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BACKGROUND: The association between Staphylococcus haemolyticus and severe nosocomial infections is increasing. However, the extent to which fomites contribute to the dissemination of this pathogen through patients and hospital wards remains unknown. OBJECTIVES: In the present study, sphygmomanometers and thermometers were evaluated as potential fomites of oxacillin-resistant S. haemolyticus (ORSH). The influence of oxacillin and vancomycin on biofilm formation by ORSH strains isolated from fomites was also investigated. METHODS: The presence of ORSH on swabs taken from fomite surfaces in a Brazilian hospital was assessed using standard microbiological procedures. Antibiotic susceptibility profiles were determined by the disk diffusion method, and clonal distribution was assessed in pulsed-field gel electrophoresis (PFGE) assays. Minimum inhibitory concentrations (MICs) of oxacillin and vancomycin were evaluated via the broth microdilution method. Polymerase chain reaction (PCR) assays were performed to detect the mecA and icaAD genes. ORSH strains grown in media containing 1/4 MIC of vancomycin or oxacillin were investigated for slime production and biofilm formation on glass, polystyrene and polyurethane catheter surfaces. FINDINGS: ORSH strains comprising five distinct PFGE types were isolated from sphygmomanometers (n = 5) and a thermometer (n = 1) used in intensive care units and surgical wards. ORSH strains isolated from fomites showed susceptibility to only linezolid and vancomycin and were characterised as multi-drug resistant (MDR). Slime production, biofilm formation and the survival of sessile bacteria differed and were independent of the presence of the icaAD and mecA genes, PFGE type and subtype. Vancomycin and oxacillin did not inhibit biofilm formation by vancomycin-susceptible ORSH strains on abiotic surfaces, including on the catheter surface. Enhanced biofilm formation was observed in some situations. Moreover, a sub-lethal dose of vancomycin induced biofilm formation by an ORSH strain on polystyrene. MAIN CONCLUSIONS: Sphygmomanometers and thermometers are fomites for the transmission of ORSH. A sub-lethal dose of vancomycin may favor biofilm formation by ORSH on fomites and catheter surfaces.
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Antibacterianos/farmacología , Biopelículas/crecimiento & desarrollo , Fómites/microbiología , Esfigmomanometros/microbiología , Staphylococcus haemolyticus/fisiología , Termómetros/microbiología , Infección Hospitalaria/microbiología , Infección Hospitalaria/transmisión , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado , Humanos , Pruebas de Sensibilidad Microbiana , Oxacilina/farmacología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/transmisión , Staphylococcus haemolyticus/efectos de los fármacos , Staphylococcus haemolyticus/aislamiento & purificación , Vancomicina/farmacologíaRESUMEN
This study aimed to identify factors associated with colonization by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in adult patients admitted to a Brazilian hospital. This is a cross-sectional study, in which patients underwent a nasal swab and were asked about hygiene behavior, habits, and clinical history. Among the 702 patients, 180 (25.6%) had S. aureus and 21 (2.9%) MRSA. The factors associated with MRSA colonization were attending a gym (OR 4.71; 95% CI; 1.42 - 15.06), smoking habit in the last year (OR 2.37; 95% CI; 0.88 - 6.38), previous hospitalization (OR 2.18; CI 95%; 0.89 - 5.25), and shared personal hygiene items (OR 1.99; 95% CI; 0.71 - 5.55). At the time of admission, colonization by CA-MRSA isolates was higher than that found in the general population. This can be an important public health problem, already endemic in hospitals, whose factors such as those associated with habits (smoking cigarettes) and behaviors (team sports practice and activities in gyms) have been strongly highlighted. These findings may help developing infection control policies, allowing targeting patients on higher-risk populations for MRSA colonization.
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Infecciones Comunitarias Adquiridas , Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Humanos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Estudios Transversales , Masculino , Femenino , Infecciones Estafilocócicas/microbiología , Infecciones Comunitarias Adquiridas/microbiología , Persona de Mediana Edad , Adulto , Factores de Riesgo , Brasil/epidemiología , Adulto Joven , Anciano , Factores Socioeconómicos , Portador Sano/microbiología , AdolescenteRESUMEN
Methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative Staphylococcus spp (CNS) are the most common pathogens that cause serious long term infections in patients. Despite the existence of new antimicrobial agents, such as linezolid, vancomycin (VAN) remains the standard therapy for the treatment of infections caused by these multidrug-resistant strains. However, the use of VAN has been associated with a high frequency of therapeutic failures in some clinical scenarios, mainly with decreasing concentration of VAN. This work aims to evaluate the synergic potential of VAN plus sulfamethoxazole/trimethoprim (SXT), VAN plus rifampin (RIF) and VAN plus imipenem (IPM) in sub-minimum inhibitory concentrations against 22 clinical strains of MRSA and CNS. The checkerboard method showed synergism of VAN/RIF and VAN/SXT against two and three of the 22 strains, respectively. The combination of VAN with IPM showed synergistic effects against 21 out of 22 strains by the E-test method. Four strains were analyzed by the time-kill curve method and synergistic activity was observed with VAN/SXT, VAN/RIF and especially VAN/IPM in sub-inhibitory concentrations. It would be interesting to determine if synergy occurs in vivo. Evidence of in vivo synergy could lead to a reduction of the standard VAN dosage or treatment time.
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Antibacterianos/farmacología , Imipenem/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus/efectos de los fármacos , Combinación Trimetoprim y Sulfametoxazol/farmacología , Vancomicina/farmacología , Coagulasa/metabolismo , Sinergismo Farmacológico , Humanos , Pruebas de Sensibilidad Microbiana , Staphylococcus/metabolismoRESUMEN
Carbapenemase production is an important mechanism of carbapenem resistance among nonfermentative Gram-negative isolates. This study aimed to report the detection of bla(OXA-58) gene in multiresistant clinical isolates of Acinetobacter baumannii recovered from inpatients in a public hospital. Polymerase chain reaction tests were performed to detect the bla(OXA-23-like), bla(OXA-24-like), bla(OXA-58-like) and bla(OXA-51-like) genes. The bla(OXA-58) and bla(OXA-23) genes were detected in one and three isolates, respectively. Sequencing of the bla(OXA-58-like) amplicon revealed 100% identity with the A. baumannii bla(OXA-58) gene listed in the GenBank database. This is the first report of an OXA-58-producing A. baumannii isolate in Rio de Janeiro, Brazil.
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Acinetobacter baumannii/genética , beta-Lactamasas/genética , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/enzimología , Antibacterianos/farmacología , Pruebas Antimicrobianas de Difusión por Disco , Farmacorresistencia Bacteriana Múltiple , Humanos , Reacción en Cadena de la PolimerasaRESUMEN
Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3) isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.
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Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Poríferos/microbiología , Pseudomonas putida/química , Animales , Antibacterianos/biosíntesis , Antibacterianos/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Océanos y Mares , Filogenia , Pseudomonas putida/genética , Pseudomonas putida/aislamiento & purificación , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Técnica del ADN Polimorfo Amplificado AleatorioRESUMEN
INTRODUCTION: This study aimed to characterize Staphylococcus aureus isolates from bloodstream infections in patients attending a teaching hospital, between 2011 and 2015. METHODS: The minimum inhibitory concentration for daptomycin, linezolid, oxacillin, teicoplanin, vancomycin, and trimethoprim/sulfamethoxazole was accessed by broth microdilution. SCCmec type and clonal profile were determined by molecular tests. Vancomycin heteroresistance was evaluated using screening tests and by population analysis profile/area under the curve. RESULTS: Among 200 S. aureus isolates, 55 (27.5%) were MRSA, carrying SCCmec II (45.5%) or IV (54.5%). The most frequent MRSA lineages were USA100 (ST5-II) (45.5%) and USA800 (ST5-IV) (30.9%). Six isolates were confirmed as vancomycin heteroresistant, showing area under the curve ratio 1.1, 1.2 or 1.3 (four USA100, one USA800 and one USA1100 isolates). CONCLUSIONS: Daptomycin and vancomycin non-susceptible MRSA clonal lineages were found in bloodstream infections over five years, highlighting the importance of continuous surveillance of multiresistant bacteria in hospitals.
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Antibacterianos/farmacología , Bacteriemia/microbiología , Daptomicina/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Vancomicina/farmacología , Brasil , Infección Hospitalaria/microbiología , Hospitales de Enseñanza , Humanos , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/microbiologíaRESUMEN
ABSTRACT This study aimed to identify factors associated with colonization by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in adult patients admitted to a Brazilian hospital. This is a cross-sectional study, in which patients underwent a nasal swab and were asked about hygiene behavior, habits, and clinical history. Among the 702 patients, 180 (25.6%) had S. aureus and 21 (2.9%) MRSA. The factors associated with MRSA colonization were attending a gym (OR 4.71; 95% CI; 1.42 - 15.06), smoking habit in the last year (OR 2.37; 95% CI; 0.88 - 6.38), previous hospitalization (OR 2.18; CI 95%; 0.89 - 5.25), and shared personal hygiene items (OR 1.99; 95% CI; 0.71 - 5.55). At the time of admission, colonization by CA-MRSA isolates was higher than that found in the general population. This can be an important public health problem, already endemic in hospitals, whose factors such as those associated with habits (smoking cigarettes) and behaviors (team sports practice and activities in gyms) have been strongly highlighted. These findings may help developing infection control policies, allowing targeting patients on higher-risk populations for MRSA colonization.
RESUMEN
ABSTRACT The methicillin-resistant Staphylococcus aureus (MRSA) USA300-Latin American variant (USA300-LV) lineage is well documented in northern Latin American countries. It has replaced established clones in hospital environments. We herein report a systemic infection caused by a USA300-LV isolate in a 15-year-old boy, from a low-income area of Rio de Janeiro, previously colonized by the same strain. During hospital stay, seven pvl-positive MRSA USA300-LV isolates were recovered by nasal swab, blood and abscess secretion. The patient underwent intravenous vancomycin, daptomycin, and oral sulfamethoxazole/trimethoprim, and was discharged after 45 days after full recovery. This is the first documented case of a community-acquired MRSA infection caused by the USA300-LV variant in Brazil in a previously colonized adolescent with no history of recent travel outside of Rio de Janeiro. The need for improved surveillance programs to detect MRSA colonization in order to control the spread of hypervirulent lineages among community and hospital settings is highlighted.
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This study evaluated the BHIA screening method with 4 or 6 mug/mL of vancomycin to detect glycopeptides heteroresistant staphylococci strains isolated from bacteremia. A total of 213 staphylococci strains were isolated from 106 patients between October/2001 and November/2002 in a tertiary hospital in Rio de Janeiro city. Fifty-seven (53.8%) patients presented Staphylococcus aureus, while coagulase-negative staphylococci (CNS) were isolated from 49 (46.2%). Resistance rates for oxacillin of 26.3% and 81.6% were found for the staphylococci isolates, respectively. Thirteen CNS isolated from nine (8.5%) patients grew on agar screening with 4 mug/mL of vancomycin and showed heterogeneous profiles of resistance for vancomycin and teicoplanin by the population analysis profile method. Only 30.8% of them grew at the concentration 6 mug/mL. Bacterial infection and use of antimicrobial therapy were common among these patients. Alert about the emergence of oxacillin-resistant staphylococci presenting heteroresistance to glycopeptides is important in order to achieve judicious use of antimicrobials. Vancomycin agar screening test could help to confirm the presence of these isolates in hospitals.
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Antibacterianos/farmacología , Staphylococcus/efectos de los fármacos , Teicoplanina/farmacología , Vancomicina/farmacología , Anciano , Anciano de 80 o más Años , Bacteriemia/microbiología , Medios de Cultivo , Femenino , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana/métodos , Reproducibilidad de los Resultados , Infecciones Estafilocócicas/microbiología , Staphylococcus/clasificación , Staphylococcus/aislamiento & purificaciónRESUMEN
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococcus infections are a worldwide concern. Currently, these isolates have also shown resistance to vancomycin, the last therapy used in these cases. It has been observed that quinones and other related compounds exhibit antibacterial activity. This study evaluated the antibacterial activity, toxicity and in vivo dermal irritability of lapachol extracted from Tabebuia avellanedae and derivatives against methicillin-resistant staphylococcal isolates. In addition, its mechanism of action was also analyzed. METHODS: The compounds beta-lapachone, 3-hydroxy beta N lapachone and alpha-lapachone were tested to determine the MIC values against methicillin-resistant S. aureus, S. epidermidis and S. haemolyticus strains, being the two last ones hetero-resistant to vancomycin. Experiments of protein synthesis analysis to investigate the naphthoquinones action were assessed. In vitro toxicity to eukaryotic BSC-40 African Green Monkey Kidney cell cultures and in vivo primary dermal irritability in healthy rabbits were also performed. RESULTS: The compounds tested showed antibacterial activity (MICs of 8, 4/8 and 64/128 microg/mL to beta-lapachone, 3-hydroxy beta N lapachone and alpha-lapachone, respectively), but no bactericidal activity was observed (MBC > 512 microg/mL for all compounds). Although it has been observed toxic effect in eukaryotic cells, the compounds were shown to be atoxic when applied as topic preparations in healthy rabbits. No inhibition of proteins synthesis was observed. CONCLUSION: Our results suggest that quinones could be used in topic preparations against wound infections caused by staphylococci, after major investigation of the pharmacological properties of the compounds. Studies about the use of these compounds on tumoral cells could be carried on, due to their effect in eukaryotic cells metabolism.
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Irritantes/toxicidad , Naftoquinonas/farmacología , Extractos Vegetales/farmacología , Piel/patología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus haemolyticus/efectos de los fármacos , Tabebuia/química , Animales , Línea Celular , Chlorocebus aethiops , Resistencia a la Meticilina , Naftoquinonas/aislamiento & purificación , Naftoquinonas/toxicidad , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/toxicidad , Conejos , Piel/efectos de los fármacosRESUMEN
Corynebacterium diphtheriae is typically recognized as a colonizer of the upper respiratory tract (respiratory diphtheria) and the skin (cutaneous diphtheria). However, different strains of Corynebacteriumdiphtheriae can also cause invasive infections. In this study, the characterization of a non-toxigenic Corynebacteriumdiphtheriae strain (designated BR-INCA5015) isolated from osteomyelitis in the frontal bone of a patient with adenoid cystic carcinoma was performed. Pathogenic properties of the strain BR-INCA5015 were tested in a Caenorhabditis elegans survival assay showing strong colonization and killing by this strain. Survival rates of 3.8±2.7 %, 33.6±7.3 % and 0 % were observed for strains ATCC 27010T, ATCC 27012 and BR-INCA5015, respectively, at day 7. BR-INCA5015 was able to colonize epithelial cells, showing elevated capacity to adhere to and survive within HeLa cells compared to other Corynebacteriumdiphtheriae isolates. Intracellular survival in macrophages (THP-1 and RAW 264.7) was significantly higher compared to control strains ATCC 27010T (non-toxigenic) and ATCC 27012 (toxigenic). Furthermore, the ability of BR-INCA5015 to induce osteomyelitis was confirmed by in vivo assay using Swiss Webster mice.
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Corynebacterium diphtheriae/aislamiento & purificación , Corynebacterium diphtheriae/patogenicidad , Osteomielitis/microbiología , Adulto , Animales , Caenorhabditis elegans , Corynebacterium diphtheriae/clasificación , Corynebacterium diphtheriae/genética , Células Epiteliales/microbiología , Femenino , Humanos , Macrófagos/microbiología , Masculino , Ratones , Células RAW 264.7 , VirulenciaRESUMEN
Coagulase-negative Staphylococcus spp. (CNS) has been associated with primary bloodstream infections and implanted medical devices. Its importance is increasing due to the acquisition of resistance to oxacillin (Oxa) and, recently, resistance to mupirocin (Mup). Mupirocin, a topical antimicrobial, has been used in the prevention of staphylococci catheter colonization. Susceptibility to Oxa and Mup was analyzed by different testing methods in clinical CNS isolates. Among 112 CNS strains, 69 (61.6%) were Oxa(R) by the disk diffusion (DD) method and 72 (64.2%) grew on the oxacillin agar screen plate. S. epidermidis and S. haemolyticus presented high rates of oxacillin resistance, 75.4% and 96.1%, respectively. Twenty four (21.4%) strains were Mup(R) by the DD test and 21 of them (87.5%) were identified as S. epidermidis. The detection of the mecA and ileS-2 genes, determined by multiplex-PCR, showed that 72 (64.2%) CNS strains possessed the mecA gene, while 16 (14.3%) possessed the ileS-2 gene. Fifteen of these strains presented the two resistance genes simultaneously. The isolates containing the ileS-2 gene presented a minimum inhibitory concentration (MIC) >1024 microg/mL in the E-test, while low-level mupirocin resistance (MICs of 12-16 microg/mL) was observed in those strains without ileS-2. The resistances to high and low levels of mupirocin could not be distinguished when the DD test was used. The analysis of the Mup(R) S. epidermidis strains by Pulsed Field Gel Electrophoresis showed that 17 (80.9%) strains belonged to one of two patterns (A and B), which have been shown to be prevalent in hospitals in Rio de Janeiro. This report showed that the PCR method for detection of oxacillin and mupirocin resistance in CNS is necessary to determine accurate rates of these resistance, and will can help in the staphylococcal infections prevention and control policies in Brazil.
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Proteínas Bacterianas/genética , Técnicas de Tipificación Bacteriana/métodos , Coagulasa/análisis , Farmacorresistencia Bacteriana Múltiple/genética , Genes Bacterianos/genética , Staphylococcus/clasificación , Staphylococcus/genética , Brasil , ADN Bacteriano , Electroforesis en Gel de Campo Pulsado , Hospitales , Humanos , Pruebas de Sensibilidad Microbiana , Mupirocina/farmacología , Oxacilina/farmacología , Fenotipo , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , Staphylococcus/enzimología , Staphylococcus/aislamiento & purificaciónRESUMEN
ABSTRACT Introduction: This study aimed to characterize Staphylococcus aureus isolates from bloodstream infections in patients attending a teaching hospital, between 2011 and 2015. Methods: The minimum inhibitory concentration for daptomycin, linezolid, oxacillin, teicoplanin, vancomycin, and trimethoprim/sulfamethoxazole was accessed by broth microdilution. SCCmec type and clonal profile were determined by molecular tests. Vancomycin heteroresistance was evaluated using screening tests and by population analysis profile/area under the curve. Results: Among 200 S. aureus isolates, 55 (27.5%) were MRSA, carrying SCCmec II (45.5%) or IV (54.5%). The most frequent MRSA lineages were USA100 (ST5-II) (45.5%) and USA800 (ST5-IV) (30.9%). Six isolates were confirmed as vancomycin heteroresistant, showing area under the curve ratio 1.1, 1.2 or 1.3 (four USA100, one USA800 and one USA1100 isolates). Conclusions: Daptomycin and vancomycin non-susceptible MRSA clonal lineages were found in bloodstream infections over five years, highlighting the importance of continuous surveillance of multiresistant bacteria in hospitals.
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Humanos , Vancomicina/farmacología , Bacteriemia/microbiología , Daptomicina/farmacología , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Antibacterianos/farmacología , Infecciones Estafilocócicas/microbiología , Brasil , Pruebas de Sensibilidad Microbiana , Infección Hospitalaria/microbiología , Hospitales de EnseñanzaRESUMEN
OBJECTIVE: To investigate the pathogenesis of bloodstream infection by Staphylococcus epidermidis, using the molecular epidemiology, in high-risk neonates. METHODS: We conducted a prospective study of a cohort of neonates with bloodstream infection using central venous catheters for more than 24h. "National Healthcare Safety Network" surveillance was conducted. Genotyping was performed by DNA fingerprinting and mecA genes and icaAD were detected by multiplex-PCR. RESULTS: From April 2006 to April 2008, the incidence of bloodstream infection and central venous catheter-associated bloodstream infection was 15.1 and 13.0/1000 catheter days, respectively, with S. epidermidis accounting for 42.9% of episodes. Molecular analysis was used to document the similarity among six isolates of bloodstream infection by S. epidermidis from cases with positive blood and central venous catheter tip cultures. Fifty percent of neonates had bloodstream infection not identified as definite or probable central venous catheter-related bloodstream infection. Only one case was considered as definite central venous catheter-related bloodstream infection and was extraluminally acquired; the remaining were considered probable central venous catheter-related bloodstream infections, with one probable extraluminally and another probable intraluminally acquired bloodstream infection. Additionally, among mecA+ and icaAD+ samples, one clone (A) was predominant (80%). A polyclonal profile was found among sensitive samples that were not carriers of the icaAD gene. CONCLUSIONS: The majority of infections caused by S. epidermidis in neonates had an unknown origin, although 33.3% appeared to have been acquired intraluminally and extraluminally. We observed a polyclonal profile between sensitive samples and a prevalent clone (A) between resistant samples.
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Bacteriemia/microbiología , Infecciones Relacionadas con Catéteres/microbiología , Cateterismo Venoso Central/efectos adversos , Infección Hospitalaria/microbiología , Infecciones Estafilocócicas/microbiología , Staphylococcus epidermidis/genética , Estudios de Cohortes , Dermatoglifia del ADN , ADN Bacteriano/análisis , Electroforesis en Gel de Campo Pulsado , Genotipo , Humanos , Recién Nacido , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Staphylococcus epidermidis/aislamiento & purificaciónRESUMEN
Staphylococcus aureus is an important cause of infections and HIV-infected individuals are frequently susceptible to this pathogen. The aim of this study was to perform a systematic review to identify both the risk factors associated with colonization/infection by methicillin-resistant S. aureus in HIV patients and the methods used for characterization of isolates. An electronic search of articles published between January 2001 and December 2013 was first conducted. Among 116 studies categorized as being at a quality level of A, B or C, only 9 studies were considered to have high methodological quality (level A). The majority of these studies were retrospective (4/9 studies). The risk factors associated with colonization/infection by S. aureus were use of antimicrobials (4/9 studies), previous hospitalization (4/9 studies) and low CD4+ T lymphocyte counts (<200 cells/µl) (3/9 studies). Culture in mannitol salt agar (3/9 studies) and the latex agglutination test (5/9 studies) were the main methods used for bacterial phenotypic identification. Genotypic profiles were accessed by pulsed-field gel electrophoresis (6/9 studies) and USA300 was the most prevalent lineage (5/9 studies). Most isolates were resistant to erythromycin (3/9 studies) and susceptible to vancomycin (4/9 studies). Ultimately, use of antimicrobials and previous hospitalization were the main risk factors for colonization/infection by methicillin-resistant S. aureus in HIV-infected individuals. However, the numbers of evaluated patients, the exclusion and inclusion criteria and the characterization of the S. aureus isolates were not uniform, which made it difficult to establish the characteristics associated with HIV patients who are colonized/infected by S. aureus.
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Infecciones por VIH/microbiología , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/microbiología , Antibacterianos/uso terapéutico , Humanos , Resistencia a la Meticilina , Staphylococcus aureus Resistente a Meticilina/crecimiento & desarrollo , Factores de RiesgoRESUMEN
INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) can be difficult to detect at the clinical practice. METHODS: We analyzed 140 MRSA isolates from inpatients to correlate the antimicrobial susceptibility with the SCCmec types. RESULTS: Type III (n = 63) isolates were more resistant to ciprofloxacin, clindamycin, cloramphenicol, erythromycin, gentamicin, and rifampin than type IV (n = 65) ones (p < 0.05). Moreover, type IV isolates were susceptible to tetracycline (100%) and trimethoprim/sulfamethoxazole (98%), while type III isolates presented resistance to them. CONCLUSIONS: In regions where these SCCmec types are prevalent, the detection of specific resistant phenotypes could help to predict them, mainly when there are no technical conditions to SCCmec typing.
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Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Staphylococcus aureus Resistente a Meticilina/genética , Tetraciclina/farmacología , Combinación Trimetoprim y Sulfametoxazol/farmacología , Cromosomas Bacterianos/genética , ADN Bacteriano/genética , Genotipo , Humanos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Pruebas de Sensibilidad Microbiana/métodos , FenotipoRESUMEN
Abstract Staphylococcus aureus is an important cause of bloodstream infections. Therefore, the main purpose of this work was to characterize a collection of 139 S. aureus isolates from bloodstream infections in two public hospitals in relation to their antimicrobial susceptibility profile, staphylococcal cassette chromosome mec types, and clonal relationship. Methicillin resistance and resistance to other 12 agents were accessed by the disk diffusion test. Minimum inhibitory concentration to mupirocin was also determined. The SCCmec types were accessed by multiplex PCR, and the clonal relationship was determined by pulsed field gel electrophoresis method and restriction modification system characterization. Besides, multilocus sequence typing was performed for representative methicillin-resistant S. aureus isolates. The military hospital showed a dissemination of the New York/Japan (USA100/ST5/CC5/SCCmecII) lineage associated to multidrug resistance, including mupirocin resistance, and the teaching hospital presented polyclonal and non-multidrug resistant MRSA isolates. Complete substitution of the Brazilian endemic clone by other lineages was found in both hospitals. These findings can highlight differences in policy control and prevention of infections used in the hospitals and a change in the epidemiological profile of MRSA in Brazilian hospitals, with the replacement of BEC, a previously well-established clone, by other lineages.
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Humanos , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Antibacterianos/farmacología , Brasil , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Mupirocina/farmacología , Electroforesis en Gel de Campo Pulsado , Pruebas Antimicrobianas de Difusión por Disco , Staphylococcus aureus Resistente a Meticilina/genética , Tipificación de Secuencias Multilocus , Genotipo , Hospitales PúblicosRESUMEN
BACKGROUND The association between Staphylococcus haemolyticus and severe nosocomial infections is increasing. However, the extent to which fomites contribute to the dissemination of this pathogen through patients and hospital wards remains unknown. OBJECTIVES In the present study, sphygmomanometers and thermometers were evaluated as potential fomites of oxacillin-resistant S. haemolyticus (ORSH). The influence of oxacillin and vancomycin on biofilm formation by ORSH strains isolated from fomites was also investigated. METHODS The presence of ORSH on swabs taken from fomite surfaces in a Brazilian hospital was assessed using standard microbiological procedures. Antibiotic susceptibility profiles were determined by the disk diffusion method, and clonal distribution was assessed in pulsed-field gel electrophoresis (PFGE) assays. Minimum inhibitory concentrations (MICs) of oxacillin and vancomycin were evaluated via the broth microdilution method. Polymerase chain reaction (PCR) assays were performed to detect the mecA and icaAD genes. ORSH strains grown in media containing 1/4 MIC of vancomycin or oxacillin were investigated for slime production and biofilm formation on glass, polystyrene and polyurethane catheter surfaces. FINDINGS ORSH strains comprising five distinct PFGE types were isolated from sphygmomanometers (n = 5) and a thermometer (n = 1) used in intensive care units and surgical wards. ORSH strains isolated from fomites showed susceptibility to only linezolid and vancomycin and were characterised as multi-drug resistant (MDR). Slime production, biofilm formation and the survival of sessile bacteria differed and were independent of the presence of the icaAD and mecA genes, PFGE type and subtype. Vancomycin and oxacillin did not inhibit biofilm formation by vancomycin-susceptible ORSH strains on abiotic surfaces, including on the catheter surface. Enhanced biofilm formation was observed in some situations. Moreover, a sub-lethal dose of vancomycin induced biofilm formation by an ORSH strain on polystyrene. MAIN CONCLUSIONS Sphygmomanometers and thermometers are fomites for the transmission of ORSH. A sub-lethal dose of vancomycin may favor biofilm formation by ORSH on fomites and catheter surfaces.
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Humanos , Oxacilina/farmacología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/transmisión , Termómetros/microbiología , Vancomicina/farmacología , Infección Hospitalaria/microbiología , Biopelículas/crecimiento & desarrollo , Esfigmomanometros/microbiología , Staphylococcus haemolyticus/aislamiento & purificación , Staphylococcus haemolyticus/efectos de los fármacos , Staphylococcus haemolyticus/fisiología , Antibacterianos/farmacología , Resistencia a Medicamentos , Pruebas de Sensibilidad Microbiana , Infección Hospitalaria/transmisión , Electroforesis en Gel de Campo Pulsado , ElectroforesisRESUMEN
Staphylococcus lugdunensis is a rare cause of severe infections and clinical manifestations are similar to those related to S. aureus infection. We describe a hospital-acquired bacteremia due to methicillin-resistant Staphylococcus lugdunensis, misidentified as methicillin-resistant S. aureus. The oxacillin MIC was 16 µg/mL and the mecA gene and SCCmec type V were determined by PCR. Although treatment had been appropriated, the patient died after rapid progressive respiratory failure and another nosocomial sepsis. It is important not only to identify S. lugdunensis in view of its clinical course, but also to determine its susceptibility to oxacillin by detecting the mecA gene or its product.
Asunto(s)
Bacteriemia/microbiología , Infección Hospitalaria/microbiología , Resistencia a la Meticilina/genética , Infecciones Estafilocócicas/microbiología , Staphylococcus lugdunensis/genética , Anciano , Antibacterianos/farmacología , Bacteriemia/diagnóstico , Proteínas Bacterianas/genética , Infección Hospitalaria/diagnóstico , Femenino , Humanos , Resistencia a la Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina , Oxacilina/farmacología , Infecciones Estafilocócicas/diagnóstico , Staphylococcus lugdunensis/efectos de los fármacosRESUMEN
Herpes simplex virus types 1 and 2 are the main infectious agents associated with oral and genital ulcerations. These infections are now widely recognized as sexually transmitted diseases. Among treatment options, low-level laser therapy (LLLT) has shown promising clinical results as a longer-lasting suppression therapy. Two clinical cases are described with recurrent labial herpes for which LLLT was used. Following treatment, both patients remained symptom free during the 17-month clinical follow-up period.