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1.
J Fungi (Basel) ; 7(9)2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34575801

RESUMO

Candida auris is an emerging healthcare-associated fungal pathogen that has become a serious global health threat. Current treatment options are limited due to drug resistance. New therapeutic strategies are required to target this organism and its pathogenicity. Plant polyphenols are structurally diverse compounds that present a vast range of biological properties. In the present study, plant-derived molecules ellagic acid (EA) and caffeic acid phenethyl ester (CAPE) were investigated for their antifungal and antivirulence activities against Candida auris. We also tested against C. albicans. The minimum inhibitory concentration (MIC) for EA ranged from 0.125 to 0.25 µg/mL and for CAPE ranged from 1 to 64 µg/mL against drug-resistant C. auris strains. Killing kinetics determined that after 4 h treatment with CAPE, there was a complete reduction of viable C. auris cells compared to fluconazole. Both compounds might act by modifying the fungal cell wall. CAPE significantly reduced the biomass and the metabolic activity of C. auris biofilm and impaired C. auris adhesion to cultured human epithelial cells. Furthermore, both compounds prolonged the survival rate of Galleria mellonella infected by C. auris (p = 0.0088 for EA at 32 mg/kg and p = 0.0028 for CAPE at 4 mg/kg). In addition, EA at 4 µg/mL prolonged the survival of C. albicans-infected Caenorhabditis elegans (p < 0.0001). CAPE was not able to prolong the survival of C. albicans-infected C. elegans. These findings highlight the antifungal and antivirulence effects of EA and CAPE against C. auris, and warrant further investigation as novel antifungal agents against drug-resistant infections.

2.
Rev. Soc. Bras. Med. Trop ; 51(3): 361-363, Apr.-June 2018. graf
Artigo em Inglês | LILACS | ID: biblio-1041462

RESUMO

Abstract INTRODUCTION: The pathogenic versatility of Staphylococcus aureus is attributed to various virulence genes, including enterotoxins and hemolysins. METHODS: Here, the virulence genes in 177 nosocomial MRSA strains in Porto Alegre, Brazil were detected by PCR. RESULTS: The overall prevalence rates were as follows: sea, 4.5%; pvl, 18.6%; tst, 27.7%; hla, 87.6%; and hld, 90.4%. No strain contained all tested genes. However, there was frequent coexistence of tst with pvl and hla with hld (40.7% and 26.6%, respectively). CONCLUSIONS: Horizontal transfer of virulence genes is very common in S. aureus, as suggested by the frequent coexistence of several virulence genes.


Assuntos
Humanos , Virulência/genética , Fatores de Virulência/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Reação em Cadeia da Polimerase , Estudos Transversais , Staphylococcus aureus Resistente à Meticilina/genética
3.
Braz. j. microbiol ; 48(4): 782-784, Oct.-Dec. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1039266

RESUMO

ABSTRACT Rapid identification of vancomycin-resistant enterococci (VRE) can assist in choosing the appropriate treatment and preventing VRE spread. The performance of chromIDTM VRE agar was evaluated using 184 clinical isolates of Enterococcus spp. and reference strains. The test had a sensitivity of 95.52% but a low specificity of 30%.


Assuntos
Humanos , Técnicas Bacteriológicas/métodos , Infecções por Bactérias Gram-Positivas/microbiologia , Meios de Cultura/química , Enterococos Resistentes à Vancomicina/crescimento & desenvolvimento , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Técnicas Bacteriológicas/instrumentação , Meios de Cultura/metabolismo , Fezes/microbiologia , Enterococos Resistentes à Vancomicina/metabolismo
4.
An. bras. dermatol ; 91(5): 604-610, Sept.-Oct. 2016. tab, graf
Artigo em Inglês | LILACS | ID: biblio-827754

RESUMO

Abstract: Background: Topical antimicrobial drugs are indicated for limited superficial pyodermitis treatment, although they are largely used as self-prescribed medication for a variety of inflammatory dermatoses, including atopic dermatitis. Monitoring bacterial susceptibility to these drugs is difficult, given the paucity of laboratory standardization. Objective: To evaluate the prevalence of Staphylococcus aureus topical antimicrobial drug resistance in atopic dermatitis patients. Methods: We conducted a cross-sectional study of children and adults diagnosed with atopic dermatitis and S. aureus colonization. We used miscellaneous literature reported breakpoints to define S. aureus resistance to mupirocin, fusidic acid, gentamicin, neomycin and bacitracin. Results: A total of 91 patients were included and 100 S. aureus isolates were analyzed. All strains were methicillin-susceptible S. aureus. We found a low prevalence of mupirocin and fusidic acid resistance (1.1% and 5.9%, respectively), but high levels of neomycin and bacitracin resistance (42.6% and 100%, respectively). Fusidic acid resistance was associated with more severe atopic dermatitis, demonstrated by higher EASI scores (median 17.8 vs 5.7, p=.009). Our results also corroborate the literature on the absence of cross-resistance between the aminoglycosides neomycin and gentamicin. Conclusions: Our data, in a southern Brazilian sample of AD patients, revealed a low prevalence of mupirocin and fusidic acid resistance of S. aureus atopic eczema colonizer strains. However, for neomycin and bacitracin, which are commonly used topical antimicrobial drugs in Brazil, high levels of resistance were identified. Further restrictions on the use of these antimicrobials seem necessary to keep resistance as low as possible.


Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Adulto Jovem , Staphylococcus aureus/efeitos dos fármacos , Farmacorresistência Bacteriana , Dermatite Atópica/microbiologia , Antibacterianos/farmacologia , Bacitracina/farmacologia , Gentamicinas/farmacologia , Neomicina/farmacologia , Estudos Transversais , Mupirocina/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/métodos , Ácido Fusídico/farmacologia
5.
Rev. Soc. Bras. Med. Trop ; 49(3): 292-299, tab, graf
Artigo em Inglês | LILACS | ID: lil-785791

RESUMO

Abstract: INTRODUCTION: Coagulase-negative staphylococci (CoNS) are the most prevalent pathogens in nosocomial infections and may serve as a reservoir of mobile genetic elements such as the staphylococcal cassette chromosome mec (SCCmec) encoding methicillin resistance. Molecular characterization of SCCmec types combined with advanced molecular typing techniques may provide essential information for understanding the evolution and epidemiology of CoNS infections. We therefore aimed to investigate the SCCmec distribution, multidrug-resistance (MDR), and biofilm formation in CoNS blood culture isolates from a hospital in Southern Brazil. METHODS: We analyzed 136 CoNS blood culture isolates obtained during 2002-2004 from patients admitted to a tertiary care hospital in Brazil. SCCmec types I to V were determined using multiplex PCR. The clonal relationship of Staphylococcus epidermidis was determined using pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Molecular epidemiological data were interpreted along with data on biofilm formation, presence of the icaD gene, and MDR. RESULTS: The most prevalent species were S. epidermidis, Staphylococcus haemolyticus, and Staphylococcus hominis harboring mainly SCCmec types II, III, and V. Overall, the presence of multiple SCCmec was associated with non-MDR, except for S. epidermidis. S. epidermidis isolates showed a high prevalence of icaD, but had low phenotypic biofilm formation. PFGE and MLST revealed high genetic diversity in the S. epidermidis population. CONCLUSIONS: Our results suggest a major shift in SCCmec types within a short period and reveal a different behavior of S. epidermidis with regard to the association between the presence of multiple SCCmec types and MDR profile.


Assuntos
Humanos , Staphylococcus/classificação , Variação Genética/genética , DNA Bacteriano/genética , Cromossomos Bacterianos/genética , Staphylococcus/enzimologia , Staphylococcus/genética , Eletroforese em Gel de Campo Pulsado , Coagulase/biossíntese , Biofilmes/crescimento & desenvolvimento , Tipagem de Sequências Multilocus
6.
Clin. biomed. res ; 36(3): 142-147, 2016. ilus, tab
Artigo em Português | LILACS | ID: biblio-831713

RESUMO

Introdução: A paracoccidioidomicose (PCM) é uma micose sistêmica endêmica causada pelo fungo Paracoccidioides spp. O objetivo deste estudo foi determinar a associação entre tuberculose (TB) e PCM em pacientes com exame micológico negativo. Métodos: Estudo prospectivo de diagnóstico molecular de amostras de escarro, com resultado positivo para bacilo álcool ácido resistente (BAAR) e negativo no exame direto e cultivo micológico. Resultados: A aplicação de técnicas moleculares resultou em 18,4% de pacientes coinfectados com PCM e TB. Conclusão: O conhecimento das diferenças clínicas, epidemiológicas e laboratoriais da PCM quando associada à TB é importante para prevenir a disseminação da doença, complicações e o aumento da letalidade (AU)


Introduction: Paracoccidioidomycosis (PCM) is a systemic endemic mycosis caused by Paracoccidioides spp. The aim of this study was to determine the association between tuberculosis (TB) and PCM in patients with negative mycological examination results. Methods: Prospective study of molecular diagnosis of sputum samples, with positive results for bacilli resistant acid (BAAR) and negative results on direct examination and mycological culture. Results: The application of molecular techniques resulted in 18.4% of patients co-infected with PCM and TB. Conclusion: The knowledge of clinical, epidemiological, and laboratory differences of PCM when associated with TB is important to prevent the spread of disease, complications, and increased mortality (AU)


Assuntos
Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Paracoccidioidomicose/diagnóstico , Escarro/microbiologia , Tuberculose/diagnóstico , Diagnóstico Diferencial , Paracoccidioides/genética , Paracoccidioidomicose/microbiologia , Estudos Prospectivos
7.
Braz. j. infect. dis ; 19(5): 466-472, tab, graf
Artigo em Inglês | LILACS | ID: lil-764503

RESUMO

ABSTRACTTo determine the epidemiological and molecular characteristics of 12 Staphylococcus aureus isolates presenting heteroresistance to vancomycin in laboratories of two cities in Santa Catarina, southern Brazil. Epidemiological data, including the city of isolation, health institution, and date of isolation were considered, as well as the associated clinical specimen. For molecular characterization, we analyzed the staphylococcal cassette chromosome types, the erm gene presence, and the genomic diversity of isolates using pulsed-field gel electrophoresis. The 12 isolates of S. aureus were previously confirmed as heteroresistance to vancomycin using the population analysis profile-area under curve. Regarding genetic variability, two clones were detected: the main one (clone A) composed of four isolates and the clones B, with two isolates. For clone A, two isolates presented identical band patterns and were related to the same hospital, with an interval of 57 days between their isolation. The other isolates of this clone showed no epidemiological link between them because they were isolated in different hospitals and had no temporal relationship. The other clone showed no detectable epidemiological relationship. The heteroresistance to vancomycin recovered in Santa Catarina State from 2009 to 2012 had, in general, heterogeneous genomic patterns based on pulsed-field gel electrophoresis results, which is in accordance with the fact that these isolates had little or no epidemiological relationship among them. Due to the characteristic phenotypic instability and often prolonged vancomycin therapy for selection, clonal spread is not as common as for other resistance mechanisms disseminated through horizontal gene transfer.


Assuntos
Humanos , Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Vancomicina/farmacologia , Técnicas de Tipagem Bacteriana , Brasil/epidemiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , DNA Bacteriano/análise , Eletroforese em Gel de Campo Pulsado , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Reação em Cadeia da Polimerase Multiplex , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/genética , Fenótipo , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia
8.
Rev. Inst. Med. Trop. Säo Paulo ; 56(6): 469-472, Nov-Dec/2014. tab
Artigo em Inglês | LILACS | ID: lil-725813

RESUMO

INTRODUCTION: Methicillin-Resistant Staphylococcus aureus (MRSA) presenting reduced susceptibility to vancomycin has been associated to therapeutic failure. Some methods used by clinical laboratories may not be sufficiently accurate to detect this phenotype, compromising results and the outcome of the patient. OBJECTIVES: To evaluate the performance of methods in the detection of vancomycin MIC values among clinical isolates of MRSA. MATERIAL AND METHODS: The Vancomycin Minimal Inhibitory Concentration was determined for 75 MRSA isolates from inpatients of Mãe de Deus Hospital, Porto Alegre, Brazil. The broth microdilution (BM) was used as the gold-standard technique, as well as the following methods: E-test® strips (BioMérieux), M.I.C.E® strips (Oxoid), PROBAC® commercial panel and the automated system MicroScan® (Siemens). Besides, the agar screening test was carried out with 3 µg/mL of vancomycin. RESULTS: All isolates presented MIC ≤ 2 µg/mL for BM. E-test® had higher concordance (40%) in terms of global agreement with the gold standard, and there was not statistical difference among E-test® and broth microdilution results. PROBAC® panels presented MICs, in general, lower than the gold-standard panels (58.66% major errors), while M.I.C.E.® MICs were higher (67.99% minor errors). CONCLUSIONS: For the population of MRSA in question, E-test® presented the best performance, although with a heterogeneous accuracy, depending on MIC values.


INTRODUÇÃO: Staphylococcus aureus resistente à meticilina (MRSA) apresentando suscetibilidade reduzida à vancomicina tem sido associado à falha terapêutica. Alguns métodos utilizados por laboratórios clínicos podem não ser suficientemente precisos para detectar este fenótipo, comprometendo os resultados e o desfecho do paciente. OBJETIVOS: Avaliar o desempenho de métodos na detecção dos valores de MIC de vancomicina entre isolados clínicos de MRSA. MATERIAIS E MÉTODOS: Determinamos a Concentração Inibitória Mínima de Vancomicina para 75 MRSA isolados de pacientes do Hospital Mãe de Deus, Porto Alegre, Brasil. Utilizamos a microdiluição em caldo como técnica padrão-ouro e os seguintes métodos: tiras de E-test® (BioMérieux), tiras M.I.C.E® (Oxoid), painel comercial da PROBAC® e sistema automatizado MicroScan® (Siemens). Além disso, foi realizado o teste de triagem em ágar com 3 µg/mL de vancomicina. RESULTADOS: Todos os isolados apresentaram MIC ≤ 2 µg/mL. Não houve diferença estatística entre os resultados do E-test® e da microdiluição em caldo. O painel da PROBAC® apresentou MICs, em geral, menores que o padrão-ouro (58,66% de erros maiores), enquanto que as MICs pelo M.I.C.E.® foram maiores (67,99% de erros menores). CONCLUSÕES: Para nossa população de MRSA, E-test® apresentou o melhor desempenho, embora com uma acurácia heterogênea, dependendo dos valores da MIC.


Assuntos
Humanos , Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Vancomicina/farmacologia , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana/métodos
9.
J. vasc. bras ; 13(3): 175-181, Jul-Sep/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-727129

RESUMO

Background: Surgical site infection is a severe complication of peripheral vascular surgery with high morbidity and mortality rates. Objective: To evaluate the morbidity and mortality of infections of peripheral artery surgery sites caused by resistant microorganisms. Methods: This was a prospective study of a cohort of patients who underwent peripheral artery revascularization procedures and developed surgical site infections between March 2007 and March 2011. Results: Mean age was 63.7 years; males accounted for 64.3% of all cases. The overall prevalence of bacterial resistance to antimicrobials was 65.7%. The most common microorganism identified was Staphylococcus aureus (30%). Comparison of the demographic and surgical characteristics of both subsets (resistant versus non-resistant) detected a significant difference in length of preoperative hospital stay (9.3 days vs. 3.7 days). The subset of patients with infections by resistant microorganisms had higher rates of reoperation, lower numbers of limb amputations and lower mortality, but the differences compared to the subset without resistant infections were not significant. Long-term survival was similar. Conclusions: This study detected no statistically significant differences in morbidity or mortality between subsets with surgical wound infections caused by resistant and not-resistant microorganisms...


Contexto: A infecção de ferida operatória é uma complicação grave da cirurgia vascular periférica e está associada a elevadas taxas de morbidade e mortalidade. Objetivo: Avaliar a morbidade e a mortalidade relacionadas às infecções de ferida operatória causadas por micro-organismos resistentes em cirurgias arteriais periféricas. Métodos: Coorte prospectiva envolvendo pacientes submetidos a procedimentos de revascularização arterial periférica que desenvolveram infecção de sítio cirúrgico, entre março de 2007 e março de 2011. Resultados: A média de idade desses pacientes foi de 63,7 anos; homens representaram 64,3% de todos os casos. A prevalência total de resistência bacteriana foi de 65,7%. O micro-organismo mais isolado foi o Staphylococcus aureus (30%). Comparando-se as características demográficas e cirúrgicas das duas amostras (com e sem resistência), foi demonstrado que o tempo de permanência hospitalar apresentou diferença significativa (9,3 dias × 3,7 dias). O grupo de pacientes portadores de infecção por micro-organismo resistente apresentou elevadas taxas de reoperação, amputação de membro inferior e mortalidade, porém sem diferença estatística quando comparado ao grupo sem resistência. No longo prazo, a sobrevida foi similar. Conclusão: este estudo não demonstrou diferença estatística quanto a morbidade e mortalidade entre os grupos com infecção de ferida operatória ocasionada por micro-organismos resistentes e não resistentes...


Assuntos
Doenças Vasculares Periféricas/cirurgia , Doenças Vasculares Periféricas/complicações , Infecção da Ferida Cirúrgica/diagnóstico , Resistência a Medicamentos , Infecções Bacterianas/transmissão , Estudos Prospectivos , Staphylococcus aureus
10.
Mem. Inst. Oswaldo Cruz ; 109(4): 408-413, 03/07/2014. graf
Artigo em Inglês | LILACS | ID: lil-716304

RESUMO

The Firmicutes bacteria participate extensively in virulence and pathological processes. Enterococcus faecalis is a commensal microorganism; however, it is also a pathogenic bacterium mainly associated with nosocomial infections in immunocompromised patients. Iron-sulfur [Fe-S] clusters are inorganic prosthetic groups involved in diverse biological processes, whose in vivo formation requires several specific protein machineries. Escherichia coli is one of the most frequently studied microorganisms regarding [Fe-S] cluster biogenesis and encodes the iron-sulfur cluster and sulfur assimilation systems. In Firmicutes species, a unique operon composed of the sufCDSUB genes is responsible for [Fe-S] cluster biogenesis. The aim of this study was to investigate the potential of the E. faecalis sufCDSUB system in the [Fe-S] cluster assembly using oxidative stress and iron depletion as adverse growth conditions. Quantitative real-time polymerase chain reaction demonstrated, for the first time, that Gram-positive bacteria possess an OxyR component responsive to oxidative stress conditions, as fully described for E. coli models. Likewise, strong expression of the sufCDSUB genes was observed in low concentrations of hydrogen peroxide, indicating that the lowest concentration of oxygen free radicals inside cells, known to be highly damaging to [Fe-S] clusters, is sufficient to trigger the transcriptional machinery for prompt replacement of [Fe-S] clusters.


Assuntos
Enterococcus faecalis/metabolismo , Proteínas Ferro-Enxofre/genética , Estresse Oxidativo , Vias Biossintéticas , Proteínas Ferro-Enxofre/biossíntese , Modelos Moleculares , Reação em Cadeia da Polimerase em Tempo Real , Especificidade por Substrato
11.
Mem Inst Oswaldo Cruz ; 109(4): 408-13, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24936909

RESUMO

The Firmicutes bacteria participate extensively in virulence and pathological processes. Enterococcus faecalis is a commensal microorganism; however, it is also a pathogenic bacterium mainly associated with nosocomial infections in immunocompromised patients. Iron-sulfur [Fe-S] clusters are inorganic prosthetic groups involved in diverse biological processes, whose in vivo formation requires several specific protein machineries. Escherichia coli is one of the most frequently studied microorganisms regarding [Fe-S] cluster biogenesis and encodes the iron-sulfur cluster and sulfur assimilation systems. In Firmicutes species, a unique operon composed of the sufCDSUB genes is responsible for [Fe-S] cluster biogenesis. The aim of this study was to investigate the potential of the E. faecalis sufCDSUB system in the [Fe-S] cluster assembly using oxidative stress and iron depletion as adverse growth conditions. Quantitative real-time polymerase chain reaction demonstrated, for the first time, that Gram-positive bacteria possess an OxyR component responsive to oxidative stress conditions, as fully described for E. coli models. Likewise, strong expression of the sufCDSUB genes was observed in low concentrations of hydrogen peroxide, indicating that the lowest concentration of oxygen free radicals inside cells, known to be highly damaging to [Fe-S] clusters, is sufficient to trigger the transcriptional machinery for prompt replacement of [Fe-S] clusters.


Assuntos
Enterococcus faecalis/metabolismo , Proteínas Ferro-Enxofre/genética , Estresse Oxidativo , Vias Biossintéticas , Proteínas Ferro-Enxofre/biossíntese , Modelos Moleculares , Reação em Cadeia da Polimerase em Tempo Real , Especificidade por Substrato
12.
An. bras. dermatol ; 89(3): 404-408, May-Jun/2014. tab
Artigo em Inglês | LILACS | ID: lil-711615

RESUMO

BACKGROUND: One of the most stigmatizing physical sequelaeof leprosy in cured patients is the development of chronic lower extremity ulcers. The bacterial diversity present in ulcers is considered one of the factors that can delay the healing process, as well as serve as a focus for severe secondary infections. OBJECTIVE: To identify the microbiota and antimicrobial resistance profile of bacteria isolated from skin ulcers in patients cured of leprosy. METHODS: After obtaining informed consent, material was collected from ulcers of 16 patients treated at the Outpatient Public Health Dermatology Clinic of Rio Grande do Sul and Hospital Colônia Itapuã. Sampleswere collected during dressing, and the material sent to the Microbiology Laboratory of the Federal University of Health Sciences of Porto Alegre for microbiological culture. Methicillin-resistant Staphylococcus aureus (MRSA) was characterized by two molecular methods, including detection of the mecA gene by PCR and SCCmecgene typing. RESULTS: Cultures revealed microorganisms in all ulcers: Gram-negative bacilli in 80%, Gram-positive cocci in 63%, and mixed microflora in 36%. Staphylococcus aureus and Pseudomonas aeruginosa were the most prevalent bacteria. Assessment of the antimicrobial resistance profile was notable for the presence of MRSA. Molecular analysis of this isolate revealed presence of the mecA gene contained in a type IV staphylococcal cassette chromosome mec (SCCmec). CONCLUSIONS: In patients with leprosy, laboratory culture of skin ulcers is essential for correct antibiotic selection and to control emerging pathogens, such as MRSA carrying SCCmec type IV. .


Assuntos
Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Bactérias/isolamento & purificação , Hanseníase/complicações , Úlcera Cutânea/microbiologia , Infecções Estafilocócicas/microbiologia , Técnicas de Tipagem Bacteriana , Brasil , Bactérias/genética , Doença Crônica , Úlcera da Perna/microbiologia , Extremidade Inferior/microbiologia , Testes de Sensibilidade Microbiana , Microbiota , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Reação em Cadeia da Polimerase , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/isolamento & purificação
13.
Rev. Inst. Med. Trop. Säo Paulo ; 56(1): 29-33, Jan-Feb/2014. tab
Artigo em Inglês | LILACS | ID: lil-702060

RESUMO

Currently there are several methods to extract bacterial DNA based on different principles. However, the amount and the quality of the DNA obtained by each one of those methods is highly variable and microorganism dependent, as illustrated by coagulase-negative staphylococci (CoNS) which have a thick cell wall that is difficult to lyse. This study was designed to compare the quality and the amount of CoNS DNA, extracted by four different techniques: two in-house protocols and two commercial kits. DNA amount and quality determination was performed through spectrophotometry. The extracted DNA was also analyzed using agarose gel electrophoresis and by PCR. 267 isolates of CoNS were used in this study. The column method and thermal lyses showed better results with regard to DNA quality (mean ratio of A260/280 = 1.95) and average concentration of DNA (), respectively. All four methods tested provided appropriate DNA for PCR amplification, but with different yields. DNA quality is important since it allows the application of a large number of molecular biology techniques, and also it's storage for a longer period of time. In this sense the extraction method based on an extraction column presented the best results for CoNS.


Atualmente, para extrair o DNA bacteriano, existem diversos métodos baseados em diferentes princípios. Entretanto, a quantidade e qualidade do DNA obtido por cada um destes métodos é variável e depende do tipo de micro-organismo em questão; os estafilococos coagulase-negativos (CoNS), por exemplo, possuem parede celular espessa difícil de lisar. O objetivo deste estudo foi comparar a quantidade e a qualidade do DNA extraído de isolados clínicos de CoNS utilizando quatro metodologias diferentes: dois protocolos caseiros e dois kits comerciais. A determinação da quantidade e da qualidade do DNA foi realizada por espectrofotometria. O DNA extraído também foi analisado em eletroforese em gel de agarose e por PCR. A concentração média de DNA foi mais alta no método de lise térmica (). Entretanto, com relação à qualidade do DNA, o kit comercial que utiliza um método de extração baseado em uma coluna de separação apresentou melhor resultado (média da relação A260/280 = 1,95). As quatro técnicas testadas forneceram DNA passível de amplificação por PCR, porém com diferentes rendimentos. A qualidade do DNA extraído de bactérias é importante, pois possibilita a realização de maior número de técnicas de biologia molecular e também armazenamento do material por maior período de tempo. Neste sentido, a técnica de extração por coluna de separação apresentou melhor desempenho frente aos CoNS.


Assuntos
Humanos , Coagulase , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Manejo de Espécimes/métodos , Staphylococcus/enzimologia , Staphylococcus/genética , Técnicas de Tipagem Bacteriana , Eletroforese em Gel de Campo Pulsado , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes , Staphylococcus/classificação
14.
Clin. biomed. res ; 34(3): 281-286, 2014. tab, graf
Artigo em Inglês | LILACS | ID: biblio-834465

RESUMO

Introduction: Enterococci have become the third leading cause of nosocomial bacteraemia, an infection which is significantly associated with the risk of developing infective endocarditis. Linezolid provides high rates of clinical cure and microbiologic success in complicated infections due to Enterococcus spp. However, several instances of emergence of resistance during linezolid treatment have been reported. The aim of this study was evaluate the activity of tigecycline against linezolidintermediate (LIE) and linezolid-resistant enterococcus faecalis(LRE) by the timekill assay. Methods: Five isolates of LRE and two isolates of LIE were used in this study. Minimum inhibitory concentration (MIC) was determined by broth dilution following the guidelines from the Clinical and Laboratory Standards Institute (CLSI). Time-kill assay was employed to access the in vitro response profile of tigecycline. Results: All seven isolates presented MIC of 0.125 ìg/mL. Tigecycline activity was individually evaluated according to CLSI criteria. This antibiotic showed bactericidal activity against three of the five isolates of LRE and bacteriostatic activity against the other isolates. Conclusions: Tigecycline presented both bacteriostatic and bactericidal activity against tested isolates, which is an important data that must be considered for new studies.


Assuntos
Humanos , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Antibacterianos/química , Antibacterianos/síntese química , Enterococcus faecalis , Minociclina/análogos & derivados , Minociclina/farmacologia , Meios de Cultura
15.
Clin. biomed. res ; 34(2): 97-112, 2014. tab
Artigo em Inglês | LILACS | ID: biblio-997850

RESUMO

Infections caused by Streptococcus pneumoniae are a worrisome public health problem worldwide. Young children and the elderly are the main age groups affected and the highest burden of the disease is found in developing countries. Pneumococcal infections cause 11% of the total infant deaths, representing the leading cause of child death currently preventable by vaccination. Epidemiologic information about pneumococci in Brazil is somehow restricted, but available data reinforce the worrisome occurrence of pneumococcal diseases, which are commonly treated empirically. Limitations in the diagnostic methods, along with the severity of disease contribute to this behavior. Thus, surveillance studies are crucial to define the prevalence of resistant strains both globally and in a particular region, as these strains may compromise empirical therapeutic choices. However, although different clones of penicillin non-susceptible pneumococci are internationally distributed, and considering diseases other than meningitis, the prevalence of resistance to penicillin is quite low, making this old, safe, and inexpensive drug an attractive first choice to treat pneumococcal infections. The widespread use of conjugate vaccines among children, influencing the circulation of resistant clones and the distribution of serotypes reinforces the need of surveillance studies to define the prevalence of resistance


Assuntos
Humanos , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/efeitos dos fármacos , Resistência Microbiana a Medicamentos , Farmacorresistência Bacteriana , Antibacterianos , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/tratamento farmacológico , Infecções Pneumocócicas/epidemiologia , Sorologia/métodos , Testes de Sensibilidade Microbiana
16.
Mem. Inst. Oswaldo Cruz ; 108(5): 590-595, ago. 2013. tab
Artigo em Inglês | LILACS | ID: lil-680773

RESUMO

Despite the increasing importance of Enterococcus as opportunistic pathogens, their virulence factors are still poorly understood. This study determines the frequency of virulence factors in clinical and commensal Enterococcus isolates from inpatients in Porto Alegre, Brazil. Fifty Enterococcus isolates were analysed and the presence of the gelE, asa1 and esp genes was determined. Gelatinase activity and biofilm formation were also tested. The clonal relationships among the isolates were evaluated using pulsed-field gel electrophoresis. The asa1, gelE and esp genes were identified in 38%, 60% and 76% of all isolates, respectively. The first two genes were more prevalent in Enterococcus faecalis than in Enterococcus faecium, as was biofilm formation, which was associated with gelE and asa1 genes, but not with the esp gene. The presence of gelE and the activity of gelatinase were not fully concordant. No relationship was observed among any virulence factors and specific subclones of E. faecalis or E. faecium resistant to vancomycin. In conclusion, E. faecalis and E. faecium isolates showed significantly different patterns of virulence determinants. Neither the source of isolation nor the clonal relationship or vancomycin resistance influenced their distribution.


Assuntos
Antibacterianos/farmacologia , Enterococcus faecalis , Enterococcus faecium , Vancomicina/farmacologia , Fatores de Virulência/genética , Biofilmes/crescimento & desenvolvimento , Eletroforese em Gel de Campo Pulsado , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/enzimologia , Enterococcus faecalis/patogenicidade , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/enzimologia , Enterococcus faecium/patogenicidade , Gelatinases/metabolismo , Testes de Sensibilidade Microbiana , Resistência a Vancomicina/genética
17.
An. bras. dermatol ; 88(4): 518-521, ago. 2013.
Artigo em Inglês | LILACS | ID: lil-686523

RESUMO

BACKGROUND: Atopic dermatitis leads to epidermal barrier dysfunction and bacteria colonization. The relationship of the last factor with the severity of the disease and the frequency of exacerbation is not fully known. OBJECTIVES: Verify the severity of the atopic dermatitis and the number of appointments generated by dermatosis, comparing patients colonized with patients not colonized by S. aureus. Verify the frequency of colonization by methicillin resistant Staphylococcus aureus acquired in the community. METHODS: Cohort study with a 12 months follow-up, in a sample of patients from Porto Alegre, RS public network. Cultures in active injuries and nasal cavities were carried out as well as methicillin sensitivity tests to S. aureus. The severity of atopic dermatitis was defined by Eczema Area and Severity Index (EASI). RESULTS: We included 93 patients, 43% female and 56% male, 26 colonized by S. aureus in the nasal orifices, 56 in the skin damage. The mean of initial Eczema Area and Severity Index was 5.5 and final 3.9. The initial Eczema Area and Severity Index of patients colonized by S. aureus in the skin and nasal cavity was larger than the number of patients without colonization(p< 0.05). During the period of one year, in average, there were six appointments/patient. There was linear correlation between the number of appointments during one year and the inicial Eczema Area and Severity Index (r = 0,78). There were no patients ...


FUNDAMENTOS: A Dermatite Atópica cursa com alteração da barreira cutânea e colonização bacteriana; a relação deste último fator com a gravidade da doença e a frequência das exacerbações não é completamente conhecida. OBJETIVOS: Verificar a gravidade da Dermatite Atópica e o número de consultas ocasionadas pela dermatose, comparando pacientes colonizados e não colonizados pelo Staphylococcus aureus (S. aureus). Verificar a frequência de colonização por Staphylococcus aureus meticilina resistentes da comunidade. MÉTODOS: Estudo de coorte, com 12 meses de acompanhamento, em amostra de pacientes da rede pública de Porto Alegre, RS. Realizaram-se culturais de lesões ativas e fossas nasais e testes de sensibilidade à meticilina para o S. aureus. A gravidade da Dermatite Atópica foi estabelecida pelo Eczema Area and Severity Index. RESULTADOS: Incluídos 93 pacientes, 43% femininos e 56% masculinos, 26 colonizados por S. aureus na região nasal, 56 em lesão cutânea. A média do Eczema Area and Severity inicial foi 5,5 e a do final 3,9. O Eczema Area and Severity Index inicial dos pacientes colonizados por S. aureus em lesão cutânea e nas fossas nasais foi maior que o dos pacientes não colonizados (p< 0,05). Em um ano, seis consultas por paciente ocorreram, em média. Houve correlação linear entre ...


Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Adulto Jovem , Agendamento de Consultas , Dermatite Atópica/microbiologia , Índice de Gravidade de Doença , Staphylococcus aureus/crescimento & desenvolvimento , Estudos de Coortes , Dermatite Atópica/patologia , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Pele/microbiologia , Fatores de Tempo
18.
Mem. Inst. Oswaldo Cruz ; 108(4): 453-456, jun. 2013. tab
Artigo em Inglês | LILACS | ID: lil-678299

RESUMO

Here we report the presence and expression levels of the vanC 1 and vanC 2/3 genes in vancomycin-susceptible strains of Enterococcus faecalis. The vanC 1 and vanC 2/3 genes were located in the plasmid DNA and on the chromosome, respectively. Specific mRNA of the vanC 1 gene was detected in one of these strains. Additionally, analysis of the vanC gene sequences showed that these genes are related to the vanC genes of Enterococcus gallinarum and Enterococcus casseliflavus. The presence of vanC genes is useful for the identification of E. gallinarum and E. casseliflavus. Moreover, this is the first report of vanC mRNA in E. faecalis.


Assuntos
Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/genética , Resistência a Vancomicina/genética , Vancomicina/farmacologia , Galinhas , Cloaca/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , DNA Bacteriano/análise , Enterococcus faecalis/isolamento & purificação , Genes Bacterianos/genética , Reação em Cadeia da Polimerase em Tempo Real
19.
São Paulo med. j ; 131(1): 59-61, mar. 2013. tab
Artigo em Inglês | LILACS | ID: lil-668876

RESUMO

CONTEXT

Coagulase-negative staphylococci are common colonizers of the human skin and have become increasingly recognized as agents of clinically significant nosocomial infections. CASE REPORT

The case of a 79-year-old male patient with multi-infarct dementia who presented systemic inflammatory response syndrome is reported. This was attributed to bacteremia due to Staphylococcus cohnii ssp. urealyticus, which was grown on blood cultures originating from an infected pressure ulcer. The few cases of Staphylococcus cohnii infection reported in the literature consist of bacteremia relating to catheters, surgical prostheses, acute cholecystitis, brain abscess, endocarditis, pneumonia, urinary tract infection and septic arthritis, generally presenting a multiresistant profile, with nearly 90% resistance to methicillin. CONCLUSIONS

The reported case is, to our knowledge, the first case of true bacteremia due to Staphylococcus cohnii subsp. urealyticus caused by an infected pressure ulcer. It shows that this species may be underdiagnosed and should be considered in the differential diagnosis for community-acquired skin infections. .


CONTEXTO

Staphylococcus coagulase-negativos, colonizadores frequentes da pele humana, têm sido reconhecidos como agentes de infecções nosocomiais. RELATO DE CASO

Relata-se o caso de um paciente de 79 anos com demência vascular que apresentou síndrome da resposta inflamatória sistêmica atribuída a bacteremia por Staphylococcus cohnni ssp. urealyticus, que cresceu em hemoculturas, secundária a uma úlcera de pressão infectada. Os poucos casos de infecção por Staphylococcus cohnii relatados na literatura descrevem bacteremia associada a cateter, próteses cirúrgicas, colecistite aguda, abscesso cerebral, endocardite, pneumonia, infecção do trato urinário e artrite séptica, geralmente apresentando um perfil de multirresistência, com aproximadamente 90% de resistência à meticilina. CONCLUSÕES

O caso relatado é, ao nosso conhecimento, o primeiro de bacteremia verdadeira por Staphylococcus cohnii subsp. urealyticus causada por uma úlcera por pressão, mostrando que esta espécie pode estar subdiagnosticada e deveria ser considerada no diagnóstico diferencial das infecções cutâneas adquiridas na comunidade. .


Assuntos
Idoso , Humanos , Masculino , Bacteriemia/microbiologia , Úlcera por Pressão/complicações , Infecções Estafilocócicas , Coagulase , Infecção Hospitalar/microbiologia , Diagnóstico Diferencial , Staphylococcus/classificação , Staphylococcus/crescimento & desenvolvimento
20.
Rev. Soc. Bras. Med. Trop ; 46(1): 34-38, Jan.-Feb. 2013. graf, tab
Artigo em Inglês | LILACS | ID: lil-666791

RESUMO

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen commonly associated with nosocomial infections. However, it has also been associated with community-acquired skin and soft tissue infections (CA-MRSA). There are few data on the identification and prevalence of CA-MRSA infections in Brazil. METHODS: This is a cross-sectional study of 104 patients with community-acquired skin infections attending two health care centers in Porto Alegre, southern Brazil. MRSA isolates were characterized by molecular methods, including detection of the mecA gene by PCR, gene SCCmec typing, Panton-Valentine leukocidin (PVL) detection, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). RESULTS: From the 104 samples, 58 Staphylococcus aureus isolates were obtained, of which five (8.6%) had a CA-MRSA-resistant profile. All five isolates had the mecA gene and amplified to SCCmec type IV. Analysis of chromosomal DNA by PFGE revealed the presence of two clusters related to international clones (OSPC and USA 300), with a Dice similarity coefficient >80%. The study was complemented by MLST, which detected three different strains: ST30, ST8, and ST45, the latter not presenting any relation with the clones compared in PFGE. CONCLUSIONS: The presence of CA-MRSA reveals an important change in the epidemiology of this pathogen and adds new elements to the knowledge of the molecular biology of infections by MRSA with SCCmec type IV in southern Brazil.


Assuntos
Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Adulto Jovem , Staphylococcus aureus Resistente à Meticilina , Infecções dos Tecidos Moles/microbiologia , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Toxinas Bacterianas , Técnicas de Tipagem Bacteriana , Brasil/epidemiologia , Estudos Transversais , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , DNA Bacteriano , Eletroforese em Gel de Campo Pulsado , Exotoxinas , Leucocidinas , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções dos Tecidos Moles/epidemiologia , Infecções Estafilocócicas/epidemiologia
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