0.18-0.45). The safety analysis revealed that high AUC value (cut-off 600 ± 15%) significantly increased the risk of AKI (OR 2.10, 95% CI 1.13-3.89). Our meta-analysis of differences in monitoring strategies included four studies. The incidence of AKI tended to be lower in AUC-guided monitoring than in trough-guided monitoring (OR 0.54, 95% CI 0.28-1.01); however, it was not significant in the analysis of mortality. CONCLUSIONS: We identified VCM trough concentrations and AUC values that correlated with effectiveness and safety. Furthermore, compared to trough-guided monitoring, AUC-guided monitoring showed potential for decreasing nephrotoxicity.


Assuntos
Antibacterianos/uso terapêutico , Monitoramento de Medicamentos/métodos , Vancomicina/uso terapêutico , Lesão Renal Aguda/induzido quimicamente , Lesão Renal Aguda/epidemiologia , Adulto , Antibacterianos/farmacologia , Área Sob a Curva , Bacteriemia/tratamento farmacológico , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Razão de Chances , Segurança , Infecções Estafilocócicas/tratamento farmacológico , Falha de Tratamento , Vancomicina/farmacologia
7.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(1): 272-277, 2021 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-33554833

RESUMO

OBJECTIVE: To analyze the distribution and drug resistance of pathogens sampled from the patients with bloodstream infection in the department of hematology of PLA General Hospital, so as to provide evidences for clinical prevention and control infection. METHODS: From January 2014 to December 2017, A total of 286 cases-time positive blood culture samples from 212 patients in the department of hematology of the General Hospital of Chinese PLA were collected. The clinical characteristics of patients and the distribution and drug resistance of pathogens were analyzed retrospectively. RESULTS: 182(63.64%) bacterial strains were Gram-negative, and the other 104(36.36%) were Gram-positive. There were 88 strains of Escherichia coli(30.77%), 34 strains of Pseudomonas aeruginosa(11.89%), 26 strains of Klebsiella pneumoniae(9.09%), 25 strains of Staphylococcus epidermidis(8.74%), 20 strains of Gram-positive rods(6.99%), 16 strains of Staphylococcus hominis(5.59%), 11 strains of Etaphylococcus haemolyticus(3.85%), 10 strains of Staphylococcus aureus(3.50%), 6 strains of Staphylococcus capitis(2.10%), 5 strains of Acinetobacter baumannii(1.75%) and so on. Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae as Gram-negative bacteria were sensitive to amikacin. Staphylococcus epidermidis and Staphylococcus aureus as Gram-positive bacteria were sensitive to vancomycin and nitrofurantoin. CONCLUSION: The blood culture patients with bloodstream infection in department of hematology of our hospital confirmed that more infections are Gram-negative. The clinicians should choose suitable antibiotics according to the results of bacterial culture and drug sensitive test.


Assuntos
Doenças Hematológicas , Staphylococcus aureus Resistente à Meticilina , Sepse , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Estudos Retrospectivos
8.
J Assoc Physicians India ; 69(2): 73-74, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33527820

RESUMO

Pseudo-aneurysm of the brachial artery is relatively rare condition affecting the arterial vessels of the limbs. It can be due to trauma, infections or systemic vasculitis. We report a patient with aplastic anemia who developed pseudoaneurysm of the brachial artery following an episode of bacterial sepsis. Methicillin resistant Staphylococcus aureus (MRSA) was isolated on blood culture. Patient was treated with systemic antibiotics and underwent embolization of the pseudo-aneurysm. He later developed vascular insufficiency of the forearm and a stent had to be placed in the brachial artery at the site of calcified thrombus inside the pseudo-aneurysm to produce the patency of the artery and ensure adequate blood flow to forearm and hand.


Assuntos
Anemia Aplástica , Falso Aneurisma , Aneurisma Infectado , Staphylococcus aureus Resistente à Meticilina , Anemia Aplástica/complicações , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/etiologia , Falso Aneurisma/terapia , Aneurisma Infectado/diagnóstico por imagem , Aneurisma Infectado/terapia , Artéria Braquial/diagnóstico por imagem , Humanos , Masculino
9.
Klin Lab Diagn ; 66(1): 42-44, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33567172

RESUMO

1235 strains of Staphylococci isolated in a multidisciplinary children's clinic were analyzed. The species and antibiotic resistance of Golden and coagulase-negative Staphylococci were studied. The most frequently identified species were: S. aureus-36.06%, S. epidermidis-23.05%, S. haemolyticus-19.7%, S. hominis-14.03%. Phenotype methicillinsensitive strains had 48.9% of the allocated staphylococci, while metitillinrezistentnykh S. aureus was identified in 25.6%, and coagulase-negative staphylococci methicillinresistant- 63.2 per cent. The frequency of associated resistance to aminoglycosides, fluoroquinolones, macrolides and tetracyclines have metitillinresictant strains 92,7%, 78,3%, 83,4% and 52,05% respectively, resistant Staphylococcus and coagulase-negative staphylococci were similar. The minimum number of resistant strains was found in relation to daptomycin, no strains resistant to vancomycin and linezolid were found. Antibiotic resistance of staphylococci in children's hospitals is determined by the presence of the mecA gene or sensitivity to cefoxitin and does not depend on the type of strain.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Criança , Coagulase/genética , Resistência Microbiana a Medicamentos , Hospitais , Humanos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Staphylococcus/genética , Staphylococcus aureus
10.
BMJ Case Rep ; 14(2)2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33563686

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) can cause a wide range of skin infections, however MRSA panniculitis without bacteremia is a rare manifestation. Here, we report a woman in her 20s with relapsed Hodgkin lymphoma undergoing stem cell mobilisation who presented with bilateral subcutaneous nodules over her shins. Ultrasound scan of one nodule showed non-specific inflammatory changes. Punch biopsy of a nodule showed lobular panniculitis with Gram-positive cocci. Blood cultures were negative but a culture from the biopsy grew MRSA. She was started on doxycycline with improvement in her symptoms. This case serves as a reminder to consider infections as a cause of panniculitis in immunocompromised patients.


Assuntos
Mobilização de Células-Tronco Hematopoéticas , Paniculite/microbiologia , Infecções Estafilocócicas/microbiologia , Adulto , Antibacterianos/uso terapêutico , Biópsia , Doxiciclina/uso terapêutico , Feminino , Doença de Hodgkin/terapia , Humanos , Hospedeiro Imunocomprometido , Staphylococcus aureus Resistente à Meticilina , Paniculite/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológico
11.
Niger J Clin Pract ; 24(2): 225-232, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33605913

RESUMO

Background: Infections with Staphylococcus aureus cause significant morbidity and mortality worldwide. Resistant strains of S. aureus to commonly used antibiotics are being increasingly encountered in clinical practice, necessitating the need to determine the resistance pattern in Nigeria. Methods: Antibiotic susceptibility testing was performed on 360 S. aureus isolates from clinical specimen from seven hospitals across the six geo-political regions of Nigeria using Kirby Bauer disc diffusion technique, and E-test for vancomycin. Cefoxitin 30 µg disc was used to determine methicillin resistance, and D-test for inducible clindamycin resistance. Results: Methicillin-resistant S. aureus was confirmed in 176 (48.9%) of the isolates, 346 (96%) for penicillin G and 311 (86.4%) for trimethoprim. 175 (99.4%) of the 176 resistant to methicillin were susceptible to vancomycin. Linezolid, tigecycline, chloramphenicol and clindamycin had susceptibilities of 341 (94.7%), 332 (92.2%), 298 (82.8%) and 290 (80.6%) respectively. Inducible clindamycin resistance was elucidated in 25 (29.1%) of the 86 isolates. Generally, MRSA isolates were more resistant than methicillin-sensitive S. aureus (MSSA) to all antibiotics tested. Conclusion: Staphylococcus aureus rates of resistance are high and call for urgent action such as antibiotic stewardship programmes and periodic surveillance to enhance clinical outcomes. While targeted therapy is preferred, options for empiric treatment include chloramphenicol, clindamycin, linezolid or vancomycin.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Hospitais , Humanos , Testes de Sensibilidade Microbiana , Nigéria
12.
BMJ Case Rep ; 14(2)2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568405

RESUMO

Diagnosis of source of maxillofacial infection in paediatric patients can be challenging due to difficulty in eliciting a proper history and multiple potential sources of infection. Identification and removal of the nidus of infection with decompression and institution of antibiotic therapy as per the culture-sensitivity report form the mainstay treatment of the infection. Deviation from it may result in persistence or even progression of infection, resulting in significant morbidity and mortality. In the past decade, the incidence of community-acquired methicillin-resistant Staphylococcus aureus infection in the oral cavity has seen an upward trend. This has further led to an increase in complexity in the diagnosis of maxillofacial infections. In this case, the authors want to bring to light the challenges faced in managing a paediatric patient with persistent fascial space infection even after removal of the offending tooth, which signifies the importance of managing the infection by the time-tested protocol.


Assuntos
Antibacterianos/uso terapêutico , Clindamicina/uso terapêutico , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/cirurgia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/cirurgia , Periodontite Agressiva/complicações , Periodontite Agressiva/fisiopatologia , Criança , Cárie Dentária/complicações , Cárie Dentária/fisiopatologia , Feminino , Humanos , Resultado do Tratamento
13.
Arch. argent. pediatr ; 119(1): 11-17, feb. 2021. tab, ilus
Artigo em Inglês, Espanhol | LILACS, BINACIS | ID: biblio-1147054

RESUMO

Introducción. Las infecciones por Staphylococcus aureus resistente a meticilina adquirido de la comunidad (SARM-AC) se han incrementado en los últimos años. Neumonías necrotizantes y empiemas por SARM-AC son cada vez más frecuentes en niños.Objetivos. Determinar la prevalencia de neumonías por SARM-AC y sus características clínico-epidemiológicas, en comparación con las neumonías por Streptococcus pneumoniae (SP) en la misma población.Material y métodos. Estudio descriptivo, observacional, transversal, de pacientes internados con neumonía por SARM-AC en el Hospital de Niños Víctor J. Vilela (período: 1/2008-12/2017).Resultados. De 54 neumonías por Staphylococcus aureus, 46 (el 85 %) fueron SARM-AC. El índice de neumonías por SARM-AC varió de 4,9/10 000 (2008) a 10/10 000 egresos (2017). Presentaron sepsis/shock séptico el 41 %; empiema, el 96 %; neumotórax, el 35 %; requirieron drenaje pleural el 90 % y toilette quirúrgica el 55 %. Ingresaron a Terapia Intensiva el 65 %; la mitad necesitó asistencia respiratoria mecánica. Hubo dos muertes. Resistencia de las cepas: el 17 % a gentamicina, el 13 % a eritromicina, el 11 % a clindamicina. En las neumonías por SARM-AC vs. las neumonías por SP, se observó mayor riesgo de sepsis (IC 95 %; RR 7,38; 3,32-16,38) e ingreso a Terapia Intensiva (RR 4,29; 2,70-6,83). No hubo muertes por SP.Conclusiones. La prevalencia de neumonías por SARM-AC se duplicó durante la última década. Comparadas con las neumonías por SP, las neumonías por SARM-AC se acompañaron, más frecuentemente, de cuadros de sepsis y shockséptico, ingreso a Terapia Intensiva y asistencia respiratoria.


Introduction. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have increased in recent years. CA-MRSA necrotizing pneumonia and empyema are now more common in children.Objectives. To determine the prevalence of CA-MRSA pneumonia and its clinical and epidemiological characteristics compared to Streptococcus pneumoniae (SP) pneumonia in the same population.Material and methods. Descriptive, observational, cross-sectional study of patients hospitalized due to CA-MRSA pneumonia at Hospital de Niños Víctor J. Vilela (period: January 2008-December 2017).Results. Out of 54 Staphylococcus aureus pneumonia cases, 46 (85 %) corresponded to CA-MRSA. The rate of CA-MRSA pneumonia ranged from 4.9/10 000 (2008) to 10/10 000 hospital discharges (2017). Sepsis/septic shock was observed in 41 %; empyema, in 96 %; pneumothorax, in 35 %; 90 % of cases required pleural drainage and 55 %, surgical debridement. Also, 65 % of patients were admitted to the intensive care unit (ICU); half of them required assisted mechanical ventilation. Two patients died. Strain resistance: 17 %, gentamicin; 13 %, erythromycin; and 11 %, clindamycin. Compared to SP pneumonia, CA-MRSA pneumonia showed a higher risk for sepsis (95 % confidence interval; relative risk: 7.38; 3.32-16.38) and admission to the ICU (RR: 4.29; 2.70-6.83). No patient died due to SP pneumonia.Conclusions. The prevalence of CA-MRSA pneumonia doubled in the past decade. Compared to SP pneumonia, CA-MRSA pneumonia was more commonly accompanied by sepsis and septic shock, admission to the ICU, and ventilatory support requirement


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Infecções Estafilocócicas/epidemiologia , Infecções Comunitárias Adquiridas/epidemiologia , Staphylococcus aureus Resistente à Meticilina , Argentina/epidemiologia , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Testes de Sensibilidade Microbiana , Epidemiologia Descritiva , Incidência , Prevalência , Estudos Transversais , Infecções Comunitárias Adquiridas/diagnóstico , Infecções Comunitárias Adquiridas/microbiologia , Hospitais Pediátricos
14.
ACS Appl Mater Interfaces ; 13(7): 8082-8094, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33570927

RESUMO

Antibiotic-resistant bacteria are a significant and growing threat to human health. Recently, two-dimensional (2D) nanomaterials have shown antimicrobial activity and have the potential to be used as new approaches to treating antibiotic resistant bacteria. In this Research Article, we exfoliate transition metal dichalcogenide (TMDC) nanosheets using synthetic single-stranded DNA (ssDNA) sequences, and demonstrate the broad-spectrum antibacterial activity of MoSe2 encapsulated by the T20 ssDNA sequence in eliminating several multidrug-resistant (MDR) bacteria. The MoSe2/T20 is able to eradicate Gram-positive Escherichia coli and Gram-positive Staphylococcus aureus at much lower concentrations than graphene-based nanomaterials. Eradication of MDR strains of methicillin-resistant S. aureus (MRSA), Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii are shown to occur at at 75 µg mL-1 concentration of MoSe2/T20, and E. coli at 150 µg mL-1. Molecular dynamics simulations show that the thymine bases in the T20 sequence lie flat on the MoSe2 surface and can, thus, form a very good conformal coating and allow the MoSe2 to act as a sharp nanoknife. Electron microscopy shows the MoSe2 nanosheets cutting through the cell membranes, resulting in significant cellular damage and the formation of interior voids. Further assays show the change in membrane potential and reactive oxygen species (ROS) formation as mechanisms of antimicrobial activity of MoSe2/T20. The cellular death pathways are also examined by mRNA expression. This work shows that biocompatible TMDCs, specifically MoSe2/T20, is a potent antimicrobial agent against MDR bacteria and has potential for clinical settings.


Assuntos
Antibacterianos/farmacologia , Calcogênios/farmacologia , DNA de Cadeia Simples/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Metais Pesados/farmacologia , Células A549 , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/química , Cápsulas/química , Cápsulas/farmacologia , Calcogênios/química , DNA de Cadeia Simples/síntese química , Enterococcus faecalis/efeitos dos fármacos , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Metais Pesados/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Pseudomonas aeruginosa/efeitos dos fármacos , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Propriedades de Superfície
15.
Am J Vet Res ; 82(3): 189-197, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33629894

RESUMO

OBJECTIVE: To compare the effect of multiple wound dressings on microbial growth in a perfused equine wound model. SAMPLE: Abdominal musculocutaneous flaps from 16 equine cadavers. PROCEDURES: 8 full-thickness skin wound covered were created in each flap. Tissues were perfused with saline (0.9% NaCl) solution. Wounds were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa (106 CFUs), incubated, and covered with a dressing containing activated charcoal, boric acid, cadexomer iodine, calcium alginate, manuka honey, nanoparticle silver, or polyhexamethylene biguanide or with a control (nonadherent gauze) dressing. Muscle biopsy specimens were obtained at baseline (immediately prior to dressing application) and 6, 12, 18, and 24 hours later for mean bacterial load (MBL) determination. The MBLs at each subsequent time point were compared with that at baseline within dressing types, and MBLs at each time point were compared among dressing types. RESULTS: MBLs in MRSA-inoculated wounds covered with cadexomer iodine dressings were significantly decreased from baseline at the 6- and 12-hour time points. For P aeruginosa-inoculated wounds, MBLs were significantly increased from baseline in all wounds at various times except for wounds with cadexomer iodine dressings. The MBLs of wounds with cadexomer iodine dressings were lower than all others, although not always significantly different from those for wounds with boric acid, manuka honey, nanoparticle silver, and polyhexamethylene biguanide dressings. CONCLUSIONS AND CLINICAL RELEVANCE: In this nonviable perfused wound model, growth of MRSA and P aeruginosa was most effectively reduced or inhibited by cadexomer iodine dressings. These results and the effect of the dressings on wound healing should be confirmed with in vivo studies.


Assuntos
Doenças dos Cavalos , Staphylococcus aureus Resistente à Meticilina , Retalho Miocutâneo , Infecção dos Ferimentos , Animais , Bandagens , Cavalos , Pseudomonas aeruginosa , Cicatrização , Infecção dos Ferimentos/veterinária
16.
Braz J Infect Dis ; 25(1): 101539, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33607082

RESUMO

BACKGROUND: Community-genotype methicillin-resistant Staphylococcus aureus (CG-MRSA) emerged in the 1990s as a global community pathogen primarily involved in skin and soft tissue infections (SSTIs) and pneumonia. To date, the CG-MRSA SSTI burden in Latin America (LA) has not been assessed. OBJECTIVE: The main objective of this study was to report the rate and genotypes of community-genotype methicillin-resistant Staphylococcus aureus (CG-MRSA) causing community-onset skin and soft tissue infections (CO-SSTIs) in LA over the last two decades. In addition, this research determined relevant data related to SSTIs due to CG-MRSA, including risk factors, other invasive diseases, and mortality. DATA SOURCES: Relevant literature was searched and extracted from five major databases: Embase, PubMed, LILACS, SciELO, and Web of Science. METHODS: A systematic review was performed, and a narrative review was constructed. RESULTS: An analysis of 11 studies identified epidemiological data across LA, with Argentina presenting the highest percentage of SSTIs caused by CG-MRSA (88%). Other countries had rates of CG-MRSA infection ranging from 0 to 51%. Brazil had one of the lowest rates of CG-MRSA SSTI (4.5-25%). In Argentina, being younger than 50 years of age and having purulent lesions were predictive factors for CG-MRSA CO-SSTIs. In addition, the predominant genetic lineages in LA belonged to sequence types 8, 30, and 5 (ST8, ST30, and ST5). CONCLUSION: There are significant regional differences in the rates of CG-MRSA causing CO-SSTIs. It is not possible to conclude whether or not CG-MRSA CO-SSTIs resulted in more severe SSTI presentations or in a higher mortality rate.


Assuntos
Infecções Comunitárias Adquiridas , Staphylococcus aureus Resistente à Meticilina , Infecções dos Tecidos Moles , Infecções Estafilocócicas , Infecções Cutâneas Estafilocócicas , Antibacterianos/uso terapêutico , Argentina , Brasil , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/epidemiologia , Genótipo , Humanos , América Latina/epidemiologia , Staphylococcus aureus Resistente à Meticilina/genética , Infecções dos Tecidos Moles/tratamento farmacológico , Infecções dos Tecidos Moles/epidemiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Infecções Cutâneas Estafilocócicas/epidemiologia
17.
BMC Infect Dis ; 21(1): 177, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33588782

RESUMO

BACKGROUND: Positive blood cultures showing Gram positive cocci in clusters signifies either Staphylococcus aureus or the less-virulent coagulase-negative staphylococci. Rapid identification and methicillin susceptibility determination with the Xpert MRSA/SA BC assay can improve management of S. aureus bloodstream infection and reduce inappropriate antibiotic use. METHODS: We prospectively evaluated the Xpert MRSA/SA BC assay in comparison with culture, on samples referred to our laboratory in the Western Cape, South Africa. We interviewed attending clinicians upon culture result availability, to assess antibiotic choices and estimate potential impact of the assay. RESULTS: Of the 231 samples included, there was 100% concordance between the Xpert MRSA/SA BC assay and culture (methicillin-resistant S. aureus 15/15, methicillin-susceptible S. aureus 42/42, coagulase-negative staphylococci 170/170). Time to final result could be reduced by approximately 30 h with the assay. Of the 178 patients with adequate antibiotic history, optimisation of antistaphylococcal therapy could have occurred more than 1 day sooner in 68.9% with S. aureus bloodstream infection (31/45, 95% CI 53.2-81.4%). Six of the 11 patients with methicillin-resistant S. aureus bloodstream infection (54.5%) could have received anti-MRSA cover sooner. Fifty-four days of antibiotic therapy could have been spared, equating to 0.3 days (95% CI, 0.2-0.4) saved per patient, driven by broad-spectrum beta-lactams (32 days, in 18.0% of the cohort). CONCLUSION: This assay has potential as an antimicrobial stewardship tool; costing and impact on clinical outcome in patients with S. aureus bloodstream infection should be assessed.


Assuntos
Antibacterianos/uso terapêutico , Gestão de Antimicrobianos/métodos , Meticilina/uso terapêutico , Técnicas de Diagnóstico Molecular/métodos , Infecções Estafilocócicas/tratamento farmacológico , Adulto , Antibacterianos/farmacologia , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Pessoa de Meia-Idade , Estudos Prospectivos , África do Sul , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Staphylococcus/genética , Staphylococcus/isolamento & purificação , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Fatores de Tempo
18.
Orv Hetil ; 162(3): 106-111, 2021 01 17.
Artigo em Húngaro | MEDLINE | ID: mdl-33459605

RESUMO

Összefoglaló. Bevezetés: A multirezisztens kórokozók által okozott fertozések komoly gondot okoznak. Szemészeti szempontból az ebbe a körbe tartozó meticillinrezisztens Staphylococcus aureus (MRSA) baktérium bír kiemelkedo jelentoséggel. Célkituzés: Multirezisztens kórokozók irányában cataractamutét elott álló betegektol mintavétel és adatelemzés. Módszer: 257, cataractamutét elott álló beteg esetében végeztünk multirezisztens kórokozók szurésére vizsgálatot a conjunctivazsákból. A mikrobiológiai tenyésztés során multirezisztens kórokozóra pozitív eredményt adó betegek esetében a preoperatív kórtörténetet és az általános kíséro betegségeket feltártuk és elemeztük. Eredmények: A minták 17 beteg esetében multirezisztens kórokozóra pozitívak voltak. 11 esetben szisztémás rizikófaktorokat is találtunk. A pozitív betegeknél a mutétet csak a felszabadító mikrobiológiai eredmények birtokában végeztük el. A dekolonizált betegeknél ezt követoen a szakmai protokoll normális antibiotikumprevencióját alkalmaztuk. A 257 beteg 6,6%-ában találtunk multirezisztenskórokozó- és 5%-ában MRSA-pozitivitást. Posztoperatív endophthalmitis nem fordult elo. Következtetés: A cataractamutéteknél alkalmazott antibiotikus endophthalmitisprevenció multirezisztens kórokozóra pozitív betegeknél kevéssé hatékony lehet. Ezért javasolt a veszélyeztetett betegek multirezisztens kórokozókra történo szurése és dekolonizációja. Orv Hetil. 2021; 162(3): 106-111. INTRODUCTION: Infections caused by multiresistant pathogens may have serious consequences. In ophthalmological practice, methicillin-resistant Staphylococcus aureus (MRSA) is the most important multiresistant pathogen. OBJECTIVE: We took samples for multiresistant pathogens from patients assigned for cataract surgery. METHOD: We carried out multiresistant pathogen screening from conjunctival sac in 257 patients, who were assigned for cataract surgery. Preoperative case history and concomitant systemic diseases were evaluated in patients, who turned out to be positive for multiresistant pathogens during the screening procedure. RESULTS: The samples were positive for multiresistant pathogens in 17 patients. In the case history of 11 multiresistant pathogen positive patients, previous systemic risk factors could be explored. Multiresistant pathogen positive patients were operated only after the decolonisation. After the decolonisation, the normal antibiotic prevention was used before the surgery. Multiresistant pathogen positive was 6.6%, MRSA positive was 5% of the 257 patients. There were no cases of endophthalmitis in any of these patients. CONCLUSION: Endophthalmitis prevention with antibiotics, according to the guidelines, may not be efficient in multiresistant pathogen positive patients. Therefore, it is advisable to screen multiresistant pathogens and decolonisation at risk patients before cataract surgery. Orv Hetil. 2021; 162(3): 106-111.


Assuntos
Catarata/microbiologia , Endoftalmite/prevenção & controle , Aparelho Lacrimal/microbiologia , Staphylococcus aureus Resistente à Meticilina , Extração de Catarata , Humanos , Programas de Rastreamento , Estudos Retrospectivos
19.
Drug Dev Ind Pharm ; 47(2): 280-291, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33493022

RESUMO

Osteomyelitis is one of the infections of the bone, and the treatment needs to the infection problems. Here, a local therapeutic approach for efficient drug delivery systems was designed to enhance the antibiotic drug's therapeutic activity. Calcium-Alginate nanoparticle (Ca-Alg) crosslinked phosphorylated polyallylamine (PPAA) was prepared through the salting-out technique, and it achieved 82.55% encapsulation of Clindamycin drug. The physicochemical characterizations of FTIR, SEM/EDX, TEM, and XRD were investigated to confirm the materials nature and formation. Clindamycin loaded Ca-Alg/PPAA system showed sustained Clindamycin release from the carrier. Cell viability was assessed in bone-related cells by Trypan blue assay and MTT assay analysis method. Both assay results exhibited better cell viability of synthesized materials against MG63 cells. MIC value of Ca-Alg/PPAA/Clindamycin in the Methicillin-resistant Staphylococcus aureus (MRSA) pathogen was 275 µg/mL, and it was 120 µg/mL for Enterobacter cloacae pathogen. The materials promising material for Osteomyelitis affected bone regeneration without any destructive effect and speedy recovery of infected parts from these investigations.


Assuntos
Clindamicina/química , Staphylococcus aureus Resistente à Meticilina , Nanopartículas , Osteomielite , Poliaminas/química , Infecções Estafilocócicas , Staphylococcus aureus/química , Alginatos/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Clindamicina/administração & dosagem , Preparações de Ação Retardada/uso terapêutico , Humanos , Osteomielite/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológico
20.
Appl Environ Microbiol ; 87(6)2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33397701

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) presenting spa type t899 is commonly associated with sequence type 9 (ST9) but is also increasingly linked to ST398. This study provides genomic insight into the diversity of t899 isolates using core genome multilocus sequence typing (cgMLST), single nucleotide polymorphism (SNP)-based phylogeny, and the description of selected antimicrobial resistance and virulence markers. The SNP-based phylogenic tree showed that isolates sharing the same spa type (t899) but different STs highly diverged in their core and accessory genomes, revealing discriminant antimicrobial resistance (AMR) and virulence markers. Our results highlighted the idea that in a surveillance context where only spa typing is used, an additional multiplex PCR for the detection of the tet(M), sak, and seg genes would be valuable in helping distinguish ST9 from ST398 isolates on a routine basis.IMPORTANCE This study showed the genetic diversity and population structure of S. aureus presenting the same spa type, t899, but belonging to different STs. Our findings revealed that these isolates vary deeply in their core and accessory genomes, contrary to what is regularly inferred from studies using spa typing only. Given that identical spa types can be associated with different STs and that spa typing only is not appropriate for S. aureus isolates that have undergone major recombination events which include the passage of the spa gene (such as in t899-positive MRSA), the combination of both MLST and spa typing methods is recommended. However, spa typing alone is still largely used in surveillance studies and basic characterization. Our data suggest that additional markers, such as tet(M), sak, and seg genes, could be implemented in an easy and inexpensive manner in order to identify S. aureus lineages with a higher accuracy.


Assuntos
Staphylococcus aureus Resistente à Meticilina/genética , Farmacorresistência Bacteriana/genética , Genes Bacterianos , Genoma Bacteriano , Genômica , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Tipagem de Sequências Multilocus , Filogenia , Polimorfismo de Nucleotídeo Único , Fatores de Virulência/genética
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