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1.
J Med Microbiol ; 70(8)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34338626

RESUMO

Introduction. Biofilm formation is a major virulence factor associated with Staphylococcus aureus infections. However, the influence of plasma proteins on biofilm formation of clinical isolates in vitro remains unclear.Hypotheses. We hypothesized that coating surfaces with plasma proteins might induce biofilm formation by S. aureus of different clonal lineages.Aim. To evaluate biofilm production by clinical S. aureus isolates of different clonal lineages isolated in Rio de Janeiro hospitals and investigated the presence of biofilm-associated genes.Methodology. This study assessed biofilm production of 60 S. aureus isolates in polystyrene microtitre plates with and without fibrinogen or fibronectin. The biochemical composition of the biofilm matrices was determined and the biofilm formation on fibrinogen-coated surfaces was also evaluated by confocal laser scanning microscopy. The presence of biofilm-related genes was detected by PCR, and the typing and functionality of agr operon was also evaluated.Results. Most of the isolates (45 %) were weak biofilm producers or non-producers. However, most of them presented a significant increase in biofilm production on plates covered with plasma proteins. There was no significant difference in biofilm formation between methicillin-resistant and -susceptible S. aureus isolates, or between different clonal lineages, except for ST30-IV (weak producers) and ST239-III (strong producers). The fnbB gene was associated with higher biofilm production.Conclusion. An increase in biofilm production in the presence of plasma proteins highlights the importance of investigating biofilm formation by S. aureus clinical isolates under different conditions since this virulence factor contributes to persistent infections and increased resistance to antimicrobials.


Assuntos
Biofilmes/crescimento & desenvolvimento , Fibrinogênio , Fibronectinas , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Staphylococcus aureus/patogenicidade , Adesinas Bacterianas/genética , Aderência Bacteriana/genética , Proteínas de Bactérias/genética , Genes Bacterianos , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/fisiologia , Óperon , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/fisiologia , Transativadores/genética
2.
Expert Opin Drug Metab Toxicol ; 17(9): 1039-1048, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34225556

RESUMO

Introduction: Usage of ceftriaxone-based therapy to treat Methicillin-Susceptible Staphylococcus aureus (MSSA) infections is a controversial issue, from in vitro to clinical studies.Area covered: We conducted a literature review using PubMed of articles with ceftriaxone pharmacokinetics parameters and built a probability of target attainment (PTA) based on PK values from stable conditions (non-critically-ill patients) with goals of fT>55%, fT>75%, and fT>100%. Ceftriaxone's minimal inhibitory concentration from 31 MSSA strains (0.25-64 mg/L) was used to build the cumulative fraction response (CFR). The isolates were clinically relevant from blood, bronchoalveolar lavage, and soft tissue biopsy.Expert opinion: The results from controversies about using ceftriaxone for MSSA infections have been commonly addressed in the literature. However, variables such as (i) pharmacokinetic profile, (ii) pharmacodynamic target, (iii) site of infection, and (iv) MIC distributions may influence divergences. From this pharmacokinetics-pharmacodynamics perspective, ceftriaxone may be a reasonable option for MSSA infections when the MIC50 and MIC90 were 4 mg/L and 8 mg/L. CFR analysis demonstrated that ceftriaxone 1 g q24 h could be used if bacteriostasis is the aim (fT>55%), while 1 g q12h should be used for bactericidal effects (fT>75% or fT>100%). These dosing regimens should be considered in other clinical trials.


Assuntos
Antibacterianos/administração & dosagem , Ceftriaxona/administração & dosagem , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Ceftriaxona/farmacocinética , Ceftriaxona/farmacologia , Esquema de Medicação , Farmacorresistência Bacteriana , Humanos , Meticilina/farmacologia , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação
3.
J Med Microbiol ; 70(7)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34269673

RESUMO

Introduction. Staphylococcus aureus is a major cause of hospital infections worldwide. Awareness towards methicillin-resistant S. aureus (MRSA) infections is high but attention towards borderline oxacillin-resistant S. aureus (BORSA) is limited, possibly due to an underestimated clinical relevance, presumption of low incidence and diagnostic limitations.Gap statement. BORSA surveillance has not been routinely implemented, and thus consensus with regard to a definition and infection control measures is lacking.Aim. Our goals were to investigate the occurrence, molecular characteristics and clinical manifestations of BORSA infections in the hospital setting.Methodology. Following an increased incidence in 2016, BORSA cases in 2014/2016 (in our institution) were more specifically evaluated. Medical records were reviewed to investigate epidemiological links, clinical characteristics and outcomes. Resistance and virulence markers were assessed by whole genome sequencing (WGS). Conventional methods: amplified fragment length polymorphism (AFLP) ; multilocus sequence typing (MLST) and multiple locus variable-number tandem repeat analysis (MLVA) were compared with core genome MLST (cgMLST) and whole-genome single nucleotide polymorphism (wgSNP) analysis to confirm genetic clusters.Results. From 2009 to 2013, BORSA comprised 0.1 % of all clinical S. aureus strains. In 2016, the incidence was six-fold higher in comparison to the baseline. Whole-genome SNP and cgMLST confirmed two BORSA clusters among patients with dermatological conditions. Patients with BORSA presented with skin infections, and one case developed a severe invasive infection with a fatal outcome. Infection control measures successfully prevented further transmission in both clusters. WGS findings showed that BORSA strains carried multiple resistance and virulence genes with increased pathogenic potential.Conclusion. WGS and cgMLST effectively characterized and confirmed BORSA clusters among at-risk patients with clinical manifestations ranging from mild skin infections to life-threatening bacteraemia. Clinical awareness and active monitoring are therefore warranted for the timely implementation of infection control measures to prevent BORSA transmission in high-risk patients.


Assuntos
Antibacterianos/farmacologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana , Oxacilina/farmacologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Infecção Hospitalar/transmissão , Genoma Bacteriano , Hospitais/estatística & dados numéricos , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Polimorfismo de Nucleotídeo Único , Infecções Estafilocócicas/transmissão , Staphylococcus aureus/classificação , Staphylococcus aureus/efeitos dos fármacos , Sequenciamento Completo do Genoma
4.
BMC Infect Dis ; 21(1): 627, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210263

RESUMO

BACKGROUND AND OBJECTIVE: Carriage of virulence factors confers some evolutionary benefit to bacteria, which favors the resistant strains. We aimed to analyze whether antibiotic susceptibility of Staphylococcus aureus strains is affected by agr typing, biofilm formation ability, and virulence profiles. METHODS: A total of 123 S. aureus clinical isolates were subjected to antimicrobial susceptibility testing by disk diffusion method, biofilm formation by microtiter plate method, as well as polymerase chain reaction screening to identify virulence genes and the accessory gene regulator (agr) types I-IV. A P value < 0.05 was considered significant. RESULTS: The most prevalent virulence gene was staphyloxanthin crtN, followed by hemolysin genes, capsular cap8H, toxic shock toxin tst, and enterotoxin sea, respectively. Resistant isolates were more commonly found in the agr-negative group than in the agr-positive group. Isolates of agr type III were more virulent than agr I isolates. Strong biofilm producers showed more antibiotic susceptibility and carried more virulence genes than non-strong biofilm producers. Associations were found between the presence of virulence genes and susceptibility to antibiotics. Carriage of the virulence genes and agr was higher in the inpatients; while, resistance and strong biofilms were more prevalent in the outpatients. CONCLUSION: These findings indicated the presence of several virulence factors, biofilm production capacity, agr types and resistance to antibiotics in clinical S. aureus isolates. Considering the importance of S. aureus for human medicine, an understanding of virulence and resistance relationships would help to reduce the impact of S. aureus infections.


Assuntos
Proteínas de Bactérias , Biofilmes , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/fisiologia , Staphylococcus aureus/patogenicidade , Transativadores , Fatores de Virulência/genética , Toxinas Bacterianas/genética , Farmacorresistência Bacteriana , Enterotoxinas/genética , Exfoliatinas/genética , Feminino , Proteínas Hemolisinas/genética , Humanos , Masculino , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , Superantígenos/genética , Xantofilas
5.
Pediatr Infect Dis J ; 40(8): e313-e316, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34250979

RESUMO

Masking and social distancing have been adopted to mitigate the severe acute respiratory syndrome coronavirus 2 pandemic. We evaluated the indirect impact of severe acute respiratory syndrome coronavirus 2 prevention strategies on invasive Staphylococcus aureus, Streptococcus pneumoniae (pneumococcus) and Group A Streptococcus in Houston area children. We observed a decline in invasive pneumococcal disease and invasive Group A Streptococcus temporally associated with social distancing/masking/school closures.


Assuntos
COVID-19/epidemiologia , Infecções Pneumocócicas/epidemiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estreptocócicas/epidemiologia , COVID-19/microbiologia , COVID-19/prevenção & controle , Criança , Coinfecção/epidemiologia , Coinfecção/microbiologia , Coinfecção/virologia , Hospitalização , Humanos , Pandemias , Infecções Pneumocócicas/prevenção & controle , Infecções Pneumocócicas/virologia , Estudos Prospectivos , SARS-CoV-2/isolamento & purificação , Infecções Estafilocócicas/prevenção & controle , Infecções Estafilocócicas/virologia , Staphylococcus aureus/isolamento & purificação , Infecções Estreptocócicas/prevenção & controle , Infecções Estreptocócicas/virologia , Streptococcus pneumoniae/isolamento & purificação , Streptococcus pyogenes/isolamento & purificação
6.
BMC Infect Dis ; 21(1): 701, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34294061

RESUMO

BACKGROUND: Atopic dermatitis (AD) is one of the most frequent chronic and inflammatory skin condition. AD is characterized by damaged epidermal barrier, xerosis and pruritus of eczematous skin lesions which tend to flare. The duration and frequency of exacerbation of AD symptoms markedly affects the quality of patient life. AD results from the interplay between host genetics, immunity, and environmental factors, however the detailed pathogenesis of this disease is still not entirely cleared. Furthermore, disturbances of the skin microbiota and skin functional impairment predispose to secondary skin infections. Staphylococcus aureus colonizes skin and mucous membranes of 20 to 80% of healthy individuals and of 90% of patients with AD in whom this bacterium is accounted as an important AD exacerbating factor. It is also proven, that S. aureus nasal carriage significantly increases the risk for self-transmission and endogenous infection. In the current study the presence of S. aureus either in nasal vestibule and on lesioned skin of 64 patients with AD enrolled in 10-year autovaccination program was determined. The genetic relatedness of 86 S. aureus isolated from patients nose and skin using Pulsed Field Gel Electrophoresis (PFGE) and antimicrobial susceptibility of all strains to methicillin, erythromycin, clindamycin, mupirocin, gentamicin, amikacin, tetracycline, chloramphenicol and cotrimoxazole was also evaluated. RESULTS: In total 23 PFGE genotypes and 24 unique patterns were distinguished. 34 patients were S. aureus nasal carriers. Simultaneous presence of S. aureus in nose and on affected skin was found in 16 carriers colonized by indistinguishable or potentially related S. aureus vs 2 carriers colonized with non-related S. aureus in nasal vestibule and on skin. 4 isolates were methicillin resistant (MRSA) among which 3 showed constitutive MLSB resistance phenotype and remaining one was resistant to tetracycline and chloramphenicol. In 4 isolates inducible MLSB resistance phenotype was found, one of them was additionally resistant to tetracycline. 7 S. aureus were mupirocin resistant among them 3 - isolated from one patient, were resistant simultaneously to tetracyclines and chloramphenicol. 7 strains demonstrated resistance to chloramphenicol and susceptibility to all tested antimicrobial agents. The susceptibility to gentamicin, amikacin and cotrimoxazole among all examined S. aureus was confirmed. CONCLUSION: The obtained results indicated non-clonal structure of S. aureus circulating in AD patients. PFGE results showed the clonal-structure of vast majority of S. aureus isolated from nose and skin from nasal carriers what may prove the autoinfection in these patients. All examined patients the moderate or strong severity of AD was reported. Susceptibility to most antibiotics among isolated strains was also observed.


Assuntos
Antibacterianos/farmacologia , Dermatite Atópica/microbiologia , Cavidade Nasal/microbiologia , Pele/microbiologia , Staphylococcus aureus/genética , Adulto , Dermatite Atópica/terapia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Polônia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação
7.
Theranostics ; 11(14): 6735-6745, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34093850

RESUMO

Background: Nucleic acid (NA)-based diagnostics enable a rapid response to various diseases, but current techniques often require multiple labor-intensive steps, which is a major obstacle to successful translation to a clinical setting. Methods: We report on a surface-engineered single-chamber device for NA extraction and in situ amplification without sample transfer. Our system has two reaction sites: a NA extraction chamber whose surface is patterned with micropillars and a reaction chamber filled with reagents for in situ polymerase-based NA amplification. These two sites are integrated in a single microfluidic device; we applied plastic injection molding for cost-effective, mass-production of the designed device. The micropillars were chemically activated via a nature-inspired silica coating to possess a specific affinity to NA. Results: As a proof-of-concept, a colorimetric pH indicator was coupled to the on-chip analysis of NA for the rapid and convenient detection of pathogens. The NA enrichment efficiency was dependent on the lysate incubation time, as diffusion controls the NA contact with the engineered surface. We could detect down to 1×103 CFU by the naked eye within one hour of the total assay time. Conclusion: We anticipate that the surface engineering technique for NA enrichment could be easily integrated as a part of various types of microfluidic chips for rapid and convenient nucleic acid-based diagnostics.


Assuntos
DNA Bacteriano/análise , Dispositivos Lab-On-A-Chip , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Ácidos Nucleicos/isolamento & purificação , Colorimetria/métodos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Humanos , Microfluídica/métodos , Microscopia Eletrônica de Varredura , Cimento de Policarboxilato/química , Reação em Cadeia da Polimerase em Tempo Real , Dióxido de Silício/química , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Propriedades de Superfície
8.
Anal Methods ; 13(25): 2804-2811, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34075956

RESUMO

The highly effective detection of pathogens in complex biological samples is an attractive and critical topic of study. Bacitracin is a novel broad-spectrum antimicrobial peptide to enrich bacteria via interactions with the membrane surface of the different bacterial cells. In this study, for the first time, bacitracin was immobilized on the surface of Fe3O4@PDA magnetic nanoparticles for the enrichment of Staphylococcus aureus (G+) and Klebsiella pneumoniae (G-). Combined with matrix-assisted laser desorption ionization time-of-flight mass spectrometry, a rapid and sensitive detection method for these two bacteria was developed. In this method, the detectable concentration of bacteria was decreased by 2-3 orders of magnitude in unenriched samples. The enrichment and identification can be completed in one hour. All these results demonstrated that the bacitracin-functionalized magnetic composite has potential for use in the large-scale enrichment and isolation of target pathogens from complex biological samples, opening a new avenue for the rapid and sensitive detection of pathogens.


Assuntos
Klebsiella pneumoniae , Staphylococcus aureus , Bacitracina , Humanos , Klebsiella pneumoniae/isolamento & purificação , Fenômenos Magnéticos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Staphylococcus aureus/isolamento & purificação
9.
J Wound Ostomy Continence Nurs ; 48(4): 292-299, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34186547

RESUMO

PURPOSE: To evaluate the susceptibility profiles of Staphylococcus aureus and Pseudomonas aeruginosa strains identified in chronic venous ulcers treated with platelet-rich plasma (PRP) and petrolatum gauze or petrolatum gauze alone and to quantitatively evaluate the bacterial load and biofilm-forming capacities of the detected S. aureus and P. aeruginosa strains. DESIGN: Randomized controlled trial. SUBJECTS AND SETTING: The convenience sample included 36 participants; 18 were allocated to the PRP combined with the petrolatum gauze group, and 18 were allocated to the control group, which was treated with petrolatum gauze alone. METHODS: Thirty-six patients presenting with chronic venous ulcers were consecutively randomized to the PRP group (n = 18) or the petrolatum gauze control group (n = 18). We followed participants for 3 months during treatment and collected swab cultures from their wounds during weeks 1, 6, and 12 or until the wounds healed. The samples were analyzed using mass spectrometry. Antimicrobial susceptibility tests were performed using disk diffusion. RESULTS: P. aeruginosa was identified in 39 (39%) of 100 samples, and S. aureus was detected in only 10 (10%) samples collected over the study period. At the end of the 12-week treatment period, the wound infections reduced in both the PRP (P = .0078) and control groups (P = .01). The microorganisms were susceptible to most of the tested antimicrobials. The PRP did not increase the bacterial load in the wounds. All S. aureus strains identified showed biofilm-forming capacities and were classified as weak biofilm producers. All P. aeruginosa strains produced biofilm, with 17 strains being classified as weak, 14 as moderate, and 8 as strong biofilm producers. CONCLUSIONS: The PRP plus petrolatum gauze did not increase bacteriological growth or the microbial load in chronic venous ulcers compared with petrolatum gauze alone and could be a considered as an advanced treatment option for these types of chronic wounds.


Assuntos
Plasma Rico em Plaquetas , Pseudomonas aeruginosa/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Úlcera Varicosa/terapia , Infecção dos Ferimentos/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carga Bacteriana , Biofilmes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Infecção dos Ferimentos/microbiologia
10.
BMC Infect Dis ; 21(1): 589, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34154550

RESUMO

BACKGROUND: Bloodstream infections due to Staphylococcus aureus cause significant patient morbidity and mortality worldwide. Of major concern is the emergence and spread of methicillin-resistant S. aureus (MRSA) in bloodstream infections, which are associated with therapeutic failure and increased mortality. METHODS: We generated high quality draft genomes from 323 S. aureus blood culture isolates from patients diagnosed with bloodstream infection at the Dartmouth-Hitchcock Medical Center, New Hampshire, USA in 2010-2018. RESULTS: In silico detection of antimicrobial resistance genes revealed that 133/323 isolates (41.18%) carry horizontally acquired genes conferring resistance to at least three antimicrobial classes, with resistance determinants for aminoglycosides, beta-lactams and macrolides being the most prevalent. The most common resistance genes were blaZ and mecA, which were found in 262/323 (81.11%) and 104/323 (32.20%) isolates, respectively. Majority of the MRSA (102/105 isolates or 97.14%) identified using in vitro screening were related to two clonal complexes (CC) 5 and 8. The two CCs emerged in the New Hampshire population at separate times. We estimated that the time to the most recent common ancestor of CC5 was 1973 (95% highest posterior density (HPD) intervals: 1966-1979) and 1946 for CC8 (95% HPD intervals: 1924-1959). The effective population size of CC8 increased until the late 1960s when it started to level off until late 2000s. The levelling off of CC8 in 1968 coincided with the acquisition of SCCmec Type IV in majority of the strains. The plateau in CC8 also coincided with the acceleration in the population growth of CC5 carrying SCCmec Type II in the early 1970s, which eventually leveled off in the early 1990s. Lastly, we found evidence for frequent recombination in the two clones during their recent clonal expansion, which has likely contributed to their success in the population. CONCLUSIONS: We conclude that the S. aureus population was shaped mainly by the clonal expansion, recombination and co-dominance of two major MRSA clones in the last five decades in New Hampshire, USA. These results have important implications on the development of effective and robust strategies for intervention, control and treatment of life-threatening bloodstream infections.


Assuntos
Staphylococcus aureus Resistente à Meticilina/genética , Sepse/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/genética , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Genômica , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Sepse/tratamento farmacológico , Sepse/virologia , Infecções Estafilocócicas/virologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação
11.
Crit Care ; 25(1): 197, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099016

RESUMO

BACKGROUND: Hospitalized patients with COVID-19 admitted to the intensive care unit (ICU) and requiring mechanical ventilation are at risk of ventilator-associated bacterial infections secondary to SARS-CoV-2 infection. Our study aimed to investigate clinical features of Staphylococcus aureus ventilator-associated pneumonia (SA-VAP) and, if bronchoalveolar lavage samples were available, lung bacterial community features in ICU patients with or without COVID-19. METHODS: We prospectively included hospitalized patients with COVID-19 across two medical ICUs of the Fondazione Policlinico Universitario A. Gemelli IRCCS (Rome, Italy), who developed SA-VAP between 20 March 2020 and 30 October 2020 (thereafter referred to as cases). After 1:2 matching based on the simplified acute physiology score II (SAPS II) and the sequential organ failure assessment (SOFA) score, cases were compared with SA-VAP patients without COVID-19 (controls). Clinical, microbiological, and lung microbiota data were analyzed. RESULTS: We studied two groups of patients (40 COVID-19 and 80 non-COVID-19). COVID-19 patients had a higher rate of late-onset (87.5% versus 63.8%; p = 0.01), methicillin-resistant (65.0% vs 27.5%; p < 0.01) or bacteremic (47.5% vs 6.3%; p < 0.01) infections compared with non-COVID-19 patients. No statistically significant differences between the patient groups were observed in ICU mortality (p = 0.12), clinical cure (p = 0.20) and microbiological eradication (p = 0.31). On multivariable logistic regression analysis, SAPS II and initial inappropriate antimicrobial therapy were independently associated with ICU mortality. Then, lung microbiota characterization in 10 COVID-19 and 16 non-COVID-19 patients revealed that the overall microbial community composition was significantly different between the patient groups (unweighted UniFrac distance, R2 0.15349; p < 0.01). Species diversity was lower in COVID-19 than in non COVID-19 patients (94.4 ± 44.9 vs 152.5 ± 41.8; p < 0.01). Interestingly, we found that S. aureus (log2 fold change, 29.5), Streptococcus anginosus subspecies anginosus (log2 fold change, 24.9), and Olsenella (log2 fold change, 25.7) were significantly enriched in the COVID-19 group compared to the non-COVID-19 group of SA-VAP patients. CONCLUSIONS: In our study population, COVID-19 seemed to significantly affect microbiological and clinical features of SA-VAP as well as to be associated with a peculiar lung microbiota composition.


Assuntos
COVID-19/complicações , Pneumonia Associada à Ventilação Mecânica/microbiologia , Infecções Estafilocócicas/etiologia , Staphylococcus aureus/isolamento & purificação , Idoso , Antibacterianos/uso terapêutico , Líquido da Lavagem Broncoalveolar/microbiologia , COVID-19/mortalidade , COVID-19/terapia , Feminino , Mortalidade Hospitalar , Hospitalização , Humanos , Unidades de Terapia Intensiva , Itália , Modelos Logísticos , Pulmão/microbiologia , Masculino , Pessoa de Meia-Idade , Escores de Disfunção Orgânica , Pneumonia Associada à Ventilação Mecânica/tratamento farmacológico , Pneumonia Associada à Ventilação Mecânica/etiologia , Estudos Prospectivos , Respiração Artificial , Infecções Estafilocócicas/tratamento farmacológico
12.
Talanta ; 232: 122448, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34074432

RESUMO

Staphylococcus aureus (S. aureus) is one of the most threatened food-borne pathogens. Thus, it is necessary to establish fast, portable and reliable tools to realize the identification of S. aureus. Herein, the authors describe an effective colorimetric-based biosensor for the detection of S. aureus in multiple types of samples. Initially, a nanozyme composed of gold and iron oxide nanoparticles was synthesized and further modified with S. aureus-specific aptamer via Au-S bond. By utilizing the intrinsic peroxidase-like activity of the above magnetic conjugates, 3,3',5,5'-tetramethylbenzidine (TMB) can be transferred to oxTMB by oxidation of hydrogen peroxide (H2O2), resulting in a visible blue color. However, the introduction of S. aureus can turn off the UV-vis absorbance signals of TMB-H2O2 system, due to the identification property of the nanozyme probe. Consequently, the optical density of the mixed solution measured at 652 nm decreased linearly as the concentration of S. aureus increased from 10 to 106 CFU mL-1, with the visible limit of detection as low as 10 CFU mL-1. The as-prepared sensor can detect S. aureus in spiked water, milk and urine samples quantitatively during 12 min without any pre-enrichment, separation or washing steps. In our perception, the one-step colorimetric assay show promise in practical on-site detection of S. aureus.


Assuntos
Colorimetria , Análise de Alimentos , Nanocompostos , Staphylococcus aureus/isolamento & purificação , Compostos Férricos , Ouro , Peróxido de Hidrogênio , Limite de Detecção , Peroxidase , Peroxidases
13.
Medicine (Baltimore) ; 100(18): e25867, 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33951001

RESUMO

RATIONALE: Ecthyma gangrenosum (EG) is an uncommon cutaneous infection usually associated with Pseudomonas aeruginosa bacteremia in immunocompromised patients, particularly those with underlying malignant diseases. Despite its rarity, especially in immunocompetent or nondiagnosed immunodeficiency patients, EG can present as the first manifestation of an underlying immunosuppression. PATIENT CONCERNS: A 42-year-old Japanese man was admitted to our hospital with a 3-day history of a painless red macule on his right forearm and fever. DIAGNOSES: Blood culture on admission revealed the presence of Pseudomonas aeruginosa, whereas pus culture of the skin lesion showed Pseudomonas aeruginosa and methicillin-susceptible Staphylococcus aureus positivity. INTERVENTIONS: Additional bone marrow aspirate examination and immunophenotyping were performed to confirm the diagnosis of acute promyelocytic leukaemia with PML-retinoic acid alpha receptor. OUTCOMES: The patient was successfully treated with a 14-day course of antibiotics, and no evidence of relapse was noted. The patient achieved complete remission after treatment for acute promyelocytic leukaemia. LESSONS: It should be kept in mind that EG is an important cutaneous infection that is typically associated with P aeruginosa bacteremia and the presence of underlying immunodeficiency, such as acute leukaemia.


Assuntos
Coinfecção/imunologia , Leucemia Promielocítica Aguda/diagnóstico , Infecções por Pseudomonas/imunologia , Pioderma Gangrenoso/imunologia , Infecções Cutâneas Estafilocócicas/imunologia , Adulto , Antibacterianos/uso terapêutico , Medula Óssea/patologia , Coinfecção/diagnóstico , Coinfecção/tratamento farmacológico , Coinfecção/microbiologia , Quimioterapia Combinada , Antebraço , Humanos , Hospedeiro Imunocomprometido , Leucemia Promielocítica Aguda/complicações , Leucemia Promielocítica Aguda/imunologia , Masculino , Infecções por Pseudomonas/diagnóstico , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/imunologia , Pseudomonas aeruginosa/isolamento & purificação , Pioderma Gangrenoso/diagnóstico , Pioderma Gangrenoso/tratamento farmacológico , Pioderma Gangrenoso/microbiologia , Pele/microbiologia , Infecções Cutâneas Estafilocócicas/diagnóstico , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Infecções Cutâneas Estafilocócicas/microbiologia , Staphylococcus aureus/imunologia , Staphylococcus aureus/isolamento & purificação , Resultado do Tratamento
14.
Biosensors (Basel) ; 11(5)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33947112

RESUMO

Over the past few decades, a significant increase in multi-drug-resistant pathogenic microorganisms has been of great concern and directed the research subject to the challenges that the distribution of resistance genes represent. Globally, high levels of multi-drug resistance represent a significant health threat and there is a growing requirement of rapid, accurate, real-time detection which plays a key role in tracking of measures for the infections caused by these bacterial strains. It is also important to reduce transfer of resistance genes to new organisms. The, World Health Organization has informed that millions of deaths have been reported each year recently. To detect the resistant organisms traditional detection approaches face limitations, therefore, newly developed technologies are needed that are suitable to be used in large-scale applications. In the present study, the aim was to design a surface plasmon resonance (SPR) sensor with micro-contact imprinted sensor chips for the detection of Staphylococcus aureus. Whole cell imprinting was performed by N-methacryloyl-L-histidine methyl ester (MAH) under UV polymerization. Sensing experiments were done within a concentration range of 1.0 × 102-2.0 × 105 CFU/mL. The recognition of S. aureus was accomplished by the involvement of microcontact imprinting and optical sensor technology with a detection limit of 1.5 × 103 CFU/mL. Selectivity of the generated sensor was evaluated through injections of competing bacterial strains. The responses for the different strains were compared to that of S. aureus. Besides, real experiments were performed with milk samples spiked with S. aureus and it was demonstrated that the prepared sensor platform was applicable for real samples.


Assuntos
Técnicas Biossensoriais , Staphylococcus aureus/isolamento & purificação , Biomimética , Histidina/análogos & derivados , Humanos , Metacrilatos , Ressonância de Plasmônio de Superfície
15.
Infect Dis Now ; 51(3): 304-307, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33934810

RESUMO

OBJECTIVES: To describe the efficacy and safety of prolonged cefazolin course for Staphylococcus infection and the emergence of multidrug-resistant bacteria carriage after treatment. METHODS: Monocentric retrospective cohort study of patients hospitalized for blood stream infections (BSI) and osteoarticular infections (OAI) by methicillin susceptible staphylococcal species treated with cefazolin from January 2015 to July 2017. Rectal and nasal swabs were performed at cefazolin initiation and end of treatment to detect respectively methicillin resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase (ESBL) producing bacteria. RESULTS: Fifty-eight patients were included, 41 had a bacteremia including 22 endocarditis and 22 OAI. Mean duration of treatment was 21.5 days at a mean daily dose of 6.5g/d. Fifty-five (94.5%) received combination therapy. Fifty-two (89.7%) of patients achieved bacteriological cure. Four patients were ESBL carriers at inclusion. No additional ESBL or MRSA were detected by end of treatment. CONCLUSION: Cefazolin appears as an effective and safe treatment for BSI or osteoarticular infection and does not appear to select MRSA or ESBL.


Assuntos
Antibacterianos/administração & dosagem , Cefazolina/administração & dosagem , Farmacorresistência Bacteriana Múltipla , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/tratamento farmacológico , Idoso , Bacteriemia/tratamento farmacológico , Doenças Ósseas Infecciosas/tratamento farmacológico , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Cloxacilina/administração & dosagem , Endocardite Bacteriana/tratamento farmacológico , Feminino , Humanos , Masculino , Meticilina/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Pessoa de Meia-Idade , Estudos Retrospectivos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação
19.
Medicine (Baltimore) ; 100(18): e25679, 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33950948

RESUMO

ABSTRACT: Uncomplicated bacteremia and catheter-related bloodstream infection (CRBSI) are frequently suggested as factors associated with low risk of infective endocarditis in Staphylococcus aureus bacteremia (SAB). Nevertheless, guidelines recommend that echocardiography in all patients with SAB. We evaluated the effects of echocardiography on patient outcomes. Patients with uncomplicated S. aureus CRBSI were retrospectively identified between January 2013 and June 2018 at a 1950-bed, tertiary-care university hospital. Treatment failure was defined as any case of relapse or all-cause death within 90 days. Of 890 SAB patients, 95 with uncomplicated S. aureus CRBSI were included. Thirty-two patients underwent echocardiography within 30 days of their first positive blood culture. Two patients who underwent echocardiography revealed right-sided infective endocarditis. One patient who did not undergo echocardiography experienced recurrent SAB (peripheral CRBSI) 85 days after his first positive blood culture. There were no SAB-related deaths. The Kaplan-Meier curves of treatment failure showed no significant differences between patients who did and did not undergo echocardiography (P = .77). In multivariable analysis, risk factors for treatment failure were liver cirrhosis (hazard ratio: 9.60; 95% confidence interval: 2.13-43.33; P = .003) and other prostheses (hazard ratio: 63.79; 95% confidence interval: 5.05-805.40; P = .001). This study did not verify the putative association between treatment failure and implementation of echocardiography in patients with uncomplicated S. aureus CRBSI. Given the low observed rates of adverse outcomes, routine echocardiography might not be obligatory and could be performed on an individual basis.


Assuntos
Bacteriemia/complicações , Infecções Relacionadas a Cateter/complicações , Ecocardiografia/estatística & dados numéricos , Endocardite Bacteriana/epidemiologia , Infecções Estafilocócicas/complicações , Adulto , Idoso , Antibacterianos/uso terapêutico , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Infecções Relacionadas a Cateter/diagnóstico , Infecções Relacionadas a Cateter/tratamento farmacológico , Infecções Relacionadas a Cateter/microbiologia , Ecocardiografia/normas , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/microbiologia , Endocardite Bacteriana/prevenção & controle , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Fatores de Risco , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/patogenicidade , Falha de Tratamento
20.
BMC Infect Dis ; 21(1): 312, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33794783

RESUMO

BACKGROUND: Staphylococcus aureus (S. aureus) bacteraemia is increasingly acquired from community settings and is associated with a mortality rate of up to 40% following complications. Identifying risk factors for complicated S. aureus bacteraemia would aid clinicians in targeting patients that benefit from expedited investigations and escalated care. METHODS: In this prospective observational cohort study, we aimed to identify risk factors associated with a complicated infection in community-onset S. aureus bacteraemia. Potential risk factors were collected from electronic medical records and included: - patient demographics, symptomology, portal of entry, and laboratory results. RESULTS: We identified several potential risk factors using univariate analysis. In a multiple logistic regression model, age, haemodialysis, and entry point from a diabetic foot ulcer were all significantly protective against complications. Conversely, an unknown entry point of infection, an entry point from an indwelling medical device, and a C-reactive protein concentration of over 161 mg/L on the day of admission were all significantly associated with complications. CONCLUSIONS: We conclude that several factors are associated with complications including already conducted laboratory investigations and portal of entry of infection. These factors could aid the triage of at-risk patients for complications of S. aureus bacteraemia.


Assuntos
Bacteriemia/diagnóstico , Proteína C-Reativa/análise , Staphylococcus aureus/isolamento & purificação , Adulto , Idoso , Bacteriemia/complicações , Bacteriemia/microbiologia , Estudos de Coortes , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Pneumonia/complicações , Pneumonia/diagnóstico , Estudos Prospectivos , Fatores de Risco , Dermatopatias/complicações , Dermatopatias/diagnóstico
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