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1.
Biosci. j. (Online) ; 39: e39029, 2023. ilus, graf, tab
Artigo em Inglês | LILACS | ID: biblio-1425193

RESUMO

Rifampicin has broad-spectrum antimicrobial activity, but it can cause nephrotoxic and hepatotoxic damage because high doses are required. Nanosystems emerge as a perspective to improve the transport systems of this drug. In this work, iron oxide nanoparticles were synthesised, functionalized with lauric acid, and rifampicin was incorporated into the nanosystem. The samples were characterized by spectroscopic techniques: electronics in the visible ultraviolet region (UV-vis), vibrational absorption in the infrared region (IR), X-ray diffractometry (XRD), and dynamic light scattering (DSL). The toxicity of the nanocompounds and the antimicrobial activity against Staphylococcus aureus ATCC 25923 were studied by the Artemia salina lethality and disc diffusion techniques, respectively. As a result, IR analysis showed characteristic vibrations of laurate and rifampicin on the surface of the nanosystem. The presence of magnetic iron oxide was confirmed by XRD and the mean diameter of the crystallites was 8.37 nm. The hydrodynamic diameter of rifampicin associated with the nanosystem was 402 nm and that of the nanosystem without rifampicin was 57 nm. The compounds did not show toxicity to Artemia salina and the in vitro antimicrobial activity against Staphylococcus aureus was slightly decreased when rifampicin was associated with the nanosystem. In general terms, the results showed that iron oxide nanoparticles showed no toxicity and reduced the toxicity of rifampicin by 41.54% when carried compared to free rifampicin. Therefore, magnetic iron oxide nanoparticles may have the potential to act as a platform for associated drugs.


Assuntos
Rifampina , Staphylococcus aureus , Nanopartículas Magnéticas de Óxido de Ferro , Anti-Infecciosos
2.
Microorganisms ; 10(12)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36557737

RESUMO

Medical-device-related infections are considered a worldwide public health problem. In particular, urinary catheters are responsible for 75% of cases of hospital urinary infections (a mortality rate of 2.3%) and present a high cost for public and private health systems. Some actions have been performed and described aiming to avoid it, including clinical guidelines for catheterization procedure, antibiotic prophylaxis, and use of antimicrobial coated-urinary catheters. In this review paper, we present and discuss the functionalization of urinary catheters surfaces with antimicrobial entities (e.g., photosensitizers, antibiotics, polymers, silver salts, oxides, bacteriophage, and enzymes) highlighting the immobilization of photosensitizing molecules for antimicrobial photodynamic applications. Moreover, the characterization techniques and (photo)antimicrobial effects of the coated-urinary catheters are described and discussed. We highlight the most significant examples in the last decade (2011-2021) concerning the antimicrobial coated-urinary catheter and their potential use, limitations, and future perspectives.

3.
Biol Trace Elem Res ; 198(2): 669-680, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32266641

RESUMO

Ruthenium(II)/benzonitrile complexes have demonstrated promising anticancer properties. Considering that there are no specific therapies for treating sarcoma, we decided to evaluate the cytotoxic, genotoxic, and lethal effects of cis-[RuCl(BzCN)(phen)(dppb)]PF6 (BzCN = benzonitrile; phen = 1,10-phenanthroline; dppb = 1,4-bis-(diphenylphosphino)butane), as well as the mechanism of cell death induction that occurs against murine sarcoma-180 tumor. Thus, MTT assay was applied to assess the ruthenium cytotoxicity, showing that the compound is a more potent inhibitor for the sarcoma-180 tumor cell viability than normal cells (lymphocytes). The comet assay indicated low genotoxic for normal cells. cis-[RuCl(BzCN)(phen)(dppb)]PF6 also showed moderate lethality in Artemia salina. The complex induced cell cycle arrest in the G0/G1 phase in sarcoma-180 cells. In addition, the complex caused S180 cells to die by apoptosis by an increase in Annexin-V-positive cells and morphological changes typical of apoptotic cells. Additionally, cis-[RuCl(BzCN)(phen)(dppb)]PF6 increased the gene expression of Bax, Casp3, and Tp53 in S180 cells. By using a western blot, we observed an increased protein level of TNF-R2, Bax, and p21. In conclusion, cis-[RuCl(BzCN)(phen)(dppb)]PF6 is active and selective for sarcoma-180 cells, leading to cell cycle arrest at the G0/G1 and cell death through a caspases-mediated and Tp53/p21-mediated pathway.


Assuntos
Antineoplásicos , Complexos de Coordenação , Rutênio , Sarcoma , Animais , Antineoplásicos/farmacologia , Apoptose , Artemia , Caspases , Linhagem Celular Tumoral , Complexos de Coordenação/farmacologia , Inibidor de Quinase Dependente de Ciclina p21 , Camundongos , Nitrilas , Rutênio/farmacologia , Sarcoma/tratamento farmacológico , Proteína Supressora de Tumor p53
4.
AAPS PharmSciTech ; 20(5): 191, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31111300

RESUMO

Hard capsules are made from gelatin, an organic polymer obtained through the hydrolysis of collagen present in animal tissues. Gelatin can be degraded by microorganisms and some strategies can be used to control contaminating micro-organisms. Gamma irradiation is considered as an effective sterilization method; however, its application can alter the chemical structure of the irradiated product. Samples of hard gelatin capsules were irradiated at doses of 5, 15, and 25 kGy at room temperature. The characterizations of the physical and chemical effects were evaluated by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffractometry, and differential scanning calorimetry techniques. Furthermore, hard gelatin capsule samples were dissolved and inoculated with Bacillus subtilis, a Gram-positive spore-forming bacterium, to evaluate the effect of gamma ray radiation on bacterial counts. The results showed that gamma radiation did not interfere on physical parameters of the capsule, such as moisture content, mass, body and cap length, and disintegration time. Nevertheless, differential scanning calorimetry results demonstrated changes in the glass transition temperature, indicating the formation of crosslinking in irradiated capsules. It was observed that there were significant reductions on the inoculated bacterial population starting from the lowest irradiation dose and there was no detection of bacterial growth from the 15 kGy dose, while in the non-irradiated samples were found with 104 CFU mL-1 of bacteria. Therefore, this work concludes that the gamma radiation is effective on the reduction of the microbial population, cause discrete physical-chemical alterations, and could be used as a hard capsule sterilization technique.


Assuntos
Cápsulas/efeitos da radiação , Raios gama , Gelatina/efeitos da radiação , Esterilização/métodos , Varredura Diferencial de Calorimetria , Cápsulas/química , Gelatina/química
5.
Int J Biol Macromol ; 105(Pt 1): 385-392, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28756196

RESUMO

Investigation of the antimicrobial action of carboxymethyl chitosan (CMCh) is among the alternative approaches in the control of pathogenic microorganisms. This study aimed to screen the toxicity using the brine shrimp lethality assay and to investigate the inhibitory activity of carboxymethyl in isolation or in combination with silver nitrate, copper sulfate and zinc sulfate on biofilm formation by Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Kocuria rhizophila ATCC 9341, Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 25312, and Burkholderia cepacia ATCC 17759. The CMCh was obtained by reacting chitosan with monochloroacetic acid under alkaline conditions, and the occurrence of carboxymethylation was evidenced by FTIR and 1H NMR spectroscopy. The CMCh was combined with metallic salts (AgNO3, CuSO4·5H2O and ZnSO4) to perform the bioassays to screen the toxicity, to determine the minimum inhibitory concentration and the impact of sub-inhibitory concentrations against biofilm formation. Although CMCh did not show inhibitory activity against bacterial growth, it had an interesting level of inhibition of bacterial biofilm. The results suggest that sub-inhibitory concentrations of compounds were effective against biofilm formation.


Assuntos
Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Quitosana/análogos & derivados , Metais Pesados/química , Animais , Artemia , Biofilmes/crescimento & desenvolvimento , Quitosana/química , Quitosana/farmacologia , Quitosana/toxicidade , Cobre/química , Testes de Sensibilidade Microbiana , Prata/química , Sulfatos/química , Zinco/química
6.
Biosci. j. (Online) ; 33(3): 739-746, may/jun. 2017. tab
Artigo em Inglês | LILACS | ID: biblio-966233

RESUMO

Cell surface adhesion is considered an essential step in the spread, infection and persistence of Candida yeasts in the host. Their ability to adhere on biotic and abiotic surfaces depends on several factors, including hydrophobicity. Once attached, these yeasts are capable of growing in biofilms, which are constituted of structured communities of encapsulated cells within an extracellular matrix, resistant to antifungal agents. In this context, this study aimed to analyze the cell surface hydrophobicity and specific biofilm formation of six Candida strains in different culture media: Sabouraud dextrose broth (SDB), artificial saliva (AS), Roswell Park Memorial Institute medium (RPMI 1640) and N-acetylglucosamine-yeast nitrogen base proline (NYP). Six yeasts of the genus Candida were studied: three C. albicans (Ca): Ca ATCC 10231 and the clinical isolates Ca34 and Ca05 and C. parapsilosis (Cp): Cp ATCC 22019 and the clinical isolates Cp120 and Cp38. Hydrophobicity was calculated as the percentage reduction in turbidity of the aqueous phase, due to the retention of the hydrophobic cells in hydrocarbon by the hydrocarbon-water biphasic assay following the MATH (Microbial Adhesion to Hydrocarbon) method. The biofilm formation index was calculated as the optical density obtained by the growth of the yeasts in the culture media in a polystyrene microtiter plate, subsequently stained with 1% violet crystal. The results showed that hydrophobicity varied according to the media and the yeasts studied, and two of these (Ca34 and Ca10231) presented significant variation between the media. A more hydrophobic character was observed in yeasts grown on RPMI-1640 medium, and those grown on Sabouraud dextrose broth appeared more hydrophilic. The specific biofilm formation index was more intense for RPMI 1640 than in other media, which was expected, due to its ability to induce the transition between yeast-hyphae morphology, which is one of the key factors involved in the adhesion of C. albicans on different surfaces. RPMI 1640 was the best medium for obtaining biofilm in vitro, due to its greater hydrophobicity, which can enhance cell adhesion to the polystyrene plate, and due to its nutrient content, necessary for complete cell growth and biofilm formation.


A adesão é considerada um passo essencial para a disseminação, infecção e persistência das leveduras do gênero Candida nos hospedeiros. A habilidade dessas leveduras em se aderir a superfícies bióticas e abióticas depende de fatores, incluindo a hidrofobicidade da superfície celular. Uma vez aderidas, estas leveduras são capazes de crescer como biofilmes, os quais são caracterizados como comunidades estruturadas de células encapsuladas dentro de uma matriz extracelular, resistentes a drogas antifúngicas. Neste contexto, objetivou-se analisar a hidrofobicidade da superfície celular e a formação específica de biofilme de Candida spp. em diferentes meios de cultura: caldo Sabouraud dextrose (CSD), saliva artificial (SA), Roswell Park Memorial Institute medium (RPMI 1640) e N-acetylglucosamineyeast nitrogen base-proline (NYP). Foram estudadas seis leveduras do gênero Candida, sendo três C. albicans (Ca): Ca ATCC 10231 e os isolados clínicos Ca34 e Ca05 e C. parapsilosis (Cp): Cp ATCC 22019 e os isolados clínicos Cp120 e Cp38. A hidrofobicidade foi calculada como a porcentagem da redução da turbidez da fase aquosa, devido a retenção das células hidrofóbicas no hidrocarboneto pelo método bifásico água-hidrocarboneto MATH (Teste de Adesão Microbiana a Hidrocarbonetos). O índice de formação de biofilme foi calculado com as densidades ópticas obtidas por meio do crescimento das leveduras nos meios de cultura em poços de placa de microtitulação de poliestireno e posteriormente corados com cristal violeta a 1%. Os resultados demonstraram que a hidrofobicidade variou de acordo com os meios e as leveduras estudadas, sendo que duas (Ca34 e Ca10231) apresentaram variação significativa entre os meios. Foi verificado um caráter mais hidrofóbico das células crescidas em RPMI 1640 e mais hidrofílico nas células crescidas em caldo Sabouraud dextrose. A formação específica de biofilme apresentou-se mais intensa em RPMI 1640 do que nos outros meios, o que já era esperado pela sua capacidade de induzir o processo de transição levedura-hifa, o qual é considerado um dos fatores cruciais envolvidos na adesão de leveduras. Com os resultados obtidos, infere-se que o RPMI 1640 é o melhor meio para obtenção de biofilme in vitro, pois as células foram mais hidrofóbicas, o que pode aumentar a adesão das


Assuntos
Candida albicans , Biofilmes , Interações Hidrofóbicas e Hidrofílicas , Candida parapsilosis
7.
Rev. colomb. ciencias quim. farm ; 44(2): 179-188, mayo-ago. 2015. ilus, graf, mapas, tab
Artigo em Português | LILACS | ID: lil-765584

RESUMO

O presente estudo teve como finalidade evidenciar o uso indiscriminado de diclofenaco de potássio e o desconhecimento dos efeitos colaterais deste medicamento contidos na bula pelos idosos do Município de Anápolis, Goiás em 2014. Trata-se de uma pesquisa analítica em loco que teve como amostra 2500 indivíduos idosos de 58-77 anos. Os dados foram compilados através de questionários e revelaram que a droga foi extensivamente utilizada pelos entrevistados sem receituário médico. Dentre os motivos que os levaram a adquirir o diclofenaco de potássio, ressaltam-se: o preço acessível e à eficácia da droga sobre sintomas como dores no corpo, principalmente nas pernas e costas. Foi detectado um estimulo a automedicação resultante do sistema de vendas praticado nas drogarias, nas quais atendentes sem conhecimento farmacológico pertinente realizam indicações de fármacos sem conhecimento técnico. Os resultados da pesquisa reforçam a necessidade de maiores orientações sobre o uso racional desse medicamento, uma vez que o consumo inadequado pode ocasionar distúrbios gástricos, renais e circulatórios.


This work intended to evaluate the drug abuse and the knowledge of side effects presented in the guidelines of potassium diclophenac used by elderly people from Anapolis-Brazil. In this study, 2500 people, ranging between 58 and 77 years old, were interviewed in 2014. The data collected by a questionnaire revealed the excessive use of this drug without medical prescription. The main reasons raised by the respondents, when asked about why they use this drug, were the affordable price and the efficiency of potassium diclophenac in the common symptoms at this age, especially back and joint pain. The market, with unprepared sellers, stimulates self-medication and input a risk at the health of Brazilian population. The results presented the need of further guidance on the rational use of this drug, since inadequate intake may cause stomach, kidney and circulatory disorders.

8.
Pediatr Res ; 69(1): 23-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20885335

RESUMO

Aimed to prevent Streptococcus pneumoniae biofilm infections, we studied the adherence of nine pneumococcal strains to polystyrene plates and on epithelial cells and the antiadhesive effect of albumin and xylitol. The adherence was variable among strains, but there was a good correlation between their adherent ability and binding to abiotic material and cells. Strains of serotypes 6B and 23F were the most adherent organisms, whereas serotype 3 strains were the least adherent. Human serum albumin (HSA) enhanced bacterial growth at low concentrations (0.5-2.5%) but inhibited it at 10%. Xylitol inhibited bacterial growth of all strains at concentrations ranging from 5 to 15%. Exposure to 0.5-5% HSA in solubilized form and to 5% HSA precoating of plates diminished adherence to polystyrene >80% for all strains, except for serotype 3 strains. Contrarily, 0.5 and 5% xylitol did not diminish significantly pneumococcal adherence to polystyrene plates or on epithelial cells. Our results suggest that 1) the potential application of HSA coatings on medical devices to inhibit pneumococcal adherence and 2) the possible beneficial effect of xylitol in preventing some pneumococcal infections could be because of its antimicrobial activity rather than to an antiadhesive effect.


Assuntos
Aderência Bacteriana/fisiologia , Biofilmes/crescimento & desenvolvimento , Células Epiteliais/fisiologia , Poliestirenos/química , Streptococcus pneumoniae/fisiologia , Aderência Bacteriana/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Células Epiteliais/química , Humanos , Albumina Sérica/farmacologia , Especificidade da Espécie , Streptococcus pneumoniae/química , Xilitol/farmacologia
9.
Diagn Microbiol Infect Dis ; 67(4): 311-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20638597

RESUMO

Streptococcus pneumoniae ability to produce biofilms may induce persistent infections and difficulties for eradication in vivo. We investigated the ability of 11 pneumococcal strains (serotypes 3, 6B, 9V, 19F, and 23F) to form biofilms on polystyrene plates at 16 and 24 h. The extent of biofilm was greater at 24 h in 10 strains, being the highest magnitude for serotype 3 strains. Human serum albumin at 25,000 microg/mL and ibuprofen at 128 microg/mL significantly reduced biofilm formation in 7 and 5 strains, respectively. Amoxicillin, erythromycin, and levofloxacin at supra-MIC concentrations were very active against planktonic cells of 3 selected strains but lower on biofilm-associated organisms in 2 strains and null against the third. Although N-acetyl-l-cysteine had very little activity against both planktonic and biofilm-forming organisms, when combined with the 3 antibiotics, a slightly enhanced activity against biofilm-embedded organisms in 1 strain and combined with amoxicillin in another one was observed.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Albumina Sérica/metabolismo , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/fisiologia , Acetilcisteína/farmacologia , Amoxicilina/farmacologia , Eritromicina/farmacologia , Humanos , Ibuprofeno/farmacologia , Levofloxacino , Ofloxacino/farmacologia , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/crescimento & desenvolvimento
10.
Int J Antimicrob Agents ; 35(6): 544-9, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20303716

RESUMO

Therapeutic alternatives are needed against infections caused by highly multidrug-resistant Streptococcus pneumoniae. Novobiocin, an old antibiotic, was tested in vitro and in a murine sepsis model against one amoxicillin-susceptible and three amoxicillin-resistant strains [minimum inhibitory concentrations (MICs) 8-64 mg/L]. Novobiocin MICs for all strains were 0.25-0.5 mg/L. In sepsis, novobiocin and amoxicillin were evaluated at 25, 50, 100 and 200 mg/kg given at 1, 5, 24 and 48 h post bacterial challenge. The most effective regimens in animals infected with the amoxicillin-susceptible strain were 200 mg/kg novobiocin and 25 mg/kg amoxicillin, achieving 100% survival and undetectable organisms in the peritoneum. Among mice infected with amoxicillin-resistant S. pneumoniae, 200 mg/kg novobiocin gave the highest protection (90-100% survivors), followed by 200mg/kg amoxicillin (60-100%), 100 mg/kg novobiocin (50-87.5%) and 50 mg/kg amoxicillin (14.3-25%). The killing effect of antibiotics in the peritoneum (mean Deltalog(10) colony-forming units/mL between treated and control mice) was as follows: 200 mg/kg novobiocin (-6.6)>200 mg/kg amoxicillin (-5.6)>100 mg/kg novobiocin (-3.7) > 50 mg/kg amoxicillin (-0.7). Total plasma and ultrafiltrate pharmacokinetics of novobiocin (200 mg/kg, single dose) in non-infected mice showed, respectively, half-lives of 151 min and 215 min, area under the concentration-time curves (AUCs) of 945.0 mgh/L and 136.6 mgh/L and maximal concentrations of 147 mg/L and 18 mg/L. Novobiocin may be a promising agent for therapy of highly beta-lactam-resistant pneumococcal infections.


Assuntos
Amoxicilina/uso terapêutico , Antibacterianos/uso terapêutico , Novobiocina/uso terapêutico , Infecções Pneumocócicas/tratamento farmacológico , Sepse/tratamento farmacológico , Streptococcus pneumoniae/efeitos dos fármacos , Amoxicilina/administração & dosagem , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Contagem de Colônia Microbiana , Farmacorresistência Bacteriana , Feminino , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Novobiocina/administração & dosagem , Novobiocina/farmacologia , Peritônio/microbiologia , Infecções Pneumocócicas/microbiologia , Sepse/microbiologia , Streptococcus pneumoniae/enzimologia , Análise de Sobrevida , Resultado do Tratamento , beta-Lactamas/farmacologia
11.
Diagn Microbiol Infect Dis ; 66(3): 336-8, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19939599

RESUMO

The in vitro activity of 22 antibiotics (including novobiocin) and beta-lactam/gentamicin combinations was assessed against 11 multidrug-resistant pneumococcal strains. Among orally administered drugs, only telithromycin, levofloxacin, and linezolid were active against all isolates, but their use is not indicated in pediatrics. Novobiocin could be a potential therapeutic alternative.


Assuntos
Antibacterianos/farmacologia , Penicilinas/farmacologia , Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana , Streptococcus pneumoniae/isolamento & purificação
12.
BMC Microbiol ; 9: 202, 2009 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-19772580

RESUMO

BACKGROUND: Crohn's disease (CD) is a high morbidity chronic inflammatory disorder of unknown aetiology. Adherent-invasive Escherichia coli (AIEC) has been recently implicated in the origin and perpetuation of CD. Because bacterial biofilms in the gut mucosa are suspected to play a role in CD and biofilm formation is a feature of certain pathogenic E. coli strains, we compared the biofilm formation capacity of 27 AIEC and 38 non-AIEC strains isolated from the intestinal mucosa. Biofilm formation capacity was then contrasted with the AIEC phenotype, the serotype, the phylotype, and the presence of virulence genes. RESULTS: Specific biofilm formation (SBF) indices were higher amongst AIEC than non-AIEC strains (P = 0.012). In addition, 65.4% of moderate to strong biofilms producers were AIEC, whereas 74.4% of weak biofilm producers were non-AIEC (P = 0.002). These data indicate that AIEC strains were more efficient biofilm producers than non-AIEC strains. Moreover, adhesion (P = 0.009) and invasion (P = 0.003) indices correlated positively with higher SBF indices. Additionally, motility (100%, P < 0.001), H1 type flagellin (53.8%, P < 0.001), serogroups O83 (19.2%, P = 0.008) and O22 (26.9%, P = 0.001), the presence of virulence genes such as sfa/focDE (38.5%, P = 0.003) and ibeA (26.9%, P = 0.017), and B2 phylotype (80.8%, P < 0.001) were frequent characteristics amongst biofilm producers. CONCLUSION: The principal contribution of the present work is the finding that biofilm formation capacity is a novel, complementary pathogenic feature of the recently described AIEC pathovar. Characterization of AIEC specific genetic determinants, and the regulatory pathways, involved in biofilm formation will likely bring new insights into AIEC pathogenesis.


Assuntos
Biofilmes , Infecções por Escherichia coli/microbiologia , Escherichia coli/genética , Mucosa Intestinal/microbiologia , Aderência Bacteriana , Linhagem Celular , Doença de Crohn/microbiologia , Escherichia coli/classificação , Escherichia coli/crescimento & desenvolvimento , Genótipo , Humanos , Fenótipo , Sorotipagem
13.
Diagn Microbiol Infect Dis ; 64(1): 52-6, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19232860

RESUMO

The in vitro activity of penicillin, ampicillin, cefditoren, cefotaxime, erythromycin, clarithromycin, and levofloxacin against 763 clinical isolates of Streptococcus pyogenes was determined. Clinically significant isolates collected from November 2005 to December 2006 in the Czech Republic, Slovakia, Hungary, Poland, Romania, Estonia, Latvia, and Lithuania (the latter 3 analyzed as Baltic countries) were studied. No resistance to beta-lactams and levofloxacin was found. The rate of erythromycin resistance in S. pyogenes varied among countries, being low (<10%) in Romania and Baltic countries, intermediate (10-20%) in Poland and Czech Republic, and high (>25%) in Hungary and Slovakia. The predominant (75.0%) erythromycin-resistant phenotype among S. pyogenes isolates was MLS(B). The identification of the prevalence of erythromycin resistance mechanism could have impact on the choice of empiric antibiotic therapy for the clinicians in such countries.


Assuntos
Antibacterianos/farmacologia , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/efeitos dos fármacos , Streptococcus pyogenes/isolamento & purificação , Adulto , Criança , Farmacorresistência Bacteriana , Europa (Continente) , Feminino , Humanos , Levofloxacino , Macrolídeos/farmacologia , Masculino , Testes de Sensibilidade Microbiana , Ofloxacino/farmacologia , Adulto Jovem , beta-Lactamas/farmacologia
14.
J Antimicrob Chemother ; 63(2): 353-6, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19056748

RESUMO

OBJECTIVES: To study the ability of Corynebacterium urealyticum to produce biofilms and to compare the in vitro activity of antimicrobials against planktonic and biofilm-associated organisms. METHODS: Biofilm formation on polystyrene plates by three C. urealyticum strains was studied in artificial urine under static conditions. The bactericidal activities of ciprofloxacin, moxifloxacin, vancomycin and erythromycin were studied against biofilm-associated organisms, and the results were compared with those obtained against planktonic organisms. Persister biofilm-associated organisms of each strain exposed to antibiotics were retested to determine the MIC of the same antibiotic. RESULTS: The three strains tested consistently produced biofilms. Planktonic organisms was susceptible to ciprofloxacin, moxifloxacin and vancomycin, and their MBC values were two to eight times higher than their corresponding MICs. Bactericidal effect on biofilm-associated organisms required very high antibiotic concentrations; the minimum biofilm bactericidal concentrations for ciprofloxacin, moxifloxacin and vancomycin ranged from 128 to > or =1024 times their respective MBCs for planktonic organisms. Erythromycin was not bactericidal against either planktonic or biofilm-associated organisms for the single susceptible strain tested. Persister biofilm-associated organisms exposed to erythromycin increased their MIC by a factor >8000, but no changes in susceptibility were observed with the other compounds. CONCLUSIONS: This work demonstrates that C. urealyticum produces biofilms on polystyrene plates and biofilm-associated organisms are much less susceptible to the bactericidal effect of the antibiotics; and the exposure of C. urealyticum to erythromycin may favour resistance selection. Overall, these results may explain the difficulties for bacterial eradication in chronic infections caused by C. urealyticum.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Corynebacterium/efeitos dos fármacos , Eritromicina/farmacologia , Quinolinas/farmacologia , Vancomicina/farmacologia , Corynebacterium/isolamento & purificação , Infecções por Corynebacterium/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana , Urina/microbiologia
15.
Microb Pathog ; 45(2): 86-91, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18486439

RESUMO

The ability of 15 Escherichia coli strains to form biofilms on polystirene plates was studied. The strains were serotyped, and their phenotypic expression of surface virulence factors (VFs), and antibiotic susceptibility was also determined. Moreover, 30 VFs-associated genes were analysed, including 15 adhesins (papC, papG and its three alleles, sfa/focDE, sfaS, focG, afa/draBC, iha, bmaE, gafD, nfaE, fimH, fimAvMT78, agn43, F9 fimbriae and type 3 fimbriae-encoding gene clusters), four toxins (hlyA, cnf1, sat and tsh), four siderophore (iron, fyuA, iutA and iucD), five proctetins/invasion-encoding genes (kpsM II, kpsMT III, K1 kps variant- neuC, traT and ibeA), and the pathogenicity island malX and cvaC. Morphological appearance and thickness of biofilms of two strong and three weak biofilm producers were also studied by confocal laser scanning microscopy (CLSM). Seven strains were classified as strong biofilm producers and the remaining eight strains were regarded as weak biofilm producers. Mannose-resistant haemagglutination was the only phenotypically expressed surface virulence factor more frequently found in the strong biofilm group. Five virulence-associated genes were more common (p<0.05) in strong biofilm producers: papC and papG alleles, sfa/focDE, focG, hlyA and cnf1. CLSM images showed irregular biofilms with projections at the top mainly in strong biofilm.


Assuntos
Biofilmes/crescimento & desenvolvimento , Escherichia coli/genética , Escherichia coli/patogenicidade , Fatores de Virulência/metabolismo , Virulência/fisiologia , Aderência Bacteriana/fisiologia , Escherichia coli/classificação , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Microscopia Confocal , Virulência/genética , Fatores de Virulência/genética
16.
Rev. bras. anal. clin ; 38(3): 189-192, jul.-set . 2006. tab
Artigo em Português | LILACS | ID: lil-461310

RESUMO

A cromoblastomicose é uma infecção localizada crônica da pele e tecido subcutâneo preferencialmente envolvendo membros inferiores e caracterizada por lesões geralmente verrucosas. Em muitos casos, as lesões são unilaterais e são causadas por fungos dematiáceos. A doença é muito comum em regiões tropical e subtropical. Os agentes etiológicos de cromoblastomicose são dispersos no meio ambiente, sendo encontrados no solo e na vegetação em decomposição. A infecção ocorre pela inoculação traumática do fungo na pele e a micose é muito prevalecente entre indivíduos com ocupações ao ar livre e que andam dascalços, sendo comum nos homens. Ainda é uma doença fúngica presente principalmente na população rural brasileira.


Assuntos
Humanos , Cromoblastomicose , Micoses , Verrugas , Fungos , Extremidade Inferior , Prevalência
17.
Acta Med Port ; 15(3): 171-4, 2002.
Artigo em Português | MEDLINE | ID: mdl-12379993

RESUMO

The childhood is one of the most propitious period of the life to the occurrence of infection by yeasts of the genus Candida. In children with Down's syndrome, besides the predispose factors to bucal candidiasis; macroglossia, bucal muscular incompetence, frequent respiratory diseases, motor difficulty and immunologic deficit are mentioned as additional elements for this fungus disease. It was verified that the children attacked by this syndrome have much more strains of Candida than other children. The aim of this study was to detect the prevalence of phospholipase producer, Candida on the saliva of children with Down's syndrome. Candida albicans was the only identified specie of Candida. The phospholipase production was found in isolated strains from both of study and control. However, the isolated strains of the group of children with Down's syndrome have strongly present phospholipidolitic.


Assuntos
Candida albicans/enzimologia , Síndrome de Down/microbiologia , Fosfolipases/metabolismo , Saliva/microbiologia , Candida albicans/isolamento & purificação , Criança , Pré-Escolar , Humanos , Lactente
18.
ROBRAC ; 8(26): 43-4, dez. 1999. graf
Artigo em Português | LILACS, BBO - Odontologia | ID: lil-283604

RESUMO

Os fungos säo tidos como um dos microrganismos mais dispersos pelo ar. A contaminaçäo ambiental fúngica, além de ser frequente, proporciona a açäo destes seres vivos como agentes patogênicos de doenças respiratórias e oportunistas. Este estudo objetivou avaliar a contaminaçäo fúngica do ar da Clínica de Periodontia da Faculdade de Odontologia da Universidade Federal de Goiás (FO/UFG). As amostras foram coletadas em placas de Petri aberta, contendo ágar infusão cérebro-coraçäo, mediante a sua exposiçäo ao ambiente por 30 minutos, após atendimento dos pacientes. As colônias fúngicas desenvolvidas foram repicadas em ágar Sabouraud e identificadas por características macroscópicas e microcultivo. Os fungos detectados compreenderam 6 cepas de Aspergillus sp.;1 de Penicillium sp.; 1 de Curvularia sp.; 1 de Mycella sterelia; 1 Botrytis sp. e 2 fungos filamentosos negros; além de um isolado bacteriano Nocardia sp. O resultado mostrou que as condiçöes ambientais da clínica de Periodontia não estavam adequadas e medidas de controle devem ser revistas


Assuntos
Poluição Ambiental , Clínicas Odontológicas , Fungos , Periodontia
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