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1.
Sci Rep ; 14(1): 14961, 2024 06 28.
Article in English | MEDLINE | ID: mdl-38942787

ABSTRACT

Methicillin-resistant Staphylococcus (MRS) has been associated with neonatal infections, with colonization of the anovaginal tract being the main source of vertical transmission. The COVID-19 pandemic has altered the frequency of antibiotic usage, potentially contributing to changes in the dynamics of bacterial agents colonizing humans. Here we determined MRS colonization rates among pregnant individuals attending a single maternity in Rio de Janeiro, Brazil before (January 2019-March 2020) and during (May 2020-March 2021) the COVID-19 pandemic. Anovaginal samples (n = 806 [521 samples before and 285 during the pandemic]) were streaked onto chromogenic media. Colonies were identified by MALDI-TOF MS. Detection of mecA gene and SCCmec typing were assessed by PCR and antimicrobial susceptibility testing was done according to CLSI guidelines. After the onset of the pandemic, MRS colonization rates increased significantly (p < 0.05) from 8.6% (45) to 54.7% (156). Overall, 215 (26.6%) MRS isolates were detected, of which S. haemolyticus was the most prevalent species (MRSH, 84.2%; 181 isolates). SCCmec type V was the most frequent among MRS (63.3%; 136), and 31.6% (68) of MRS strains had a non-typeable SCCmec, due to new combinations of ccr and mecA complexes. Among MRS strains, 41.9% (90) were resistant to at least 3 different classes of antimicrobial agents, and 60% (54) of them were S. haemolyticus harboring SCCmec V. MRS colonization rates and the emergence of multidrug-resistant variants detected in this study indicate the need for continuing surveillance of this important pathogen within maternal and child populations.


Subject(s)
COVID-19 , Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections , Humans , Female , Pregnancy , COVID-19/epidemiology , COVID-19/virology , Staphylococcal Infections/epidemiology , Staphylococcal Infections/microbiology , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/drug effects , Adult , Brazil/epidemiology , Pregnancy Complications, Infectious/microbiology , Pregnancy Complications, Infectious/epidemiology , Anti-Bacterial Agents/pharmacology , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Microbial Sensitivity Tests , Pandemics , Vagina/microbiology
3.
J Periodontal Res ; 51(1): 95-102, 2016 02.
Article in English | MEDLINE | ID: mdl-26040412

ABSTRACT

BACKGROUND AND OBJECTIVE: To compare the subgingival microbial diversity between non-HIV-infected and HIV-infected individuals with chronic periodontitis using denaturing gradient gel electrophoresis (DGGE). MATERIAL AND METHODS: Thirty-two patients were selected: 11 were HIV-infected and 21 were non-HIV-infected, and all had chronic periodontitis. Periodontal measurements included probing depth, clinical attachment level, visible supragingival biofilm and bleeding on probing. Subgingival biofilm samples were collected from periodontal sites (50% with probing depth ≤ 4 mm and 50% with probing depth ≥ 5 mm) and whole-genomic-amplified DNA was obtained. The DNA samples were subjected to amplification of a 16S rRNA gene fragment using universal bacterial primers, followed by DGGE analysis of the amplified gene sequences. RESULTS: The non-HIV-infected group presented higher mean full-mouth visible supragingival biofilm (p = 0.004), bleeding on probing (p = 0.006), probing depth (p < 0.001) and clinical attachment level (p = 0.001) in comparison with the HIV-infected group. DGGE analysis revealed 81 distinct bands from all 33 individuals. Banding profiles revealed a higher diversity of the bacterial communities in the subgingival biofilm of HIV-infected patients with chronic periodontitis. Moreover, cluster and principal component analyses demonstrated that the bacterial community profiles differed between these two conditions. High interindividual and intra-individual variability in banding profiles were observed for both groups. CONCLUSION: HIV-infected patients with chronic periodontitis present greater subgingival microbial diversity. In addition, the bacterial communities associated with HIV-infected and non-HIV-infected individuals are different in structure.


Subject(s)
Chronic Periodontitis , Adult , Brazil , DNA, Bacterial , Dental Plaque , HIV Infections , Humans , Periodontal Pocket , RNA, Ribosomal, 16S
4.
Braz. j. med. biol. res ; 48(7): 588-594, 07/2015. tab
Article in English | LILACS | ID: lil-751349

ABSTRACT

Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmec typing, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureus isolates from skin infections. Methicillin-resistant S. aureus (MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 μg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD.


Subject(s)
Animals , Male , Mice , Rats , Kidney Diseases/metabolism , Kidney/metabolism , Podocytes/metabolism , Signal Transduction , Cells, Cultured , Cyclic AMP Response Element-Binding Protein/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Gene Expression , Gene Regulatory Networks , Immunoblotting , Kidney Diseases/chemically induced , Kidney Diseases/genetics , Kidney/pathology , Kidney/physiopathology , Microscopy, Electron , Membrane Proteins/genetics , Membrane Proteins/metabolism , Microfilament Proteins/genetics , Microfilament Proteins/metabolism , Puromycin , Podocytes/pathology , Podocytes/ultrastructure , Proteomics/methods , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction
5.
Braz J Med Biol Res ; 48(7): 588-94, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25992644

ABSTRACT

Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmec typing, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureus isolates from skin infections. Methicillin-resistant S. aureus (MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 µg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD.


Subject(s)
Bacterial Toxins/genetics , Dermatitis, Atopic/microbiology , Exotoxins/genetics , Leukocidins/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Nasal Cavity/microbiology , Skin/microbiology , Adolescent , Child , Cross-Sectional Studies , DNA, Bacterial , Electrophoresis, Gel, Pulsed-Field , Female , Humans , Male , Microbial Sensitivity Tests , Multilocus Sequence Typing , Polymerase Chain Reaction , Reference Values , Severity of Illness Index , Staphylococcal Skin Infections/microbiology
6.
Lett Appl Microbiol ; 59(3): 342-7, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24909065

ABSTRACT

UNLABELLED: This study determined the changes of calcium concentration in a medium containing teeth/biofilm exposed to Coffea canephora extract (CCE). Enamel fragments were randomly fixed into two 24-well polystyrene plates containing BHI. Pooled human saliva was added to form biofilm on fragments. Specimens were divided into treatment groups (G, n = 8 per group) and treated with 50 µl daily for 1 min per week, as follows: G1, 20% CCE; G2, Milli-Q water (negative control); G3, antibiotic (positive control). Six fragments represented the blank control (G4). The calcium content was observed at baseline, 4 and 7 days of treatment by atomic-absorption spectrophotometry. Cross-sectional hardness of enamel was a demineralization indicator. Calcium increased in the medium after 4 and 7 days of treatment in G1 (3·80 ± 1·3 mg l(-1) and 4·93 ± 2·1 mg l(-1) , respectively) and G3 (4th day = 5·7 ± 1·8 mg l(-1) ; 7th day = 6·7 ± 3·5 mg l(-1) ) (P > 0·05). Calcium from G2 decreased after 7 days, which was different from G3 (P < 0·05). The lower calcium content, at the end of the experiment, was represented by G4, 2·16 ± 0·2 mg l(-1) . The increase in calcium after treatment with CCE is probably due to its antibacterial effect, which caused the bacterial lysis and consequent release of calcium in the medium. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed an inhibitory action of Coffea canephora against dental biofilm. This coffee species caused bacterial lysis and consequent release of calcium into the medium. Furthermore, the advantage of coffee as an antibacterial beverage is that it is consumed in a concentrated form (6-10%) as opposed to various medicinal infusions that have shown such effect in vitro and are usually consumed at 1-2%. Therefore, a light roasted C. canephora aqueous extract can be considered as a potential anticariogenic substance.


Subject(s)
Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Calcium/metabolism , Coffea/chemistry , Dental Enamel/drug effects , Plant Extracts/pharmacology , Culture Media, Conditioned , Dental Enamel/metabolism , Hardness , Humans , Tissue Culture Techniques , Tooth Demineralization/microbiology , Tooth Demineralization/prevention & control
7.
Infection ; 42(5): 835-42, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24934541

ABSTRACT

INTRODUCTION: Despite the recent advances in diagnosis and treatment, mortality rates due to infective endocarditis (IE) remain high if not aggressively treated with antibiotics, whether or not associated with surgery. Data on the prevalence, epidemiology and etiology of IE from developing countries remain scarce. The aim of this observational, prospective cohort study was to report a 5-year experience of IE at two teaching hospitals in Rio de Janeiro, Brazil. MATERIAL AND METHODS: Demographical, anamnestic and microbiological characteristics of 71 IE patients were evaluated during the period of January 2009 to March 2013. RESULTS: The mean age of the IE patients was 49.8 ± 2.4 years, of which 41 (57.7%) were males. The median time between the onset of symptoms and diagnosis of IE was 35.8 ± 4.8 days. A total of 31 (43.6%) cases of community-acquired infective endocarditis (CAIE) and 40 (56.3%) cases of healthcare-acquired infective endocarditis (HAIE) were observed. Staphylococcus aureus (30%) was the predominant cause of IE. Streptococcus spp. (45.1 %) was the predominant cause of the CAIE while S. aureus (32.5%) and Enterococcus spp. (27.2 %) were the main etiological agents of HAIE. For 64 (90.1 %) patients with native valve endocarditis, the mitral valve was the most commonly affected (48.3%). The main source of IE in this cohort was intravascular catheter. The tricuspid valve and renal chronic insufficiency were more frequent in patients with HAIE than CAIE (p = 0.001). The risk factors associated with in-hospital mortality rate (46.4%) in IE patients were: age over 45 (OR 3.4; 95% CI 1.03-11.24; p = 0.04) and chronic renal insufficiency (OR 38.3; 95% CI 3.2-449.4; p = 0.004). CONCLUSIONS: At two main teaching hospitals in Brazil, Streptococcus spp. was the principal pathogen of CAIE while S. aureus and Enterococcus spp. were the most frequent causes of HAIE. IE remains a serious disease associated with high in-hospital mortality rate (46.6%); especially, in individuals over 45 years of age and with renal failure. Data suggest that early surgery may improve the outcome of IE patients.


Subject(s)
Bacteria/isolation & purification , Bacterial Infections/mortality , Endocarditis/mortality , Hospital Mortality , Adult , Bacterial Infections/microbiology , Brazil/epidemiology , Community-Acquired Infections/microbiology , Community-Acquired Infections/mortality , Cross Infection/microbiology , Cross Infection/mortality , Endocarditis/microbiology , Female , Hospitals, Teaching/statistics & numerical data , Humans , Male , Middle Aged , Prospective Studies , Risk Factors
8.
J Appl Microbiol ; 116(6): 1418-26, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24524649

ABSTRACT

AIM: To evaluate the synergistic activity of antimicrobial drugs against lineages of methicillin-resistant Staphylococcus aureus (MRSA) carrying SCCmec IV. The biofilm production and related genes were also detected. METHODS AND RESULTS: Forty two MRSA isolates were tested for biofilm production and related genes. Biofilm/biomass susceptibility to gentamicin (G), linezolid (L), rifampicin (R) and vancomycin (V) was determined for six isolates from three lineages prevalent in Rio de Janeiro hospitals in concentrations ranging from 0·25 to 64 µg ml(-1). Biomass was evaluated by microtitre plate test and number of viable cells (CFU cm(-2)) and inspected by epifluorescence microscopy. All isolates presented the icaA and sasG genes, but only 38% were biofilm producers. There were 50 and 45% biomass reductions when concentrations ≥4 µg ml(-1) of R or L and ≥16 µg ml(-1) of G or V, respectively, were used. Synergism tests produced a 55% biomass reduction with R(2µgml-1) + G(16µgml-1), R(2µgml-1) + L(2µgml-1), R(2µgml-1) + V(4µgml-1), and L(2µgml-1) + V(4µgml-1). Number of viable cells was reduced from 2 to 3 logs with R(2µgml-1) + L(2µgml-1) and R(2µgml-1) + V(4µgml-1). CONCLUSIONS: Synergisms involving R plus L and R plus V caused important reductions in biofilm/biomass and the number of viable cells. Drug combinations should be considered in the chemotherapies of MRSA-SCCmec IV infections. SIGNIFICANCE AND IMPACT OF THE STUDY: Biofilms in MRSA infections restrict the clinical choice of antimicrobials. Thus, knowledge of the best options for monotherapy and drug synergisms could improve clinical results.


Subject(s)
Anti-Bacterial Agents/pharmacology , Methicillin-Resistant Staphylococcus aureus/drug effects , Acetamides/pharmacology , Biofilms/drug effects , Biomass , Drug Synergism , Gentamicins/pharmacology , Humans , Linezolid , Methicillin-Resistant Staphylococcus aureus/genetics , Microbial Sensitivity Tests , Microbial Viability , Oxazolidinones/pharmacology , Rifampin/pharmacology , Vancomycin/pharmacology
9.
J Hosp Infect ; 86(2): 151-4, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24433925

ABSTRACT

This study aimed to characterize meticillin-resistant Staphylococcus aureus (MRSA) lineages circulating in a Brazilian teaching hospital. MRSA isolates from nasal swabs were evaluated to assess antimicrobial susceptibility, staphylococcal cassette chromosome mec (SCCmec), Panton-Valentine leucocidin status, pulsed-field gel electrophoresis profile and multi-locus sequence type (MLST) analysis. Eighty-three MRSA isolates were analysed. SCCmec III (43.4%) and IV (49.4%) were predominant. ST1-IV (USA400) was more common in internal medicine (P = 0.002) whereas 'clone M' (SCCmec III) was more common in the medical and surgical intensive care unit (P = 0.004), and all isolates were ST5-IV (USA800) in dermatology (P < 0.001). These data improved the understanding of the MRSA epidemiology inside the hospital and helped to establish effective control measures.


Subject(s)
Carrier State/epidemiology , Cross Infection/epidemiology , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Staphylococcal Infections/epidemiology , Brazil/epidemiology , Carrier State/microbiology , Cross Infection/microbiology , Genes, Bacterial , Genotype , Hospitals, Teaching , Humans , Microbial Sensitivity Tests , Molecular Epidemiology , Molecular Typing , Nasal Mucosa/microbiology , Staphylococcal Infections/microbiology , Virulence Factors/genetics
10.
Eur J Clin Microbiol Infect Dis ; 33(1): 29-33, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23887612

ABSTRACT

The purpose of this study was to determine the reliability of the MicroScan WalkAway PosCombo21 (PC21) system for the identification of coagulase-negative staphylococci (CNS) strains and the detection of oxacillin resistance. Using molecular and phenotypic methods, 196 clinical strains were evaluated. The automated system demonstrated 100 % reliability for the identification of the clinical strains Staphylococcus haemolyticus, Staphylococcus hominis and Staphylococcus cohnii; 98.03 % reliability for the identification of Staphylococcus epidermidis; 70 % reliability for the identification of Staphylococcus lugdunensis; 40 % reliability for the identification of Staphylococcus warneri; and 28.57 % reliability for the identification of Staphylococcus capitis, but no reliability for the identification of Staphylococcus auricularis, Staphylococcus simulans and Staphylococcus xylosus. We concluded that the automated system provides accurate results for the more common CNS species but often fails to accurately identify less prevalent species. For the detection of oxacillin resistance, the automated system showed 100 % specificity and 90.22 % sensitivity. Thus, the PC21 panel detects oxacillin-resistant strains, but is limited by the heteroresistance that is observed when using most phenotypic methods.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteriological Techniques/methods , Coagulase/metabolism , Oxacillin/pharmacology , Staphylococcal Infections/diagnosis , Staphylococcus/isolation & purification , beta-Lactam Resistance , Humans , Sensitivity and Specificity , Staphylococcal Infections/microbiology , Staphylococcus/drug effects , Staphylococcus/enzymology
11.
Spec Care Dentist ; 33(6): 301-3, 2013.
Article in English | MEDLINE | ID: mdl-24164229

ABSTRACT

The purpose of this study was to describe an unusual case of a lingual schwannoma associated with a mixed connective tissue disease (MCTD). A case report. A lingual schwannoma with loss of lingual sensitivity and slightly increased size in an 18-year-old patient with MCTD was correctly diagnosed through a biopsy and no reoccurrence was observed one year after the surgical removal of the tumor and sensitivity returned 3 months after surgery. This case was considered uncommon, making the clinical diagnosis challenging in view of the diversity of possibilities for its differential diagnosis, thus showing the importance of a biopsy to confirm the diagnosis and long term follow up in such cases.


Subject(s)
Conjunctival Diseases/physiopathology , Neurilemmoma/physiopathology , Tongue/physiopathology , Adolescent , Conjunctival Diseases/complications , Female , Humans , Neurilemmoma/complications
12.
J Med Microbiol ; 62(Pt 5): 754-760, 2013 May.
Article in English | MEDLINE | ID: mdl-23449875

ABSTRACT

Subinhibitory concentrations (subMICs) of antibiotics may alter bacterial surface properties and change microbial physiology. This study aimed to investigate the effect of a subMIC (⅛ MIC) of penicillin (PEN) and erythromycin (ERY) on bacterial morphology, haemagglutinating activity, cell-surface hydrophobicity (CSH) and biofilm formation on glass and polystyrene surfaces, as well as the distribution of cell-surface acidic anionic residues of Corynebacterium diphtheriae strains (HC01 tox(-) strain; CDC-E8392 and 241 tox(+) strains). All micro-organisms tested were susceptible to PEN and ERY. Growth in the presence of PEN induced bacterial filamentation, whereas subMIC of ERY caused cell-size reduction of strains 241 and CDC-E8392. Adherence to human erythrocytes was reduced after growth in the presence of ERY, while CSH was increased by a subMIC of both antibiotics in bacterial adherence to n-hexadecane assays. Conversely, antibiotic inhibition of biofilm formation was not observed. All strains enhanced biofilm formation on glass after treatment with ERY, while only strain 241 increased glass adherence after cultivation in the presence of PEN. Biofilm production on polystyrene surfaces was improved by ⅛ MIC of ERY. After growth in the presence of both antimicrobial agents, strains 241 and CDC-E8392 exhibited anionic surface charges with focal distribution. In conclusion, subMICs of PEN and ERY modified bacterial surface properties and enhanced not only biofilm formation but also cell-surface hydrophobicity. Antibiotic-induced biofilm formation may contribute to the inconsistent success of antimicrobial therapy for C. diphtheriae infections.


Subject(s)
Anti-Bacterial Agents/pharmacology , Biofilms/growth & development , Corynebacterium diphtheriae/drug effects , Erythromycin/pharmacology , Penicillins/pharmacology , Animals , Biofilms/drug effects , Corynebacterium diphtheriae/physiology , Corynebacterium diphtheriae/ultrastructure , Drug Resistance, Bacterial , Glass , Hydrophobic and Hydrophilic Interactions , Microbial Sensitivity Tests , Microscopy, Electron, Transmission , Polystyrenes , Surface Properties
13.
Infection ; 41(4): 851-4, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23456477

ABSTRACT

Staphylococcus aureus is the main causal pathogen of infective endocarditis (IE), which may have distinct origins, namely, community, nosocomial, or non-nosocomial healthcare-associated (NNHCA). We report the first case of NNHCA-IE caused by methicillin-resistant S. aureus strain USA400/SCCmec IV in which the combination therapy of rifampin and vancomycin had a favorable outcome for the patient.


Subject(s)
Endocarditis/diagnosis , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Staphylococcal Infections/diagnosis , Adult , Anti-Bacterial Agents/administration & dosage , Brazil , Echocardiography, Transesophageal , Endocarditis/drug therapy , Endocarditis/microbiology , Endocarditis/pathology , Genotype , Health Facilities , Humans , Male , Molecular Typing , Rifampin/administration & dosage , Staphylococcal Infections/drug therapy , Staphylococcal Infections/microbiology , Staphylococcal Infections/pathology , Treatment Outcome , Vancomycin/administration & dosage
14.
J Clin Microbiol ; 50(1): 166-8, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21976766

ABSTRACT

Phenotypic and molecular methods were used to characterize the antibiotic resistance of 64 clinical isolates of Staphylococcus haemolyticus. By PCR of the mecA gene, 87% were found to be methicillin resistant. Approximately 55% harbored staphylococcal cassette chromosome mec element (SCCmec) type V, and only one SCCmec type IV. Many isolates (75%) displayed multiresistance, and pulsotype analysis showed a high diversity.


Subject(s)
Cross Infection/epidemiology , Cross Infection/microbiology , Methicillin Resistance , Staphylococcal Infections/epidemiology , Staphylococcal Infections/microbiology , Staphylococcus haemolyticus/isolation & purification , Anti-Bacterial Agents/pharmacology , Cluster Analysis , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Female , Genes, Bacterial , Genotype , Humans , Male , Microbial Sensitivity Tests , Molecular Typing , Polymerase Chain Reaction , Staphylococcus haemolyticus/drug effects , Staphylococcus haemolyticus/genetics
15.
Arch Oral Biol ; 56(6): 556-64, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21185010

ABSTRACT

OBJECTIVES: The antibacterial activity of Coffea canephora extract was evaluated in vitro against Streptococcus mutans and Streptococcus sobrinus. The viability of planktonic cells was analysed by susceptibility tests (MIC and MBC) and time-kill assays. The effect of the extract on dental demineralisation was also investigated. METHODS: Primary 1st molar fragments (n=24) were inoculated with a saliva pool and sustained in a multiple plaque growth system for 10 days to form biofilm. The biofilm was treated with light roasted C. canephora extract at 20%, Milli-Q water (negative control) and chlorhexidine (positive control) once a day, during a week. Blank controls comprised fragments without treatment. Biofilm pH was monitored in the last day of treatment. Changes in tooth mineralisation were assessed by cross-sectional microhardness (CSMH) test. RESULTS: MIC and MBC for S. mutans were 7±2 mg/mL and 160±0 mg/mL, respectively, showing no activity for S. sobrinus. The extract produced a 4-log reduction in the number of colonies of S. mutans after 3-h treatment (p<0.05) with undiluted extract (20%) and MBC concentration (16%). There was no difference among negative/blank controls and coffee plaque pH. Differences between CSMH values of dental fragments subjected to the coffee extract and to chlorhexidine were not significant. At depths up to 30 µm from the enamel surface, coffee extract and chlorhexidine promoted higher CSMH values when compared to blank/negative controls (p<0.05). CONCLUSION: Our data suggest that light roasted C. canephora extract is beneficial as an anticariogenic substance.


Subject(s)
Coffea , Plant Extracts/pharmacology , Streptococcus mutans/drug effects , Streptococcus sobrinus/drug effects , Tooth Demineralization/prevention & control , Tooth, Deciduous/drug effects , Adult , Analysis of Variance , Biofilms/drug effects , Coffea/chemistry , Dental Plaque/microbiology , Female , Hardness , Humans , Hydrogen-Ion Concentration , Male , Microbial Sensitivity Tests , Microbial Viability/drug effects , Statistics, Nonparametric , Streptococcus mutans/growth & development , Streptococcus sobrinus/growth & development
16.
Br Dent J ; 209(12): E19, 2010 Dec 18.
Article in English | MEDLINE | ID: mdl-20885412

ABSTRACT

AIMS: To assess the effect of combining 1% chlorhexidine varnish (CHX) with xylitol chewing gum (XYL) on Streptococcus mutans and biofilm levels in 6-8-year-old children. DESIGN: Randomised controlled study. SUBJECTS AND METHODS: Eighty-two 6-8-year-old children were randomly divided into groups as follows: G1 (n = 20): xylitol chewing gum twice a day after breakfast and lunch; G2 (n = 20): xylitol gum as G1 plus chlorhexidine varnish application at the start of the study and after one and two months; G3 (n = 20): chlorhexidine varnish as G2; and G4 (n = 22): fluoride gel application at the start of the study and after one and two months. Microbiological tests were performed to assess Streptococcus mutans colony forming units (CFU) and the teeth of those children with moderate or higher CFU scores were examined for visible biofilm. CFU scores were categorised as follows: 0 = absence of S. mutans, 1 = low level (1-10 CFU), 2 = moderate level (11-100 CFU), 3 = high level (101-250 CFU), 4 = very high level (>250 CFU). Biofilm scores based on a scale from 0 (absence of biofilm) to 5 (thick biofilm firmly adhered to posterior and anterior teeth) were obtained. RESULTS: The biofilm reduction was greater in G2 and G3, with mean values of 3.38 and 3.17 to 1.79 and 1.88, respectively (p <0.05). All groups presented a reduction in the S. mutans levels. XYL + CHX showed the largest reduction throughout the study period, with 58.3% in the first month, 84.2% in the second and 92.9% at the end of the study. CONCLUSIONS: The XYL + CHX combination was efficient and superior to single treatments in controlling biofilm and suppressing S. mutans.


Subject(s)
Anti-Infective Agents, Local/therapeutic use , Biofilms/drug effects , Cariostatic Agents/therapeutic use , Chewing Gum , Chlorhexidine/therapeutic use , Streptococcus mutans/drug effects , Sweetening Agents/therapeutic use , Xylitol/therapeutic use , Acidulated Phosphate Fluoride/therapeutic use , Anti-Infective Agents, Local/administration & dosage , Bacterial Load , Child , Chlorhexidine/administration & dosage , Dental Plaque/microbiology , Drug Combinations , Female , Fluorides, Topical/therapeutic use , Follow-Up Studies , Gels , Humans , Male , Saliva/microbiology , Thymol/administration & dosage , Thymol/therapeutic use , Tooth/microbiology
17.
Res Vet Sci ; 88(2): 214-7, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19765787

ABSTRACT

To compare the genotypes of Campylobacter jejuni and Campylobacter coli isolates of human and animal origin collected in Rio de Janeiro City, 30 C. jejuni and 35 C. coli isolates from animal sources (n=45) and human patients with gastroenteritis (n=20) were genotyped by PCR-based techniques, namely random amplified polymorphic DNA (RAPD-PCR) and enterobacterial repetitive intergenic consensus sequence (ERIC-PCR). RAPD-PCR identified 50 types and ERIC-PCR identified 22 genotypes, among the 65 Campylobacter isolates. Both PCR methods discriminated the C. jejuni and C. coli groups of isolates. Combining the results of both methods, no single genotype was shared between isolates from human and animal sources. Two groups of two C. coli isolates each with identical genotypes were found among poultry and pig isolates. A high level of genetic diversity observed among the Campylobacter isolates suggests lack of overlap between isolates from different sources.


Subject(s)
Campylobacter Infections/microbiology , Campylobacter coli/genetics , Campylobacter jejuni/genetics , Genetic Variation , Genotype , Animals , Brazil/epidemiology , Campylobacter Infections/epidemiology , Gastroenteritis/veterinary , Humans , Phylogeny
18.
J Endod ; 32(8): 722-6, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16861069

ABSTRACT

Enterococcus faecalis is the most commonly found species in root-filled teeth evincing recalcitrant periradicular lesions and as a consequence, a role in causation of endodontic treatment failure has been suggested. The purpose of this study was to evaluate the prevalence of this bacterial species in root-filled teeth with or without periradicular lesions. Identification of E. faecalis was carried out by polymerase chain reaction (PCR) or conventional culture procedures. Overall, E. faecalis was detected by species-specific 16S rRNA gene-based PCR in 40/50 teeth (80%), while culture revealed the occurrence of this species in 8/50 teeth (16%). PCR was significantly more effective than culture in detecting this bacterial species (p < 0.001). Of 27 root-filled teeth with no periradicular lesions, E. faecalis was found in 22 cases (81.5%) by PCR and in five cases (18.5%) by culture. Of 23 root-filled teeth with periradicular lesions, E. faecalis was identified in 18 cases (78%) by PCR and in three cases (13%) by culture. Regardless of the identification technique used, no significant difference was observed when comparing the occurrence of E. faecalis in root-filled teeth with and without periradicular lesions (p > 0.05). Although these findings apparently put into question the status of E. faecalis as the main species causing endodontic treatment failure, other related factors still need to be clarified before this assumption turns into certainty.


Subject(s)
Enterococcus faecalis/isolation & purification , Periapical Diseases/microbiology , Tooth, Nonvital/microbiology , Adult , Aged , Animals , Cell Culture Techniques , Chi-Square Distribution , Female , Humans , Male , Middle Aged , Periapical Diseases/diagnostic imaging , Polymerase Chain Reaction , Radiography , Sheep , Treatment Failure
19.
J Chemother ; 18(2): 151-6, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16736883

ABSTRACT

The present study was designed to characterize beta-lactamase genes and evaluate polymerase chain reaction (PCR) typing for multidrug-resistant Pseudomonas aeruginosa pulsed-field gel electrophoresis (PFGE) genotype A isolates from Rio de Janeiro, Brazil, collected between April 1999 and March 2000 and one additional isolate collected in June 2002. As reported previously, all of the genotype A isolates produced non-characterized metallo-beta-lactamase. These isolates (22) were screened for the bla(SPM) gene by PCR and dot-blotting. Isolates were typed by PCR fingerprinting with primers RAPD-1, 272, 208, 1290, ERIC-1 and ERIC-2. The bla(SPM) gene was detected in 18 (82%) of the 22 isolates. PCR fingerprinting gave results that correlated with PFGE, except with primer 1290. In Rio de Janeiro and other Brazilian states, nearly all SPM-producing P. aeruginosa isolates belong to a single PFGE type accounting for a large proportion of drug-resistant P. aeruginosa hospital infections. RAPD PCR fingerprinting may be a useful technique to screen for an epidemic multidrug-resistant strain in Brazil.


Subject(s)
Anti-Bacterial Agents/adverse effects , Disease Outbreaks , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , beta-Lactamases/genetics , Brazil/epidemiology , DNA, Bacterial/genetics , DNA, Bacterial/isolation & purification , Drug Resistance, Microbial , Electrophoresis, Gel, Pulsed-Field , Humans , Polymerase Chain Reaction , Pseudomonas Infections/drug therapy , Pseudomonas Infections/epidemiology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/enzymology , beta-Lactam Resistance , beta-Lactamases/isolation & purification
20.
Lett Appl Microbiol ; 42(3): 215-21, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16478507

ABSTRACT

AIMS: To investigate the activity of seven staphylococcins, bacteriocins produced by staphylococci, against multiresistant Staphylococcus aureus and coagulase-negative staphylococci (CNS) involved in human infections. METHODS AND RESULTS: Four bacteriocins produced by Staph. epidermidis (Pep5, epidermin, epilancin K7 and epicidin 280) and three produced by Staph. aureus (aureocins A70, A53 and 215FN) were tested. Sixteen Staph. aureus strains, including a representative strain of the endemic Brazilian methicillin-resistant clone (MRSA), and 57 CNS strains were used as indicators. Among the staphylococcins used, Pep5 was able to inhibit 77.2% of the CNS strains and 87.5% of the Staph. aureus strains tested, including the Brazilian MRSA endemic clone, responsible for a large number of hospital-acquired infections in Brazil. On the other hand, aureocin A53 and epidermin presented a high antagonistic activity only against the Staph. aureus strains, being able to inhibit, respectively, 87.5% and 81.3% of them, including also the Brazilian MRSA endemic clone. The remaining bacteriocins inhibited only a low percentage of the nosocomial staphylococcal strains tested. CONCLUSIONS: Aureocin A53 and epidermin have potential applications against MRSA, whereas Pep5 seems to be an attractive agent against both MRSA and CNS, including mupirocin-resistant strains and the Brazilian endemic clone of MRSA, which is also found disseminated in other countries. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteriocins may represent alternative agents to control important nosocomial pathogens.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteriocins/pharmacology , Staphylococcus aureus/drug effects , Anti-Bacterial Agents/metabolism , Bacteriocins/metabolism , Brazil , Coagulase/metabolism , Humans , Methicillin Resistance/drug effects , Microbial Sensitivity Tests , Staphylococcal Infections/microbiology , Staphylococcus aureus/enzymology , Staphylococcus aureus/metabolism , Staphylococcus epidermidis/metabolism
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