Influencia de la edad y el género en los fenotipos y coeficientes de lateralidad en niños de 6 a 15 años

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M. Carmen Mayolas Pi

2015-06-01

Full Text Available Este estudio valora la lateralidad manual, podal y ocular de 798 niños de 6 a 15 años. Se obtienen los fenotipos de lateralidad de cada niño (homogéneo, cruzado o no definido y se comparan los resultados según el género y la edad (de 6-7 años, de 8-10 y de 11-15 años. Finalmente, se correlacionan las pruebas comparan y los coeficientes de lateralidad. Según nuestro estudio, el género no influye en la lateralidad del miembro superior, pero sí en el miembro inferior y en el ocular. La lateralidad manual se afianza entre los 8-10 años, la podal no se afianza a estas edades y la ocular tiende a la dextralidad en las chicas hasta los 15 años, pero se afianza en los chicos a los 8-10 años. Según los fenotipos de lateralidad se observa la influencia de la edad, con un aumento significativo de lateralidad homogénea a costa de una disminución de lateralidad cruzada en las edades evaluadas, pero no del género. Las correlaciones entre los tres coeficientes de lateralidad son bajas.

One-year mortality in coagulase-negative Staphylococcus and Staphylococcus aureus infective endocarditis

DEFF Research Database (Denmark)

Rasmussen, Rasmus V; Snygg-Martin, Ulrika; Olaison, Lars

2009-01-01

The aim of this study was to investigate in-hospital mortality and 12-month mortality in patients with coagulase-negative Staphylococcus (CoNS) compared to Staphylococcus aureus (S. aureus) infective endocarditis (IE). We used a prospective cohort study of 66 consecutive CoNS and 170 S. aureus IE...

Estimación de riesgo de cáncer gástrico en pacientes con gastritis crónica asociada a la infección por Helicobacter pylori en un escenario clínico

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G. Arismendi-Morillo

2013-07-01

Conclusiones: El riesgo estimado de cáncer gástrico en pacientes con GCAHpI en el entorno clínico estudiado fue relativamente bajo y 5% de los pacientes tenían un fenotipo histopatológico asociado con un riesgo elevado de desarrollar cáncer gástrico.

Expresión de IL-10, IL-4 e IFN-γ en lesiones activas de piel en niños con urticaria papular por picadura de pulga

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Elizabeth García

2011-06-01

Conclusiones. Los datos corresponden a la primera descripción de citocinas que median la respuesta inmunitaria en el sitio de la lesión cutánea en niños con con urticaria papular por picadura de pulga, lo cual indica que la respuesta local es mixta ya que no se encuentra predominio de un fenotipo específico en ninguno de los pacientes.

Aislamientos de Staphylococcus aureus sensibles a meticilina relacionados genéticamente con el clon USA300, ¿origen de los aislamientos SARM de genotipo comunitario en Colombia?

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Javier Antonio Escobar-Pérez

2014-04-01

Full Text Available Introducción. USA300 es un linaje genético que se encuentra en aislamientos de Staphylococcus aureus sensibles (SASM y resistentes a meticilina (SARM. Actualmente, en Colombia las infecciones por SARM en hospitales y en la comunidad son causadas principalmente por un clon con genotipo comunitario (SARM-GC relacionado genéticamente con el clon USA300. El origen de esta variante es aún desconocido. Objetivo. Identificar y caracterizar aislamientos de S. aureus resistentes y sensibles a meticilina con el fin de aportar información para establecer un posible origen de los aislamientos SARM-GC en Colombia. Materiales y métodos. Se realizó una caracterización de aislamientos SASM relacionados con el clon USA300 detectados a partir de un análisis de 184 aislamientos de S. aureus (90 SARM y 94 SASM causantes de infecciones. La relación genética de los aislamientos se determinó por electroforesis en gel de campo pulsado (PFGE, tipificación de secuencias multilocus (MLST y tipificación del gen de la proteína A (spa. Resultados. De los 184 aislamientos, 27 (14,7 % presentaron características moleculares y relación genética con el clon USA300, y de ellos, 18 fueron SARM y nueve fueron SASM. Todos los aislamientos SARM relacionados con este clon albergaban un casete estafilocócico cromosómico mec (SCCmec IVc (3.1.2. En ningún aislamiento SASM se detectaron secuencias remanentes de SCCmec o una duplicación del sitio attB que evidenciaran la pérdida del casete. Conclusión. El origen de los aislamientos SARM-GC en Colombia probablemente se encuentre en la diseminación de clones SASM relacionados con el clon USA300 que adquirieron el SCCmec IVc posteriormente.

Frecuencia y tipos de toxinas superantígenos en Staphylococcus aureus de diferentes orígenes: relaciones con tipos genéticos

OpenAIRE

Fueyo Mendoza, José María

2005-01-01

Staphylococcus aureus de diferentes orígenes (muestras nasales de portadores humanos, alimentos manipulados, y leche de vacas con mastitis subclínica), recogidos en Asturias (1996-2002), han sido analizados mediante técnicas convencionales y moleculares para determinar la frecuencia y los tipos de genes de toxinas pirogénicas superantígenos (PTSAg) que portan y el polimorfismo de su ADN con objeto de establecer relaciones toxigénicas y genómicas entre aislamientos. La interrelación de los res...

FRECUENCIA DE GRUPOS SANGUÍNEOS (SISTEMA ABO ENTRE ESTUDIANTES DE LA UNIVERSIDAD DE CÓRDOBA SEDE BERÁSTEGUI

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Luis Causil -Vargas

2016-07-01

Full Text Available Objetivo: El objetivo del estudio fue determinar la frecuencia y distribución de grupos sanguíneos ABO y factor Rh en los estudiantes en la Universidad de Córdo­ba, Colombia, sede Berástegui. Metodología: Mediante la realización de un estudio descriptivo, transversal, en una población total de 1.112, de la cual se obtuvo una muestra de 127 personas entre las edades de 17-27 años. Resultados: Los resultados mostraron que el fenotipo A es el fenotipo más común con 51,18%, seguido de tipo fenotipo O con 37%, B con el 8,66% y AB con 3, 14%. Un total de 91,33%, voluntarios son Rh positivo, mientras que el resto son Rh negativo. Conclusión: El grupo sanguíneo A y factor Rh positivo son dominantes en ambos sexos. Palabras claves: Grupo Sanguí¬neo, factor Rh, sistema ABO, fenotipo.

Silver nanoparticles for the inhibition of Staphylococcus aureus

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Miguel Ángel Ortiz-Gila

2015-01-01

Full Text Available Existe un gran ecosistema microbiano en la cavidad oral donde Staphylococcus aureus ( S. aureus se puede encontrar, causando patologías orales tales como quelitis angular, las paperas y la mucositis estafilocócica. Estas enfermedades producidas por S. aureus en la cavidad oral son consecuencia de los factores de virulencia, toxinas y multiresistencia a los antibióticos, lo que contribuye a la infección. La colonización en la cavidad oral por S. aureus en pacientes sanos es de 24% a 36%. Sin embargo, la incidencia aumenta a 48% en pacientes con prótesis debido a la formación de biofilms en la superficie de las dentaduras postizas. Actualmente, no existe ningún tratamiento para infecciones orales sin el uso de antibióticos. Investigaciones recientes indican que las nanopartículas de plata (AgNPs son un material o estrategia para eliminar S. aureus debido a su efecto antibacteriano. Sin embargo, el mecanismo del efecto inhibidor de los iones de Ag sobre S. aureus es sólo parcialmente conocida y muy poco se ha informado. Por lo tanto, el propósito de la presente revisión sistemática es determinar las estrategias y retos de la utilización de biomateriales antimicrobianos con AgNPs frente a las infecciones orales de S. aureus.

Factores de virulencia de Staphylococcus aureus asociados con infecciones mamarias en bovinos: relevancia y rol como agentes inmunógenos

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Cecilia M Camussone

Full Text Available Staphylococcus aureus es el microorganismo causante de mastitis bovina más prevalente en Argentina y en el mundo. La falta de efectividad frente a este organismo de los métodos tradicionales de control, basados en la higiene y la terapia antibiótica, ha conducido a la búsqueda de alternativas para prevenir la enfermedad. Una de ellas es la manipulación de los mecanismos defensivos del huésped mediante vacunación. La identificación de los factores de virulencia que estimulan las defensas del huésped es fundamental para el desarrollo racional de inmunógenos.S. aureus posee múltiples factores de virulencia que interactúan con el huésped en distintas etapas de la infección mamaria; algunos de ellos han mostrado capacidad de generar una respuesta inmune benéfica para el huésped. El objetivo de este artículo es revisar conceptos de estructura, función y utilización como inmunógenos de los factores de virulencia de S. aureus considerados como más relevantes en las principales etapas de la infección intramamaria.

Inmunofenotipos aberrantes en leucemias agudas en una población hospitalaria de Buenos Aires

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Viviana Novoa

2013-02-01

Full Text Available La citometría de flujo multiparamétrica es el método de elección para la caracterización inmunofenotípica de las células hematopoyéticas clonales presentes en los distintos procesos leucémicos agudos. El objetivo fue analizar la expresión de antígenos de membrana y evaluar la presencia de fenotipos aberrantes en los blastos de pacientes con diagnóstico de leucemia aguda, que permiten el monitoreo de la respuesta al tratamiento. Se revisaron los inmunofenotipos de 364 muestras de pacientes adultos derivadas a nuestro laboratorio en un período de 7 años. El inmunofenotipo se realizó por citometría de flujo con un amplio panel de anticuerpos monoclonales con el que se evaluó la expresión de antígenos de linaje linfoide, mieloide y también antígenos de maduración. De las 364 muestras estudiadas, 60.2% presentaron un fenotipo compatible con leucemia mieloide aguda (LMA, 28.8% con leucemia linfoblástica B (LLA-B, 6.6% con leucemia linfoblástica T (LLA-T y 4.4% con leucemias agudas poco frecuentes. La presencia de fenotipos aberrantes se observó en 89% de los casos, los fenotipos aberrantes identificados fueron: 1 infidelidad de linaje: LMA (54%, LLA-B (40%, LLA-T (29%; 2 ausencia de expresión antigénica: LMA (21%, LLA-B (35%, LLA-T (70%; 3 alteración de la expresión antigénica: LMA (67%, LLA-B (66%, LLA-T (84%; 4 asincronismo madurativo: LMA (26%, LLA-B (37% y 5 fenotipo ectópico: LLA-T 96%. El análisis por citometría de flujo multiparamétrica de las leucemias agudas permitió la identificación de fenotipos aberrantes en la mayoría de nuestros pacientes, que son de utilidad para el monitoreo de la respuesta al tratamiento.

Antimicrobials from human skin commensal bacteria protect against Staphylococcus aureus and are deficient in atopic dermatitis

Science.gov (United States)

Nakatsuji, Teruaki; Chen, Tiffany H.; Narala, Saisindhu; Chun, Kimberly A.; Two, Aimee M.; Yun, Tong; Shafiq, Faiza; Kotol, Paul F.; Bouslimani, Amina; Melnik, Alexey V.; Latif, Haythem; Kim, Ji-Nu; Lockhart, Alexandre; Artis, Keli; David, Gloria; Taylor, Patricia; Streib, Joanne; Dorrestein, Pieter C.; Grier, Alex; Gill, Steven R.; Zengler, Karsten; Hata, Tissa R.; Leung, Donald Y. M.; Gallo, Richard L.

2017-01-01

The microbiome can promote or disrupt human health by influencing both adaptive and innate immune functions. We tested whether bacteria that normally reside on human skin participate in host defense by killing Staphylococcus aureus, a pathogen commonly found in patients with atopic dermatitis (AD) and an important factor that exacerbates this disease. High-throughput screening for antimicrobial activity against S.aureus was performed on isolates of coagulase-negative Staphylococcus (CoNS) collected from the skin of healthy and AD subjects. CoNS strains with antimicrobial activity were common on the normal population but rare on AD subjects. A low frequency of strains with antimicrobial activity correlated with colonization by S.aureus. The antimicrobial activity was identified as previously unknown antimicrobial peptides (AMPs) produced by CoNS species including Staphylococcus epidermidis and Staphylococcus hominis. These AMPs were strain-specific, highly potent, selectively killed S.aureus, and synergized with the human AMP LL-37. Application of these CoNS strains to mice confirmed their defense function in vivo relative to application of nonactive strains. Strikingly, reintroduction of antimicrobial CoNS strains to human subjects with AD decreased colonization by S.aureus. These findings show how commensal skin bacteria protect against pathogens and demonstrate how dysbiosis of the skin microbiome can lead to disease. PMID:28228596

Staphylococcus aureus resistente a vancomicina.

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Carlos Andrés Rodríguez

2005-12-01

Full Text Available Objetivo. Revisar la evolución y mecanismos moleculares de la resistencia de Staphylococcus aureus a vancomicina. Fuente de los datos. Se consultó la base de datos MEDLINE y se seleccionaron artículos tipo reportes de caso, estudios bioquímicos, de microscopía electrónica y biología molecular pertinentes. Síntesis. Después de casi 40 años de eficacia ininterrumpida de la vancomicina, en 1997 se reportaron los primeros casos de fracaso terapéutico debido a cepas de Staphylococcus aureus con resistencia intermedia, denominadas VISA (concentración inhibitoria mínima, CIM, 8 a 16 ?g/ml, así como a cepas con resistencia heterogénea hVISA (CIM global = 4 ?g/ml, pero con subpoblaciones VISA, en las cuales la resistencia está mediada por engrosamiento de la pared celular y disminución de su entrecruzamiento, lo que afecta la llegada del antibiótico al blanco principal, los monómeros del peptidoglicano en la membrana plasmática. En 2002 se aisló la primera de las 3 cepas reportadas hasta la fecha con resistencia total al antibiótico, denominadas VRSA (CIM>32 ?g/ml, en las que se encontró el transposón Tn1546 proveniente de Enterococcus spp, responsable del reemplazo de la terminación D-Ala-D-Ala por D-Ala-Dlactato en los precursores de la pared celular con pérdida de la afinidad por el glicopéptido. Conclusiones. La resistencia a vancomicina es una realidad en S. aureus, mediada en el caso de VISA por alteraciones en la pared celular que atrapan el antibiótico antes de llegar al sitio de acción, y en el caso de VRSA, por transferencia desde Enterococcus spp. de genes que llevan a la modificación del blanco molecular.

Enfoque terapéutico de la bacteriemia por Staphylococcus aureus

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Diego Tibavizco

2007-06-01

Full Text Available Staphylococcus aureus es un patógeno importante que causa cerca de 11% a 33% de las bacteriemias hospitalarias y un porcentaje importante de las adquiridas en la comunidad, con una tasa de complicaciones cercana a 50%. En la siguiente revisión se destaca la epidemiología de la bacteriemia por S. aureus, con especial referencia a la situación de este patógeno en Colombia, la frecuencia y los mecanismos de resistencia a los medicamentos más frecuentemente usados en este contexto, y se discuten los elementos semiológicos, clínicos y de laboratorio que influyen en el enfoque diagnóstico y terapéutico de los pacientes con bacteriemia por este microorganismo.

Cultivo in vitro del tomate de árbol (Cyphomandra betacea (Cav.) Sendt. (Fenotipo naranja) proveniente de Costa Rica

OpenAIRE

Chacón-Cerdas, Randall; Instituto Tecnológico de Costa Rica; Flores-Mora, Dora; Instituto Tecnológico de Costa Rica; Alvarado-Marchena, Luis; Instituto Tecnológico de Costa Rica; Schmidt-Durán, Alexander; Instituto Tecnológico de Costa Rica; Alvarado-Ulloa, Carlos; Instituto Tecnológico de Costa Rica

2014-01-01

El tomate de árbol (Cyphomandra betacea) es un frutal de importancia comercial en países como Bolivia, Colombia, Ecuador y Perú, donde se consume como fruta fresca y procesada. Tradicionalmente, es propagado por semillas y estacas, y enfrenta problemas de heterogeneidad y calidad de material de siembra. En esta investigación se desarrolló un protocolo para la micropropagación in vitro del tomate de árbol criollo del fenotipo naranja, proveniente de Costa Rica, el cual presenta potencial para ...

Cultivo in vitro del tomate de árbol (Cyphomandra betacea (Cav.) Sendt. (Fenotipo naranja) proveniente de Costa Rica

OpenAIRE

Randall Chacón-Cerdas; Dora Flores-Mora; Luis Alvarado-Marchena; Alexander Schmidt-Durán; Carlos Alvarado-Ulloa

2014-01-01

El tomate de árbol (Cyphomandra betacea) es un frutal de importancia comercial en países como Bolivia, Colombia, Ecuador y Perú, donde se consume como fruta fresca y procesada. Tradicionalmente, es propagado por semillas y estacas, y enfrenta problemas de heterogeneidad y calidad de material de siembra.  En esta investigación se desarrolló un protocolo para la micropropagación in vitro del tomate de árbol criollo del fenotipo naranja, proveniente de Costa Rica, el cual presenta potencial p...

Las células dendríticas generadas en presencia de vitamina D3 y activadas con lipopolisacáridos incrementan la producción de IL-1β, IL-8 e IL-10 y disminuyen su capacidad de inducir LT CD4+CD25hiFoxp3+

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Sindy M. Muñoz

2016-06-01

Conclusión. Las células dendríticas generadas con vitamina D3 y tratadas con lipopolisacáridos presentaron un fenotipo ‘semimaduro’, así como la capacidad de secretar citocinas antiinflamatorias y citocinas promotoras de la reacción inflamatoria. Además, no se aumentó su capacidad de promover la polarización de LTCD4+ vírgenes alogénicos hacia LTreg.

Identificación de mutaciones y diagnóstico molecular de portadoras en familias mexicanas con distrofia muscular Duchenne/Becker

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S. Canizales

2008-01-01

Discusión o Conclusión: El porcentaje de eliminaciones genéticas en los pacientes estudiados fue menor al reportado en otras poblaciones. Un estudio con un mayor número de individuos permitirá saber sí esta baja frecuencia es característica de nuestra población. El uso de estudios de ligamiento genético y de RT-PCR aumenta la posibilidad de definir el estado portador en mujeres pertenecientes a familias con DMD/BMD y así poder ofrecerles un adecuado consejo genético. Este es el primer trabajo realizado en México, donde se usó el RT-PCR como herramienta diagnóstica en esta distrofia, se identificó por primera vez, a nivel molecular, un paciente con Síndrome de genes continuos y se demostró un empalme alternativo en un paciente con esta miopatía para explicar su fenotipo.

Enfermedad invasora por Staphylococcus aureus meticilino resistente adquirida en la comunidad Community-acquired methicillin-resistant Staphylococcus aureus disseminated disease

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Clarisa Brezzo

2006-10-01

Full Text Available Se presenta un caso de enfermedad invasora por Staphylococcus aureus meticilino resistente (SAMR adquirido en la comunidad (SAMR-c. Paciente varón de 21 años, previamente sano, que consultó por nódulos subcutáneos compatibles con gomas. La ultrasonografía reveló múltiples abscesos subcutáneos e imágenes consistentes con piomiositis, además de derrame pleural y pericárdico. En el cultivo del material purulento obtenido por punción-aspiración con aguja fina de las lesiones se aisló S. aureus. El antibiograma por difusión mostró resistencia a cefalotina, eritromicina y clindamicina, y sensibilidad a trimetroprima-sulfametoxazol, ciprofloxacina y rifampicina. La meticilino resistencia se confirmó por aglutinación con partículas de látex sensibilizadas con anticuerpos monoclonales dirigidos contra la proteína ligadora de penicilina 2A. El paciente fue tratado con ciprofloxacina y rifampicina durante cuatro semanas, con evolución favorable. La frecuencia de infecciones por SAMR-c está en aumento, observándose en personas sin factores de riesgo aparentes. Esto llevaría a fracaso en el tratamiento empírico para infecciones de la comunidad en los que se presume etiología estafilocócica.A 21 year old man, previously healthy, presented with subcutaneous nodes consistent with gummas. Ultrasonography disclosed multiple subcutaneous abscesses and images suitable with piomiositis, pleural and pericardium effusion. A puncture-aspirate with fine-needle was performed and produced purulent material, with isolate of Staphylococcus aureus. Antimicrobial susceptibility testing by disk diffusion showed resistant to cefalotin, erythromycin and clindamycin, and susceptibility to trimethoprim-sulfamethoxazole, ciprofloxacin and rifampicin. Methicilin-resistance was confirmed by Staphyslide agglutination testing (Biomérieux. The patient was treated with ciprofloxacin and rifampicin during four weeks, with a good clinical response. The

Presentación atípica de piomiositis tropical difusa de psoas por Staphylococcus aureus meticilino resistente Atypical presentation of diffuse tropical pyomiositis of the psoas due to methicillin resistant Staphylococcus aureus

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Ray Ticse

2012-03-01

Full Text Available La piomiositis tropical difusa primaria es una enfermedad de presentación infrecuente en nuestro medio, con pocos casos asociados a Staphylococcus aureus meticilino resistente, adquirido en la comunidad (MRSA-AC. Se presenta el caso de un paciente de 70 años, con tratamiento irregular para diabetes mellitus tipo 2, que fue hospitalizado por presentar un cuadro de diez días de evolución, con dolor lumbar irradiado a miembro inferior izquierdo, fiebre y flexión forzada de la cadera derecha por dolor a la movilización. El diagnóstico de piomiositis difusa de ambos psoas se realizó con resonancia magnética. Del cultivo de una colección paravertebral posterior se aisló Staphylococcus aureus resistente a oxacilina, penicilina y dicloxacilina.Diffuse tropical primary pyomyositis is an infrequent entity in our country, with few cases associated to communityacquired Methicillin- resistant Staphylococcus aureus. There are no reported cases of Community-Acquired Methicillin- Resistant Staphylococcus aureus (CA- MRSA in Peru. We present the case of a 70 year old male with a previous diagnosis of type 2 diabetes mellitus, receiving irregular treatment, who was admitted to the hospital with a history of 10 days of low back pain radiating to the left leg, fever and forced flexion of the right hip due to pain during movement. The diagnosis of diffuse pyomyositis of both psoas muscles was performed with MRI and culture of a posterior paravertebral collection, from which Staphylococcus aureus resistant to oxacillin, penicillin and dicloxacillin was isolated.

Identificación de biotipos de Staphyloccocus aureus en vacas lecheras de producción familiar con mastitis subclínica en la región centro-este del Estado de México

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Ana María Manjarrez López

2012-01-01

Full Text Available La mastitis ocasiona grandes pérdidas económicas en los hatos lecheros. El Staphylococcus aureus es uno de los principales agentes causales de la enfermedad, considerado de importancia en la salud pública y la salud del hato. El objetivo del estudio fue determinar la frecuencia de S. aureus y los biotipos predominantes en vacas con mastitis subclínica en hatos de producción lechera familiar en la región económica I, Centro-Este del Estado de México. Se condujo un estudio trasversal, en 269 vacas de diferentes etapas de lactación e información del hato en una encuesta cerrada. La muestra de leche se recolectó de cada vaca. La detección de mastitis se realizó mediante la prueba de California. Los biotipos de S. aureus se caracterizaron por medio de la técnica de agar tripticasa soya adicionado con cristal violeta 1:100,000. En las vacas estudiadas la prevalencia de mastitis subclínica fue del 48.3 % (IC95% 42.22 a 54.47 y de mastitis clínica 6.1 % (IC95% 3.44 a 9.48. Se obtuvieron 62 aislamientos de S. aureus, el 79 % correspondió al biotipo C (humano, el 11.3 % al A (bovino, el 6.5 % al E (canino y el 3.2 % a hospederos no específicos. El tamaño del hato resultó un factor de riesgo asociado a la mayor frecuencia de S. aureus, especialmente cuando el hato fue mayor de 13 vacas (OR=5.63, IC95% 1.72 a 18.21. Se identifico una prevalencia elevada de mastitis subclínica asociada a la infección por S. aureus Biotipos C y A considerados de importancia en la salud pública.

Mortality among critically ill patients with methicillin-resistant Staphylococcus aureus bacteremia: a multicenter cohort study in Colombia Mortalidad en pacientes gravemente enfermos con bacteriemia por Staphylococcus aureus resistente a la meticilina: un estudio multicéntrico de cohortes en Colombia

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Juan S. Castillo

2012-11-01

Full Text Available OBJECTIVE: To evaluate risk factors associated with methicillin-resistant Staphylococcus aureus (MRSA bacteremia emergence, its prognosis, and mortality-determining factors in critically ill patients in Colombia. METHODS: A multicenter, retrospective cohort study conducted in 2005-2008 at 16 public and private reference health care institutions in Bogotá, Colombia, that form part of a national epidemiological surveillance network and a hospital network with 4 469 beds. Methicillin-resistant emergence and mortality were analyzed using descriptive and time-to-event analysis; a multivariate Cox proportional hazard regression model was built to test the association between methicillin resistance and mortality. RESULTS: A total of 372 patients were studied: 186 with MRSA bacteremia, randomly matched with 186 with methicillin-susceptible Staphylococcus aureus (MSSA bacteremia. Previous surgery, antibiotic exposure, and hospital-acquired infections were independently associated with methicillin resistance. MRSA caused longer hospital stays among survivors (median 24 versus 18 days, P = 0.014. Mortality predictors were: patient age, creatinine level over 1.21mg/dl at ICU admission, severe sepsis, and inotropic requirement. Appropriate antimicrobial therapy and antimicrobial therapy change were independent protective factors, as was male gender. CONCLUSIONS: Methicillin resistance per se was not a mortality-independent prognostic factor. Previous conditions, such as age, baseline renal impairment, severe sepsis, and inotropy demand explained the observed mortality. Appropriate antimicrobial therapy remained a protective factor. A call to improve infection control measures in Colombia is mandatory.OBJETIVO: Evaluar los factores de riesgo asociados con la aparición de bacteriemia por Staphylococcus aureus resistente a la meticilina (MRSA, su pronóstico y los factores determinantes de la mortalidad en pacientes gravemente enfermos en Colombia. M�

CARACTERIZACIÓN BIOLÓGICA DE VARIANTES DE PLACA DE LA CEPA VACUNAL 17D CONTRA LA FIEBRE AMARILLA

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María Rojas

2009-09-01

Full Text Available La vacuna colombiana 17D, contiene por lo menos cuatro fenotipos, denominados pequeño (0.3 – 1.2 mm, mediano (1.3 – 2.1 mm, grande (2.2 – 3.0 mm y extragrande (>3.1 mm. La composición y distribución porcentual de esos fenotipos, varió entre lotes y entre ampolletas de un mismo lote. Cada variante fue clonada por dilución de la vacuna y su efecto virulento fue analizado en ratones; el fenotipo de placa pequeño estuvo ligeramente sub representado en los lotes analizados y mostró una virulencia similar a la de la cepa silvestre neurotrópica Francesa (LD50 > 10-6, mientras que el fenotipo predominante y mas atenuado fue el mediano (LD50: 10-4. Los fenotipos grande y extragrande mostraron una virulencia intermedia (LD 50: 10 – 5  con relación a los anteriores. Los análisis de secuencia de las variantes sobre una región comprendida entre el extremo 3´NS5 y el inicio de 3´NCR, mostró la cercanía entre aquellas variantes con algún grado de virulencia, y entre la variante atenuada y la vacuna colombiana. La heterogeneidad de la vacuna 17D, constituye una evidencia de la estructura de quasiespecies propia de los virus RNA y señala cómo los casos de reacciones post vacunales  adversas pueden estar asociados con la aplicación de vacunas fabricadas a partir de cepas virales atenuadas.  

La comunicación expresiva en niños con multidiscapacidad sin lenguaje verbal

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María Alejandra GRAZONA

2011-04-01

Full Text Available La investigación estuvo centrada en niños con multidiscapacidad que se comunican a través de canales no visuales y no verbales. A partir de la pregunta central respecto a: ¿Cómo dan a conocer el contenido de sus mensajes los niños con multidiscapacidad que no poseen lenguaje verbal?, implementamos un estudio con dos fases complementarias y de convergencia metodológica. La primera, amparada en el paradigma positivista, en la que realizamos un acercamiento objetivo a la realidad y por medio de la operacionalización de los conceptos teóricos. en la segunda fase, profundizamos a través de la Metodología de estudio de Caso (9 en total y con un anclaje en el paradigma fenomenológico-interpretativo. El objetivo perseguido fue: Conocer las formas comunicativas de niños con multidiscapacidad sin lenguaje verbal, por ello privilegiamos el análisis en profundidad a partir de la utilización de diferentes técnicas que permitieron el acercamiento a los niños en ambientes naturales y triangular la información para proporcionar fiabilidad y validez. Las mencionadas etapas permitieron obtener un conocimiento holístico de las formas comunicativas idiosincráticas utilizadas por los niños con multidiscapacidad, que, a modo de bisagra, constituyen su fenotipo comunicativo.

Antimicrobial Resistance Profile of Planktonic and Biofilm Cells of Staphylococcus aureus and Coagulase-Negative Staphylococci

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Adilson de Oliveira

2016-09-01

Full Text Available The objective of the present study was to determine the antimicrobial resistance profile of planktonic and biofilm cells of Staphylococcus aureus and coagulase-negative staphylococci (CoNS. Two hundred Staphylococcus spp. strains were studied, including 50 S. aureus and 150 CoNS strains (50 S. epidermidis, 20 S. haemolyticus, 20 S. warneri, 20 S. hominis, 20 S. lugdunensis, and 20 S. saprophyticus. Biofilm formation was investigated by adherence to polystyrene plates. Positive strains were submitted to the broth microdilution method to determine the minimum inhibitory concentration (MIC for planktonic and biofilm cells and the minimal bactericidal concentration for biofilm cells (MBCB. Forty-nine Staphylococcus spp. strains (14 S. aureus, 13 S. epidermidis, 13 S. saprophyticus, 3 S. haemolyticus, 1 S. hominis, 3 S. warneri, and 2 S. lugdunensis were biofilm producers. These isolates were evaluated regarding their resistance profile. Determination of planktonic cell MIC identified three (21.4% S. aureus strains that were resistant to oxacillin and six (42.8% that were resistant to erythromycin. Among the CoNS, 31 (88.6% strains were resistant to oxacillin, 14 (40% to erythromycin, 18 (51.4% to gentamicin, and 8 (22.8% to sulfamethoxazole/trimethoprim. None of the planktonic isolates were resistant to vancomycin or linezolid. MICs were 2-, 4-, 8-, and up to 16-fold higher for biofilm cells than for planktonic cells. This observation was more common for vancomycin and erythromycin. The MBCB ranged from 8 to >256 µg/mL for oxacillin, 128 to >128 µg/mL for vancomycin, 256 to >256 µg/mL for erythromycin and gentamicin, >64 µg/mL for linezolid, and 32/608 to >32/608 µg/mL for sulfamethoxazole/trimethoprim. The results showed considerably higher MICs for S. aureus and CoNS biofilm cells compared to planktonic cells. Analysis of MBCM confirmed that even high concentrations of vancomycin were unable to eliminate the biofilms of S. aureus and CoNS

Aspectos de la respuesta inmune innata en las infecciones intramamarias causadas por Staphylococcus aureus en bovinos

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Elizabet A.L Pereyra

2014-12-01

Full Text Available Staphylococcus aureus es el principal agente causante de mastitis bovina en Argentina y en el mundo. Esta bacteria ocasiona infecciones crónicas que generan importantes pérdidas a los productores y la industria lechera. El objetivo de este artículo es caracterizar los mecanismos que intervienen en la infección causada por S. aureus en la glándula mamaria bovina, evaluando dos aspectos diferentes del proceso infeccioso: por un lado, lo vinculado con la respuesta inmune innata por parte del hospedador, y por otro, la capacidad de la bacteria para evadir el sistema inmune e interactuar con diferentes tipos celulares. La exploración de la interacción de S. aureus con el sistema inmune de la glándula mamaria bovina permitirá identificar blancos para delinear nuevas alternativas preventivas o curativas, que contribuyan a evitar o eliminar las infecciones causadas por este organismo.

Competencia morfogénica de embriones maduros de Pinus radiata cultivados in vitro y su relación con la posición del cono en el árbol

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Sánchez-Olate, Manuel; Zapata Valenzuela, Jaime; Sáez Delgado, Patricia; Ríos Leal, Darcy; Spiercolli Henríquez, Scarlette; Alvarez Maldini, Carolina; Delaveau, Catherine; Pereira Cancino, Guillermo

2008-01-01

La micropropagación de material embrionario colectado de árboles adultos constituye una alternativa importante en la propagación masiva de fenotipos selectos, adecuados para los programas de clonación implementados por las empresas forestales. Utilizando esta técnica, ejes embrionarios maduros extraídos desde conos lignificados ubicados a diferentes alturas en el árbol (zonas basal, media y apical) fueron introducidos in vitro con el objeto de analizar la posible relación entre el estado fisi...

Inmunofenotipaje y supervivencia global de pacientes pediátricos con leucemias agudas Immunophenotyping and global survival of pediatric patients with acute leukemia

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Vianed Marsán Suárez

2002-04-01

Full Text Available El inmunofenotipaje celular (IFC permite identificar la línea específica de origen de las células leucémicas y su nivel de maduración. Se determinó la frecuencia de los distintos subtipos inmunológicos de leucemias agudas (LA y su posible relación con la supervivencia global de los pacientes. Se estudiaron 117 niños con LA entre 1983 y 1999. El IFC se realizó mediante el ultramicrométodo inmunocitoquímico y el de fosfatasa alcalina-antifosfatasa alcalina. Del total de LA, 77(65,8 % fueron linfoides agudas (LLA, 26 (22,2 % mieloides agudas, 9 (8 % LA indiferenciadas y 5 (4 % se clasificaron como LA híbridas. Del total de LLA, 59 (76,6 % fueron de fenotipo B y 18 (23,4 % de fenotipo T. Se observó una mayor sobrevida en los pacientes de linaje B en relación con los de linaje T y mieloide, con una diferencia muy significativa (p Cell immunophenotyping (CIP identifies the specific line of origin of leukemic cells and their maturing level. The frequency of the various immunological subtypes of acute leukemias (AL and their possible relationship with global survival rate of patients were determined. One hundred and seventeen children with AL were studied from 1983 to 1999. The CIP was conducted through the immunocytochemical ultramicromethod and the alkaline phosphatase - anti-alkaline phosphatase method. Seventy seven (65,8% of all AL were acute lymphoid leukemias (ALL, 26(22,2% acute myeloid (AML, 9 (8% undifferentiated AL, and 5 (4% were hybrid AL. Fifty-nine (76,6% ALL belonged to phenotype B and 18 (23,4% to phenotype T. A higher survival rate was observed in phenotype B ALL patients than in phenotype T ALL and myeloid anemia patients, with a very significant difference (p< 0,001. Survival was also analyzed among the various types of phenotype B acute leukemias; a lower survival rate was observed in patients with more immature phenotypes

Portadores nasales de Staphylococcus aureus en personal que labora en un Hospital de Santander Nasal carriers of Staphylococcus aureus in the personnel that works in a Hospital of Santander

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Cindy Tatiana Espinosa González

2011-08-01

Full Text Available Introducción: Las infecciones intrahospitalarias constituyen un problema de salud pública mundial, la diseminación de bacterias patógenas a partir del personal de salud, ha sido el enfoque de numerosas investigaciones que buscan mejorar la calidad de vida de los pacientes. Objetivo: Determinar la frecuencia de portadores de Staphylococcus aureus en fosas nasales del personal que labora en las unidades de cuidados intensivos, infectología pediátrica y lactario en un Hospital en Santander. Metodología: Se estudiaron muestras provenientes de fosas nasales de 87 trabajadores del Hospital. Las cepas aisladas se identificaron mediante las pruebas bioquímicas y posteriormente, se determinó el perfil de susceptibilidad ante diferentes antibióticos, se realizó test D a las cepas de S. aureus. Resultados: La frecuencia de portadores de bacterias patógenas fue 41,4%; el patógeno aislado con mayor frecuencia fue S. aureus (72%, donde el porcentaje de S. aureus meticilino-resistentes (SARM fue de 11,6%, Enterobacter aerogenes (6%, Proteus mirabilis (2,3%, Haemophylus influenzae (1,1%, Citrobacter koseri (1,1% y Providencia rettgeri (1,1%. Conclusión: S. aureus es el agente aislado con mayor frecuencia de las fosas nasales del personal de salud y la presencia de SARM es preocupante por su resistencia a los antibióticos, lo que dificulta su tratamiento. Este hecho evidencia la necesidad de actuar con un carácter preventivo, en el cual el control de portadores es crítico y debe asociarse con medidas de bioseguridad que establezcan barreras más eficientes, para reducir la diseminación del microorganismo y la ocurrencia de infecciones intrahospitalarias. Salud UIS 2011; 43 (2: 111-117Introduction: Nosocomial infections are a public health problem worldwide, its spread start from health personnel carrier of pathogenic bacteria, it has been the focus of a large number of research to improve the quality of life of the patients. Objective: To

STAPHYLOCOCCUS AUREUS IN NURSING PROFESSIONALS AND THE MICROORGANISM’S SUSCEPTIBILITY PROFILE TO ANTIMICROBIALS

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Letícia Pimenta Lopes

2017-01-01

Full Text Available Objetivo: identificar el estado del cargador y el perfil de susceptibilidad a los antibióticos de los Staphylococcus aureus aislados de la saliva y de la secreción nasal de los profesionales de enfermería. Método: estudio transversal, que utilizó muestras de saliva y secreción nasal, obtenidas de 100 profesionales de enfermería que asisten a personas con VIH/SIDA. Resultados: se identificó que 43,0% de los participantes presentaron muestras de saliva y/o secreción nasal positiva por Staphylococcus aureus . De las 74 muestras de secreción nasal con Staphylococcus aureus , 14,9% presentaron resistencia a la oxacilina; 91,9% a la penicilina; 44,6% a la eritromicina y 41,9% a la clindamicina. De las 12 muestras de saliva positivas, 16,7% fueron resistentes a la oxacilina; 100% a la penicilina; 33,4% a la eritromicina y 25,0% a la clindamicina. Conclusión: se cree que el profesional al obtener conocimiento de su estado de portador del microorganismos multi-resistentes, pasará a supervisar sus prácticas asistenciales y adoptar con mayor eficacia las medidas para la prevención y el control de la cadena epidemiológica de estas bacterias en el ambiente laboral.

ASMA SEVERA EN ADULTOS: ENFOQUE DIAGNÓSTICO Y TRATAMIENTO

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Paulina Barría P., DRA.

2015-05-01

Full Text Available El asma es una enfermedad frecuente de fisiopatología compleja. El asma severa constituye aproximadamente el 5% de la población de asmáticos, sin embargo representa un desafío clínico y una carga sanitaria importante. Estudios recientes demuestran la existencia de fenotipos en todo el espectro de gravedad. La eosinofilia en esputo y sangre ha demostrado utilidad como marcador de inflamación Th-2 y de respuesta clínica a esteroides, sin embargo aún no existe mucho conocimiento sobre el asma no-eosinofílica. Los tratamientos actuales en asma se enfocan a estrategias de terapia escalonada según severidad, pero en pacientes con asma severa se requiere también del manejo multidisciplinario de las comorbilidades y la determinación del fenotipo, para aplicar terapias más especificas. El desarrollo acelerado de nuevos tratamientos en asma severa como consecuencia del mejor conocimiento de los distintos fenotipos ha ampliado el arsenal terapéutico para un enfrentamiento personalizado y específico en los pacientes con asma severa.

Prevalence of nasal portal of Staphylococcus aureus in disabled children.

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Clotilde Molin

2016-06-01

Full Text Available Introduction: Colonization of the nasal mucosa by Staphylococcus aureus set a carrier state. Which is recognized as a potential source of infection and a high risk factor for subsequent invasive infections. The prevalence of nasal carriage of this germ in disabled children in Paraguay is not known, thus contributing to the knowledge of their frequency and evaluate the profile of sensitivity to common antimicrobials was conducted this study, from May to July 2015.  Objective: to determine the prevalence of Staphylococcus aureus nasal carriage and profile of antimicrobial resistance in disabled children. Materials and Methods: A descriptive cross-sectional study in which 80 nasal swabs of children, who attended the service laboratory of SENADIS (Secretaria Nacional por los Derechos Humanos de las Personas con Discapacidad. The identification and sensitivity of germ was accomplished by conventional testing.  Results: 80 pediatric patients, 46 boys and 34 girls. 18 isolates of Staphylococcus aureus were obtained, corresponding to a prevalence of 22,5%. Susceptibility testing indicated that 14 strains were MSSA (Methicillin – Sensitive Staphylococcus aureus and 4 RMSA ( Methicillin- resistant Staphylococcus aureus. Conclusion: The prevalence of Staphylococcus aureus in a population with its own characteristics provides valuable data for the epidemiology, reflecting the need for continued vigilance and take steps to reduce associated infections. The detection of RMAR evidences their progress; it is important to evaluate the empirical treatment to primary care.

Rapid differentiation of Staphylococcus aureus, Staphylococcus epidermidis and other coagulase-negative staphylococci and meticillin susceptibility testing directly from growth-positive blood cultures by multiplex real-time PCR.

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Jukes, Leanne; Mikhail, Jane; Bome-Mannathoko, Naledi; Hadfield, Stephen J; Harris, Llinos G; El-Bouri, Khalid; Davies, Angharad P; Mack, Dietrich

2010-12-01

This study evaluated a multiplex real-time PCR method specific for the mecA, femA-SA and femA-SE genes for rapid identification of Staphylococcus aureus, Staphylococcus epidermidis and non-S. epidermidis coagulase-negative staphylococci (CoNS), and meticillin susceptibility testing directly in positive blood cultures that grew Gram-positive cocci in clusters. A total of 100 positive blood cultures produced: 39 S. aureus [12 meticillin-resistant S. aureus (MRSA), 31% of all the S. aureus]; 30 S. epidermidis (56.6% of the CoNS), 8 Staphylococcus capitis (15.1%), 3 Staphylococcus saprophyticus (5.7%), 4 Staphylococcus hominis (7.5%), 3 Staphylococcus haemolyticus (5.7%), 2 Staphylococcus warneri (3.8%), 1 Staphylococcus cohnii (1.9%) and 2 unidentified Staphylococcus spp. (3.8%); and 1 Micrococcus luteus in pure culture. Two blood cultures had no growth on subculture and five blood cultures grew mixed CoNS. For the 95 blood cultures with pure growth or no growth on subculture, there was very good agreement between real-time PCR and the BD Phoenix identification system for staphylococcal species categorization in S. aureus, S. epidermidis and non-S. epidermidis CoNS and meticillin-resistance determination (Cohen's unweighted kappa coefficient κ=0.882). All MRSA and meticillin-susceptible S. aureus were correctly identified by mecA amplification. PCR amplification of mecA was more sensitive for direct detection of meticillin-resistant CoNS in positive blood cultures than testing with the BD Phoenix system. There were no major errors when identifying staphylococcal isolates and their meticillin susceptibility within 2.5 h. Further studies are needed to evaluate the clinical benefit of using such a rapid test on the consumption of glycopeptide antibiotics and the alteration of empiric therapy in the situation of positive blood cultures growing staphylococci, and the respective clinical outcomes.

Incidenza della meticillino-resistenza in Staphylococcus aureus e stafilococchi coagulasi-negativi isolati da emocolture

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Alessandra Siddi

2007-12-01

Full Text Available Background: Staphylococci are major cause of nosocomial blood stream infections.This local surveillance study was carry out to monitor frequency of occurrence of Staphylococcus aureus and coagulase-negative staphylococci (CoNS in blood stream infections and the incidence of methicillin-resistant (MET-R strains. Materials and methods: During the period January – December 2006, 9840 blood specimens were analyzed and microrganisms from positive samples were collected. Bacterial identifications were performed according to the standard methods (Murray, 2003.We evaluated, in particular, the antibiotic-resistance phenotype of staphylococci employing disk diffusion test as suggested by the CLSI (2006. The following antimicrobial agents were tested: oxacillin, penicillin, amoxiciclin-clavulanate, cefalotin, cefamandole, imipenem, teicoplanin, linezolid, ciprofloxacin, erythromycin, clindamicin, rifampicin, trimethoprim-sulfamethoxazole, gentamicin, doxiciclin, fosfomycin. Results: The microrganisms isolated were 551: 370 Gram-positives (67%, 131 Gram-negatives (24%, 11 anaerobes (2% and 39 mycetes (7%. In particular, 121 S. epidermidis, 75 S. aureus, 42 S. haemolyticus and other 39 CoNS were analyzed: methicillin-resistance occurred in more than 80% of S.aureus strains collected from Intensive Care Units (ICU and in about 50 % of those isolated from other divisions. In CoNS the incidence of MET-R ranged from 30 to 80 %, the higher values were registered among S. epidermidis and S. haemolyticus. MET-R strains were characterized by high resistance rates even to ciprofloxacin (from 47 to 100%, erythromycin (from 70 to 100%, and in same cases to gentamicin (from 23 to 86% also. Conclusions: Staphylococci are the prevalent cause of blood stream infections.The distinctive feature of MET-R strains is their resistance not only to all b-lactam antibiotics, but also to a wide range of other antimicrobial agents. However, the glycopeptide teicoplanin remains 100

Portadores nasofaríngeos de Neisseria meningitidis en trabajadores con riesgo ocupacional

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Isabel Martínez

2010-04-01

Full Text Available Los portadores de Neisseria meningitidis constituyen la principal fuente de infección y transmisión de la enfermedad meningocócica. Conocer su prevalencia, las características de las cepas aisladas y los factores de riesgos asociados con el estado de portador, aportan datos valiosos al control y vigilancia epidemiológica de esta entidad clínica. Para cumplimentar los objetivos propuestos se realizó un estudio transversal descriptivo de portadores de N. meningitidis en 112 trabajadores de un centro de producción de biofarmacéuticos de La Habana, con edades comprendidas entre 18_60 años. Previo a su realización se cumplió con las exigencias bioéticas requeridas para este tipo de estudio. A todos se les realizó un exudado nasofaríngeo y una encuesta, donde se indagó sobre factores de riesgo (edad, sexo, hacinamiento, hábito de fumar, consumo de bebidas alcohólicas, amigdalectomía y antecedentes de infección respiratoria que favorecen la condición del portador. La identificación de las cepas de N. meningitidis se realizó según métodos convencionales, la clasificación de los serogrupos se hizo por aglutinación en láminas portaobjetos con antisueros comerciales y para la identificación de los serotipos y subtipos se empleó un ensayo inmunoenzimático (ELISA de células enteras con anticuerpos monoclonales. Se detectó un 8% de portadores de N. meningitidis con predominio del serogrupo B (77,8% y el fenotipo más frecuente fue el B:4:P1.4 (33,3%. Al analizar el estado de portador y su asociación con los factores de riesgo, la edad (p = 0,05 y el sexo (p = 0,013 mostraron diferencias significativas. Se demostró la posibilidad del riesgo ocupacional en aquellos individuos que por su profesión están en contacto con microorganismos patógenos

Prevalencia de Staphylococcus aureus resistente a meticilina en infecciones de piel y partes blandas en pacientes ambulatorios

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Verónica Bermejo

2012-08-01

Full Text Available Recientemente se ha observado un aumento en la prevalencia de Staphylococcus aureus resistente a la meticilina (SAMR en pacientes ambulatorios con infecciones de piel y partes blandas (IPyPB. Los datos epidemiológicos locales disponibles son limitados. Se realizó un estudio descriptivo, prospectivo, de consultantes con IPyPB en la División Infectología del Hospital General de Agudos Juan A. Fernández, en el período 01/10/2009 a 31/01/2011. Fueron 130; edad mediana 36 años (RIC 25.9-43.5; hombres 61.5%. El 46.9% era HIV+. Cien cultivos (76.9%, de 100 pacientes, resultaron positivos: 83 S. aureus, 8 Streptococcus spp. y 9 con otros microorganismos. De los S. aureus aislados, 62 (74.7% fueron resistentes a oxacilina, 12 (14.4% a clindamicina, 14 (16.9% a eritromicina, 5 (6% a ciprofloxacina, presentando en algunos casos más de una resistencia. Todos fueron sensibles a rifampicina y minociclina, y 98.8% (82 a trimetoprima-sulfametoxazol. El 83.8% (52 de los pacientes con SAMR tenían algún factor de riesgo (FR, sin diferencias con los pacientes con otros aislamientos. La presentación clínica más frecuente de IPyPB / SAMR fue forunculosis: 56.4 (35/62 vs. 28.9% (11/38 en infecciones por otros microorganismos (p = 0.013. La resistencia a oxacilina fue similar entre pacientes HIV+ y negativos (79.1 vs. 70%, p = 0.179 (34/43 vs. 28/40. Concluimos que en la población estudiada se encontró una alta prevalencia de SAMR, independientemente de la serología para HIV o la presencia de FR. Las opciones de tratamiento empírico para este microorganismo son minociclina y trimetoprima-sulfametoxazol.

Neutropenia Inmune - Aloinmune neonatal: IgG sérica reactiva y fenotipo específico de los neutrófilos evaluados por citometría de flujo Autoimmune-alloimmune neonatal neutropenia: Serum reactive IgG and neutrophil-specific phenotype detected by flow cytometry

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Norma E. Riera

2006-10-01

Full Text Available La neutropenia inmune se diagnostica por la presencia de auto o aloanticuerpos reactivos con los neutrófilos. La neutropenia aloinmune neonatal es consecuencia de la sensibilización materna a los antígenos específicos de los neutrófilos paternos que afectan al neonato al atravesar la barrera placentaria. Se presentan 4 casos de niños, 2 de ellos hermanos consanguíneos con doble vínculo. Se estudiaron los sueros de los pacientes y sus padres. Por citometría de flujo se establecen los valores de referencia de la IgG sérica reactiva con los neutrófilos en voluntarios sanos, para 3 diluciones (1/2, 1/5 y 1/20 en reacción autóloga (suero y células de un mismo individuo y heteróloga (suero y células de diferentes individuos. Los resultados se expresan por un índice definido como el cociente entre la mediana de la intensidad de fluorescencia media del suero incógnita y la de un suero utilizado como referencia. Por leucoaglutinación se evaluó la dilución del suero 1/20. Se determinó el nivel de complejos inmunes circulantes. Se determinó el fenotipo, para los epitopes HNA-1a, HNA-1b y HNA-2a. En los 4 niños se encontró IgG reactiva y/o factores aglutinantes; 2/3 sueros maternos fueron reactivos con los neutrófilos del cónyuge y de los hijos. Los complejos inmunes circulantes fueron positivos en 2/4 sueros negativos en 3/3 sueros maternos. Se encontró incompatibilidad materno-infantil en los 4 casos. Las 3 madres tenían igual fenotipo: homocigotos NA1/NA1, NB1+. En síntesis, se presenta el hallazgo de 4 casos con neutropenia inmune: 3/4 auto-inmune, 1/3 se asocia a complejos inmunes circulantes y 1/4 con neutropenia neonatal aloinmune.Auto or alloantibodies reactive with neutrophils define immune neutropenia. Alloimmune neonatal neutropenia is caused by maternal sensitization to paternal neutrophil antigens, resulting in IgG antibodies that are transferred to the fetus through the placenta. We present the studies in 4

Staphylococcus aureus detection in the mouth of housekeepers Detección de Staphylococcus aureus en la boca de trabajadores de la limpieza hospitalaria Detecção de Staphylococcus aureus na boca de trabalhadores da limpeza hospitalar

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Elaine Drehmer de Almeida Cruz

2011-02-01

Full Text Available This study assessed the prevalence of colonization by Staphylococcus aureus in hospital housekeepers, and their knowledge and beliefs regarding this problem. Three saliva samples were collected and a questionnaire regarding knowledge and beliefs was applied. Of the 92 workers, 63 (68.5% participated in the study; 20 were not and 43 were colonized; 13 by methicillin resistant Staphylococcus aureus and 30 by methicillin sensitive Staphylococcus aureus. Persistent carrier status of methicillin resistant Staphylococcus aureus was detected in 15.4% of cases. Low knowledge and perception of occupational risk were observed. The mouth was identified as an important reservoir of methicillin resistant Staphylococcus aureus. Analyzing knowledge and beliefs, as well as the state of carrier, is an important strategy to be added to educational actions for the prevention of workers' colonization.Este estudio evaluó la prevalencia de la colonización por Staphylococcus aureus en trabajadores de limpieza hospitalaria, y su conocimiento y creencias acerca de la problemática. Fueron recolectadas tres muestras de saliva y aplicado un cuestionario referente al conocimiento y creencias. De 92 trabajadores, 63 (68,5% participaron del estudio; 20 se presentaron no colonizados y 43 colonizados; 13 para Staphylococcus aureus resistente a la meticilina y 30 para Staphylococcus aureus sensibles a la meticilina. El estado de portador persistente por Staphylococcus aureus resistente a la meticilina fue detectado en 15,4% de los casos. Bajo conocimiento y percepción del riesgo ocupacional fueron observados. La boca fue identificada como importante reservatorio de Staphylococcus aureus resistente a la meticilina. Analizar el conocimiento y creencias juntamente con la investigación del estado de portador es una importante estrategia a ser agregada a las acciones educativas para la prevención de la colonización de trabajadores.Este estudo avaliou a prevalência da coloniza

DETERMINACIÓN DEL ESTADO NUTRICIONAL EN PACIENTES CON ENFERMEDAD PULMONAR OBSTRUCTIVA CRÓNICA DEL PROGRAMA DE REHABILITACIÓN PULMONAR DEL HOSPITAL UNIVERSITARIO FUNDACIÓN SANTA FE DE BOGOTÁ DURANTE LOS AÑOS 2014-2015

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Estefanía Zuluaga

2017-11-01

Full Text Available Introducción: La Organización Mundial de la Salud (OMS estima que 65 millones de personas sufren de Enfermedad Pulmonar Obstructiva Crónica (EPOC moderada o severa siendo una enfermedad crónica cuyos fenotipos se encuentran relacionados con el estado nutricional y generan efectos metabólicos, y también sistémica multiorgánica progresiva, presenciando cambios estructurales y funcionales adversos en tejidos coronarios y musculo-esqueléticos. En 1968 Filley describió dos fenotipos en la enfermedad pulmonar avanzada: el llamado soplador azul, hoy denominado bronquítico y el soplador rosado, conocido como enfisematoso. El enfisematoso es un paciente desnutrido tendiendo hacia la caquexia; mientras que el bronquítico en su mayoría se encuentra en sobrepeso u obesidad, y presenta comorbilidades metabólicas. Objetivo: determinar el estado nutricional en pacientes con EPOC mediante la antropometría y el fenotipo para establecer una terapia multimodal caracterizada por tratamiento médico, nutricional y un plan de ejercicio que mejore las condiciones generales del paciente. Metodología: Se realizó un estudio observacional transversal, con recolección de la información de manera retrospectiva, analizando los registros clínicos de los pacientes del programa de Rehabilitación Pulmonar en el Hospital Universitario de la Fundación Santa Fe de Bogotá con EPOC en los años 2014 a 2015, con edad mayor de 18 años, el total de pacientes es de 37, 62% (n=23 mujeres; 38% (n= 14 hombres. Resultados: Hubo una mayor prevalencia de EPOC en mujeres no fumadoras y exfumadoras. Los pacientes, independientes del género, se encontraban en un 43,24% (n=16 en sobrepeso u obesidad, con un WHtR mayor o igual a 0.6, implicando el aumento en el riesgo cardiovascular, diabetes y síndrome metabólico. Los pacientes que presentaron bajo peso fueron un 10,81%(n=4, diferente a lo reportado en la literatura. Conclusión: Es necesario realizar estudios con

Staphylococcus aureus: methicillin-susceptible S. aureus to methicillin-resistant S. aureus and vancomycin-resistant S. aureus.

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Rehm, Susan J; Tice, Alan

2010-09-15

The evolution of methicillin-resistant and vancomycin-resistant Staphylococcus aureus has demanded serious review of antimicrobial use and development of new agents and revised approaches to prevent and overcome drug resistance. Depending on local conditions and patient risk factors, empirical therapy of suspected S. aureus infection may require coverage of drug-resistant organisms with newer agents and novel antibiotic combinations. The question of treatment with inappropriate antibiotics raises grave concerns with regard to methicillin-resistant S. aureus selection, overgrowth, and increased virulence. Several strategies to reduce the nosocomial burden of resistance are suggested, including shortened hospital stays and outpatient parenteral antimicrobial therapy of the most serious infections.

Colonization of nursing professionals by Staphylococcus aureus La colonización de los profesionales de enfermería por Staphylococcus aureus A colonização dos profissionais de enfermagem por Staphylococcus aureus

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Josely Pinto de Moura

2011-04-01

Full Text Available This cross-sectional study aimed to investigate the presence of Staphylococcus aureus in the saliva of the nursing team of a teaching hospital in the interior of São Paulo State. Three saliva samples were collected from 351 individuals with an interval of two months between each collection. All ethical aspects were considered. In 867 (82.3% cultures there was no identification of Staphylococcus aureus in the saliva, in 88 (17.7% cultures Staphylococcus aureus was isolated, 26 (2.5% of which were resistant to methicillin. The prevalence of professionals colonized by Staphylococcus aureus was 41.0% (144/351, of which 7.1% (25/351 were characterized as methicillin-resistant Staphylococcus aureus. Transient carriers represented 81.2% and persistent carriers 18.8%. Resistance to mupirocin was 73.1% of MRSA and 9.3% of MSSA. The results demonstrate that it is the nurse and nursing technician that are the professional categories most susceptible to MRSA. Broader discussion on the thematic and interventions are needed.Se trata de un estudio transversal que tuvo como objetivo investigar la presencia de Staphylococcus aureus en la saliva del equipo de enfermería de un hospital escuela del interior del estado de Sao Paulo. Fueron recolectadas tres muestras de saliva de 351 individuos con intervalo de dos meses. Todos los aspectos éticos fueron contemplados. En 867 (82,3% culturas no hubo identificación de Staphylococcus aureus en la saliva, en 88 (17,7% culturas fue aislado Staphylococcus aureus, siendo 26 (2,5% resistentes a la meticilina. La prevalencia de profesionales colonizados por Staphylococcus aureus fue de 41,0% (144/351, de los cuales 7,1% (25/351 fueron caracterizados como Staphylococcus aureus resistentes a la meticilina. Los portadores transitorios representaron 81,2% y los persistentes 18,8%. La resistencia a la mupirocina fue de 73,1% entre los resistentes a la meticilina y 9,3% en los sensibles a la meticilina. Los resultados

Comparison of four methods for rapid identification of Staphylococcus aureus directly from BACTEC 9240 blood culture system.

Science.gov (United States)

Ozen, N S; Ogunc, D; Mutlu, D; Ongut, G; Baysan, B O; Gunseren, F

2011-01-01

Differentiation of Staphylococcus aureus (S. aureus) from coagulase-negative staphylococci is very important in blood stream infections. Identification of S. aureus and coagulase-negative staphylococci (CoNS) from blood cultures takes generally 18-24 h after positive signaling on continuously monitored automated blood culture system. In this study, we evaluated the performance of tube coagulase test (TCT), slide agglutination test (Dry Spot Staphytect Plus), conventional polymerase chain reaction (PCR) and LightCycler Staphylococcus MGrade kit directly from blood culture bottles to achieve rapid identification of S. aureus by using the BACTEC 9240 blood culture system. A total of 129 BACTEC 9240 bottles growing gram-positive cocci suggesting Staphylococci were tested directly from blood culture broths (BCBs) with TCT, Dry Spot Staphytect Plus, conventional PCR and LightCycler Staphylococcus MGrade kit for rapid identification of S. aureus. The sensitivities of the tests were 99, 68, 99 and 100%, respectively. Our results suggested that 2 h TCT was found to be simple and inexpensive method for the rapid identification of S. aureus directly from positive blood cultures.

Immunoglobulin Fc receptors in clinical strains of Staphylococcus aureus do not confer resistance to Phagocytosis in an in vitro assay Los receptores Fc para inmunoglobulinas en cepas clínicas de Staphylococcus aureus no confieren resistencia a la fagocitosis in vitro

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Benito VEGA

1999-05-01

Full Text Available Staphylococcus aureus binds Immunoglobulin G (IgG on its external surface due to the presence of specific receptors for the Fc domain of this immunoglobulin. This mechanism represents a kind of camouflage against phagocytic cells. In order to confirm that possibility an in vitro evaluation of the phagocytic activity of leukocytes polymorpho-nuclear (PMN against strains of Staphylococcus aureus was done, comparing 18 strains isolated from clinical samples and 16 from healthy individuals. The presence of Fc receptors was evaluated by haemagglutination (HA with erythrocytes group A after incubation of the strains with IgG anti blood group A. Phagocytosis of S. aureus was carried out by mixing live bacteria with a suspension of human PMN and incubating at 37 °C for 1 h; survivors were counted as colony forming units by plating. The strains from clinical specimens showed higher HA than those from healthy individuals (p = 0.01; but the former were killed more efficiently than the latter (80-90% and 40%, respectively. It is may be possible that S. aureus showed different behavior in vivo, where could express other virulence factors to prevent the action of phagocytes.Staphylococcus aureus liga inmunoglobulinas G (IgG a su superficie externa debido a la presencia de receptores para el dominio Fc de esas inmunoglobulinas. Este mecanismo representa una clase de camuflage contra células fagocíticas. Para confirmar tal posibilidad se realizó una evaluación in vitro de la actividad fagocítica de leucocitos polimorfonucleares (PMN contra cepas de Staphylococcus aureus, comparando 18 cepas aisladas de casos clínicos y 16 de individuos sanos. La presencia de receptores fue evaluada por hemaglutinación (HA con eritrocitos grupo A luego que las cepas fueron incubadas con IgG anti grupo sanguíneo A. La fagocitosis de S. aureus fue realizada mezclando células vivas con una suspensión de PMN e incubada a 37 °C por una hora; las bacterias sobrevivientes

Inmunofenotipos aberrantes en leucemias agudas en una población hospitalaria de Buenos Aires Aberrant immunophenotypes in acute leukemia in a Buenos Aires' hospital population

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Viviana Novoa

2013-02-01

Full Text Available La citometría de flujo multiparamétrica es el método de elección para la caracterización inmunofenotípica de las células hematopoyéticas clonales presentes en los distintos procesos leucémicos agudos. El objetivo fue analizar la expresión de antígenos de membrana y evaluar la presencia de fenotipos aberrantes en los blastos de pacientes con diagnóstico de leucemia aguda, que permiten el monitoreo de la respuesta al tratamiento. Se revisaron los inmunofenotipos de 364 muestras de pacientes adultos derivadas a nuestro laboratorio en un período de 7 años. El inmunofenotipo se realizó por citometría de flujo con un amplio panel de anticuerpos monoclonales con el que se evaluó la expresión de antígenos de linaje linfoide, mieloide y también antígenos de maduración. De las 364 muestras estudiadas, 60.2% presentaron un fenotipo compatible con leucemia mieloide aguda (LMA, 28.8% con leucemia linfoblástica B (LLA-B, 6.6% con leucemia linfoblástica T (LLA-T y 4.4% con leucemias agudas poco frecuentes. La presencia de fenotipos aberrantes se observó en 89% de los casos, los fenotipos aberrantes identificados fueron: 1 infidelidad de linaje: LMA (54%, LLA-B (40%, LLA-T (29%; 2 ausencia de expresión antigénica: LMA (21%, LLA-B (35%, LLA-T (70%; 3 alteración de la expresión antigénica: LMA (67%, LLA-B (66%, LLA-T (84%; 4 asincronismo madurativo: LMA (26%, LLA-B (37% y 5 fenotipo ectópico: LLA-T 96%. El análisis por citometría de flujo multiparamétrica de las leucemias agudas permitió la identificación de fenotipos aberrantes en la mayoría de nuestros pacientes, que son de utilidad para el monitoreo de la respuesta al tratamiento.Multiparameter flow cytometry (MFC has become the preferred method for the lineage assignment and maturational analysis of malignant cells in acute leukemias. Multiparametric immunophenotyping analysis allows the detection of aberrant antigen expression and the analysis of heterogeneity and

Etmoiditis complicada con celulitis orbitaria en un lactante

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Odette Pantoja Pereda

Full Text Available Se define la etmoiditis como la inflamación e infección de la mucosa de las celdas etmoidales. Se diagnostica clínicamente con la presencia de edema en el ángulo medial del ojo, que se extiende a las estructuras adyacentes. Estudios imagenológicos son necesarios para verificar la presencia de complicaciones, entre las que se citan el absceso orbitario, subperióstico, epidural, subdural, cerebral, tromboflebitis del seno cavernoso, meningoencefalitis y la muerte del paciente. Streptococcus pneumoniae, Staphylococcus aureus y Haemophilus influenzae son microorganismos frecuentemente responsables de este cuadro. Las complicaciones orbitarias en las etmoiditis, necesitan el diagnóstico y tratamiento precoz para evitar secuelas irreversibles. Se presenta el caso de un lactante masculino, de 1 mes y 26 días de nacido, que ingresa con fiebre, rinorrea serosa y rechazo al alimento. Evolutivamente se constata marcada obstrucción nasal, edema periorbitario izquierdo, rubor, calor, protrusión del globo ocular e irritabilidad, y se diagnostica etmoiditis complicada con celulitis orbitaria. Se realiza tomografía axial computarizada que informa seno etmoidal izquierdo ocupado por contenido de densidad líquida con celularidad (15-25 UH, engrosamiento de partes blandas de la pared interna de la órbita que abomba, comprime y desplaza la musculatura orbitaria, y se extiende al párpado y al ala izquierda de la nariz desviando tabique blando; así como ligera proptosis, y disminución de la densidad ósea de la pared interna de la cavidad orbitaria. Se toma muestra para cultivo y se aísla Staphylococcus aureus meticillin resistente. Se comentan los elementos diagnósticos y su tratamiento, con el objetivo de llamar la atención de los pediatras para lograr el diagnóstico y tratamiento oportuno.

Comparison of four methods for rapid identification of Staphylococcus aureus directly from BACTEC 9240 blood culture system

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N S Ozen

2011-01-01

Full Text Available Purpose: Differentiation of Staphylococcus aureus (S. aureus from coagulase-negative staphylococci is very important in blood stream infections. Identification of S. aureus and coagulase-negative staphylococci (CoNS from blood cultures takes generally 18-24 h after positive signaling on continuously monitored automated blood culture system. In this study, we evaluated the performance of tube coagulase test (TCT, slide agglutination test (Dry Spot Staphytect Plus, conventional polymerase chain reaction (PCR and LightCycler Staphylococcus MGrade kit directly from blood culture bottles to achieve rapid identification of S. aureus by using the BACTEC 9240 blood culture system. Materials and Methods: A total of 129 BACTEC 9240 bottles growing gram-positive cocci suggesting Staphylococci were tested directly from blood culture broths (BCBs with TCT, Dry Spot Staphytect Plus, conventional PCR and LightCycler Staphylococcus MGrade kit for rapid identification of S. aureus. Results: The sensitivities of the tests were 99, 68, 99 and 100%, respectively. Conclusion: Our results suggested that 2 h TCT was found to be simple and inexpensive method for the rapid identification of S. aureus directly from positive blood cultures.

FRECUENCIA DE GRUPOS SANGUÍNEOS (SISTEMA ABO) ENTRE ESTUDIANTES DE LA UNIVERSIDAD DE CÓRDOBA SEDE BERÁSTEGUI

OpenAIRE

Luis Causil -Vargas; Luis Gómez -Mercado; Daniel Otero- Díaz; Luisa Moscote- Blanco; Luis Monterrosa- Mestra; Dallana Burgos –Flórez; Yonairo Herrera- Benavides

2016-01-01

Objetivo: El objetivo del estudio fue determinar la frecuencia y distribución de grupos sanguíneos ABO y factor Rh en los estudiantes en la Universidad de Córdo­ba, Colombia, sede Berástegui. Metodología: Mediante la realización de un estudio descriptivo, transversal, en una población total de 1.112, de la cual se obtuvo una muestra de 127 personas entre las edades de 17-27 años. Resultados: Los resultados mostraron que el fenotipo A es el fenotipo más común con 51,18%, seguido de tipo fenoti...

Diseño de dos metodologías moleculares para la rápida identificación de aislamientos de Staphylococcus aureus resistente a meticilina asociados a la comunidad en Colombia

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Javier Antonio Escobar

2012-06-01

Full Text Available Introducción. Los aislamientos de Staphylococcus aureus resistente a la meticilina asociado a la comunidad (SARM-AC, están aumentando la frecuencia de infecciones en personas sanas de la comunidad y en pacientes hospitalizados. En Colombia y en la región andina estos aislamientos tienen un componente genético relacionado con el clon pandémico USA300. Objetivo. Diseñar y estandarizar dos metodologías para la diferenciación rápida de aislamientos colombianos de S. aureus resistente a la meticilina asociado a la comunidad de los asociados al hospital (SARM-AH. Materiales y métodos. Se estandarizaron dos metodologías moleculares para la identificación de aislamientos de S. aureus resistente a la meticilina asociado a la comunidad. La primera se basa en la digestión diferencial con tres enzimas de restricción de los genes cinasa de carbamato (arcC y cinasa de guanilato (gmk para los tipos de secuencia 5 (ST5 y 8 (ST8, correspondientes a aislamientos de S. aureus resistente a la meticilina asociado al hospital y asociado a la comunidad, respectivamente. La segunda se basa en la amplificación por reacción en cadena de la polimerasa de cinco factores de virulencia que se encuentran de manera diferencial en estos aislamientos. Las dos metodologías fueron validadas en 237 aislamientos clínicos de S. aureus resistente a la meticilina. Resultados. Con la primera metodología se identificaron el 100 % y 93,2 % de los aislamientos de S. aureus resistente a la meticilina asociado a la comunidad y asociado al hospital, respectivamente. Con la segunda metodología se identificaron correctamente los dos tipos de aislamientos. Conclusiones. Estas dos metodologías son una buena alternativa en términos de ahorro en tiempo y dinero comparadas con otras técnicas, como la electroforesis en campo pulsado y la tipificación de secuencias multilocus para la rápida identificación de aislamientos de S. aureus resistente a la meticilina asociado a la

Estudio fenotípico comparativo de consorcios microbianos con actividad quitinolítica de sedimentos marinos y rizósfera

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Débora Alvarado

2014-06-01

Full Text Available Se colectaron 4 muestras de sedimentos tanto del fondo como de la orilla de la playa «Marbella», Callao y 4 muestras de tierra agrícola a nivel de rizósfera obtenidas de un viñedo de la localidad de «Grocio Prado» en la Provincia de Chincha, Ica. Se determinó la densidad poblacional de microorganismos heterotróficos con actividad quitinolítica presentes en estos ambientes, y se describió sus principales características fenotípicas. Para la cuantificación de las poblaciones se empleó el método del Número Más Probable (NMP. Los tubos con crecimiento positivo fueron sembrados en placas con Agar Quitina Granulada y Agar Quitina Coloidal que fueron incubadas a temperatura ambiental hasta por dos semanas. Con las colonias desarrolladas se realizaron las pruebas de Oxidación/Fermentación de Glucosa, Oxidasa, Catalasa, motilidad, presencia de flagelo, capacidad tintoreal al GRAM, producción de esporas y actividad quitinolítica semicuantitativa. Se elaboraron fenogramas con el programa NTSYS v.1,7. La mayor densidad de bacterias quitinolíticas fue encontrada en la rizósfera alcanzando niveles ³1,6 x 105 en tanto que en sedimentos marinos la densidad osciló entre 2,2 x 102 a 1,6 x 104 NMP/g. Luego del análisis de agrupamiento de los fenotipos mostrados por los consorcios estudiados, se encontró que presentaban características distintivas, exhibiendo ambas una gran diversidad fenotípica.

Genetic variants in the PPARD-PPARGC1A-NRF-TFAM mitochondriogenesis pathway are neither associated with muscle characteristics nor physical performance in elderly. [Variaciones genéticas en la vía de la mitocondriogénesis PPARD-PPARGC1A-NRF-TFAM no están asociadas ni con características musculares ni con rendimiento físico en personas mayores].

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Nuria Garatachea

2015-07-01

Full Text Available We studied the influence of genetic polymorphisms involved in the PPARD-PPARGC1A-NRF-TFAM mitochondriogenesis pathway (rs6949152, rs12594956, rs2267668, rs8192678, and rs1937 on muscle phenotypes (thigh muscles’ cross-sectional, maximal handgrip-strength and 30-second chair stand-test and Barthel index in Caucasian (Spanish community-dwelling old people (n=75, 21 men, 54 women; 71–94 years. We found no significant genetic associations with the studied phenotypes. Multiple, complex gene-environment and gene-gene interactions which are yet to be determined are likely to play a more determinant role. Resumen Se estudió la influencia de los polimorfismos genéticos implicados en la vía de mitocondriogénesis PPARD-PPARGC1A-NRF-TFAM (rs6949152, rs12594956, rs2267668, rs8192678 y rs1937 en distintos fenotipos musculares (sección transversal muscular del muslo, fuerza máxima de prensión manual y 30 segundos de sentarse-levantarse de una silla y en el índice de Barthel en personas mayores caucásicas (españoles (n = 75, 21 hombres, 54 mujeres; 71 a 94 años. No se encontraron asociaciones genéticas significativas con los fenotipos estudiados. Interacciones múltiples, complejos gen-ambiente y relaciones gen-gen aún no determinadas podrían desempeñar un papel más determinante.

Modelo de estudio de dos informativas familias colombianas con Síndrome de Usher

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Tamayo ML.; González C.; Gelvez N.

2001-01-01

Establecer y evaluar un modelo de abordaje para el estudio del Síndrome de Usher, que abarca el diagnóstico clínico de los pacientes, establecimiento y confirmación del subtipo mediante estudios moleculares y posterior correlación genotipo-fenotipo.

Influencia de la edad y el género en los fenotipos y coeficientes de lateralidad en niños de 6 a 15 años

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M. Carmen Mayolas Pi; Joaquín Reverter Masià

2015-01-01

Este estudio valora la lateralidad manual, podal y ocular de 798 niños de 6 a 15 años. Se obtienen los fenotipos de lateralidad de cada niño (homogéneo, cruzado o no definido) y se comparan los resultados según el género y la edad (de 6-7 años, de 8-10 y de 11-15 años). Finalmente, se correlacionan las pruebas comparan y los coeficientes de lateralidad. Según nuestro estudio, el género no influye en la lateralidad del miembro superior, pero sí en el miembro inferior y en el ocular. La lateral...

Modelo de estudio de dos informativas familias colombianas con Síndrome de Usher

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C. González

2001-07-01

Full Text Available Establecer y evaluar un modelo de abordaje para el estudio del Síndrome de Usher, que abarca el diagnóstico clínico de los pacientes, establecimiento y confirmación del subtipo mediante estudios moleculares y posterior correlación genotipo-fenotipo.

Acción Bactericida del Jugo de Limón Sobre el Staphylococcus Aureus Rosenbach

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Obregón Botero. Rafael

1946-04-01

Full Text Available El objeto de este experimento fue el determinar la influencia que pudiera tener el jugo de limón común (citrus limonia Osbeck sobre el Staphylococcus; aureus Rosenbach. Esta bacteria se encuentra con frecuencia en la piel y el pelo del hombre y de los animales, también en el pus y con frecuencia asociados a muchas otras causantes de abcesos, forúnculos, nacidos, etc. Ocasionalmente pueden causar osteomielitis y endocarditis. En individuos tuberculosos las infecciones causadas por esta bacteria pueden ocasionar la muerte.

Relationship and susceptibility profile of Staphylococcus aureus infection diabetic foot ulcers with Staphylococcus aureus nasal carriage.

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Taha, Aza Bahadeen

2013-03-01

Staphylococcus aureus is the main cause of diabetic foot infection with the patient's endogenous flora as the principal source. Nasal carriage of S. aureus has been identified as an important risk factor for the acquisition of diabetic foot infections. The study assessment the associations of S. aureus with methicillin resistant S. aureus were isolation from diabetic foot infection and nasal carriage of the same patients and their antibiotic susceptibility profile. Diagnosis of S. aureus and methicillin resistant S. aureus were carried out by using standard procedures. Antibiotic sensitivity profiles were determent by breakpoint dilution method. Out of 222 S. aureus isolation, 139 (62.61%) were isolated from the diabetic foot and 83 (37.39%) from the nasal carriage. Seventy one (30.87%) of the patients were S. aureus infection diabetic foot with nasal carriage. Among diabetic foot infection and nasal carriage patients, 40.85% of S. aureus were considered as methicillin resistant S. aureus. Rifampicin (96.40%) and Levofloxacin (91.44%) were active against S. aureus. Patients at strong risk for methicillin resistant S. aureus nasal carriage and subsequent diabetic foot infection with high resistance to antibiotics. Copyright © 2012 Elsevier Ltd. All rights reserved.

Duplicación 5q34q35.3 que involucra el gen NSD1: región delimitada por microarreglos de hibridación genómica comparativa. A propósito de un caso

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AR Vázquez del Campo

2016-09-01

Full Text Available La duplicación de la región 5q34q35.3 se ha asociado a un fenotipo inverso de síndrome de Sotos, por contener el gen NSD1 en doble dosis. Se presenta a una paciente con retraso global del desarrollo, peso y talla bajos y dismorfias. Cuenta con antecedente de corrección quirúrgica por defectos de septación auriculoventricular (CIA y CIV, así como remodelación por antecedente de cráneo en trébol. El cariotipo con bandas G mostró un resultado 46,XX,add(5(q35, y para confirmar el origen del material adicional se utilizó sonda de FISH WCP para el cromosoma 5 [46,XX,add(5(q35.ish dup(5(q35(wcp5+]. Para definir puntos de ruptura y realizar correlación genotipo fenotipo se realizó microarreglo CytoScan HD de Affymetrix, que confirmó la duplicación intersticial de novo de 14Mb 46,XX,add(5(q35. arr[hg19] 5q34q35.3(163,110,984-177,227,216x3,177,259,401- 179,330,764x3,179,346,465 180,719,789x3dn, que contiene 80 genes (USCS genome browser, NCBI36/hg19. La descripción de este caso es importante para complementar la delineación del fenotipo, mediante la correlación con la región de la duplicación a nivel de nucleótidos. Cabe resaltar que la paciente demuestra la importancia y la utilidad de las nuevas técnicas de citogenética molecular, con las cuales es posible el análisis detallado de los genes localizados en la región 5q involucrada, así como su correlación con las manifestaciones clínicas.

Impacto de la resistencia a la meticilina sobre la mortalidad y vigilancia de la sensibilidad a la vancomicina en bacteriemias causadas por Staphylococcus aureus Impact of methicillin resistance on mortality and surveillance of vancomycin susceptibility in bacteremias caused by Staphylococcus aureus

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F. Traverso

2010-12-01

Full Text Available Staphylococcus aureus es uno de los principales patógenos nosocomiales y produce una alta morbimortalidad en numerosos hospitales del mundo. Además, la incidencia de bacteriemias por este microorganismo ha aumentado significativamente en las últimas décadas. Los objetivos del presente trabajo fueron identificar los factores de riesgo que favorecen la aparición de resistencia a la meticilina en aislamientos de S. aureus y los factores que afectan la mortalidad por bacteriemias asociadas a este patógeno, así como evaluar la sensibilidad a la vancomicina de las cepas resistentes a la meticilina. Se estudiaron 39 aislamientos de S. aureus provenientes de hemocultivos de pacientes internados con bacteriemia en la Nueva Clínica Chacabuco de Tandil (Pcia. de Buenos Aires, Argentina en el período 01/2006-12/2008. La mortalidad global fue del 51,3% y estuvo significativamente asociada con la resistencia a la meticilina (OR: 4,20; IC95%: 1,08-16,32; p: 0,05; aunque dicho factor no fue un predictor independiente de mortalidad. La cirugía previa (OR: 17,23; IC95%: 1,80-164,60 y la estancia previa en la unidad de cuidados intensivos (OR: 21,12; IC95%: 2,33-191,30 fueron predictores independientes de la resistencia a la meticilina y la asistencia respiratoria mecánica (OR: 15,99; IC: 3,24-78,86 fue un predictor independiente de la mortalidad. No se detectaron cepas con sensibilidad disminuida a la vancomicina. Todos los aislamientos estudiados fueron sensibles in vitro a la vancomicina, con una CIM50 y una CIM90 de 0,5 μg/ml.Staphylococcus aureus is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide. Besides, the incidence of S. aureus bacteremia has significantly increased over the past decades. The aims of this study were to detect the risk factors for methicillin resistance and mortality and to evaluate vancomycin susceptibility in methicillin-resistant isolates. Thus, 39 S. aureus isolates from

Mild Staphylococcus aureus Skin Infection Improves the Course of Subsequent Endogenous S. aureus Bacteremia in Mice.

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Sanne van den Berg

Full Text Available Staphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and evaluate protection in relation to anti-staphylococcal antibody levels. Skin infections once or twice by a clinical S. aureus isolate (isolate P or S. aureus strain 8325-4 were induced in mice free of S. aureus and anti-staphylococcal antibodies. Five weeks later, immunoglobulin G (IgG levels in blood against 25 S. aureus antigens were determined, and LD50 or LD100 bacteremia caused by S. aureus isolate P was induced. S. aureus skin infections led to elevated levels of anti-staphylococcal IgG in blood. One skin infection improved the course of subsequent severe endogenous bacteremia only. A second skin infection further improved animal survival rate, which was associated with increased pre-bacteremia IgG levels against Efb, IsaA, LukD, LukE, Nuc, PrsA and WTA. In conclusion, S. aureus isolate P skin infection in mice reduces the severity of subsequent endogenous S. aureus bacteremia only. Although cellular immune effects cannot be rules out, anti-staphylococcal IgG against specified antigens may contribute to this effect.

Polimorfismos en los genes CYP11α y CYP17 y etiología del hiperandrogenismo en pacientes con poliquistosis ovárica Polymorphism in CYP11alpha and CYP17 genes and the etiology of hyperandrogenism in patients with polycystic ovary syndrome

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María S. Pérez

2008-04-01

Full Text Available El síndrome de poliquistosis ovárica (PCOS es un desorden endocrino-metabólico de naturaleza multifactorial, con una marcada predisposición genética, que afecta al 6% de las mujeres en edad reproductiva. Se caracteriza por la presencia de hiperandrogenismo, oligo-anovulación y ovarios poliquísticos. Entre los genes candidatos se encuentran aquellos que codifican para enzimas que actúan en la síntesis de andrógenos. Dos de los genes candidatos son el CYP17 y el CYP11alfa que codifican para la 17alfa hidroxilasa (P45017alfa y para el P450scc (colesterol side chain cleavage respectivamente. Los polimorfismos en estos genes están asociados al desarrollo del fenotipo hiperandrogénico. Nuestro objetivo fue analizar las frecuencias alélicas de los polimorfismos de los dos genes mencionados en población con PCOS, compararla con población normal y analizar la relación de cada variante alélica con el fenotipo hiperandrogénico correspondiente. Se analizaron 65 pacientes y 58 controles sanos en los que se determinaron niveles de testosterona y frecuencia de polimorfismos en los genes mencionados. Se observó una diferencia estadísticamente significativa cuando se asoció el grupo de mayor nivel de androgenemia con la presencia del genotipo A2/A2 del gen CYP17, y se hallaron mayores niveles de andrógenos circulantes en las pacientes con PCOS portadoras del alelo 216- del gen CYP11alfa. Nuestros resultados sugieren que ambos alelos juegan un rol menor en el desarrollo de PCOS y podrían ser considerados como potenciales marcadores de riesgo genético para el desarrollo del fenotipo hiperandrogénico.The polycystic ovary syndrome (PCOS is a heterogeneous multifactorial endocrine metabolic disorder with genetic predisposition affecting 6% of women in the reproductive age. This syndrome is characterized by the presence of oligo-anovulation, hyperandrogenism and polycystic ovaries. Several genes have been postulated as responsible for the

Relationship between Vancomycin-Resistant Staphylococcus aureus, Vancomycin-Intermediate S. aureus, High Vancomycin MIC, and Outcome in Serious S. aureus Infections

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Holmes, Natasha E.; Johnson, Paul D. R.; Howden, Benjamin P.

2012-01-01

Vancomycin has been used successfully for over 50 years for the treatment of Staphylococcus aureus infections, particularly those involving methicillin-resistant S. aureus. It has proven remarkably reliable, but its efficacy is now being questioned with the emergence of strains of S. aureus that display heteroresistance, intermediate resistance, and, occasionally, complete vancomycin resistance. More recently, an association has been established between poor outcome and infections with strain...

Detección de mutaciones en los genes PAX3 y MITF en pacientes colombianos con Síndrome Waardenburg

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N. Gélvez

2001-07-01

Full Text Available Identificar las mutaciones en los genes PAX3 y MITF, responsables del Síndrome de Waardenburg en Colombia, determinar su frecuencia y establecer la correlación genotipo-fenotipo.

Control de la antibióticorresistencia en Escherichia coli : Enfoque farmacológico en el sistema animal-ambiente-hombre

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Marchetti, María Laura

2013-01-01

El objetivo central del presente trabajo de Tesis Doctoral fue restablecer in vitro la susceptibilidad antimicrobiana de cepas comensales de Escherichia coli (con fenotipo multirresistente-MDR-) aisladas de explotaciones pecuarias, mediante la asociación de diferentes antimicrobianos con el inhibidor de bombas de eflujo 1-(1-naphthylmethyl)-piperazine (NMP). De esta manera, se pretende contribuir al desarrollo de planes de dosificación de máxima eficacia antimicrobiana minimizando ...

Comparative Efficacy of Ceftaroline with Linezolid against Staphylococcus Aureus and Methicillin Resistant Staphylococcus Aureus

International Nuclear Information System (INIS)

Hafeez, A.; Munir, T.; Rehman, S.; Najeeb, S.; Gilani, M.; Latif, M.; Ansari, M.; Saad, N.

2015-01-01

Objective:To compare the in vitro antimicrobial efficacy of ceftaroline with linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Study Design: Quasi-experimental study. Place and Duration of Study: Microbiology Department, Army Medical College, Rawalpindi, from January to December 2013. Methodology: Clinical samples from respiratory tract, blood, pus and various catheter tips routinely received in the Department of Microbiology, Army Medical College, Rawalpindi were innoculated on blood and MacConkey agar. Staphylococcus aureus was identified by colony morphology, Gram reaction, catalase test and coagulase test. Methicillin resistant Staphylococcus aureus detection was done by modified Kirby Bauer disc diffusion method using cefoxitin disc (30g) and the isolates were considered methicillin resistant if the zone of inhibition around cefoxitin disc was /sup 2/ 21 mm. Bacterial suspensions of 56 Staphylococcus aureus isolates and 50 MRSA isolates were prepared, which were standardized equal to 0.5 McFarland's turbidity standard and inoculated on Mueller-Hinton agar plates followed by application of ceftaroline and linezolid disc (Oxoid, UK), according to manufacturer's instructions. The plates were then incubated at 37 Degree C aerobically for 18 - 24 hours. Diameters of inhibition zone were measured and interpretated as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Out of 106 isolates all of the 56 Staphylococcus aureus (100%) were sensitive to ceftaroline and linezolid. However, out of 50 methicillin resistant Staphylococcus aureus, 48 (96%) were sensitive to ceftaroline whereas, 49 (98%) were sensitive to linezolid. Conclusion: Ceftaroline is equally effective as linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. (author)

Análisis de micromatrices de ADN revela genes asociados a metástasis en líneas celulares de cáncer de próstata de rata

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Ismael Reyes

2007-06-01

Conclusiones. Se identificaron genes con expresión alterada asociados al fenotipo metastásico del cáncer de próstata. La subsiguiente validación de estos genes en tejido prostático humano pudiera revelar su utilidad como marcadores biológicos para esta enfermedad.

Estudio del efecto de enoxaparina sobre la cirrosis e hipertensión portal experimental

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Fortea Ormaechea, José Ignacio

2016-01-01

La administración de anticoagulantes en pacientes con cirrosis hepática es controvertida debido a que esta enfermedad ha sido considerada durante mucho tiempo un estado hipocoagulante. Sin embargo, en las últimas dos décadas se ha puesto de manifiesto que la hemostasia mantiene un equilibrio precario en pacientes con cirrosis hepática, pudiendo presentar tanto un fenotipo hipocoagulante como uno protrombótico, y que la anticoagulación en pacientes con cirrosis hepática no se asocia a un mayor...

Hiperlipidemia familiar combinada: documento de consenso

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Pedro Mata; Rodrigo Alonso; Antonio Ruíz-Garcia; Jose L. Díaz-Díaz; Noemí González; Teresa Gijón-Conde; Ceferino Martínez-Faedo; Ignacio Morón; Ezequiel Arranz; Rocío Aguado; Rosa Argueso; Leopoldo Perez de Isla

2014-01-01

La hiperlipidemia familiar combinada (HFC) es un trastorno muy frecuente asociado a enfermedad coronaria prematura. Se transmite de forma autosómica dominante, aunque no existe un gen único asociado al trastorno. El diagnóstico se realiza mediante criterios clínicos, y son importantes la variabilidad del fenotipo lipídico y la historia familiar de hiperlipidemia. Es frecuente la asociación con diabetes mellitus tipo 2, hipertensión arterial y obesidad central. Los pacientes con HFC se cons...

RELACIÓN ENTRE VARIABLES CLIMÁTICAS CON LA MORFOLOGÍA Y CONTENIDO DE ACEITE DE SEMILLAS DE HIGUERILLA (Ricinus communis L. DE CHIAPAS

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María Antonieta Goytia-Jiménez

2011-01-01

Full Text Available Ciento cincuenta y un accesiones de higuerilla (Ricinus communis L., colectadas en el estado de Chiapas, México, fueron caracterizadas por contenido de aceite, forma, tamaño y peso de la semilla, con el objetivo de generar información que pueda servir de base en un programa de mejoramiento para esta especie, que podría ser una opción rentable para la producción de biodiesel y bioturbosina. De acuerdo con su distribución, se establecieron las cuatro siguientes zonas climáticas: Región 1 clima Lluvioso tropical sin estación seca; Región 2 Sabana tropical con inviernos secos; Región 3 Sabana tropical con inviernos menos secos que la Región 2, y Región 4 Lluvioso Tropical. Se encontró una amplia variación en tamaño (de 0.05 a 2.49 cm2, color, peso (desde 7 hasta 123.9 g por cada 100 semillas y contenido de aceite (desde 12.20 a 64.84 %. Las asociaciones que se establecieron entre el tamaño y peso de 100 semillas con temperatura y precipitación fueron negativas, y significativas sólo en las regiones 3 y 4. No hubo significancia para las asociaciones del contenido de aceite con temperatura y precipitación, pero la tendencia fue a ser positivas en las regiones 1 y 4, las de mayor humedad de las cuatro regiones, y negativas en las regiones 2 y 3. Se concluye que los individuos de esta especie presentan una gran adaptación a diferentes entornos y crean fenotipos especiales para cada lugar en donde se desarrollan.

Staphylococcus aureus bacteriuria as a prognosticator for outcome of Staphylococcus aureus bacteremia: a case-control study

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Weinstein Robert A

2010-07-01

Full Text Available Abstract Background When Staphylococcus aureus is isolated in urine, it is thought to usually represent hematogenous spread. Because such spread might have special clinical significance, we evaluated predictors and outcomes of S. aureus bacteriuria among patients with S. aureus bacteremia. Methods A case-control study was performed at John H. Stroger Jr. Hospital of Cook County among adult inpatients during January 2002-December 2006. Cases and controls had positive and negative urine cultures, respectively, for S. aureus, within 72 hours of positive blood culture for S. aureus. Controls were sampled randomly in a 1:4 ratio. Univariate and multivariable logistic regression analyses were done. Results Overall, 59% of patients were African-American, 12% died, 56% of infections had community-onset infections, and 58% were infected with methicillin-susceptible S. aureus (MSSA. Among 61 cases and 247 controls, predictors of S. aureus bacteriuria on multivariate analysis were urological surgery (OR = 3.4, p = 0.06 and genitourinary infection (OR = 9.2, p = 0.002. Among patients who died, there were significantly more patients with bacteriuria than among patients who survived (39% vs. 17%; p = 0.002. In multiple Cox regression analysis, death risks in bacteremic patients were bacteriuria (hazard ratio 2.9, CI 1.4-5.9, p = 0.004, bladder catheter use (2.0, 1.0-4.0, p = 0.06, and Charlson score (1.1, 1.1-1.3, p = 0.02. Neither length of stay nor methicillin-resistant Staphylococcus aureus (MRSA infection was a predictor of S. aureus bacteriuria or death. Conclusions Among patients with S. aureus bacteremia, those with S. aureus bacteriuria had 3-fold higher mortality than those without bacteriuria, even after adjustment for comorbidities. Bacteriuria may identify patients with more severe bacteremia, who are at risk of worse outcomes.

Dengue virus infection down-regulates differentiation markers in neuroblastoma cells

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Rincón Forero, Verónica; Alvear Gómez, Diana; Solano Orjuela, Oscar; Prada-Arismendy, Jeanette; Castellanos Parra, Jaime Eduardo

2011-01-01

Introducción: cerca del 5% de los pacientes con dengue hemorrágico pueden presentar manifestaciones neurológicas; sin embargo, existe poca información sobre la infección directa por el virus dengue (DENV) en neuronas. Objetivo: determinar el papel del fenotipo neuronal en la infección por DENV en células de neuroblastoma SH-SY5Y inducidas o no a la diferenciación con ácido retinoico (AR). Materiales y métodos: células SH-SY5Y fueron inducidas con AR a diferenciarse e infectadas con DENV. Post...

Staphylococcus aureus entrance into the dairy chain: Tracking S. aureus from dairy cow to cheese

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Judith Kümmel

2016-10-01

Full Text Available Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. 1176 quarter milk (QM samples of all cows in lactation (n = 294 and representative samples form bulk tank milk (BTM of all farms were surveyed for coagulase positive (CPS and coagulase negative Staphylococci (CNS. Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing, dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day fourteen of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires effective clearance strategies and hygienic

Oligonucleotide IMT504 induces an immunogenic phenotype and apoptosis in chronic lymphocytic leukemia cells El oligonucleótido IMT504 induce un fenotipo immunogénico y apoptosis en células de leucemia linfocítica crónica

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Juan M. Rodríguez

2006-02-01

ún, las células B-LLC de todos los pacientes estudiados, desarrollaron un fenotipo inmunogénico y entraron en apoptosis luego de la incubación in vitro con IMT504, independientemente del estado mutacional de sus genes IgV H , un indicador del pronóstico de la patología.

Uso nasal de la mupirocina para Staphylococcus aureus: efecto en portadores y en infecciones nosocomiales.

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Ana María García

2003-06-01

Full Text Available Staphylococcus aureus es agente causal de infecciones intrahospitalarias y adquiridas en la comunidad. Entre 20% y 35% de la población adulta lo porta en el vestíbulo nasal y orofaringe de manera permanente y 50% de manera transitoria. La mupirocina de calcio tópica es un agente bactericida contra S. aureus que se recomienda para erradicar la colonización nasal y de manos en pacientes y personal hospitalario. Este trabajo se propuso determinar la prevalencia de S. aureus nasal en pacientes sometidos a cirugía cardiovascular y observar el efecto de la mupirocina nasal en la prevalencia de portadores nasales y en las infecciones nosocomiales. Se realizó un estudio experimental prospectivo para comparar los pacientes tratados con mupirocina nasal (n=96 y los no tratados (n=95. En todos se buscó la presencia de S. aureus nasal y la aparición de infección nosocomial. Se encontró una prevalencia general de portadores de 34%, una disminución de la prevalencia de 86,6% en el grupo tratado y una disminución de 33,3% en el grupo control, lo que mostró la mupirocina como factor protector. La proporción de infección nosocomial total fue de 17,3%, que se distribuyó en forma homogénea entre los dos grupos, pero las infecciones por S. aureus se presentaron en su mayoría en los pacientes control (6 de 7. Se demostró la eficiencia de la mupirocina en la eliminación de portadores nasales de S. aureus. Adicionalmente, el trabajo sugiere que el uso de este antibiótico no disminuye el número total de infecciones nosocomiales.

Deficiencia de glucosa-6-fosfato deshidrogenasa en un paciente con síndrome de Down

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Francisco R. Cammarata Scalisi

2012-07-01

Full Text Available El síndrome de Down, es una alteración genética que ocurre cuando un individuo exhibe todo o una parte específica adicional del cromosoma 21 y es la entidad más frecuentemente asociada a retardo mental. La deficiencia de glucosa-6-fosfato deshidrogenasa, es el defecto enzimático más común en humanos y presenta patrón de herencia ligado al cromosoma X recesivo. Se debe a la mutación del gen G6PD, el cual causa diversos fenotipos bioquímicos y clínicos. Reportamos un caso de lactante menor masculino, evaluado en la Unidad de Genética Médica de la Universidad de Los Andes, con el diagnóstico de deficiencia de glucosa-6-fosfato deshidrogenasa con doble mutación A376G y G202A y síndrome de Down con estudio citogenético 47, XY, +21. Palabras clave:Síndrome de Down; deficiencia de glucosa-6-fosfato deshidrogenasa; G6PD; A37G6; G202A. Glucose-6-phosphate dehydrogenase deficiency in a patient with Down syndrome Abstract Down syndrome, is a genetic disorder that occurring when an individual exhibits all or part of an extra copy of chromosome 21 and the most common entity associated mental retardation. Glucose-6-phosphate dehydrogenase deficiency, is the most common human enzyme defect and has a X-linked recessive inheritance. Due to mutations in the G6PD gene, which cause many biochemical and clinical phenotypes. We reported a case of child male, evaluated in the Unit of Medical Genetics of the University of The Andes, with diagnosis of glucose-6-phosphate dehydrogenase deficiency with double mutation A376G and G202A and Down syndrome with cytogenetic study 47, XY, + 21.

Variantes alélicas de CYP2D6: *4, *6 y *10 en una muestra de residentes del estado Aragua, Venezuela

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Carlos Flores-Angulo

Full Text Available El objetivo del estudio fue determinar la frecuencia de las variantes del gen CYP2D6: *4, *6 y *10 y predecir el fenotipo metabolizador en una muestra de 145 individuos no consanguíneos, aparentemente sanos, residentes del estado Aragua, Venezuela. Los genotipos fueron determinados mediante ensayos de reacción en cadena de la polimerasa seguidos de digestión con endonucleasas de restricción. La predicción del fenotipo metabolizador se realizó con base al sistema Activity score. Las frecuencias de CYP2D6 *4, *6 y *10 fueron de 14,5%, 0,3% y 1%, respectivamente; un porcentaje significativo de individuos fueron categorizados como metabolizador rápido heterocigoto/metabolizador intermedio (23,5% y metabolizador lento (4,1%. Esta información tiene impacto clínico potencial, porque CYP2D6 interviene en el metabolismo de fármacos de prescripción frecuente como: carvedilol, captopril, cloroquina, codeína, fluoxetina, fluvastatina, haloperidol, idarrubicina, indinavir, imatinib, loperamida, nifedipina, ondansetrón y tamoxifeno

Selección sexual relacionada con el tamaño corporal, parámetros genético-cuantitativos multivariados, y divergencia morfométrica multivariada entre poblaciones de dos especies cactófilas del genéro Drosophila

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Norry, Fabián Marcelo

1995-01-01

Los recientes avances conceptuales dentro del campo de la genética cuantitativa, han brindado las herramientas teóricas necesarias para caracterizar la evolución del fenotipo medio en poblaciones naturales. La teoria predice que la micro-evolución adaptativa del fenotipo depende de la forma de selección natural operando sobre los caracteres adaptativos, y particularmente de las varianzas y covarianzas genéticas y fenotípicas entre tales caracteres. Por ello, los estudios empíricos sobre estos...

Cinética de fermentación y acción antimicrobiana de Weissella confusa contra Staphylococcus aureus y Streptococcus agalactiae

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Liliana Serna Cock

2010-01-01

Full Text Available Se evaluaron las cinéticas de producción de biomasa, producción de ácido láctico, consumo de sustrato y actividad antimicrobiana de Weissella confusa, una bacteria acido láctica con actividad antimicrobiana frente a Streptococcus agalactiae y Staphylococcus aureus, microorganismos productores de mastitis bovina. Las fermentaciones se llevaron a cabo anaeróbicamente en discontinuo utilizando como sustratos, sustrato comercial (SC, leche suplementada con extracto levadura (LEL y leche suplementada con extracto de levadura y glucosa (LELG y se compararon los parámetros cinéticos. La mayor inhibición de los patógenos, la mayor producción de ácido láctico y el mayor rendimiento de biomasa se presentó en sustrato LELG. En éste último sustrato al cabo de la cuarta hora de fermentación, se presentó un diámetro de inhibición de 36,33 mm para Staphylococcus aureus y a la octava hora de fermentación 39 mm de diámetro para Streptococcus agalactiae; la producción máxima de ácido láctico fue 13,12 gL-1 (a las 48 h y la máxima concentración de biomasa fue 3,07 gL-1 (a las 48 h. Estos resultados fueron superiores a los obtenidos en SC donde, para el mismo tiempo de fermentación, se obtuvieron 24,38 mm para Staphylococcus aureus y 30,58 mm de diámetro de inhibición para Streptococcus agalactiae; la mayor producción de ácido láctico fue 11,6 gL-1 (a las 12 h y la mayor concentración de biomasa fue 1,18 gL-1 (a las 24 h. Los resultados sugieren que el LELG puede convertirse en una alternativa a bajo costo para la producción de Weissella confusa, microorganismo con gran potencial para el control y el tratamiento de mastitis bovina.

Marcadores fenotípicos de atenuación en cepas de virus Junín recuperadas de individuos vacunados con la cepa Junín Candid#1

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Graciela S. Gamboa

2013-08-01

Full Text Available La Fiebre Hemorrágica Argentina es una enfermedad producida por el virus Junín. Para la prevención de esta enfermedad se obtuvo una vacuna efectiva denominada Candid#1. Durante un ensayo clínico realizado en el INEVH, dos cepas de virus Junín fueron aisladas de sangre periférica de dos voluntarios mediante co-cultivo de células mononucleares. El objetivo de este trabajo fue comparar las características fenotípicas de atenuación de esas dos cepas recuperadas de humanos con las de la vacuna Candid#1 utilizando los indicadores de atenuación desarrollados por Contigiani y Sabattini en 1977. A tal fin se midieron los índices de letalidad, infección y protección en cobayos y ratones de diferentes edades. Las tres cepas investigadas resultaron letales para ratones recién nacidos pero no para ratones de 10 a 12 días, ratones adultos ni cobayos, aun a la más baja dilución inoculada. Los cobayos inoculados con las cepas recuperadas de humanos y con la cepa Candid#1 no presentaron síntomas de enfermedad y mostraron estar protegidos cuando fueron desafiados con una cepa patógena. Los índices de infección y de protección hallados indican que estas cepas poseen elevada capacidad infectante y protectora en las especies animales aquí estudiadas. Estos resultados demuestran que las cepas de virus Junín aisladas de voluntarios inmunizados con Candid#1 mantienen el mismo fenotipo atenuado de la vacuna Candid#1 después de un pasaje por humanos.

Methicillin-resistant Staphylococcus aureus (MRSA)

Science.gov (United States)

Methicillin-resistant Staphylococcus aureus; Hospital-acquired MRSA (HA-MRSA); Staph - MRSA; Staphylococcal - MRSA ... Centers for Disease Control and Prevention website. Methicillin-resistant Staphylococcus aureus (MRSA). www.cdc.gov/mrsa/index.html . Updated ...

Genetic diversity of Staphylococcus aureus in Buruli ulcer.

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Nana Ama Amissah

2015-02-01

Full Text Available Buruli ulcer (BU is a necrotizing skin disease caused by Mycobacterium ulcerans. Previous studies have shown that wounds of BU patients are colonized with M. ulcerans and several other microorganisms, including Staphylococcus aureus, which may interfere with wound healing. The present study was therefore aimed at investigating the diversity and topography of S. aureus colonizing BU patients during treatment.We investigated the presence, diversity, and spatio-temporal distribution of S. aureus in 30 confirmed BU patients from Ghana during treatment. S. aureus was isolated from nose and wound swabs, and by replica plating of wound dressings collected bi-weekly from patients. S. aureus isolates were characterized by multiple-locus variable number tandem repeat fingerprinting (MLVF and spa-typing, and antibiotic susceptibility was tested.Nineteen (63% of the 30 BU patients tested positive for S. aureus at least once during the sampling period, yielding 407 S. aureus isolates. Detailed analysis of 91 isolates grouped these isolates into 13 MLVF clusters and 13 spa-types. Five (26% S. aureus-positive BU patients carried the same S. aureus genotype in their anterior nares and wounds. S. aureus isolates from the wounds of seven (37% patients were distributed over two different MLVF clusters. Wounds of three (16% patients were colonized with isolates belonging to two different genotypes at the same time, and five (26% patients were colonized with different S. aureus types over time. Five (17% of the 30 included BU patients tested positive for methicillin-resistant S. aureus (MRSA.The present study showed that the wounds of many BU patients were contaminated with S. aureus, and that many BU patients from the different communities carried the same S. aureus genotype during treatment. This calls for improved wound care and hygiene.

Genetic diversity of Staphylococcus aureus in Buruli ulcer.

Science.gov (United States)

Amissah, Nana Ama; Glasner, Corinna; Ablordey, Anthony; Tetteh, Caitlin S; Kotey, Nana Konama; Prah, Isaac; van der Werf, Tjip S; Rossen, John W; van Dijl, Jan Maarten; Stienstra, Ymkje

2015-02-01

Buruli ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans. Previous studies have shown that wounds of BU patients are colonized with M. ulcerans and several other microorganisms, including Staphylococcus aureus, which may interfere with wound healing. The present study was therefore aimed at investigating the diversity and topography of S. aureus colonizing BU patients during treatment. We investigated the presence, diversity, and spatio-temporal distribution of S. aureus in 30 confirmed BU patients from Ghana during treatment. S. aureus was isolated from nose and wound swabs, and by replica plating of wound dressings collected bi-weekly from patients. S. aureus isolates were characterized by multiple-locus variable number tandem repeat fingerprinting (MLVF) and spa-typing, and antibiotic susceptibility was tested. Nineteen (63%) of the 30 BU patients tested positive for S. aureus at least once during the sampling period, yielding 407 S. aureus isolates. Detailed analysis of 91 isolates grouped these isolates into 13 MLVF clusters and 13 spa-types. Five (26%) S. aureus-positive BU patients carried the same S. aureus genotype in their anterior nares and wounds. S. aureus isolates from the wounds of seven (37%) patients were distributed over two different MLVF clusters. Wounds of three (16%) patients were colonized with isolates belonging to two different genotypes at the same time, and five (26%) patients were colonized with different S. aureus types over time. Five (17%) of the 30 included BU patients tested positive for methicillin-resistant S. aureus (MRSA). The present study showed that the wounds of many BU patients were contaminated with S. aureus, and that many BU patients from the different communities carried the same S. aureus genotype during treatment. This calls for improved wound care and hygiene.

A Case of Childhood Lichen Aureus

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Kim, Min Ji; Kim, Byung Yoon; Park, Kyung Chan; Youn, Sang Woong

2009-01-01

Lichen aureus is a rare type of chronic pigmented purpuric dermatosis. The eruptions consist of discrete or confluent golden to brownish lichenoid macules and papules, and are usually asymptomatic. Lichen aureus commonly occurs in young adults, but less frequently in children. We report the first case of multiple lichen aureus occurring in a Korean child.

La diversidad sexo-genérica: Un punto de vista evolutivo

OpenAIRE

Salín-Pascual, Rafael J.

2015-01-01

Introducción Hay un grupo de gente con una incoherencia entre el género y su sexo biológico (fenotipo) con el género de autopercepción. Las diferencias entre esta condición y la orientación sexual nos dan una serie de subtipos de género y de diversidad sexual: transexuales, travestis y transgéneros, homosexuales, heterosexuales, bisexuales y asexuales. Objetivo Revisar las evidencias que puedan apoyar si la diversidad de género y la orientación sexual son estrategias evolutivas. Método Se con...

A Review of Staphylococcal Cassette Chromosome mec (SCCmec) Types in Coagulase-Negative Staphylococci (CoNS) Species.

Science.gov (United States)

Saber, Huda; Jasni, Azmiza Syawani; Jamaluddin, Tengku Zetty Maztura Tengku; Ibrahim, Rosni

2017-10-01

Coagulase-negative staphylococci (CoNS) are considered low pathogenic organisms. However, they are progressively causing more serious infections with time because they have adapted well to various antibiotics owing to their ability to form biofilms. Few studies have been conducted on CoNS in both, hospital and community-acquired settings, especially in Malaysia. Thus, it is important to study their species and gene distributions. A mobile genetic element, staphylococcal cassette chromosome mec (SCC mec ), plays an important role in staphylococci pathogenesis. Among CoNS, SCC mec has been studied less frequently than Staphylococcus aureus (coagulase-positive staphylococci). A recent study (8) conducted in Malaysia successfully detected SCC mec type I to VIII as well as several new combination patterns in CoNS species, particularly Staphylococcus epidermidis . However, data are still limited, and further research is warranted. This paper provides a review on SCC mec types among CoNS species.

Epidemiology of drug resistance: The case of Staphylococcus aureus and coagulase-negative staphylococci infections Epidemiología de la resistencia bacteriana: el caso de Staphylococcus aureus y las infecciones Staphylococcus coagulasa negativas

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Ernesto Calderón-Jaimes

2002-04-01

Full Text Available Objective. To study the activity of several antibiotics against Staphylococcus spp. Material and Methods. The study included 1209 strains of Staphylococcus spp. from two institutions; Instituto Nacional de Pediatría (National Institute of Pediatrics and Hospital Infantil de México Federico Gómez (Mexico City Children's Hospital. Minimum Inhibitory Concentrations of all antibiotics were determined by the agar macrodilution technique and standard methods from the National Committee for Clinical Laboratory Standards. Results. Resistance of S. aureus was 14.2% and that of coagulase-negative staphylococci was 53.4%. The activity of different antibiotics is presented in detail. Conclusions. Surveillance of strains resistant to methicillin is necessary.Objetivo. Determinar la frecuencia de la resistencia a la meticilina y la actividad de varios antibióticos. Material y métodos. Se incluyeron 1 209 cepas de Staphylococcus spp. procedentes de pacientes del Instituto Nacional de Pediatría y del Hospital Infantil de México Federico Gómez. Se utilizó la técnica de dilución en placas con agar. El procedimiento e interpretación fueron acordes con lo establecido por el National Committee for Clinical Laboratory Standards. Resultados. La frecuencia de la resistencia de S. aureus fue de 14.2% y de 53.4% en los Staphylococcus coagulasa negativa. La actividad de otros antimicrobianos se presenta en el texto. Conclusiones. Es necesario vigilar continuamente la progresión de la resistencia de Staphylococcus spp. a la meticilina.

Antibiotic susceptibility pattern of staphylococcus aureus and methicillin-resistant staphylococcus aureus in a tertiary care hospital

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CP Bhatt

2014-04-01

Full Text Available Background: Methicillin resistant Staphylococcus aureushas emerged as one of the most important nosocomial pathogens. It invokes a tremendous financial burden and enhanced morbidity and mortality due to difficult to treat systemic infections.Aim of this study was to determine antibiotic susceptibility pattern of Staphylococcus aureus and Methicillin resistant Staphylococcus aureus. Materials and Methods: Different clinical specimens were collected and processed for routine culture and antibiotic sensitivity test by standard microbiology techniques. Results: Out of 1173 samples received for microbiological examination, 100 were found to be S. aureus with 19% cases were Methicillin resistant Staphylococcus aureus (MRSA. Fourteen MRSA were found from inpatient and 5 were from outpatient. MRSA was found higher in female than male and maximum number (31.5% was found in age group 0-10 years. Staphylococcus aureus was 100% sensitive to Vancomycin followed by Amikacin (90%, Gentamycin (83%, and tetracycline (81%. On urine isolates Nitrofurantoin(91.6% was drug of choice. All the isolates were resistant to Penicillin G. In case of Methicillin resistant Staphylococcus aureus showed 100% sensitive to Vancomycin followed by Amikacin (84.2%, Tetracycline (63.1%, Ciprofloxacin (42% and Gentamycin (36.8%. Among urine isolates Nitrofutantoin showed 87.5% sensitive followed by Norfloxacin (75%. Conclusion: Methicillin resistant Staphylococcus aureus was found 19% of Staphylococcus aureus isolates. It was most common in females, hospitalized patients and young age group. Vancomycin seems to be drug of choice followed by Amikacin. It would be helpful to formulating and monitoring the antibiotic policy and ensure proper empiric treatment. DOI: http://dx.doi.org/10.3126/jpn.v4i7.10297 Journal of Pathology of Nepal (2014 Vol. 4, 548-551   

Estudio de actinomicetos marinos aislados de la costa central del Perú y su actividad antibacteriana frente a Staphylococcus aureus Meticilina Resistentes y Enterococcus faecalis Vancomicina Resistentes Study of marine actinomycetes isolated from the central coast of Peru and their antibacterial activity against Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus faecalis

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Jorge León

2011-06-01

Full Text Available Objetivos. Determinar el potencial antimicrobiano de actinomicetos marinos frente a cepas S. aureus meticilino-resistentes (MRSA y E. faecalis vancomicina-resistentes (VRE. Materiales y métodos. En dos medios de cultivo se sembraron 29 cepas de actinomicetos aislados de sedimento marino. Se evaluó la capacidad inhibitoria mediante pruebas de antagonismo in vitro para MRSA y VRE. Se procesó los extractos orgánicos de tres actinomicetos seleccionados para determinar la Concentración Mínima Inhibitoria (CMI del compuesto activo. Resultados. La mayoría de los actinomicetos aislados correspondieron a un grupo homogéneo de blanco-grisáceos (62% con buen nivel de crecimiento en agar marino. Los porcentajes inhibitorios fueron superiores a 85% para ambos patógenos con halos de inhibición mayores a 69 y 78 mm de diámetro para MRSA y VRE respectivamente. Los extractos diclorometánicos de tres de los actinomicetos aislados (I-400A, B1-T61, M10-77 mostraron gran potencial inhibitorio de ambos patógenos, siendo M10-77 la cepa de actinomiceto de mayor actividad antibiótica frente a S. aureus ATCC 43300 resistente a meticilina y E. faecalis ATCC 51299 resistente a vancomicina con una Concentración Mínima Inhibitoria (CMI de 7,9 y 31,7 μg/ mL respectivamente. El análisis filogenético de la cepa M10- 77 presenta un 99% de similaridad con la especie marina Streptomyces erythrogriseus. Conclusiones. El sedimento marino de la costa central del Perú es fuente promisorio de cepas de actinomicetos con gran capacidad de producir compuestos bioactivos capaces de inhibir patógenos tipificados como multidrogo-resistentes tales como S. aureus meticilino resistentes y E. faecalis vancomicina resistentes.Objectives. To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA and vancomycin-resistant Enterococcus faecalis (VRE. Materials and

Análisis de transferencia horizontal de genes en ensayos de biorremediación con grasas recalcitrantes

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Catalina Rozo

2010-01-01

Full Text Available El empleo de microorganismos como herramienta para la mineralización de contaminantes orgánicos es una práctica que ha tomado mucha fuerza gracias a su eficiencia y bajo costo. La transferencia horizontal vía conjugación de genes es un requerimiento básico para optimizar procesos de biorremediación, por esta razón, además de conocer la diversidad metabólica es fundamental entender las interacciones que ocurren en una comunidad bacteriana para potenciar los procesos de biorremediación en campo. En este estudio se busca evaluar el potencial de transferencia horizontal (TH, tanto in vitro como en microcosmos de suelo, de aislamientos de bacterias obtenidas de un pasivo ambiental de grasas provenientes de la explotación carbonífera del Cerrejón. Inicialmente se agruparon los aislamientos de acuerdo con sus patrones de resistencia a antibióticos: ampicilina, cloramfenicol, gentamicina, tetraciclina y kanamicina. El potencial de TH de las cepas Vlf4, Ot3, Ot6, Pgt4, Blf11 y Vlf13 fue evaluado in vitro en medio sólido Luria-Bertani (LB donde se obtuvieron nuevos fenotipos a partir de los cruces Vlf13xOt6 y Pgt4xOt6, el nuevo fenotipo indica resistencia a los dos marcadores (ampR, kanR y su morfología sugiere que el receptor, en los dos casos, es la cepa Ot6. Los parentales Vlf13, Pgt4 y Ot6 fueron identificados por amplificación del gen RNAr 16S como Pseudomonas sp., Pseudomonas sp. y Chryseobacterium sp., respectivamente, y los transconjugantes como Chryseobacterium sp. Posteriormente, estos dos cruces fueron sometidos a ensayos de transferencia horizontal en microcosmos de suelos, donde se hizo evidente nuevamente la presencia de TH a una menor tasa. Los resultados obtenidos indican la posibilidad de un potencial de transferencia horizontal de genes entre los aislamientos seleccionados, dando lugar a la probabilidad de formular en futuros estudios un consorcio de bacterias que demuestran tener esta ventaja adaptativa.

Identification of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from burn patients by multiplex PCR.

Science.gov (United States)

Montazeri, Effat Abbasi; Khosravi, Azar Dokht; Jolodar, Abbas; Ghaderpanah, Mozhgan; Azarpira, Samireh

2015-05-01

Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) as important human pathogens are causes of nosocomial infections worldwide. Burn patients are at a higher risk of local and systemic infections with these microorganisms. A screening method for MRSA by using a multiplex polymerase chain reaction (PCR) targeting the 16S ribosomal RNA (rRNA), mecA, and nuc genes was developed. The aim of the present study was to investigate the potential of this PCR assay for the detection of MRSA strains in samples from burn patients. During an 11-month period, 230 isolates (53.11%) of Staphylococcus spp. were collected from burn patients. The isolates were identified as S. aureus by using standard culture and biochemical tests. DNA was extracted from bacterial colonies and multiplex PCR was used to detect MRSA and MRCoNS strains. Of the staphylococci isolates, 149 (64.9%) were identified as S. aureus and 81 (35.21%) were described as CoNS. Among the latter, 51 (62.97%) were reported to be MRCoNS. From the total S. aureus isolates, 132 (88.6%) were detected as MRSA and 17 (11.4%) were methicillin-susceptible S. aureus (MSSA). The presence of the mecA gene in all isolates was confirmed by using multiplex PCR as a gold standard method. This study presented a high MRSA rate in the region under investigation. The 16S rRNA-mecA-nuc multiplex PCR is a good tool for the rapid characterization of MRSA strains. This paper emphasizes the need for preventive measures and choosing effective antimicrobials against MRSA and MRCoNS infections in the burn units. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Staphylococcus aureus and hand eczema severity

DEFF Research Database (Denmark)

Haslund, P; Bangsgaard, N; Jarløv, J O

2009-01-01

BACKGROUND: The role of bacterial infections in hand eczema (HE) remains to be assessed. OBJECTIVES: To determine the prevalence of Staphylococcus aureus in patients with HE compared with controls, and to relate presence of S. aureus, subtypes and toxin production to severity of HE. METHODS......: Bacterial swabs were taken at three different visits from the hand and nose in 50 patients with HE and 50 controls. Staphylococcus aureus was subtyped by spa typing and assigned to clonal complexes (CCs), and isolates were tested for exotoxin-producing S. aureus strains. The Hand Eczema Severity Index...... and in the nose in all cases, and between visits in 90% of cases. Ten different CC types were identified, no association with severity was found, and toxin-producing strains were not found more frequently in patients with HE than in controls. CONCLUSIONS: Staphylococcus aureus was present on hands in almost half...

METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA ...

African Journals Online (AJOL)

Nosocomial infections caused by methicillin-resistant strains of Staphylococcus aureus often pose therapeutic dilemma to the clinicians because of the multi resistant nature of these strains of Staphylococcus aureus. Outbreaks of both nosocomial and community acquired infections are also frequent and difficult to control.

Caracterización, por RAPD-PCR, de aislados de Pseudomonas aeruginosa obtenidos de pacientes con fibrosis quística RAPD-PCR characterization of Pseudomonas aeruginosa strains obtained from cystic fibrosis patients

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Maribel Ortiz-Herrera

2004-04-01

Full Text Available OBJETIVO: Caracterizar a las cepas de P aeruginosa aisladas de lavados broncoalveolares de pacientes con fibrosis quística a lo largo de un periodo de tres años. MATERIAL Y MÉTODOS: Estudio prospectivo, de seguimiento de una población de pacientes con fibrosis quística. Se utilizó la técnica de la amplificación del ADN empleando PCR con bajas condiciones de especificidad (Random amplified polymorphic DNA, RAPD-PCR para la amplificación del ADN de cepas de P aeruginosa aisladas de lavados broncoalveolares de cinco pacientes con fibrosis quística, provenientes del Servicio de Neumología y Cirugía del Tórax del Instituto Nacional de Pediatría de la Ciudad de México, en el periodo de junio de 1996 a junio de 2002; se establecieron los patrones de amplificación de cada aislamiento, lo que permitió la identificación precisa de todas las cepas aisladas y el estudio de la epidemiología de P aeruginosa en los pacientes seleccionados con dicha enfermedad. RESULTADOS: Se definieron 18 patrones de amplificación del ADN que permitieron identificar a cada cepa de P aeruginosa aislada en las diferentes muestras de lavado broncoalveolar; no se encontró relación entre el fenotipo de P aeruginosa (mucoide o no mucoide y el genotipo de cada aislamiento, ya que cepas con fenotipos distintos mostraron patrones de amplificación semejantes; en nuestros pacientes se identificaron cepas con patrones de amplificación distintos a partir de una misma muestra, lo que sugiere la presencia de infecciones simultáneas por más de una cepa de P aeruginosa; se demostró que dos hermanos con la enfermedad compartían cepas con genotipos semejantes, lo que sugiere una contaminación cruzada entre ambos, y se demostró el aislamiento de cepas de P aeruginosa con genotipos semejantes a lo largo de los periodos estudiados. CONCLUSIONES: La identificación mediante la caracterización genotípica de las cepas de P aeruginosa aisladas de los pacientes con

Complete Genome Sequence of the Quality Control Strain Staphylococcus aureus subsp. aureus ATCC 25923.

Science.gov (United States)

Treangen, Todd J; Maybank, Rosslyn A; Enke, Sana; Friss, Mary Beth; Diviak, Lynn F; Karaolis, David K R; Koren, Sergey; Ondov, Brian; Phillippy, Adam M; Bergman, Nicholas H; Rosovitz, M J

2014-11-06

Staphylococcus aureus subsp. aureus ATCC 25923 is commonly used as a control strain for susceptibility testing to antibiotics and as a quality control strain for commercial products. We present the completed genome sequence for the strain, consisting of the chromosome and a 27.5-kb plasmid. Copyright © 2014 Treangen et al.

Síndromes genéticos reconocibles en el período neonatal Genetic syndromes recognizable in the neonatal period

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Víctor L. Ruggieri

2009-01-01

Full Text Available La presencia de un cuadro neurológico neonatal asociado o no a dismorfias o a un fenotipo particular puede responder a diversas causas a Prenatales: infecciosas (Grupo TORCH, agentes tóxicos o teratogénicos (alcohol, cocaína, antiepilépticos, inhalantes como el tolueno, etc., defectos vasculares o anomalías genéticas b Perinatales: cuadros hipóxico isquémicos, infecciones o trastornos metabólicos, entre otros. En este trabajo analizaremos aquellas entidades de origen genético reconocibles en el período neonatal por su fenotipo, las cuales deben incluirse entre los diagnósticos diferenciales frente a un niño con compromiso neurológico. Con el objeto de facilitar el reconocimiento de estas entidades las dividiremos de acuerdo al fenotipo más destacado u orientador, presente en el momento del nacimiento dividiéndolas en 2 grandes grupos: 1 Génicas, en las que incluimos: Síndromes con facies características y malformaciones en los miembros; Síndromes de sobrecrecimiento; Síndromes con déficit del crecimiento prenatal; Síndromes neuro-ectodérmicos; Síndromes con facies características con compromiso ocular y Síndromes con facies características (incluyendo, en las que lo tienen, su número del MIM y 2 Cromosómicas (anomalías en los autosomas: de número; en mosaico; deleciones y anomalías en los cromosomas sexuales. El reconocimiento a través del fenotipo de encefalopatías congénitas de origen genético es de gran importancia ya que su identificación permitirá: Orientar estudios diagnósticos específicos; evitar prácticas cruentas y/o costosas, inútiles si el diagnóstico clínico es por sí orientador; proveer el adecuado asesoramiento genético familiar y controlar evolutivamente las posibles complicaciones.The presence of a neonatal neurological lesion associated or not with dysmorphism or with a particular phenotype can be caused by a prenatal infections (Group TORCH toxic or teratotoxic agents (alcohol

Una metodología para evaluar el comportamiento de interacción genotipo-intrambiente con fines de selección en cabras lecheras

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B. López

2004-01-01

Full Text Available Conocida la universalidad del componente de interacción genotipo ambiente en el modelo fenotípico, el cual incluye otros dos componentes: el genotipo con sus efectos aditivos, dominantes y epistáticos, y el componente ambiental con sus efectos permanentes y temporales; se hace evidente que la selección de individuos en un ambiente dado no garantiza que manifiesten el mismo comportamiento cuando el ambiente es diferente. Con los resultados de investigaciones preliminares efectuadas por los autores, se propone una metodología basada en el modelo de regresión lineal, capaz de medir los efectos de interacción genotipo-intrambiente (ambientes fisiológicos de la curva de lactación para su evaluación con fines de selección del comportamiento diferencial que manifiestan los genotipos ante diversas condiciones ambientales. Se utilizan los registros mensuales de la producción láctea anual de 14 cabras «Saanen» en su primera lactación y se compara el comportamiento de interacción genotipo ambiente entre ellas. Los valores α y β de cada recta (cabra, fueron estimados considerando la producción mensual de cada cabra (fenotipo como la variable dependiente y los efectos ecológicos estandarizados como la variable independiente. Se graficaron y proyectaron las rectas de regresión de cada cabra a ± dos desviaciones estándar de los efectos ecológicos en el eje de las abscisas, se comparan los coeficientes β mediante pruebas de hipótesis «t»; poniéndose de manifiesto los efectos de interacción genotipo ambiente entre cabras al demostrarse que las pendientes de las rectas son diferentes. En esta metodología los valores de β cercanos a cero indican que los genotipos son estables

Deleção 22q11.2 em pacientes com defeito cardíaco conotruncal e fenótipo da síndrome da deleção 22q11.2 Deleción 22q11.2 en pacientes con defecto cardiaco conotruncal y fenotipo del síndrome de la deleción 22q11.2 22q11.2 deletion in patients with conotruncal heart defect and del22q syndrome phenotype

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Sintia Iole Nogueira Belangero

2009-04-01

índrome de la delación 22q11.2. MÉTODOS: Se estudiaron a 29 pacientes por medio de citogenética clásica, por hibridación in situ fluorescente (FISH y también por técnicas moleculares. RESULTADOS: El análisis citogenético por medio de bandeo G reveló cariotipo normal en todos los pacientes, con excepción de uno, que presentó cariotipo 47,XX,+idic(22(q11.2. Con la utilización de técnicas moleculares, se observó la deleción en el 25% de los pacientes, todos portadores del fenotipo del síndrome de la deleción 22q11.2. En ningún de los casos, la deleción se heredó de los padres. La frecuencia de la deleción 22q11.2 en el grupo de pacientes portadores del espectro clínico de este síndrome resultó mayor que en el grupo de pacientes con cardiopatía conotruncal aislada. CONCLUSIÓN: La investigación de la presencia de deleción y su correlación con los datos clínicos de los pacientes pueden auxiliar los pacientes y sus familias a tener un mejor aconsejamiento genético, así como un seguimiento clínico más adecuado.BACKGROUND: The 22q11.2 deletion syndrome is the most frequent human microdeletion syndrome. The phenotype is highly variable, being characterized by conotruncal heart defect, facial dysmorphisms, velopharyngeal insufficiency, learning difficulties and mental retardation. OBJECTIVE: The objective of this study was to investigate the frequency of deletion 22q11.2 in a Brazilian sample of individuals with isolated conotruncal heart defect and 22q11.2 deletion syndrome phenotype. METHODS: Twenty-nine patients were studied by classical cytogenetics, by fluorescence in situ hybridization (FISH, and by molecular techniques. RESULTS: Cytogenetic analysis by G-banding revealed a normal karyotype in all patients except one who presented a 47,XX,+idic(22(q11.2 karyotype. Using molecular techniques, a deletion was observed in 25% of the patients, all exhibiting a 22q11.2 deletion syndrome phenotype. In none of the cases the deletion was inherited from

Antimicrobial resistant coagulase positive Staphylococcus aureus ...

African Journals Online (AJOL)

ADEYEYE

S. aureus is associated with many clinical syndromes including tenosynovitis, omphalitis, femoral head necrosis, .... Markey, 2008) where occurrence of multidrug ... Staphylococcus aureus isolates from bovine mastitis in. Denmark. Veterinary.

Diversity and evolution of blaZ from Staphylococcus aureus and coagulase-negative staphylococci

DEFF Research Database (Denmark)

Olsen, John E.; Christensen, Henrik; Aarestrup, Frank Møller

2006-01-01

and sequences retrieved from public databases were compared. A phylogenetic tree showed that blaZ exists in three evolutionary lines: one group was of plasmid origin, one group was of chromosomal origin and one intermediate group. Sixty-nine sequence types were demonstrated. They translated into 11 BlaZ protein...... types. The major types all contained strains of both human and bovine origin, and more than one Staphylococcus species, demonstrating a shared gene pool. In a comparison of S. aureus and CoNS obtained from five Danish cattle herds, the same type of blaZ was only detected in one case. Conclusions...

Transfer of Antibiotic Resistance in Staphylococcus aureus

DEFF Research Database (Denmark)

Haaber, Jakob; Penadés, José R; Ingmer, Hanne

2017-01-01

Staphylococcus aureus is a serious human pathogen with remarkable adaptive powers. Antibiotic-resistant clones rapidly emerge mainly by acquisition of antibiotic-resistance genes from other S. aureus strains or even from other genera. Transfer is mediated by a diverse complement of mobile genetic...... of plasmids that can be transferred by conjugation and the efficiency with which transduction occurs. Here, we review the main routes of antibiotic resistance gene transfer in S. aureus in the context of its biology as a human commensal and a life-threatening pathogen. Staphylococcus aureus cells...... are effective in exchanging mobile genetic elements, including antibiotic-resistance genes.During colonization or infection of host organisms, the exchange appears to be particularly effective.Bacteriophage-mediated transfer involves both transduction and autotransduction, which may enable lysogenic S. aureus...

Methicillin-Susceptible, Vancomycin-Resistant Staphylococcus aureus, Brazil

OpenAIRE

Panesso , Diana; Planet , Paul J.; Diaz , Lorena; Hugonnet , Jean-Emannuel; Tran , Truc T.; Narechania , Apurva; Munita , José M.; Rincon , Sandra; Carvajal , Lina P.; Reyes , Jinnethe; Londono , Alejandra; Smith , Hannah; Sebra , Robert; Deikus , Gintaras; Weinstock , George M

2015-01-01

International audience; We report characterization of a methicillin-susceptible, vancomycin-resistant bloodstream isolate of Staphylococcus aureus recovered from a patient in Brazil. Emergence of vancomycin resistance in methicillin-susceptible S. aureus would indicate that this resistance trait might be poised to disseminate more rapidly among S. aureus and represents a major public health threat.

The salience of relational experiences: linking childhood interpersonal adversity, attachment style, and the subclinical psychosis phenotype

OpenAIRE

Sheinbaum Frank, Tamara

2014-01-01

El objetivo principal de la presente tesis doctoral fue investigar el papel de la adversidad interpersonal en la infancia y los estilos de apego adulto con respecto a la esquizotipia y otros fenotipos del espectro esquizofrénico en población no clínica. El cuerpo de la tesis se compone de siete capítulos que abordan cuestiones relacionadas con la evaluación y validez de los estilos de apego y las dimensiones de esquizotipia, las asociaciones entre estos constructos y el potencial efecto media...

Astrocitoma subependimario de células gigantes asociado a complejo de esclerosis tuberosa: recomendaciones para el diagnóstico oportuno y tratamiento.

OpenAIRE

Matilde Ruiz; Sandra Sánchez; Alejandro Rea; Roberto Sanromán; Joao García; Antonio Bravo; Infante Cantú; Hugo Ceja; Ariadna González; María del Mar Sáez

2015-01-01

RESUMEN El complejo de esclerosis tuberosa es una enfermedad genética poco frecuente, autosómica dominante con fenotipo y expresión clínica muy variables. Se caracteriza por alteraciones en la migración, diferenciación y proliferación celulares con formación de múltiples tumores benignos llamados hamartomas, las cuales afectan principalmente piel, encéfalo, riñón, ojo, corazón y pulmón. Los astrocitomas subependimarios de células gigantes son tumores benignos de crecimien...

Grado de conocimiento de la Diabetes Mellitus en la población de barrio “Quijarro” en la provincia Cercado del Departamento de Cochabamba

OpenAIRE

Gary Alex Clavijo Vargas

2011-01-01

La diabetes Mellitus (DM) es una enfermedad crónica, comprende un grupo de trastornos metabólicos frecuentes, además comparten el fenotipo de hiperglucemia. Hay varios tipos de DM con interacción genética y ambiental.Generalmente se encuentra afectada la población con un desequilibrio en el consumo de glucosa, carbohidratos, etc.Se realizó un estudio sobre el conocimiento de Diabetes Mellitus en el Barrio de “Quijarro” en la provincia Cercado de la ciudad de Cochabamba, durante los meses de A...

Fibrosis endomiocárdica

OpenAIRE

María Juliana Rodríguez-González; Ángela M. Torres; Luis E. Echeverría

2017-01-01

Las miocardiopatías son trastornos intrínsecos del músculo cardíaco. Presentan fenotipos diferenciales que determinan su clasificación; estos son: dilatada, hipertrófica, restrictiva, displasia arritmogénica del ventrículo derecho y no clasificadas. Las miocardiopatías restrictivas se caracterizan por ventrículos de tamaño normal, con grosores de pared normales o ligeramente aumentados, paredes rígidas, disfunción diastólica severa y llenado restrictivo con presiones elevadas. Una de las f...

Remodelamiento ventricular izquierdo secundario al entrenamiento en jugadores de rugby

OpenAIRE

Ennis, Irene L.; Pinilla, Oscar Andrés; Escudero, Eduardo Manuel

2016-01-01

La actividad física en deportistas puede asociarse con adaptaciones eléctricas, estructurales y funcionales del miocardio que configuran el corazón de atleta. Las características de la sobrecarga de trabajo impuesta por la actividad deportiva son las principales responsables de este fenotipo. El rugby es un deporte con moderada carga isométrica y moderada a intensa carga dinámica, pudiendo estas condiciones variar según la posición del jugador en el campo [fowards (F) vs. backs (B)]. Este tra...

Novel Multiplex PCR Assay for Detection of Chlorhexidine-Quaternary Ammonium, Mupirocin, and Methicillin Resistance Genes, with Simultaneous Discrimination of Staphylococcus aureus from Coagulase-Negative Staphylococci.

Science.gov (United States)

McClure, Jo-Ann; Zaal DeLongchamp, Johanna; Conly, John M; Zhang, Kunyan

2017-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a clinically significant pathogen that is resistant to a wide variety of antibiotics and responsible for a large number of nosocomial infections worldwide. The Agency for Healthcare Research and Quality and the Centers for Disease Control and Prevention recently recommended the adoption of universal mupirocin-chlorhexidine decolonization of all admitted intensive care unit patients rather than MRSA screening with targeted treatments, which raises a serious concern about the selection of resistance to mupirocin and chlorhexidine in strains of staphylococci. Thus, a simple, rapid, and reliable approach is paramount in monitoring the prevalence of resistance to these agents. We developed a simple multiplex PCR assay capable of screening Staphylococcus isolates for the presence of antiseptic resistance genes for chlorhexidine and quaternary ammonium compounds, as well as mupirocin and methicillin resistance genes, while simultaneously discriminating S. aureus from coagulase-negative staphylococci (CoNS). The assay incorporates 7 PCR targets, including the Staphylococcus 16S rRNA gene (specifically detecting Staphylococcus spp.), nuc (distinguishing S. aureus from CoNS), mecA (distinguishing MRSA from methicillin-susceptible S. aureus ), mupA and mupB (identifying high-level mupirocin resistance), and qac and smr (identifying chlorhexidine and quaternary ammonium resistance). Our assay demonstrated 100% sensitivity, specificity, and accuracy in a total of 23 variant antiseptic- and/or antibiotic-resistant control strains. Further validation of our assay using 378 randomly selected and previously well-characterized local clinical isolates confirmed its feasibility and practicality. This may prove to be a useful tool for multidrug-resistant Staphylococcus monitoring in clinical laboratories, particularly in the wake of increased chlorhexidine and mupirocin treatments. Copyright © 2017 American Society for Microbiology.

Resistencia de Staphylococcus aureus a los antibióticos en un hospital de la orinoquia colombiana Antimicrobial resistance of Staphylococus aureus at a hospital from the Colombian Orinoquia

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Norton Pérez

2010-09-01

Full Text Available Introducción: El objetivo de este estudio de cohorte retrospectivo fue analizar la resistencia de Staphylococcus aureus a los antibióticos en el Hospital Departamental de Villavicencio, centro de mediana y alta complejidad, entre 2005 y 2009. Materiales y métodos: Se analizaron los resultados de los estudios microbiológicos de los pacientes con cultivo positivo para S. aureus. No se hizo ninguna intervención. La variable de estudio fue la resistencia a la meticilina y el desenlace, la resistencia a los antimicrobianos. Resultados: Se tamizaron 29.451 estudios de microbiología y se encontraron 976 aislamientos de S. aureus, los cuales se analizaron para determinar su resistencia a los antibióticos por el método de microdilución en caldo. El 49,6 % de ellos (484 fueron clasificados como resistentes a la meticilina; se encontró un mayor grado de resistencia múltiple, especialmente para gentamicina (25,0% Vs. 2,9%, ciprofloxacina (25,1% Vs.2,4%, clindamicina (29,4% Vs.4,1% y eritromicina (31,0% Vs.1,7%, y menor, para trimetoprim/sulfametoxazol (11,8% Vs.4,1%. Aunque era de esperarse que la resistencia simultánea para la vancomicina fuera muy baja, se encontraron algunas cepas intermedias y resistentes, pero este resultado no se puede analizar adecuadamente debido a que estas cepas no se remitieron a un laboratorio de referencia para pruebas de confirmación. La resistencia a la tetraciclina, aun en las cepas sensibles a la meticilina, fue alta. No se identificó ninguna cepa resistente al linezolid. No se realizaron estudios para evaluar la resistencia a la tigeciclina. Conclusiones: La resistencia de S. aureus a la meticilina es frecuente también en esta institución hospitalaria de la orinoquia colombiana. La resistencia múltiple es mayor en S. aureus resistente a la meticilina, especialmente a la gentamicina, la ciprofloxacina y la clindamicina. Cuando S. aureus es sensible a la meticilina, también se observa un alto grado de

Evaluación de la efectividad de distintas formulaciones de jabón con extracto de Hypericum mexicanum L.

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Diana Carolina Corzo-Barragán

2017-06-01

Full Text Available Con el objetivo de evaluar la efectividad de distintas formulaciones de jabón líquido y sólido con extracto etanólico de Hypericum mexicanum L., se llevó a cabo una prueba de manipuladores. El recuento microbiano permitió analizar la efectividad en cada uno de los tratamientos evaluados, encontrando que el jabón líquido y sólido en concentración del 0,1% de extracto es el más efectivo; sin embargo, no existen diferencias significativas entre la concentración de extracto (0,1 – 0,2% y el control (jabón comercial. Por otro lado, usando el método de difusión en disco, se evaluó la actividad antimicrobiana de los distintos tratamientos, frente a (Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis y Pseudomonas aeruginosa, con lo cual se determinó que: 1 el jabón líquido en concentración de 0,1% y 0,2% de extracto vegetal y el jabón comercial inhiben el crecimiento de Escherichia coli; 2 todos los tratamientos presentaron inhibición frente a Staphylococcus aureus, exceptuando el de uso comercial y el sólido con extracto vegetal al 0,1%; 3 para  Staphylococcus epidermidis, se presentó una inhibición del jabón sólido y líquido sin extracto y del jabón líquido con extracto vegetal al 0, 2%; 4 en la evaluación de Pseudomonas aeruginosa, se observó inhibición del jabón líquido con concentración de extracto del 0,1% y 0,2% y del jabón comercial.

[Carriage of Staphylococcus aureus among food service workers].

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Alarcón-Lavín, María Paula; Oyarzo, Carolina; Escudero, Carlos; Cerda-Leal, Fabiola; Valenzuela, Francisco J

2017-12-01

Background Staphylococcus aureus produces 11 serotypes of endotoxins that may cause food poisoning. Aim To determine the prevalence of type A enterotoxigenic Staphylococcus aureus carriage among food service workers in Chillan, Chile. Material and Methods Pharyngeal swabs were obtained from 100 food service workers and were cultured in Agar plates. After identifying the presence of Staphylococcus aureus, DNA was extracted to identify type A toxin by conventional PCR. Results Thirty eight percent of samples were colonized with Staphylococcus aureus. Among these, 26% were toxin A producers. Conclusions Half of the sampled workers carried Staphylococcus aureus and a quarter of these produced type A enterotoxin.

Petrifilm rapid S. aureus Count Plate method for rapid enumeration of Staphylococcus aureus in selected foods: collaborative study.

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Silbernagel, K M; Lindberg, K G

2001-01-01

A rehydratable dry-film plating method for Staphylococcus aureus in foods, the 3M Petrifilm Rapid S. aureus Count Plate method, was compared with AOAC Official Method 975.55 (Staphylococcus aureus in Foods). Nine foods-instant nonfat dried milk, dry seasoned vegetable coating, frozen hash browns, frozen cooked chicken patty, frozen ground raw pork, shredded cheddar cheese, fresh green beans, pasta filled with beef and cheese, and egg custard-were analyzed for S. aureus by 13 collaborating laboratories. For each food tested, the collaborators received 8 blind test samples consisting of a control sample and 3 levels of inoculated test sample, each in duplicate. The mean log counts for the methods were comparable for pasta filled with beef and cheese; frozen hash browns; cooked chicken patty; egg custard; frozen ground raw pork; and instant nonfat dried milk. The repeatability and reproducibility variances of the Petrifilm Rapid S. aureus Count Plate method were similar to those of the standard method.

Molecular Characterization of Endocarditis-Associated Staphylococcus aureus

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Nethercott, Cara; Mabbett, Amanda N.; Totsika, Makrina; Peters, Paul; Ortiz, Juan C.; Nimmo, Graeme R.; Coombs, Geoffrey W.

2013-01-01

Infective endocarditis (IE) is a life-threatening infection of the heart endothelium and valves. Staphylococcus aureus is a predominant cause of severe IE and is frequently associated with infections in health care settings and device-related infections. Multilocus sequence typing (MLST), spa typing, and virulence gene microarrays are frequently used to classify S. aureus clinical isolates. This study examined the utility of these typing tools to investigate S. aureus epidemiology associated with IE. Ninety-seven S. aureus isolates were collected from patients diagnosed with (i) IE, (ii) bloodstream infection related to medical devices, (iii) bloodstream infection not related to medical devices, and (iv) skin or soft-tissue infections. The MLST clonal complex (CC) for each isolate was determined and compared to the CCs of members of the S. aureus population by eBURST analysis. The spa type of all isolates was also determined. A null model was used to determine correlations of IE with CC and spa type. DNA microarray analysis was performed, and a permutational analysis of multivariate variance (PERMANOVA) and principal coordinates analysis were conducted to identify genotypic differences between IE and non-IE strains. CC12, CC20, and spa type t160 were significantly associated with IE S. aureus. A subset of virulence-associated genes and alleles, including genes encoding staphylococcal superantigen-like proteins, fibrinogen-binding protein, and a leukocidin subunit, also significantly correlated with IE isolates. MLST, spa typing, and microarray analysis are promising tools for monitoring S. aureus epidemiology associated with IE. Further research to determine a role for the S. aureus IE-associated virulence genes identified in this study is warranted. PMID:23616460

Molecular characterization of endocarditis-associated Staphylococcus aureus.

Science.gov (United States)

Nethercott, Cara; Mabbett, Amanda N; Totsika, Makrina; Peters, Paul; Ortiz, Juan C; Nimmo, Graeme R; Coombs, Geoffrey W; Walker, Mark J; Schembri, Mark A

2013-07-01

Infective endocarditis (IE) is a life-threatening infection of the heart endothelium and valves. Staphylococcus aureus is a predominant cause of severe IE and is frequently associated with infections in health care settings and device-related infections. Multilocus sequence typing (MLST), spa typing, and virulence gene microarrays are frequently used to classify S. aureus clinical isolates. This study examined the utility of these typing tools to investigate S. aureus epidemiology associated with IE. Ninety-seven S. aureus isolates were collected from patients diagnosed with (i) IE, (ii) bloodstream infection related to medical devices, (iii) bloodstream infection not related to medical devices, and (iv) skin or soft-tissue infections. The MLST clonal complex (CC) for each isolate was determined and compared to the CCs of members of the S. aureus population by eBURST analysis. The spa type of all isolates was also determined. A null model was used to determine correlations of IE with CC and spa type. DNA microarray analysis was performed, and a permutational analysis of multivariate variance (PERMANOVA) and principal coordinates analysis were conducted to identify genotypic differences between IE and non-IE strains. CC12, CC20, and spa type t160 were significantly associated with IE S. aureus. A subset of virulence-associated genes and alleles, including genes encoding staphylococcal superantigen-like proteins, fibrinogen-binding protein, and a leukocidin subunit, also significantly correlated with IE isolates. MLST, spa typing, and microarray analysis are promising tools for monitoring S. aureus epidemiology associated with IE. Further research to determine a role for the S. aureus IE-associated virulence genes identified in this study is warranted.

Perfil fenotípico e genotípico de Staphylococcus aureus isolados de estudantes de enfermagem, 2008 Perfil fenotípico y genotípico del Staphylococcus aureus aislados de estudiantes de enfermería, 2008 Phenotypic and genotypic profile of Staphylococcus aureus isolated in nursing students, 2008

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Suelen Teixeira Faria

2011-01-01

Full Text Available OBJETIVO: Verificar a prevalência de carreamento nasal, perfil fenotípico e genotípico de S. aureus isolados de estudantes de enfermagem. MÉTODOS: Estudo transversal, com população composta por 101 alunos, cursando as três primeiras séries do curso de graduação em Enfermagem no ano de 2008. S. aureus foi isolado de material biológico obtido dos vestíbulos nasais através de swab. A susceptibilidade à oxacilina e vancomicina foi determinada pelo teste de concentração inibitória mínima. A presença do gene MecA foi determinada pelo teste de reação em cadeia da polimerase. RESULTADOS: Verificou-se 90,1% de positividade para S. aureus. A frequência de resistência à oxacilina foi de 9,8% e todas as amostras foram sensíveis à vancomicina. A oito amostras resistentes À oxacilina apresentaram o gene MecA. CONCLUSÃO: A prevalência foi elevada. A resistência à oxacilna foi expressiva e todas as amostras foram sensíveis à vancomicina. As amostras resistentes à oxacilina carreavam o gene MecA.OBJETIVO: Verificar la prevalencia de transporte nasal, perfil fenotípico y genotípico de S. aureus aislados de estudiantes de enfermería. MÉTODOS: Estudio transversal, con población compuesta por 101 alumnos, cursando las tres primeras series del Pregrado en Enfermería en el año 2008. El S. aureus fue aislado del material biológico obtenido de los vestíbulos nasales a través de swab. La susceptibilidad a la oxacilina y vancomicina fue determinada por el test de concentración inhibitoria mínima. La presencia del gen MecA fue determinada por el test de reacción en cadena de la polimerasa. RESULTADOS: Se verificó el 90,1% de positividad para el S. aureus. La frecuencia de resistencia a la oxacilina fue de 9,8% y todas las muestras fueron sensibles a la vancomicina. Las ocho muestras resistentes a la oxacilina presentaron el gen MecA. CONCLUSION: La prevalencia fue elevada. La resistencia a la oxacilina fue expresiva y todas

Subinhibitory quinupristin/dalfopristin attenuates virulence of Staphylococcus aureus.

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Koszczol, Carmen; Bernardo, Katussevani; Krönke, Martin; Krut, Oleg

2006-09-01

The semi-synthetic streptogramin quinupristin/dalfopristin antibiotic exerts potent bactericidal activity against Staphylococcus aureus. We investigated whether, like other bactericidal antibiotics used at subinhibitory concentrations, quinupristin/dalfopristin enhances release of toxins by Gram-positive cocci. The activity of quinupristin/dalfopristin on exotoxin release by S. aureus was investigated by 2D SDS-PAGE combined with MALDI-TOF/MS analysis and by western blotting. We show that quinupristin/dalfopristin at subinhibitory concentrations reduces the release of S. aureus factors that induce tumour necrosis factor secretion in macrophages. Furthermore, quinupristin/dalfopristin but not linezolid attenuated S. aureus-mediated killing of infected host cells. When added to S. aureus cultures at different stages of bacterial growth, quinupristin/dalfopristin reduced in a dose-dependent manner the release of specific virulence factors (e.g. autolysin, protein A, alpha- and beta-haemolysins, lipases). In contrast, other presumably non-toxic exoproteins remained unchanged. The results of the present study suggest that subinhibitory quinupristin/dalfopristin inhibits virulence factor release by S. aureus, which might be especially helpful for the treatment of S. aureus infections, where both bactericidal as well as anti-toxin activity may be advantageous.

Staphylococcus aureus and healthcare-associated infections

NARCIS (Netherlands)

Ekkelenkamp, M.B.

2011-01-01

Many medical procedures breach or suppress patients’ natural defences, leaving them vulnerable to infections which would not occur in healthy humans: “healthcare-associated infections”. Healthcare-associated infections caused by the bacterium Staphylococcus aureus (S. aureus) are probably the most

Detección y expresión de superantígenos y de resistencia antimicrobiana en aislamientos obtenidos de mujeres portadoras de Staphylococcus aureus que cuidan y alimentan niños.

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Guaca-González, Yina Marcela; Flórez-Restrepo, Gladys Fernanda; Moncayo-Ortíz, José Ignacio; Santacruz-Ibarra, Jorge; Álvarez-Aldana, Adalucy

2018-03-15

Introducción. Staphylococcus aureus coloniza mucosas y piel, y causa graves infecciones en el hombre y los animales. Es importante establecer el estatus de portadoras de cepas enterotoxigénicas de este microorganismo en manipuladoras de alimentos, con el fin de prevenir intoxicaciones alimentarias.Objetivo. Establecer las correlaciones entre los genes de enterotoxinas clásicas, el gen tsst-1, la producción de toxinas en cultivo y la resistencia antimicrobiana en aislamientos de S. aureus provenientes de manipuladoras de alimentos que cuidan niños en sus comunidades.Materiales y métodos. Se cultivaron muestras de las fosas nasales y las yemas de los dedos de las manos, y se identificó S. aureus empleando las pruebas de rutina y métodos automatizados. La extracción de ADN se hizo mediante el método de bromuro de cetil-trimetil-amonio (Cetyl-Trimethyl-Ammonium Bromide, CTAB) modificado. Para la detección de superantígenos se emplearon pruebas de reacción en cadena de la polimerasa (PCR) simple y múltiple, y para la de toxinas, estuches comerciales.Resultados. Se encontró que el 22,0 % de los aislamientos correspondía a portadoras de S. aureus: 17,0 % en los aislamientos de fosas nasales; 5,0 % en los de las manos y 6,7 % simultáneamente en los dos sitios. La prevalencia de superantígenos fue de 73,7 %. El genotipo más frecuente fue el seatsst-1, con 10,0 %. La resistencia a un solo antibiótico fue de 74,7 % y, a cuatro antibióticos, de 3,2 %; de los aislamientos, el 93,7 % correspondía a cepas productoras de betalactamasas. La detección de genes clásicos y de tsst-1 mediante PCR fue de 48,4 % y la de toxinas en el sobrenadante, de 42,1 %,con una correlación de 95,7 %. Las mayores correlaciones se establecieron entre las toxinas TSST-1 (22/22) y SEA (17/18). La correlación del gen tsst-1 con la proteína y la resistencia fue de 100 %. Todos los aislamientos con el genotipo sea-tsst-1 t fueron resistentes y productores de las toxinas

The sensitivity status of community-acquired Staphylococcus aureus ...

African Journals Online (AJOL)

Community acquired Staphylococcus aureus was isolated from various infectious sites in two private laboratories in Kano-city, Nigeria. A total of 247 (11%) Staphylococcu aureus isolates were recovered from all infectious sites except cerebro-spinal fluid. The least Staphylococcus aureus isolates were found in urine ...

Molecular Characterization of Endocarditis-Associated Staphylococcus aureus

OpenAIRE

Nethercott, Cara; Mabbett, Amanda N.; Totsika, Makrina; Peters, Paul; Ortiz, Juan C.; Nimmo, Graeme R.; Coombs, Geoffrey W.; Walker, Mark J.; Schembri, Mark A.

2013-01-01

Infective endocarditis (IE) is a life-threatening infection of the heart endothelium and valves. Staphylococcus aureus is a predominant cause of severe IE and is frequently associated with infections in health care settings and device-related infections. Multilocus sequence typing (MLST), spa typing, and virulence gene microarrays are frequently used to classify S. aureus clinical isolates. This study examined the utility of these typing tools to investigate S. aureus epidemiology associated ...

Diseño de dos metodologías moleculares para la rápida identificación de aislamientos de Staphylococcus aureus resistente a meticilina asociados a la comunidad en Colombia

OpenAIRE

Javier Antonio Escobar; Ingrid Tatiana Gómez; Martha Johanna Murillo; Betsy Esperanza Castro; Bibiana Chavarro; Ricaurte Alejandro Márquez; Natasha Vanegas

2012-01-01

Introducción. Los aislamientos de Staphylococcus aureus resistente a la meticilina asociado a la comunidad (SARM-AC), están aumentando la frecuencia de infecciones en personas sanas de la comunidad y en pacientes hospitalizados. En Colombia y en la región andina estos aislamientos tienen un componente genético relacionado con el clon pandémico USA300. Objetivo. Diseñar y estandarizar dos metodologías para la diferenciación rápida de aislamientos colombianos de S. aureus resistente a la me...

Staphylococcus aureus Central Nervous System Infections in Children.

Science.gov (United States)

Vallejo, Jesus G; Cain, Alexandra N; Mason, Edward O; Kaplan, Sheldon L; Hultén, Kristina G

2017-10-01

Central nervous system (CNS) infections caused by Staphylococcus aureus are uncommon in pediatric patients. We review the epidemiology, clinical features and treatment in 68 patients with a S. aureus CNS infection evaluated at Texas Children's Hospital. Cases of CNS infection in children with positive cerebrospinal fluid cultures or spinal epidural abscess (SEA) for S. aureus at Texas Children's Hospital from 2001 to 2013 were reviewed. Seventy cases of S. aureus CNS infection occurred in 68 patients. Forty-nine cases (70%) were secondary to a CNS device, 5 (7.1%) were postoperative meningitis, 9 (12.8%) were hematogenous meningitis and 7 (10%) were SEAs. Forty-seven (67.2%) were caused by methicillin-sensitive S. aureus (MSSA) and 23 (32.8%) by methicillin-resistant S. aureus (MRSA). Community-acquired infections were more often caused by MRSA that was clone USA300/pvl. Most patients were treated with nafcillin (MSSA) or vancomycin (MRSA) with or without rifampin. Among patients with MRSA infection, 50% had a serum vancomycin trough obtained with the median level being 10.6 μg/mL (range: 5.4-15.7 μg/mL). Only 1 death was associated with S. aureus infection. The epidemiology of invasive of S. aureus infections continues to evolve with MSSA accounting for most of the infections in this series. The majority of cases were associated with neurosurgical procedures; however, hematogenous S. aureus meningitis and SEA occurred as community-acquired infections in patients without predisposing factors. Patients with MRSA CNS infections had a favorable response to vancomycin, but the beneficial effect of combination therapy or targeting vancomycin trough concentrations of 15-20 μg/mL remains unclear.

The human nasal microbiota and Staphylococcus aureus carriage.

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Daniel N Frank

Full Text Available BACKGROUND: Colonization of humans with Staphylococcus aureus is a critical prerequisite of subsequent clinical infection of the skin, blood, lung, heart and other deep tissues. S. aureus persistently or intermittently colonizes the nares of approximately 50% of healthy adults, whereas approximately 50% of the general population is rarely or never colonized by this pathogen. Because microbial consortia within the nasal cavity may be an important determinant of S. aureus colonization we determined the composition and dynamics of the nasal microbiota and correlated specific microorganisms with S. aureus colonization. METHODOLOGY/PRINCIPAL FINDINGS: Nasal specimens were collected longitudinally from five healthy adults and a cross-section of hospitalized patients (26 S. aureus carriers and 16 non-carriers. Culture-independent analysis of 16S rRNA sequences revealed that the nasal microbiota of healthy subjects consists primarily of members of the phylum Actinobacteria (e.g., Propionibacterium spp. and Corynebacterium spp., with proportionally less representation of other phyla, including Firmicutes (e.g., Staphylococcus spp. and Proteobacteria (e.g. Enterobacter spp. In contrast, inpatient nasal microbiotas were enriched in S. aureus or Staphylococcus epidermidis and diminished in several actinobacterial groups, most notably Propionibacterium acnes. Moreover, within the inpatient population S. aureus colonization was negatively correlated with the abundances of several microbial groups, including S. epidermidis (p = 0.004. CONCLUSIONS/SIGNIFICANCE: The nares environment is colonized by a temporally stable microbiota that is distinct from other regions of the integument. Negative association between S. aureus, S. epidermidis, and other groups suggests microbial competition during colonization of the nares, a finding that could be exploited to limit S. aureus colonization.

Staphylococcus aureus shifts towards commensalism in response to Corynebacterium species

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Matthew M Ramsey

2016-08-01

Full Text Available Staphylococcus aureus–human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe-microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence towards a commensal state when exposed to commensal Corynebacterium species.

Dermoscopy of lichen aureus Dermatoscopia do liquen aureus

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Poliana Santin Portela

2013-04-01

Full Text Available Lichen aureus (also called "lichen purpuricus" is an uncommon subtype of pigmented purpuric dermatosis. Clinically characterized by rust macules, papules or plaques, it is a chronic disease which more often affects young adults and is localized mainly on the lower extremities. The diagnosis is made on the basis of clinical and histopathological features. Dermoscopy findings are useful to confirm clinical diagnosis.O líquen aureus (também denominado "liquen purpuricus" é um subtipo pouco comum entre as dermatoses purpúricas pigmentadas. Clinicamente caracterizado por máculas, pápulas ou placas de coloração ferruginosa, é doença crônica, que acomete mais frequentemente adultos jovens e localiza-se principalmente nos membros inferiores. O diagnóstico pode ser feito a partir das características clínicas e histopatológicas, sendo os achados dermatoscópicos úteis para corroborar o diagnóstico clínico.

Population structure of Staphylococcus aureus in China

OpenAIRE

Yan, Xiaomei

2015-01-01

The present PhD research was aimed at analysing the population structure of Staphylococcus aureus in China. Between 2000 and 2005 we found that patients from a single Chinese hospital showed increasing trends in antimicrobial resistance. Among methicillin-resistant S. aureus (MRSA), resistance against rifampicin doubled to 68%. Staphylococcal food poisoning (SFP) is frequent in China. Two predominant S. aureus lineages, ST6 and ST943, were identified causing outbreaks of SFP in Southern China...

Methicillin-resistant staphylococcus aureus isolates in a hospital of shanghai.

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Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

2017-01-24

Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses' hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention.

Bacteriemia en pacientes internados con celulitis

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Juan S. Lasa

2012-08-01

Full Text Available La celulitis es una inflamación aguda de la dermis y tejido celular subcutáneo de causa bacteriana, que generalmente complica a heridas, úlceras y dermatosis, aunque de manera frecuente no existe sitio de entrada. Se recomienda la realización de cultivo de punción de piel y partes blandas (PPB. Los hemocultivos raramente dan resultados positivos. El objetivo de este trabajo fue determinar la prevalencia de bacteriemia en pacientes internados en nuestra institución con diagnóstico de celulitis. Se analizaron retrospectivamente los registros clínicos de los pacientes con este diagnóstico al ingreso entre junio de 2007 y marzo de 2010. Se evaluaron los datos poblacionales, presencia de comorbilidades, y resultados de los cultivos. En ese período, se internaron 140 pacientes con diagnóstico de celulitis y a todos ellos se les realizó hemocultivo y cultivos de PPB. Setenta y cuatro eran varones (52.8%. La edad promedio: 47.5 ± 19.7 años (rango 16-94. El 40% tuvo cultivos positivos de PPB, en los que el Staphylococcus aureus meticilino resistente (SAMR fue el germen más frecuentemente aislado (35.7%; la prevalencia de bacteriemia fue del 8.6%, en donde el germen más frecuente fue Streptoccocus Beta hemolítico, grupo G (33% del total de hemocultivos positivos. La bacteriemia se asoció significativamente a mayor estadía hospitalaria (10.5 ± 8.9 vs. 4.9 ± 6, p = 0.004. Se asoció con mayor riesgo de hemocultivo positivo a ser diabético, tener cultivo de PPB positivo, consumo de alcohol y/o enfermedad pulmonar obstructiva crónica.

Prevalence and characteristics of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus nasal colonization among a community-based diabetes population in Foshan, China.

Science.gov (United States)

Lin, Jialing; Xu, Ping; Peng, Yang; Lin, Dongxin; Ou, Qianting; Zhang, Ting; Bai, Chan; Ye, Xiaohua; Zhou, Junli; Yao, Zhenjiang

2017-05-01

Evidence suggests that diabetes might cause an increase in colonization of Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) in community settings. We carried out a cross-sectional study to determine the prevalence and influencing factors of S. aureus and MRSA nasal colonization among a community-based diabetes population, and to identify the characteristics of the isolated strains. A total of 956 participants from 11 community settings were included in the study. Of the 529 diabetes participants, 46 were colonized with S. aureus and 22 were colonized with MRSA. Of the 427 non-diabetes participants, 25 were colonized with S. aureus and 12 were colonized with MRSA. Men (odds ratio 0.45, 95% confidence interval 0.20-0.99, P = 0.047) were less likely to have S. aureus nasal colonization, and those with well-controlled blood glucose (odds ratio 2.04, 95% confidence interval 1.01-4.13, P = 0.047) among the diabetes population were more likely to have S. aureus nasal colonization. The proportion of multidrug-resistant S. aureus strains in the diabetes population (52.17%) was higher than that in the non-diabetes population (28.00%; χ 2 = 3.848, P = 0.050). The most common clonal complex type and Staphylococcal chromosome cassette mec type of MRSA in diabetes population was clonal complex 5 (40.91%) and type IV (27.27%), respectively. The proportion of Panton-Valentine leukocidin gene in MRSA strains was 17.65%. There was great sequence type diversity in MRSA strains. The prevalence of MRSA in the community-based diabetes population was moderate, and the high proportions of multidrug-resistant S. aureus strains and diverse molecular characteristics in the diabetes population should be noticed. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Antimicrobial resistance and mecA characterization of methicillin-susceptible S. aureus and non-S. aureus of beef meat origin in Egypt

Directory of Open Access Journals (Sweden)

Kamelia Mahmoud Osman

2016-02-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA have been found in various farm animal species throughout the world. Yet, methicillin-susceptible S. aureus (MSSA, methicillin-susceptible non-S. aureus (MS-NSA and methicillin-resistant non-S. aureus (MR-NSA were not investigated. Therefore, we persued to determine the diversity in theirphenotypic virulence assay, phenotypic antimicrobial resistance profile and molecular characterisation in one of the food chains in Egypt. Samples were collected during 2013 from beef meat at retail. Twenty seven isolates comprising five species (S. hyicus, S. aureus, S. schleiferi subsp. coagulans, S. intermedius and S. lentus were characterized for their antibiotic resistance phenotypic profile and antibiotic resistance genes (mecA, cfr, gyrA, gyrB and grlA. Out of the 27 Staphylococcus isolates only one isolate was resistant to the 12 antibiotics representing nine classes. Raw beef meat sold across the Great Cairo zone, contains 66.7% of MRS, with highest prevalence was reported in S. aureus (66.7%, while the MRS non-S. aureus strains constituted 66.7% from which S. hyicus (60%, S. intermedius (33.3%, S. schleiferi subsp. coagulans (100% and S. lentus (100% were MRS. Seven S. aureus, six S. hyicus, four S. schleiferi subsp. coagulans, three S. intermedius and one S. lentus isolates although being resistant to oxacillin yet, 11/27 (40.7% carried the mecA gene. At the same time, the cfr gene was present in 2 of the nine S. aureus isolates, and totally undetectable in S. hyicus, S. schleiferi subsp. coagulans, S. intermedius and S. lentus. Although global researches largely focused into MRSA and MR-NSA in animals on pigs, the analysis of our results stipulates that buffaloes and cattle could be MRSA dispersers and that this theme is not specific to pigs. Detection of MSSA virulence determinants is a must, as although oxacillin resistance may be absent yet, the MSSA may carry the virulence determinants which could

Efecto antimicrobiano de extractos etanólicos de albahaca (Ocimum basilicum L. sobre el crecimiento de Staphylococcus aureus

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Julio Colivet

2011-12-01

Full Text Available La albahaca (Ocimum basilicum L. es una planta herbácea de la familia de las labiadas (Lamiaceae, muy común en Venezuela. En la presente investigación se evaluó la supervivencia de una cepa de Staphylococcus aureus por la acción antimicrobiana de extractos etanólicos de albahaca fresca y seca. Las muestras frescas fueron sometidas a homogeneización en licuadora. Para la obtención de las muestras secas se utilizó una estufa convencional a temperatura de 55 ºC x 28 horas. Los extractos se obtuvieron por destilación a presión reducida, temperatura de 45 ºC y empleando etanol como solvente. Posteriormente, se emplearon en medios de cultivo contentivos de S. aureus y se monitoreó el crecimiento del microorganismo en el tiempo, obteniéndose los parámetros de crecimiento a través del modelo de Baranyi y Roberts (1994. Los extractos frescos y secos produjeron efecto antimicrobiano sobre S. aureus a concentraciones de 5 y 10 %, afectando los parámetros de crecimiento de la bacteria, presentando diferencias estadísticamente significativas (p < 0,05 con respecto al grupo control.

Efecto antimicrobiano de extractos etanólicos de albahaca (Ocimum basilicum L. sobre el crecimiento de Staphylococcus aureus

Directory of Open Access Journals (Sweden)

Julio Colivet

2011-01-01

Full Text Available La albahaca (Ocimum basilicum L. es una planta herbácea de la familia de las labiadas (Lamiaceae, muy común en Venezuela. En la presente investigación se evaluó la supervivencia de una cepa de Staphylococcus aureus por la acción antimicrobiana de extractos etanólicos de albahaca fresca y seca. Las muestras frescas fueron sometidas a homogeneización en licuadora. Para la obtención de las muestras secas se utilizó una estufa convencional a temperatura de 55 ºC x 28 horas. Los extractos se obtuvieron por destilación a presión reducida, temperatura de 45 ºC y empleando etanol como solvente. Posteriormente, se emplearon en medios de cultivo contentivos de S. aureus y se monitoreó el crecimiento del microorganismo en el tiempo, obteniéndose los parámetros de crecimiento a través del modelo de Baranyi y Roberts (1994. Los extractos frescos y secos produjeron efecto antimicrobiano sobre S. aureus a concentraciones de 5 y 10 %, afectando los parámetros de crecimiento de la bacteria, presentando diferencias estadísticamente significativas (p < 0,05 con respecto al grupo control.

Lysionotin attenuates Staphylococcus aureus pathogenicity by inhibiting α-toxin expression.

Science.gov (United States)

Teng, Zihao; Shi, Dongxue; Liu, Huanyu; Shen, Ziying; Zha, Yonghong; Li, Wenhua; Deng, Xuming; Wang, Jianfeng

2017-09-01

α-Toxin, one of the best known pore-forming proteins produced by Staphylococcus aureus (S. aureus), is a critical virulence factor in multiple infections. The necessity of α-toxin for S. aureus pathogenicity suggests that this toxin is an important target for the development of a potential treatment strategy. In this study, we showed that lysionotin, a natural compound, can inhibit the hemolytic activity of culture supernatants by S. aureus by reducing α-toxin expression. Using real-time PCR analysis, we showed that transcription of hla (the gene encoding α-toxin) and agr (the locus regulating hla) was significantly inhibited by lysionotin. Lactate dehydrogenase and live/dead assays indicated that lysionotin effectively protected human alveolar epithelial cells against S. aureus, and in vivo studies also demonstrated that lysionotin can protect mice from pneumonia caused by S. aureus. These findings suggest that lysionotin is an efficient inhibitor of α-toxin expression and shows significant protection against S. aureus in vitro and in vivo. This study supports a potential strategy for the treatment of S. aureus infection by inhibiting the expression of virulence factors and indicates that lysionotin may be a potential treatment for S. aureus pneumonia.

Evolution of methicillin-resistant Staphylococcus aureus towards increasing resistance

DEFF Research Database (Denmark)

Strommenger, Birgit; Bartels, Mette Damkjær; Kurt, Kevin

2014-01-01

To elucidate the evolutionary history of Staphylococcus aureus clonal complex (CC) 8, which encompasses several globally distributed epidemic lineages, including hospital-associated methicillin-resistant S. aureus (MRSA) and the highly prevalent community-associated MRSA clone USA300.......To elucidate the evolutionary history of Staphylococcus aureus clonal complex (CC) 8, which encompasses several globally distributed epidemic lineages, including hospital-associated methicillin-resistant S. aureus (MRSA) and the highly prevalent community-associated MRSA clone USA300....

Nasal Staphylococcus aureus and methicillin-resistant Staphylococcus aureus carriage among college student athletes in northern Taiwan

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Hong-Kai Wang

2017-08-01

Full Text Available Of 259 college students in northern Taiwan surveyed, nasal carriage rate of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA was 22.4% and 1.54%, respectively and no significant difference was found between athlete students and non-athlete students. Three of four MRSA isolates belonged to sequence type 59, the endemic community clone.

Diagnóstico y tratamiento de los síndromes de sobreposición de hepatitis autoinmune

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O. Aguilar-Nájera

2015-04-01

En la actualidad, aún existe controversia acerca de si los síndromes de sobreposición son entidades diferentes o la presencia de 2 enfermedades coexistentes. Deben ser buscados en los pacientes con hepatitis autoinmune que tienen datos de colestasis ya que sabemos que su comportamiento tiende a ser más agresivo con mayores tasas de cirrosis y necesidad de trasplante hepático así como pobre respuesta al tratamiento, el cual debe ser dirigido al fenotipo principal. Hacen falta definiciones estandarizadas que permitan su estudio en ensayos clínicos controlados.

Factores de riesgo pre y postnatal asociados a disconectividad cerebral en trastornos mentales

OpenAIRE

Santillana Pérez, María

2017-01-01

La esquizofrenia es una enfermedad frecuente e incapacitante asociada con fenotipos psiquiátricos heterogéneos, la hipótesis predominante con respecto a trastornos psicóticos propone que una combinación de factores genéticos y / o ambientales, durante los períodos críticos de desarrollo del cerebro aumenta el riesgo de estas enfermedades. La exposición prenatal a patógenos infecciosos o estímulos inflamatorios es cada vez más reconocida por desempeñar un papel etiológico importante en los tra...

Control de la diferenciación celular in vitro en células HT-29 de cáncer colorectal

OpenAIRE

Mayo de las Casas, Clara de la Caridad

2005-01-01

La línea celular HT-29 M6 es una línea tumoral humana derivada de adenocarcinoma de colon, con capacidad de diferenciación in vitro hacia un fenotipo mucosecretor, obtenida por selección con 10-7 M y 10-6 M de metotrexato, en tratamientos sucesivos, de la línea parental indiferenciada HT-29 (Lesuffleur T, et al, 1990). Nosotros utilizamos esta línea celular como modelo para estudiar el proceso de diferenciación in vitro que ocurre de manera espontánea durante el crecimiento hacia confluencia....

Communications of Staphylococcus aureus and non-aureus Staphylococcus species from bovine intramammary infections and teat apex colonization

DEFF Research Database (Denmark)

Mahmmod, Yasser S.; Klaas, Ilka Christine; Svennesen, Line

2018-01-01

The role of non-aureus staphylococci (NAS) in the risk of acquisition of intramammary infections with Staphylococcus aureus is vague and still under debate. The objectives of this study were to (1) investigate the distribution patterns of NAS species from milk and teat skin in dairy herds with au...

Methicillin resistant Staphylococcus aureus in Ethiopia: a meta-analysis.

Science.gov (United States)

Eshetie, Setegn; Tarekegn, Fentahun; Moges, Feleke; Amsalu, Anteneh; Birhan, Wubet; Huruy, Kahsay

2016-11-21

The burden of methicillin resistant Staphylococcus aureus is a major public health concern worldwide; however the overall epidemiology of multidrug resistant strains is neither coordinated nor harmonized, particularly in developing countries including Ethiopia. Therefore, the aim of this meta-analysis was to assess the burden of methicillin resistant Staphylococcos aureus and its antibiotic resistance pattern in Ethiopia at large. PubMed, Google Scholar, and lancet databases were searched and a total of 20 studies have been selected for meta-analysis. Six authors have independently extracts data on the prevalence of methicillin resistant Staphylococcus aureus among clinical isolates of Staphylococcus aureus. Statistical analysis was achieved by using Open meta-analyst (version 3.13) and Comprehensive meta-analysis (version 3.3) softwares. The overall prevalence of methicillin resistant Staphylococcus aureus and its antibiotic resistance pattern were pooled by using the forest plot, table and figure with 95% CI. The pooled prevalence of methicillin resistant Staphylococcus aureus was 32.5% (95% CI, 24.1 to 40.9%). Moreover, methicillin resistant Staphylococcus aureus strains were found to be highly resistant to penicillin, ampicillin, erythromycin, and amoxicillin, with a pooled resistance ratio of 99.1, 98.1, 97.2 and 97.1%, respectively. On the other hand, comparably low levels of resistance ratio were noted to vancomycin, 5.3%. The overall burden of methicillin resistant Staphylococcus aureus is considerably high, besides these strains showed extreme resistance to penicillin, ampicillin, erythromycin and amoxicillin. In principle, appropriate use of antibiotics, applying safety precautions are the key to reduce the spread of multidrug resistant strains, methicillin resistant Staphylococcus aureus in particular.

Antibiotic susceptibility of Staphylococcus aureus in suppurative ...

African Journals Online (AJOL)

1299, p<0.05) and Methicillin resistance was confirmed by PCR. Conclusion: Staphylococcus aureus is highly prevalent and more resistant in inpatients. There is a higher risk of acquiring drug resistant staphylococcus aureus infection in ...

Memory Th1 Cells Are Protective in Invasive Staphylococcus aureus Infection

Science.gov (United States)

Lalor, Stephen J.; Leech, John M.; O’Keeffe, Kate M.; Mac Aogáin, Micheál; O’Halloran, Dara P.; Lacey, Keenan A.; Tavakol, Mehri; Hearnden, Claire H.; Fitzgerald-Hughes, Deirdre; Humphreys, Hilary; Fennell, Jérôme P.; van Wamel, Willem J.; Foster, Timothy J.; Geoghegan, Joan A.; Lavelle, Ed C.; Rogers, Thomas R.; McLoughlin, Rachel M.

2015-01-01

Mechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we demonstrated that prior exposure to S. aureus enhanced IFNγ responses upon subsequent infection, while adoptive transfer of S. aureus antigen-specific Th1 cells was protective in naïve mice. Translating these findings, we found that S. aureus antigen-specific Th1 cells were also significantly expanded during human S. aureus bloodstream infection (BSI). These Th1 cells were CD45RO+, indicative of a memory phenotype. Thus, exposure to S. aureus induces memory Th1 cells in mice and humans, identifying Th1 cells as potential S. aureus vaccine targets. Consequently, we developed a model vaccine comprising staphylococcal clumping factor A, which we demonstrate to be an effective human T cell antigen, combined with the Th1-driving adjuvant CpG. This novel Th1-inducing vaccine conferred significant protection during S. aureus infection in mice. This study notably advances our understanding of S. aureus cellular immunity, and demonstrates for the first time that a correlate of S. aureus protective immunity identified in mice may be relevant in humans. PMID:26539822

Memory Th1 Cells Are Protective in Invasive Staphylococcus aureus Infection.

LENUS (Irish Health Repository)

Brown, Aisling F

2015-01-01

Mechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we demonstrated that prior exposure to S. aureus enhanced IFNγ responses upon subsequent infection, while adoptive transfer of S. aureus antigen-specific Th1 cells was protective in naïve mice. Translating these findings, we found that S. aureus antigen-specific Th1 cells were also significantly expanded during human S. aureus bloodstream infection (BSI). These Th1 cells were CD45RO+, indicative of a memory phenotype. Thus, exposure to S. aureus induces memory Th1 cells in mice and humans, identifying Th1 cells as potential S. aureus vaccine targets. Consequently, we developed a model vaccine comprising staphylococcal clumping factor A, which we demonstrate to be an effective human T cell antigen, combined with the Th1-driving adjuvant CpG. This novel Th1-inducing vaccine conferred significant protection during S. aureus infection in mice. This study notably advances our understanding of S. aureus cellular immunity, and demonstrates for the first time that a correlate of S. aureus protective immunity identified in mice may be relevant in humans.

A prospective cohort study of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus carriage in neonates: the role of maternal carriage and phenotypic and molecular characteristics

Science.gov (United States)

Lin, Jialing; Wu, Chuanan; Yan, Chunrong; Ou, Qianting; Lin, Dongxin; Zhou, Junli; Ye, Xiaohua; Yao, Zhenjiang

2018-01-01

Background Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), in mothers can cause serious outcomes in neonates. We aimed to elucidate the associations of S. aureus and MRSA carriage between mothers and neonates. Methods A prospective cohort study was conducted between August and November 2015 in two hospitals in Shenzhen, China. Chinese pregnant women and their neonates who met the inclusion criteria were included in this study; samples and relevant information were collected. We assessed maternal–neonatal associations by using Poisson regression models. Results Overall, 1834 mothers and their neonates were included in this study. The prevalence of isolate carriage among the mothers was as follows: S. aureus (nasal, 25.8%; vaginal, 7.3%; and nasal and vaginal, 3.3%) and MRSA (nasal, 5.7%; vaginal, 1.7%; and nasal and vaginal, 0.5%). The incidences of S. aureus and MRSA carriage among neonates were 3.3% and 0.8%, respectively. Of the 21 maternal–neonatal pairs with S. aureus carriage, 14 were concordant pairs with the same phenotypic and molecular characteristics. After adjustment, the relative risks and 95% confidence intervals (CIs) between the S. aureus carriage of neonates and nasal S. aureus carriage, vaginal S. aureus carriage, and both nasal and vaginal S. aureus carriage of mothers were 2.8 (95% CI, 1.6–4.8), 7.1 (95% CI, 4.1–12.4), and 9.6 (95% CI, 4.2–22.4), respectively. Conclusion S. aureus carriage in mothers increases the risk for neonates. PMID:29731644

Edad y crecimiento de la mojarra Oreochromis aureus (Pisces: Cichlidae) en la Presa Sanalona, Sinaloa, México

OpenAIRE

Beltrán-Álvarez, Rigoberto; Sánchez-Palacios, Jesús; Valdez, Guadalupe L; Ortega-Salas, Armando A

2010-01-01

Oreochromis aureus es un importante recurso pesquero en el embalse, por lo cual se realizó un estudio sobre su edad y crecimiento desde noviembre del 2006 a septiembre del 2007. Se realizaron muestreos bimensuales con redes agalleras de varios tamaños de luz de malla, y también se colectaron peces de la captura comercial. Se midió la longitud total (Lt), el peso total (Pt), el sexo y la madurez gonádica. La edad se determinó mediante lecturas de marcas de crecimiento en escamas y su validació...

Staphylococcus aureus and community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in and around therapeutic whirlpools in college athletic training rooms.

Science.gov (United States)

Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A

2015-04-01

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Cross-sectional study. National Collegiate Athletic Association Division I university. Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F(2,238) = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses.

Human factor in Staphylococcus aureus nasal carriage

NARCIS (Netherlands)

J.L. Nouwen (Jan); H.A.M. Boelens (Hélène); A.F. van Belkum (Alex); H.A. Verbrugh (Henri)

2004-01-01

textabstractPersistent nasal carriers and noncarriers of Staphylococcus aureus were inoculated with a mixture of different S. aureus strains. The majority of noncarriers and nearly all persistent carriers returned to their original carrier state after artificial inoculation. Furthermore, the

Determinants of carriage of resistant Staphylococcus aureus among S. aureus carriers in the Indonesian population inside and outside hospitals

NARCIS (Netherlands)

E.S. Lestari (Endang Sri); D.O. Duerink (Offra); U. Hadi (Usman); J.A. Severin (Juliëtte); N.J.D. Nagelkerke (Nico); K. Kuntaman (Kuntaman); H. Wahjono (Hendro); W. Gardjito (Widjoseno); A. Soejoenoes (Ariawan); P. van den Broek (Peterhans); M. Keuter (Monique); I.C. Gyssens (Inge); H.A. Verbrugh (Henri)

2010-01-01

textabstractOBJECTIVES: To identify determinants of carriage of resistant Staphylococcus aureus in both hospitalized patients and individuals from the community in two urban centres in Indonesia. METHODS: Staphylococcus aureus cultures and data on recent antibiotic use, demographic, socioeconomic,

Staphylococcus aureus in the community: colonization versus infection.

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Maureen Miller

Full Text Available BACKGROUND: Antibiotic-resistant Staphylococcus aureus infections have increased dramatically in the community, yet S. aureus nasal colonization has remained stable. The objectives of this study were to determine if S. aureus colonization is a useful proxy measure to study disease transmission and infection in community settings, and to identify potential community reservoirs. METHODOLOGY/PRINCIPAL FINDINGS: Randomly selected households in Northern Manhattan, completed a structured social network questionnaire and provided nasal swabs that were typed by pulsed field gel electrophoresis to identify S. aureus colonizing strains. The main outcome measures were: 1 colonization with S. aureus; and 2 recent serious skin infection. Risk factor analyses were conducted at both the individual and the household levels; logistic regression models identified independent risks for household colonization and infection. RESULTS: 321 surveyed households contained 914 members. The S. aureus prevalence was 25% and MRSA was 0.4%. More than 40% of households were colonized. Recent antibiotic use was the only significant correlate for household colonization (p = .002. Seventy-eight (24% households reported serious skin infection. In contrast with colonization, five of the six risk factors that increased the risk of skin infection in the household at the univariate level remained independently significant in multivariable analysis: international travel, sports participation, surgery, antibiotic use and towel sharing. S. aureus colonization was not significantly associated with serious skin infection in any analysis. Among multiperson households with more than one person colonized, 50% carried the same strain. CONCLUSIONS/SIGNIFICANCE: The lack of association between S. aureus nasal colonization and serious skin infection underscores the need to explore alternative venues or body sites that may be crucial to transmission. Moreover, the magnitude of colonization and

eap Gene as novel target for specific identification of Staphylococcus aureus.

Science.gov (United States)

Hussain, Muzaffar; von Eiff, Christof; Sinha, Bhanu; Joost, Insa; Herrmann, Mathias; Peters, Georg; Becker, Karsten

2008-02-01

The cell surface-associated extracellular adherence protein (Eap) mediates adherence of Staphylococcus aureus to host extracellular matrix components and inhibits inflammation, wound healing, and angiogenesis. A well-characterized collection of S. aureus and non-S. aureus staphylococcal isolates (n = 813) was tested for the presence of the Eap-encoding gene (eap) by PCR to investigate the use of the eap gene as a specific diagnostic tool for identification of S. aureus. Whereas all 597 S. aureus isolates were eap positive, this gene was not detectable in 216 non-S. aureus staphylococcal isolates comprising 47 different species and subspecies of coagulase-negative staphylococci and non-S. aureus coagulase-positive or coagulase-variable staphylococci. Furthermore, non-S. aureus isolates did not express Eap homologs, as verified on the transcriptional and protein levels. Based on these data, the sensitivity and specificity of the newly developed PCR targeting the eap gene were both 100%. Thus, the unique occurrence of Eap in S. aureus offers a promising tool particularly suitable for molecular diagnostics of this pathogen.

Duplex Identification of Staphylococcus aureus by Aptamer and Gold Nanoparticles.

Science.gov (United States)

Chang, Tianjun; Wang, Libo; Zhao, Kexu; Ge, Yu; He, Meng; Li, Gang

2016-06-01

Staphylococcus aureus is the top common pathogen causing infections and food poisoning. Identification of S. aureus is crucial for the disease diagnosis and regulation of food hygiene. Herein, we report an aptamer-AuNPs based method for duplex identification of S. aureus. Using AuNPs as an indicator, SA23, an aptamer against S. aureus, can well identify its target from Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa. Furthermore, we find citrate-coated AuNPs can strongly bind to S. aureus, but not bind to Salmonella enterica and Proteus mirabilis, which leads to different color changes in salt solution. This colorimetric response is capable of distinguishing S. aureus from S. enteritidis and P. mirabilis. Thus, using the aptasensor and AuNPs together, S. aureus can be accurately identified from the common pathogens. This duplex identification system is a promising platform for simple visual identification of S. aureus. Additionally, in the aptasensing process, bacteria are incubated with aptamers and then be removed before the aptamers adding to AuNPs, which may avoid the interactions between bacteria and AuNPs. This strategy can be potentially applied in principle to detect other cells by AuNPs-based aptasensors.

Staphylococcus aureus biofilm removal by targeting biofilm-associated extracellular proteins

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Sudhir K Shukla

2017-01-01

Methods: Biofilm assay was done in 96-well microtitre plate to evaluate the effect of proteinase K on biofilms of bovine mastitis S. Aureus isolates. Extracellular polymeric substances were extracted and evaluated for their composition (protein, polysaccharides and extracellular DNA, before and after the proteinase K treatment. Results: Biofilm assay showed that 2 μg/ml proteinase K significantly inhibited biofilm development in bap-positive S. aureus V329 as well as other S. aureus isolates (SA7, SA10, SA33, SA352, but not in bap-mutant M556 and SA392 (a weak biofilm-producing strain. Proteinase K treatment on S. aureus planktonic cells showed that there was no inhibition of planktonic growth up to 32 μg/ml of proteinase K. Proteinase K treatment on 24 h old preformed biofilms showed an enhanced dispersion of bap-positive V329 and SA7, SA10, SA33 and SA352 biofilms; however, proteinase K did not affect the bap-mutant S. aureus M556 and SA392 biofilms. Biofilm compositions study before and after proteinase K treatment indicated that Bap might also be involved in eDNA retention in the biofilm matrix that aids in biofilm stability. When proteinase K was used in combination with antibiotics, a synergistic effect in antibiotic efficacy was observed against all biofilm-forming S. aureus isolates. Interpretation & conclusions: Proteinase K inhibited biofilms growth in S. aureus bovine mastitis isolates but did not affect their planktonic growth. An enhanced dispersion of preformed S. aureus biofilms was observed on proteinase K treatment. Proteinase K treatment with antibiotics showed a synergistic effect against S. aureus biofilms. The study suggests that dispersing S. aureus by protease can be of use while devising strategies againstS. aureus biofilms.

Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters

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Sinigalliano Christopher D

2011-01-01

Full Text Available Abstract Background Staphylococcus aureus including methicillin resistant S. aureus, MRSA, are human colonizing bacteria that commonly cause opportunistic infections primarily involving the skin in otherwise healthy individuals. These infections have been linked to close contact and sharing of common facilities such as locker rooms, schools and prisons Waterborne exposure and transmission routes have not been traditionally associated with S. aureus infections. Coastal marine waters and beaches used for recreation are potential locations for the combination of high numbers of people with close contact and therefore could contribute to the exposure to and infection by these organisms. The primary aim of this study was to evaluate the amount and characteristics of the shedding of methicillin sensitive S. aureus, MSSA and MRSA by human bathers in marine waters. Results Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA. Conclusions This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly

Characterization of methicillin-resistant Staphylococcus aureus Sequence Type 398

DEFF Research Database (Denmark)

Christiansen, Mette Theilgaard

Staphylococcus aureus is an opportunistic pathogen that colonizes the nares and skin surfaces of several animal species, including man. S. aureus can cause a wide variety of infections ranging from superficial soft tissue and skin infections to severe and deadly systemic infections. Traditionally S....... aureus and methicillin-resistant Staphylococcus aureus (MRSA) have been associated with hospitals, but during the past decades MRSA has emerged in the community and now a new branch of MRSA has been found in association with livestock (LA-MRSA). A specific lineage (multilocus sequence type 398 (ST398...

Research advance in rapid detection of foodborne Staphylococcus aureus

Directory of Open Access Journals (Sweden)

Xihong Zhao

2016-09-01

Full Text Available Staphylococcus aureus is a gram-positive, coccus-shaped facultative anaerobe and a member of the Staphylococcaceae family. In recent years, alimentary toxicosis caused by S. aureus is a very serious problem worldwide, which constitutes a great threat to public health. In this review, we tried to summarize the conventional methods and newly developed rapid detection techniques of S. aureus (traditional detection method, biochemical detection, immunology method, molecular biology, and biosensor method for their principles, advantages, disadvantages, and applications. Furthermore, the future perspectives of S. aureus detection methods were forecasted at last.

Population structure of Staphylococcus aureus in China

NARCIS (Netherlands)

Yan, Xiaomei

2015-01-01

The present PhD research was aimed at analysing the population structure of Staphylococcus aureus in China. Between 2000 and 2005 we found that patients from a single Chinese hospital showed increasing trends in antimicrobial resistance. Among methicillin-resistant S. aureus (MRSA), resistance

Prevalence of Methicillin-Resistant Staphylococcus aureus among ...

African Journals Online (AJOL)

Purpose: To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in apparently healthy ... treatment failures is vital. Keywords: Methicillin-resistant Staphylococcus aureus, Nasal swabs, Multidrug resistance, Rational .... defined as resistance to three or more classes of antibiotics other than the ...

Staphylococcus aureus and Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) in and Around Therapeutic Whirlpools in College Athletic Training Rooms

Science.gov (United States)

Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A.

2015-01-01

Context: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. Objective: To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Design: Cross-sectional study. Setting: National Collegiate Athletic Association Division I university. Patients or Other Participants: Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Main Outcome Measure(s): Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. Results: We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F2,238 = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Conclusions: Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses. PMID:25710853

In silico analysis for identifying potential vaccine candidates against Staphylococcus aureus

OpenAIRE

Delfani, Somayeh; Imani Fooladi, Abbas Ali; Mobarez, Ashraf Mohabati; Emaneini, Mohammad; Amani, Jafar; Sedighian, Hamid

2015-01-01

Purpose Staphylococcus aureus is one of the most important causes of nosocomial and community-acquired infections. The increasing incidence of multiple antibiotic-resistant S. aureus strains and the emergence of vancomycin resistant S. aureus strains have placed renewed interest on alternative means of prevention and control of infection. S. aureus produces a variety of virulence factors, so a multi-subunit vaccine will be more successful for preventing S. aureus infections than a mono-subuni...

Communications of Staphylococcus aureus and non-aureus Staphylococcus species from bovine intramammary infections and teat apex colonization.

Science.gov (United States)

Mahmmod, Yasser S; Klaas, Ilka Christine; Svennesen, Line; Pedersen, Karl; Ingmer, Hanne

2018-05-16

The role of non-aureus staphylococci (NAS) in the risk of acquisition of intramammary infections with Staphylococcus aureus is vague and still under debate. The objectives of this study were to (1) investigate the distribution patterns of NAS species from milk and teat skin in dairy herds with automatic milking systems, and (2) examine if the isolated NAS influences the expression of S. aureus virulence factors controlled by the accessory gene regulator (agr) quorum sensing system. In 8 herds, 14 to 20 cows with elevated somatic cell count were randomly selected for teat skin swabbing and aseptic quarter foremilk samples from right hind and left front quarters. Teat skin swabs were collected using the modified wet-dry method and milk samples were taken aseptically for bacterial culture. Colonies from quarters with suspicion of having NAS in milk or teat skin samples (or both) were subjected to MALDI-TOF assay for species identification. To investigate the interaction between S. aureus and NAS, 81 isolates NAS were subjected to a qualitative β-galactosidase reporter plate assay. In total, 373 NAS isolates were identified representing 105 from milk and 268 from teat skin of 284 quarters (= 142 cows). Sixteen different NAS species were identified, 15 species from teat skin and 10 species from milk. The most prevalent NAS species identified from milk were Staphylococcus epidermidis (50%), Staphylococcus haemolyticus (15%), and Staphylococcus chromogenes (11%), accounting for 76%. Meanwhile, the most prevalent NAS species from teat skin were Staphylococcus equorum (43%), S. haemolyticus (16%), and Staphylococcus cohnii (14%), accounting for 73%. Using reporter gene fusions monitoring transcriptional activity of key virulence factors and regulators, we found that out of 81 supernatants of NAS isolates, 77% reduced expression of hla, encoding a-hemolysin, 70% reduced expression of RNAIII, the key effector molecule of agr, and 61% reduced expression of spa encoding

Selective biosensing of Staphylococcus aureus using chitosan quantum dots

Science.gov (United States)

Abdelhamid, Hani Nasser; Wu, Hui-Fen

2018-01-01

Selective biosensing of Staphylococcus aureus (S. aureus) using chitosan modified quantum dots (CTS@CdS QDs) in the presence of hydrogen peroxide is reported. The method is based on the intrinsic positive catalase activity of S. aureus. CTS@CdS quantum dots provide high dispersion in aqueous media with high fluorescence emission. Staphylococcus aureus causes a selective quenching of the fluorescence emission of CTS@CdS QDs in the presence of H2O2 compared to other pathogens such as Escherichia coli and Pseudomonas aeruginosa. The intrinsic enzymatic character of S. aureus (catalase positive) offers selective and fast biosensing. The present method is highly selective for positive catalase species and requires no expensive reagents such as antibodies, aptamers or microbeads. It could be extended for other species that are positive catalase.

Discontinuation of antimicrobials and costs of treating patients with infection Descalonamento antimicrobiano y costos con el tratamiento de pacientes con infecciones Descalonamento de antimicrobiano e custos do tratamento de pacientes com infecção

Directory of Open Access Journals (Sweden)

Adriana Cristina de Oliveira

2012-01-01

Full Text Available OBJECTIVE: To evaluate the repercussions of discontinuation the cost with the antimicrobial treatment of patients with bloodstream infection. METHODS: A historical cohort study conducted in the intensive care unit of a hospital in Belo Horizonte (MG. The population included 62 patients with bloodstream infection caused by Staphylococcus aureus. Data were collected between March/2007 and March/2011 from patients' medical records, Commission of Hospital Infection Control and Sector of Costs, with descriptive and univariate analysis. RESULTS: Colonization was associated with the occurrence of infection with resistant microorganisms (p OBJETIVO: Evaluar las repercusiones del desescalamiento en los costos con el tratamiento antimicrobiano de pacientes con infección de la corriente sanguínea. MÉTODOS: Estudio de cohorte histórica realizado en una Unidad de Terapia Intensiva de un hospital de Belo Horizonte (MG. La población incluyó a 62 pacientes con infección de la corriente sanguínea causada por Staphylococcus aureus. Los datos fueron recolectados entre marzo/2007 y marzo/2011 en las historias clínicas de los pacientes, Comisión de Control de Infección Hospitalaria y Sector de Costos con análisis, descriptivo y univariado. RESULTADOS: La colonización estuvo asociada a la ocurrencia de infección por microorganismo resistente (pOBJETIVO: Avaliar as repercussões do descalonamento nos custos com o tratamento antimicrobiano de pacientes com infecção da corrente sanguínea. MÉTODOS: Estudo de coorte histórica realizado em Unidade de Terapia Intensiva de hospital de Belo Horizonte (MG. A população incluiu 62 pacientes com infecção da corrente sanguínea causada por Staphylococcus aureus. Os dados foram coletados entre março/2007 e março/2011 nos prontuários dos pacientes, Comissão de Controle de Infecção Hospitalar e Setor de Custos com análise, descritiva e univariada. RESULTADOS: A colonização esteve associada à ocorr

Dissemination of antibiotic resistance in methicillin-resistant Staphylococcus aureus and vancomycin-resistant S aureus strains isolated from hospital effluents.

Science.gov (United States)

Mandal, Santi M; Ghosh, Ananta K; Pati, Bikas R

2015-12-01

Vancomycin-resistant Staphylococcus aureus (VRSA) and methicillin-resistant S aureus (MRSA) strains were examined in hospital effluents. Most S aureus strains are resistant to methicillin (MRSA), followed by tetracycline. Approximately 15% of MRSA strains are also resistant to vancomycin (VRSA). All VRSA strains developed a VanR/VanS-regulated 2-component system of VanA-type resistance in their genome. Results indicate that there is a possibility of developing resistance to aminoglycosides by VRSA strains in the near future. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Methicillin-resistant Staphylococcus aureus in palliative care: A prospective study of Methicillin-resistant Staphylococcus aureus prevalence in a hospital-based palliative care unit.

Science.gov (United States)

Schmalz, Oliver; Strapatsas, Tobias; Alefelder, Christof; Grebe, Scott Oliver

2016-07-01

Methicillin-resistant Staphylococcus aureus is a common organism in hospitals worldwide and is associated with morbidity and mortality. However, little is known about the prevalence in palliative care patients. Furthermore, there is no standardized screening protocol or treatment for patients for whom therapy concentrates on symptom control. Examining the prevalence of methicillin-resistant Staphylococcus aureus in palliative care patients as well as the level of morbidity and mortality. We performed a prospective study where methicillin-resistant Staphylococcus aureus screening was undertaken in 296 consecutive patients within 48 h after admission to our palliative care unit. Medical history was taken, clinical examination was performed, and the Karnofsky Performance Scale and Palliative Prognostic Score were determined. Prevalence of Methicillin-resistant Staphylococcus aureus was compared to data of general hospital patients. In total, 281 patients were included in the study having a mean age of 69.7 years (standard deviation = 12.9 years) and an average Karnofsky Performance Scale between 30% and 40%. The mean length of stay was 9.7 days (standard deviation = 7.6 days). A total of 24 patients were methicillin-resistant Staphylococcus aureus positive on the first swab. Median number of swabs was 2. All patients with a negative methicillin-resistant Staphylococcus aureus swab upon admission remained Methicillin-resistant Staphylococcus aureus negative in all subsequent swabs. Our study suggests that the prevalence of Methicillin-resistant Staphylococcus aureus among patients in an in-hospital palliative care unit is much higher than in other patient populations. © The Author(s) 2016.

Bovine origin Staphylococcus aureus: A new zoonotic agent?

Science.gov (United States)

Rao, Relangi Tulasi; Jayakumar, Kannan; Kumar, Pavitra

2017-10-01

The study aimed to assess the nature of animal origin Staphylococcus aureus strains. The study has zoonotic importance and aimed to compare virulence between two different hosts, i.e., bovine and ovine origin. Conventional polymerase chain reaction-based methods used for the characterization of S. aureus strains and chick embryo model employed for the assessment of virulence capacity of strains. All statistical tests carried on R program, version 3.0.4. After initial screening and molecular characterization of the prevalence of S. aureus found to be 42.62% in bovine origin samples and 28.35% among ovine origin samples. Meanwhile, the methicillin-resistant S. aureus prevalence is found to be meager in both the hosts. Among the samples, only 6.8% isolates tested positive for methicillin resistance. The biofilm formation quantified and the variation compared among the host. A Welch two-sample t -test found to be statistically significant, t=2.3179, df=28.103, and p=0.02795. Chicken embryo model found effective to test the pathogenicity of the strains. The study helped to conclude healthy bovines can act as S. aureus reservoirs. Bovine origin S. aureus strains are more virulent than ovine origin strains. Bovine origin strains have high probability to become zoonotic pathogen. Further, gene knock out studies may be conducted to conclude zoonocity of the bovine origin strains.

Variation among Staphylococcus aureus membrane vesicle proteomes affects cytotoxicity of host cells.

Science.gov (United States)

Jeon, Hyejin; Oh, Man Hwan; Jun, So Hyun; Kim, Seung Il; Choi, Chi Won; Kwon, Hyo Il; Na, Seok Hyeon; Kim, Yoo Jeong; Nicholas, Asiimwe; Selasi, Gati Noble; Lee, Je Chul

2016-04-01

Staphylococcus aureus secretes membrane-derived vesicles (MVs), which can deliver virulence factors to host cells and induce cytopathology. However, the cytopathology of host cells induced by MVs derived from different S. aureus strains has not yet been characterized. In the present study, the cytotoxic activity of MVs from different S. aureus isolates on host cells was compared and the proteomes of S. aureus MVs were analyzed. The MVs purified from S. aureus M060 isolated from a patient with staphylococcal scalded skin syndrome showed higher cytotoxic activity toward host cells than that shown by MVs from three other clinical S. aureus isolates. S. aureus M060 MVs induced HEp-2 cell apoptosis in a dose-dependent manner, but the cytotoxic activity of MVs was completely abolished by treatment with proteinase K. In a proteomic analysis, the MVs from three S. aureus isolates not only carry 25 common proteins, but also carry ≥60 strain-specific proteins. All S. aureus MVs contained δ-hemolysin (Hld), γ-hemolysin, leukocidin D, and exfoliative toxin C, but exfoliative toxin A (ETA) was specifically identified in S. aureus M060 MVs. ETA was delivered to HEp-2 cells via S. aureus MVs. Both rETA and rHld induced cytotoxicity in HEp-2 cells. In conclusion, MVs from clinical S. aureus isolates differ with respect to cytotoxic activity in host cells, and these differences may result from differences in the MV proteomes. Further proteogenomic analysis or mutagenesis of specific genes is necessary to identify cytotoxic factors in S. aureus MVs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular typing of Staphylococcus aureus based on coagulase gene.

Science.gov (United States)

Javid, Faizan; Taku, Anil; Bhat, Mohd Altaf; Badroo, Gulzar Ahmad; Mudasir, Mir; Sofi, Tanveer Ahmad

2018-04-01

This study was conducted to study the coagulase gene-based genetic diversity of Staphylococcus aureus , isolated from different samples of cattle using restriction fragment length polymorphism (RFLP) and their sequence-based phylogenetic analysis. A total of 192 different samples from mastitic milk, nasal cavity, and pus from skin wounds of cattle from Military Dairy Farm, Jammu, India, were screened for the presence of S. aureus . The presumptive isolates were confirmed by nuc gene-based polymerase chain reaction (PCR). The confirmed S. aureus isolates were subjected to coagulase ( coa ) gene PCR. Different coa genotypes observed were subjected to RFLP using restriction enzymes Hae111 and Alu1 , to obtain the different restriction patterns. One isolate from each restriction pattern was sequenced. These sequences were aligned for maximum homology using the Bioedit softwareandsimilarity in the sequences was inferred with the help of sequence identity matrix. Of 192 different samples,39 (20.31%) isolates of S. aureus were confirmed by targeting nuc gene using PCR. Of 39 S. aureus isolates, 25 (64.10%) isolates carried coa gene. Four different genotypes of coa gene, i.e., 514 bp, 595 bp, 757 bp, and 802 bp were obtained. Two coa genotypes, 595 bp (15 isolates) and 802 bp (4 isolates), were observed in mastitic milk. 514 bp (2 isolates) and 757 bp (4 isolates) coa genotypes were observed from nasal cavity and pus from skin wounds, respectively. On RFLP using both restriction enzymes, four different restriction patterns P1, P2, P3, and P4 were observed. On sequencing, four different sequences having unique restriction patterns were obtained. The most identical sequences with the value of 0.810 were found between isolate S. aureus 514 (nasal cavity) and S. aureus 595 (mastitic milk), and thus, they are most closely related. While as the most distant sequences with the value of 0.483 were found between S. aureus 514 and S. aureus 802 isolates. The study, being localized

Manifestación clínica de la composición corporal en pacientes con síndrome de ovario poliquístico

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S.P. Arevalo Monter

2017-06-01

Full Text Available El síndrome de ovario poliquístico es un trastorno endocrino-metabólico que se explica como un hiperandrogenismo femenino funcional. Asociado a ello se desencadenan diversas alteraciones sistémicas, siendo la acumulación de tejido adiposo visceral una de las más importantes. Se ha demostrado que los andrógenos y el aumento de los ácidos grasos libres, como se ve en la obesidad de tipo central, inhiben la acción hepática de insulina que resulta en el hiperinsulinismo compensatorio secundario a la resistencia a la insulina, por lo tanto, las pacientes con síndrome de ovario poliquístico presentan diversas características clínicas, hormonales y metabólicas, dependiendo de su grasa corporal y del patrón de distribución, por lo que la clasificación en subgrupos nos puede ayudar a identificar los trastornos sistémicos que puede presentar cada paciente. Uno de estos parámetros es el fenotipo otorgado por la composición corporal, el cual puede determinarse a través de impedancia por fluido eléctrico, que permite conocer las proporciones de los distintos componentes del cuerpo humano. Por esta razón, debe considerarse actualmente, como parte del seguimiento de las pacientes con síndrome de ovario poliquístico, el estudio de la composición corporal para establecer la respuesta a los tratamientos empleados en la corrección de este trastorno sistémico.

A pig model of acute Staphylococcus aureus induced pyemia

DEFF Research Database (Denmark)

Nielsen, O. L.; Iburg, T.; Aalbæk, B.

2009-01-01

Background: Sepsis caused by Staphylococcus aureus constitutes an important cause of morbidity and mortality in humans, and the incidence of this disease-entity is increasing. In this paper we describe the initial microbial dynamics and lesions in pigs experimentally infected with S. aureus....... aureus isolated from man and an extension of the timeframe aiming at inducing sepsis, severe sepsis and septic shock....

Prevalence and resistance of commensal Staphylococcus aureus, including meticillin-resistant S aureus, in nine European countries: a cross-sectional study.

NARCIS (Netherlands)

Heijer, C.D.J. den; Bijnen, E.M.E. van; Paget, W.J.; Pringle, M.; Goossen, H.; Bruggeman, C.A.; Schellevis, F.G.; Stobberingh, E.E.

2013-01-01

Background: Information about the prevalence of Staphylococcus aureus resistance to antimicrobial drugs has mainly been obtained from invasive strains, although the commensal microbiota is thought to be an important reservoir of resistance. We aimed to compare the prevalence of nasal S aureus

Protective effects of tenuigenin on Staphylococcus aureus-induced pneumonia in mice.

Science.gov (United States)

Yu, Bin; Qiao, Jiutao; Shen, Yongbin; Li, Lianyong

2017-09-01

Pneumonia is the leading cause of death in infants and young children. Staphylococcus aureus (S.aureus) is one of the most important bacteria that leads to pneumonia. Tenuigenin (TGN), a major active component isolated from the root of the Chinese herb Polygala tenuifolia, has been known to have anti-inflammatory effect. In this study, we aimed to investigate the protective effects of TGN on S.aureus-induced pneumonia in mice. The results showed that TGN significantly attenuated S.aureus-induced lung histopathological changes. TGN also inhibited lung wet/dry (W/D) ratio, and inflammatory cytokines TNF-α and IL-1β production. Furthermore, S.aureus-induced NF-κB activation was significantly inhibited by the treatment of TGN. In conclusion, the results of this study showed that TGN protected against S.aureus-induced pneumonia by inhibiting NF-κB activation. TGN might be a potential agent in the treatment of pneumonia induced by S.aureus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Survey and properties of Staphylococcus aureus isolated from Japanese-style desserts.

Science.gov (United States)

Shimamura, Yuko; Kidokoro, Shiho; Murata, Masatsune

2006-07-01

We surveyed the contamination of 315 Japanese- and western-style desserts and 247 human hands by Staphylococcus aureus and other staphylococcal bacteria. The most frequently isolated staphylococcal bacterium was S. warneri, followed by S. aureus. Only 1.9% of western-style desserts were contaminated by S. aureus strains, while 19.4% and 13.0% of Japanese-style desserts and human hands respectively were contaminated. Ninety-four isolates of S. aureus were characterized as to their biological properties and enterotoxigenicity. Although staphylococcal enterotoxins (SEs) were detected by enzyme-linked immunosorbent assay in the cultured broth of all S. aureus isolates, the reversed passive latex agglutination method and the polymerase chain reaction showed only 39 (41.5%) and 40 (42.6%) samples respectively as SE-positive. The predominant type of SE was SEB (67.5%), and eight strains produced SEA. None of the S. aureus strains had penicillin-binding protein 2', showing that methicillin-resistant S. aureus was not present in the samples.

Root cause analysis of methicillin resistant Staphylococcus aureus bacteraemia.

Science.gov (United States)

Aslam, Nadia; Mehdi, Naima; Izhar, Mateen

2015-10-01

To find the important risk factors and sources of bacteraemia in patients suffering from methicillin-resistant staphylococcus aureus bacteraemia. The descriptive study was carried out at Shaikh Zayed Hospital, Lahore, from October 2010 to August 2011. Blood cultures were processed to isolate methicillin-resistant staphylococcus aureus. A questionnaire was completed by the participating patients suffering from bacteraemia. Information about risk factors present at the time and risk factors that served as the source of bacteraemia were noted. Total 4058 blood cultures were processed and 669(16.5%) were positive. Of them, 194(29%) cultures were found to be positive for staphylococci. Out of these 194 blood cultures, coagulase-negative staphylococci were isolated from 117(60%), and 77(40%) were positive for S. aureus. Out of these 77 samples, 26(34%) were found to be methicillin-sensitive staphylococcus aureus and 51(66%) were methicillin-resistant staphylococcus aureus. The overall frequency of methicillin-resistant staphylococcus aureus was 1.25%; 7.62% out of positive blood culture; 26.28% out of total staphylococci; and 66% out of total S. aureus. As for the source of infection, central venous pressure line 11(21.6%), post-influenza pneumonia 9(17.6%), peripheral intravenous line 8(15.7%) and dialysis line 7(13.7%) were major reasons. Taking care of aseptic measures while insertion, frequent change and early removal of the central venous and dialysis lines is of critical significance.

Targeting Staphylococcus aureus Toxins: A Potential form of Anti-Virulence Therapy

Directory of Open Access Journals (Sweden)

Cin Kong

2016-03-01

Full Text Available Staphylococcus aureus is an opportunistic pathogen and the leading cause of a wide range of severe clinical infections. The range of diseases reflects the diversity of virulence factors produced by this pathogen. To establish an infection in the host, S. aureus expresses an inclusive set of virulence factors such as toxins, enzymes, adhesins, and other surface proteins that allow the pathogen to survive under extreme conditions and are essential for the bacteria’s ability to spread through tissues. Expression and secretion of this array of toxins and enzymes are tightly controlled by a number of regulatory systems. S. aureus is also notorious for its ability to resist the arsenal of currently available antibiotics and dissemination of various multidrug-resistant S. aureus clones limits therapeutic options for a S. aureus infection. Recently, the development of anti-virulence therapeutics that neutralize S. aureus toxins or block the pathways that regulate toxin production has shown potential in thwarting the bacteria’s acquisition of antibiotic resistance. In this review, we provide insights into the regulation of S. aureus toxin production and potential anti-virulence strategies that target S. aureus toxins.

Photoreactivation of ultraviolet-irradiation damage in Staphylococcus aureus

International Nuclear Information System (INIS)

Adkins, B. Jr.; Allen, W.E.

1982-01-01

This study reports the capacity of Staphylococcus aureus strain 7 - 8 to undergo photoenzymatic repair of UV-irradiation induced damage and compares it to the photoreactivation (PR) response of Escherichia coli strain B. Staphylococcus aureaus showed greater inhibition by UV irradiation than E. coli, consistent with its higher adenine and thymine content of DNA. Staphylococcus aureus showed an enhanced rate of photoreactivation with no lag in initiation of the PR response at low PR doses compared to E. coli. Maximum PR capacity of both cultures was about equal and occurred in cultures incubated at 23 - 25 0 . The PR responses at 11 - 12 and 35 - 37 0 for S. aureus and E. coli differed although both were capable of PR at each of these temperatures. The PR response of E. coli was directly related to the dosage of PR light (J/m 2 ); however, the photoenzymatic capacity of S. aureus was not directly responsive to continued decrease in light intensity. The capacity of S. aureus to undergo liquid holding recovery (LHR) occurred at 23 - 25 0 (not at 11 - 12 0 or 35 - 37 0 ), whereas E. coli underwent LHR at 11 - 12 0 and 23 - 25 0 but not at 35 - 37 0 . The LHR response of S. aureus was somewhat more effective than E. coli and did not show the direct response to increased liquid-holding period as did E. coli. (author)

Antibiotic resistance of Staphylococcus aureus isolated from fresh ...

African Journals Online (AJOL)

Antibiotic resistance of Staphylococcus aureus isolated from fresh cow milk in settled ... produced alpha haemolysin, 45.5% (n=25) produced beta haemolysin and ... resistant strains of S. aureus of animal and human biotypes and can serve as ...

Simple method for correct enumeration of Staphylococcus aureus

DEFF Research Database (Denmark)

Haaber, J.; Cohn, M. T.; Petersen, A.

2016-01-01

culture. When grown in such liquid cultures, the human pathogen Staphylococcus aureus is characterized by its aggregation of single cells into clusters of variable size. Here, we show that aggregation during growth in the laboratory standard medium tryptic soy broth (TSB) is common among clinical...... and laboratory S. aureus isolates and that aggregation may introduce significant bias when applying standard enumeration methods on S. aureus growing in laboratory batch cultures. We provide a simple and efficient sonication procedure, which can be applied prior to optical density measurements to give...

Research advance in rapid detection of foodborne Staphylococcus aureus

OpenAIRE

Xihong Zhao; Caijiao Wei; Junliang Zhong; Shiwei Jin

2016-01-01

Staphylococcus aureus is a gram-positive, coccus-shaped facultative anaerobe and a member of the Staphylococcaceae family. In recent years, alimentary toxicosis caused by S. aureus is a very serious problem worldwide, which constitutes a great threat to public health. In this review, we tried to summarize the conventional methods and newly developed rapid detection techniques of S. aureus (traditional detection method, biochemical detection, immunology method, molecular biology, and biosensor...

Active immunization with an octa-valent Staphylococcus aureus antigen mixture in models of S. aureus bacteremia and skin infection in mice.

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Sanne van den Berg

Full Text Available Proteomic studies with different Staphylococcus aureus isolates have shown that the cell surface-exposed and secreted proteins IsaA, LytM, Nuc, the propeptide of Atl (pro-Atl and four phenol-soluble modulins α (PSMα are invariantly produced by this pathogen. Therefore the present study was aimed at investigating whether these proteins can be used for active immunization against S. aureus infection in mouse models of bacteremia and skin infection. To this end, recombinant His-tagged fusions of IsaA, LytM, Nuc and pro-Atl were isolated from Lactococcus lactis or Escherichia coli, while the PSMα1-4 peptides were chemically synthesized. Importantly, patients colonized by S. aureus showed significant immunoglobulin G (IgG responses against all eight antigens. BALB/cBYJ mice were immunized subcutaneously with a mixture of the antigens at day one (5 μg each, and boosted twice (25 μg of each antigen with 28 days interval. This resulted in high IgG responses against all antigens although the response against pro-Atl was around one log lower compared to the other antigens. Compared to placebo-immunized mice, immunization with the octa-valent antigen mixture did not reduce the S. aureus isolate P load in blood, lungs, spleen, liver, and kidneys in a bacteremia model in which the animals were challenged for 14 days with a primary load of 3 × 10(5 CFU. Discomfort scores and animal survival rates over 14 days did not differ between immunized mice and placebo-immunized mice upon bacteremia with S. aureus USA300 (6 × 10(5 CFU. In addition, this immunization did not reduce the S. aureus isolate P load in mice with skin infection. These results show that the target antigens are immunogenic in both humans and mice, but in the used animal models do not result in protection against S. aureus infection.

Assessing the potential for raw meat to influence human colonization with Staphylococcus aureus

OpenAIRE

Carrel, Margaret; Zhao, Chang; Thapaliya, Dipendra; Bitterman, Patrick; Kates, Ashley E.; Hanson, Blake M.; Smith, Tara C.

2017-01-01

The role of household meat handling and consumption in the transfer of Staphylococcus aureus (S. aureus) from livestock to consumers is not well understood. Examining the similarity of S. aureus colonizing humans and S. aureus in meat from the stores in which those individuals shop can provide insight into the role of meat in human S. aureus colonization. S. aureus isolates were collected from individuals in rural and urban communities in Iowa (n?=?3347) and contemporaneously from meat produc...

Caracterización de tilapia roja (Oreochromis sp. con marcadores moleculares RAPD

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Julieta Torres Jaramillo

2010-04-01

Full Text Available Se utilizó la técnica RAPD (amplificación al azar de ADN polimórfico para el estudio de la diversidad genética de Oreochromis sp. (tilapia roja en cinco piscícolas del Valle del Cauca (Colombia y en la determinación del nivel de introgresión de las especies parentales Oreochromis mosambicus, O. niloticus y O. aureus. Se evaluaron 25 cebadores, ocho fueron polimórficos y se obtuvieron 109 bandas. Los valores de heterocigosidad esperada (0.196 a 0.256 y la estructura genética (Gst = 0.22 para Oreochromis sp. indicaron un elevado grado de polimorfismo y alta estructuración genética. Estos resultados fueron consistente con el Fst = 0.268 (P < 0.0001 dado por el Amova y el Gst = 0.040 del análisis de correspondencia múltiple. Los valores de similitud genética, el análisis de grupo, el análisis de correspondencia múltiple y el nivel de introgresion, indicaron diferencias significativas (P<0.0001 en los niveles de introgresión. El bajo nivel de diferenciación genética entre poblaciones podría ser el resultado de peces con el mismo origen genético y la alta variación dentro de poblaciones se puede presentar por prácticas de manejo. La introgresión entre piscícolas es significativa para O. aureus, mientras que las especies O. niloticus y O. mosambicus se encuentran introgresadas de forma similar en las poblaciones de Oreochromis sp.

Intercenter reproducibility of binary typing for Staphylococcus aureus

NARCIS (Netherlands)

van Leeuwen, Willem B.; Snoeijers, Sandor; van der Werken-Libregts, Christel; Tuip, Anita; van der Zee, Anneke; Egberink, Diane; de Proost, Monique; Bik, Elisabeth; Lunter, Bjorn; Kluytmans, Jan; Gits, Etty; van Duyn, Inge; Heck, Max; van der Zwaluw, Kim; Wannet, Wim; Noordhoek, Gerda T.; Mulder, Sije; Renders, Nicole; Boers, Miranda; Zaat, Sebastiaan; van der Riet, Daniëlle; Kooistra, Mirjam; Talens, Adriaan; Dijkshoorn, Lenie; van der Reyden, Tanny; Veenendaal, Dick; Bakker, Nancy; Cookson, Barry; Lynch, Alisson; Witte, Wolfgang; Cuny, Christa; Blanc, Dominique; Vernez, Isabelle; Hryniewicz, Waleria; Fiett, Janusz; Struelens, Marc; Deplano, Ariane; Landegent, Jim; Verbrugh, Henri A.; van Belkum, Alex

2002-01-01

The reproducibility of the binary typing (BT) protocol developed for epidemiological typing of Staphylococcus aureus was analyzed in a biphasic multicenter study. In a Dutch multicenter pilot study, 10 genetically unique isolates of methicillin-resistant S. aureus (MRSA) were characterized by the BT

The changing epidemiology of Staphylococcus aureus bloodstream infection

DEFF Research Database (Denmark)

Laupland, K.B.; Lyytikäinen, O.; Søgaard, Mette

2013-01-01

Clin Microbiol Infect ABSTRACT: Although the epidemiology of Staphylococcus aureus bloodstream infection (BSI) has been changing, international comparisons are lacking. We sought to determine the incidence of S. aureus BSI and assess trends over time and by region. Population-based surveillance w...

Staphylococcus aureus small colony variants in diabetic foot infections

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Estrella Cervantes-García

2015-03-01

Full Text Available Background: Staphylococcus aureus (S. aureus is one of the major pathogens causing chronic infections. The ability of S. aureus to acquire resistance to a diverse range of antimicrobial compounds results in limited treatment options, particularly in methicillin-resistant S. aureus (MRSA. A mechanism by which S. aureus develops reduced susceptibility to antimicrobials is through the formation of small colony variants (SCVs. Infections by SCVs of S. aureus are an upcoming problem due to difficulties in laboratory diagnosis and resistance to antimicrobial therapy. Methods: A prospective study was performed on 120 patients diagnosed with both type 2 diabetes mellitus and infected diabetic foot ulcers. The study was carried out from July 2012 to December 2013 in Hospital General de Mexico. The samples were cultured in blood agar, mannitol salt agar, and MacConkey agar media, and incubated at 37°C in aerobic conditions. Results: We describe the first known cases of diabetic foot infections caused by MRSA-SCVs in patients diagnosed with type 2 diabetes mellitus and infected diabetic foot ulcers. In all of our cases, the patients had not received any form of gentamicin therapy. Conclusions: The antibiotic therapy commonly used in diabetic patients with infected diabetic foot ulcers fails in the case of MRSA-SCVs because the intracellular location protects S. aureus-SCVs from the host's defenses and also helps them resist antibiotics. The cases studied in this article add to the spectrum of persistent and relapsing infections attributed to MRSA-SCVs and emphasizes that these variants may also play a relevant role in diabetic foot infections.

A meta-analysis of the rates of Staphylococcus aureus and methicillin-resistant S aureus contamination on the surfaces of environmental objects that health care workers frequently touch.

Science.gov (United States)

Lin, Dongxin; Ou, Qianting; Lin, Jialing; Peng, Yang; Yao, Zhenjiang

2017-04-01

Health care workers may potentially spread Staphylococcus aureus and methicillin-resistant S aureus (MRSA) to patients by contaminated high-touch items. We aimed to determine the pooled rates of S aureus and MRSA contamination and influencing factors. A literature search of the PubMed, ScienceDirect, Embase, Ovid, and Scopus databases was performed. Pooled contamination rates were determined using random effect models. Subgroup and meta-regression analyses were conducted to identify factors potentially influencing the rates of S aureus and MRSA contamination. Sensitivity and publication bias analyses were performed. Thirty-eight studies were included in the meta-analysis. The pooled contamination rates were 15.0% (95% confidence interval [CI], 9.8%-21.1%) for S aureus and 5.0% (95% CI, 2.7%-7.7%) for MRSA. The subgroup analyses indicated that the pooled rate of S aureus contamination was significantly higher for studies conducted in South America, in developing countries, and during 2010-2015. The pooled rate of MRSA contamination was significantly higher for studies conducted in Africa. The meta-regression analysis suggested that the pooled rate of S aureus contamination was lower for studies conducted in developed countries (odds ratio, 0.664; 95% CI, 0.509-0.867; P = .004). No bias was found in the publication of the rates of S aureus and MRSA contamination. S aureus and MRSA contamination statuses of high-touch items are worrisome and should be paid greater attention. Developing country status was a risk factor for S aureus contamination. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Nasal carriage of methicilli-resistant staphylococcus aureus with ...

African Journals Online (AJOL)

Staphylococcus aureus isolates were collected from anterior nares of fifty healthy adults in Zaria and their antibiotic susceptibility patterns determined. Seventy-two percent (72%) of the isolates were methicillin-resistant S. aureus, while 20% were methicillin-susceptible. The isolates were generally resistant to multiple ...

Breast Milk Is a Potential Reservoir for Livestock-Associated Staphylococcus aureus and Community-Associated Staphylococcus aureus in Shanghai, China

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Xiaoliang Li

2018-01-01

Full Text Available Breast milk is the first choice in feeding newborn infants and provides multiple benefits for their growth and development. Staphylococcus aureus usually exists in breast milk and is considered one of the most important causative infective agents. To be effective in preventing and controlling S. aureus infections among infants, the aim of this study was to determine the occurrence and molecular characteristics of S. aureus isolated from 1102 samples of breast milk between 2015 and 2016 in Shanghai, China. Out of 71 S. aureus strains isolated, 15 (21.1%, 15/71 were MRSA and all the strains were characterized by spa typing, Multi-Locus Sequence Typing, SCCmec typing, antibiotic resistance testing and virulence-associated genes. A total of 18 distinct sequence types (STs and 36 spa types were identified within the 71 isolates, among which the most frequently represented was ST398 (19.7%, 14/71, followed by ST7 (18.3%, 13/71, ST59 (16.9%, 12/71. The three predominant STs accounted for more than one half of all S. aureus isolates. The most prevalent spa types were t091 (12.7%, 9/71, followed by t571 (8.5%, 6/71, t189 (7.0%, 5/71, t034 (5.6%, 4/71, t437 (5.6%, 4/71, and t701 (4.2%, 3/71. All MRSA isolates belonged to SCCmec IV and V, accounting for 66.7 and 33.3% respectively. Notably, 23 (32.4% S. aureus strains were multidrug resistance (MDR, including 4 (5.6% MRSA and 19 (26.8% MSSA strains, and MDR isolates were mostly resistant to penicillin, erythromycin and clindamycin. All isolates exhibited simultaneous carriage of at least 5 of 33 possible virulence genes and the most prevalent genes detected were icaA (100%, clfA (100%, hla (100%, sdrC (94.4%, hlg2 (88.7%, lukE (57.8%. 39 (54.9%, 39/71 isolates, including 9 (12.7% of MRSA isolates, harbored ≥10 tested virulence genes evaluated in this study. The pvl gene was detected in 8 strains, which represented 5 different STs, with ST59 being the most one. Overall, our findings showed that S. aureus

Fotoperiodo y Ontogenia Inicial de Peces Migratorios en Brasil con Énfasis en Sábalo (Prochilodus lineatus)

OpenAIRE

Hernández Cuadrado, Ever Edrey; Solis Murgas, Luis David; Buitrago Cardozo, Michael de Jesús

2016-01-01

El estudio de los aspectos reproductivos y de la ontogenia de los peces migradores es de gran importancia en piscicultura, especialmente cuando se trata de especies nativas, resaltándose los patrones de crecimiento y desarrollo. El objetivo del presente trabajo fue hacer una compilación del conocimiento actual de la ontogenia de sábalo, Prochilodus lineatus, en las fases de embrión y larva, bajo ambientes fóticos variables y desde la perspectiva de la capacidad adaptativa del fenotipo. Además...

Environmental contamination with Staphylococcus aureus at a large, Midwestern university campus.

Science.gov (United States)

Thapaliya, Dipendra; Taha, Mohammed; Dalman, Mark R; Kadariya, Jhalka; Smith, Tara C

2017-12-01

Staphylococcus aureus can cause minor to severe life-threatening infections. The changing epidemiology of S. aureus is of public health concern due to the emergence of multi-drug resistant (MDR) strains. Environmental surfaces play a crucial role in the transmission of S. aureus. The objective of this study was to examine environmental contamination and molecular characteristics of S. aureus in health professional-associated (HPA) and non-health professional-associated (NHPA) buildings at a large university. A total of 152 environmental surface samples were collected from two HPA and two NHPA campus buildings. Bacterial culture and diagnostics were done using standard microbiology methods. Polymerase chain reaction was conducted to detect mecA and PVL genes. All isolates were spa typed. A subset of isolates was characterized via multi-locus sequence typing (MLST). All S. aureus isolates were tested for antibiotic susceptibility. The overall contamination of S. aureus and methicillin-resistant S. aureus (MRSA) was 22.4% (34/152) and 5.9% (9/152) respectively. Similar prevalence of contamination was found in HPA and NHPA buildings. A total of 17 different spa types were detected among 34 S. aureus isolates. The majority of the MRSA isolates belonged to clonal complex (CC) 8. One isolate was positive for PVL. Eleven different sequence types (STs) were detected from 17 tested isolates. ST8 was the most common. Twelve isolates (35.3%) were MDR. Almost 27% (9/34) of the isolates were MRSA. The highest contamination of S. aureus was found in high hand-touch areas such as door knobs, suggesting that human interaction in crowded environments such as academic institutions plays a crucial role in S. aureus/MRSA transmission via inanimate objects. Additionally, more than one-third of the isolates were MDR. These data reinforce the need to implement effective prevention strategies outside the healthcare setting to decrease the incidence of drug-resistant S. aureus infections

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus

OpenAIRE

Jing Zhang; Yujuan Suo; Daofeng Zhang; Fangning Jin; Hang Zhao; Chunlei Shi

2018-01-01

Staphyloxanthin (STX), a golden carotenoid pigment produced by Staphylococcus aureus, is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to...

Epithelial Cell Gene Expression Induced by Intracellular Staphylococcus aureus

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Xianglu Li

2009-01-01

Full Text Available HEp-2 cell monolayers were cocultured with intracellular Staphylococcus aureus, and changes in gene expression were profiled using DNA microarrays. Intracellular S. aureus affected genes involved in cellular stress responses, signal transduction, inflammation, apoptosis, fibrosis, and cholesterol biosynthesis. Transcription of stress response and signal transduction-related genes including atf3, sgk, map2k1, map2k3, arhb, and arhe was increased. In addition, elevated transcription of proinflammatory genes was observed for tnfa, il1b, il6, il8, cxcl1, ccl20, cox2, and pai1. Genes involved in proapoptosis and fibrosis were also affected at transcriptional level by intracellular S. aureus. Notably, intracellular S. aureus induced strong transcriptional down-regulation of several cholesterol biosynthesis genes. These results suggest that epithelial cells respond to intracellular S. aureus by inducing genes affecting immunity and in repairing damage caused by the organism, and are consistent with the possibility that the organism exploits an intracellular environment to subvert host immunity and promote colonization.

Staphylococcus aureus bacteraemia in children: a formidable foe ...

African Journals Online (AJOL)

Staphylococcus aureus remains one of the most common causes of bacteraemia in children. In order to evade and overcome the immune responses of its host and any antimicrobial therapies aimed at destroying it, this organism, through various mechanisms, continues to evolve. Staphylococcus aureus bacteraemia is a ...

Antibiotic sensitivity pattern of Staphylococcus aureus from clinical

African Journals Online (AJOL)

raoul

2011-01-26

Jan 26, 2011 ... Key words: Staphylococcus aureus, antibiotic sensitivity, Nigeria, Kano ... infection have an increased colonization risks [8]. ... confirmed Staphylococcus aureus isolates was prepared in peptone water to ... 5 g methicillin discs (oxoid, USA) were aseptically placed on the surface of the inoculated plates and ...

Detection of some virulence factors in Staphylococcus aureus ...

African Journals Online (AJOL)

USER

2010-06-21

Jun 21, 2010 ... Mastitis is one of the common diseases of dairy cattle and an inflammatory ... Key words: Bovine mastitis, Staphylococcus aureus, virulence factors, ... frequent cause of subclinical intramammary infections in ... genotypes has not been investigated. ... genes in S. aureus, we were particularly interested in the.

Mechanisms of antibiotic resistance in Staphylococcus aureus.

Science.gov (United States)

Pantosti, Annalisa; Sanchini, Andrea; Monaco, Monica

2007-06-01

Staphylococcus aureus can exemplify better than any other human pathogen the adaptive evolution of bacteria in the antibiotic era, as it has demonstrated a unique ability to quickly respond to each new antibiotic with the development of a resistance mechanism, starting with penicillin and methicillin, until the most recent, linezolid and daptomycin. Resistance mechanisms include enzymatic inactivation of the antibiotic (penicillinase and aminoglycoside-modification enzymes), alteration of the target with decreased affinity for the antibiotic (notable examples being penicillin-binding protein 2a of methicillin-resistant S. aureus and D-Ala-D-Lac of peptidoglycan precursors of vancomycin-resistant strains), trapping of the antibiotic (for vancomycin and possibly daptomycin) and efflux pumps (fluoroquinolones and tetracycline). Complex genetic arrays (staphylococcal chromosomal cassette mec elements or the vanA operon) have been acquired by S. aureus through horizontal gene transfer, while resistance to other antibiotics, including some of the most recent ones (e.g., fluoroquinolones, linezolid and daptomycin) have developed through spontaneous mutations and positive selection. Detection of the resistance mechanisms and their genetic basis is an important support to antibiotic susceptibility surveillance in S. aureus.

Bases moleculares de alfa-talasemia en la Argentina

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Karen G Scheps

2015-04-01

Full Text Available La α-talasemia, es uno de los desórdenes hereditarios más frecuentes mundialmente. Al presente, el diagnóstico molecular es la única herramienta que permite el diagnóstico certero. El propósito de este trabajo fue caracterizar las bases moleculares de estos síndromes en nuestro medio, y establecer relaciones genotipo-fenotipo. Mediante la complementación de distintas técnicas de biología molecular e hibridación fluorescente in situ (FISH, se logró poner en evidencia la presencia de mutaciones α-talasémicas en 145 de 184 (78.8% pacientes estudiados con perfil hematológico compatible con α-talasemia. Dentro de este grupo, las deleciones correspondieron al defecto genético más frecuente, prevaleciendo la mutación -α3.7 en genotipos heterocigotas y homocigotas. Asimismo, en pacientes con fenotipo α0 las deleciones prevalentes fueron -MED y -CAL/CAMP. Este estudio permitió también describir una deleción de la región sub-telomérica en un paciente con α-talasemia y retraso mental. En el 7.6% de los pacientes caracterizados clínicamente como posibles α-talasémicos (microcitosis con valores de Hb A2 inferiores al 3.5%, se hallaron mutaciones β-talasémicas en estado heterocigota. Se lograron establecer perfiles hematológicos asociados a los genotipos α+ y α0 para pacientes adultos y niños. Esperamos que este trabajo pueda servir como guía para reconocer posibles portadores α-talasémicos. También permite destacar el trabajo en conjunto de médicos hematólogos, el laboratorio (bioquímico y de biología molecular y de los médicos genetistas, con el fin de proporcionar adecuado consejo genético.

Staphylococcus aureus CC398

DEFF Research Database (Denmark)

Price, Lance B.; Stegger, Marc; Hasman, Henrik

2012-01-01

Since its discovery in the early 2000s, methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 398 (CC398) has become a rapidly emerging cause of human infections, most often associated with livestock exposure. We applied whole-genome sequence typing to characterize a diverse collection...... of CC398 isolates (n = 89), including MRSA and methicillin-susceptible S. aureus (MSSA) from animals and humans spanning 19 countries and four continents. We identified 4,238 single nucleotide polymorphisms (SNPs) among the 89 core genomes. Minimal homoplasy (consistency index = 0.9591) was detected...... among parsimony-informative SNPs, allowing for the generation of a highly accurate phylogenetic reconstruction of the CC398 clonal lineage. Phylogenetic analyses revealed that MSSA from humans formed the most ancestral clades. The most derived lineages were composed predominantly of livestock...

Population structure analyses of Staphylococcus aureus at Tygerberg Hospital, South Africa, reveals a diverse population, a high prevalence of Panton-Valentine leukocidin genes, and unique local methicillin-resistant S. aureus clones

NARCIS (Netherlands)

Oosthuysen, W. F.; Orth, H.; Lombard, C. J.; Sinha, B.; Wasserman, E.

Studies reporting on the population structure of Staphylococcus aureus in South Africa have focused only on methicillin-resistant S. aureus (MRSA). This study describes the population structure of S. aureus, including methicillin-susceptible S. aureus (MSSA) isolated from patients at Tygerberg

Invasive Staphylococcus aureus infection in an African adolescent ...

African Journals Online (AJOL)

Staphylococcus aureus remains an important cause of mortality, in the community and health care set-ups. S. aureus strains with genes encoding lethal toxins and culture negative sepsis augment the diagnostic challenge in resource limited settings. With a growing rate of resistance to the causative bacteria and atypical ...

Prevalence and risk factors for Staphylococcus aureus and ...

African Journals Online (AJOL)

Prevalence and risk factors for Staphylococcus aureus and methicillin‑resistant Staphylococcus aureus nasal carriage inpatients in a tertiary care hospital's chest clinic in Turkey. ... of the participants and risk factors for carriage. Fisher's exact test, univariate and multivariate logistic regression analysis were used. A P < 0.05 ...

Dehydrosqualene Desaturase as a Novel Target for Anti-Virulence Therapy against Staphylococcus aureus

OpenAIRE

Gao, Peng; Davies, Julian; Kao, Richard Yi Tsun

2017-01-01

ABSTRACT Staphylococcus aureus, especially methicillin-resistant S.?aureus (MRSA), is a life-threatening pathogen in hospital- and community-acquired infections. The golden-colored carotenoid pigment of S.?aureus, staphyloxanthin, contributes to the resistance to reactive oxygen species (ROS) and host neutrophil-based killing. Here, we describe a novel inhibitor (NP16) of S.?aureus pigment production that reduces the survival of S.?aureus under oxidative stress conditions. Carotenoid componen...

Evaluación de cuatro métodos para la detección de Staphylococcus aureus meticilino-resistente de muestras clínicas en un hospital regional Evaluation of four methods for detecting methicillin-resistant Staphylococcus aureus isolates from clinical specimens at a regional hospital in Mexico

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Gabriel Acosta-Pérez

2012-02-01

Full Text Available OBJETIVO: Investigar la prevalencia de Staphylococcus aureus meticilino-resistente (MRSA en aislados clínicos y determinar la concordancia entre los métodos de detección de MRSA en un laboratorio con recursos y personal limitado. MATERIAL Y MÉTODOS: Se analizaron 140 cepas de Staphylococcus aureus aisladas de muestras clínicas de diferentes departamentos mediante pruebas convencionales: producción de β-lactamasa, sensibilidad a oxacilina con MIC-Vitek 2-XL, ChromID MRSA, difusión en agar para discos de 30 μg de cefoxitina, detección de PBP2a y PCR para el gen mecA. Se determinó el índice kappa de Cohen, para evaluar la concordancia entre los diferentes métodos utilizados. RESULTADOS: La prevalencia encontrada fue de 90.7%. La sensibilidad y especificidad para los diferentes métodos de detección fue: difusión en disco para cefoxitina 97 y 92% respectivamente, MIC Vitek 2-XL 97 y 69%, ChromoID MRSA 97 y 85% y detección de PBP2a 98 y 100%. CONCLUSIONES: Todos los métodos son muy buenos para la detección de MRSA; la elección en el uso de cada método dependerá de la infraestructura de cada laboratorio.OBJETIVE: To estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA in clinical isolates and to compare different methods for detection of MRSA in a lab with limited available personnel and resources. MATERIAL AND METHODS: 140 Staphylococcus aureus strains isolated from patients in several departments were assayed for β-lactamase production, MIC-Vitek 2 oxacillin, ChromID MRSA, disk diffusion in agar for cefoxitin 30 μg and PBP2a detection. The results of conventional tests were compared with the "gold standard" PCR test for mecA gene. Cohen´s kappa index was also calculated in order to evaluate the intra assay agreement between the used methods. RESULTS: The found prevalence was 90.7%. Sensitivity and specificity were: disk diffusion for cefoxitin 97 and 92% respectively, MIC Vitek 2-XL 97 and 69%, Chromo

Portación y caracterización de Staphylococcus aureus en manipuladores de alimentos Carriage and characterization of Staphylococcus aureus in food handlers

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Graciela B Jordá

2012-06-01

Full Text Available Staphylococcus aureus es una causa de intoxicaciones alimentarias por su capacidad de producir enterotoxinas. Los manipuladores de alimentos que portan S. aureus productores de enterotoxinas pueden provocar intoxicaciones alimentarias. Se estudiaron muestras tomadas de fosas nasales de 88 manipuladores de alimentos en la provincia de Misiones. El 37,5 % de los individuos analizados eran portadores de S. aureus. Mediante técnicas de amplificación (PCR, se detectaron genes que codifican la producción de enterotoxinas en 13 de los 33 aislamientos obtenidos (39,4 % y en el 14,7 % de los manipuladores. De estos aislamientos, 10 portaban el gen sea y 3 el gen sec. El estudio de sensibilidad a los antibióticos mostró un 100 % de sensibilidad a teicoplanina, gentamiclna y rifampicina; 2 aislamientos fueron resistentes a clindamicina y a eritromicina y 4 resultaron resistentes a la meticilina. Estos resultados son un alerta e indicarían la necesidad de desarrollar medidas racionales para reducir el riesgo potencial de intoxicaciones alimentarias.Staphylococcus aureus causes food poisoning due to its ability to produce enterotoxins. Food handlers carrying enterotoxin-producing S. aureus can contaminate food, thus leading to food poisoning. Samples were obtained from 88 food handlers in the Province of Misiones, Argentina. S. aureus was isolated from nasal swaps and PCR amplification was performed for genes encoding staphylococcal enterotoxins. A total of 37.5 % food handlers were positive for S. aureus. Expression of enterotoxin genes was found in 13 of the 33 (39.4 % S. aureus isolates studied, accounting for 14.7 % of food handlers. Gene sea was detected in 10 isolates followed by gene sec in 3 isolates. All isolates were susceptible to teicoplanin, gentamicin and rifampicin. Four isolates were resistant to methicillin whereas 2 isolates were resistant to clindamycin and erythromycin. These results constitute a critical alert and indicate the need

Síndrome de Aicardi: Descripción de cuatro casos venezolanos

OpenAIRE

Suárez-Villalobos, Pilar; Peña, Joaquín A; Calzadilla, Laura; Ruíz, María; Mora-La Cruz, Eduardo

2010-01-01

El síndrome de Aicardi (SA) se caracteriza por agenesia del cuerpo calloso, espasmos infantiles y lesiones lacunares coriorretinianas. Su espectro evolutivo es variable, con pronóstico habitualmente muy grave en los primeros cinco años de vida. El objetivo de este trabajo es describir el espectro del fenotipo clínico y evolución de este trastorno en cuatro pacientes venezolanos. Todas las pacientes evaluadas cumplieron los criterios diagnósticos mayores, mostraron retraso psicomotor grave y c...

Gene expression-based classifiers identify Staphylococcus aureus infection in mice and humans.

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Sun Hee Ahn

Full Text Available Staphylococcus aureus causes a spectrum of human infection. Diagnostic delays and uncertainty lead to treatment delays and inappropriate antibiotic use. A growing literature suggests the host's inflammatory response to the pathogen represents a potential tool to improve upon current diagnostics. The hypothesis of this study is that the host responds differently to S. aureus than to E. coli infection in a quantifiable way, providing a new diagnostic avenue. This study uses Bayesian sparse factor modeling and penalized binary regression to define peripheral blood gene-expression classifiers of murine and human S. aureus infection. The murine-derived classifier distinguished S. aureus infection from healthy controls and Escherichia coli-infected mice across a range of conditions (mouse and bacterial strain, time post infection and was validated in outbred mice (AUC>0.97. A S. aureus classifier derived from a cohort of 94 human subjects distinguished S. aureus blood stream infection (BSI from healthy subjects (AUC 0.99 and E. coli BSI (AUC 0.84. Murine and human responses to S. aureus infection share common biological pathways, allowing the murine model to classify S. aureus BSI in humans (AUC 0.84. Both murine and human S. aureus classifiers were validated in an independent human cohort (AUC 0.95 and 0.92, respectively. The approach described here lends insight into the conserved and disparate pathways utilized by mice and humans in response to these infections. Furthermore, this study advances our understanding of S. aureus infection; the host response to it; and identifies new diagnostic and therapeutic avenues.

Rhesus macaques (Macaca mulatta are natural hosts of specific Staphylococcus aureus lineages.

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Sanne van den Berg

Full Text Available Currently, there is no animal model known that mimics natural nasal colonization by Staphylococcus aureus in humans. We investigated whether rhesus macaques are natural nasal carriers of S. aureus. Nasal swabs were taken from 731 macaques. S. aureus isolates were typed by pulsed-field gel electrophoresis (PFGE, spa repeat sequencing and multi-locus sequence typing (MLST, and compared with human strains. Furthermore, the isolates were characterized by several PCRs. Thirty-nine percent of 731 macaques were positive for S. aureus. In general, the macaque S. aureus isolates differed from human strains as they formed separate PFGE clusters, 50% of the isolates were untypeable by agr genotyping, 17 new spa types were identified, which all belonged to new sequence types (STs. Furthermore, 66% of macaque isolates were negative for all superantigen genes. To determine S. aureus nasal colonization, three nasal swabs from 48 duo-housed macaques were taken during a 5 month period. In addition, sera were analyzed for immunoglobulin G and A levels directed against 40 staphylococcal proteins using a bead-based flow cytometry technique. Nineteen percent of the animals were negative for S. aureus, and 17% were three times positive. S. aureus strains were easily exchanged between macaques. The antibody response was less pronounced in macaques compared to humans, and nasal carrier status was not associated with differences in serum anti-staphylococcal antibody levels. In conclusion, rhesus macaques are natural hosts of S. aureus, carrying host-specific lineages. Our data indicate that rhesus macaques are useful as an autologous model for studying S. aureus nasal colonization and infection prevention.

Identification of the ClpX Regulon in Staphylococcus aureus

DEFF Research Database (Denmark)

Jelsbak, Lotte; Thomsen, Line Elnif; Ingmer, Hanne

Staphyloccous aureus is a major human pathogen capable of causing a wide spectrum of infections ranging from superficial wound infections to life-threatening endocarditis and toxic shock syndrome. Essential for S. aureus virulence is a large number of cell-surface-associated proteins and secreted...... we show here that almost 400 genes (15%) are influenced by the clpX deletion. Furthermore, ClpX not only regulates many virulence factors, but rather serves as a global regulator of central functions for S. aureus lifestyle and pathogenicity....

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus.

Science.gov (United States)

Zhang, Jing; Suo, Yujuan; Zhang, Daofeng; Jin, Fangning; Zhao, Hang; Shi, Chunlei

2018-01-01

Staphyloxanthin (STX), a golden carotenoid pigment produced by Staphylococcus aureus , is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to clarify the genetic and virulent differences between the two groups. Here, 132 S. aureus isolates were divided into two phenotype groups depending on the absorbance (OD 450 ) of the extracted carotenoids. Then, all isolates were subjected to spa typing and multilocus sequence typing (MLST), and then the detection of presence of 30 virulence factors and the gene integrity of crtN and crtM . Furthermore, 24 typical S. aureus isolates and 4 S. argenteus strains were selected for the murine infection assay of in vivo virulence, in which the histological observation and enumeration of CFUs were carried out. These isolates were distributed in 26 sequence types (STs) and 49 spa types. The pigmented isolates were scattered in 25 STs, while the non-pigmented isolates were more centralized, which mainly belonged to ST20 (59%) and ST25 (13%). Among the 54 non-pigmented isolates, about 20% carried intact crtN and crtM genes. The in vivo assay suggested that comparing with pigmented S. aureus , non-pigmented S. aureus and S. argenteus strains did not show a reduced virulence in murine sepsis models. Therefore, it suggested that there were no significant genetic and virulent differences between pigmented and non-pigmented S. aureus .

Dehydrosqualene Desaturase as a Novel Target for Anti-Virulence Therapy against Staphylococcus aureus

Directory of Open Access Journals (Sweden)

Peng Gao

2017-09-01

Full Text Available Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA, is a life-threatening pathogen in hospital- and community-acquired infections. The golden-colored carotenoid pigment of S. aureus, staphyloxanthin, contributes to the resistance to reactive oxygen species (ROS and host neutrophil-based killing. Here, we describe a novel inhibitor (NP16 of S. aureus pigment production that reduces the survival of S. aureus under oxidative stress conditions. Carotenoid components analysis, enzyme inhibition, and crtN mutational studies indicated that the molecular target of NP16 is dehydrosqualene desaturase (CrtN. S. aureus treated with NP16 showed increased susceptibility to human neutrophil killing and to innate immune clearance in a mouse infection model. Our study validates CrtN as a novel druggable target in S. aureus and presents a potent and effective lead compound for the development of virulence factor-based therapy against S. aureus.

Colonization and biofilm formation by Staphylococcus aureus on endothelial cell layers under flow

DEFF Research Database (Denmark)

Grønnemose, Rasmus Birkholm; Antoinette Asferg, Cecilie; Kolmos, Hans Jørn

Staphylococcus aureus is a major human pathogen and known for causing vascular infections such as sepsis and infective endocarditis. It has previously been proposed that S. aureus succeed in colonization of the endothelial wall by specific surface attachment likely followed by biofilm formation....... Furthermore, S. aureus is known to invade human cells, which has been proposed to promote persistence through immune and antibiotic evasion. In the current study, we sought to investigate endothelial colonization, invasion, and biofilm formation by S. aureus using a newly developed in vitro flow chamber model....... We show that under physiological shear rates, S. aureus utilizes cellular invasion to enable the following surface colonization and biofilm formation. These observations might help explain the success of S. aureus as a bloodstream pathogen and guide further studies in S. aureus pathogenesis...

Antimicrobial activity of Lactobacillus salivarius and Lactobacillus fermentum against Staphylococcus aureus.

Science.gov (United States)

Kang, Mi-Sun; Lim, Hae-Soon; Oh, Jong-Suk; Lim, You-Jin; Wuertz-Kozak, Karin; Harro, Janette M; Shirtliff, Mark E; Achermann, Yvonne

2017-03-01

The increasing prevalence of methicillin-resistant Staphylococcus aureus has become a major public health threat. While lactobacilli were recently found useful in combating various pathogens, limited data exist on their therapeutic potential for S. aureus infections. The aim of this study was to determine whether Lactobacillus salivarius was able to produce bactericidal activities against S. aureus and to determine whether the inhibition was due to a generalized reduction in pH or due to secreted Lactobacillus product(s). We found an 8.6-log10 reduction of planktonic and a 6.3-log10 reduction of biofilm S. aureus. In contrast, the previously described anti-staphylococcal effects of L. fermentum only caused a 4.0-log10 reduction in planktonic S. aureus cells, with no effect on biofilm S. aureus cells. Killing of S. aureus was partially pH dependent, but independent of nutrient depletion. Cell-free supernatant that was pH neutralized and heat inactivated or proteinase K treated had significantly reduced killing of L. salivarius than with pH-neutralized supernatant alone. Proteomic analysis of the L. salivarius secretome identified a total of five secreted proteins including a LysM-containing peptidoglycan binding protein and a protein peptidase M23B. These proteins may represent potential novel anti-staphylococcal agents that could be effective against S. aureus biofilms. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Comparison of five tests for identification of Staphylococcus aureus from clinical samples

NARCIS (Netherlands)

A. Luijendijk (Ad); A.F. van Belkum (Alex); J.A.J.W. Kluytmans (Jan); H.A. Verbrugh (Henri)

1996-01-01

textabstractFive different laboratory tests for the identification of Staphylococcus aureus were compared. Analyses of 271 presumptive S. aureus strains, supplemented with 59 well-defined methicillin-resistant S. aureus (MRSA) isolates, were performed. Only the

Antibiotic tolerance and the alternative lifestyles of Staphylococcus aureus.

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Bui, Long M G; Conlon, Brian P; Kidd, Stephen P

2017-02-28

Staphylococcus aureus has an incredible ability to survive, either by adapting to environmental conditions or defending against exogenous stress. Although there are certainly important genetic traits, in part this ability is provided by the breadth of modes of growth S. aureus can adopt. It has been proposed that while within their host, S. aureus survives host-generated and therapeutic antimicrobial stress via alternative lifestyles: a persister sub-population, through biofilm growth on host tissue or by growing as small colony variants (SCVs). Key to an understanding of chronic and relapsing S. aureus infections is determining the molecular basis for its switch to these quasi-dormant lifestyles. In a multicellular biofilm, the metabolically quiescent bacterial community additionally produces a highly protective extracellular polymeric substance (EPS). Furthermore, there are bacteria within a biofilm community that have an altered physiology potentially equivalent to persister cells. Recent studies have directly linked the cellular ATP production by persister cells as their key feature and the basis for their tolerance of a range of antibiotics. In clinical settings, SCVs of S. aureus have been observed for many years; when cultured, these cells form non-pigmented colonies and are approximately ten times smaller than their counterparts. Various genotypic factors have been identified in attempts to characterize S. aureus SCVs and different environmental stresses have been implicated as important inducers. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

A porcine model of haematogenous brain infectionwith staphylococcus aureus

DEFF Research Database (Denmark)

Astrup, Lærke Boye; Agerholm, Jørgen Steen; Nielsen, Ole Lerberg

2012-01-01

A PORCINE MODEL OF HAEMATOGENOUS BRAIN INFECTION WITH STAPHYLOCOCCUS AUREUS Astrup Lærke1, Agerholm Jørgen1, Nielsen Ole1, Jensen Henrik1, Leifsson Páll1, Iburg Tine2. 1: Faculty of Health and Medical Sciences, University of Copenhagen, Denmark boye@life.ku.dk 2: National Veterinary Institute......, Uppsala, Sweden Introduction Staphylococcus aureus (S.aureus) is a common cause of sepsis and brain abscesses in man and a frequent cause of porcine pyaemia. Here we present a porcine model of haematogenous S. aureus-induced brain infection. Materials and Methods Four pigs had two intravenous catheters...... thromboemboli (two pigs). The venous catheter was used for blood sampling before, during and after inoculation. The pigs were euthanized either 24 or 48 hours after inoculation. The brains were collected and examined histologically. Results We describe unifocal suppurative encephalitis 48 hours after...

Staphylococcus aureus produces membrane-derived vesicles that induce host cell death.

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Mamata Gurung

Full Text Available Gram-negative bacteria produce outer membrane vesicles that play a role in the delivery of virulence factors to host cells. However, little is known about the membrane-derived vesicles (MVs produced by gram-positive bacteria. The present study examined the production of MVs from Staphylococcus aureus and investigated the delivery of MVs to host cells and subsequent cytotoxicity. Four S. aureus strains tested, two type strains and two clinical isolates, produced spherical nanovesicles during in vitro culture. MVs were also produced during in vivo infection of a clinical S. aureus isolate in a mouse pneumonia model. Proteomic analysis showed that 143 different proteins were identified in the S. aureus-derived MVs. S. aureus MVs were interacted with the plasma membrane of host cells via a cholesterol-rich membrane microdomain and then delivered their component protein A to host cells within 30 min. Intact S. aureus MVs induced apoptosis of HEp-2 cells in a dose-dependent manner, whereas lysed MVs neither delivered their component into the cytosol of host cells nor induced cytotoxicity. In conclusion, this study is the first report that S. aureus MVs are an important vehicle for delivery of bacterial effector molecules to host cells.

Dehydrosqualene Desaturase as a Novel Target for Anti-Virulence Therapy against Staphylococcus aureus.

Science.gov (United States)

Gao, Peng; Davies, Julian; Kao, Richard Yi Tsun

2017-09-05

Staphylococcus aureus , especially methicillin-resistant S. aureus (MRSA), is a life-threatening pathogen in hospital- and community-acquired infections. The golden-colored carotenoid pigment of S. aureus , staphyloxanthin, contributes to the resistance to reactive oxygen species (ROS) and host neutrophil-based killing. Here, we describe a novel inhibitor (NP16) of S. aureus pigment production that reduces the survival of S. aureus under oxidative stress conditions. Carotenoid components analysis, enzyme inhibition, and crtN mutational studies indicated that the molecular target of NP16 is dehydrosqualene desaturase (CrtN). S. aureus treated with NP16 showed increased susceptibility to human neutrophil killing and to innate immune clearance in a mouse infection model. Our study validates CrtN as a novel druggable target in S. aureus and presents a potent and effective lead compound for the development of virulence factor-based therapy against S. aureus IMPORTANCE S. aureus staphyloxanthin contributes substantially to pathogenesis by interfering with host immune clearance mechanisms, but it has little impact on ex vivo survival of the bacterium. Agents blocking staphyloxanthin production may discourage the establishment and maintenance of bacterial infection without exerting selective pressure for antimicrobial resistance. Our newly discovered CrtN inhibitor, NP16, may offer an effective strategy for combating S. aureus infections. Copyright © 2017 Gao et al.

Emergence of Sequence Type 779 Methicillin-Resistant Staphylococcus aureus Harboring a Novel Pseudo Staphylococcal Cassette Chromosome mec (SCCmec)-SCC-SCCCRISPR Composite Element in Irish Hospitals

Science.gov (United States)

Kinnevey, Peter M.; Shore, Anna C.; Brennan, Grainne I.; Sullivan, Derek J.; Ehricht, Ralf; Monecke, Stefan; Slickers, Peter

2013-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) has been a major cause of nosocomial infection in Irish hospitals for 4 decades, and replacement of predominant MRSA clones has occurred several times. An MRSA isolate recovered in 2006 as part of a larger study of sporadic MRSA exhibited a rare spa (t878) and multilocus sequence (ST779) type and was nontypeable by PCR- and DNA microarray-based staphylococcal cassette chromosome mec (SCCmec) element typing. Whole-genome sequencing revealed the presence of a novel 51-kb composite island (CI) element with three distinct domains, each flanked by direct repeat and inverted repeat sequences, including (i) a pseudo SCCmec element (16.3 kb) carrying mecA with a novel mec class region, a fusidic acid resistance gene (fusC), and two copper resistance genes (copB and copC) but lacking ccr genes; (ii) an SCC element (17.5 kb) carrying a novel ccrAB4 allele; and (iii) an SCC element (17.4 kb) carrying a novel ccrC allele and a clustered regularly interspaced short palindromic repeat (CRISPR) region. The novel CI was subsequently identified by PCR in an additional 13 t878/ST779 MRSA isolates, six from bloodstream infections, recovered between 2006 and 2011 in 11 hospitals. Analysis of open reading frames (ORFs) carried by the CI showed amino acid sequence similarity of 44 to 100% to ORFs from S. aureus and coagulase-negative staphylococci (CoNS). These findings provide further evidence of genetic transfer between S. aureus and CoNS and show how this contributes to the emergence of novel SCCmec elements and MRSA strains. Ongoing surveillance of this MRSA strain is warranted and will require updating of currently used SCCmec typing methods. PMID:23147725

Emergence of sequence type 779 methicillin-resistant Staphylococcus aureus harboring a novel pseudo staphylococcal cassette chromosome mec (SCCmec)-SCC-SCCCRISPR composite element in Irish hospitals.

LENUS (Irish Health Repository)

Kinnevey, Peter M

2013-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) has been a major cause of nosocomial infection in Irish hospitals for 4 decades, and replacement of predominant MRSA clones has occurred several times. An MRSA isolate recovered in 2006 as part of a larger study of sporadic MRSA exhibited a rare spa (t878) and multilocus sequence (ST779) type and was nontypeable by PCR- and DNA microarray-based staphylococcal cassette chromosome mec (SCCmec) element typing. Whole-genome sequencing revealed the presence of a novel 51-kb composite island (CI) element with three distinct domains, each flanked by direct repeat and inverted repeat sequences, including (i) a pseudo SCCmec element (16.3 kb) carrying mecA with a novel mec class region, a fusidic acid resistance gene (fusC), and two copper resistance genes (copB and copC) but lacking ccr genes; (ii) an SCC element (17.5 kb) carrying a novel ccrAB4 allele; and (iii) an SCC element (17.4 kb) carrying a novel ccrC allele and a clustered regularly interspaced short palindromic repeat (CRISPR) region. The novel CI was subsequently identified by PCR in an additional 13 t878\\/ST779 MRSA isolates, six from bloodstream infections, recovered between 2006 and 2011 in 11 hospitals. Analysis of open reading frames (ORFs) carried by the CI showed amino acid sequence similarity of 44 to 100% to ORFs from S. aureus and coagulase-negative staphylococci (CoNS). These findings provide further evidence of genetic transfer between S. aureus and CoNS and show how this contributes to the emergence of novel SCCmec elements and MRSA strains. Ongoing surveillance of this MRSA strain is warranted and will require updating of currently used SCCmec typing methods.

New epidemiology of Staphylococcus aureus infection in Asia.

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Chen, C-J; Huang, Y-C

2014-07-01

Not only is Asia the most populous region in the world, but inappropriate therapy, including self-medication with over-the-counter antimicrobial agents, is a common response to infectious diseases. The high antibiotic selective pressure among the overcrowded inhabitants creates an environment that is suitable for the rapid development and efficient spread of numerous multidrug-resistant pathogens. Indeed, Asia is among the regions with the highest prevalence rates of healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and community-associated methicillin-resistant S. aureus (CA-MRSA) in the world. Most hospitals in Asia are endemic for multidrug-resistant methicillin-resistant S. aureus (MRSA), with an estimated proportion from 28% (in Hong Kong and Indonesia) to >70% (in Korea) among all clinical S. aureus isolates in the early 2010s. Isolates with reduced susceptibility or a high level of resistance to glycopeptides have also been increasingly identified in the past few years. In contrast, the proportion of MRSA among community-associated S. aureus infections in Asian countries varies markedly, from 35%. Two pandemic HA-MRSA clones, namely multilocus sequence type (ST) 239 and ST5, are disseminated internationally in Asia, whereas the molecular epidemiology of CA-MRSA in Asia is characterized by clonal heterogeneity, similar to that in Europe. In this review, the epidemiology of S. aureus in both healthcare facilities and communities in Asia is addressed, with an emphasis on the prevalence, clonal structure and antibiotic resistant profiles of the MRSA strains. The novel MRSA strains from livestock animals have been considered to constitute a public health threat in western countries. The emerging livestock-associated MRSA strains in Asia are also included in this review. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

Molecular basis of virulence in Staphylococcus aureus mastitis.

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Caroline Le Maréchal

Full Text Available S. aureus is one of the main pathogens involved in ruminant mastitis worldwide. The severity of staphylococcal infection is highly variable, ranging from subclinical to gangrenous mastitis. This work represents an in-depth characterization of S. aureus mastitis isolates to identify bacterial factors involved in severity of mastitis infection.We employed genomic, transcriptomic and proteomic approaches to comprehensively compare two clonally related S. aureus strains that reproducibly induce severe (strain O11 and milder (strain O46 mastitis in ewes. Variation in the content of mobile genetic elements, iron acquisition and metabolism, transcriptional regulation and exoprotein production was observed. In particular, O11 produced relatively high levels of exoproteins, including toxins and proteases known to be important in virulence. A characteristic we observed in other S. aureus strains isolated from clinical mastitis cases.Our data are consistent with a dose-dependant role of some staphylococcal factors in the hypervirulence of strains isolated from severe mastitis. Mobile genetic elements, transcriptional regulators, exoproteins and iron acquisition pathways constitute good targets for further research to define the underlying mechanisms of mastitis severity.

Metastatic Spreading of Community Acquired Staphylococcus aureus Bacteraemia

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Giovanna Fabio

2011-01-01

Full Text Available A 29-year-old woman presented to the Fondazione IRCCS “Cà Granda” Ospedale Maggiore, a tertiary care university hospital in Milan (Italy, with skin lesions, fever, myalgia, joint pain and swelling, and a one-week history of low back pain. The diagnosis was Staphylococcus aureus (S. aureus bacteraemia spreading to skin, bones, and joints and a lumbosacral epidural abscess L5-S2. Neither initial focus nor predisposing conditions were apparent. The antibiotic therapy was prolonged for six-weeks with the resolution of fever, skin lesions, articular inflammation, and the epidural abscess. Community-acquired S. aureus infections can affect patients without traditional healthcare-associated risk factors, and community acquisition is a risk-factor for the development of complications. Raised awareness of S. aureus bacteraemia, also in patients without healthcare-associated risk factors, is important in the diagnosis, management, and control of this infection, because failure to recognise patients with serious infection and lack of understanding of empirical antimicrobial selection are associated with a high mortality rate in otherwise healthy people.

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus

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Jing Zhang

2018-04-01

Full Text Available Staphyloxanthin (STX, a golden carotenoid pigment produced by Staphylococcus aureus, is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to clarify the genetic and virulent differences between the two groups. Here, 132 S. aureus isolates were divided into two phenotype groups depending on the absorbance (OD450 of the extracted carotenoids. Then, all isolates were subjected to spa typing and multilocus sequence typing (MLST, and then the detection of presence of 30 virulence factors and the gene integrity of crtN and crtM. Furthermore, 24 typical S. aureus isolates and 4 S. argenteus strains were selected for the murine infection assay of in vivo virulence, in which the histological observation and enumeration of CFUs were carried out. These isolates were distributed in 26 sequence types (STs and 49 spa types. The pigmented isolates were scattered in 25 STs, while the non-pigmented isolates were more centralized, which mainly belonged to ST20 (59% and ST25 (13%. Among the 54 non-pigmented isolates, about 20% carried intact crtN and crtM genes. The in vivo assay suggested that comparing with pigmented S. aureus, non-pigmented S. aureus and S. argenteus strains did not show a reduced virulence in murine sepsis models. Therefore, it suggested that there were no significant genetic and virulent differences between pigmented and non-pigmented S. aureus.

Caracterización de tilapia roja (Oreochromis sp. con marcadores moleculares RAPD

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Muñoz Jaime Eduardo

2010-06-01

Full Text Available Se utilizó la técnica RAPD (amplificación al azar de ADN polimórfico para el estudio de la diversidad genética de Oreochromis sp. (tilapia roja en cinco piscícolas del Valle del Cauca (Colombia y en la determinación del nivel de introgresión de las especies parentales Oreochromis mosambicus, O. niloticus y O. aureus. Se evaluaron 25 cebadores, ocho fueron polimórficos y se obtuvieron 109 bandas. Los valores de heterocigosidad esperada (0.196 a 0.256 y la estructura genética (G_st = 0.22 para Oreochromis sp. indicaron un elevado grado de polimorfismo y alta estructuración genética. Estos resultados fueron consistente con el F_st = 0.268 (P < 0.0001 dado por el Amova y el G_st = 0.040 del análisis de correspondencia múltiple. Los valores de similitud genética, el análisis de grupo, el análisis de correspondencia múltiple y el nivel de introgresion, indicaron diferencias significativas (P<0.0001 en los niveles de introgresión. El bajo nivel de diferenciación genética entre poblaciones podría ser el resultado de peces con el mismo origen genético y la alta variación dentro de poblaciones se puede presentar por prácticas de manejo. La introgresión entre piscícolas es significativa para O. aureus, mientras que las especies O. niloticus y O. mosambicus se encuentran introgresadas de forma similar en las poblaciones de Oreochromis sp.

Prevalence of Staphylococcus aureus and of methicillin-resistant S. aureus clonal complexes in bulk tank milk from dairy cattle herds in Lombardy Region (Northern Italy).

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Cortimiglia, C; Luini, M; Bianchini, V; Marzagalli, L; Vezzoli, F; Avisani, D; Bertoletti, M; Ianzano, A; Franco, A; Battisti, A

2016-10-01

Staphylococcus aureus is the most important causative agent of subclinical mastitis in cattle resulting in reduced milk production and quality. Methicillin-resistant S. aureus (MRSA) strains has a clear zoonotic relevance, especially in the case of occupational exposure. The aim of the study was to evaluate the prevalence of S. aureus and MRSA in bulk tank milk (BTM) from dairy cattle herds in the Lombardy Region (Northern Italy) and to identify the main MRSA circulating genotypes. MRSA strains were characterized by susceptibility testing, multi-locus sequence typing (MLST), spa typing and SCCmec typing. A total 844 BTM samples were analysed and S. aureus and MRSA were detected in 47·2% and 3·8% of dairy herds, respectively. MLST showed that the majority (28/32) of isolates belonged to the typical livestock-associated lineages: ST398, ST97 and ST1. Interestingly, in this study we report for the first time the new ST3211, a single locus variant of ST(CC)22, with the newly described 462 aroE allele. Our study indicates high diffusion of S. aureus mastitis and low, but not negligible, prevalence of MRSA in the considered area, suggesting the need for planning specific control programmes for bovine mastitis caused by S. aureus, especially when MRSA is implicated.

Lucky number seven: RNase 7 can prevent Staphylococcus aureus skin colonization.

Science.gov (United States)

Cho, John S; Xuan, Caiyun; Miller, Lloyd S

2010-12-01

Staphylococcus aureus colonization is a major risk factor for infection. In this issue, Simanski et al. demonstrate that the antimicrobial peptide RNase 7 is essential for preventing S. aureus colonization in human skin. These findings suggest that therapeutic interventions aimed at targeting RNase 7 production in the skin may be a novel strategy to protect against S. aureus infections.

Nasal carriage of multi-drug resistant Staphylococcus aureus in ...

African Journals Online (AJOL)

Background: Nasal Staphylococcus aureus is a major source of community and hospital associated staphylococcal infections. This study determined the prevalence of nasal S. aureus isolates and investigated their antimicrobial resistance profile in healthy volunteers. Methods: Nasal specimens of healthy volunteers in ...

Staphylococcus aureus colonization in atopic eczema and its association with filaggrin gene mutations

DEFF Research Database (Denmark)

Clausen, M. L.; Edslev, S. M.; Andersen, P. S.

2017-01-01

was to assess differences in S. aureus colonization in patients with AD with and without filaggrin gene mutations. The secondary aim was to assess disease severity in relation to S. aureus colonization. Exploratory analyses were performed to investigate S. aureus genetic lineages in relation to filaggrin gene...... were characterized with respect to disease severity (Scoring Atopic Dermatitis) and FLG mutations (n = 88). Fisher's exact test was used to analyse differences in S. aureus colonization in relation to FLG mutations. Results: Of the 101 patients included, 74 (73%) were colonized with S. aureus....... Of the colonized patients, 70 (95%) carried only one CC type in all three different sampling sites. In lesional skin, S. aureus was found in 24 of 31 patients with FLG mutations vs. 24 of 54 wild-type patients (P = 0·0004). Staphylococcus aureusCC1 clonal lineage was more prevalent in patients with FLG mutations...

The molecular changing mechanism of Ampicillin-Sulbactam resistant Staphylococcus aureus towards Methicillin resistant Staphylococcus aureus

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Mieke Hemiawati Satari

2005-12-01

Full Text Available The aim of this study was to determine the molecular changing of S.aureus, which is resistant to Ampicillin-Sulbactam and then become resistant to Methicillin as a result of improper dosage. The study was conducted by isolating Ampicillin-Sulbactam resistant and Methicillin Resistant S.aureus (MRSA, afterwards an amplification process was performed by PCR (Polymerase Chain Reaction. to isolate the betalactamase enzyme regulator and PBP 2a genes. The result of this research showed that there were a deletion of few amino acids from the regulator gene, and a suspicion that the DNA sequence had been substituted from PBP 2 gene into PBP 2a (gen mec. This process had formed MRSA.

Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer.

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Amissah, Nana Ama; Chlebowicz, Monika A; Ablordey, Anthony; Sabat, Artur J; Tetteh, Caitlin S; Prah, Isaac; van der Werf, Tjip S; Friedrich, Alex W; van Dijl, Jan Maarten; Rossen, John W; Stienstra, Ymkje

2015-01-01

Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere(+) software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance. SeqSphere(+) analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus.

Low Efficacy of Antibiotics Against Staphylococcus aureus Airway Colonization in Ventilated Patients.

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Stulik, Lukas; Hudcova, Jana; Craven, Donald E; Nagy, Gabor; Nagy, Eszter

2017-04-15

Airway-colonization by Staphylococcus aureus predisposes to the development of ventilator-associated tracheobronchitis (VAT) and ventilator-associated pneumonia (VAP). Despite extensive antibiotic treatment of intensive care unit patients, limited data are available on the efficacy of antibiotics on bacterial airway colonization and/or prevention of infections. Therefore, microbiologic responses to antibiotic treatment were evaluated in ventilated patients. Results of semiquantitative analyses of S. aureus burden in serial endotracheal-aspirate (ETA) samples and VAT/VAP diagnosis were correlated to antibiotic treatment. Minimum inhibitory concentrations of relevant antibiotics using serially collected isolates were evaluated. Forty-eight mechanically ventilated patients who were S. aureus positive by ETA samples and treated with relevant antibiotics for at least 2 consecutive days were included in the study. Vancomycin failed to reduce methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus (MSSA) burden in the airways. Oxacillin was ineffective for MSSA colonization in approximately 30% of the patients, and responders were typically coadministered additional antibiotics. Despite antibiotic exposure, 15 of the 39 patients (approximately 38%) colonized only by S. aureus and treated with appropriate antibiotic for at least 2 days still progressed to VAP. Importantly, no change in antibiotic susceptibility of S. aureus isolates was observed during treatment. Staphylococcus aureus colonization levels inversely correlated with the presence of normal respiratory flora. Antibiotic treatment is ineffective in reducing S. aureus colonization in the lower airways and preventing VAT or VAP. Staphylococcus aureus is in competition for colonization with the normal respiratory flora. To improve patient outcomes, alternatives to antibiotics are urgently needed. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of

Persistent environmental contamination with USA300 methicillin-resistant Staphylococcus aureus and other pathogenic strain types in households with S. aureus skin infections.

Science.gov (United States)

Eells, Samantha J; David, Michael Z; Taylor, Alexis; Ortiz, Nancy; Kumar, Neha; Sieth, Julia; Boyle-Vavra, Susan; Daum, Robert S; Miller, Loren G

2014-11-01

To understand the genotypic spectrum of environmental contamination of Staphylococcus aureus in households and its persistence. Prospective longitudinal cohort investigation. Index participants identified at 2 academic medical centers. Adults and children with S. aureus skin infections and their household contacts in Los Angeles and Chicago. Household fomites were surveyed for contamination at baseline and 3 months. All isolates underwent genetic typing. We enrolled 346 households, 88% of which completed the 3-month follow-up visit. S. aureus environmental contamination was 49% at baseline and 51% at 3 months. Among households with a USA300 methicillin-resistant S. aureus (MRSA) body infection isolate, environmental contamination with an indistinguishable MRSA strain was 58% at baseline and 63% at 3 months. Baseline factors associated with environmental contamination by the index subject's infection isolate were body colonization by any household member with the index subject's infection isolate at baseline (odds ratio [OR], 10.93 [95% confidence interval (CI), 5.75-20.79]), higher housing density (OR, 1.47 [95% CI, 1.10-1.96]), and more frequent household fomite cleaning (OR, 1.62 [95% CI, 1.16-2.27]). Household environmental contamination with the index subject's infection strain at 3 months was associated with USA300 MRSA and a synergistic interaction between baseline environmental contamination and body colonization by any household member with the index subject's infection strain. We found that infecting S. aureus isolates frequently persisted environmentally in households 3 months after skin infection. Presence of pathogenic S. aureus strain type in the environment in a household may represent a persistent reservoir that places household members at risk of future infection.

Antimicrobial activity of some sulfonamide derivatives on clinical isolates of Staphylococus aureus

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Bekdemir Yunus

2008-08-01

Full Text Available Abstract Background Staphylococcus aureus is a non-motile, gram positive, non-sporforming, facultative anaerobic microorganism. It is one of the important bacteria as a potential pathogen specifically for nosocomial infections. The sulfonamide derivative medicines are preferred to cure infection caused by S. aureus due to methicillin resistance. Methods Antimicrobial activity of four sulfonamide derivatives have been investigated against 50 clinical isolates of S. aureus and tested by using MIC and disc diffusion methods. 50 clinical isolate which collected from specimens of patients who are given medical treatment in Ondokuz Mayis University Medical School Hospital. A control strain of S. aureus ATCC 29213 was also tested. Results The strongest inhibition was observed in the cases of I [N-(2-hydroxy-4-nitro-phenyl-4-methyl-benzensulfonamid], and II [N-(2-hydroxy-5-nitro-phenyl-4-methyl-benzensulfonamid] against S. aureus. Compound I [N-(2-hydroxy-4-nitro-phenyl-4-methyl-benzensulfonamid] showed higher effect on 21 S. aureus MRSAisolates than oxacillin antibiotic. Introducing an electron withdrawing on the ring increased the antimicrobial activity remarkably. Conclusion This study may help to suggest an alternative possible leading compound for development of new antimicrobial agents against MRSA and MSSA resistant S. aureus. It was also shown here that that clinical isolates of 50 S. aureus have various resistance patterns against to four sulfonamide derivatives. It may also be emphasized here that in vitro antimicrobial susceptibility testing results for S. aureus need standardization with further studies and it should also have a correlation with in vivo therapeutic response experiments.

Staphylococcus aureus and the ecology of the nasal microbiome

DEFF Research Database (Denmark)

Liu, Cindy M; Price, Lance B; Hungate, Bruce A

2015-01-01

The human microbiome can play a key role in host susceptibility to pathogens, including in the nasal cavity, a site favored by Staphylococcus aureus. However, what determines our resident nasal microbiota-the host or the environment-and can interactions among nasal bacteria determine S. aureus...

Effect of temperature on antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa.

Science.gov (United States)

Taki, Y; Seki, K; Ikigai, H; Nishihara, S; Ueno, H; Murota, K; Masuda, S

1988-01-01

The effect of temperature on the antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa was investigated in vitro. At 10 C at which S. aureus organisms do not grow and might be metabolically inactive, the antibacterial activity of lidocaine to S. aureus was not observed in a concentration of 1%, which was quite antibacterial to S. aureus at 37 C. On the other hand, at 40 C a conspicuously increased antibacterial activity to S. aureus of lidocaine was observed in a concentration of 0.25% which was not antibacterial to S. aureus organisms at 37 C. Similar results were obtained when P. aeruginosa organisms were examined in place of S. aureus, although P. aeruginosa was found to be less susceptible to lidocaine than S. aureus. The clinical significance of the thermal effect on the antibacterial activity of lidocaine was discussed in brief.

Risk factors for Staphylococcus aureus nasal colonization in Danish middle-aged and elderly twins

DEFF Research Database (Denmark)

Andersen, P S; Larsen, Lisbeth Aagaard; Fowler, V G

2013-01-01

on S. aureus carriage in Danish middle-aged and elderly twins, which indicated no significant heritability that could account for the observed S. aureus carriage. In the present study, we performed a questionnaire-based study of S. aureus colonization on the same cohort of 2,196 Danish middle......-aged and elderly twins to identify specific risk factors for S. aureus nasal colonization, including analyzing the paired twins (n = 478) that were discordant for S. aureus colonization. We found associations between risk factors and S. aureus nasal colonization among middle-aged and elderly twins, including age......, male gender, psoriasis, and atopic diseases. Also, present living on a farm is clearly associated with S. aureus colonization, while smoking had a borderline statistically significant protective effect....

Prevalence of Staphylococcus aureus in Shrimps in Tehran during 2013

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Mohammad Mehdi Soltan Dallal

2015-12-01

Full Text Available Background During fishing and transport, preservation and quality of fish products are importantas well as storage to prevent the growth of pathogenic and toxin producing bacteria.Staphylococcus aureus is one of the most common causes of sea food-borne diseases worldwidedue to contamination of food by preformed enterotoxins. The aim of this study was to compare theprevalence and contamination of S. aureus in marine and farmed shrimps in Tehran fishery center.Methods: A total of 300 samples, including 150 marine, 150 farmed shrimps were selected duringSeptember 2013 to December 2013. Isolation and identification of S. aureus from isolated sampleswere carried out according to conventional methods, and antibiotic susceptibility test wasperformed by modified Kirby-Bauer disc diffusion methodResults: The results of this study showed that 30% of marine and 20% off armed shrimps werecontaminated with S. aureus. The highest resistance was observed with penicillin and ampicillin,whereas 100% were sensitive to vancomycin, clindamycin, ciprofloxacin, and rifampin.Conclusions: Due to relatively high contamination of shrimp by S. aureus more attention shouldbe given during processing and manufacturing.

Prevalence of Staphylococcus aureus in Shrimps in Tehran during 2013

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Mohammad Mehdi Soltan Dallal

2016-02-01

Full Text Available Background During fishing and transport, preservation and quality of fish products are importantas well as storage to prevent the growth of pathogenic and toxin producing bacteria.Staphylococcus aureus is one of the most common causes of sea food-borne diseases worldwidedue to contamination of food by preformed enterotoxins. The aim of this study was to compare theprevalence and contamination of S. aureus in marine and farmed shrimps in Tehran fishery center.Methods: A total of 300 samples, including 150 marine, 150 farmed shrimps were selected duringSeptember 2013 to December 2014. Isolation and identification of S. aureus from isolated sampleswere carried out according to conventional methods, and antibiotic susceptibility test wasperformed by modified Kirby-Bauer disc diffusion method.Results: The results of this study showed that 30% of marine and 20% off armed shrimps werecontaminated with S. aureus. The highest resistance was observed with penicillin and ampicillin,whereas 100% were sensitive to vancomycin, clindamycin, ciprofloxacin, and rifampin.Conclusions: Due to relatively high contamination of shrimp by S. aureus more attention shouldbe given during processing and manufacturing.

Antibacterial Action of Curcumin against Staphylococcus aureus: A Brief Review

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Sin-Yeang Teow

2016-01-01

Full Text Available Curcumin, the major constituent of Curcuma longa L. (Zingiberaceae family or turmeric, commonly used for cooking in Asian cuisine, is known to possess a broad range of pharmacological properties at relatively nontoxic doses. Curcumin is found to be effective against Staphylococcus aureus (S. aureus. As demonstrated by in vitro experiment, curcumin exerts even more potent effects when used in combination with various other antibacterial agents. Hence, curcumin which is a natural product derived from plant is believed to have profound medicinal benefits and could be potentially developed into a naturally derived antibiotic in the future. However, there are several noteworthy challenges in the development of curcumin as a medicine. S. aureus infections, particularly those caused by the multidrug-resistant strains, have emerged as a global health issue and urgent action is needed. This review focuses on the antibacterial activities of curcumin against both methicillin-sensitive S. aureus (MSSA and methicillin-resistant S. aureus (MRSA. We also attempt to highlight the potential challenges in the effort of developing curcumin into a therapeutic antibacterial agent.

A sensitive gold nanoparticle-based colorimetric aptasensor for Staphylococcus aureus.

Science.gov (United States)

Yuan, Jinglei; Wu, Shijia; Duan, Nuo; Ma, Xiaoyuan; Xia, Yu; Chen, Jie; Ding, Zhansheng; Wang, Zhouping

2014-09-01

In this study, a gold nanoparticle-based colorimetric aptasensor for Staphylococcus aureus (S. aureus) using tyramine signal amplification (TSA) technology has been developed. First, the biotinylated aptamer specific for S. aureus was immobilized on the surface of the wells of the microtiter plate via biotin-avidin binding. Then, the target bacteria (S. aureus), biotinylated-aptamer-streptavidin-HRP conjugates, biotinylated tyramine, hydrogen peroxide and avidin-catalase were successively introduced into the wells of the microtiter plate. After that, the existing catalase consumed the hydrogen peroxide. Finally, the freshly prepared gold (III) chloride trihydrate was added, the color of the reaction production would be changed and the absorbance at 550 nm could be measured with a plate reader. Under optimized conditions, there was a linear relationship between the absorbance at 550 nm and the concentration of S. aureus over the range from 10 to 10(6) cfu mL(-1) (with an R² of 0.9947). The limit of the developed method was determined to be 9 cfu mL(-1). Copyright © 2014 Elsevier B.V. All rights reserved.

Cross-Talk between Staphylococcus aureus and Other Staphylococcal Species via the agr Quorum Sensing System

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Jaime Canovas

2016-11-01

Full Text Available Staphylococci are associated with both humans and animals. While most are non-pathogenic colonizers, Staphylococcus aureus is an opportunistic pathogen capable of causing severe infections. S. aureus virulence is controlled by the agr quorum sensing system responding to secreted auto-inducing peptides (AIPs sensed by AgrC, a two component histidine kinase. agr loci are found also in other staphylococcal species and for Staphylococcus epidermidis, the encoded AIP represses expression of agr regulated virulence genes in S. aureus. In this study we aimed to better understand the interaction between staphylococci and S. aureus, and show that this interaction may eventually lead to the identification of new anti-virulence candidates to target S. aureus infections. Here we show that culture supernatants of 37 out of 52 staphylococcal isolates representing 17 different species inhibit S. aureus agr. The dog pathogen, Staphylococcus schleiferi, expressed the most potent inhibitory activity and was active against all four agr classes found in S. aureus. By employing a S. aureus strain encoding a constitutively active AIP receptor we show that the activity is mediated via agr. Subsequent cloning and heterologous expression of the S. schleiferi AIP in S. aureus demonstrated that this molecule was likely responsible for the inhibitory activity, and further proof was provided when pure synthetic S. schleiferi AIP was able to completely abolish agr induction of an S. aureus reporter strain. To assess impact on S. aureus virulence, we co-inoculated S. aureus and S. schleiferi in vivo in the Galleria mellonella wax moth larva, and found that expression of key S. aureus virulence factors was abrogated. Our data show that the S. aureus agr locus is highly responsive to other staphylococcal species suggesting that agr is an inter-species communication system. Based on these results we speculate that interactions between S. aureus and other colonizing staphylococci

Staphylococcus aureus spa type t437

DEFF Research Database (Denmark)

Glasner, C; Pluister, G; Westh, H

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) belonging to the multilocus sequence type clonal complex 59 (MLST CC59) is the predominant community-associated MRSA clone in Asia. This clone, which is primarily linked with the spa type t437, has so far only been reported in low numbers among...... included. Most isolates were shown to be monophyletic with 98% of the isolates belonging to the single MLVA complex 621, to which nearly all included isolates from China also belonged. More importantly, all MLST-typed isolates belonged to CC59. Our study implies that the European S. aureus t437 population...

Incidence, trends and demographics of Staphylococcus aureus infections in Auckland, New Zealand, 2001-2011.

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Williamson, Deborah A; Lim, Alwin; Thomas, Mark G; Baker, Michael G; Roberts, Sally A; Fraser, John D; Ritchie, Stephen R

2013-12-03

New Zealand has a higher incidence of Staphylococcus aureus disease than other developed countries, with significant sociodemographic variation in incidence rates. In contrast to North America, the majority of disease is due to methicillin-susceptible S. aureus (MSSA), although relatively little is known about the comparative demographics of MSSA and methicillin-resistant S. aureus (MRSA) infections in New Zealand. Our objectives were to describe the trends, incidence and patient demographics of all S. aureus infections in patients presenting to our institution between 2001 and 2011, and compare the epidemiology of MSSA and MRSA infections. We identified all patients with S. aureus infections over the study period. A unique S. aureus infection was defined as the first positive S. aureus culture taken from the same patient within a thirty-day period. Standard definitions were used to classify episodes into community- or healthcare-associated S. aureus infection. There were 16,249 S. aureus infections over the study period. The incidence increased significantly over the study period from 360 to 412 per 100,000 population (P New Zealand. The significant increase in community-associated S. aureus infections is of public health importance. Future studies should investigate the reasons underlying this concerning trend.

Caracterización del fenotipo infectante de Bordetella Pertussis : Microbiología celular e inmunoproteómica aplicadas al estudio de su interacción con el hospedador

OpenAIRE

Pérez Vidakovics, María Laura Anabella

2007-01-01

La habilidad de un patógeno para interaccionar con su hospedador determina en gran medida su persistencia o éxito evolutivo. Dado que ni la inmunización ni la infección natural proveen inmunidad a largo plazo contra B. pertussis, y que la vacunación no evita la circulación de este patógeno, resulta evidente que B. pertussis es extraordinariamente exitosa en cuanto a su capacidad de supervivencia en el ambiente hostil del hospedador. Los datos epidemiológicos ponen de manifiesto que las vacuna...

Molecular characterization of vancomycin-intermediate Staphylococcus aureus isolates from Tehran

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Shahin Najar-Peerayeh

2016-09-01

Full Text Available Objective: To determine the prevalence and some genetic characteristics of clinical isolates of Staphylococcus aureus (S. aureus with reduced susceptibility to vancomycin. Methods: A total of 414 isolates of S. aureus were collected from clinical specimens from hospitals in Tehran. Vancomycin-intermediate S. aureus (VISA was determined by brain heart infusion agar containing 4 μg/mL vancomycin screening plate and confirmed via E-test. VISA isolates were analysed for vanA, vanB, mecA, staphylococcal cassette chromosome mec types, surface protein A (Spa types and agr specific groups. Results: Brain heart infusion agar containing 4 μg/mL vancomycin screening tests revealed that 17.14% (n = 71 of S. aureus isolates were VISA phenotype. Ten of the 71 isolates were confirmed by E-test method (minimal inhibitory concentration was 4 to 8 μg/mL. All VISA isolates were susceptible to linezolid and 6 isolates (60% were methicillin-resistant S. aureus. Five isolates belonged to agr Group II, 4 belonged to agr Group I and 1 belonged to agr Group III. Spa type t030, and staphylococcal cassette chromosome mec Type III were dominant among VISA isolates. Conclusions: This study provides further evidence of the global dissemination of VISA isolates and emphasizes to vancomycin susceptibility testing prior to antibiotic therapy.

Lóbulos frontales y funciones ejecutivas en transexuales

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Orozco Calderón,Gabriela; Ostrosky Shejet,Feggy

2012-01-01

Una persona transexual se define como aquella que presenta una incongruencia entre el fenotipo físico y la identidad de género. Existen transexuales nacidos hombres pero con identidad de género de mujer. Se ha propuesto que uno de los orígenes de esta condición radica en los efectos que las hormonas esteroides sexuales tienen sobre el desarrollo cerebral a nivel prenatal y es posible que afecten las funciones cognitivas como las funciones ejecutivas. El objetivo fue evaluar funciones ejecutiv...

Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer.

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Nana Ama Amissah

Full Text Available Buruli ulcer (BU is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus.This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere(+ software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance.SeqSphere(+ analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus.

Brain infection following experimental Staphylococcus aureus sepsis in pigs

DEFF Research Database (Denmark)

Astrup, Lærke Boye; Iburg, Tine Moesgaard; Nielsen, Ole Lerberg

2010-01-01

Introduction: Sepsis is a major problem in humans and both the incidence and mortality is increasing. Multiple microabcesses can be found in the brain of septic patients. Staphylococcus aureus is one of the most common causes of sepsis and brain abscesses. S. aureus is also a frequent cause...... of spontaneous porcine pyemia including endocarditis and associated brain lesions. We present a porcine model of haematogenous S. aureus induced brain infection. Materials and Methods: Twelve pigs received an intravenous injection of S. aureus of 108 CFU/kg body weight once at 0h or twice at 0h and 12h. Four...... pigs were kept as controls. The pigs were euthanized in groups of four at either 6, 12, 24 or 48 h post infection. The brain was collected from all the animals and examined histologically. Results: All the inoculated pigs developed sepsis and 7 out of 12 animals had microabscesses in the prosencephalon...

Resistência à mupirocina entre isolados de Staphylococcus aureus de profissionais de enfermagem Resistencia al mupirocin en cepas aisladas de Staphylococcus aureus de profesionales de enfermería Mupirocin-resistant Staphylococcus aureus in samples belonging to professional nurses

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Josely Pinto de Moura

2010-06-01

Full Text Available OBJETIVOS: Avaliar a colonização por Staphylococcus aureus sensíveis e resistentes à meticilina na saliva de profissionais de enfermagem e o perfil de resistência à mupirocina. MÉTODOS: Foram coletadas três amostras da saliva de 356 (94,2% profissionais participantes da pesquisa, totalizando 1.068 amostras processadas. Todos os aspectos éticos foram contemplados. A análise microbiológica compreendeu a identificação fenotípica, segundo normas do Clinical and Laboratory Standards Institute. RESULTADOS: Foram obtidos 73 indivíduos colonizados por Staphylococcus aureus na primeira coleta, 48 na segunda e 37 na terceira, somando 158 isolados de Staphylococcus aureus. Desses, 24 (15,2% eram resistentes à oxacilina e 30 resistentes à mupirocina (18,9%. A resistência à mupirocina foi observada de forma pronunciada nos Staphylococcus aureus metacilina resistente (MRSA; dos 24 MRSA, 17 (70,8% apresentaram-se resistentes a este antimicrobiano. CONCLUSÃO: Os resultados indicaram que a resistência à mupirocina é um importante problema, pois esse antibiótico é um excelente aliado nas medidas de controle das infecções de serviços de saúde.OBJETIVOS: Evaluar la colonización por Staphylococcus aureus sensibles y resistentes al meticilín en la saliva de profesionales de enfermería y, reconocer el perfil de resistencia a la mupirocina. MÉTODOS: Fueron recolectadas tres muestras de saliva de 356 (94,2% profesionales participantes de la investigación, totalizando 1.068 muestras procesadas. Todos los aspectos éticos fueron contemplados. El análisis microbiológico comprendió la identificación fenotípica, según normas del Clinical and Laboratory Standards Institute. RESULTADOS: Fueron obtenidos 73 individuos colonizados por Staphylococcus aureus en la primera recolección, 48 en la segunda y 37 en la tercera, sumando 158 muestras aisladas de Staphylococcus aureus. De esas, 24 (15,2% eran resistentes a la oxacilina y 30

Bacteriocins of Non-aureus Staphylococci Isolated from Bovine Milk

Science.gov (United States)

Carson, Domonique A.; Barkema, Herman W.; Naushad, Sohail

2017-01-01

ABSTRACT Non-aureus staphylococci (NAS), the bacteria most commonly isolated from the bovine udder, potentially protect the udder against infection by major mastitis pathogens due to bacteriocin production. In this study, we determined the inhibitory capability of 441 bovine NAS isolates (comprising 26 species) against bovine Staphylococcus aureus. Furthermore, inhibiting isolates were tested against a human methicillin-resistant S. aureus (MRSA) isolate using a cross-streaking method. We determined the presence of bacteriocin clusters in NAS whole genomes using genome mining tools, BLAST, and comparison of genomes of closely related inhibiting and noninhibiting isolates and determined the genetic organization of any identified bacteriocin biosynthetic gene clusters. Forty isolates from 9 species (S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. saprophyticus, S. sciuri, S. simulans, S. warneri, and S. xylosus) inhibited growth of S. aureus in vitro, 23 isolates of which, from S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. simulans, and S. xylosus, also inhibited MRSA. One hundred five putative bacteriocin gene clusters encompassing 6 different classes (lanthipeptides, sactipeptides, lasso peptides, class IIa, class IIc, and class IId) in 95 whole genomes from 16 species were identified. A total of 25 novel bacteriocin precursors were described. In conclusion, NAS from bovine mammary glands are a source of potential bacteriocins, with >21% being possible producers, representing potential for future characterization and prospective clinical applications. IMPORTANCE Mastitis (particularly infections caused by Staphylococcus aureus) costs Canadian dairy producers $400 million/year and is the leading cause of antibiotic use on dairy farms. With increasing antibiotic resistance and regulations regarding use, there is impetus to explore bacteriocins (bacterially produced antimicrobial peptides) for treatment and prevention of bacterial infections

Decrease of Staphylococcus aureus Virulence by Helcococcus kunzii in a Caenorhabditis elegans Model.

Science.gov (United States)

Ngba Essebe, Christelle; Visvikis, Orane; Fines-Guyon, Marguerite; Vergne, Anne; Cattoir, Vincent; Lecoustumier, Alain; Lemichez, Emmanuel; Sotto, Albert; Lavigne, Jean-Philippe; Dunyach-Remy, Catherine

2017-01-01

Social bacterial interactions are considered essential in numerous infectious diseases, particularly in wounds. Foot ulcers are a common complication in diabetic patients and these ulcers become frequently infected. This infection is usually polymicrobial promoting cell-to-cell communications. Staphylococcus aureus is the most prevalent pathogen isolated. Its association with Helcococcus kunzii , commensal Gram-positive cocci, is frequently described. The aim of this study was to assess the impact of co-infection on virulence of both H. kunzii and S. aureus strains in a Caenorhabditis elegans model. To study the host response, qRT-PCRs targeting host defense genes were performed. We observed that H. kunzii strains harbored a very low (LT50: 5.7 days ± 0.4) or an absence of virulence (LT50: 6.9 days ± 0.5). In contrast, S. aureus strains (LT50: 2.9 days ± 0.4) were significantly more virulent than all H. kunzii ( P aureus strains were associated, H. kunzii significantly reduced the virulence of the S. aureus strain in nematodes (LT50 between 4.4 and 5.2 days; P aureus led to a strong induction of defense genes ( lys-5, sodh-1 , and cyp-37B1 ) while H. kunzii did not. No statistical difference of host response genes expression was observed when C. elegans were infected with either S. aureus alone or with S. aureus + H. kunzii . Moreover, two well-characterized virulence factors ( hla and agr ) present in S. aureus were down-regulated when S. aureus were co-infected with H. kunzii . This study showed that H. kunzii decreased the virulence of S. aureus without modifying directly the host defense response. Factor(s) produced by this bacterium modulating the staphylococci virulence must be investigated.

Staphylococcus aureus Transcriptome Architecture

DEFF Research Database (Denmark)

Mäder, Ulrike; Nicolas, Pierre; Depke, Maren

2016-01-01

Staphylococcus aureus is a major pathogen that colonizes about 20% of the human population. Intriguingly, this Gram-positive bacterium can survive and thrive under a wide range of different conditions, both inside and outside the human body. Here, we investigated the transcriptional adaptation of...

Construction of Stable Fluorescent Reporter Plasmids for Use in Staphylococcus aureus

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Michelle D. Rodriguez

2017-12-01

Full Text Available Here, the genes encoding three different fluorescent proteins were cloned into the stably maintained Staphylococcus aureus shuttle vector pKK30. The resulting plasmids were transformed into two S. aureus strains; SH1000 and RN4220. Stability assays illustrated that the three recombinant plasmids retained near 100% maintenance in vitro for 160 generations. S. aureus strain SH1000 expressing green fluorescent protein was then inoculated in an ovine model and in vivo stability for 6 days was demonstrated. In essence, these reporter plasmids represent a useful set of tools for dynamic imaging studies in S. aureus. These three reporter plasmids are available through BEI Resources.

Construction of Stable Fluorescent Reporter Plasmids for Use in Staphylococcus aureus.

Science.gov (United States)

Rodriguez, Michelle D; Paul, Zubin; Wood, Charles E; Rice, Kelly C; Triplett, Eric W

2017-01-01

Here, the genes encoding three different fluorescent proteins were cloned into the stably maintained Staphylococcus aureus shuttle vector pKK30. The resulting plasmids were transformed into two S. aureus strains; SH1000 and RN4220. Stability assays illustrated that the three recombinant plasmids retained near 100% maintenance in vitro for 160 generations. S. aureus strain SH1000 expressing green fluorescent protein was then inoculated in an ovine model and in vivo stability for 6 days was demonstrated. In essence, these reporter plasmids represent a useful set of tools for dynamic imaging studies in S. aureus . These three reporter plasmids are available through BEI Resources.

Antibiotic resistant Staphylococcus aureus in Abia State of Nigeria ...

African Journals Online (AJOL)

The S. aureus. isolates varied in their antibiotic susceptibility pattern when tested for their sensitivity to 16 antibiotics. Eighty percent of the isolates were resistant to more than one antimicrobial agent. All the isolates showed resistance to nalidixic acid and 100% sensitivity to rifampicin. Key words: Staphylococcus aureus, ...

Fascitis necrosante bilateral de diseminación hematógena por Staphylococcus Aureus: Caso pediátrico Necrotizing bilateral fasciitis of hematogenous dissemination, caused by Staphylococcus Aureus: Pediatric case

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J.R. Manzani Baldi

2011-06-01

Full Text Available Presentamos un caso clínico muy poco frecuente de fascitis con miositis y necrosis cutánea en tronco y muslos, de presentación bilateral y simétrica y de mecanismo hematógeno, en una niña de 4 años durante el desarrollo de un cuadro séptico de foco primario orofaringeo, que requirió internamiento en centro de terapia intensiva pediátrica (CTP. Optamos por una conducta quirúrgica agresiva y precoz, apoyada por medidas médicas de soporte vital y antibioticoterapia empírica hasta el momento del diagnóstico. El agente etiológico fue Staphylococcus aureus. El resultado tras varias intervenciones, fue a costa de secuelas estéticas importantes. El seguimiento de la paciente tras 6 años de evolución, no ha mostrado ningún otro episodio similar.We present a not very frequent clinical case of fasciitis with miositis and cutaneous necrosis in trunk and thighs, with bilateral and symmetrical presentation and haematogenous dissemination mechanism in a 4 years old girl during the development of sepsis with primary oropharingeal focus, that required to be interned in paediatric intensive care unit. It was necessary and aggressive an precocious surgical treatment, supported by vital life measures and empiric antibiotics, until the final germen diagnosis. The etiologic agent was Staphylococcus aureus. As a result, there were very important aesthetic sequels after several surgical procedures. After 6 years evolution, there wasn't any other similar episode.

Deficiencia de glucosa-6-fosfato deshidrogenasa en un paciente con síndrome de Down

OpenAIRE

Francisco R. Cammarata Scalisi; Harry Sánchez; Graciela Cammarata Scalisi; Nayra Cabral Alfonso; Osmoire Moreno; Miguel Alonzo Bastardo Ramos; Gustavo Gil

2012-01-01

El síndrome de Down, es una alteración genética que ocurre cuando un individuo exhibe todo o una parte específica adicional del cromosoma 21 y es la entidad más frecuentemente asociada a retardo mental. La deficiencia de glucosa-6-fosfato deshidrogenasa, es el defecto enzimático más común en humanos y presenta patrón de herencia ligado al cromosoma X recesivo. Se debe a la mutación del gen G6PD, el cual causa diversos fenotipos bioquímicos y clínicos. Reportamos un caso de lactante menor masc...

Concomitant genotyping revealed diverse spreading between methicillin-resistant Staphylococcus aureus and methicillin-susceptible Staphylococcus aureus in central Taiwan.

Science.gov (United States)

Ho, Cheng-Mao; Lin, Chien-Yu; Ho, Mao-Wang; Lin, Hsiao-Chuan; Peng, Ching-Tien; Lu, Jang-Jih

2016-06-01

Staphylococcus aureus is a versatile bacterium, which can lead to various infectious diseases. Various molecular typing methods are applied to the evolution and epidemiology surveys of S. aureus, mostly for methicillin-resistant S. aureus (MRSA). However, methicillin-susceptible S. aureus (MSSA) is still an important pathogen, but their molecular typing is evaluated infrequently. Pulsed-field gel electrophoresis (PFGE), spa typing, and detection of five virulent genes for 95 MRSA and 56 MSSA isolates (July-December 2008 and July 2008-December 2009, respectively) during an overlapping period were performed. More diversity was found in MSSA isolates (23 pulsotypes and 25 spa types, excluding 4 new-type and 1 nontypable isolates for spa typing) than in MRSA isolates (19 pulsotypes and 16 spa types, excluding 1 new-type and 1 nontypable isolates for spa typing). By spa typing, t002 (n = 30), t037 (n = 23), t437 (n = 21), t234 (n = 3), t1081 (n = 3), and t1094 (n = 3) were the six major MRSA clones. For MSSA isolates, t189 (n = 13), t437 (n = 4), t084 (n = 3), t213 (n = 3), t701 (n = 3), and t7200 (n = 3) were the six major types. Combining PFGE and spa typing, there were five combinations (pulsotype + spa type) that contained both MRSA and MSSA isolates (pulsotype 9-t437, pulsotype 15-t037, pulsotype 19-t002, pulsotype 21-t002, and pulsotype 28-t1081). For all 151 S. aureus or 95 MRSA isolates, the PFGE typing had more discrimination power, but spa typing had larger discrimination index for 56 MSSA isolates. In conclusion, there were different predominant MRSA and MSSA clones clinically. Continuing longitudinal tracking of molecular typing is necessary for elucidating the evolution of this important clinical pathogen. Copyright © 2014. Published by Elsevier B.V.

Immunological role of nasal staphylococcus aureus carriage in patients with persistent allergic rhinitis

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Mohamed Yousif Atia

2008-10-01

Full Text Available Nasal carriage of staphylococcus aureus (S.aureus exerts immunomodulatory effect in patients with atopic dermatitis and it may contribute to airway inflammation and allergic response in patients with allergic rhinitis. We Aim to investigate the frequency of nasal S.aureus carriage in patients with persistent allergic rhinitis and its possible influence on their symptoms and immune markers. We chosed 20 non smoker patients with house dust mite (HDM allergy causing allergic rhinitis and 20 non smoker healthy subjects matched for age and sex. For all subjects rhinoscopy was done, skin prick test, nasal culture for S.aureus, nasal interleukin 4,nasal total IgE, serum total IgE and serum specific IgE(SSIgE for HDM. Nasal S.aureus was detected in 16/20 patients (80% and 5/20 (25% in healthy subjects with highly significant statistical difference plt0.01. Correlation of nasal staph.aureus count and different systemic and local immune markers revealed highly significant positive correlation between nasal S.aureus count and serum total IgE (r = 0.78, plt0.01 and significant positive correlation with SSIgE (HDM (r = 0.53, plt0.05, nasal total IgE (r = 0.39, plt0.05 and nasal IL-4 (r = 0.55, plt0.05. Nasal staph.aureus actively modulated the immune reaction in persistent allergic rhinitis patients by promoting local IgE production, so we recommend early detection and treatment of S.aureus carriage in patients

Frequency of methicillin resistant Staphylococcus aureus in health care

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Somayeh Rahimi-Alang

2011-03-01

Full Text Available Background: Methicillin resistant Staphylococcus aureus (MRSA is one of the most important pathogen in hospitals. Healthcare personnel are the main source of nosocomial infections and identification and control of MRSA carriers can reduce incidence of infections. The aim of this study was to determine the prevalence of MRSA and their antibiotic susceptibility profile among healthcare workers in Gorgan.Materials and Method: 333 healthcare workers were participated in this cross-sectional study in 2009. Samples were taken with sterile cotton swabs from both anterior nares and hands. Swabs were plated immediately on to the mannitol salt agar. Suspected colonies were confirmed as S. aureus by Gram staining, catalase, coagulase and DNase tests. Minimum inhibition concentration by micro dilution broth method was used to determine methicillin resistant strains. Antimicrobial susceptibility to other antibiotics was performed according to NCCLS guidelines by disc diffusion method.Result: Frequency of S.aureus and MRSA carriers among healthcare workers was 24% and 3% respectively. The highest rate of S. aureus and MRSA carriers were observed in operating room staff. Resistance to penicillin was seen in 97.5% of isolates and all strains were sensitive to vancomycin.Conclusions: Frequency of S. aureus and MRSA in healthcare workers was median and rather low respectively. Continual monitoring and control of carriers can reduce distribution of this organism and their infections

Mode of action of Buddleja cordata verbascoside against Staphylococcus aureus.

Science.gov (United States)

Avila, J G; de Liverant, J G; Martínez, A; Martínez, G; Muñoz, J L; Arciniegas, A; Romo de Vivar, A

1999-07-01

We evaluate the mode of action of verbascoside obtained from Buddleja cordata against Staphylococcus aureus by killing kinetics and incorporation of precursors methods. Verbascoside induced lethal effect on S. aureus, by affecting protein synthesis and inhibiting leucine incorporation.

Virulence potential of Staphylococcus aureus isolates from Buruli ulcer patients.

Science.gov (United States)

Amissah, Nana Ama; Chlebowicz, Monika A; Ablordey, Anthony; Tetteh, Caitlin S; Prah, Isaac; van der Werf, Tjip S; Friedrich, Alex W; van Dijl, Jan Maarten; Stienstra, Ymkje; Rossen, John W

2017-06-01

Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients. Previously sequenced genomes of 21 S. aureus isolates from BU patients were screened for the presence of virulence genes. The results show that all S. aureus isolates harbored on their core genomes genes for known virulence factors like α-hemolysin, and the α- and β-phenol soluble modulins. Besides the core genome virulence genes, mobile genetic elements (MGEs), i.e. prophages, genomic islands, pathogenicity islands and a Staphylococcal cassette chromosome (SCC) were found to carry different combinations of virulence factors, among them genes that are known to encode factors that promote immune evasion, superantigens and Panton-Valentine Leucocidin. The present observations imply that the S. aureus isolates from BU patients harbor a diverse repertoire of virulence genes that may enhance bacterial survival and persistence in the wound environment and potentially contribute to delayed wound healing. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Occurrence and distribution of Staphylococcus aureus lineages among zoo animals

DEFF Research Database (Denmark)

Gongora, Carmen Espinosa; Chrobak, Dorota; Moodley, Arshnee

2012-01-01

The current knowledge of the occurrence and diversity of Staphylococcus aureus in animals is largely biased in favour MRSA and domestic animals. In order to generate novel information on the ecology and population structure of this bacterial species in the animal kingdom, we investigated...... the occurrence and genotypic diversity of S. aureus in a range of animal species kept at the Copenhagen Zoo. We sampled 146 animals belonging to 25 mammalian species and 21 reptiles belonging to six species. A total of 59 S. aureus isolates were found in 10 of the 25 mammalian species tested. All isolates were...... MSSA belonging to fourteen spa types, including three novel spa types. MLST revealed the occurrence of seven STs. The study of the ecology of commensal S. aureus in captive wild animals revealed that ST133 has a broader host range than previously thought....

Evaluation of Approaches to Monitor Staphylococcus aureus Virulence Factor Expression during Human Disease

OpenAIRE

Rozemeijer, Wouter; Fink, Pamela; Rojas, Eduardo; Jones, C. Hal; Pavliakova, Danka; Giardina, Peter; Murphy, Ellen; Liberator, Paul; Jiang, Qin; Girgenti, Douglas; Peters, Remco P. H.; Savelkoul, Paul H. M.; Jansen, Kathrin U.; Anderson, Annaliesa S.; Kluytmans, Jan

2015-01-01

Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag) vaccine comprising capsular polysaccharide (types 5 and 8) conjugates, clumping factor A (ClfA) and manganese transporter C (MntC) is under development. This study was designed to characterize S. aureus isolates recovered from infected patients and also to investigate approaches for examining expression of S. aureus vaccine candid...

Study of nosocomial isolates of Staphylococcus aureus with special reference to methicillin resistant S. aureus in a tertiary care hospital in Nepal.

Science.gov (United States)

Shrestha, B; Pokhrel, B; Mohapatra, T

2009-06-01

To find out the prevalence of Staphylococcus aureus nosocomial infection and methicillin resistant S. aureus (MRSA), clinical samples from nosocomially infected patients were processed by following standard methodology in microbiology laboratory, Tribhuvan University Teaching Hospital, Kathmandu, Nepal. Of 149 S. aureus isolates, skin infection isolates contributed a major part 72.5% making nosocomial infection by S. aureus most prevalent in skin infection followed by lower respiratory tract infection 11.41% and urinary tract infection 8.7%. Overall MRSA prevalence was 45.0%. MRSA prevalence was 42.6% in skin infection, 82.3% in lower respiratory tract infection and 30.8% in urinary tract infection. MRSA infection was found associated with lower respiratory tract infection only. Highest occurrence of nosocomial infection was observed in female surgical ward, surgical out patient department, orthopedic ward, male surgical ward and maternity ward. MRSA isolation was high from lower respiratory tract of patients admitted in intensive care unit, coronary care unit, Sub-acute intensive care unit, intermediate coronary care unit, neurology ward and post-operative ward. Whereas methicillin sensitive S. aureus (MSSA) occurrence was higher in patients admitted in orthopedic, Surgical out patient department, and female surgical ward. The occurrence of MRSA did not differ with age but MRSA was found associated with male patients and MSSA was associated with female patients. Since MRSA prevalence was high, regular surveillance of MRSA and nosocomial infections should be done and universal precautions to control nosocomial infections should be followed.

UJI ZONA HAMBAT EKSTRAK DAUN PUTRI MALU (Mimosa pudica TERHADAP BAKTERI Staphylococcus aureus DAN Methicillin-resistant Staphylococcus aureus (MRSA SECARA IN VITRO

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Nyoman Ririn Chandrika Sari

2015-04-01

Full Text Available Resistensi Staphylococcus aureus dan MRSA terhadap antibiotika spektrum luas mendorong berbagai penelitian untuk menemukan senyawa aktif yang sensitif dan efektif dalam menghambat pertumbuhan bakteri.Penelitian ini bertujuan untuk mengetahui efek penghambatan ekstrak daun putri malu (Mimosa pudica terhadap pertumbuhan bakteri Staphylococcus aureus dan MRSA.Penelitian terhadap aktivitas antimikrobial ekstrak daun putri malu dilakukan dengan metode agar difusi cakram dengan menggunakan metode Kirby-Bauer.Suspensi bakteri disesuaikan dengan standar kekeruhan Mc Farland 0.5. Biakan bakteri dalam cawan petri masing-masing diberikan 6 perlakuan, yaitu kontrol positif (amoxicillin atau vancomycin, kontrol negatif (alkohol, serta ekstrak daun putri malu dengan konsentrasi 25 mcg/ml, 50 mcg/ml, 75 mcg/ml dan 100 mcg/ml. Pertumbuhan Staphylococcus aureus dihambat secara signifikan oleh ekstrak daun putri malu, dengan efek inhibisi pada semua konsentrasi secara signifikan lebih baik dibandingkan dengan kontrol positif (p<0.05. Zona inhibisi Staphylococcus aureus pada konsentrasi 25 mcg/ml adalah 28.86 mm dan telah memenuhi kriteria sebagai antimikrobial sensitif berdasarkan Clinical and Laboratory Standard Institute (CLSI. Inhibisi pertumbuhan MRSA secara signifikan terjadi pada semua konsentrasi ekstrak daun putri malu dibandingkan dengan kontrol negatif (p=0.00. Zona inhibisi terbesar ditemukan pada konsentrasi 100 mcg/ml dengan diameter sebesar 14.16 mm dan memiliki efek antimikrobial sebanding dengan vancomycin dalam menghambat pertumbuhan MRSA (p=0.186. Hasil uji agar difusi cakram menunjukkan bahwa senyawa aktif dalam ekstrak daun putri malu memiliki aktivitas antimikrobial yang tinggi terhadap Staphylococcus aureus dan MRSA secara in vitro.

PRODUKSI IGY SPESIFIK STAPHYLOCOCCUS AUREUS DARI ISOLAT ASAL KASUS STAPHYLOCOCCOSIS PADA KELINCI

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Triwardhani Cahyaningsih

2017-04-01

Full Text Available This experiment aims to produce immunoglobulin Y (Ig-Y Staphylococcus aureus isolates origin staphylococcosis case in rabbits. Vaccination is done several times using Staphylococcus aureus active in 109 cfu/ml. Injecting the chicken is done four weeks in a row, the first week is done by intravenous injection of S. aureus antigens, the second week of the injection sub cutan S. aureus emulsified with Freund's complete adjuvant, followed by the third and fourth week of the injection of S. aureus antigen emulsified with incomplete Freund's adjuvant. Egg samples were taken after four weeks of the last injection for identification, purification, and determination of specific IgY against S. aureus in egg yolk. IgY specificity qualitatively tests performed by the AGP test (To Gel Precipitation. IgY extraction is done using PEG - Ammonium sulfate, purified IgY concentration calculated by the method of Bradford. The results showed that IgY began to be detected in egg yolk at week six after immunization, with the average levels of IgY is 1.7 mg/ml.

Study on biofilm-forming properties of clinical isolates of Staphylococcus aureus.

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Taj, Yasmeen; Essa, Farhan; Aziz, Faisal; Kazmi, Shahana Urooj

2012-05-14

The purpose of this study was to observe the formation of biofilm, an important virulence factor, by isolates of Staphylococcus aureus (S. aureus) in Pakistan by different conventional methods and through electron microscopy. We screened 115 strains of S. aureus isolated from different clinical specimens by tube method (TM), air-liquid interface coverslip assay method, Congo red agar (CRA) method, and scanning electron microscopy (SEM). Out of 115 S. aureus isolates, 63 (54.78%) showed biofilm formation by tube method. Biofilm forming bacteria were further categorized as high producers (n = 23, 20%) and moderate producers (n = 40, 34.78%). TM coordinated well with the coverslip assay for strong biofilm-producing strains in 19 (16.5%) isolates. By coverslip method, weak producers were difficult to differentiate from biofilm negative isolates. Screening on CRA showed biofilm formation only in four (3.47%) strains. Scanning electron micrographs showed the biofilm-forming strains of S. aureus arranged in a matrix on the propylene surface and correlated well with the TM. Biofilm production is a marker of virulence for clinically relevant staphylococcal infections. It can be studied by various methods but screening on CRA is not recommended for investigation of biofilm formation in Staphylococcus aureus. Electron micrograph images correlate well with the biofilm production as observed by TM.

Quality of the blood pressure phenotype in the GEnotipo, Fenotipo y Ambiente de la hipertensión arterial en UruguaY (GEFA-HT-UY) study.

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Luzardo, Leonella; Sottolano, Mariana; Lujambio, Inés; Robaina, Sebastián; Thijs, Lutgarde; da Rosa, Alicia; Krul, Nadia; Carusso, Florencia; Ríos, Ana C; Olascoaga, Alicia; Noboa, Oscar; Staessen, Jan A; Boggia, José

2014-12-01

In the ongoing GEnotipo, Fenotipo y Ambiente de la HiperTensión Arterial en UruguaY (GEFA-HT-UY) study, we applied standardized epidemiological methods to determine complex phenotypes including blood pressure (BP). In this report, we present the quality control of the conventionally measured BP. Three trained observers measured BP five times consecutively in the seated position at each of two home visits and one clinic visit according to the guidelines of the European Society of Hypertension. On 1 December 2013, 4379 single BP readings in 170 participants were available for analysis. Fewer BP readings than the five planned per contact occurred only at one home visit. Among observers, the frequency of identical consecutive readings for systolic or diastolic BP varied from 0 to 4.2%. The occurrence of odd readings ranged from 0.1 to 0.6%. Only 21.6% of the systolic and diastolic BP readings ended on zero (expected 20%). At home visits, there was a progressive decline in BP from the first to the fifth reading. The average of the five BP readings also decreased from the first to the second home visit (-5.63/-2.34 mmHg). Our study highlighted the necessity to implement a stringent quality control of the conventionally measured BP. The procedures set up in the GEFA-HT-UY study are resulting in a well-defined BP phenotype, which is consistent with that in other population studies.

Occurrence and antimicrobial resistance of Staphylococcus aureus in bulk tank milk and milk filters

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Kateřina Bogdanovičová

2014-02-01

Full Text Available This work is focused on the monitoring of Staphylococcus aureus prevalence in raw milk and milk filters, its antibiotic resistance and detection of methicillin resistant Staphylococcus aureus (MRSA. Samples of raw cow´s milk and milk filters were collected in the period from 2012 till 2014, from 50 dairy farms in the Czech Republic. The total of 261 samples (164 samples of raw milk and 97 milk filters were cultivated on Baird-Parker agar. Both the typical and atypical colonies were examined by plasmacoagulase test and PCR method was used for detection of species specific fragment SA442 and mecA gene. Standard disk diffusion method was used to determinate resistance to antimicrobial agents. The bacterium Staphylococcus aureus was detected on 25 farms (50%. The antimicrobial resistance showed differences between the farms. Total of 58 samples were positive for Staphylococcus aureus, of which were 37 (14.2% isolated from raw milk samples and 21 (8.1% from milk filters. From these samples we isolated 62 Staphylococcus aureus strains, 41 isolates bacteria S. aureus from raw milk (66.1% and 21 isolates S. aureus from milk filters (33.9%. The presence of antibiotic resistance in Staphylococcus aureus isolates was low, most of them were resistant to amoxicilin. According to the results obtained by the PCR method for the methicillin - resistant S. aureus (MRSA, the mecA gene was present in 6 strains (9.7%, 4 isolates obtained from milk samples (6.5% and 2 isolates from milk filters (3.2%.  These isolates can be considered as a possible source of resistance genes, which can be spread through the food chain. Nowadays, a globally unfavourable increasing trend of prevalence of methicillin resistant staphylococci strains especially Staphylococcus aureus is being observed worldwide. The improper hygiene and poor farm management practices contributed to the presence of S. aureus in the milk. This may have contributed to the high level of S. aureus isolated

Staphylococcus aureus ST398 from slaughter pigs in northeast China

NARCIS (Netherlands)

Yan, Xiaomei; Yu, Xiaojie; Tao, Xiaoxia; Zhang, Jianfeng; Zhang, Binghua; Dong, Rui; Xue, Chengyu; Grundmann, Hajo; Zhang, Jianzhong

To describe the prevalence and population structure of Staphylococcus aureus bacteria that colonize pigs at slaughterhouses in northeastern China, nose swabs were collected from pigs in two slaughterhouses in Harbin, Heilongjiang Province, China in 2009.S. aureus isolates were characterized by

Calcium and Magnesium Ions Are Membrane-Active against Stationary-Phase Staphylococcus aureus with High Specificity

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Xie, Yuntao; Yang, Lihua

2016-02-01

Staphylococcus aureus (S. aureus) is notorious for its ability to acquire antibiotic-resistance, and antibiotic-resistant S. aureus has become a wide-spread cause of high mortality rate. Novel antimicrobials capable of eradicating S. aureus cells including antibiotic-resistant ones are thus highly desired. Membrane-active bactericides and species-specific antimicrobials are two promising sources of novel anti-infective agents for fighting against bacterial antibiotic-resistance. We herein show that Ca2+ and Mg2+, two alkaline-earth-metal ions physiologically essential for diverse living organisms, both disrupt model S. aureus membranes and kill stationary-phase S. aureus cells, indicative of membrane-activity. In contrast to S. aureus, Escherichia coli and Bacillus subtilis exhibit unaffected survival after similar treatment with these two cations, indicative of species-specific activity against S. aureus. Moreover, neither Ca2+ nor Mg2+ lyses mouse red blood cells, indicative of hemo-compatibility. This works suggests that Ca2+ and Mg2+ may have implications in targeted eradication of S. aureus pathogen including the antibiotic-resistant ones.

Sepse por Staphylococus aureus resistente à meticilina adquirida na comunidade no sul do Brasil Sepsis due to community-acquired methicillin-resistant Staphylococcus aureus in southern Brazil

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Luciane Cristina Gelatti

2009-08-01

Full Text Available Staphylococcus aureus resistente à meticilina foi inicialmente descrito como um típico microrganismo adquirido em infecções nosocomiais. No entanto, nos últimos anos Staphylococcus aureus resistente à meticilina adquirido na comunidade é causa de infecções de pele e tecidos moles, mas infecções graves como pneumonia e sepse podem ocorrer. Este relato descreve um caso de sepse em criança, complicado com pneumonia secundária a lesão em partes moles por Staphylococcus aureus resistente à meticilina adquirido na comunidade no Sul do Brasil. O paciente foi atendido em Unidade de Emergência com história de ferimento provocado por trauma em membro inferior que evoluiu para celulite, pneumonia e sepse.Methicillin-resistant Staphylococcus aureus was initially described as a typical microorganism acquired in nosocomial infections. However, over recent years, community-acquired methicillin-resistant Staphylococcus aureus has been a cause of skin and soft-tissue infections. Serious infections such as pneumonia and sepsis can also occur. This report describes a case of sepsis in a child that was complicated by pneumonia secondary to soft tissue lesions that were due to community-acquired methicillin-resistant Staphylococcus aureus in southern Brazil. The patient was attended at the Emergency Unit with a history of injury caused by lower-limb trauma that evolved to cellulitis, pneumonia and sepsis.

Health and economic burden of post-partum Staphylococcus aureus breast abscess.

Science.gov (United States)

Branch-Elliman, Westyn; Lee, Grace M; Golen, Toni H; Gold, Howard S; Baldini, Linda M; Wright, Sharon B

2013-01-01

To determine the health and economic burdens of post-partum Staphylococcus aureus breast abscess. We conducted a matched cohort study (N = 216) in a population of pregnant women (N = 32,770) who delivered at our center during the study period from 10/1/03-9/30/10. Data were extracted from hospital databases, or via chart review if unavailable electronically. We compared cases of S. aureus breast abscess to controls matched by delivery date to compare health services utilization and mean attributable medical costs in 2012 United States dollars using Medicare and hospital-based estimates. We also evaluated whether resource utilization and health care costs differed between cases with methicillin-resistant and -susceptible S. aureus isolates. Fifty-four cases of culture-confirmed post-partum S. aureus breast abscess were identified. Breastfeeding cessation (41%), milk fistula (11.1%) and hospital readmission (50%) occurred frequently among case patients. Breast abscess case patients had high rates of health services utilization compared to controls, including high rates of imaging and drainage procedures. The mean attributable cost of post-partum S. aureus breast abscess ranged from $2,340-$4,012, depending on the methods and data sources used. Mean attributable costs were not significantly higher among methicillin-resistant vs. -susceptible S. aureus cases. Post-partum S. aureus breast abscess is associated with worse health and economic outcomes for women and their infants, including high rates of breastfeeding cessation. Future study is needed to determine the optimal treatment and prevention of these infections.

Health and economic burden of post-partum Staphylococcus aureus breast abscess.

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Westyn Branch-Elliman

Full Text Available To determine the health and economic burdens of post-partum Staphylococcus aureus breast abscess.We conducted a matched cohort study (N = 216 in a population of pregnant women (N = 32,770 who delivered at our center during the study period from 10/1/03-9/30/10. Data were extracted from hospital databases, or via chart review if unavailable electronically. We compared cases of S. aureus breast abscess to controls matched by delivery date to compare health services utilization and mean attributable medical costs in 2012 United States dollars using Medicare and hospital-based estimates. We also evaluated whether resource utilization and health care costs differed between cases with methicillin-resistant and -susceptible S. aureus isolates.Fifty-four cases of culture-confirmed post-partum S. aureus breast abscess were identified. Breastfeeding cessation (41%, milk fistula (11.1% and hospital readmission (50% occurred frequently among case patients. Breast abscess case patients had high rates of health services utilization compared to controls, including high rates of imaging and drainage procedures. The mean attributable cost of post-partum S. aureus breast abscess ranged from $2,340-$4,012, depending on the methods and data sources used. Mean attributable costs were not significantly higher among methicillin-resistant vs. -susceptible S. aureus cases.Post-partum S. aureus breast abscess is associated with worse health and economic outcomes for women and their infants, including high rates of breastfeeding cessation. Future study is needed to determine the optimal treatment and prevention of these infections.

Cambios a lo largo del tiempo en la distribución de los complejos de clones dominantes de Staphylococcus aureus resistente a la meticilina en Medellín, Colombia

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Ana M. Ocampo

2014-04-01

Full Text Available Introducción. Parte del éxito de Staphylococcus aureus resistente a la meticilina (SARM como patógeno se debe a la rápida diseminación de linajes pandémicos con perfiles variables de virulencia y sensibilidad antimicrobiana. En Colombia se han identificado clones asociados al hospital como el pediátrico (CC5-ST5-SCCmecIV, el brasilero (CC8-ST239-SCCmecIII y el chileno/cordobés (CC5-ST5-SCCmecI. Asimismo, se describió el USA300 (CC8-ST8-SCCmecIV, tradicionalmente asociado a la comunidad, causante de infecciones hospitalarias. Objetivo. Describir el comportamiento en el tiempo de los clones de SARM provenientes de un hospital universitario de Medellín en aislamientos recolectados con una década de diferencia. Materiales y métodos. Se analizaron 398 aislamientos de SARM, 67 recolectados en 1994 y 331 recolectados entre 2008 y 2010. La identificación y la sensibilidad a la meticilina se confirmaron mediante los genes nuc y mecA. La caracterización molecular incluyó la tipificación de spa, SCCmec, la electroforesis en gel de campo pulsado (Pulsed Field Gel Electrophoresis, PFGE, y la tipificación por secuenciación de locus múltiples (Multilocus Sequence Typing, MLST. Resultados. Al analizar los aislamientos de SARM de 1994 se encontró que pertenecían a un único linaje, el CC5-SCCmecIV, mientras que los aislamientos de 2008 a 2010 presentaron dos linajes dominantes: el CC8-SCCmecIVc, con cepas de los tipos spa t008 y t1610, estrechamente relacionadas con el clon USA 300, y el CC5-SCCmecI, con las de tipo spa t149, relacionadas con el clon chileno; no se detectaron cepas del linaje encontrado en 1994. Conclusiones. En este estudio se demuestra una dinámica en el tiempo de las cepas de S. aureus, y se señala la importancia de la vigilancia local y la difusión de los resultados, sobre todo en países como el nuestro, donde SARM es prevalente y la comprensión de su epidemiología es limitada.

Fresh garlic extract inhibits Staphylococcus aureus biofilm formation under chemopreventive and chemotherapeutic conditions

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Panan Ratthawongjirakul

2016-08-01

Full Text Available Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA are the leading aetiological pathogens of nosocomial infections worldwide. These bacteria form biofilms on both biotic and abiotic surfaces causing biofilm-associated infections. Within the biofilm, these bacteria might develop persistent and antimicrobial resistant characteristics resulting in chronic infections and treatment failures. Garlic exhibits broad pharmaceutical properties and inhibitory activities against S. aureus. We investigated the effects of aqueous fresh garlic extract on biofilm formation in S. aureus ATCC25923 and MRSA strains under chemopreventive and chemotherapeutic conditions. The viable bacteria and biofilm levels were quantified through colony count and crystal violet staining, respectively. The use of fresh garlic extract under both conditions significantly inhibited biofilm formation in S. aureus strains ATCC25923 and MRSA. Garlic could be developed as either a prophylactic or therapeutic agent to manage S. aureus biofilm-associated infections.

Evaluation of approaches to monitor Staphylococcus aureus virulence factor expression during human disease.

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Wouter Rozemeijer

Full Text Available Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag vaccine comprising capsular polysaccharide (types 5 and 8 conjugates, clumping factor A (ClfA and manganese transporter C (MntC is under development. This study was designed to characterize S. aureus isolates recovered from infected patients and also to investigate approaches for examining expression of S. aureus vaccine candidates and the host response during human infection. Confirmation of antigen expression in different disease states is important to support the inclusion of these antigens in a prophylactic vaccine. Hospitalized patients with diagnosed S. aureus wound (27 or bloodstream (24 infections were enrolled. Invasive and nasal carriage S. aureus isolates were recovered and characterized for genotypic diversity. S. aureus antigen expression was evaluated directly by real-time, quantitative, reverse-transcriptase PCR (qRT-PCR analysis and indirectly by serology using a competitive Luminex immunoassay. Study isolates were genotypically diverse and all had the genes encoding the antigens present in the SA4Ag vaccine. S. aureus nasal carriage was detected in 55% of patients, and in those subjects 64% of the carriage isolates matched the invasive strain. In swab samples with detectable S. aureus triosephosphate isomerase housekeeping gene expression, RNA transcripts encoding the S. aureus virulence factors ClfA, MntC, and capsule polysaccharide were detected by qRT-PCR. Antigen expression was indirectly confirmed by increases in antibody titer during the course of infection from acute to convalescent phase. Demonstration of bacterial transcript expression together with immunological response to the SA4Ag antigens in a clinically relevant patient population provides support for inclusion of these antigens in a prophylactic vaccine.

Evaluation of approaches to monitor Staphylococcus aureus virulence factor expression during human disease.

Science.gov (United States)

Rozemeijer, Wouter; Fink, Pamela; Rojas, Eduardo; Jones, C Hal; Pavliakova, Danka; Giardina, Peter; Murphy, Ellen; Liberator, Paul; Jiang, Qin; Girgenti, Douglas; Peters, Remco P H; Savelkoul, Paul H M; Jansen, Kathrin U; Anderson, Annaliesa S; Kluytmans, Jan

2015-01-01

Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag) vaccine comprising capsular polysaccharide (types 5 and 8) conjugates, clumping factor A (ClfA) and manganese transporter C (MntC) is under development. This study was designed to characterize S. aureus isolates recovered from infected patients and also to investigate approaches for examining expression of S. aureus vaccine candidates and the host response during human infection. Confirmation of antigen expression in different disease states is important to support the inclusion of these antigens in a prophylactic vaccine. Hospitalized patients with diagnosed S. aureus wound (27) or bloodstream (24) infections were enrolled. Invasive and nasal carriage S. aureus isolates were recovered and characterized for genotypic diversity. S. aureus antigen expression was evaluated directly by real-time, quantitative, reverse-transcriptase PCR (qRT-PCR) analysis and indirectly by serology using a competitive Luminex immunoassay. Study isolates were genotypically diverse and all had the genes encoding the antigens present in the SA4Ag vaccine. S. aureus nasal carriage was detected in 55% of patients, and in those subjects 64% of the carriage isolates matched the invasive strain. In swab samples with detectable S. aureus triosephosphate isomerase housekeeping gene expression, RNA transcripts encoding the S. aureus virulence factors ClfA, MntC, and capsule polysaccharide were detected by qRT-PCR. Antigen expression was indirectly confirmed by increases in antibody titer during the course of infection from acute to convalescent phase. Demonstration of bacterial transcript expression together with immunological response to the SA4Ag antigens in a clinically relevant patient population provides support for inclusion of these antigens in a prophylactic vaccine.

Staphylococcus aureus in Some Brazilian Dairy Industries: Changes of Contamination and Diversity

DEFF Research Database (Denmark)

Dittmann, Karen Kiesbye; Chaul, Luiza T.; Lee, Sarah H. I.

2017-01-01

Staphylococcus aureus, a major food-poisoning pathogen, is a common contaminant in dairy industries worldwide, including in Brazil. We determined the occurrence of S. aureus in five dairies in Brazil over 8 months. Of 421 samples, 31 (7.4%) were positive for S. aureus and prevalence varied from 0.......8% of strains being sensitive to all antibiotic classes and no Methicillin-resistant S. aureus (MRSA) strains were found. The enterotoxin-encoding genes involved in food-poisoning, e.g., sea, sed, see, and seg were targeted by PCR. The two toxin-encoding genes, sed and see, were not detected. Only three strains...... contamination....

Comparación de tres métodos indirectos para estimar el crecimiento de la tilapia Oreochromis aureus (Perciformes: Cichlidae en un lago tropical de México

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Andrés Arellano-Torres

2013-09-01

Full Text Available Una de las pesquerías de aguas continentales más importantes en México es la pesca de la tilapia Oreochromis aureus. Con base en el análisis de frecuencia de tallas mediante ELEFAN, SLCA y PROJMAT se estimó el crecimiento en la tilapia en el lago de Chapala, Jalisco, para lo cual se utilizaron 1 973 individuos que fueron recolectados de la captura comercial de enero a diciembre 2010. Se cuantificó la variabilidad de los estimadores y el efecto de las muestras mensuales a través de la técnica de remuestreo jackknife. Los parámetros de crecimiento de L∞ y K se unificaron para efectos comparativos mediante el índice de crecimiento estándar (f’. Con los tres métodos utilizados se estimaron valores de los parámetros de crecimiento que se encuentran dentro del rango reportado en la literatura. La aplicación de jackknife mostró que ELEFAN estimó los mejores resultados, con los valores más bajos en el error porcentual y coeficiente de variación para L∞, en tanto PROJMAT presentó los valores más bajos en los estimadores de precisión para K, la cual fue muy similar a la de ELEFAN. Los intervalos del índice comparativo de crecimiento f’ fueron muy similares a los reportados para la especie en diferentes embalses. Se sugiere el uso de ELEFAN en lugar de SLCA, debido a su precisión para estimar los parámetros de crecimiento de Oreochromis aureus.

Heme Recognition By a Staphylococcus Aureus IsdE

Energy Technology Data Exchange (ETDEWEB)

Grigg, J.C.; Vermeiren, C.L.; Heinrichs, D.E.; Murphy, M.E.P.

2009-06-03

Staphylococcus aureus is a Gram-positive bacterial pathogen and a leading cause of hospital acquired infections. Because the free iron concentration in the human body is too low to support growth, S. aureus must acquire iron from host sources. Heme iron is the most prevalent iron reservoir in the human body and a predominant source of iron for S. aureus. The iron-regulated surface determinant (Isd) system removes heme from host heme proteins and transfers it to IsdE, the cognate substrate-binding lipoprotein of an ATP-binding cassette transporter, for import and subsequent degradation. Herein, we report the crystal structure of the soluble portion of the IsdE lipoprotein in complex with heme. The structure reveals a bi-lobed topology formed by an N- and C-terminal domain bridged by a single {alpha}-helix. The structure places IsdE as a member of the helical backbone metal receptor superfamily. A six-coordinate heme molecule is bound in the groove established at the domain interface, and the heme iron is coordinated in a novel fashion for heme transporters by Met{sup 78} and His{sup 229}. Both heme propionate groups are secured by H-bonds to IsdE main chain and side chain groups. Of these residues, His{sup 299} is essential for IsdE-mediated heme uptake by S. aureus when growth on heme as a sole iron source is measured. Multiple sequence alignments of homologues from several other Gram-positive bacteria, including the human pathogens pyogenes, Bacillus anthracis, and Listeria monocytogenes, suggest that these other systems function equivalently to S. aureus IsdE with respect to heme binding and transport.

Characterization of a mouse-adapted Staphylococcus aureus strain.

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Silva Holtfreter

Full Text Available More effective antibiotics and a protective vaccine are desperately needed to combat the 'superbug' Staphylococcus aureus. While in vivo pathogenicity studies routinely involve infection of mice with human S. aureus isolates, recent genetic studies have demonstrated that S. aureus lineages are largely host-specific. The use of such animal-adapted S. aureus strains may therefore be a promising approach for developing more clinically relevant animal infection models. We have isolated a mouse-adapted S. aureus strain (JSNZ which caused a severe outbreak of preputial gland abscesses among male C57BL/6J mice. We aimed to extensively characterize this strain on a genomic level and determine its virulence potential in murine colonization and infection models. JSNZ belongs to the MLST type ST88, rare among human isolates, and lacks an hlb-converting phage encoding human-specific immune evasion factors. Naive mice were found to be more susceptible to nasal and gastrointestinal colonization with JSNZ than with the human-derived Newman strain. Furthermore, naïve mice required antibiotic pre-treatment to become colonized with Newman. In contrast, JSNZ was able to colonize mice in the absence of antibiotic treatment suggesting that this strain can compete with the natural flora for space and nutrients. In a renal abscess model, JSNZ caused more severe disease than Newman with greater weight loss and bacterial burden. In contrast to most other clinical isolates, JSNZ can also be readily genetically modified by phage transduction and electroporation. In conclusion, the mouse-adapted strain JSNZ may represent a valuable tool for studying aspects of mucosal colonization and for screening novel vaccines and therapies directed at preventing colonization.

Incidence, trends and demographics of Staphylococcus aureus infections in Auckland, New Zealand, 2001–2011

Science.gov (United States)

2013-01-01

Background New Zealand has a higher incidence of Staphylococcus aureus disease than other developed countries, with significant sociodemographic variation in incidence rates. In contrast to North America, the majority of disease is due to methicillin-susceptible S. aureus (MSSA), although relatively little is known about the comparative demographics of MSSA and methicillin-resistant S. aureus (MRSA) infections in New Zealand. Methods Our objectives were to describe the trends, incidence and patient demographics of all S. aureus infections in patients presenting to our institution between 2001 and 2011, and compare the epidemiology of MSSA and MRSA infections. We identified all patients with S. aureus infections over the study period. A unique S. aureus infection was defined as the first positive S. aureus culture taken from the same patient within a thirty-day period. Standard definitions were used to classify episodes into community- or healthcare-associated S. aureus infection. Results There were 16,249 S. aureus infections over the study period. The incidence increased significantly over the study period from 360 to 412 per 100,000 population (P New Zealand. The significant increase in community-associated S. aureus infections is of public health importance. Future studies should investigate the reasons underlying this concerning trend. PMID:24299298

Detection and identification of Staphylococcus aureus in raw milk by ...

African Journals Online (AJOL)

Staphylococcus aureus causes foodborne diseases if consumed in contaminated milk products. Rapid detection and characterization of foodborne pathogen S. aureus is crucial for epidemiological investigations and food safety surveillance. It is still a challenge to detect and identify bacterial pathogens quickly and ...

Staphylococcus aureus biofilms: recent developments in biofilm dispersal.

Science.gov (United States)

Lister, Jessica L; Horswill, Alexander R

2014-01-01

Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.

Reversible antibiotic tolerance induced in Staphylococcus aureus by concurrent drug exposure

DEFF Research Database (Denmark)

Haaber, Jakob Krause; Friberg, Cathrine; McCreary, Mark

2015-01-01

UNLABELLED: Resistance of Staphylococcus aureus to beta-lactam antibiotics has led to increasing use of the glycopeptide antibiotic vancomycin as a life-saving treatment for major S. aureus infections. Coinfection by an unrelated bacterial species may necessitate concurrent treatment with a second...... antibiotic that targets the coinfecting pathogen. While investigating factors that affect bacterial antibiotic sensitivity, we discovered that susceptibility of S. aureus to vancomycin is reduced by concurrent exposure to colistin, a cationic peptide antimicrobial employed to treat infections by Gram......-negative pathogens. We show that colistin-induced vancomycin tolerance persists only as long as the inducer is present and is accompanied by gene expression changes similar to those resulting from mutations that produce stably inherited reduction of vancomycin sensitivity (vancomycin-intermediate S. aureus [VISA...

Bacteriocins of Non-aureus Staphylococci Isolated from Bovine Milk.

Science.gov (United States)

Carson, Domonique A; Barkema, Herman W; Naushad, Sohail; De Buck, Jeroen

2017-09-01

Non- aureus staphylococci (NAS), the bacteria most commonly isolated from the bovine udder, potentially protect the udder against infection by major mastitis pathogens due to bacteriocin production. In this study, we determined the inhibitory capability of 441 bovine NAS isolates (comprising 26 species) against bovine Staphylococcus aureus Furthermore, inhibiting isolates were tested against a human methicillin-resistant S. aureus (MRSA) isolate using a cross-streaking method. We determined the presence of bacteriocin clusters in NAS whole genomes using genome mining tools, BLAST, and comparison of genomes of closely related inhibiting and noninhibiting isolates and determined the genetic organization of any identified bacteriocin biosynthetic gene clusters. Forty isolates from 9 species ( S. capitis , S. chromogenes , S. epidermidis , S. pasteuri , S. saprophyticus , S. sciuri , S. simulans , S. warneri , and S. xylosus ) inhibited growth of S. aureus in vitro , 23 isolates of which, from S. capitis , S. chromogenes , S. epidermidis , S. pasteuri , S. simulans , and S. xylosus , also inhibited MRSA. One hundred five putative bacteriocin gene clusters encompassing 6 different classes (lanthipeptides, sactipeptides, lasso peptides, class IIa, class IIc, and class IId) in 95 whole genomes from 16 species were identified. A total of 25 novel bacteriocin precursors were described. In conclusion, NAS from bovine mammary glands are a source of potential bacteriocins, with >21% being possible producers, representing potential for future characterization and prospective clinical applications. IMPORTANCE Mastitis (particularly infections caused by Staphylococcus aureus ) costs Canadian dairy producers $400 million/year and is the leading cause of antibiotic use on dairy farms. With increasing antibiotic resistance and regulations regarding use, there is impetus to explore bacteriocins (bacterially produced antimicrobial peptides) for treatment and prevention of bacterial

The modular structure of the floral phenotype in Mimulus luteus var. luteus (Phrymaceae Estructura modular del fenotipo floral en Mimulus luteus var. luteus (Phrymaceae

Directory of Open Access Journals (Sweden)

GASTÓN CARVALLO

2005-12-01

Full Text Available Most studies of multivariate evolution on the floral phenotype assume that traits evolve independently one from each other, ignoring the modular structure that results from genetic correlations or developmental constraints. In this paper we describe the interdependence of nine floral traits in the herb Mimulus luteus var. luteus (Phrymaceae, as an attempt to characterize functional modules on which natural selection can potentially act upon. Using edge exclusion deviance analysis, we detected four modules: (a an attractiveness module, (b a stigma behavior module, (c a stigma surface module, and (d a herkogamy module. Consequences of these findings for future studies of natural selection in this species are discussedLa mayor parte de los estudios de evolución multivariada sobre el fenotipo floral suponen que los rasgos evolucionan independientemente unos de otros, ignorando la estructura modular que resulta de correlaciones genéticas o restricciones impuestas por el desarrollo. En este trabajo describimos la interdependencia de nueve rasgos florales en Mimulus luteus var. luteus (Phrymaceae, en un intento por caracterizar los módulos funcionales sobre los cuales la selección natural pudiera eventualmente actuar. Mediante análisis de desviación límite-excluyente detectamos cuatro módulos: (a un módulo de atractividad floral, (b un módulo de comportamiento estigmático, (c un módulo de superficie estigmática, y (d un módulo de hercogamia. Se discuten las consecuencias de estos hallazgos para futuros estudios de selección natural en esta especie

Frecuencia de los grupos sanguíneos A1, A2, Aint, B y O en individuos normales

OpenAIRE

García Rosasco, Marcela; Lippi, Samanta; Valverde, Juana

2001-01-01

Se definen como A intermedio (Aint) los hematíes que comparten caracteres con A1 y A2. Existen diferencias cualitativas y cuantitativas en los epitopes A. Los hematíes A1 son aglutinados por la lectina de Dolichus biflorus (anti-A1), los A2 por la lectina de Ulex europaeus (anti-H), en tanto los hematíes Aint, son variablemente aglutinados por ambas de manera inesperada. El objetivo del presente trabajo fue determinar la frecuencia de fenotipos A1, Aint, A2, B y O en individuos normales de la...

Virulence potential of Staphylococcus aureus isolates from Buruli ulcer patients

NARCIS (Netherlands)

Amissah, Nana Ama; Chlebowicz, Monika A.; Ablordey, Anthony; Tetteh, Caitlin S.; Prah, Isaac; van der Werf, Tjip S.; Friedrich, Alex W.; van Dijl, Jan Maarten; Stienstra, Ymkje; Rossen, John W.

Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients.

Cemaran Staphylococcus aureus dan Pseudomonas aerogenosa Pada Stetoskop dirumah Sakit

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leka lutpiatina

2017-10-01

The result of the research was found contamination of Staphylococcus aureus and Pseudomonas aerogenosa on steteskop. The site home condition of the research data was 66.7% cleaned daily, the storage method was placed on the table 70% and the duration of using the set home more than 1 year as much as 70%. The conclusion of stethoscope at Banjarbaru Hospital was contaminated with Staphylococcus aureus by 70% and Pseudomonas aerogenosa by 17%. The suggestion of research can be continued by knowing the existence of Staphylococcus aureus resistant antibiotic and Pseudomonas aerogenous antibiotic resistant at steteskop at Hospital.

Valoración clínica, psicológica y de laboratorio a niños con hiperfenilalaninemia benigna al nacimiento

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Enna Gutiérrez García

2002-12-01

Full Text Available Las hiperfenilalaninemias, alteraciones en el metabolismo de la fenilalanina, poseen heterogeneidad genética, clínica y bioquímica, con fenilalanina en plasma, mayor de 120 µmol/L (2 mg/dL. La benigna tiene valores entre 240 y 600 µmol/L (4 a 10 mg/dL con mayor actividad enzimática y no requiere tratamiento dietético. Se realizó una valoración clínica y de laboratorio a 32 niños con esta alteración al nacimiento entre 1989 y 1999, para conocer variaciones en las concentraciones séricas en el tiempo, presentación de algún síntoma o signo clínico de la enfermedad y el coeficiente de inteligencia de estos. Los 32 niños estudiados presentaron disminución de niveles del aminoácido, con respecto al nacimiento, entre 90 y 287 µmol/L (1, 5 mg/dL a 5, 52 mg/dL. La mayoría no mostró síntomas o signos clínicos de fenilcetonuria. El coeficiente de inteligencia promedio fue de 100,6 puntos. Se recomienda el estudio a todos los niños con esta alteración en Cuba y realizar estudios de mutaciones para demostrar la heterogeneidad alélica que explicara la expresividad variable en el fenotipo bioquímico y clínico en estos niños.Hyperphenylalaninemias, which are disorders in the metabolism of phenylalanine, show genetic, clinical and biochemical heterogeneity, with phenylalanine in plasma over 120 µmol/L (2 mg/dL. Benign hyperphenylalaninemia has values from 240 to 600 µmol/L (4 a 10 mg/dL with higher enzymatic activity and does not require diet therapy. A clinical and lab assessment of 32 children with this disorder at birth was made from 1989 to 1999 to find out the variations in time of serum concentrations, occurrence of some clinical symptom or sign of the disease and their intelligence quotient. The 32 studied children presented with reduction of aminoacid levels of 90 to 287 µmol/L (1, 5 mg/dL a 5, 52 mg/dL with respect to birth levels. The majority did not show clinical symptoms or signs of phenylketonuria. Average

PCR múltiple para la detección de los genes sea, seb, sec, sed y see de Staphylococcus aureus: Caracterización de aislamientos de origen alimentario Multiplex PCR for the detection of sea, seb, sec, sed and see genes of Staphylococcus aureus: Characterization of isolates from food

Directory of Open Access Journals (Sweden)

E. A. Manfredi

2010-09-01

Full Text Available La presencia de Staphylococcus aureus en los alimentos representa un riesgo potencial para la salud pública; sus enterotoxinas son el principal factor de virulencia. La detección de las enterotoxinas de S. aureus puede realizarse por ELISA, aunque sólo es posible detectar el pool de enterotoxinas SEA, SEB, SEC, SED y SEE. Los objetivos del presente trabajo fueron optimizar dos técnicas de PCR múltiple para la detección de los genes sea, seb, sec, sed y see de S. aureus y caracterizar un conjunto de 115 aislamientos de Staphylococcus spp. asociados a intoxicaciones alimentarias provenientes de diferentes provincias de Argentina. La caracterización se realizó por pruebas bioquímicas, ELISA y PCR. Sesenta y ocho aislamientos (59,1% fueron positivos por ELISA, mientras que 61 (53% fueron positivos por PCR. De los aislamientos positivos por PCR, 34 (55,7% portaron el gen sea, 9 (14,8% el gen seb, 5 (8,1% el gen see, 4 (6,5% el gen sec, 6 (9,9% los genes sea y seb, 2 (3,3% los genes sea y sec, y 1 (1,7% los genes sea y sed. Este es el primer estudio de caracterización genotípica de aislamientos de S. aureus asociados con brotes de intoxicación alimentaria registrados en distintas provincias argentinas.The presence of Staphylococcus aureus in food represents a potential risk to public health, being its enterotoxins the major virulence factor. Enterotoxin detection can be determined by ELISA, but only for the pool of enterotoxins SEA, SEB, SEC, SED and SEE. The main aims of this study were to optimize two PCR techniques for detection of S. aureus sea, seb, sec, sed and see, and to characterize Staphylococcus spp. isolates associated with food intoxication. Two PCR techniques were optimized and 115 Staphylococcus spp. isolates from Ciudad Autónoma de Buenos Aires, and Buenos Aires, Córdoba, and Neuquén provinces were characterized. The characterization was performed by biochemical tests, ELISA and PCR. Sixty-eight isolates (59.1% were

GAMMA Radiation Effect On Staphylococcus aureus (ATCC 19095) in Cheese MINAS FRESCALIRRADIATED

International Nuclear Information System (INIS)

Amaral Gurgel, M.S.C.C. DO; Spoto, M.H.F.; Domarco, R.E.

1999-01-01

Milk is an excellent medium of culture for development of Staphylococcus aureus. Gamma radiation can be an alternative method to guarantee the safety of the contaminated cheeses. The objective of this research was determine the effects of the gamma radiation on the resistance of S.aureus (ATCC 19095) in cheese M inas Frescal i rradiated. The cheeses elaborated in the Laboratory of Food Irradiation of CENA/USP, were contaminated during their production with 10 6 CFU/mL of culture of S.aureus (ATCC 19095). The cheeses were irradiated with 0; 1; 2; 3 and 4 kGy, maintained under refrigeration condition (5 0C ) and analyzed at 1, 7 and 14 days of storage. The evaluation microbiology was made through the S.aureus survival analysis using Baird Parker selective medium and confirmative test of coagulase, catalase and fermentation aerobics of the manitol. The capacity of enterotoxins production by irradiated S.aureus was detected by the method of Passive Reverse Agglutination Latex. Results showed that 3 kGy is enough to destroy the S.aureus and 2 kGy to inhibited its toxins production

Humanized Mouse Models of Staphylococcus aureus Infection

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Dane Parker

2017-05-01

Full Text Available Staphylococcus aureus is a successful human pathogen that has adapted itself in response to selection pressure by the human immune system. A commensal of the human skin and nose, it is a leading cause of several conditions: skin and soft tissue infection, pneumonia, septicemia, peritonitis, bacteremia, and endocarditis. Mice have been used extensively in all these conditions to identify virulence factors and host components important for pathogenesis. Although significant effort has gone toward development of an anti-staphylococcal vaccine, antibodies have proven ineffective in preventing infection in humans after successful studies in mice. These results have raised questions as to the utility of mice to predict patient outcome and suggest that humanized mice might prove useful in modeling infection. The development of humanized mouse models of S. aureus infection will allow us to assess the contribution of several human-specific virulence factors, in addition to exploring components of the human immune system in protection against S. aureus infection. Their use is discussed in light of several recently reported studies.

Detection and identification of Staphylococcus aureus in raw milk by ...

African Journals Online (AJOL)

STORAGESEVER

2010-04-12

Apr 12, 2010 ... detection and identification of S. aureus in raw milk demonstrated high sensitivity and specificity. Key words: Microarray .... sterile after screening for S. aureus contamination according to the procedure described by Wang ... methods, the microarray method is high throughput, specific, and sensitive and also ...

Unraveling the dynamics of community-associated methicillin-resistant Staphylococcus aureus

NARCIS (Netherlands)

Bootsma, M.C.; Bonten, M.J.M.

2013-01-01

Since the first description of the community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain USA300 [1] in the 1990s, this pathogen has emerged worldwide [2]. Within a decade, USA300 has become the most prevalent cause of community-acquired S. aureus infections in many

Distribution of capsular and surface polysaccharide serotypes of Staphylococcus aureus

NARCIS (Netherlands)

von Eiff, Christof; Taylor, Kimberly L; Mellmann, Alexander; Fattom, Ali I; Friedrich, Alexander W.; Peters, Georg; Becker, Karsten

Because of its ability to cause serious and fatal infections, Staphylococcus aureus remains one of the most feared microorganisms. Methicillin-resistant S. aureus (MRSA) has long been a common pathogen in healthcare facilities, but within the past decade, it has emerged as a problematic pathogen in

Aspartate inhibits Staphylococcus aureus biofilm formation.

Science.gov (United States)

Yang, Hang; Wang, Mengyue; Yu, Junping; Wei, Hongping

2015-04-01

Biofilm formation renders Staphylococcus aureus highly resistant to conventional antibiotics and host defenses. Four D-amino acids (D-Leu, D-Met, D-Trp and D-Tyr) have been reported to be able to inhibit biofilm formation and disassemble established S. aureus biofilms. We report here for the first time that both D- and L-isoforms of aspartate (Asp) inhibited S. aureus biofilm formation on tissue culture plates. Similar biofilm inhibition effects were also observed against other staphylococcal strains, including S. saprophyticus, S. equorum, S. chromogenes and S. haemolyticus. It was found that Asp at high concentrations (>10 mM) inhibited the growth of planktonic N315 cells, but at subinhibitory concentrations decreased the cellular metabolic activity without influencing cell growth. The decreased cellular metabolic activity might be the reason for the production of less protein and DNA in the matrix of the biofilms formed in the presence of Asp. However, varied inhibition efficacies of Asp were observed for biofilms formed by clinical staphylococcal isolates. There might be mechanisms other than decreasing the metabolic activity, e.g. the biofilm phenotypes, affecting biofilm formation in the presence of Asp. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Quality control of direct molecular diagnostics for methicillin-resistant Staphylococcus aureus

NARCIS (Netherlands)

van Belkum, Alex; Niesters, Hubert G M; MacKay, William G; van Leeuwen, Willem B

Ten samples containing various amounts of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus, methicillin-resistant Staphylococcus epidermidis (MRSE), and combinations thereof were distributed to 51 laboratories for molecular diagnostics testing. Samples containing

Long-term mortality after Staphylococcus aureus spondylodiscitis

DEFF Research Database (Denmark)

Aagaard, Theis; Roed, Casper; Larsen, Anders R

2014-01-01

Patients diagnosed with Staphylococcus aureus spondylodiscitis have increased long-term mortality compared with the background population mainly due to infectious, endocrine, cardiovascular, gastrointestinal and alcohol and drug abuse-related diseases.......Patients diagnosed with Staphylococcus aureus spondylodiscitis have increased long-term mortality compared with the background population mainly due to infectious, endocrine, cardiovascular, gastrointestinal and alcohol and drug abuse-related diseases....

Daya Hambat Ekstrak Aloe Vera terhadap pertumbuhan Staphylococcus Aureus

OpenAIRE

Rahmat, drg.Sp,Pros

2011-01-01

Dari hasil penelitian , maka dapat disimpulkan bahwa ekstrak Aloe Vera dapat menghambat pertumbuhan bakteri Stafhylococcus aureus, dan kadar hambat minimal ekstrak Aloe Vera adalah pada konsentrasi 25%. Tujuan Penelitan Ini adalah untuk mengetahui efektifitas ekstrak Aloe vera dalam menghambat pertumbuhan bakteri Stafhylococcus aureus dan daya hambat menimal, (DHM) terhadap pertumbuhan bakteri tersebut. Metode yang digunakan adalah pertumbuhan ekstrak Aloe vera, penegnceran ekstrak , pemur...

Staphylococcus aureus utilizes host-derived lipoprotein particles as sources of exogenous fatty acids.

Science.gov (United States)

Delekta, Phillip C; Shook, John C; Lydic, Todd A; Mulks, Martha H; Hammer, Neal D

2018-03-26

Methicillin-resistant Staphylococcus aureus (MRSA) is a threat to global health. Consequently, much effort has focused on the development of new antimicrobials that target novel aspects of S. aureus physiology. Fatty acids are required to maintain cell viability, and bacteria synthesize fatty acids using the type II fatty acid synthesis pathway (FASII). FASII is significantly different from human fatty acid synthesis, underscoring the therapeutic potential of inhibiting this pathway. However, many Gram-positive pathogens incorporate exogenous fatty acids, bypassing FASII inhibition and leaving the clinical potential of FASII inhibitors uncertain. Importantly, the source(s) of fatty acids available to pathogens within the host environment remains unclear. Fatty acids are transported throughout the body by lipoprotein particles in the form of triglycerides and esterified cholesterol. Thus, lipoproteins, such as low-density lipoprotein (LDL) represent a potentially rich source of exogenous fatty acids for S. aureus during infection. We sought to test the ability of LDLs to serve as a fatty acid source for S. aureus and show that cells cultured in the presence of human LDLs demonstrate increased tolerance to the FASII inhibitor, triclosan. Using mass spectrometry, we observed that host-derived fatty acids present in the LDLs are incorporated into the staphylococcal membrane and that tolerance to triclosan is facilitated by the fatty acid kinase A, FakA, and Geh, a triacylglycerol lipase. Finally, we demonstrate that human LDLs support the growth of S. aureus fatty acid auxotrophs. Together, these results suggest that human lipoprotein particles are a viable source of exogenous fatty acids for S. aureus during infection. IMPORTANCE Inhibition of bacterial fatty acid synthesis is a promising approach to combating infections caused by S. aureus and other human pathogens. However, S. aureus incorporates exogenous fatty acids into its phospholipid bilayer. Therefore, the

FOOD MICROORGANISMS INFLUENCING THE GROWTH OF STAPHYLOCOCCUS AUREUS.

Science.gov (United States)

GRAVES, R R; FRAZIER, W C

1963-11-01

Some 870 cultures of predominating micro-organisms were isolated from market samples of hamburger, fresh pork sausage, fresh fish fillets, stewing beef, frozen chicken pot pie, frozen corn, frozen peas, and pasteurized and raw milk, before and after storage at different temperatures. The isolates were screened for their ability to influence the growth of Staphylococcus aureus strain 196E by means of spot-plate tests on APT and nutrient agars at 25 C. The 438 cultures that influenced the growth of S. aureus were retested on spot plates at 15, 30, and 42 C. After elimination of replicates, the 143 remaining cultures were classified into species, genera, or groups, and 14 different cultures were tested for their influence on the growth of S. aureus in APT broth at 25 C. Over half of the effective cultures inhibited S. aureus and less than half were stimulatory. Pork sausage had the highest proportion of inhibitory cultures, and stewing beef had the lowest. APT agar was better than nutrient agar for screening, and incubation at 15 C gave more effector organisms than at 30 and 42 C. Most of the lactic acid bacteria were inhibitory, but other groups of bacteria contained more stimulatory cultures than inhibitory ones. The three Escherichia coli cultures were stimulatory, but most other Escherichia cultures were inhibitory. Aerobacter and Paracolobactrum isolates were mostly stimulatory. Cultures of other kinds of bacteria were more or less evenly distributed between inhibitory ones and stimulatory ones. Genera containing mostly inhibitory bacteria were Streptococcus, Leuconostoc, and Lactobacillus. Inhibitory species were E. freundii and E. intermedia. Tests with S. aureus in broth indicated that all cultures inhibitory according to spot plates were inhibitory in broth, but stimulation on spot plates did not always indicate the same phenomenon in broth.

Diversity of Staphylococcus aureus Isolates in European Wildlife

Science.gov (United States)

Monecke, Stefan; Gavier-Widén, Dolores; Hotzel, Helmut; Peters, Martin; Guenther, Sebastian; Lazaris, Alexandros; Loncaric, Igor; Müller, Elke; Reissig, Annett; Ruppelt-Lorz, Antje; Shore, Anna C.; Walter, Birgit; Coleman, David C.; Ehricht, Ralf

2016-01-01

Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock-associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation. PMID:27992523

Virulence Factors of Staphylococcus aureus Isolates in an Iranian Referral Children's Hospital.

Science.gov (United States)

Sabouni, Farah; Mahmoudi, Shima; Bahador, Abbas; Pourakbari, Babak; Sadeghi, Reihaneh Hosseinpour; Ashtiani, Mohammad Taghi Haghi; Nikmanesh, Bahram; Mamishi, Setareh

2014-04-01

The clinical importance of Staphylococcus aureus (S. aureus) is attributed to notable virulence factors, surface proteins, toxins, and enzymes as well as the rapid development of drug resistance. The aim of this study was to compare the occurrence of virulence factors produced by S. aureus strains isolated from children in an Iranian referral children's hospital. The presence of genes encoding for the enterotoxins A (sea), B (seb), C (sec), D (sed), TSST-1 (tsst), exfoliative toxin A (eta), and exfoliative toxin B (etb) were detected by Multiplex polymerase chain reaction (PCR) using specific primers. In addition, the standardized Kirby-Bauer disc-diffusion method was performed on Mueller-Hinton agar. In total, 133 S. aureus isolates were obtained from different patients. Of these S. aureus isolates, 64 (48%) were methicillin-resistant S. aureus (MRSA), and all of these tested positive for the mecA gene. Regarding the classical enterotoxin genes, sea gene (40.6%) was the most prevalent followed by seb (19.6%), tsst (12.8%), eta (11.3%), etb (9%), sed (4.5%), and sec (3%). Among methicillin-susceptible S. aureus (MSSA) isolates, seb and tsst were the more prevalent toxins in comparison with MRSA isolates (p  0.05). In our study enterotoxin A was produced by 40.6% of the isolates (48% from MRSA and 33% from MSSA isolates) which was higher than in previous reports. According to our results, strict hygiene and preventative measures during food processing are highly recommended.

Methicillin-resistant Staphylococcus aureus nasal carriage and infection among patients with diabetic foot ulcer.

Science.gov (United States)

Lin, Shin-Yi; Lin, Nai-Yu; Huang, Yu-Yao; Hsieh, Chi-Chun; Huang, Yhu-Chering

2018-06-04

To evaluate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage in patients with diabetic foot ulcer (DFU) in Taiwan, and to assess the concordance between colonizing and clinical MRSA isolates from the patients. A total of 354 nasal specimens were collected from 112 to 242 diabetic patients with and without foot ulcer, respectively. MRSA clinical isolates from DFU wound cultures were collected for comparison. Nasal carriage rate of S. aureus and MRSA was similar between diabetic patients with and without foot ulcer (15.2% vs. 16.9% for S. aureus and 5.4% vs. 1.7% for MRSA). Nasal S. aureus colonization was an independent predictor for wound S. aureus infection (Odds ratio [OR]: 5.33, 95% confidence interval [CI]: 1.61-17.59), so did nasal MRSA colonization (OR: 19.09, 95% CI: 2.12-171.91). The levels of glycated hemoglobin, and the usage with immunosuppressant agent were associated with S. aureus nasal colonization while oral hypoglycemic agent usage a protective factor. Sequence type 59/staphylococcal chromosome cassette mec IV or V, the local endemic community-associated clone, accounted for 42% and 70% of the clinical and colonizing isolates, respectively. Six of 10 patients with paired colonizing and clinical isolates, either MRSA or methicillin-sensitive S. aureus, had a genetically identical strain from a single patient. Less than one-fifth of patients with DFU have nasal S. aureus, including MRSA, colonization; however, the colonization is significantly associated with S. aureus diabetic foot infection. Screening for S. aureus colonizing status in DFU patients might have a potential clinical implication. Copyright © 2018. Published by Elsevier B.V.

Cationic Antimicrobial Peptide LL-37 Is Effective against both Extra- and Intracellular Staphylococcus aureus

Science.gov (United States)

Noore, Jabeen; Noore, Adly

2013-01-01

The increasing resistance of bacteria to conventional antibiotics and the challenges posed by intracellular bacteria, which may be responsible for chronic and recurrent infections, have driven the need for advanced antimicrobial drugs for effective elimination of both extra- and intracellular pathogens. The purpose of this study was to determine the killing efficacy of cationic antimicrobial peptide LL-37 compared to conventional antibiotics against extra- and intracellular Staphylococcus aureus. Bacterial killing assays and an infection model of osteoblasts and S. aureus were studied to determine the bacterial killing efficacy of LL-37 and conventional antibiotics against extra- and intracellular S. aureus. We found that LL-37 was effective in killing extracellular S. aureus at nanomolar concentrations, while lactoferricin B was effective at micromolar concentrations and doxycycline and cefazolin at millimolar concentrations. LL-37 was surprisingly more effective in killing the clinical strain than in killing an ATCC strain of S. aureus. Moreover, LL-37 was superior to conventional antibiotics in eliminating intracellular S. aureus. The kinetic studies further revealed that LL-37 was fast in eliminating both extra- and intracellular S. aureus. Therefore, LL-37 was shown to be very potent and prompt in eliminating both extra- and intracellular S. aureus and was more effective in killing extra- and intracellular S. aureus than commonly used conventional antibiotics. LL-37 could potentially be used to treat chronic and recurrent infections due to its effectiveness in eliminating not only extracellular but also intracellular pathogens. PMID:23274662

Development of a multicomponent Staphylococcus aureus vaccine designed to counter multiple bacterial virulence factors

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Anderson, Annaliesa S.; Miller, Alita A.; Donald, Robert G.K.; Scully, Ingrid L.; Nanra, Jasdeep S.; Cooper, David; Jansen, Kathrin U.

2012-01-01

Staphylococcus aureus is a major cause of healthcare-associated infections and is responsible for a substantial burden of disease in hospitalized patients. Despite increasingly rigorous infection control guidelines, the prevalence and corresponding negative impact of S. aureus infections remain considerable. Difficulties in controlling S. aureus infections as well as the associated treatment costs are exacerbated by increasing rates of resistance to available antibiotics. Despite ongoing efforts over the past 20 years, no licensed S. aureus vaccine is currently available. However, learnings from past clinical failures of vaccine candidates and a better understanding of the immunopathology of S. aureus colonization and infection have aided in the design of new vaccine candidates based on multiple important bacterial pathogenesis mechanisms. This review outlines important considerations in designing a vaccine for the prevention of S. aureus disease in healthcare settings. PMID:22922765

Assessing the potential for raw meat to influence human colonization with Staphylococcus aureus.

Science.gov (United States)

Carrel, Margaret; Zhao, Chang; Thapaliya, Dipendra; Bitterman, Patrick; Kates, Ashley E; Hanson, Blake M; Smith, Tara C

2017-09-07

The role of household meat handling and consumption in the transfer of Staphylococcus aureus (S. aureus) from livestock to consumers is not well understood. Examining the similarity of S. aureus colonizing humans and S. aureus in meat from the stores in which those individuals shop can provide insight into the role of meat in human S. aureus colonization. S. aureus isolates were collected from individuals in rural and urban communities in Iowa (n = 3347) and contemporaneously from meat products in stores where participants report purchasing meat (n = 913). The staphylococcal protein A (spa) gene was sequenced for all isolates to determine a spa type. Morisita indices and Permutational Multivariate Analysis of Variance Using Distance Matrices (PERMANOVA) were used to determine the relationship between spa type composition among human samples and meat samples. spa type composition was significantly different between households and meat sampled from their associated grocery stores. spa types found in meat were not significantly different regardless of the store or county in which they were sampled. spa types in people also exhibit high similarity regardless of residential location in urban or rural counties. Such findings suggest meat is not an important source of S. aureus colonization in shoppers.

Frecuencia de portadores nasales de Staphylococcus aureus resistente a meticilina en personal de salud de hospitales de Nicaragua Frequency of nasal carriers of methicillin-resistant Staphylococcus aureus among health workers in Nicaraguan hospitals

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Mercedes Cáceres

2011-12-01

Full Text Available OBJETIVO: Conocer la frecuencia de portadores nasales de cepas de Staphylococcus aureus resistentes a meticilina (SARM y el patrón de resistencia antimicrobiana de esas cepas obtenidas de trabajadores de la salud de cuatro hospitales de Nicaragua. MÉTODOS: Se realizó un estudio descriptivo, transversal, en el período del 1 de junio de 2009 al 30 de septiembre de 2010. Los hisopados nasales de los trabajadores de la salud que aceptaron voluntariamente participar en el estudio fueron cultivados en medio agar base de detección de resistencia a oxacilina (ORSAB. La identificación de los aislados de S. aureus se realizó por métodos cotidianos y la resistencia a meticilina se determinó por la presencia del gen mecA con la técnica de reacción en cadena de polimerasa. El patrón de resistencia antimicrobiana se detectó por difusión en disco. Cada participante firmó un consentimiento informado con anterioridad a la toma de la muestra. RESULTADOS: Participaron en el estudio 569 trabajadores de la salud, de los cuales 208 eran del hospital de León, 155 de dos hospitales de Chinandega y 206 del de Managua. La frecuencia de portadores nasales de SARM fue de 9,6% en León, 11,6% en Chinandega y 6,7% en Managua. El perfil de resistencia de las cepas SARM fue similar en los cuatro hospitales y todas las cepas fueron sensibles a vancomicina. Del total de cepas SARM aisladas, 15% fueron multirre-sistentes. El porcentaje de resistencia a eritromicina fue el más alto, seguido del de clindamicina. CONCLUSIONES: Los resultados del estudio se pueden considerar una advertencia sobre la circulación de cepas SARM entre el personal de salud de los hospitales participantes y aportan información relevante en relación al perfil de resistencia de las cepas SARM.OBJECTIVE: To determine the frequency of nasal carriers of strains of methicillin-resistant Staphylococcus aureus (MRSA and the antimicrobial resistance pattern of these strains, obtained from health

A sensitive assay for Staphylococcus aureus nucleases

Energy Technology Data Exchange (ETDEWEB)

Kohli, J K; Vakil, B V; Patil, M S; Pandey, V N; Pradhan, D S [Bhabha Atomic Reserach Centre, Bombay (India). Biochemistry Div.

1989-10-01

A sensitive assay for staphylococcal nuclease involving incubation of the enzyme sample with heat-denatured ({sup 3}H) thymidine labelled DNA from E.coli, precipitation with trichloroacetic acid and measurement of the radioactivity of acid-soluble nucleotides released has been developed. The assay is sensitive enough to be used for comparing the levels of nucleases elaborated by different strains of S. aureus as well as for determining the extent of contamination of S. aureus in food and water samples even at levels at which the conventional spectrophotometric and toluidine blue-DNA methods are totally inadequate. (author). 26 refs., 3 figs ., 3 tabs.

Staphylococcus aureus redirects central metabolism to increase iron availability.

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David B Friedman

2006-08-01

Full Text Available Staphylococcus aureus pathogenesis is significantly influenced by the iron status of the host. However, the regulatory impact of host iron sources on S. aureus gene expression remains unknown. In this study, we combine multivariable difference gel electrophoresis and mass spectrometry with multivariate statistical analyses to systematically cluster cellular protein response across distinct iron-exposure conditions. Quadruplicate samples were simultaneously analyzed for alterations in protein abundance and/or post-translational modification state in response to environmental (iron chelation, hemin treatment or genetic (Deltafur alterations in bacterial iron exposure. We identified 120 proteins representing several coordinated biochemical pathways that are affected by changes in iron-exposure status. Highlighted in these experiments is the identification of the heme-regulated transport system (HrtAB, a novel transport system which plays a critical role in staphylococcal heme metabolism. Further, we show that regulated overproduction of acidic end-products brought on by iron starvation decreases local pH resulting in the release of iron from the host iron-sequestering protein transferrin. These findings reveal novel strategies used by S. aureus to acquire scarce nutrients in the hostile host environment and begin to define the iron and heme-dependent regulons of S. aureus.

Antimicrobial Mechanisms of Macrophages and the Immune Evasion Strategies of Staphylococcus aureus

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Flannagan, Ronald S.; Heit, Bryan; Heinrichs, David E.

2015-01-01

Habitually professional phagocytes, including macrophages, eradicate microbial invaders from the human body without overt signs of infection. Despite this, there exist select bacteria that are professional pathogens, causing significant morbidity and mortality across the globe and Staphylococcus aureus is no exception. S. aureus is a highly successful pathogen that can infect virtually every tissue that comprises the human body causing a broad spectrum of diseases. The profound pathogenic capacity of S. aureus can be attributed, in part, to its ability to elaborate a profusion of bacterial effectors that circumvent host immunity. Macrophages are important professional phagocytes that contribute to both the innate and adaptive immune response, however from in vitro and in vivo studies, it is evident that they fail to eradicate S. aureus. This review provides an overview of the antimicrobial mechanisms employed by macrophages to combat bacteria and describes the immune evasion strategies and some representative effectors that enable S. aureus to evade macrophage-mediated killing. PMID:26633519

Treatment of methicillin-resistant Staphylococcus aureus in Latin America Tratamento de Staphylococcus aureus resistente à meticilina na América Latina

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Carlos M Luna

2010-12-01

Full Text Available The global spread of methicillin-resistant Staphylococcus aureus (MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin AmericaA propagação global de Staphylococcus aureus resistente à meticilina (methicillin-resistant Staphylococcus aureus - MRSA significa que se trata agora de um patógeno de interesse para a saúde pública mundial. Na América Latina, o MRSA é altamente prevalente, com a proporção de S. aureus resistente à meticilina em ascensão, no entanto os recursos para o tratamento da infecção são limitados. Embora existam várias diretrizes para o tratamento de infecções por MRSA, muitas são elaboradas para a América do Norte ou a Europa e precisam ser adaptadas para sua utilização na América Latina. Neste artigo, procuramos destacar a importância do tratamento adequado do MRSA nas unidades de saúde e na comunidade na América Latina. Apresentamos um resumo das diretrizes e dos antibióticos disponíveis, e discutimos considerações específicas para os médicos que tratam de MRSA na América Latina.

The bactericidal mechanism of action against Staphylococcus aureus for AgO nanoparticles

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Shen, Wenning, E-mail: shenwenning@qq.com [School of Materials Science and Engineering, Xi' an University of Technology, No. 5 South Jinhua Road, Xi' an 710048 (China); Li, Pin [School of Materials Science and Engineering, Xi' an University of Technology, No. 5 South Jinhua Road, Xi' an 710048 (China); Feng, Hui [Shaanxi Institute of Zoology, Xi' an 710032 (China); Ge, Yanfeng; Liu, Zheng; Feng, Lajun [School of Materials Science and Engineering, Xi' an University of Technology, No. 5 South Jinhua Road, Xi' an 710048 (China)

2017-06-01

To identify the mechanistic effects of AgO nanoparticles on Gram-positive bacteria, S. aureus cells suspended in phosphate buffer solution (PBS) and deionized water were separately treated using AgO nanoparticles at different concentrations. The phase composition changes of the bactericide after killing S. aureus and the cellular responses of S. aureus to AgO were characterized by X-ray diffraction, atomic absorption spectrophotometer, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy. The results show that AgO nanoparticles could kill S. aureus suspended in PBS and deionized water. The bactericidal effect of AgO bactericide against S. aureus in water was better than that in PBS, due to the formation of Ag{sub 3}PO{sub 4} from the reaction between AgO and PBS. AgO nanoparticles exerted their bactericidal activity by multiple processes. AgO nanoparticles adhered to the surface of S. aureus cells firstly, then induced physical alterations in cell morphology and released silver ions, leading to initial injuries of cell membrane. Once membrane damage occurred, they entered the cells, and damaged the intracellular materials, eventually causing severe morphological and structural injuries to the cells and leakage of cytoplasm. - Highlights: • S. aureus in water was more sensitive to AgO than in PBS, since AgO reacted with PBS and formed Ag{sub 3}PO{sub 4}. • After killing S. aureus in water, AgO did not changed. • AgO particles attached to cell surface then interacted with the cells, resulting in the increase of released silver contents. • Cell membrane damages by AgO nanoparticles were supported by the leakages of K{sup +}, proteins and DNA. • Serious cell morphological and structural changes were caused by AgO nanoparticles.

The bactericidal mechanism of action against Staphylococcus aureus for AgO nanoparticles

International Nuclear Information System (INIS)

Shen, Wenning; Li, Pin; Feng, Hui; Ge, Yanfeng; Liu, Zheng; Feng, Lajun

2017-01-01

To identify the mechanistic effects of AgO nanoparticles on Gram-positive bacteria, S. aureus cells suspended in phosphate buffer solution (PBS) and deionized water were separately treated using AgO nanoparticles at different concentrations. The phase composition changes of the bactericide after killing S. aureus and the cellular responses of S. aureus to AgO were characterized by X-ray diffraction, atomic absorption spectrophotometer, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy. The results show that AgO nanoparticles could kill S. aureus suspended in PBS and deionized water. The bactericidal effect of AgO bactericide against S. aureus in water was better than that in PBS, due to the formation of Ag 3 PO 4 from the reaction between AgO and PBS. AgO nanoparticles exerted their bactericidal activity by multiple processes. AgO nanoparticles adhered to the surface of S. aureus cells firstly, then induced physical alterations in cell morphology and released silver ions, leading to initial injuries of cell membrane. Once membrane damage occurred, they entered the cells, and damaged the intracellular materials, eventually causing severe morphological and structural injuries to the cells and leakage of cytoplasm. - Highlights: • S. aureus in water was more sensitive to AgO than in PBS, since AgO reacted with PBS and formed Ag 3 PO 4 . • After killing S. aureus in water, AgO did not changed. • AgO particles attached to cell surface then interacted with the cells, resulting in the increase of released silver contents. • Cell membrane damages by AgO nanoparticles were supported by the leakages of K + , proteins and DNA. • Serious cell morphological and structural changes were caused by AgO nanoparticles.

Molecular Characteristics of Staphylococcus aureus Causing Bovine Mastitis between 2014 and 2015.

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Li, Tianming; Lu, Huiying; Wang, Xing; Gao, Qianqian; Dai, Yingxin; Shang, Jun; Li, Min

2017-01-01

Staphylococcus aureus is highly pathogenic and can cause diseases in both humans and domestic animals. In animal species, including ruminants, S. aureus may cause severe or sub-clinical mastitis. This study aimed to investigate the molecular profile, antimicrobial resistance, and genotype/phenotype correlation of 212 S. aureus isolates recovered from cases of bovine mastitis from 2014 to 2015 in the Shanghai and Zhejiang areas of China. Nineteen sequence types (STs) were determined by multi-locus sequence typing, while the dominant ST was ST97, followed by ST520, ST188, ST398, ST7, and ST9. Within 14 methicillin-resistant S. aureus (MRSA) isolates and 198 methicillin-susceptible S. aureus (MSSA) isolates, ST97 was the predominant MSSA clone and ST9-MRSA-SCCmecXII-spa t899 was the most common MRSA clone. The MRSA strains showed much higher rates of resistance to multiple antibiotics than did MSSA strains. Compared with other MSSA strains, MSSA ST398 was more resistant to clindamycin, erythromycin, and ciprofloxacin. No isolates were resistant to vancomycin, teicoplanin, or linezolid. The molecular profiles of the virulence genes varied in different strains. ST520 strains carried seg-sei-sem-sen-seo genes, and ST9 and ST97 harbored sdrD-sdrE genes. Virulence phenotype analysis showed diversity in different clones. Biofilm formation ability was significantly enhanced in ST188 and ST7, and red blood cell lysis capacity was relatively strong in all S. aureus strains of animal origin except ST7. Our results indicate that MSSA was the predominant S. aureus strain causing bovine mastitis in eastern regions of China. However, the presence of multidrug resistant and toxigenic MRSA clone ST9 suggests that comprehensive surveillance of S. aureus infection should be implemented in the management of animal husbandry products.

Antividad antibacteriana In vitro de extractos de piper angustifolium (matico) y matricaria chamomilla (manzanilla) en cepas de staphylococcus aureus con resistencia múltiple

OpenAIRE

Zuta Arriola, Noemí

2014-01-01

El Staphylococcus aureus es el microorganismo más importante causante de infecciones intrahospitalarias y presenta una resistencia múltiple a antibióticos, lo cual conduce a diseñar medidas de prevención dirigidas a controlar y disminuir la resistencia antibiótica. Actualmente se sabe que muchas plantas medicinales tienen actividad antibacteriana, pero su posible efecto frente a bacterias multirresistentes como es el caso de S. aures aislada de muestras clínicas no reúne mayores referencias. ...

Frequency of Reduced Vancomycin Susceptibility among Clinical Staphylococcus aureus Isolated in Ahvaz Iran

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Mojtaba Moosavian

2015-11-01

Full Text Available Introduction:   One   of   the   most   important   agents   in   hospital-acquired   infections   is Staphylococcus aureus. Treatment of methicillin-resistant S. aureus (MRSA infections with decreased susceptibility to vancomycin has recently been more difficult. The aim of this study was to evaluate the possible presence of vancomycin intermediate S. aureus (VISA and vancomycin- resistant S. aureus (VRSA and also to determine the frequency of MRSA in clinical specimens.Methods: In this study, 195 S. aureus isolates were collected from the patients were examined. All of the isolates were identified using standard biochemical tests.  Susceptibility of S. aureus isolates against 10 antibiotics was detected by disk diffusion method and was followed by E-test and vancomycin screen agar methods. Minimum inhibitory concentration (MIC of vancomycin was determined according to the CLSI guidelines.  Also, detection of mecA gene was performed by PCR and finally, the results were compared.Results: All of the isolates were susceptible to vancomycin (i.e. MIC range of vancomycin was between 0.25-2 µg/ml. Out of 195 S. aureus isolates, 99 isolates (50.8% were resistant to methicillin, and mecA gene was detected in 96 isolates. These results also showed that the highest and lowest resistance rate of isolates was to penicillin (96.9% and chloramphenicol (0%, respectively.Conclusion: Our findings showed that vancomycin can still be used as a valuable drug for treatment of S. aureus infections in our region. However, periodic evaluation of vancomycin MIC of S. aureus isolates is critical for monitoring MRSA and preventing the spread of VISA or VRSA among patients.

Intracellular persisting Staphylococcus aureus is the major pathogen in recurrent tonsillitis.

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Andreas E Zautner

Full Text Available BACKGROUND: The two major indications for tonsillectomy are recurrent tonsillitis (RT and peritonsillar abscess (PTA. Unlike PTAs, which are primarily treated surgically, RT is often cured by tonsillectomy only after a series of failed drug therapy attempts. Although the bacteriological background of RT has been studied, the reason for the lack of success of conservative therapeutic approaches is not well understood. METHODS: In a prospective study, tonsil specimens from 130 RT patients and 124 PTA patients were examined for the presence of extra- and intracellular bacteria using antibiotic protection assays. Staphylococcus aureus isolates from RT patients were characterized by pulsed-field gel electrophoresis (PFGE, spa-typing and MSCRAMM-gene-PCR. Their ability for biofilm formation was tested and their cell invasiveness was confirmed by a flow cytometric invasion assay (FACS, fluorescent in situ hybridization (FISH and immunohistochemistry. FINDINGS: S. aureus was the predominant species (57.7% in RT patients, whereas Streptococcus pyogenes was most prevalent (20.2% in PTA patients. Three different assays (FACS, FISH, antibiotic protection assay showed that nearly all RT-associated S. aureus strains were located inside tonsillar cells. Correspondingly, the results of the MSCRAMM-gene-PCRs confirmed that 87% of these S. aureus isolates were invasive strains and not mere colonizers. Based upon PFGE analyses of genomic DNA and on spa-gene typing the vast majority of the S. aureus isolates belonged to different clonal lineages. CONCLUSIONS: Our results demonstrate that intracellular residing S. aureus is the most common cause of RT and indicate that S. aureus uses this location to survive the effects of antibiotics and the host immune response. A German translation of the Abstract is provided as supplementary material (Abstract S1.

The clinical and molecular epidemiology of Staphylococcus aureus infections in Fiji.

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Jenney, Adam; Holt, Deborah; Ritika, Roselyn; Southwell, Paul; Pravin, Shalini; Buadromo, Eka; Carapetis, Jonathan; Tong, Steven; Steer, Andrew

2014-03-24

There are few data describing the microbiology and genetic typing of Staphylococcus aureus that cause infections in developing countries. In this study we observed S. aureus infections in Pacific Island nation of Fiji in both the community and hospital setting with an emphasis on clonal complex (CC) genotyping and antimicrobial susceptibility. S. aureus was commonly found in impetigo lesions of school children and was recovered from 57% of impetigo lesions frequently in conjunction with group A streptococcal infection. Methicillin-resistant S. aureus (MRSA) comprised 7% (20/299) of isolates and were all non-multi-resistant and all genotyped as CC1. In contrast, there was a diverse selection of 17 CCs among the 105 genotyped methicillin-susceptible S.aureus (MSSA) strains. Isolates of the rare, phylogenetically divergent and non-pigmented CC75 lineage (also called S. argenteus) were found in Fiji.From hospitalized patients the available 36 MRSA isolates from a 9-month period were represented by five CCs. The most common CCs were CC1 and CC239. CC1 is likely to be a community-acquired strain, reflecting what was found in the school children, whereas the CC239 is the very successful multi-drug resistant MRSA nosocomial lineage. Of 17 MSSA isolates, 59% carried genes for Panton-Valentine leukocidin. The S. aureus bacteraemia incidence rate of 50 per 100,000 population is among the highest reported in the literature and likely reflects the high overall burden of staphylococcal infections in this population. S. aureus is an important cause of disease in Fiji and there is considerable genotypic diversity in community skin infections in Fijian schoolchildren. Community acquired- (CA)- MRSA is present at a relatively low prevalence (6.7%) and was solely to CC1 (CA-MRSA). The globally successful CC239 is also a significant pathogen in Fiji.

Filaments in curved streamlines: rapid formation of Staphylococcus aureus biofilm streamers

International Nuclear Information System (INIS)

Kevin Kim, Minyoung; Drescher, Knut; Shun Pak, On; Stone, Howard A; Bassler, Bonnie L

2014-01-01

Biofilms are surface-associated conglomerates of bacteria that are highly resistant to antibiotics. These bacterial communities can cause chronic infections in humans by colonizing, for example, medical implants, heart valves, or lungs. Staphylococcus aureus, a notorious human pathogen, causes some of the most common biofilm-related infections. Despite the clinical importance of S. aureus biofilms, it remains mostly unknown how physical effects, in particular flow, and surface structure influence biofilm dynamics. Here we use model microfluidic systems to investigate how environmental factors, such as surface geometry, surface chemistry, and fluid flow affect biofilm development of S. aureus. We discovered that S. aureus rapidly forms flow-induced, filamentous biofilm streamers, and furthermore if surfaces are coated with human blood plasma, streamers appear within minutes and clog the channels more rapidly than if the channels are uncoated. To understand how biofilm streamer filaments reorient in flows with curved streamlines to bridge the distances between corners, we developed a mathematical model based on resistive force theory of slender filaments. Understanding physical aspects of biofilm formation of S. aureus may lead to new approaches for interrupting biofilm formation of this pathogen. (paper)

Methicillin-resistant Staphylococcus aureus: a controversial food-borne pathogen.

Science.gov (United States)

Sergelidis, D; Angelidis, A S

2017-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of severe healthcare-associated (HA) infections. Although during the last decade the incidence of HA invasive infections has dropped, the incidence of community-associated MRSA (CA-MRSA) infections has risen among the general population. Moreover, CA-MRSA, livestock-associated MRSA (LA-MRSA) and HA-MRSA (HA-MRSA) can be found in foods intended for human consumption. Several studies from different geographical areas have reported the presence of enterotoxin genes in several MRSA food isolates. Molecular typing studies have revealed genetic relatedness of these enterotoxigenic isolates with isolates incriminated in human infections. The contamination sources for foods, especially animal-origin foods, may be livestock as well as humans involved in animal husbandry and food-processing. Under favourable environmental conditions for growth and enterotoxin production, enterotoxigenic S. aureus isolates present in foods can cause staphylococcal food poisoning (SFP), irrespective of the contamination origin. Owing to the typically moderate clinical manifestations of SFP, the S. aureus strains responsible for SFP (cases or outbreaks) are frequently either not identified or not further characterized. Antimicrobial susceptibility testing is rarely performed, because administration of antimicrobial therapy is not required in the vast majority of cases. Staphylococcal food poisoning is the result of consumption of foods with preformed enterotoxins. Hence, similar to methicillin-sensitive enterotoxigenic S. aureus, enterotoxigenic MRSA can also act as food-borne pathogens upon favourable conditions for growth and enterotoxin production. The severity of the intoxication is not related to the antimicrobial resistance profile of the causative S. aureus strain and therefore MRSA food-borne outbreaks are not expected to be more severe. This review evaluates the potential of methicillin-resistant Staphylococcus

Secreted Immunomodulatory Proteins of Staphylococcus aureus Activate Platelets and Induce Platelet Aggregation.

Science.gov (United States)

Binsker, Ulrike; Palankar, Raghavendra; Wesche, Jan; Kohler, Thomas P; Prucha, Josephine; Burchhardt, Gerhard; Rohde, Manfred; Schmidt, Frank; Bröker, Barbara M; Mamat, Uwe; Pané-Farré, Jan; Graf, Anica; Ebner, Patrick; Greinacher, Andreas; Hammerschmidt, Sven

2018-04-01

Staphylococcus aureus can cause bloodstream infections associated with infective endocarditis (IE) and disseminated intravascular coagulopathy (DIC). Both complications involve platelets. In view of an increasing number of antibiotic-resistant strains, new approaches to control systemic S. aureus infection are gaining importance. Using a repertoire of 52 recombinant S. aureus proteins in flow cytometry-based platelet activation and aggregation assays, we identified, in addition to the extracellular adherence protein Eap, three secreted staphylococcal proteins as novel platelet activating proteins. Eap and the chemotaxis inhibitory protein of S. aureus (CHIPS), the formyl peptide receptor-like 1 inhibitory protein (FLIPr) and the major autolysin Atl induced P-selectin expression in washed platelets and platelet-rich plasma. Similarly, AtlA, CHIPS and Eap induced platelet aggregation in whole blood. Fluorescence microscopy illustrated that P-selectin expression is associated with calcium mobilization and re-organization of the platelet actin cytoskeleton. Characterization of the functionally active domains of the major autolysin AtlA and Eap indicates that the amidase domain of Atl and the tandem repeats 3 and 4 of Eap are crucial for platelet activation. These results provide new insights in S. aureus protein interactions with platelets and identify secreted proteins as potential treatment targets in case of antibiotic-resistant S. aureus infection. Schattauer GmbH Stuttgart.

Regulation of Expression of Oxacillin-Inducible Methionine Sulfoxide Reductases in Staphylococcus aureus

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Kyle R. Baum

2015-01-01

Full Text Available Cell wall-active antibiotics cause induction of a locus that leads to elevated synthesis of two methionine sulfoxide reductases (MsrA1 and MsrB in Staphylococcus aureus. To understand the regulation of this locus, reporter strains were constructed by integrating a DNA fragment consisting of the msrA1/msrB promoter in front of a promoterless lacZ gene in the chromosome of wild-type and MsrA1-, MsrB-, MsrA1/MsrB-, and SigB-deficient methicillin-sensitive S. aureus strain SH1000 and methicillin-resistant S. aureus strain COL. These reporter strains were cultured in TSB and the cellular levels of β-galactosidase activity in these cultures were assayed during different growth phases. β-galactosidase activity assays demonstrated that the lack of MsrA1, MsrB, and SigB upregulated the msrA1/msrB promoter in S. aureus strain SH1000. In S. aureus strain COL, the highest level of β-galactosidase activity was observed under the conditions when both MsrA1 and MsrB proteins were absent. The data suggest that the msrA1/msrB locus, in part, is negatively regulated by MsrA1, MsrB, and SigB in S. aureus.

Actividad del (2E-3-(2, 3-dimetoxifenil-1-(4-metilfenil prop-2-en-1-ona en presencia del poli(ácido maleico-co-2-vinil-pirrolidona sobre un aislamiento clínico de Staphylococcus aureus productor de β-lactamasas = Activity of (2E-3-(2, 3-dimetoxifenil-1-(4-metilfenil prop-2-en-1-ona in the presence of poli(maleic acid-co-2-vinyl-pyrrolidone on a b-lactamase producing clinical isolate of Staphylococcus aureus

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Arenas Fernández, Tatiana

2012-01-01

Full Text Available Introducción: debido a la problemática actual de fármaco-resistencia hacia los antibióticos b-lactámicos, se ha hecho necesario, en busca de una solución, trabajar con nuevas moléculas con potencial farmacológico, así como utilizar novedosos sistemas poliméricos como matrices o excipientes farmacéuticos.Objetivo: evaluar la actividad antibiótica de la ampicilina, combinada con un compuesto sintético de tipo chalcona, denominado (2E-3-(2,3-dimetoxifenil-1-(4-metilfenilprop-2-en- 1-ona, sobre un aislamiento clínico de Staphylococcus aureus resistente a penicilinas, en presencia de una matriz polimérica hidrosoluble denominada poli(ácido maleico-co-2-vinilpirrolidona.Materiales y métodos: el compuesto sintético y la matriz polimérica se obtuvieron por métodos descritos en la literatura. Se usó un aislamiento clínico de Staphylococcus aureus resistente a penicilinas y se hicieron ensayos de actividad antibiótica por la técnica de macrodilución en caldo, de la cual se obtuvieron las concentraciones inhibidoras mínimas de los compuestos evaluados.Resultados: la mezcla ampicilina-chalcona muestra un efecto antibiótico menor que el de su referente ampicilina-sulbactam. No obstante, cuando se utiliza la matriz polimérica en combinación con la ampicilina-chalcona se aprecia un incremento significativo de la actividad antibiótica, evidenciado en que la concentración inhibidora mínima es la mitad de la del referente comercial.

Identification of single nucleotide polymorphisms associated with hyperproduction of alpha-toxin in Staphylococcus aureus.

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Xudong Liang

2011-04-01

Full Text Available The virulence factor α-toxin (hla is needed by Staphylococcus aureus in order to cause infections in both animals and humans. Although the complicated regulation of hla expression has been well studied in human S. aureus isolates, the mechanisms of of hla regulation in bovine S. aureus isolates remain undefined. In this study, we found that many bovine S. aureus isolates, including the RF122 strain, generate dramatic amounts of α-toxin in vitro compared with human clinical S. aureus isolates, including MRSA WCUH29 and MRSA USA300. To elucidate potential regulatory mechanisms, we analyzed the hla promoter regions and identified predominant single nucleotide polymorphisms (SNPs at positions -376, -483, and -484 from the start codon in α-toxin hyper-producing isolates. Using site-directed mutagenesis and hla promoter-gfp-luxABCDE dual reporter approaches, we demonstrated that the SNPs contribute to the differential control of hla expression among bovine and human S. aureus isolates. Using a DNA affinity assay, gel-shift assays and a null mutant, we identified and revealed that an hla positive regulator, SarZ, contributes to the involvement of the SNPs in mediating hla expression. In addition, we found that the bovine S. aureus isolate RF122 exhibits higher transcription levels of hla positive regulators, including agrA, saeR, arlR and sarZ, but a lower expression level of hla repressor rot compared to the human S. aureus isolate WCUH29. Our results indicate α-toxin hyperproduction in bovine S. aureus is a multifactorial process, influenced at both the genomic and transcriptional levels. Moreover, the identification of predominant SNPs in the hla promoter region may provide a novel method for genotyping the S. aureus isolates.

Factors Associated with Worse Lung Function in Cystic Fibrosis Patients with Persistent Staphylococcus aureus.

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Sibylle Junge

Full Text Available Staphylococcus aureus is an important pathogen in cystic fibrosis (CF. However, it is not clear which factors are associated with worse lung function in patients with persistent S. aureus airway cultures. Our main hypothesis was that patients with high S. aureus density in their respiratory specimens would more likely experience worsening of their lung disease than patients with low bacterial loads.Therefore, we conducted an observational prospective longitudinal multi-center study and assessed the association between lung function and S. aureus bacterial density in respiratory samples, co-infection with other CF-pathogens, nasal S. aureus carriage, clinical status, antibiotic therapy, IL-6- and IgG-levels against S. aureus virulence factors.195 patients from 17 centers were followed; each patient had an average of 7 visits. Data were analyzed using descriptive statistics and generalized linear mixed models. Our main hypothesis was only supported for patients providing throat specimens indicating that patients with higher density experienced a steeper lung function decline (p<0.001. Patients with exacerbations (n = 60, S. aureus small-colony variants (SCVs, n = 84 and co-infection with Stenotrophomonas maltophilia (n = 44 had worse lung function (p = 0.0068; p = 0.0011; p = 0.0103. Patients with SCVs were older (p = 0.0066 and more often treated with trimethoprim/sulfamethoxazole (p = 0.0078. IL-6 levels positively correlated with decreased lung function (p<0.001, S. aureus density in sputa (p = 0.0016, SCVs (p = 0.0209, exacerbations (p = 0.0041 and co-infections with S. maltophilia (p = 0.0195 or A. fumigatus (p = 0.0496.In CF-patients with chronic S. aureus cultures, independent risk factors for worse lung function are high bacterial density in throat cultures, exacerbations, elevated IL-6 levels, presence of S. aureus SCVs and co-infection with S. maltophilia.ClinicalTrials.gov NCT00669760.

Aleitamento materno e colonização mucocutânea pelo Staphylococcus aureus na criança com dermatite atópica Breastfeeding and mucosal and cutaneous colonization by Staphylococcus aureus in atopic children

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Raissa Massaia Londero Chemello

2011-06-01

Full Text Available FUNDAMENTOS: Não há consenso quanto ao efeito do aleitamento materno no desenvolvimento da dermatite atópica. É necessário aprofundar conhecimentos sobre possíveis fatores envolvidos nessa relação, como a influência do aleitamento materno na colonização do paciente atópico pelo Staphylococcus aureus (S. aureus. OBJETIVO: Avaliar uma potencial associação entre aleitamento materno e colonização pelo S. aureus nas crianças atópicas. MÉTODOS: Estudo transversal envolvendo 79 crianças atópicas de 4-24 meses, de ambos os sexos, em acompanhamento no Ambulatório de Dermatologia Sanitária de Porto Alegre, e 72 mães. Registraram-se dados clinicoepidemiológicos e de alimentação das crianças. Pesquisou-se a presença do S. aureus em swab nasal e cutâneo nas crianças e swab nasal das respectivas mães. Para análise dos dados, realizaram-se os testes qui-quadrado de Pearson e exato de Fischer. RESULTADOS: Entre as crianças amamentadas, S. aureus foi encontrado nas cavidades nasais de oito (25,8% e na pele (fossas cubitais de quatro (12,9%. Entre as não amamentadas, encontrou-se S. aureus nas cavidades nasais de dez (20,8% e na pele de 11 (22,9%. Entre as mães, 16 (22,2% apresentaram crescimento de S. aureus no material proveniente do swab nasal. Não se observou associação significativa entre aleitamento materno e colonização pelo S. aureus das cavidades nasais ou da pele das crianças. Entretanto, houve concordância entre a colonização pelo S. aureus nas cavidades nasais das mães e nas cavidades nasais e/ou na pele dos filhos. Das 72 duplas, houve concordância em 56 (77,8%. CONCLUSÃO: O aleitamento materno parece não influenciar a colonização mucocutânea pelo S. aureus em crianças com dermatite atópicaBACKGROUND: Studies on the effects of breastfeeding on the development of Atopic Dermatitis (AD have shown controversial results. The importance of this condition deserves further studies; in particular, it

Epidemiology of Streptococcus pneumoniae and Staphylococcus aureus colonization in healthy Venezuelan children

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Quintero, B.; Araque, M.; van der Gaast-de Jongh, C.; Escalona, F.; Correa, M.; Morillo-Puente, S.; Vielma, S.; Hermans, P. W. M.

2010-01-01

Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5?years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae?S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6...

Virulence Factors and Antibiotic Susceptibility of Staphylococcus aureus Isolates in Ready-to-Eat Foods: Detection of S. aureus Contamination and a High Prevalence of Virulence Genes

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Suat Moi Puah

2016-02-01

Full Text Available Staphylococcus aureus is one of the leading causes of food poisoning. Its pathogenicity results from the possession of virulence genes that produce different toxins which result in self-limiting to severe illness often requiring hospitalization. In this study of 200 sushi and sashimi samples, S. aureus contamination was confirmed in 26% of the food samples. The S. aureus isolates were further characterized for virulence genes and antibiotic susceptibility. A high incidence of virulence genes was identified in 96.2% of the isolates and 20 different virulence gene profiles were confirmed. DNA amplification showed that 30.8% (16/52 of the S. aureus carried at least one SE gene which causes staphylococcal food poisoning. The most common enterotoxin gene was seg (11.5% and the egc cluster was detected in 5.8% of the isolates. A combination of hla and hld was the most prevalent coexistence virulence genes and accounted for 59.6% of all isolates. Antibiotic resistance studies showed tetracycline resistance to be the most common at 28.8% while multi-drug resistance was found to be low at 3.8%. In conclusion, the high rate of S. aureus in the sampled sushi and sashimi indicates the need for food safety guidelines.

Factors associated with worse lung function in cystic fibrosis patients with persistent staphylococcus aureus

NARCIS (Netherlands)

Junge, S. (Sibylle); Görlich, D. (Dennis); Reijer, M.D. (Martijn Den); B. Wiedemann (Baerbel); B. Tümmler (Burkhard); H. Ellemunter; Dübbers, A. (Angelika); Küster, P. (Peter); M. Ballmann; Koerner-Rettberg, C. (Cordula); Große-Onnebrink, J. (Jörg); Heuer, E. (Eberhardt); Sextro, W. (Wolfgang); Mainz, J.G. (Jochen G.); Hammermann, J. (Jutta); Riethmüller, J. (Joachim); Graepler-Mainka, U.M. (Ute M.); Staab, D. (Doris); Wollschläger, B. (Bettina); Szczepanski, R. (Rüdiger); A. Schuster (Antje); Tegtmeyer, F.-K. (Friedrich-Karl); Sutharsan, S. (Sivagurunathan); Wald, A. (Alexandra); Nofer, J.-R. (Jerzy-Roch); W.J.B. van Wamel (Willem); Becker, K. (Karsten); Peters, G. (Georg); Kahl, B.C. (Barbara C.)

2016-01-01

textabstractBackground Staphylococcus aureus is an important pathogen in cystic fibrosis (CF). However, it is not clear which factors are associated with worse lung function in patients with persistent S. aureus airway cultures. Our main hypothesis was that patients with high S. aureus density in

The therapeutic effect of Chlorogenic acid against Staphylococcus aureus infection through Sortase A inhibition

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Lin eWang

2015-10-01

Full Text Available The emergence and wide spread of multi-drug resistant Staphylococcus aureus (S. aureus requires the development of new therapeutic agents with alternative modes of action. Anti-virulence strategies are hoped to meet that need. Sortase A (SrtA has attracted great interest as a potential drug target to treat infections caused by S. aureus, as many of the surface proteins displayed by SrtA function as virulence factors by mediating bacterial adhesion to specific organ tissues, invasion of host cells, and evasion of the host-immune responses. It has been suggested that inhibitors of SrtA might be promising candidates for the treatment and/or prevention of S. aureus infections. In this study, we report that Chlorogenic acid (CHA, a natural compound that lacks significant anti–S. aureus activity, inhibit the activity of SrtA in vitro (IC50=33.86±5.55μg/ml and the binding of S. aureus to fibrinogen (Fg. Using molecular dynamics simulations and mutagenesis assays, we further demonstrate that CHA binds to the binding sites of C184 and G192 in the SrtA. In vivo studies demonstrated that CHA prevent mice from S. aureus-induced renal abscess, resulting in a significant survival advantage. These findings indicate that CHA is a promising therapeutic compound against SrtA during S. aureus infections.

Haplotipos del gen de la globina beta en portadores de hemoglobina S en Colombia

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Claudia Liliana Durán

2012-03-01

Resultados. Los haplotipos de la hemoglobina S encontrados con mayor frecuencia en la muestra analizada son de origen africano y su orden de aparición fue mayor para el haplotipo Bantú (36,4 %, seguido por Senegal (30,3 %, Benín (21,2 % y Camerún (12,1 %. La electroforesis de hemoglobina confirmó el fenotipo AS; la dosificación de hemoglobina fetal mostró niveles por debajo de 1 % y los parámetros hematológicos analizados mostraron valores normales en el 100 % de los individuos. Conclusión. Los haplotipos de la HbS encontrados con mayor frecuencia en la muestra estudiada eran de origen africano y su distribución variaba de acuerdo con el lugar de prodedencia del individuo. La mayor frecuencia correspodió al haplotipo Bantú.   DOI: http://dx.doi.org/10.7705/biomedica.v32i1.600

Growth, mortality and reproduction of the blue tilapia Oreochromis aureus (Perciformes: Cichlidae in the Aguamilpa Reservoir, Mexico

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Emilio Peña Messina

2010-12-01

Full Text Available Tilapia production has increased in Aguamilpa Reservoir, in Nayarit, Mexico, in the last few years and represents a good economic activity for rural communities and the country. We determined growth parameters, mortality and reproductive aspects for 2 413 specimens of blue tilapia Oreochromis aureus in this reservoir. Samples were taken monthly from July 2000 through June 2001, of which 1 371 were males and 1 042 were females. Standard length (SL and total weight (TW were measured in each organism. The SL/TW relationships through power models for sexes were determined. The growth parameters L ∞, k, and t0 of the von Bertalanffy equation were estimated using frequency distribution of length through ELEFAN-I computer program. Finally the reproductive cycle and size of first maturity were established using morph chromatic maturity scale. The results suggested that the males and females had negative allometric growth (bLos parámetros de crecimiento, reproducción y mortalidad de Oreochormis aureus en el embalse de Aguamilpa, México fueron determinados. Un total de 2 413 organismos se recolectaron entre julio de 2000 y junio de 2001, de los cuales 1 371 fueron machos y 1 042 hembras. Se analizó la relación longitud estándar (LE y peso total (PT mediante modelos potenciales. Los parámetros de crecimiento de la ecuación de von Bertalanffy fueron estimados usando la distribución de frecuencia de tallas con ayuda del programa ELEFAN-I. Finalmente se determinó el ciclo reproductivo, talla de primera madurez y fecundidad. Los resultados indicaron que tanto hembras como machos presentaron crecimiento alométrico negativo. Se encontraron diferencias significativas entre hembras y machos para la relación LE- PT sugiriendo modelos separados por sexo. No existieron diferencias significativas en el crecimiento por sexo y la tasa de explotación estimada (0.57/año sugiere que la pesquería durante el periodo de estudio mostró signos de

Increasing rate of daptomycin non-susceptible strains of Staphylococcus aureus in patients with atopic dermatitis

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Izabela Błażewicz

2017-12-01

Full Text Available Introduction : Daptomycin is a cyclic lipopeptide that is bactericidal against Staphylococcus aureus , including methicillin-resistant S. aureus (MRSA, vancomycin-intermediate S. aureus (VISA and vancomycin-resistant S. aureus (VRSA strains. Daptomycin exerts its antimicrobial effect by a calcium-dependent interaction with the cytoplasmic membrane resulting in depolarization, ion loss and rapid cell death. Unfortunately, loss of daptomycin susceptibility in S. aureus in the clinical setting has been noted. Aim : To evaluate the susceptibility profile to daptomycin among S. aureus strains isloted from patients with atopic dermatitis (AD. Another point was to correlate the results obtained by broth microdilution method and Etest, which is commonly applied in clinical setting. Material and methods : One hundred patients with the diagnosis of atopic dermatitis were microbiologically assessed for the carriage of S. aureus . Antimicrobial susceptibility tests were performed using broth-microdilution (BMD and Etests for daptomycin. Results : Staphylococcus aureus strains were isolated from the majority of our patients, either from the skin (73% or the anterior nares (75%. Six of the 100 nasal swabs (6% and 5 of the 100 skin swabs (5% were positive for methicillin-resistant Staphylococcus aureus (MRSA. A total of 81 of 148 (54.7% daptomycin non-susceptible isolates of S. aureus were identified by BMD. Only 19 of 81 were also classified as non-susceptible by Etest. Conclusions : Clinicians and microbiologists should be aware of the possibility of the emergence of daptomycin non-susceptibility (or increase in minimal inhibitory concentration during prolonged therapy and closely monitor the susceptibility of persisting isolates that might be recovered during therapy.

Inhibition of Staphylococcus aureus invasion into bovine mammary epithelial cells by contact with live Lactobacillus casei.

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Bouchard, Damien S; Rault, Lucie; Berkova, Nadia; Le Loir, Yves; Even, Sergine

2013-02-01

Staphylococcus aureus is a major pathogen that is responsible for mastitis in dairy herds. S. aureus mastitis is difficult to treat and prone to recurrence despite antibiotic treatment. The ability of S. aureus to invade bovine mammary epithelial cells (bMEC) is evoked to explain this chronicity. One sustainable alternative to treat or prevent mastitis is the use of lactic acid bacteria (LAB) as mammary probiotics. In this study, we tested the ability of Lactobacillus casei strains to prevent invasion of bMEC by two S. aureus bovine strains, RF122 and Newbould305, which reproducibly induce acute and moderate mastitis, respectively. L. casei strains affected adhesion and/or internalization of S. aureus in a strain-dependent manner. Interestingly, L. casei CIRM-BIA 667 reduced S. aureus Newbould305 and RF122 internalization by 60 to 80%, and this inhibition was confirmed for two other L. casei strains, including one isolated from bovine teat canal. The protective effect occurred without affecting bMEC morphology and viability. Once internalized, the fate of S. aureus was not affected by L. casei. It should be noted that L. casei was internalized at a low rate but survived in bMEC cells with a better efficiency than that of S. aureus RF122. Inhibition of S. aureus adhesion was maintained with heat-killed L. casei, whereas contact between live L. casei and S. aureus or bMEC was required to prevent S. aureus internalization. This first study of the antagonism of LAB toward S. aureus in a mammary context opens avenues for the development of novel control strategies against this major pathogen.

Inhibition of Staphylococcus aureus Invasion into Bovine Mammary Epithelial Cells by Contact with Live Lactobacillus casei

Science.gov (United States)

Bouchard, Damien S.; Rault, Lucie; Berkova, Nadia; Le Loir, Yves

2013-01-01

Staphylococcus aureus is a major pathogen that is responsible for mastitis in dairy herds. S. aureus mastitis is difficult to treat and prone to recurrence despite antibiotic treatment. The ability of S. aureus to invade bovine mammary epithelial cells (bMEC) is evoked to explain this chronicity. One sustainable alternative to treat or prevent mastitis is the use of lactic acid bacteria (LAB) as mammary probiotics. In this study, we tested the ability of Lactobacillus casei strains to prevent invasion of bMEC by two S. aureus bovine strains, RF122 and Newbould305, which reproducibly induce acute and moderate mastitis, respectively. L. casei strains affected adhesion and/or internalization of S. aureus in a strain-dependent manner. Interestingly, L. casei CIRM-BIA 667 reduced S. aureus Newbould305 and RF122 internalization by 60 to 80%, and this inhibition was confirmed for two other L. casei strains, including one isolated from bovine teat canal. The protective effect occurred without affecting bMEC morphology and viability. Once internalized, the fate of S. aureus was not affected by L. casei. It should be noted that L. casei was internalized at a low rate but survived in bMEC cells with a better efficiency than that of S. aureus RF122. Inhibition of S. aureus adhesion was maintained with heat-killed L. casei, whereas contact between live L. casei and S. aureus or bMEC was required to prevent S. aureus internalization. This first study of the antagonism of LAB toward S. aureus in a mammary context opens avenues for the development of novel control strategies against this major pathogen. PMID:23183972

Response of Methicillin-Resistant Staphylococcus aureus to Amicoumacin A

OpenAIRE

Lama, Amrita; Pané-Farré, Jan; Chon, Tai; Wiersma, Anna M.; Sit, Clarissa S.; Vederas, John C.; Hecker, Michael; Nakano, Michiko M.

2012-01-01

Amicoumacin A exhibits strong antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA), hence we sought to uncover its mechanism of action. Genome-wide transcriptome analysis of S. aureus COL in response to amicoumacin A showed alteration in transcription of genes specifying several cellular processes including cell envelope turnover, cross-membrane transport, virulence, metabolism, and general stress response. The most highly induced gene was lrgA, encoding an antiho...

[Change in drug resistance of Staphylococcus aureus].

Science.gov (United States)

Lin, Yan; Liu, Yan; Luo, Yan-Ping; Liu, Chang-Ting

2013-11-01

To analyze the change in drug resistance of Staphylococcus aureus (SAU) in the PLA general hospital from January 2008 to December 2012, and to provide solid evidence to support the rational use of antibiotics for clinical applications. The SAU strains isolated from clinical samples in the hospital were collected and subjected to the Kirby-Bauer disk diffusion test. The results were assessed based on the 2002 American National Committee for Clinical Laboratory Standards (NCCLS) guidelines. SAU strains were mainly isolated from sputum, urine, blood and wound excreta and distributed in penology, neurology wards, orthopedics and surgery ICU wards. Except for glycopeptide drugs, methicillin-resistant Staphylococcus aureus (MRSA) had a higher drug resistance rate than those of the other drugs and had significantly more resistance than methicillin-sensitive Staphylococcus aureus (MSSA) (P resistance, we discovered a gradual increase in drug resistance to fourteen test drugs during the last five years. Drug resistance rate of SAU stayed at a higher level over the last five years; moreover, the detection ratio of MRSA keeps rising year by year. It is crucial for physicians to use antibiotics rationally and monitor the change in drug resistance in a dynamic way.

Human Staphylococcus aureus lineages among Zoological Park residents in Greece

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E. Drougka

2015-10-01

Full Text Available Staphylococcus aureus is a part of the microbiota flora in many animal species. The clonal spread of S. aureus among animals and personnel in a Zoological Park was investigated. Samples were collected from colonized and infected sites among 32 mammals, 11 birds and eight humans. The genes mecA, mecC, lukF/lukS-PV (encoding Panton-Valentine leukocidin, PVL and tst (toxic shock syndrome toxin-1 were investigated by PCR. Clones were defined by Multilocus Sequence Typing (MLST, spa type and Pulsed-Field Gel Electrophoresis (PFGE. Seven S. aureus isolates were recovered from four animals and one from an employee. All were mecA, mecC and tst–negative, whereas, one carried the PVL genes and was isolated from an infected Squirrel monkey. Clonal analysis revealed the occurrence of seven STs, eight PFGE and five spa types including ones of human origin. Even though a variety of genotypes were identified among S. aureus strains colonizing zoo park residents, our results indicate that colonization with human lineages has indeed occurred.

Concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

Science.gov (United States)

Wang, Li Jun; Du, Xiao Qin; Nyirimigabo, Eric; Shou, Song Tao

2014-04-01

It is rare to see a concurrent infection with infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus in Tianjin, China. Until now, there is still no any single recorded case of concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

Memory Th1 Cells Are Protective in Invasive Staphylococcus aureus Infection

NARCIS (Netherlands)

A.F. Brown (Aisling F.); A.G. Murphy (Alison G.); S.J. Lalor (Stephen J.); J.M. Leech (John M.); K.M. O’Keeffe (Kate M.); M. Mac Aogáin (Micheál); D.P. O’Halloran (Dara P.); K.A. Lacey (Keenan A.); M. Tavakol (Mehri); C.H. Hearnden (Claire H.); D. Fitzgerald-Hughes (Deirdre); H. Humphreys (Hilary); J.P. Fennell (Jérôme P.); W.J.B. van Wamel (Willem); T.J. Foster (Timothy J.); J.A. Geoghegan (Joan A.); E.C. Lavelle (Ed C.); T.R. Rogers (Thomas R.); R.M. McLoughlin (Rachel M.)

2015-01-01

textabstractMechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we

Preliminary study of community-acquired Staphylococcus aureus infection in Manaus Hospital, Amazonia Region, Brazil Estudo preliminar das infeccões por Staphylococcus aureus na comunidade de um Hospital em Manaus, Região do Amazonas, Brasil

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Jesus M. Egido

2003-12-01

Full Text Available Methicillin resistant Staphylococcus aureus is considered a public health problem with a strong potential for dissemination and high rates of morbidity and mortality. In this study we describe bacteriological and epidemiological characteristics of Staphylococcus aureus in Manaus (Amazon region. During the one-year study period (2000-2001, sixteen cases of acute pyogenic multiple abscess were evaluated. Community-acquired S. aureus was identified as causative agent in 10 (62.5% patients. The strains tested with antimicrobials by discs diffusion method, exhibited a high rate of sensitivity to cephalexin (100%, erythromycin (90%. Oxacillin-susceptible Staphylococcus aureus was 90%. No isolate was resistant to Vancomycin. To our knowledge, no series of community-acquired Staphylococcus aureus in Manaus hospital has been published. Our partial results showed a high rate of antimicrobial sensitivity among community-acquired Staphylococcus aureus in the hospital of Tropical Medicine Institute of Manaus, Amazon Region.O Staphylococcus aureus resistente a meticilina é considerado como um problema na saúde publica por seu grande potencial de disseminação e altas porcentagens de morbidade e mortalidade. No estudo descrevemos as características bacteriológicas e epidemiológicas do Staphylococcus aureus na cidade de Manaus. No período de um ano (2000-2001 avaliou-se dezesseis casos de abscessos piogênicos múltiplos. Em 10 (62,5% doentes o agente causal foi identificado como Staphylococcus aureus adquirido na comunidade O estudo das bacterias isoladas frente aos diferentes antimicrobianos, seguindo o método de difusão em disco, mostrou boa sensibilidade a cefalexina (100% e eritromicina (90%. Noventa porcento dos Staphylococcus aureus isolados foram sensíveis ao oxacilina. Nenhum dos isolados mostrou ser resistente a Vancomicina. Não temos informações sobre publicações dos Staphylococcus aureus adquiridos na comunidade em hospitais de Manaus

Optimization of a Laboratory-Developed Test Utilizing Roche Analyte-Specific Reagents for Detection of Staphylococcus aureus, Methicillin-Resistant S. aureus, and Vancomycin-Resistant Enterococcus Species▿

OpenAIRE

Mehta, Maitry S.; Paule, Suzanne M.; Hacek, Donna M.; Thomson, Richard B.; Kaul, Karen L.; Peterson, Lance R.

2008-01-01

Nasal and perianal swab specimens were tested for detection of Staphylococcus aureus and vancomycin-resistant Enterococcus species (VRE) using a laboratory-developed real-time PCR test and microbiological cultures. The real-time PCR and culture results for S. aureus were similar. PCR had adequate sensitivity, but culture was more specific for the detection of VRE.

Lactobacillus rhamnosus GG Inhibits the Toxic Effects of Staphylococcus aureus on Epidermal Keratinocytes

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Mohammedsaeed, Walaa; McBain, Andrew J.; Cruickshank, Sheena M.

2014-01-01

Few studies have evaluated the potential benefits of the topical application of probiotic bacteria or material derived from them. We have investigated whether a probiotic bacterium, Lactobacillus rhamnosus GG, can inhibit Staphylococcus aureus infection of human primary keratinocytes in culture. When primary human keratinocytes were exposed to S. aureus, only 25% of the keratinocytes remained viable following 24 h of incubation. However, in the presence of 108 CFU/ml of live L. rhamnosus GG, the viability of the infected keratinocytes increased to 57% (P = 0.01). L. rhamnosus GG lysates and spent culture fluid also provided significant protection to keratinocytes, with 65% (P = 0.006) and 57% (P = 0.01) of cells, respectively, being viable following 24 h of incubation. Keratinocyte survival was significantly enhanced regardless of whether the probiotic was applied in the viable form or as cell lysates 2 h before or simultaneously with (P = 0.005) or 12 h after (P = 0.01) S. aureus infection. However, spent culture fluid was protective only if added before or simultaneously with S. aureus. With respect to mechanism, both L. rhamnosus GG lysate and spent culture fluid apparently inhibited adherence of S. aureus to keratinocytes by competitive exclusion, but only viable bacteria or the lysate could displace S. aureus (P = 0.04 and 0.01, respectively). Furthermore, growth of S. aureus was inhibited by either live bacteria or lysate but not spent culture fluid. Together, these data suggest at least two separate activities involved in the protective effects of L. rhamnosus GG against S. aureus, growth inhibition and reduction of bacterial adhesion. PMID:25015889

Staphylococcus aureus seroproteomes discriminate ruminant isolates causing mild or severe mastitis

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Le Maréchal Caroline

2011-02-01

Full Text Available Abstract Staphylococcus aureus is a major cause of mastitis in ruminants. In ewe mastitis, symptoms range from subclinical to gangrenous mastitis. S. aureus factors or host-factors contributing to the different outcomes are not completely elucidated. In this study, experimental mastitis was induced on primiparous ewes using two S. aureus strains, isolated from gangrenous (strain O11 or subclinical (strain O46 mastitis. Strains induced drastically distinct clinical symptoms when tested in ewe and mice experimental mastitis. Notably, they reproduced mild (O46 or severe (O11 mastitis in ewes. Ewe sera were used to identify staphylococcal immunoreactive proteins commonly or differentially produced during infections of variable severity and to define core and accessory seroproteomes. Such SERological Proteome Analysis (SERPA allowed the identification of 89 immunoreactive proteins, of which only 52 (58.4% were previously identified as immunogenic proteins in other staphylococcal infections. Among the 89 proteins identified, 74 appear to constitute the core seroproteome. Among the 15 remaining proteins defining the accessory seroproteome, 12 were specific for strain O11, 3 were specific for O46. Distribution of one protein specific for each mastitis severity was investigated in ten other strains isolated from subclinical or clinical mastitis. We report here for the first time the identification of staphylococcal immunogenic proteins common or specific to S. aureus strains responsible for mild or severe mastitis. These findings open avenues in S. aureus mastitis studies as some of these proteins, expressed in vivo, are likely to account for the success of S. aureus as a pathogen of the ruminant mammary gland.

Staphylococcus aureus induces IL-8 expression through its lipoproteins in the human intestinal epithelial cell, Caco-2.

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Kang, Seok-Seong; Noh, Su Young; Park, Ok-Jin; Yun, Cheol-Heui; Han, Seung Hyun

2015-09-01

Staphylococcus aureus can cause the intestinal inflammatory diseases. However, little is known about the molecular mechanism of S. aureus infection in the intestine. In the present study, we investigated whether S. aureus could stimulate human intestinal epithelial cells triggering inflammation. When the human intestinal epithelial cell-line, Caco-2, and the primary colon cells were stimulated with ethanol-inactivated S. aureus, IL-8 expression was induced in a dose-dependent manner. The inactivated S. aureus preferentially stimulated Toll-like receptor (TLR) 2 rather than TLR4. Lipoproteins, lipoteichoic acid (LTA), and peptidoglycan (PGN) are considered as potential TLR2 ligands of S. aureus. Interestingly, S aureus lipoproteins and Pam2CSK4 mimicking Gram-positive bacterial lipoproteins, but not LTA and PGN of S. aureus, significantly induced IL-8 expression in Caco-2 cells. Furthermore, lipoprotein-deficient S. aureus mutant strain failed to induce IL-8 production. Collectively, these results suggest that S. aureus stimulates the human intestinal epithelial cells to induce the chemokine IL-8 production through its lipoproteins, potentially contributing the development of intestinal inflammation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Detection of Methicillin Resistance and Various Virulence Factors in Staphylococcus aureus Strains Isolated from Nasal Carriers

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Hatice Türk Dağı

2015-06-01

Full Text Available Background: Staphylococus aureus can be found as a commensal on skin and nasal flora or it may cause local and invasive infections. S. aureus has a large number of virulence factors. Aims: To investigate the methicillin resistance and frequency of various virulence factors in S. aureus nasal isolates. Study Design: Descriptive study. Methods: Nasal samples collected from university students were cultured in media. S. aureus was identified by conventional methods and the Staphyloslide latex test (Becton Dickinson, Sparks, USA. Antibiotic susceptibility tests were conducted, and the methicillin resistance was determined. The mecA, nuc, pvl and staphylococcal toxin genes were examined by polymerase chain reaction (PCR. Results: S. aureus was isolated in 104 of 600 (17.3% nasal samples. In total, 101 (97.1% S. aureus isolates were methicillin-sensitive and the remaining 3 (2.9% were methicillin-resistant. Furthermore, all but five isolates carried at least one staphylococcal enterotoxin gene, with seg being predominant. The tst and eta genes were determined in 29 (27.9%, and 3 (2.9% isolates, respectively. None of the S. aureus isolates harbored see, etb, and pvl genes. Conclusion: A moderate rate of S. aureus carriage and low frequency of MRSA were detected in healthy students. S. aureus isolates had a high prevalence of staphylococcal enterotoxin genes and the tst gene. In this study, a large number of virulence factors were examined in S. aureus nasal isolates, and the data obtained from this study can be used for monitoring the prevalence of virulence genes in S. aureus strains isolated from nasal carriers.

Dialysis catheter-related septicaemia--focus on Staphylococcus aureus septicaemia

DEFF Research Database (Denmark)

Nielsen, J; Ladefoged, S D; Kolmos, H J

1998-01-01

BACKGROUND: Dialysis catheters are a common cause of nosocomial septicaemia in haemodialysis units usually due to staphylococci, of which Staphylococcus aureus is the most pathogenic. In this study, the epidemiology and pathogenesis of dialysis catheter-related infections were studied, and methods...... to infection were measured. After catheter insertion, all patients were screened for nasal carriage of S. aureus, and a culture was taken from the skin overlying the catheter insertion site. Once a week, cultures were taken from the insertion site and from the hub, and aerobic and anaerobic blood cultures were...... drawn from the catheter. If clinical signs of septicaemia occurred, peripheral blood cultures were also performed, when it was possible. RESULTS: The incidence of septicaemia was 49% (21/43) in patients, and 56% of all cases were caused by S. aureus. The mortality was 14% (3/21) and the incidence...

Antibiotic-mediated selection of quorum-sensing-negative Staphylococcus aureus

DEFF Research Database (Denmark)

Paulander, Wilhelm Erik Axel; Varming, Anders Nissen; Bæk, Kristoffer Torbjørn

2012-01-01

of glycopeptide resistance greater than those of other strains. We show here that agr-negative strains have a fitness advantage over agr-positive strains in the presence of sublethal concentrations of some antibiotics and that the fitness defect of agr-positive cells is caused by antibiotic-mediated expression...... expression. We demonstrate that the presence of the agr locus imposes a fitness cost on S. aureus that is mediated by the expression of RNAIII. Further, we show that exposure to sublethal levels of the antibiotics ciprofloxacin, mupirocin, and rifampin, each targeting separate cellular functions, markedly...... increases the agr-mediated fitness cost by inducing the expression of RNAIII. Thus, the extensive use of antibiotics in hospitals may explain why agr-negative variants are frequently isolated from hospital-acquired S. aureus infections but rarely found among community-acquired S. aureus strains. Importantly...

The Staphylococcus aureus α-Acetolactate Synthase ALS Confers Resistance to Nitrosative Stress

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Sandra M. Carvalho

2017-07-01

Full Text Available Staphylococcus aureus is a worldwide pathogen that colonizes the human nasal cavity and is a major cause of respiratory and cutaneous infections. In the nasal cavity, S. aureus thrives with high concentrations of nitric oxide (NO produced by the innate immune effectors and has available for growth slow-metabolizing free hexoses, such as galactose. Here, we have used deep sequencing transcriptomic analysis (RNA-Seq and 1H-NMR to uncover how S. aureus grown on galactose, a major carbon source present in the nasopharynx, survives the deleterious action of NO. We observed that, like on glucose, S. aureus withstands high concentrations of NO when using galactose. Data indicate that this resistance is, most likely, achieved through a distinct metabolism that relies on the increased production of amino acids, such as glutamate, threonine, and branched-chain amino acids (BCAAs. Moreover, we found that under NO stress the S. aureus α-acetolactate synthase (ALS enzyme, which converts pyruvate into α-acetolactate, plays an important role. ALS is proposed to prevent intracellular acidification, to promote the production of BCAAs and the activation of the TCA cycle. Additionally, ALS is shown to contribute to the successful infection of murine macrophages. Furthermore, ALS contributes to the resistance of S. aureus to beta-lactam antibiotics such as methicillin and oxacillin.

Phage Conversion for β-Lactam Antibiotic Resistance of Staphylococcus aureus from Foods.

Science.gov (United States)

Lee, Young-Duck; Park, Jong-Hyun

2016-02-01

Temperate phages have been suggested to carry virulence factors and other lysogenic conversion genes that play important roles in pathogenicity. In this study, phage TEM123 in wild-type Staphylococcus aureus from food sources was analyzed with respect to its morphology, genome sequence, and antibiotic resistance conversion ability. Phage TEM123 from a mitomycin C-induced lysate of S. aureus was isolated from foods. Morphological analysis under a transmission electron microscope revealed that it belonged to the family Siphoviridae. The genome of phage TEM123 consisted of a double-stranded DNA of 43,786 bp with a G+C content of 34.06%. A bioinformatics analysis of the phage genome identified 43 putative open reading frames (ORFs). ORF1 encoded a protein that was nearly identical to the metallo-β-lactamase enzymes that degrade β-lactam antibiotics. After transduction to S. aureus with phage TEM123, the metallo-β-lactamase gene was confirmed in the transductant by PCR and sequencing analyses. In a β-lactam antibiotic susceptibility test, the transductant was more highly resistant to β-lactam antibiotics than S. aureus S133. Phage TEM123 might play a role in the transfer of β-lactam antibiotic resistance determinants in S. aureus. Therefore, we suggest that the prophage of S. aureus with its exotoxin is a risk factor for food safety in the food chain through lateral gene transfer.

Subinhibitory concentrations of perilla oil affect the expression of secreted virulence factor genes in Staphylococcus aureus.

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Jiazhang Qiu

Full Text Available BACKGROUND: The pathogenicity of staphylococcus aureus is dependent largely upon its ability to secrete a number of virulence factors, therefore, anti-virulence strategy to combat S. aureus-mediated infections is now gaining great interest. It is widely recognized that some plant essential oils could affect the production of staphylococcal exotoxins when used at subinhibitory concentrations. Perilla [Perilla frutescens (L. Britton], a natural medicine found in eastern Asia, is primarily used as both a medicinal and culinary herb. Its essential oil (perilla oil has been previously demonstrated to be active against S. aureus. However, there are no data on the influence of perilla oil on the production of S. aureus exotoxins. METHODOLOGY/PRINCIPAL FINDINGS: A broth microdilution method was used to determine the minimum inhibitory concentrations (MICs of perilla oil against S. aureus strains. Hemolysis, tumour necrosis factor (TNF release, Western blot, and real-time RT-PCR assays were performed to evaluate the effects of subinhibitory concentrations of perilla oil on exotoxins production in S. aureus. The data presented here show that perilla oil dose-dependently decreased the production of α-toxin, enterotoxins A and B (the major staphylococcal enterotoxins, and toxic shock syndrome toxin 1 (TSST-1 in both methicillin-sensitive S. aureus (MSSA and methicillin-resistant S. aureus (MRSA. CONCLUSIONS/SIGNIFICANCE: The production of α-toxin, SEA, SEB, and TSST-1 in S. aureus was decreased by perilla oil. These data suggest that perilla oil may be useful for the treatment of S. aureus infections when used in combination with β-lactam antibiotics, which can increase exotoxins production by S. aureus at subinhibitory concentrations. Furthermore, perilla oil could be rationally applied in food systems as a novel food preservative both to inhibit the growth of S. aureus and to repress the production of exotoxins, particularly staphylococcal enterotoxins.

Preparation, characterization and efficacy of lysostaphin-chitosan gel against Staphylococcus aureus.

Science.gov (United States)

Nithya, Sai; Nimal, T R; Baranwal, Gaurav; Suresh, Maneesha K; C P, Anju; Anil Kumar, V; Gopi Mohan, C; Jayakumar, R; Biswas, Raja

2018-04-15

Lysostaphin (LST) is a bacteriocin that cleaves within the pentaglycine cross bridge of Staphylococcus aureus peptidoglycan. Previous studies have reported the high efficiency of LST even against multi drug resistant S. aureus including methicillin resistant S. aureus (MRSA). In this study, we have developed a new chitosan based hydrogel formulation of LST to exploit its anti-staphylococcal activity. The atomic interactions of LST with chitosan were studied by molecular docking studies. The rheology and the antibacterial properties of the developed LSTC gel were evaluated. The developed LST containing chitosan hydrogel (LSTC gel) was flexible, flows smoothly and remains stable at physiological temperature. The in vitro studies by agar well diffusion and ex vivo studies in porcine skin model exhibited a reduction in S. aureus survival by ∼3 Log 10 CFU/mL in the presence of LSTC gel. The cytocompatibility of the gel was tested in vitro using macrophage RAW 264.7 cell line and in vivo in Drosophila melanogaster. A gradual disruption of S. aureus biofilms with the increase of LST concentrations in the LSTC gel was observed which was confirmed by SEM analysis. We conclude that LSTC gel could be highly effectual and advantageous over antibiotics in treating staphylococcal-topical and biofilm infections. Copyright © 2018 Elsevier B.V. All rights reserved.

Staphylococcus aureus growth and enterotoxin production in different types of milk

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Bohdana Janštová, Jr.

2012-01-01

Full Text Available The aim of our study was to assess Staphylococcus aureus growth and the time of first detection of staphylococcal enterotoxins type A, B and C (SEA, SEB, SEC in different type of milk, depending on the strain and storage conditions. Raw, pasteurized, and UHT milk were inoculated with three strains of S. aureus, and growth patterns were determined by the plate method in accordance with EN ISO 6888-1. Baird-Parker agar medium was used for the detection of S. aureus and the Enzyme Linked Fluorescent Assay (ELFA used with a miniVIDAS analyzer tested the production of staphylococcal enterotoxins. The results of model experiments showed the dependence of the growth rate and subsequent production of staphylococcal enterotoxins on incubation (storage temperature, S. aureus strain, and type of milk. A significant finding was that the growth of S. aureus and production of enterotoxins in raw milk was inhibited by natural microflora, and production of enterotoxins was therefore not detected in raw milk within 102 hours of storage either at 15 °C or 22 °C. The highest risk of SEs production is associated with secondary contamination of pasteurized and UHT milk when stored at room temperature, where production was first detected after 12 hours of incubation.

Increased Susceptibility of Humanized NSG Mice to Panton-Valentine Leukocidin and Staphylococcus aureus Skin Infection.

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Ching Wen Tseng

Full Text Available Staphylococcus aureus is a leading cause of skin and soft-tissue infections worldwide. Mice are the most commonly used animals for modeling human staphylococcal infections. However a supra-physiologic S. aureus inoculum is required to establish gross murine skin pathology. Moreover, many staphylococcal factors, including Panton-Valentine leukocidin (PVL elaborated by community-associated methicillin-resistant S. aureus (CA-MRSA, exhibit selective human tropism and cannot be adequately studied in mice. To overcome these deficiencies, we investigated S. aureus infection in non-obese diabetic (NOD/severe combined immune deficiency (SCID/IL2rγnull (NSG mice engrafted with human CD34+ umbilical cord blood cells. These "humanized" NSG mice require one to two log lower inoculum to induce consistent skin lesions compared with control mice, and exhibit larger cutaneous lesions upon infection with PVL+ versus isogenic PVL- S. aureus. Neutrophils appear important for PVL pathology as adoptive transfer of human neutrophils alone to NSG mice was sufficient to induce dermonecrosis following challenge with PVL+ S. aureus but not PVL- S. aureus. PMX53, a human C5aR inhibitor, blocked PVL-induced cellular cytotoxicity in vitro and reduced the size difference of lesions induced by the PVL+ and PVL- S. aureus, but PMX53 also reduced recruitment of neutrophils and exacerbated the infection. Overall, our findings establish humanized mice as an important translational tool for the study of S. aureus infection and provide strong evidence that PVL is a human virulence factor.

Cross-Talk between Staphylococcus aureus and Other Staphylococcal Species via the agr Quorum Sensing System

DEFF Research Database (Denmark)

Canovas de la Nuez, Jaime; Baldry, Mara; Bojer, Martin S

2016-01-01

-inducing peptides (AIPs) sensed by AgrC, a two component histidine kinase. agr loci are found also in other staphylococcal species and for Staphylococcus epidermidis, the encoded AIP represses expression of agr regulated virulence genes in S. aureus. In this study we aimed to better understand the interaction...... between staphylococci and S. aureus, and show that this interaction may eventually lead to the identification of new anti-virulence candidates to target S. aureus infections. Here we show that culture supernatants of 37 out of 52 staphylococcal isolates representing 17 different species inhibit S. aureus...... suggesting that agr is an inter-species communication system. Based on these results we speculate that interactions between S. aureus and other colonizing staphylococci will significantly influence the ability of S. aureus to cause infection, and we propose that other staphylococci are potential sources...

Diversity of Staphylococcus aureus Isolates in European Wildlife.

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Stefan Monecke

Full Text Available Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST. The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963, some of which (ST2425, ST2691, ST2963 were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6. mecC-MRSA (n = 8 were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock-associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation.

Emergence in Asian Countries of Staphylococcus aureus with Reduced Susceptibility to Vancomycin

Science.gov (United States)

Song, Jae-Hoon; Hiramatsu, Keiichi; Suh, Ji Yoeun; Ko, Kwan Soo; Ito, Teruyo; Kapi, Maria; Kiem, Sungmin; Kim, Yeon-Sook; Oh, Won Sup; Peck, Kyong Ran; Lee, Nam Yong

2004-01-01

To investigate the prevalence of Staphylococcus aureus with reduced susceptibility to vancomycin among methicillin-resistant S. aureus (MRSA) strains in Asian countries, a total of 1,357 clinical isolates of MRSA collected from 12 Asian countries were screened by using brain heart infusion agar plates containing 4 mg of vancomycin per liter. The presence of strains that were heterointermediately resistant to vancomycin (hVISA) was confirmed by population analysis. Of 347 (25.6%) MRSA isolates that grew on the screening agar plates, 58 isolates (4.3%) were hVISA. hVISA strains were found in India, South Korea, Japan, the Philippines, Singapore, Thailand, and Vietnam. However, neither vancomycin-intermediate S. aureus nor vancomycin-resistant S. aureus isolates were found among MRSA isolates from Asian countries in this survey. PMID:15561884

Antibody-Based Agents in the Management of Antibiotic-Resistant Staphylococcus aureus Diseases

Science.gov (United States)

Speziale, Pietro; Rindi, Simonetta

2018-01-01

Staphylococcus aureus is a human pathogen that can cause a wide spectrum of diseases, including sepsis, pneumonia, arthritis, and endocarditis. Ineffective treatment of a number of staphylococcal infections with antibiotics is due to the development and spread of antibiotic-resistant strains following decades of antibiotic usage. This has generated renewed interest within the scientific community in alternative therapeutic agents, such as anti-S. aureus antibodies. Although the role of antibodies in the management of S. aureus diseases is controversial, the success of this pathogen in neutralizing humoral immunity clearly indicates that antibodies offer the host extensive protection. In this review, we report an update on efforts to develop antibody-based agents, particularly monoclonal antibodies, and their therapeutic potential in the passive immunization approach to the treatment and prevention of S. aureus infections. PMID:29533985

Caracterización clínica y molecular de individuos con el síndrome frágil X detectados por análisis inmunohistoquímico Clinical and molecular characterization of individuals with fragile X syndrome detected by immunohistochemical analysis

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Iván Hernández García

2004-09-01

Full Text Available Se realizó el estudio de 50 varones con retraso mental y/o autismo de etiología desconocida a fin de detectar individuos afectados con el síndrome frágil X a través del análisis inmunohistoquímico y caracterizarlos clínica y molecularmente. Entre los casos pesquisados se detectaron 3 individuos con baja expresión de la proteína relacionada con el síndrome, a quienes se les realizó la caracterización molecular. La correlación inmunohistoquímica y molecular en 2 de ellos fue positiva. La no correlación de un tercero sugiere que pudiera tratarse de una mutación puntual o una deleción del gen relacionado con la enfermedad. En otro paciente con el fenotipo neuropsicológico y físico característicos de la enfermedad se observó una expresión promedio normal baja, lo que motivó la indicación de la caracterización molecular, que resultó ser positiva. Se discuten los mecanismos genéticos y fisiopatológicos que pudieran explicar la presencia de la proteína en las células analizadas.50 males with mental retardation and/or autism of unknown etiology were studied aimed at detecting individuals affected with the Fragile X syndrome by the immunohistochemical analysis and at characterizing them from the clinical and molecular point of view. Among the screneed subjects, 3 individuals with low expression of the protein related to the syndrome were detected. Molecular characterization was performed in these cases. The immunohistochemical and molecular correlation was positive in 2 of them. The non correlation of the third suggests that it may be a punctual mutation or a deletion of the gene connected with the disease. In another patient with the neuropsychological and physical phenotype characteristic of the disease, it was observed an average normal low expression that led to the indication of the molecular characterization, which proved to be positive. The genetic and physiopathological mechanisms that could explain the presence of

The Frequency of Staphylococcus aureus Isolated from Endocervix of Infertile Women in Northwest Iran

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Akhi Mohammad Taghi

2017-01-01

Full Text Available Background Infertility is one of the major social issues. Due to the asymptomatic cervical infection associated with Staphylococcus aureus (S. aureus, the majority of patients remain undiagnosed. The present study intended to assess the frequency of S. aureus isolated from infertile women’s endocervix in northwest Iran. Materials and Methods In a descriptive cross sectional study, specimens were randomly collected during vagina examination using a sterile speculum and swabbing. After performance of antibiotic susceptibility testing, polymerase chain reaction (PCR was used to identify methicillin-resistance S. aureus (MRSA and toxic shock syndrome toxin-1 (TSST-1. Results About 26 (26% and 9 (9% women’s urogenital tracts were colonized by S. aureus and Candida spp., respectively, of which three (11.5% patients were infected with fungi and S. aureus, simultaneously. Antibiotic susceptibility results showed high activity of vancomycin and co-trimoxazole on isolates. Regarding PCR results, mecA sequences were detected in 7 (26.9% strains, whilst the tst gene encoding TSST-1 was not detected in any of clinical strains. Conclusion The prevalence of S. aureus was very high in infertile women. Therefore, it demands all patients undergoing infertility treatment to be investigated thoroughly for this type of infection.

Emergence of methicillin-resistant Staphylococcus aureus (MRSA) in different animal species

NARCIS (Netherlands)

Cuny, Christiane; Friedrich, Alexander; Kozytska, Svetlana; Layer, Franziska; Nübel, Ulrich; Ohlsen, Knut; Strommenger, Birgit; Walther, Birgit; Wieler, Lothar; Witte, Wolfgang

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in animals such as horses, pet animals and productive livestock has raised questions of a probable human origin and in more general of host specificity of S. aureus. Particular clonal lineages are obviously specific for humans (e.g.

Are Nasal Carriers of Staphylococcus aureus More Likely To Become Colonized or Infected with Methicillin-Resistant Staphylococcus aureus on Admission to a Hospital?▿

OpenAIRE

Krebes, Juliane; Al-Ghusein, Hasan; Feasey, Nick; Breathnach, Aodhan; Lindsay, Jodi A.

2010-01-01

Of 840 patients at hospital admission, 2.7% were positive for methicillin-resistant Staphylococcus aureus (MRSA) and 22.3% were positive for methicillin-susceptible S. aureus (MSSA). During the next 8 months, 4.8% of the MSSA-positive patients acquired MRSA with no lineage association. A total of 5.2% of noncarriers acquired MRSA. We find no evidence that colonized hosts are more susceptible to acquiring MRSA.

Correlación fenotipo-genotipo de variantes génicas en síndrome metabólico

OpenAIRE

Antolí Royo, Ana Cristina

2016-01-01

[ES]La importancia del Síndrome Metabólico viene dada por el aumento del riesgo cardiovascular que genera, con un aumento de la mortalidad, y por su alta prevalencia. Esto ha llevado a investigar diferentes factores genéticos que puedan estar implicados en la resistencia insulínica y la obesidad. Nuestro objetivo ha sido encontrar una asociación entre determinados polimorfismos genéticos, como son la IL-1β, IL-4, IL-6, PPAR-γ y TNF-α, y su relación con el Síndrome Metabólico (según l...

Faecal carriage of Staphylococcus aureus in the hospital and community setting: a systematic review

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Shantelle eClaassen-Weitz

2016-05-01

Full Text Available Background and rationale: Staphylococcus aureus faecal carriage has been identified as a potential source for nosocomial transmission and a risk factor for disease development. This systematic review determined the overall S. aureus (including methicillin susceptible and resistant S. aureus (MSSA and MRSA faecal carriage rates within the community and healthcare settings.Methodology: Peer-reviewed articles indexed in Medline, Scopus, Academic Search Premier, Africa-Wide Information, CINAHL, and Web of Science were identified using applicable and controlled vocabulary through to 11 November 2015. Eligible studies were ascertained by three independent reviewers. Random-effects meta-analyses of proportions were performed to determine S. aureus, MSSA and MRSA faecal carriage rates reported by eligible studies.Results: Twenty six studies were included in this review. The pooled estimates for S. aureus, MSSA and MRSA faecal carriage were 26 % (95 % confidence interval (CI: 16.8 % - 36.3 %, 86 % (95 % confidence interval (CI: 65.9 % - 97.9 % and 10 % (95 % CI: 0.7 % - 27.0 %, respectively. Faecal S. aureus carriage rates increased on average from 10 % to 65 % during the first eight weeks of life, followed by an average carriage rate of 64 % at six months and 46 % at one year of life. Genotyping techniques were employed mainly in studies conducted in developed countries and comprised largely of gel-based techniques. Six studies reported on the role of S. aureus faecal strains in diarrhoea (n = 2 and the risk for acquiring infections (n = 4. Eight of the 26 studies included in this review performed antibiotic susceptibility testing of S. aureus faecal isolates.Conclusion: This study provides evidence that screening for S. aureus faecal carriage, at least in populations at high risk, could be an effective measure for the prevention of S. aureus transmission and infection in the healthcare and community setting. More well-structured studies need to be

Prevalence and Characterization of Staphylococcus aureus Strains in the Pork Chain Supply in Chile.

Science.gov (United States)

Velasco, Valeria; Vergara, José L; Bonilla, Ana M; Muñoz, Javier; Mallea, Alejandra; Vallejos, Diego; Quezada-Aguiluz, Mario; Campos, Jorge; Rojas-García, Pedro

2018-05-01

The detection of methicillin-resistant Staphylococcus aureus (MRSA) and other emerging strains in meat-producing animals and retail meat has increased the risk of contamination of food. The aim of this study was to determine the prevalence and characterize S. aureus strains isolated from the pork chain supply in Chile. A total of 487 samples were collected: 332 samples from pigs at farms and slaughterhouses (nasal, n = 155; skin, n = 177); 85 samples from carcasses at slaughterhouses; and 70 meat samples at supermarkets and retail stores. The isolation of S. aureus was carried out by selective enrichment and culture media. Biochemical testing (API ® Staph) and PCR (detection of the nuc and mecA genes) were used to confirm S. aureus and MRSA strains. The agglutination test was used to determine the protein PBP2'. Enterotoxins (SEA, SEB, SEC, SED) were determined by agglutination test and the se genes by PCR method. Oxacillin and cefoxitin susceptibility testing were carried out using the diffusion method. The overall prevalence of S. aureus in the pork meat supply was 33.9%. A higher prevalence was detected on carcasses (56.5%), in pigs sampled at farms (40.6%) than in pigs sampled at slaughterhouses (23.3%) and in nonpackaged retail meat (43.1%) than packaged retail meat (5.3%) (p ≤ 0.05). No significant differences (p > 0.05) were found between the prevalence in pigs (28.3%) and pork meat (32.9%) and between natural pig farming (33.3%) and conventional production (52.8%). The mecA gene and the protein PBP2' were not detected in S. aureus strains. Two S. aureus strains exhibited oxacillin and cefoxitin resistance, and one S. aureus strain was resistant to cefoxitin. One S. aureus strain isolated from a meat sample was positive for enterotoxin SEB. Although the mecA gene was not detected, oxacillin-resistant and seb-producing S. aureus strains were detected, which represent a risk in the pork chain supply.

The effect of improved compliance with hygiene guidelines on transmission of Staphylococcus aureus to newborn infants: the Swedish Hygiene Intervention and Transmission of S aureus study.

Science.gov (United States)

Mernelius, Sara; Löfgren, Sture; Lindgren, Per-Eric; Blomberg, Marie; Olhager, Elisabeth; Gunnervik, Christina; Lenrick, Raymond; Thrane, Malena Tiefenthal; Isaksson, Barbro; Matussek, Andreas

2013-07-01

Newborn infants are often colonized with Staphylococcus aureus originating from health care workers (HCWs). We therefore use colonization with S aureus of newborn infants to determine the effect of an improved compliance with hygiene guidelines on bacterial transmission. Compliance with hygiene guidelines was monitored prior to (baseline) and after (follow-up) a multimodal hygiene intervention in 4 departments of obstetrics and gynecology. spa typing was used to elucidate transmission routes of S aureus collected from newborn infants, mothers, fathers, staff members, and environment. The compliance with hygiene guidelines increased significantly from baseline to follow-up. The transmission of S aureus from HCWs to infants was however not affected. Fathers had the highest colonization rates. Persistent carriage was indicated in 18% of the HCWs. The most commonly isolated spa type was t084, which was not detected in a previous study from the same geographic area. It is possible to substantially improve the compliance with hygiene guidelines, by using multimodal hygiene intervention. The improved compliance did not decrease the transmission of S aureus from sources outside the own family to newborn infants. Furthermore, we show the establishment of a new spa type (t084), which now is very common in our region. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Antiinfective therapy with a small molecule inhibitor of Staphylococcus aureus sortase.

Science.gov (United States)

Zhang, Jie; Liu, Hongchuan; Zhu, Kongkai; Gong, Shouzhe; Dramsi, Shaynoor; Wang, Ya-Ting; Li, Jiafei; Chen, Feifei; Zhang, Ruihan; Zhou, Lu; Lan, Lefu; Jiang, Hualiang; Schneewind, Olaf; Luo, Cheng; Yang, Cai-Guang

2014-09-16

Methicillin-resistant Staphylococcus aureus (MRSA) is the most frequent cause of hospital-acquired infection, which manifests as surgical site infections, bacteremia, and sepsis. Due to drug-resistance, prophylaxis of MRSA infection with antibiotics frequently fails or incites nosocomial diseases such as Clostridium difficile infection. Sortase A is a transpeptidase that anchors surface proteins in the envelope of S. aureus, and sortase mutants are unable to cause bacteremia or sepsis in mice. Here we used virtual screening and optimization of inhibitor structure to identify 3-(4-pyridinyl)-6-(2-sodiumsulfonatephenyl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole and related compounds, which block sortase activity in vitro and in vivo. Sortase inhibitors do not affect in vitro staphylococcal growth yet protect mice against lethal S. aureus bacteremia. Thus, sortase inhibitors may be useful as antiinfective therapy to prevent hospital-acquired S. aureus infection in high-risk patients without the side effects of antibiotics.

Detecting Staphylococcus aureus in milk from dairy cows using sniffer dogs.

Science.gov (United States)

Fischer-Tenhagen, C; Theby, V; Krömker, V; Heuwieser, W

2018-05-01

Fast and accurate identification of disease-causing pathogens is essential for specific antimicrobial therapy in human and veterinary medicine. In these experiments, dogs were trained to identify Staphylococcus aureus and differentiate it from other common mastitis-causing pathogens by smell. Headspaces from agar plates, inoculated raw milk samples, or field samples collected from cows with Staphylococcus aureus and other mastitis-causing pathogens were used for training and testing. The ability to learn the specific odor of Staphylococcus aureus in milk depended on the concentration of the pathogens in the training samples. Sensitivity and specificity for identifying Staphylococcus aureus were 91.3 and 97.9%, respectively, for pathogens grown on agar plates; 83.8 and 98.0% for pathogens inoculated in raw milk; and 59.0 and 93.2% for milk samples from mastitic cows. The results of these experiments underline the potential of odor detection as a diagnostic tool for pathogen diagnosis. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Antimicrobial resistant coagulase positive Staphylococcus aureus ...

African Journals Online (AJOL)

ADEYEYE

Staphylococcus aureus is an Important agent of food poisoning. In many countries, it ... humans and animals (Casey et al., 2007). ... of widespread use of antibiotics in animals for ... Laboratory Standards Institute methods (CLSI, 2010). Briefly ...

Whole-genome sequencing of bloodstream Staphylococcus aureus isolates does not distinguish bacteraemia from endocarditis

DEFF Research Database (Denmark)

Lilje, Berit; Rasmussen, Rasmus Vedby; Dahl, Anders

2017-01-01

Most Staphylococcus aureus isolates can cause invasive disease given the right circumstances, but it is unknown if some isolates are more likely to cause severe infections than others. S. aureus bloodstream isolates from 120 patients with definite infective endocarditis and 121 with S. aureus...... bacteraemia without infective endocarditis underwent whole-genome sequencing. Genome-wide association analysis was performed using a variety of bioinformatics approaches including SNP analysis, accessory genome analysis and k-mer based analysis. Core and accessory genome analyses found no association...... with either of the two clinical groups. In this study, the genome sequences of S. aureus bloodstream isolates did not discriminate between bacteraemia and infective endocarditis. Based on our study and the current literature, it is not convincing that a specific S. aureus genotype is clearly associated...

Pseudomonas aeruginosa Alters Staphylococcus aureus Sensitivity to Vancomycin in a Biofilm Model of Cystic Fibrosis Infection

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Giulia Orazi

2017-07-01

Full Text Available The airways of cystic fibrosis (CF patients have thick mucus, which fosters chronic, polymicrobial infections. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most prevalent respiratory pathogens in CF patients. In this study, we tested whether P. aeruginosa influences the susceptibility of S. aureus to frontline antibiotics used to treat CF lung infections. Using our in vitro coculture model, we observed that addition of P. aeruginosa supernatants to S. aureus biofilms grown either on epithelial cells or on plastic significantly decreased the susceptibility of S. aureus to vancomycin. Mutant analyses showed that 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO, a component of the P. aeruginosa Pseudomonas quinolone signal (PQS system, protects S. aureus from the antimicrobial activity of vancomycin. Similarly, the siderophores pyoverdine and pyochelin also contribute to the ability of P. aeruginosa to protect S. aureus from vancomycin, as did growth under anoxia. Under our experimental conditions, HQNO, P. aeruginosa supernatant, and growth under anoxia decreased S. aureus growth, likely explaining why this cell wall-targeting antibiotic is less effective. P. aeruginosa supernatant did not confer additional protection to slow-growing S. aureus small colony variants. Importantly, P. aeruginosa supernatant protects S. aureus from other inhibitors of cell wall synthesis as well as protein synthesis-targeting antibiotics in an HQNO- and siderophore-dependent manner. We propose a model whereby P. aeruginosa causes S. aureus to shift to fermentative growth when these organisms are grown in coculture, leading to reduction in S. aureus growth and decreased susceptibility to antibiotics targeting cell wall and protein synthesis.

Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches

Science.gov (United States)

Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.; Brennan, Angela K.; Isaacs, Natasha M.; Spencer, Chelsea

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA + femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci ‘excellent’ recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

El síndrome de Kallmann. Correlación fenotipo-genotípica.

OpenAIRE

García Piñero, Alfonso José

2015-01-01

El Síndrome de Kallmann (SK) es una enfermedad genética del desarrollo, que asocia un hipogonadismo hipogonadotrópico (HH) congénito con pérdida total (anosmia) o parcial (hiposmia) del olfato. La alteración olfativa es secundaria a la aplasia o hipoplasia de las estructuras olfatorias (bulbos, tractos y surcos cerebrales olfatorios). El HH se debe a la deficiencia en la hormona liberadora de gonadotropinas hipotalámica (GnRH) como resultado del fallo en la migración de las neuronas productor...

Novel structurally designed vaccine for S. aureus α-hemolysin: protection against bacteremia and pneumonia.

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Rajan P Adhikari

Full Text Available Staphylococcus aureus (S. aureus is a human pathogen associated with skin and soft tissue infections (SSTI and life threatening sepsis and pneumonia. Efforts to develop effective vaccines against S. aureus have been largely unsuccessful, in part due to the variety of virulence factors produced by this organism. S. aureus alpha-hemolysin (Hla is a pore-forming toxin expressed by most S. aureus strains and reported to play a key role in the pathogenesis of SSTI and pneumonia. Here we report a novel recombinant subunit vaccine candidate for Hla, rationally designed based on the heptameric crystal structure. This vaccine candidate, denoted AT-62aa, was tested in pneumonia and bacteremia infection models using S. aureus strain Newman and the pandemic strain USA300 (LAC. Significant protection from lethal bacteremia/sepsis and pneumonia was observed upon vaccination with AT-62aa along with a Glucopyranosyl Lipid Adjuvant-Stable Emulsion (GLA-SE that is currently in clinical trials. Passive transfer of rabbit immunoglobulin against AT-62aa (AT62-IgG protected mice against intraperitoneal and intranasal challenge with USA300 and produced significant reduction in bacterial burden in blood, spleen, kidney, and lungs. Our Hla-based vaccine is the first to be reported to reduce bacterial dissemination and to provide protection in a sepsis model of S. aureus infection. AT62-IgG and sera from vaccinated mice effectively neutralized the toxin in vitro and AT62-IgG inhibited the formation of Hla heptamers, suggesting antibody-mediated neutralization as the primary mechanism of action. This remarkable efficacy makes this Hla-based vaccine a prime candidate for inclusion in future multivalent S. aureus vaccine. Furthermore, identification of protective epitopes within AT-62aa could lead to novel immunotherapy for S. aureus infection.

Myricetin protects Galleria mellonella against Staphylococcus aureus infection and inhibits multiple virulence factors

DEFF Research Database (Denmark)

Nogueira-Silva, L; Da Hora, G. C.A.; Soares, Goncalo Teofilo Afonso Pinheiro

2017-01-01

Staphylococcus aureus is an opportunistic pathogen related to a variety of life-threatening infections but for which antimicrobial resistance is liming the treatment options. We report here that myricetin, but not its glycosylated form, can remarkably decrease the production of several S. aureus ...... in the Galleria mellonella model. The present findings reveal the potential of Myr as an alternative multi-target antivirulence candidate to control S. aureus pathogenicity....

Staphylococcus aureus Toxins and Diabetic Foot Ulcers: Role in Pathogenesis and Interest in Diagnosis

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Dunyach-Remy, Catherine; Ngba Essebe, Christelle; Sotto, Albert; Lavigne, Jean-Philippe

2016-01-01

Infection of foot ulcers is a common, often severe and costly complication in diabetes. Diabetic foot infections (DFI) are mainly polymicrobial, and Staphylococcus aureus is the most frequent pathogen isolated. The numerous virulence factors and toxins produced by S. aureus during an infection are well characterized. However, some particular features could be observed in DFI. The aim of this review is to describe the role of S. aureus in DFI and the implication of its toxins in the establishment of the infection. Studies on this issue have helped to distinguish two S. aureus populations in DFI: toxinogenic S. aureus strains (harboring exfoliatin-, EDIN-, PVL- or TSST-encoding genes) and non-toxinogenic strains. Toxinogenic strains are often present in infections with a more severe grade and systemic impact, whereas non-toxinogenic strains seem to remain localized in deep structures and bone involving diabetic foot osteomyelitis. Testing the virulence profile of bacteria seems to be a promising way to predict the behavior of S. aureus in the chronic wounds. PMID:27399775

Nigribactin, a Novel Siderophore from Vibrio nigripulchritudo, Modulates Staphylococcus aureus Virulence Gene Expression

DEFF Research Database (Denmark)

Nielsen, Anita; Månsson, Maria; Wietz, Matthias

2012-01-01

Staphylococcus aureus is a serious human pathogen that employs a number of virulence factors as part of its pathogenesis. The purpose of the present study was to explore marine bacteria as a source of compounds that modulate virulence gene expression in S. aureus. During the global marine Galathea...... 3 expedition, a strain collection was established comprising bacteria that express antimicrobial activity against Vibrio anguillarum and/or Staphylococcus aureus. Within this collection we searched colony material, culture supernatants, and cell extracts for virulence modulating activity showing......, enterobactin, failed to influence S. aureus virulence gene expression. This study shows that marine microorganisms produce compounds with potential use in therapeutic strategies targeting virulence rather than viability of human pathogens....

Staphylococcus aureus Nasal Colonization Differs among Pig Lineages and Is Associated with the Presence of Other Staphylococcal Species

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Koen M. Verstappen

2017-06-01

Full Text Available Staphylococcus aureus is a common colonizer in pigs, with methicillin-resistant S. aureus (MRSA in particular being a potential health risk to humans. To reduce the exposure to humans, the colonization in pigs should be reduced. The aim of this study was to quantitatively compare the susceptibility of pig lineages for S. aureus colonization, and if the absence of S. aureus could be associated with the presence or absence of other staphylococcal species. Nasal samples (n = 129 were obtained from seven different pig lineages in the Netherlands, France, and Germany. S. aureus and other staphylococci were enumerated from these samples by real-time (RT-PCR and culture. Associations were explored between the presence of S. aureus and other staphylococci. S. aureus was detected by RT-PCR on all farms and in samples from pigs of all lineages. Twenty-five percent of the pigs from lineage F (from two farms were colonized with S. aureus, while in all other lineages it was more than 50% (p < 0.01. Moreover, in S. aureus-positive samples from pigs of lineage F smaller amounts of S. aureus were found than in other lineages. Staphylococcus sciuri, Staphylococcus cohnii, and Staphylococcus saprophyticus were usually not found in combination with S. aureus in these samples. In conclusion: (i pigs from different genetic lineages have different susceptibilities for colonization with S. aureus. These pigs might contain a genetic factor influencing nasal colonization. (ii Colonization of S. aureus is also associated with the absence of S. sciuri, S. cohnii, or S. saprophyticus. (iii The farm environment seems to influence the presence of S. aureus in pigs.

ESCHERICHIA COLI AND STAPHYLOCOCCUS AUREUS

African Journals Online (AJOL)

DR. AMINU

ABSTRACT. The bio-effects of the ethanol extracts from the leaf and stem of Momordica charantia were studied with the view to ascertain the medical usefulness ascribed to the plant by the locals. The plant parts, stem and leaf, revealed remarkable activity against Escherichia coli and Staphlococcus aureus. The leaves ...

Antibiofilm Effect of Octenidine Hydrochloride on Staphylococcus aureus, MRSA and VRSA

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Mary Anne Roshni Amalaradjou

2014-05-01

Full Text Available Millions of indwelling devices are implanted in patients every year, and staphylococci (S. aureus, MRSA and vancomycin-resistant S. aureus (VRSA are responsible for a majority of infections associated with these devices, thereby leading to treatment failures. Once established, staphylococcal biofilms become resistant to antimicrobial treatment and host response, thereby serving as the etiological agent for recurrent infections. This study investigated the efficacy of octenidine hydrochloride (OH for inhibiting biofilm synthesis and inactivating fully-formed staphylococcal biofilm on different matrices in the presence and absence of serum protein. Polystyrene plates and stainless steel coupons inoculated with S. aureus, MRSA or VRSA were treated with OH (zero, 0.5, one, 2 mM at 37 °C for the prevention of biofilm formation. Additionally, the antibiofilm effect of OH (zero, 2.5, five, 10 mM on fully-formed staphylococcal biofilms on polystyrene plates, stainless steel coupons and urinary catheters was investigated. OH was effective in rapidly inactivating planktonic and biofilm cells of S. aureus, MRSA and VRSA on polystyrene plates, stainless steel coupons and urinary catheters in the presence and absence of serum proteins. The use of two and 10 mM OH completely inactivated S. aureus planktonic cells and biofilm (>6.0 log reduction on all matrices tested immediately upon exposure. Further, confocal imaging revealed the presence of dead cells and loss in biofilm architecture in the OH-treated samples when compared to intact live biofilm in the control. Results suggest that OH could be applied as an effective antimicrobial to control biofilms of S. aureus, MRSA and VRSA on appropriate hospital surfaces and indwelling devices.

In vitro Antibacterial Activity of Mentha Essential Oils Against Staphylococcus aureus

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Horváth P.

2017-09-01

Full Text Available Plant extracts and essential oils (EOs are characterized by their antibacterial properties against various bacterial pathogens, including staphylococci. Some strains of these bacteria are resistant against the adverse effects of the environment including antibiotics, e. g. methicillin-resistant Staphylococcus aureus (MRSA. EOs alone cannot substitute for antibiotics but their treatment may be useful to intensify and strengthen the effects of antibiotics on pathogenic staphylococci. In this work, we tested the antibacterial effects of the essential oils of Mentha species with menthol as one of the effective substances against different strains of S. aureus. Two in vitro methods were used, the qualitative disc diffusion assay and the quantitative minimal inhibitory concentration (MIC of selected essential oils. Peppermint oil from Mentha piperita, spearmint oil from Mentha spicata var. crispa and cornmint oil from Mentha arvensis were tested in this study against the various strains of Staphylococcus aureus, including methicillin resistant Staphylococcus aureus (MRSA. The oils were dissolved in DMSO (dimethyl sulfoxide and diluted at the following ratios: 1 : 1, 1 : 2, 1 : 5, and 1 : 10. Based on the results determined by the agar disc diffusion test, the highest antibacterial properties were observed in spearmint oil against S. aureus CCM 4223 at 1 : 2 ratio where the inhibition zone varied at a range of 35.67 ± 6.81 mm. We determined also the MIC of all the oils where concentrations of the oils were as follows: 1 %; 0.5 %; 0.25 %; 0.125 % and 0.0625 %. The lowest concentrations of essential oils that possessed inhibitory effects on the growth of S. aureus varied between 0.125 % and 0.25 %.

Staphylococcus aureus α-toxin modulates skin host response to viral infection.

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Bin, Lianghua; Kim, Byung Eui; Brauweiler, Anne; Goleva, Elena; Streib, Joanne; Ji, Yinduo; Schlievert, Patrick M; Leung, Donald Y M

2012-09-01

Patients with atopic dermatitis (AD) with a history of eczema herpeticum have increased staphylococcal colonization and infections. However, whether Staphylococcus aureus alters the outcome of skin viral infection has not been determined. We investigated whether S aureus toxins modulated host response to herpes simplex virus (HSV) 1 and vaccinia virus (VV) infections in normal human keratinocytes (NHKs) and in murine infection models. NHKs were treated with S aureus toxins before incubation of viruses. BALB/c mice were inoculated with S aureus 2 days before VV scarification. Viral loads of HSV-1 and VV were evaluated by using real-time PCR, a viral plaque-forming assay, and immunofluorescence staining. Small interfering RNA duplexes were used to knockdown the gene expression of the cellular receptor of α-toxin, a disintegrin and metalloprotease 10 (ADAM10). ADAM10 protein and α-toxin heptamers were detected by using Western blot assays. We demonstrate that sublytic staphylococcal α-toxin increases viral loads of HSV-1 and VV in NHKs. Furthermore, we demonstrate in vivo that the VV load is significantly greater (P skin inoculated with an α-toxin-producing S aureus strain compared with murine skin inoculated with the isogenic α-toxin-deleted strain. The viral enhancing effect of α-toxin is mediated by ADAM10 and is associated with its pore-forming property. Moreover, we demonstrate that α-toxin promotes viral entry in NHKs. The current study introduces the novel concept that staphylococcal α-toxin promotes viral skin infection and provides a mechanism by which S aureus infection might predispose the host toward disseminated viral infections. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Characterization of Staphylococcus aureus isolates from retail chicken carcasses and pet workers in Northwest Arkansas.

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Hanning, Irene; Gilmore, David; Pendleton, Sean; Fleck, Scott; Clement, Ashley; Park, Si Hong; Scott, Erin; Ricke, Steven C

2012-01-01

Staphylococcus aureus can be carried on the skin and nasal passages of humans and animals as a commensal. A case of human methicillin-resistant S. aureus infection resulting from contact with pork has been reported. Poultry carcasses are sold at retail with the skin intact, but pork and beef typically are not. Thus, the risk of methicillin-resistant S. aureus human infection from whole raw poultry carcasses may be greater than that of exposure from pork or beef. The objective of this study was to isolate and characterize S. aureus from whole retail poultry carcasses and compare the isolates to S. aureus isolates from humans. A total of 25 S. aureus isolates were collected from 222 whole poultry carcasses. The isolates were characterized phenotypically with antibiotic resistance disc diffusion assays and genotypically using multilocus sequence typing. A total of 17 S. aureus isolates obtained from healthy humans were included and characterized in the same way as the poultry isolates. Staphylococcus spp. were recovered from all poultry carcasses. Only 25 poultry carcasses (11.2%) were contaminated with S. aureus. Of these 25 isolates, 36% were resistant to at least one of the antibiotics tested and 20% were resistant to two or more antibiotics tested. However, 100% of the human isolates were resistant to at least one of the antibiotics and 94% were resistant to two or more antibiotics. The results of the multilocus sequence typing indicate that most of the isolates grouped according to source. These results indicate a low prevalence of S. aureus present in poultry, and the isolates were not phenotypically similar to human isolates. The low number of S. aureus isolates from this study indicates that chicken carcasses would appear to not be a significant source of this bacterium.

Toll-Like Receptor 2 Stimulation of Osteoblasts Mediates Staphylococcus Aureus Induced Bone Resorption and Osteoclastogenesis through Enhanced RANKL

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Kassem, Ali; Lindholm, Catharina; Lerner, Ulf H

2016-01-01

Severe Staphylococcus aureus (S. aureus) infections pose an immense threat to population health and constitute a great burden for the health care worldwide. Inter alia, S. aureus septic arthritis is a disease with high mortality and morbidity caused by destruction of the infected joints and systemic bone loss, osteoporosis. Toll-Like receptors (TLRs) are innate immune cell receptors recognizing a variety of microbial molecules and structures. S. aureus recognition via TLR2 initiates a signaling cascade resulting in production of various cytokines, but the mechanisms by which S. aureus causes rapid and excessive bone loss are still unclear. We, therefore, investigated how S. aureus regulates periosteal/endosteal osteoclast formation and bone resorption. S. aureus stimulation of neonatal mouse parietal bone induced ex vivo bone resorption and osteoclastic gene expression. This effect was associated with increased mRNA and protein expression of receptor activator of NF-kB ligand (RANKL) without significant change in osteoprotegerin (OPG) expression. Bone resorption induced by S. aureus was abolished by OPG. S. aureus increased the expression of osteoclastogenic cytokines and prostaglandins in the parietal bones but the stimulatory effect of S. aureus on bone resorption and Tnfsf11 mRNA expression was independent of these cytokines and prostaglandins. Stimulation of isolated periosteal osteoblasts with S. aureus also resulted in increased expression of Tnfsf11 mRNA, an effect lost in osteoblasts from Tlr2 knockout mice. S. aureus stimulated osteoclastogenesis in isolated periosteal cells without affecting RANKL-stimulated resorption. In contrast, S. aureus inhibited RANKL-induced osteoclast formation in bone marrow macrophages. These data show that S. aureus enhances bone resorption and periosteal osteoclast formation by increasing osteoblast RANKL production through TLR2. Our study indicates the importance of using different in vitro approaches for studies of how S

Methicillin resistant S. aureus in human and bovine mastitis.

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Holmes, Mark A; Zadoks, Ruth N

2011-12-01

Staphylococcus aureus is a ubiquitous organism that causes a variety of diseases including mastitis in cattle and humans. High-level resistance of S. aureus to β-lactams conferred by a mecA gene encoding a modified penicillin binding protein (PBP2a) was first observed in the early 1960's. These methicillin resistant S. aureus (MRSA) have been responsible for both hospital acquired infections (HA-MRSA) and, more recently, community acquired MRSA (CA-MRSA). A small number of human MRSA mastitis cases and outbreaks in maternity or neonatal units have been reported which are generally the result of CA-MRSA. The establishment of the sequence type 398 (ST398) in farm animals, primarily pigs, in the early 2000's has provided a reservoir of infection for humans and dairy cattle, particularly in continental Europe, described as livestock-associated MRSA (LA-MRSA). Prior to the emergence of ST398 there were sporadic reports of MRSA in bovine milk and cases of mastitis, often caused by strains from human associated lineages. Subsequently, there have been several reports describing bovine udder infections caused by ST-398 MRSA. Recently, another group of LA-MRSA strains was discovered in humans and dairy cattle in Europe. This group carries a divergent mecA gene and includes a number of S. aureus lineages (CC130, ST425, and CC1943) that were hitherto thought to be bovine-specific but are now also found as carriage or clinical isolates in humans. The emergence of MRSA in dairy cattle may be associated with contact with other host species, as in the case of ST398, or with the exchange of genetic material between S. aureus and coagulase negative Staphylococcus species, which are the most common species associated with bovine intramammary infections and commonly carry antimicrobial resistance determinants.

Dual Roles of FmtA in Staphylococcus aureus Cell Wall Biosynthesis and Autolysis

Science.gov (United States)

Qamar, Aneela

2012-01-01

The fmtA gene is a member of the Staphylococcus aureus core cell wall stimulon. The FmtA protein interacts with β-lactams through formation of covalent species. Here, we show that FmtA has weak d-Ala-d-Ala-carboxypeptidase activity and is capable of covalently incorporating C14-Gly into cell walls. The fluorescence microscopy study showed that the protein is localized to the cell division septum. Furthermore, we show that wall teichoic acids interact specifically with FmtA and mediate recruitment of FmtA to the S. aureus cell wall. Subjection of S. aureus to FmtA concentrations of 0.1 μM or less induces autolysis and biofilm production. This effect requires the presence of wall teichoic acids. At FmtA concentrations greater than 0.2 μM, autolysis and biofilm formation in S. aureus are repressed and growth is enhanced. Our findings indicate dual roles of FmtA in S. aureus growth, whereby at low concentrations, FmtA may modulate the activity of the major autolysin (AtlA) of S. aureus and, at high concentrations, may participate in synthesis of cell wall peptidoglycan. These two roles of FmtA may reflect dual functions of FmtA in the absence and presence of cell wall stress, respectively. PMID:22564846

Neutrophil depletion causes a fatal defect in murine pulmonary Staphylococcus aureus clearance.

Science.gov (United States)

Robertson, Charles M; Perrone, Erin E; McConnell, Kevin W; Dunne, W Michael; Boody, Barrett; Brahmbhatt, Tejal; Diacovo, M Julia; Van Rooijen, Nico; Hogue, Lisa A; Cannon, Carolyn L; Buchman, Timothy G; Hotchkiss, Richard S; Coopersmith, Craig M

2008-12-01

Staphylococcus aureus is the most common cause of healthcare-associated pneumonia. Despite the significant morbidity and mortality associated with the disease, animal models of S. aureus pneumonia are rare. We examined the pathogenicity of four different strains of S. aureus (both methicillin-sensitive and -resistant as well as Panton-Valentine leukocidin-positive and -negative) in four strains of immunocompetent inbred and outbred mice (FVB/N, C57Bl/6, BALB/c, ND4; n = 148). The immunological basis for the development of murine S. aureus pneumonia was then determined by selectively depleting neutrophils, lymphocytes, or pulmonary macrophages prior to the onset of infection. An additional cohort of animals was rendered immunosuppressed by induction of abdominal sepsis via cecal ligation and puncture 2, 4, or 7 d prior to the onset of pneumonia. Nearly all immunocompetent mice survived, regardless of which strain of S. aureus was used or which strain of mouse was infected. Among animals with immune depletion or prior immunosuppression, survival was decreased only following neutrophil depletion (26% versus 90% alive at 7 d, P < 0.0001). Compared to immunocompetent animals, neutrophil-depleted mice with S. aureus pneumonia had delayed pulmonary bacterial clearance at 16 and 40 h but had no difference in levels of bacteremia. Neutrophil-depleted mice also had elevated levels of pulmonary monocyte chemotactic protein-1 (822 pg/mL versus 150 pg/mL, P < 0.05). In contrast, pulmonary histological appearance was similar in both groups as was dry/wet lung weight. These results suggest that neutrophils play a critical role in the host response to S. aureus pneumonia, and the survival differences observed in neutrophil-depleted mice are associated with alterations in bacterial clearance and pulmonary cytokine response.

Screening of virulence genes in Staphylococcus aureus isolates from rabbits

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David Viana Martín

2015-09-01

Full Text Available Staphylococcus aureus is a versatile pathogen able to cause disease in both humans and animals. In rabbits, this bacterium infects animals of different ages, producing several purulent lesions. The ability of S. aureus to cause disease depends on a combination of virulence factors. The aim of this study was therefore to investigate the distribution of bacterial virulence determinants in 69 S. aureus isolates from rabbits. Some virulence factors (7 adhesins, 1 toxin and 1 protease were positive in all rabbit S. aureus isolates analysed, while others (1 adhesin and 10 toxins were always negative. The remaining virulence factors were more variable among isolates. An association between genotype and the different profiles of virulence factors was observed, but not with the type of lesion (P<0.05. One strain of each genotype was further analysed by multilocus sequence typing, generating ST121, ST96 and ST2951, determining a greater number of enterotoxins in ST121 isolates compared to ST96 and ST2951 isolates, which could justify the different pathogenicity between strains. 

Formation of ring marks in stocked tilapia juveniles (Oreochromis aureus/O. niloticus (Perciformes: Cichlidae

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Ana L Ibañez

2007-12-01

Full Text Available Lake Metztitlán was dried up completely in the spring of 1998 and refilled in August of that year. In the period September-November, two cohorts of 1.6 million juveniles of a tilapia hybrid were stocked (Oreochromis aureus/O. niloticus, and monitored every month for one year. Since the date of birth of these juveniles was known, the analyses focused on whether the ring marks of the scales, sagittae and opercula or the circuli of the scales could be used to age them. The ring marks of the scales and opercula showed great variability, and the sagittae had a significant relationship with length, but it is unclear if at least the first ring mark could be formed at the hatchery and reflect changes in diet and/or tank movements in the fish farm. The circuli had a continuous regular behavior, with a formation rate of 10.38±0.93 and 11.38±0.95 circuli/month for the first and second cohorts, respectively. This proportion was maintained during the study period, and could be of help to calculate an approximate age of juveniles, especially in stocked fish that show multiple ring marks because of manipulation in fish farms and stocking events. Rev. Biol. Trop. 55 (3-4: 1005-1013. Epub 2007 December, 28.El lago de Metztitlán se secó completamente en la primavera de 1998, inundándose nuevamente en agosto del mismo año para ser repoblado entre septiembre y noviembre con 1.6 millones de jóvenes de un híbrido de tilapia (Oreochromis aureus/O. niloticus en dos periodos. Ambas cohortes fueron monitoreadas mensualmente durante un año. Debido a que la fecha de nacimiento era conocida, el objetivo del estudio fue evaluar si las marcas anulares de las escamas, las sagittae y los opérculos, o los circuli de las escamas pueden usarse para estimar la edad. Los anillos de las escamas y opérculos mostraron gran variabilidad, mientras que las de las sagittae se relacionaron significativamente con la longitud, sin embargo no quedó claro si al menos el primer

Kaempferol Inhibits the Primary Attachment Phase of Biofilm Formation in Staphylococcus aureus.

Science.gov (United States)

Ming, Di; Wang, Dacheng; Cao, Fengjiao; Xiang, Hua; Mu, Dan; Cao, Junjie; Li, Bangbang; Zhong, Ling; Dong, Xiaoyun; Zhong, Xiaobo; Wang, Lin; Wang, Tiedong

2017-01-01

The ability to form biofilms on surfaces makes Staphylococcus aureus the main pathogenic factor in implanted medical device infections. The aim of this study was to discover a biofilm inhibitor distinct from the antibiotics used to prevent infections resulting from S. aureus biofilms. Here, we describe kaempferol, a small molecule with anti-biofilm activity that specifically inhibited the formation of S. aureus biofilms. Crystal violet (CV) staining and fluorescence microscopy clearly showed that 64 μg/ml kaempferol inhibited biofilm formation by 80%. Meanwhile, the minimum inhibitory concentration (MIC) and growth curve results indicated that kaempferol had no antibacterial activity against the tested bacterial strain. Kaempferol inhibited the primary attachment phase of biofilm formation, as determined by a fibrinogen-binding assay. Moreover, a fluorescence resonance energy transfer (FRET) assay and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analyses revealed that kaempferol reduced the activity of S. aureus sortaseA (SrtA) and the expression of adhesion-related genes. Based on these results, kaempferol provides a starting point for the development of novel anti-biofilm drugs, which may decrease the risk of bacterial drug resistance, to prevent S. aureus biofilm-related infections.

Inhibitory effects of flavonoids on biofilm formation by Staphylococcus aureus that overexpresses efflux protein genes.

Science.gov (United States)

Lopes, Laênia Angélica Andrade; Dos Santos Rodrigues, Jéssica Bezerra; Magnani, Marciane; de Souza, Evandro Leite; de Siqueira-Júnior, José P

2017-06-01

This study evaluated the efficacy of glycone (myricitrin, hesperidin and phloridzin) and aglycone flavonoids (myricetin, hesperetin and phloretin) in inhibiting biofilm formation by Staphylococcus aureus RN4220 and S. aureus SA1199B that overexpress the msrA and norA efflux protein genes, respectively. The minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC 50 - defined as the lowest concentration that resulted in ≥50% inhibition of biofilm formation) of flavonoids were determined using microdilution in broth procedures. The flavonoids showed MIC >1024 μg/mL against S. aureus RN4220 and S. aureus SA1199B; however, these compounds at lower concentrations (1-256 μg/mL) showed inhibitory effects on biofilm formation by these strains. Aglycone flavonoids showed lower MBIC 50 values than their respective glycone forms. The lowest MBIC 50 values (1 and 4 μg/mL) were observed against S. aureus RN4220. Myricetin, hesperetin and phloretin exhibited biofilm formation inhibition >70% for S. aureus RN4220, and lower biofilm formation inhibition against S. aureus SA1199B. These results indicate that sub-MICs of the tested flavonoids inhibit biofilm formation by S. aureus strains that overexpress efflux protein genes. These effects are more strongly established by aglycone flavonoids. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hospitalizations and Deaths Caused by Methicillin-Resistant Staphylococcus aureus, United States, 1999?2005

OpenAIRE

Klein, Eili; Smith, David L.; Laxminarayan, Ramanan

2007-01-01

Hospital-acquired infections with Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA) infections, are a major cause of illness and death and impose serious economic costs on patients and hospitals. However, the recent magnitude and trend of these infections have not been reported. We used national hospitalization and resistance data to estimate the annual number of hospitalizations and deaths associated with S. aureus and MRSA from 1999 through 2005. During this period, t...

Selective inhibition of Biotin Protein Ligase from Staphylococcus aureus*

Science.gov (United States)

Soares da Costa, Tatiana P.; Tieu, William; Yap, Min Y.; Pendini, Nicole R.; Polyak, Steven W.; Sejer Pedersen, Daniel; Morona, Renato; Turnidge, John D.; Wallace, John C.; Wilce, Matthew C. J.; Booker, Grant W.; Abell, Andrew D.

2012-01-01

There is a well documented need to replenish the antibiotic pipeline with new agents to combat the rise of drug resistant bacteria. One strategy to combat resistance is to discover new chemical classes immune to current resistance mechanisms that inhibit essential metabolic enzymes. Many of the obvious drug targets that have no homologous isozyme in the human host have now been investigated. Bacterial drug targets that have a closely related human homologue represent a new frontier in antibiotic discovery. However, to avoid potential toxicity to the host, these inhibitors must have very high selectivity for the bacterial enzyme over the human homolog. We have demonstrated that the essential enzyme biotin protein ligase (BPL) from the clinically important pathogen Staphylococcus aureus could be selectively inhibited. Linking biotin to adenosine via a 1,2,3 triazole yielded the first BPL inhibitor selective for S. aureus BPL over the human equivalent. The synthesis of new biotin 1,2,3-triazole analogues using click chemistry yielded our most potent structure (Ki 90 nm) with a >1100-fold selectivity for the S. aureus BPL over the human homologue. X-ray crystallography confirmed the mechanism of inhibitor binding. Importantly, the inhibitor showed cytotoxicity against S. aureus but not cultured mammalian cells. The biotin 1,2,3-triazole provides a novel pharmacophore for future medicinal chemistry programs to develop this new antibiotic class. PMID:22437830

Selective inhibition of biotin protein ligase from Staphylococcus aureus.

Science.gov (United States)

Soares da Costa, Tatiana P; Tieu, William; Yap, Min Y; Pendini, Nicole R; Polyak, Steven W; Sejer Pedersen, Daniel; Morona, Renato; Turnidge, John D; Wallace, John C; Wilce, Matthew C J; Booker, Grant W; Abell, Andrew D

2012-05-18

There is a well documented need to replenish the antibiotic pipeline with new agents to combat the rise of drug resistant bacteria. One strategy to combat resistance is to discover new chemical classes immune to current resistance mechanisms that inhibit essential metabolic enzymes. Many of the obvious drug targets that have no homologous isozyme in the human host have now been investigated. Bacterial drug targets that have a closely related human homologue represent a new frontier in antibiotic discovery. However, to avoid potential toxicity to the host, these inhibitors must have very high selectivity for the bacterial enzyme over the human homolog. We have demonstrated that the essential enzyme biotin protein ligase (BPL) from the clinically important pathogen Staphylococcus aureus could be selectively inhibited. Linking biotin to adenosine via a 1,2,3 triazole yielded the first BPL inhibitor selective for S. aureus BPL over the human equivalent. The synthesis of new biotin 1,2,3-triazole analogues using click chemistry yielded our most potent structure (K(i) 90 nM) with a >1100-fold selectivity for the S. aureus BPL over the human homologue. X-ray crystallography confirmed the mechanism of inhibitor binding. Importantly, the inhibitor showed cytotoxicity against S. aureus but not cultured mammalian cells. The biotin 1,2,3-triazole provides a novel pharmacophore for future medicinal chemistry programs to develop this new antibiotic class.

Purification and biochemical characterization of Mur ligases from Staphylococcus aureus.

Science.gov (United States)

Patin, Delphine; Boniface, Audrey; Kovač, Andreja; Hervé, Mireille; Dementin, Sébastien; Barreteau, Hélène; Mengin-Lecreulx, Dominique; Blanot, Didier

2010-12-01

The Mur ligases (MurC, MurD, MurE and MurF) catalyze the stepwise synthesis of the UDP-N-acetylmuramoyl-pentapeptide precursor of peptidoglycan. The murC, murD, murE and murF genes from Staphylococcus aureus, a major pathogen, were cloned and the corresponding proteins were overproduced in Escherichia coli and purified as His(6)-tagged forms. Their biochemical properties were investigated and compared to those of the E. coli enzymes. Staphylococcal MurC accepted L-Ala, L-Ser and Gly as substrates, as the E. coli enzyme does, with a strong preference for L-Ala. S. aureus MurE was very specific for L-lysine and in particular did not accept meso-diaminopimelic acid as a substrate. This mirrors the E. coli MurE specificity, for which meso-diaminopimelic acid is the preferred substrate and L-lysine a very poor one. S. aureus MurF appeared less specific and accepted both forms (L-lysine and meso-diaminopimelic acid) of UDP-MurNAc-tripeptide, as the E. coli MurF does. The inverse and strict substrate specificities of the two MurE orthologues is thus responsible for the presence of exclusively meso-diaminopimelic acid and L-lysine at the third position of the peptide in the peptidoglycans of E. coli and S. aureus, respectively. The specific activities of the four Mur ligases were also determined in crude extracts of S. aureus and compared to cell requirements for peptidoglycan biosynthesis. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Transmission of Staphylococcus aureus from maternity unit staff members to newborns disclosed through spa typing.

Science.gov (United States)

Matussek, Andreas; Taipalensuu, Jan; Einemo, Ing-Marie; Tiefenthal, Malena; Löfgren, Sture

2007-03-01

We observed previously that newborn infants are colonized with Staphylococcus aureus, even if their mothers do not carry S aureus. This observation indicated a cross colonization, and, thus, a risk for nosocomial infection, although the infants are roomed in with their mothers. The S aureus colonization of infants, their parents, and staff members was measured at 3 maternity units. Possible transmission routes were determined using spa typing of S aureus isolates. Infants had the highest S aureus carriage (45%) compared with fathers (39%), mothers (27%), and staff members (27%). In 13 out of 44 colonized infants, transmission from staff members was indicated. This transmission was more frequent than was transmission from their own parents (11 cases), and occurred even in cases when parents were colonized with S aureus of other spa types. We confirm a high level of transmission of S aureus from staff members to infants, indicating a risk for patient safety, which necessitates continuing work with implementing scientific evidence for infection control. The spa typing is a rapid and valuable epidemiological tool, and it can be used in improving hospital hygiene control programs.

The Collagen-Binding Adhesin Is a Virulence Factor in Staphylococcus aureus Keratitis

Science.gov (United States)

Rhem, Marcus N.; Lech, Elizabeth M.; Patti, Joseph M.; McDevitt, Damien; Höök, Magnus; Jones, Dan B.; Wilhelmus, Kirk R.

2000-01-01

A collagen-binding strain of Staphylococcus aureus produced suppurative inflammation in a rabbit model of soft contact lens-associated bacterial keratitis more often than its collagen-binding-negative isogenic mutant. Reintroduction of the cna gene on a multicopy plasmid into the mutant helped it regain its corneal adherence and infectivity. The topical application of a collagen-binding peptide before bacterial challenge decreased S. aureus adherence to deepithelialized corneas. These data suggest that the collagen-binding adhesin is involved in the pathogenesis of S. aureus infection of the cornea. PMID:10816547

Scintigraphic imaging of Staphylococcus aureus infection using 99mTc radiolabeled aptamers.

Science.gov (United States)

Santos, Sara Roberta Dos; de Sousa Lacerda, Camila Maria; Ferreira, Iêda Mendes; de Barros, André Luís Branco; Fernandes, Simone Odília; Cardoso, Valbert Nascimento; de Andrade, Antero Silva Ribeiro

2017-10-01

Staphylococcus aureus is a specie of great medical importance associated with many infections as bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device related infections. Early identification of infectious foci is crucial for successful treatment. Scintigraphy could contribute to this purpose since specific radiotracers were available. Aptamers due to their high specificity have great potential for radiopharmaceuticals development. In the present study scintigraphic images of S. aureus infectious foci were obtained using specific S. aureus aptamers radiolabeled with 99m Tc. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inhibitory effect of totarol on exotoxin proteins hemolysin and enterotoxins secreted by Staphylococcus aureus.

Science.gov (United States)

Shi, Ce; Zhao, Xingchen; Li, Wenli; Meng, Rizeng; Liu, Zonghui; Liu, Mingyuan; Guo, Na; Yu, Lu

2015-10-01

Staphylococcus aureus (S. aureus) causes a wide variety of infections, which are of major concern worldwide. S. aureus produces multiple virulence factors, resulting in food infection and poisoning. These virulence factors include hyaluronidases, proteases, coagulases, lipases, deoxyribonucleases and enterotoxins. Among the extracellular proteins produced by S. aureus that contribute to pathogenicity, the exotoxins α-hemolysin, staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB) are thought to be of major significance. Totarol, a plant extract, has been revealed to inhibit the proliferation of several pathogens effectively. However, there are no reports on the effects of totarol on the production of α-hemolysin, SEA or SEB secreted by S. aureus. The aim of this study was to evaluate the effects of totarol on these three exotoxins. Hemolysis assay, western blotting and real-time reverse transcriptase-PCR assay were performed to identify the influence of graded subinhibitory concentrations of totarol on the production of α-hemolysin and the two major enterotoxins, SEA and SEB, by S. aureus in a dose-dependent manner. Moreover, an enzyme linked immunosorbent assay showed that the TNF-α production of RAW264.7 cells stimulated by S. aureus supernatants was inhibited by subinhibitory concentrations of totarol. Form the data, we propose that totarol could potentially be used as a promising natural compound in the food and pharmaceutical industries.

Mastitis Bovina: Resistencia a antibióticos de cepas de Staphylococcus aureus asiladas de leche (Bovine Mastitis: Antimicrobial resistance of Staphylococcus aureus strains isolated from milk)

OpenAIRE

Pellegrino, MS; Frola, ID; Odierno, LM; Bogni, CI

2011-01-01

ResumenLa mastitis bovina es considerada la enfermedad infecciosa del ganado lechero de mayor impacto económico mundial, siendo Staphylococcus aureus el principal agente patógeno en muchos países.SummaryBovine mastitis is a frequent cause of economic loss in worldwide dairy herds, being Staphylococcus aureus the main etiological agent in many countries.

Staphylococcus aureus ST398 gene expression profiling during ex vivo colonization of porcine nasal epithelium

NARCIS (Netherlands)

Tulinski, P.; Duim, B.; Wittink, F.R.; Jonker, M.J.; Breit, T.M.; van Putten, J.P.; Wagenaar, J.A.; Fluit, A.C.

2014-01-01

Background: Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig

Staphylococcus aureus ST398 gene expression profiling during ex vivo colonization of porcine nasal epithelium

NARCIS (Netherlands)

Tulinski, P.; Duim, B.; Wittink, F.R.; Jonker, M.J.; Breit, T.M.; Van Putten, J.P.; Wagenaar, J.A.; Fluit, A.C.

2014-01-01

Background Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig

Staphylococcus aureus ST398 gene expression profiling during ex vivo colonization of porcine nasal epithelium

NARCIS (Netherlands)

Tulinski, Pawel; Duim, Birgitta; Wittink, Floyd R; Jonker, Martijs J; Breit, Timo M; van Putten, Jos P; Wagenaar, Jaap A; Fluit, Ad C

2014-01-01

BACKGROUND: Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig

Caracterización biológica de variantes de placa de la cepa vacunal 17d contra la fiebre amarilla

OpenAIRE

Rojas, María; Camacho, Marcela; Grosso, María

2009-01-01

La vacuna colombiana 17D, contiene por lo menos cuatro fenotipos, denominados pequeño (0.3 – 1.2 mm), mediano (1.3 – 2.1 mm), grande (2.2 – 3.0 mm) y extragrande (>3.1 mm). La composición y distribución porcentual de esos fenotipos, varió entre lotes y entre ampolletas de un mismo lote. Cada variante fue clonada por dilución de la vacuna y su efecto virulento fue analizado en ratones; el fenotipo de placa pequeño estuvo ligeramente sub representado en los lotes analizados y mostró una viru...

preescolares desnutridos con madres con obesidad y sin obesidad

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Viridiana Vanessa Conzuelo-González

2009-01-01

Full Text Available El primer objetivo fue conocer cuántos menores de cinco años con diferentes grados de desnutrición tienen una madre con sobrepeso/obesidad/ en una comunidad indígena que vive en extrema pobreza y bajo condiciones de migración masculina internacional. El segundo fue comparar tres variables socionutricionales (ingreso familiar, educación de la madre y adecuación nutrimental de la dieta diaria entre estos hogares y los hogares con desnutrición infantil y madres sin obesidad. Se realizó un estudio transversal (2006-2007, en la comunidad mazahua de San Francisco Tepeolulco, Municipio de Temascalcingo; que incluyó a 85 hogares integrados por preescolares con desnutrición inscritos al programa Oportunidades. Se determinó el estado nutrición de los preescolares con indicadores antropométricos y se obtuvo el IMC de las madres de estos infantes. Se aplicó una encuesta socionutricional, incluida el recordatorio de 24 horas, y complementado con la observación participante (cualitativa. Se encontró que 83% de las madres mazahuas presentaron sobrepeso u obesidad. El estado de nutrición de los preescolares con madres con obesidad presentó un porcentaje mayor de desnutrición (76%. En la variable género, se encontró que 54% de los niños con madres con obesidad tenía baja talla. Al relacionar el nivel educativo de la madre, esta variable resultó ser estadísticamente significativa (p=0.015, donde el analfabetismo está más relacionado con la desnutrición infantil que tienen madres de bajo y/o peso normal. La elevada prevalencia de hogares conformados con preescolares con desnutrición y madres con obesidad, es un síntoma más de la pobreza en zonas indígenas en México, con bajo índice de desarrollo humano.

Staphylococcus aureus Nasal Colonization Differs among Pig Lineages and Is Associated with the Presence of Other Staphylococcal Species.

Science.gov (United States)

Verstappen, Koen M; Willems, Eveline; Fluit, Ad C; Duim, Birgitta; Martens, Marc; Wagenaar, Jaap A

2017-01-01

Staphylococcus aureus is a common colonizer in pigs, with methicillin-resistant S. aureus (MRSA) in particular being a potential health risk to humans. To reduce the exposure to humans, the colonization in pigs should be reduced. The aim of this study was to quantitatively compare the susceptibility of pig lineages for S. aureus colonization, and if the absence of S. aureus could be associated with the presence or absence of other staphylococcal species. Nasal samples ( n  = 129) were obtained from seven different pig lineages in the Netherlands, France, and Germany. S. aureus and other staphylococci were enumerated from these samples by real-time (RT)-PCR and culture. Associations were explored between the presence of S. aureus and other staphylococci. S. aureus was detected by RT-PCR on all farms and in samples from pigs of all lineages. Twenty-five percent of the pigs from lineage F (from two farms) were colonized with S. aureus , while in all other lineages it was more than 50% ( p  Staphylococcus sciuri, Staphylococcus cohnii , and Staphylococcus saprophyticus were usually not found in combination with S. aureus in these samples. (i) pigs from different genetic lineages have different susceptibilities for colonization with S. aureus . These pigs might contain a genetic factor influencing nasal colonization. (ii) Colonization of S. aureus is also associated with the absence of S. sciuri, S. cohnii , or S. saprophyticus . (iii) The farm environment seems to influence the presence of S. aureus in pigs.

Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer

NARCIS (Netherlands)

Amissah, Nana Ama; Chlebowicz, Monika A.; Ablordey, Anthony; Sabat, Artur J.; Tetteh, Caitlin S.; Prah, Isaac; van der Werf, Tjip S.; Friedrich, Alex W.; van Dijl, Jan Maarten; Rossen, John W.; Stienstra, Ymkje

Background Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. Methodology This study investigated possible patient-to-patient transmission events of S. aureus during

Antimicrobial susceptibility of photodynamic therapy (UVA/riboflavin against Staphylococcus aureus Suscetibilidade antimicrobiana da terapia fotodinâmica (UVA/riboflavina contra Staphylococcus aureus

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Renata Tiemi Kashiwabuchi

2012-12-01

Full Text Available PURPOSE: To assess S. aureus in vitro viability after the exposure to ultraviolet light A (UVA and riboflavin (B2. METHODS: Samples of S. aureus in 96 well plates (in triplicate were exposed to riboflavin (B2 and ultraviolet light A (365 nm wavelength at a power density of 3 mW/cm², 8 mm spot diameter, for 30 minutes. Control groups were prepared as well in triplicate: blank control, ultraviolet light A only, riboflavin only and dead bacteria Control. The bacterial viability was measured using fluorescent microscopy. In order to investigate the occurrence of "viable but non-culturable" microorganisms after treatment, the cell viability was also investigated by plate culture procedure onto a broth medium. Statistical analysis was performed using the triplicate values from each experimental condition. RESULTS: No difference was observed among the treatment group and the control samples (p=1. CONCLUSION: The combination of riboflavin 0.1% and ultraviolet light A at 365 nm did not exhibit antimicrobial activity against oxacillin susceptible S. aureus.OBJETIVO: Avaliar a viabilidade celular de S. aureus in vitro após a exposição de riboflavina (B2 e luz ultravioleta A (UVA. MÉTODOS: Amostras de S. aureus colocadas em uma placa de 96 poços (em triplicata foram expostas a riboflavina 0,1% (B2 e luz ultravioleta (comprimento de onda de 365 nm poder de 3 mW/cm², 8 mm de diâmetro, por 30 minutos. Grupos controles foram também preparados em triplicata: controle branco, somente luz ultravioleta A, somente riboflavina e controle morto. A viabilidade bacteriana foi analisada usando microscópio de fluorescência. Para investigar a ocorrência de micro-organismos "viáveis porem não cultiváveis" a viabilidade celular foi avaliada utilizando-se placas de meio de cultivo bacteriano. Analise estatística foi realizada utilizando-se os valores obtidos em triplicata de cada grupo experimental. RESULTADOS: Nenhuma diferença foi observada entre o grupo

Sensitivity test of staphylococcus aureus against extract tinospora crispa

OpenAIRE

Lucia Ratna Winata Muslimin

2017-01-01

A bacterium such as Staphylococcus aureus ( S.aureus) produces a kind of toxic protein which can disrupt intestinal wall. Livestock reacts to these toxins by pumping lots of water into the intestine in order to rinse or flush these toxins. As a result, the livestock have diarrhea as a body response to remove the toxin in the digestive system. In the presence of these problems, farmers take a measure such as using antibiotics freely. Among farmers, antibiotics are often used freely without kn...

Infecções intramamárias causadas por Staphylococcus aureus e suas implicações em paúde pública Staphylococcus aureus intramammary infections and its implications in public health

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Helena Fagundes

2004-08-01

Full Text Available Neste trabalho, são apresentados os principais problemas decorrentes das infecções intramamárias (mastites causadas por Staphylococcus aureus e as conseqüências para a saúde humana da veiculação de suas toxinas através do leite. o S. aureus destaca-se como um dos microorganismos mais importantes que podem ser transmitidos através dos alimentos. Assim, discute-se a possibilidade de veiculação de gastroenterite estafilocócica, não somente através do consumo de leite cru contaminado, mas também de leite tratado termicamente ou de derivados lácteos contendo enterotoxinas termoestáveis. São apresentados alguns aspectos relacionados ao potencial toxigênico das cepas de S. aureus, bem como as principais características das enterotoxinas estafilocócicas. Considerando que o S. aureus é um dos agentes de mastite mais freqüentemente observados, apresentam-se as principais medidas de controle de infecções estafilocócicas em rebanhos leiteiros, com vistas à prevenção da ocorrência de toxinas no leite de consumo.This article presents the main problems derived from the mammary infections (mastitis caused by Staphylococcus aureus, and the consequences of the presence of its toxins in milk for human health. S. aureus is one of the most important microorganisms that can be transmitted through the food products. Hence, the possibility of transmission of stafilococal gastroenteritis by consumption of raw milk and heat-treated milk, containing heat-resistant enterotoxins, is discussed. Some aspects regarding the toxigenic potential of S. aureus strains and the main characteristics of stafilococal entorotoxins are presented. Taking into account that S. aureus is also one of the most prevalent agents of mastitis, considerations are made on the methods for the controlling of stafilococal infections in dairy cattle, in order to prevent the occurrence of toxins in milk and milk products.

Echocardiographic findings predict in-hospital and 1-year mortality in left-sided native valve Staphylococcus aureus endocarditis

DEFF Research Database (Denmark)

Lauridsen, Trine K.; Park, Lawrence; Tong, Steven Y C

2015-01-01

BACKGROUND: Staphylococcus aureus left-sided native valve infective endocarditis (LNVIE) has higher complication and mortality rates compared with endocarditis from other pathogens. Whether echocardiographic variables can predict prognosis in S aureus LNVIE is unknown. METHODS AND RESULTS......: Consecutive patients with LNVIE, enrolled between January 2000 and September 2006, in the International Collaboration on Endocarditis were identified. Subjects without S aureus IE were matched to those with S aureus IE by the propensity of having S aureus. Survival differences were determined using log...

Preliminary treatment of bovine mastitis caused by Staphylococcus aureus, with trx-SA1, recombinant endolysin of S. aureus bacteriophage IME-SA1.

Science.gov (United States)

Fan, Jindai; Zeng, Zhiliang; Mai, Kaijie; Yang, Yu; Feng, Jiaqi; Bai, Yang; Sun, Baoli; Xie, Qingmei; Tong, Yigang; Ma, Jingyun

2016-08-15

Methicillin-resistant Staphylococcus aureus (MRSA) has become a great threat to human and animal health and there is an urgent need to develop novel antibacterial agents to control this pathogen. The objective of this study was to obtain an active recombinant endolysin from the novel bacteriophage (IME-SA1), and conduct an efficacy trial of its effectiveness against bovine mastitis. We isolated a phage that was virulent and specific for S. aureus with an optimal multiplicity of infection of 0.01. Electron microscopy revealed that IME-SA1 was a member of the family Myoviridae, with an isometric head (98nm) and a long contractile tail (200nm). Experimental lysis experiments indicated the phage had an incubation period of 20min with a burst size of 80. When host bacteria were in early exponential growth stages, a multiplicity of infection of 0.01 resulted in a complete bacterial lysis after 9h. The endolysin gene (804bp) was cloned into the pET-32a bacterial expression vector and recombinant endolysin Trx-SA1 was successfully obtained with molecular size of about 47kDa. Preliminary results of therapeutic trials in cow udders showed that Trx-SA1 could effectively control mild clinical mastitis caused by S. aureus. The endolysin Trx-SA1 might be an alternative treatment strategy for infections caused by S. aureus, including MRSA. Copyright © 2016 Elsevier B.V. All rights reserved.

Staphylococcus aureus Meticilina Resistente (MRSA e Infecções Nosocomiais

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CRISTINA PAIVA SOUSA

2009-12-01

Full Text Available Um número crescente de cepas de Staphylococcus aureus meticilina resistente (MRSA apresentam resistência a múltiplos agentes antimicrobianos e são implicadas como causas de infecções hospitalares. S. aureus podem ser isolados de ambiente hospitalar e profissionais da saúde, revelando o risco de transmissão desses microrganismos pelo contato direto ou indireto com pacientes hospitalizados. Objetivou-se nesta revisão correlacionar este microrganismo com infecções hospitalares e avaliar as possíveis fontes de infecção, bem como enfatizar a importância do investimento em ações de educação em saúde que culminem em minimização de infecções hospitalares. Palavras-chave: Staphylococcus aureus meticilina resistente. Infecções nosocomiais.

Methicillin-Resistant Staphylococcus aureus Infections: A Comprehensive Review and a Plastic Surgeon's Approach to the Occult Sites.

Science.gov (United States)

Hunter, Cedric; Rosenfield, Lorne; Silverstein, Elena; Petrou-Zeniou, Panayiota

2016-08-01

Up to 20 percent of the general population is persistently colonized with Staphylococcus aureus, and 1 to 3 percent of the population is colonized with community-acquired methicillin-resistant S. aureus. Currently, the knowledge of methicillin-resistant Staphylococcus aureus carriage sites other than the nose, and their effect on surgical site infections in cosmetic surgery, is lacking. A comprehensive literature review using the PubMed database to analyze prevalence, anatomical carrier sites, current screening and decontamination protocols and guidelines, and methicillin-resistant S. aureus in cosmetic surgery was performed. The senior author's (L.R.) methicillin-resistant S. aureus infection experience and prevention protocols were also reviewed. Nasal swabs detect only 50.5 percent of methicillin-resistant S. aureus colonization, and broad screening has noted the presence of methicillin-resistant S. aureus in the ear canal and umbilicus. Decolonization protocols within the orthopedic and cardiothoracic surgery literature have reduced rates of methicillin-resistant S. aureus surgical-site infections. There are no decolonization guidelines for plastic surgeons. Since instituting their decolonization protocol, the authors have had no cases of methicillin-resistant S. aureus infection in nearly 1000 cosmetic surgery procedures. There are very limited, if any, Level I or II data regarding methicillin-resistant S. aureus screening and decolonization. As the sequelae of a surgical-site infection can be disastrous, expert opinions recommend that plastic surgeons vigorously address methicillin-resistant S. aureus colonization and infection. The authors have developed and recommend a simple decolonization protocol that includes treatment of the umbilicus, ear canal, and nares to limit surgical-site infection and improve surgical outcomes.

Prevalence of Methicillin and Vancomycin resistant Staphylococcus aureus colonization in nasopharynx; Amir-Alam hospital, 2005

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Hasibi M

2007-07-01

Full Text Available Background: Staphylococcus aureus is one of the most common causes of nosocomial infections with high morbidity and mortality rate. Traditionally, methicillin resistant staphylococcus aureus has been considered a major nosocomial pathogen in healthcare facilities, but in the past decade, it has been observed emerging in the community as well. Informations regarding hospital microbial colonization could be an important step for prevention of nosocomial infections. Our objective was clarifying the prevalence of methicillin resistant and vancomycin resistant staphylococcus aureus colonization in nasopharynx. Methods: A descriptive cross sectional study was carried on 106 patients and nursing staff of surgery and hemodialysis wards in Amir-Alam hospital from April 2005 to July 2005. The samples were collected from nasal region of cases using cotton swab by two experienced technician and were sent to laboratory for culture and antibiogram. Results: Twenty six (29.5% out of 106 cases were nasopharyngeal carriers of staphylococcus aureus. Eight cases (7.5% had methicillin resistant staphylococcus aureus. The most frequent colonization rate was seen in hemodialysis nursing staff and in all of them methicillin resistant staphylococcus aureus was reported. Carrier rates in hemodialysis patients were twice compared to surgery ward patients. The interesting point was that no sample of vancomycin resistant staphylococcus aureus was isolated. Conclusion: Prevalence of methicillin resistant staphylococcus aureus colonization seems to be increased; therefore proper management for controlling this problem is mandatory. The results of the present study suggest that the prevalence of methicillin resistant staphylococcus aureus infections is higher than was expected in Iran and vigorous preventive strategies should therefore be taken to stop the growth of this major health problem.

MicroRNA-24 Modulates Staphylococcus aureus-Induced Macrophage Polarization by Suppressing CHI3L1.

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Jingjing, Zhang; Nan, Zhang; Wei, Wu; Qinghe, Guo; Weijuan, Wang; Peng, Wang; Xiangpeng, Wang

2017-06-01

Macrophages play a crucial role in host innate anti-Staphylococcus aureus defense, which is tightly regulated by multiple factors, including microRNAs. A recent study showed that miR-24 plays an important role in macrophage polarization. Here, we investigated the biological function of miR-24 in S. aureus-stimulated macrophages. The results revealed that miR-24 expression was significantly decreased in both human and mouse macrophage cell lines with S. aureus stimulation in a time-dependent manner. Moreover, miR-24 overexpression significantly decreased the production of M1 phenotype markers, such as IL-6, iNOS, TNF-α, CD86, and CD80, whereas it increased the production of M2 markers, such as Arg1, CCL17, CCL22, CD163, and CD206, in S. aureus-stimulated macrophages. Conversely, knockdown of miR-24 promoted M1 macrophage polarization but diminished M2 macrophage polarization in S. aureus-stimulated macrophages. Furthermore, CHI3L1 was predicted as a target gene of miR-24 using bioinformatics software and identified by luciferase reporter assay. Additionally, miR-24 overexpression inhibited CHI3L1 expression and downregulated the downstream MAPK pathway in S. aureus-stimulated macrophages. Finally, CHI3L1 overexpression rescued macrophage polarization and MAPK pathway inhibition induced by miR-24 mimic transfection in S. aureus-stimulated macrophages. In conclusion, the data suggest that miR-24 serves as a molecular regulator in S. aureus-induced macrophage polarization through targeting of CHI3L1 and regulation of the MAPK pathway, which may provide a promising therapeutic target for S. aureus-related infections and inflammatory diseases.

Prevalence of Staphylococcus aureus colonization in renal transplant patients

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Luiz Carlos Ribeiro Lamblet

2014-10-01

Full Text Available Objective to evaluate the prevalence of Staphylococcus aureus nasal colonization in renal transplant patients and to identify the related risk factors. Method Swabs were used to collect nasal samples from 160 patients who had undergone a transplant within the previous year at the Kidney and Hypertension Hospital. The ‘National Committee for Clinical Laboratory Standards’ norms were followed for the collection, isolation, identification and sensitivity measurements. Results There was a 9.4% (15 prevalence of Staphylococcus aureus nasal colonization, of which one (6.7% was resistant to oxacillin. It was possible to identify as an associated risk factor a wait of more than one year for accessing dialysis prior to the transplant (p=0.029. Conclusion Given the high morbidity and mortality rates that this microorganism causes in the target population, other studies should be carried out, and pre- and post-transplant screening should occur in order to develop strategies that improve the prevention and control of the spread of Staphylococcus aureus.

Biofilm Formation of Staphylococcus aureus on Various Surfaces and Their Resistance to Chlorine Sanitizer.

Science.gov (United States)

Lee, Jung-Su; Bae, Young-Min; Lee, Sook-Young; Lee, Sun-Young

2015-10-01

This study investigated the effect of material types (polystyrene, polypropylene, glass, and stainless steel) and glucose addition on Staphylococcus aureus biofilm formation, and the relationship between biofilm formation measured by crystal violet (CV) staining and the number of biofilm cells determined by cell counts was studied. We also evaluated the efficacy of chlorine sanitizer on inhibiting various different types of S. aureus biofilms on the surface of stainless steel. Levels of biofilm formation of S. aureus were higher on hydrophilic surfaces (glass and stainless steel) than on hydrophobic surfaces (polypropylene and polystyrene). With the exception of biofilm formed on glass, the addition of glucose in broth significantly increased the biofilm formation of S. aureus on all surfaces and for all tested strains (P ≤ 0.05). The number of biofilm cells was not correlated with the biomass of the biofilms determined using the CV staining method. The efficacy of chlorine sanitizer against biofilm of S. aureus was not significantly different depending on types of biofilm (P > 0.05). Therefore, further studies are needed in order to determine an accurate method quantifying levels of bacterial biofilm and to evaluate the resistance of bacterial biofilm on the material surface. Biofilm formation of Staphylococcus aureus on the surface was different depending on the surface characteristics and S. aureus strains. There was low correlation between crystal violet staining method and viable counts technique for measuring levels of biofilm formation of S. aureus on the surfaces. These results could provide helpful information for finding and understanding the quantification method and resistance of bacterial biofilm on the surface. © 2015 Institute of Food Technologists®

Characterization of Staphylococcus aureus Strains Associated with Food Poisoning in Shenzhen, China

NARCIS (Netherlands)

Yan, Xiaomei; Wang, Bing; Tao, Xiaoxia; Hu, Qinghua; Cui, Zhigang; Zhang, Jianzhong; Lin, Yiman; You, Yuanhai; Shi, Xiaolu; Grundmann, Hajo

To characterize isolates of Staphylococcus aureus that were associated with staphylococcal food poisoning between 2006 and 2009 in Shenzhen, Southern China, a total of 52 Staphylococcus aureus isolates from 11 outbreaks were analyzed by using multilocus sequence typing (MLST), spa typing, and

Staphylococcus aureus innate immune evasion is lineage-specific: a bioinfomatics study.

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McCarthy, Alex J; Lindsay, Jodi A

2013-10-01

Staphylococcus aureus is a major human pathogen, and is targeted by the host innate immune system. In response, S. aureus genomes encode dozens of secreted proteins that inhibit complement, chemotaxis and neutrophil activation resulting in successful evasion of innate immune responses. These proteins include immune evasion cluster proteins (IEC; Chp, Sak, Scn), staphylococcal superantigen-like proteins (SSLs), phenol soluble modulins (PSMs) and several leukocidins. Biochemical studies have indicated that genetic variants of these proteins can have unique functions. To ascertain the scale of genetic variation in secreted immune evasion proteins, whole genome sequences of 88 S. aureus isolates, representing 25 clonal complex (CC) lineages, in the public domain were analysed across 43 genes encoding 38 secreted innate immune evasion protein complexes. Twenty-three genes were variable, with between 2 and 15 variants, and the variants had lineage-specific distributions. They include genes encoding Eap, Ecb, Efb, Flipr/Flipr-like, Hla, Hld, Hlg, Sbi, Scin-B/C and 13 SSLs. Most of these protein complexes inhibit complement, chemotaxis and neutrophil activation suggesting that isolates from each S. aureus lineage respond to the innate immune system differently. In contrast, protein complexes that lyse neutrophils (LukSF-PVL, LukMF, LukED and PSMs) were highly conserved, but can be carried on mobile genetic elements (MGEs). MGEs also encode proteins with narrow host-specificities arguing that their acquisition has important roles in host/environmental adaptation. In conclusion, this data suggests that each lineage of S. aureus evades host immune responses differently, and that isolates can adapt to new host environments by acquiring MGEs and the immune evasion protein complexes that they encode. Cocktail therapeutics that targets multiple variant proteins may be the most appropriate strategy for controlling S. aureus infections. Copyright © 2013 Elsevier B.V. All rights

Rapid Differentiation between Livestock-Associated and Livestock-Independent Staphylococcus aureus CC398 Clades

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Larsen, Jesper; Soldanova, Katerina; Aziz, Maliha; Contente-Cuomo, Tania; Petersen, Andreas; Vandendriessche, Stien; Jiménez, Judy N.; Mammina, Caterina; van Belkum, Alex; Salmenlinna, Saara; Laurent, Frederic; Skov, Robert L.; Larsen, Anders R.; Andersen, Paal S.; Price, Lance B.

2013-01-01

Staphylococcus aureus clonal complex 398 (CC398) isolates cluster into two distinct phylogenetic clades based on single-nucleotide polymorphisms (SNPs) revealing a basal human clade and a more derived livestock clade. The scn and tet(M) genes are strongly associated with the human and the livestock clade, respectively, due to loss and acquisition of mobile genetic elements. We present canonical single-nucleotide polymorphism (canSNP) assays that differentiate the two major host-associated S. aureus CC398 clades and a duplex PCR assay for detection of scn and tet(M). The canSNP assays correctly placed 88 S. aureus CC398 isolates from a reference collection into the human and livestock clades and the duplex PCR assay correctly identified scn and tet(M). The assays were successfully applied to a geographically diverse collection of 272 human S. aureus CC398 isolates. The simple assays described here generate signals comparable to a whole-genome phylogeny for major clade assignment and are easily integrated into S. aureus CC398 surveillance programs and epidemiological studies. PMID:24244535

Photodynamic Action of LED-Activated Curcumin against Staphylococcus aureus Involving Intracellular ROS Increase and Membrane Damage

Directory of Open Access Journals (Sweden)

Yuan Jiang

2014-01-01

Full Text Available Aim. To investigate the effect of photodynamic action of LED-activated curcumin on cell viability, membrane permeability, and intracellular reactive oxygen species of Staphylococcus aureus. Methods. Staphylococcus aureus was incubated with the different concentrations of curcumin for 60 min and then irradiated by blue light with the wavelength of 470 nm and with light dose of 3 J/cm2. The colony forming unit assay was used to investigate photocytotoxicity of curcumin on Staphylococcus aureus, confocal laser scanning microscopy (CLSM and flow cytometry (FCM for assaying membrane permeability, FCM analysis with DCFH-DA staining for measuring the intracellular ROS level, and transmission electron microscopy (TEM for observing morphology and structure. Results. Blue light-activated curcumin significantly killed Staphylococcus aureus in a curcumin dose-dependent manner. TEM observed remarkable structural damages in S. aureus after light-activated curcumin. More red fluorescence of PI dye was found in S. aureus treated by blue light-activated curcumin than in those of the controlled bacterial cells. Intracellular ROS increase was observed after light-activated curcumin. Conclusion. Blue light-activated curcumin markedly damaged membrane permeability, resulting in cell death of Staphylococcus aureus and highlighted that intracellular ROS increase might be an important event in photodynamic killing of Staphylococcus aureus in the presence of curcumin.

spa typing and antimicrobial resistance of Staphylococcus aureus from healthy humans, pigs and dogs in Tanzania

DEFF Research Database (Denmark)

Katakweba, Abdul S.; Muhairwa, Amandus P.; Espinosa-Gongora, Carmen

2016-01-01

. aureus carrier frequencies in dogs and humans were within the expected range and low in pigs. The S. aureus spa types circulating in the community were generally not shared by different hosts and majority of types belonged to known clones. Besides ampicillin resistance, moderate levels of antimicrobial......Introduction: Staphylococcus aureus is an opportunistic pathogen causing infections in humans and animals. Here we report for the first time the prevalence of nasal carriage, spa typing and antimicrobial resistance of S. aureus in a Tanzanian livestock community. Methodology: Nasal swabs were taken...... from 100 humans, 100 pigs and 100 dogs in Morogoro Municipal. Each swab was enriched in Mueller Hinton broth with 6.5% NaCl and subcultured on chromogenic agar for S. aureus detection. Presumptive S. aureus colonies were confirmed to the species level by nuc PCR and analysed by spa typing...

Prevalence and resistance of commensal Staphylococcus aureus, including meticillin-resistant Staphylococcus aureus: a European cross-sectional study.

NARCIS (Netherlands)

Heijer, C.D.J. den; Bijnen, E.M.E. van; Paget, W.J.; Pringle, M.; Goossen, H.; Bruggeman, C.A.; Schellevis, F.G.; Stobberingh, E.E.

2014-01-01

Background: Information on the prevalence of Staphylococcus aureus resistance has mainly been obtained from invasive strains, although the commensal flora is considered an important reservoir of resistance. Within ‘The Appropriateness of prescribing antibiotics in primary health care in Europe with

Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk.

Science.gov (United States)

Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

2015-06-01

The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene.

Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk

Science.gov (United States)

Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A.; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

2015-01-01

The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene. PMID:26273271

Testing the sensitivity of Staphylococcus aureus antibiotics

Directory of Open Access Journals (Sweden)

Marioara Nicoleta FILIMON

2009-11-01

Full Text Available This study has in view to establish and test the sensitivity of Staphylococcus aureus antibiotics. There are different injuries caused by superficial skin infections: from simple pimples to infections that endanger our lives, like an abscess, furuncle septicemia, meningitis, toxic food, urinary tract infection at sexually active young women. Samples have been taken from 30 people with staphylococcus infections. They were nineteen women and eleven men, between the age of 2 and 79. During this study some antibiograms have been made, based on pharyngeal exudates, acne secretion and urine culture. It has been established that the most efficient recommended antibiotics are: oxacilin, erythromycin, rifampicin and ciprofloxacin. The penicillin turned out to be less efficient to remove and destroy the Staphylococcus aureus species.

Epidemiology and antibiotic sensitivity of Staphylococcus aureus nasal carriage in children in Hungary.

Science.gov (United States)

Laub, Krisztina; Tóthpál, Adrienn; Kardos, Szilvia; Dobay, Orsolya

2017-03-01

The aim of this study was to assess the Staphylococcus aureus nasal carriage rate in healthy children all over Hungary and to specify some risk factors, the antibiotic resistance patterns of the bacteria, and their genetic relatedness. In total, 878 children (aged 3-6 years) were screened at 21 day-care centers in 16 different cities in Hungary, between February 2009 and December 2011. Samples taken from both nostrils were cultured on blood agar, and suspected S. aureus isolates were identified by β-hemolysis, catalase positivity, clump test, and nucA PCR. Methicillin-resistant strains were screened by mecA and mecC PCR. Antibiotic susceptibility was determined by agar dilution or gradient test strips. Pulsed-field gel electrophoresis was used for genotyping. S. aureus carriage rate was found to be 21.3%, which correlates well with international data. We found no statistically significant correlation between the gender or the sibling status and S. aureus carriage. All isolates were sensitive to oxacillin, trimethoprim-sulfamethoxazole, and mupirocin. The resistance rates for erythromycin, ciprofloxacin, clindamycin, gentamicin, and tetracycline were 7.5%, 0.5%, 1.1%, 3.7%, and 4.3%, respectively. The isolates showed very high genetic diversity. In summary, carried S. aureus isolates are more sensitive to antibiotics compared with clinical isolates in Hungary, and methicillin-resistant S. aureus carriage rate is very low yet.

Tracing and inhibiting growth of Staphylococcus aureus in barbecue cheese production after product recall.

Science.gov (United States)

Johler, S; Zurfluh, K; Stephan, R

2016-05-01

Staphylococcal food poisoning is one of the most prevalent causes of foodborne intoxication worldwide. It is caused by ingestion of enterotoxins formed by Staphylococcus aureus during growth in the food matrix. Following a recall of barbecue cheese due to the detection of staphylococcal enterotoxins in Switzerland in July 2015, we analyzed the production process of the respective dairy. Although most cheese-making processes involve acidification to inhibit the growth of pathogenic bacteria, barbecue cheese has to maintain a pH >6.0 to prevent undesired melting of the cheese. In addition, the dairy decided to retain the traditional manual production process of the barbecue cheese. In this study, therefore, we aimed to (1) trace Staph. aureus along the barbecue cheese production process, and (2) develop a sustainable strategy to inhibit growth of Staph. aureus and decrease the risk of staphylococcal food poisoning without changing the traditional production process. To this end, we traced Staph. aureus in a step-wise blinded process analysis on 4 different production days using spa (Staphylococcus protein A gene) typing, DNA microarray profiling, and pulsed-field gel electrophoresis analysis. We subsequently selected a new starter culture and used a model cheese production including a challenge test assay to assess its antagonistic effect on Staph. aureus growth, as well as its sensory and technological implications. We detected Staph. aureus in 30% (37/124) of the collected samples taken from the barbecue cheese production at the dairy. This included detection of Staph. aureus in the final product on all 4 production days, either after enrichment or using quantitative detection. We traced 2 enterotoxigenic Staph. aureus strains (t073/CC45 and t282/CC45) colonizing the nasal cavity and the forearms of the cheesemakers to the final product. In the challenge test assay, we were able to show that the new starter culture inhibited growth of Staph. aureus while meeting