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1.
Oral Dis ; 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-33191587

RESUMO

OBJECTIVES: This work aims to describe oral health conditions, eating habits, and oral hygiene in pediatric and adolescent patients with atopic dermatitis and correlate them with the severity of the Scoring Atopic Dermatitis (SCORAD). Also, we aim to estimate the effect of several variables on the diagnosis of dental caries in these patients. MATERIAL AND METHODS: A total of 92 children and adolescents with atopic dermatitis had their oral cavities examined. The effect of independent variables on the diagnosis of dental caries (outcome) was assessed using multiple binary logistic regression model. RESULTS: Mild patients presented higher score of decayed, missing, and filled teeth in permanent dentition than moderate patients (p = 0.040). In the multivariable regression final model, the covariates using inhaled corticoid (OR = 6.4; p = 0.003), type of teething [deciduous dentition (OR = 7.9; p = 0.027) and mixed dentition (OR = 10.5; p = 0.007)], and brushing quality [poor mechanical control (OR = 10.6; p < 0.0001)] demonstrated significant direct effect on the diagnosis of dental caries. CONCLUSIONS: Our findings suggest that the presence of dental biofilm, use of inhaled corticoid, and type of teething are related to the presence of caries in atopic dermatitis patients.

2.
Braz J Microbiol ; 51(4): 1509-1513, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33104973

RESUMO

Panton-Valentine leukocidin (PVL) is a Staphylococcus aureus virulence factor codified by lukSF-PV genes. Single-nucleotide polymorphisms (SNPs) at lukSF-PV genes can lead to two PVL sequence variants (R and H) generating different PVL isoforms. This study analyzed lukSF-PV genes SNPs among four different clonal lineages (STs/CC 1, 5, 8, and 30) of nine S. aureus isolated at Brazilian hospitals. The sequenced products showed SNPs at seven sites (positions 121, 470, 527, 663, 856, 1396, and 1729), leading to non-synonymous substitutions in all isolates investigated. Our findings showed new R and H isoforms variants in S. aureus isolated in Brazil and suggest a possible relationship between H2b isoform and the ST30/CC30 lineage.

3.
Braz J Microbiol ; 51(4): 1813-1817, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32822004

RESUMO

Human milk is the best nutrient for infants. The donor human milk is stored in a milk bank before pasteurization. However, the human milk is not sterile and could be colonized with different types of bacteria. Many studies have shown S. aureus to be the most prevalent potential pathogen detected in human milk. This study characterized 22 methicillin-resistant and methicillin-sensitive Staphylococcus aureus isolates from raw human milk for the presence of virulence genes and agr type. Moreover, the genotypic as identified characterization was realized. The presence of virulence genes sei, seg, sec, seh, and etb was identified in resistant and sensitive strains. We observed the predominance of agr type II. The presence of SCCmec IV (67%, 4/6) and V (33%, 2/6) characterized resistant strains as CA-MRSA. Endemic lineages detected (ST1635/CC5-t002, ST5/CC5-t002, ST72/CC5-t126, ST1/CC1-t127, ST45/CC45-t065, and ST398/t1451) could be related to epidemic clones, such as USA800/ST5, USA700/ST72, USA400/ST1, USA600/ST45, and ST398. This study made it possible to understand the characteristics of virulence and clonality of some strains that circulate in breast milk in our region. The discovery of human milk colonization by MSSA and MRSA strains with molecular characteristics similar to infectious clones spread globally demonstrates the importance of monitoring strains that can spread and cause serious infections.

5.
Nanotechnology ; 31(37): 375101, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32470951

RESUMO

Bacterial infections represent one of the leading causes of mortality in the world. Among causative pathogens, S. aureus is prominently known as the underlying cause of many multidrug resistant infections that are often treated with the first-line choice antibiotic vancomycin (VCM). Loading antibiotics into polymeric nanoparticles (Np) displays promise as an alternative method to deliver therapy due to the greater access and accumulation of the antibiotic at the site of the infection as well as reducing toxicity, irritation and degradation. The aim of this work was to prepare, characterize and evaluate VCM-loaded nanoparticles (VNp) for use against S. aureus strains. Moreover, conjugation of Nps with holo-transferrin (h-Tf) was investigated as an approach for improving targeted drug delivery. VNp were prepared by double emulsion solvent evaporation method using PLGA and PVA or DMAB as surfactants. The particles were characterized for size distribution, Zeta Potential, morphology by transmission electron microscopy, encapsulation yield and protein conjugation efficiency. Process yield and drug loading were also investigated along with an in vitro evaluation of VNp antimicrobial effects against S. aureus strains. Results showed that Np were spontaneously formed with a mean diameter lower than 300 nm in a narrow size distribution that presented a spherical shape. The bioconjugation with h-Tf did not appear to increase the antimicrobial effect of VNp. However, non-bioconjugated Np presented a minimal inhibitory concentration lower than free VCM against a MRSA (Methicillin-resistant S. aureus) strain, and slightly higher against a VISA (VCM intermediate S. aureus) strain. VNp without h-Tf showed potential to assist in the development of new therapies against S. aureus infections.

6.
BMC Infect Dis ; 20(1): 74, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31973753

RESUMO

BACKGROUND: Staphylococcus aureus is one of the major causes of bloodstream infections (BSI) worldwide, representing a major challenge for public health due to its resistance profile. Higher vancomycin minimum inhibitory concentrations (MIC) in S. aureus are associated with treatment failure and defining optimal empiric options for BSIs in settings where these isolates are prevalent is rather challenging. In silico pharmacodynamic models based on stochastic simulations (Monte Carlo) are important tools to estimate best antimicrobial regimens in different scenarios. We aimed to compare the pharmacodynamic profiles of different antimicrobials regimens for the treatment of S. aureus BSI in an environment with high vancomycin MIC. METHODS: Steady-state drug area under the curve ratio to MIC (AUC/MIC) or the percent time above MIC (fT > MIC) were modeled using a 5000-patient Monte Carlo simulation to achieve pharmacodynamic exposures against 110 consecutive S. aureus isolates associated with BSI. RESULTS: Cumulative fractions of response (CFRs) against all S. aureus isolates were 98% for ceftaroline; 79% and 92% for daptomycin 6 mg/kg q24h and for the high dose of 10 mg/kg q24h, respectively; 77% for linezolid 600 mg q12h when MIC was read according to CLSI M100-S26 instructions, and 64% when MIC was considered at the total growth inhibition; 65% and 86% for teicoplanin, three loading doses of 400 mg q12 h followed by 400 mg q24 h and for teicoplanin 400 mg q12 h, respectively; 61% and 76% for vancomycin 1000 mg q12 h and q8 h, respectively. CONCLUSIONS: Based on this model, ceftaroline and high-dose daptomycin regimens delivered best pharmacodynamic exposures against S. aureus BSIs. Teicoplanin higher dose regimen achieved the best CFR (86%) among glycopeptides, although optimal threshold was not achieved, and vancomycin performance was critically affected by the S. aureus vancomycin MIC ≥2 mg/L. Linezolid effectiveness (CFR of 73%) is also affected by high prevalence of isolates with linezolid MIC ≥2 mg/L. These data show the need to continually evaluate the pharmacodynamic profiles of antimicrobials for empiric treatment of these infections.


Assuntos
Antibacterianos/farmacologia , Bacteriemia/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Vancomicina/farmacologia , Antibacterianos/farmacocinética , Bacteriemia/microbiologia , Brasil , Cefalosporinas/farmacocinética , Cefalosporinas/farmacologia , Daptomicina/farmacocinética , Daptomicina/farmacologia , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Método de Monte Carlo , Estudos Retrospectivos , Infecções Estafilocócicas/microbiologia , Vancomicina/farmacocinética
7.
Appl Environ Microbiol ; 86(5)2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31862721

RESUMO

The microbiota influences host health through several mechanisms, including protecting it from pathogen colonization. Staphylococcus epidermidis is one of the most frequently found species in the skin microbiota, and its presence can limit the development of pathogens such as Staphylococcus aureus S. aureus causes diverse types of infections ranging from skin abscesses to bloodstream infections. Given the increasing prevalence of S. aureus drug-resistant strains, it is imperative to search for new strategies for treatment and prevention. Thus, we investigated the activity of molecules produced by a commensal S. epidermidis isolate against S. aureus biofilms. We showed that molecules present in S. epidermidis cell-free conditioned media (CFCM) caused a significant reduction in biofilm formation in most S. aureus clinical isolates, including all 4 agr types and agr-defective strains, without any impact on growth. S. epidermidis molecules also disrupted established S. aureus biofilms and reduced the antibiotic concentration required to eliminate them. Preliminary characterization of the active compound showed that its activity is resistant to heat, protease inhibitors, trypsin, proteinase K, and sodium periodate treatments, suggesting that it is not proteinaceous. RNA sequencing revealed that S. epidermidis-secreted molecules modulate the expression of hundreds of S. aureus genes, some of which are associated with biofilm production. Biofilm formation is one of the main virulence factors of S. aureus and has been associated with chronic infections and antimicrobial resistance. Therefore, molecules that can counteract this virulence factor may be promising alternatives as novel therapeutic agents to control S. aureus infections.IMPORTANCE S. aureus is a leading agent of infections worldwide, and its main virulence characteristic is the ability to produce biofilms on surfaces such as medical devices. Biofilms are known to confer increased resistance to antimicrobials and to the host immune responses, requiring aggressive antibiotic treatment and removal of the infected surface. Here, we investigated a new source of antibiofilm compounds, the skin microbiome. Specifically, we found that a commensal strain of S. epidermidis produces molecules with antibiofilm activity, leading to a significant decrease of S. aureus biofilm formation and to a reduction of previously established biofilms. The molecules potentiated the activity of antibiotics and affected the expression of hundreds of S. aureus genes, including those associated with biofilm formation. Our research highlights the search for compounds that can aid us in the fight against S. aureus infections.


Assuntos
Biofilmes/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/química , Fatores de Virulência/fisiologia , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/fisiologia
8.
J Clin Periodontol ; 46(12): 1192-1204, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31380576

RESUMO

BACKGROUND AND AIM: This study compared the oral bacteriome between HIV-1-infected and non-HIV-1-infected Brazilian children/teenagers. METHODS: Whole saliva, biofilm from the dorsal surface of the tongue and biofilm from supragingival and subgingival sites were collected from 27 HIV-1-infected and 30 non-HIV-1-infected individuals. Bacterial genomic DNA was extracted and 16S rRNA genes were sequenced using next-generation sequencing technology (Ion Torrent). RESULTS: In the supragingival biofilm, the phylum Firmicutes and genus Streptococcus sp. were more frequent in HIV-1-infected (95% and 78%, respectively) than in non-HIV-1-infected individuals (40% and 24%, respectively). In the subgingival biofilm of HIV-infected participants, the relative abundance of the Veillonella sp. and Prevotella sp. genera were higher than in non-HIV-1-infected participants. On the tongue, the genera with greater relative abundance in HIV-1-infected individuals were Neisseria sp. (21%). In saliva, the difference of the genus Prevotella sp. between non-HIV-1-infected and HIV-1-infected individuals was 15% and 7%, respectively. The Chao index revealed an increase in the richness of both sub- and supragingival biofilms in the HIV-1-infected samples compared with non-HIV-1-infected samples. CONCLUSION: HIV-1-infected children/teenagers have a higher frequency of the phyla Firmicutes and genus Streptococcus, and their oral microbiome shows more complexity than that of non-HIV-1-infected children/teenagers.


Assuntos
HIV-1 , Adolescente , Biofilmes , Brasil , Criança , DNA Bacteriano , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , RNA Ribossômico 16S , Análise de Sequência de DNA
9.
Sci Rep ; 9(1): 11736, 2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31409863

RESUMO

Staphylococcus hominis is part of the normal human microbiome. Two subspecies, S. hominis hominis (Shh) and S. hominis novobiosepticus (Shn), have clinical significance. Forty-nine S. hominis isolates were analyzed by the MicroScan automated system, SDS-PAGE and MALDI-TOF methods, followed by partial sequencing of the 16S rDNA gene. The trehalose fermentation test, disk diffusion and broth microdilution tests were used to identify (novobiocin test) and access the susceptibility to oxacillin and vancomycin of isolates. The SCCmec elements and genomic diversity were evaluated by PCR and PFGE methods, respectively. Profiles of 28 (57%; 8 Shh and 20 Shn) isolates corroborated with the results found in all the applied methods of identification. The remaining 21 (43%) isolates were phenotypically identified as Shh by MicroScan; however, they were identified as Shn by SDS-PAGE and mass spectral, and confirmed by 16S rDNA sequencing. Among 41 isolates identified as Shn by the molecular and mass spectrometry methods, 19 (41%) were novobiocin-sensitive, and the trehalose test indicated 11 positive isolates, which are considered atypical phenotypic results for this subspecies. In addition, 92.7% of the isolates identified as Shn by these methods carried mecA gene, while only 12.5% of the Shh isolates were positive. Together, the results highlighted the SDS-PAGE and MALDI-TOF MS methods as promising tools for discriminating S. hominis subspecies.


Assuntos
Proteínas de Bactérias/metabolismo , Eletroforese em Gel de Poliacrilamida , Proteoma , Proteômica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Staphylococcus hominis/classificação , Staphylococcus hominis/metabolismo , Humanos , Proteômica/métodos
10.
J Glob Antimicrob Resist ; 19: 236-240, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31176072

RESUMO

OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) is an important causative agent of nosocomial infections. Mutations in the quinolone resistance-determining regions (QRDRs) of the gyr and par genes have been described. This study aimed to characterise phenotypic and genotypic fluoroquinolone resistance in 69 MRSA isolates of different clonal lineages from hospitals in Rio de Janeiro, Brazil. METHODS: QRDR mutations in the gyrA, gyrB, parC and parE genes were detected by DNA sequencing. Minimum inhibitory concentrations (MICs) for ciprofloxacin and moxifloxacin were determined by broth microdilution. The occurrence of associations between mutations and MICs among the different clonal lineages of MRSA isolates was then verified. RESULTS: Most isolates from the USA400/ST1/SCCmec IV lineage, but mainly USA100/ST5/SCCmec II isolates, which have been more recently found in Rio de Janeiro hospitals, showed different patterns of mutations, including double mutation in the QRDR of parC (Ser-80â¿¿â¿¿â¿¿Tyr and Glu-84â¿¿â¿¿â¿¿Lys/Gly) and/or gyrA (Ser-84â¿¿â¿¿â¿¿Leu and/or Glu-88â¿¿â¿¿â¿¿Lys) associated with higher moxifloxacin and ciprofloxacin MICs (MIC90, â¿¥8â¿¿mg/L and 256â¿¿mg/L, respectively). On the other hand, all USA800/ST5/SCCmec IV and the BEC/ST239/SCCmec III isolates, which have disappeared from hospitals, showed single mutations in parC (Ser-80â¿¿â¿¿â¿¿Phe) and gyrA (Ser-84â¿¿â¿¿â¿¿Leu or Glu-88â¿¿â¿¿â¿¿Gly) and lower fluoroquinolones MICs (MIC90, â¿¥2â¿¿mg/L and â¿¥16â¿¿mg/L). CONCLUSION: This study highlights an increase in the number and types of mutations in the QRDRs ofgyrA and parC associated with high fluoroquinolones MICs that may be related to changes in the epidemiological profile of MRSA isolates from hospitals in Rio de Janeiro.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Mutação , Quinolonas/farmacologia , Brasil/epidemiologia , DNA Girase/genética , DNA Topoisomerase IV/genética , Genótipo , Hospitais/estatística & dados numéricos , Humanos , Testes de Sensibilidade Microbiana , Fenótipo , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia
11.
J Infect Dev Ctries ; 13(9): 810-816, 2019 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32074090

RESUMO

INTRODUCTION: Staphylococcal colonization is a risk factor for healthcare-associated infections, which are frequent in Neonatal Intensive Care Units (NICU). This study analyzed microbiology, epidemiology and clinical aspects of Staphylococcus spp. colonizing neonates. METHODOLOGY: Nasal or periumbilical swabs were evaluated from 175 newborns admitted to a NICU of a Rio de Janeiro hospital from March to September 2009. Clinical data were obtained from the medical records. SCCmec typing and the mecA and Panton-Valentine Leukocidin (PVL) genes were detected by PCR. Clonal diversity was evaluated by pulsed-field gel electrophoresis. RESULTS: Staphylococcus spp. isolates were detected in 98 (56%) neonates, 66.3% of them had birth weight ≤ 2500 g, 62.2% were preterm (˂ 37 weeks) and the mean length of hospitalization was 14.9 days. Among the 133 isolates identified, 48.1% were S. epidermidis, 23.3% S. haemolyticus and 13.5% S. aureus. Methicillin-resistant Staphylococcus isolate was detected in 77.6% of neonates. The methicillin-resistant S. aureus isolates carried the SCCmec type IV, while 94.6% of S. epidermidis and 85.7% of S. haemolyticus presented non-typeable cassettes. Among the S. aureus, 55.6% had PVL genes and the USA800 genotype was prevalent. Two genotypes of S. epidermidis and one of S. haemolyticus clustered 42.2% and 25.8% of the isolates, respectively. S haemolyticus colonization was associated with the use of parenteral nutrition and mechanical ventilation. CONCLUSION: High rate of neonates colonized by methicillin-resistant Staphylococcus species and the permanence of clones circulating in the NICU highlight the importance for continuous and preventive surveillance in this high-risk population.


Assuntos
Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Brasil/epidemiologia , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia
12.
Clin Oral Investig ; 23(6): 2583-2591, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30315423

RESUMO

OBJECTIVE: The aim of this study was to evaluate microbiological changes, oral soft tissue toxicity, and caries-preventive effect of an experimental titanium tetrafluoride (TiF4) varnish compared with a commercially available fluoride varnish (NaF), using in situ and in vivo models. MATERIALS AND METHODS: The treatment groups were the following: TiF4 varnish (experimental varnish), Duraphat® (fluoride positive control), placebo varnish (no fluoride), and no treatment (negative control). The varnishes were applied once over the enamel surface using a microbrush. For the in vivo study, 48 Wistar rats were infected with Streptococcus sobrinus 6715, received a treatment, and were submitted to a cariogenic challenge. After 4 weeks, S. sobrinus, oral soft tissue toxicity, presence, and severity of caries were evaluated. For the in situ study, 12 volunteers took part in this randomized crossover, double-blind study performed in four phases of 14 days each. They used intraoral appliances containing four enamel specimens that received the varnish according treatment group. After 24 h, the varnish was removed and plaque accumulation was allowed. A 20% sucrose solution was dripped over the enamel blocks (10×/day for 5 min each). Total streptococci, S. mutans, Lactobacillus, Candida spp. counts, and presence of white spot lesions were evaluated. Lesion depth was also quantified by micro-CT. RESULTS: For the in vivo study, the fluoride (F-varnishes) showed a statistically significant reduction in the percentage of S. sobrinus compared to the negative control (p < 0.05). Toxicological analysis revealed no abnormalities in oral tissues of rats from all groups, and both F-varnishes reduced the number and severity of caries lesions, without significant differences (p < 0.05). No statistical differences in microbiological counts were seen for the in situ experiment (p > 0.05). However, the specimens treated with TiF4 exhibited lower percentage of white spot lesions and the lesion depth was significantly reduced by F-varnishes (p < 0.05). CONCLUSIONS: F-varnishes showed reduction in the percentage of S. sobrinus in vivo, no oral soft tissue toxicity, and a caries-preventive effect in vivo and in situ. CLINICAL RELEVANCE: NaF varnish is largely used due its capacity to form CaF2-like layer on enamel. Therefore, development of studies focused on other fluoride compounds such as a TiF4 varnish, which may have greater efficacy than NaF against tooth demineralization, is important.


Assuntos
Cariostáticos/farmacologia , Cárie Dentária/prevenção & controle , Fluoretos/farmacologia , Titânio/farmacologia , Animais , Estudos Cross-Over , Método Duplo-Cego , Feminino , Fluoretos Tópicos/farmacologia , Humanos , Ratos , Ratos Wistar , Fluoreto de Sódio/farmacologia
13.
J Pept Sci ; 24(11): e3129, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30325566

RESUMO

Eight molecules, four peptides (SPs) and four lipopeptides (LPs) derived by rational design from surfactin, a well-known secreted biosurfactant from Bacillus subtilis, were produced employing Fmoc-based solid-phase synthesis. These new peptides were tested to evaluate their potential biosurfactant and biological activities, aiming at possible applications in industrial, biological, pharmaceutical, and medical use. Five molecules (SP1, SP2, SP4, LP5, and LP8) presented potential for medical uses, mainly due to their drug delivery properties as suggested by their synergistic activity with the antibiotic vancomycin against Staphylococcus aureus. All synthetic peptides showed low toxicity against Vero cell cultures, in assays of hemolysis, and in different cytotoxicity assays. In addition, we found that three peptides (SP1, LP6, and LP7) had potential technological and industrial use because of their emulsifying capacity, low toxicity, and ability to physically stabilize solutions. These novel molecules retained some properties of the parental molecule (surfactin, which was originally obtained through nonribosomal synthesis in Bacillus subtilis) but have the advantage of being linear peptides, which can be produced at large scales through the use of conventional heterologous protein expression protocols.


Assuntos
Bacillus subtilis/metabolismo , Lipopeptídeos/síntese química , Peptídeos Cíclicos/química , Peptídeos/síntese química , Técnicas de Síntese em Fase Sólida/métodos , Animais , Bacillus subtilis/química , Proteínas de Bactérias/química , Chlorocebus aethiops , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Sinergismo Farmacológico , Emulsificantes/síntese química , Emulsificantes/química , Emulsificantes/farmacologia , Humanos , Lipopeptídeos/química , Lipopeptídeos/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Vancomicina/farmacologia , Células Vero
14.
PLoS Negl Trop Dis ; 12(9): e0006739, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30212460

RESUMO

BACKGROUND: Chagas disease is caused by the parasite Trypanosoma cruzi and is transmitted through triatomines (Hemiptera: Reduviidae). In the last year, many studies of triatomine gut microbiota have outlined its potential role in modulating vector competence. However, little is known about the microbiota present in the salivary glands of triatomines. Bacterial composition of salivary glands in selected triatomine species was investigated, as well as environmental influences on the acquisition of bacterial communities. METHODOLOGY/PRINCIPAL FINDINGS: The diversity of the bacterial communities of 30 pairs of salivary glands of triatomines was studied by sequencing of the V1- V3 variable region of the 16S rRNA using the MiSeq platform (Illumina), and bacteria isolated from skin of three vertebrate hosts were identified based on 16S rRNA gene sequence analysis (targeting the V3-V5 region). In a comparative analysis of microbiota in the salivary glands of triatomine species, operational taxonomic units belonging to Arsenophonous appeared as dominant in Triatoma spp (74% of the total 16S coverage), while these units belonging to unclassified Enterobacteriaceae were dominant in the Rhodnius spp (57% of the total 16S coverage). Some intraspecific changes in the composition of the triatomine microbiota were observed, suggesting that some bacteria may have been acquired from the environment. CONCLUSIONS AND SIGNIFICANCE: Our study revealed the presence of a low-diversity microbiota associated to the salivary glands of the evaluated triatomines. The predominant bacteria genera are associated with triatomine genera and the bacteria can be acquired in the environment in which the insects reside. Further studies are necessary to determine the influence of bacterial communities on vector competence.


Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Biota , Insetos Vetores/microbiologia , Glândulas Salivares/microbiologia , Triatominae/microbiologia , Animais , Bactérias/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Humanos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Pele/microbiologia , Vertebrados
15.
Am J Infect Control ; 45(11): 1190-1193, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28751036

RESUMO

BACKGROUND: Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are associated with greater mortality and morbidity; however, risk factors for community-acquired infections caused by MRSA have not been established. Therefore, community patients who are admitted to hospitals without the necessary contact precautions and are infected with community-acquired lineages eventually cause these lineages to spread to these settings. The aim of this study was to detect community-acquired lineages of MRSA in patients on admission to a Brazilian teaching hospital. METHODS: The antimicrobial susceptibility of the MRSA isolates from nasal swabs was evaluated as was the molecular characteristics of the staphylococcal cassette chromosome mec (SCCmec). The clonality was determined using pulsed-field gel electrophoresis and multilocus sequence type analysis. RESULTS: A total of 702 patients were evaluated between March 2012 and March 2013; 180 (25%) of them were colonized by S aureus, and 21 (3%) were MRSA. The SCCmec IV/USA1100/sequence type (ST) 30 was the predominant MRSA lineage (42.8%), followed by SCCmec IV/USA800/ST5 (23.8%). CONCLUSIONS: The occurrence of MRSA colonization was very low, and only 1 patient from cardiac surgery developed an infection, which was caused by an SCCmec II/USA100/ST5 isolate. Screening for MRSA colonization on admission does not seem to be productive; however, for populations submitted to specific surgeries, active surveillance should be implemented.


Assuntos
Infecção Hospitalar/epidemiologia , Hospitais de Ensino/estatística & dados numéricos , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas/epidemiologia , Adulto , Idoso , Brasil/epidemiologia , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/genética , Pessoa de Meia-Idade , Admissão do Paciente/estatística & dados numéricos , Estudos Prospectivos , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Adulto Jovem
16.
Acta Odontol Scand ; 75(6): 446-452, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28585889

RESUMO

OBJECTIVE: To compare the risk for caries in children as determined by Cariogram® software (CS; Stockholm, Sweden) with and without its microbiological component and by a form based on Cariogram® (FBC). METHODS: Children (n = 28) aged 3-9 years were included. Data were collected clinically and from anamnesis. The salivary levels of Streptococcus mutans (SM) were evaluated. A linear regression model was used to determine which variables were predictive for each type of risk analysis. Caries risk was the dependent variable and the independent variables were caries experience, related disease, plaque amount, diet frequency, salivary levels of SM, fluoride sources and clinical judgment. A paired Student t-test was used for the following comparisons: (a) CS with and without SM; (b) CS without SM and FBC; (c) CS with SM and FBC. RESULTS: The mean dmft/DMFT was 5.56 ± 2.51. There was no difference between the methods (p < .05). Regardless of caries risk, the children presented the same levels of SM (p = .889). Caries experience, plaque amount, diet frequency and fluoride sources were predictors of caries risk in all assessment methods. Clinical judgment was a significant predictor in CS. CONCLUSIONS: Caries experience, plaque amount, diet frequency and fluoride sources are valuable predictors of caries risk; microbiological tests are not necessary for evaluating caries risk in children, which can be assessed similarly by CS without SM and FBC.


Assuntos
Suscetibilidade à Cárie Dentária , Cárie Dentária/microbiologia , Placa Dentária/microbiologia , Criança , Pré-Escolar , Índice CPO , Feminino , Humanos , Masculino , Kit de Reagentes para Diagnóstico/microbiologia , Medição de Risco/métodos , Streptococcus mutans/isolamento & purificação , Suécia
17.
Acta Odontol Scand ; 75(6): 423-428, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28580816

RESUMO

OBJECTIVE: This study investigated the presence of Enterococcus faecalis in primary teeth with primary root canal infections and related to the possible failure of pulpectomy outcome after 36 months. MATERIAL AND METHODS: Root canal samples were obtained from 25 out of 244 patients using the sterile paper cone method. The identification of E. faecalis was done with culture and molecular tests using species-specific 16S rRNA gene-based polymerase chain reaction (PCR). After 36 months, the pulpectomy outcome was evaluated. RESULTS: Enterococcus faecalis was found in five (20%) samples, and dental caries were the cause of primary infection in all of them. Pulpectomy outcome was evaluated only in teeth that completed the entire clinical protocol and were followed up to 36 months (n = 8). From these, 75% (n = 6) were successful and 25% (n = 2) failed. E. faecalis was present in 50% of both successful and failed cases. CONCLUSIONS: Enterococcus faecalis was not related to the failure of endodontic treatment of primary teeth.


Assuntos
Cárie Dentária/microbiologia , Cavidade Pulpar/microbiologia , Enterococcus faecalis/isolamento & purificação , Tratamento do Canal Radicular , Dente Decíduo/microbiologia , Humanos , Masculino , Reação em Cadeia da Polimerase
18.
BMC Microbiol ; 17(1): 15, 2017 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-28086793

RESUMO

BACKGROUND: Staphylococcus epidermidis is an opportunistic pathogen involved in hospital-acquired infections, particularly in those related to medical devices. This study characterized 50 genetically unrelated S. epidermidis isolates from bloodstream infections (BSIs, n = 31) and nares (n = 19) of neonates in relation to staphylococcal chromosomal cassette mec (SCCmec) type, biofilm production and associated genes, and the arginine catabolic mobile elements (ACME), in order to detect virulence factors that could discriminate a potential invasiveness isolate or predict an increasing pathogenicity. RESULTS: Isolates from both groups showed no difference for biofilm production and ACME genes detection. However, BSI isolates harbored more frequently the sdrF and sesI genes (p < 0.05), whereas biofilm producer isolates were associated with presence of the aap gene. The sdrF gene was also significantly more in the biofilm producer isolates from BSI. The SCCmec type IV and the ccr2 complex were related to BSI isolates (p < 0.05), while 83% of the nasal isolates were non-typeable for the SCCmec elements, with the mec complex and ccr undetectable as the most frequent profile. CONCLUSIONS: Despite the great clonal diversity displayed by S. epidermidis isolates from neonates, BSI isolates harbored more frequently the sdrF and sesI adhesin genes, while nasal isolates were very variable in SCCmec composition. These aspects could be advantageous to improve colonization in the host increasing its pathogenicity.


Assuntos
Resistência a Meticilina/genética , Cavidade Nasal/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/isolamento & purificação , Staphylococcus epidermidis/patogenicidade , Virulência/genética , Adesinas Bacterianas/genética , Arginina/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Biofilmes/crescimento & desenvolvimento , Brasil/epidemiologia , DNA Bacteriano/genética , Variação Genética , Humanos , Recém-Nascido , Tipagem de Sequências Multilocus , Fenótipo , Reação em Cadeia da Polimerase , Infecções Estafilocócicas/sangue , Infecções Estafilocócicas/epidemiologia , Staphylococcus epidermidis/efeitos dos fármacos , Fatores de Virulência/genética
19.
Braz J Infect Dis ; 21(2): 185-189, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27875687

RESUMO

Staphylococcus aureus is an important cause of bloodstream infections. Therefore, the main purpose of this work was to characterize a collection of 139 S. aureus isolates from bloodstream infections in two public hospitals in relation to their antimicrobial susceptibility profile, staphylococcal cassette chromosome mec types, and clonal relationship. Methicillin resistance and resistance to other 12 agents were accessed by the disk diffusion test. Minimum inhibitory concentration to mupirocin was also determined. The SCCmec types were accessed by multiplex PCR, and the clonal relationship was determined by pulsed field gel electrophoresis method and restriction modification system characterization. Besides, multilocus sequence typing was performed for representative methicillin-resistant S. aureus isolates. The military hospital showed a dissemination of the New York/Japan (USA100/ST5/CC5/SCCmecII) lineage associated to multidrug resistance, including mupirocin resistance, and the teaching hospital presented polyclonal and non-multidrug resistant MRSA isolates. Complete substitution of the Brazilian endemic clone by other lineages was found in both hospitals. These findings can highlight differences in policy control and prevention of infections used in the hospitals and a change in the epidemiological profile of MRSA in Brazilian hospitals, with the replacement of BEC, a previously well-established clone, by other lineages.


Assuntos
Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Técnicas de Tipagem Bacteriana , Brasil , DNA Bacteriano/genética , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Eletroforese em Gel de Campo Pulsado , Genótipo , Hospitais Públicos , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Tipagem de Sequências Multilocus , Mupirocina/farmacologia
20.
PLoS One ; 11(8): e0160506, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27575698

RESUMO

This study analyzed clinical and microbiological characteristics of heteroresistant (hVISA) and vancomycin-intermediate Staphylococcus aureus (VISA) from bloodstream infections (BSI) in a Brazilian teaching hospital, between 2011 and 2013. Minimum inhibitory concentrations (MIC) of antimicrobials were determined by broth microdilution method and SCCmec was detected by PCR. Isolates with a vancomycin MIC ≥ 2mg/L were cultured on BHI agar with 3, 4 or 6 mg/L (BHIa3, BHIa4 or BHIa6) of vancomycin and BHIa4 with casein (BHIa4ca). Macromethod Etest® and Etest® Glicopeptides Resistance Detection were also used. VISA and hVISA isolates were confirmed by the population analysis profile then typed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Medical data from the patients were obtained from their medical records. Among 110 consecutive isolates, 31 (28%) were MRSA and carried the SCCmec type II (15 isolates) or IV (16 isolates). Vancomycin MIC50 and MIC90 were 1 and 2 mg/L, respectively. MRSA isolates had increased non-susceptibility to daptomycin (p = 0.0003). Six (5%) isolates were VISA, four of which were MRSA, three SCCmec type II/USA100/ST5 and one type IV/USA800/ST3192. One MRSA SCCmec II isolate grew on agar BHIa3, BHIa4 and BHIa4ca, and it was confirmed as hVISA. Among the six VISA isolates, five (83%) grew on BHIa3 and three (50%) on BHI4ca. Four of the six VISA isolates and the one hVISA isolate were from patients who had undergone dialysis. Thus, a possible dissemination of the SCCmec II/USA100/ST5 lineage may have occurred in the hospital comprising the VISA, hVISA and daptomycin non-susceptible S. aureus Brazilian isolates from health care associated bloodstream infections.


Assuntos
Antibacterianos/farmacologia , Bacteriemia/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Resistência a Vancomicina , Infecção Hospitalar/microbiologia , Feminino , Hospitais de Ensino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Diálise Renal/efeitos adversos , Staphylococcus aureus/classificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética
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