Phenotypic and genotypic characterization of oxacillin-susceptible and mecA positive Staphylococcus aureus strains isolated in Uruguay.

The aim of this study was to characterize phenotypically and genotypically 27 mecA positive Staphylococcus aureus strains with oxacillin MICs of ≤2µg/ml by Vitek 2, isolated in different regions of Uruguay. Susceptibility to oxacillin and cefoxitin was studied by gradient diffusion, disk diffusion to cefoxitin, and Phoenix and MicroScan systems. PBP2a was determined. SCCmec typing was performed and the isolates were compared by PFGE. Twenty-six isolates were susceptible to oxacillin; one strain was susceptible to cefoxitin by disk diffusion and 3 strains by gradient diffusion. Phoenix and MicroScan panels detected methicillin resistance in 25 and 27 strains, respectively. Twenty-six strains tested positive for PBP2a. Twenty-six strains carried SCCmec V and 24 belonged to pulsotype A. One strain carried SCCmec IV and did not belong to pulsotype A. Cefoxitin disk diffusion test and PBP2a detection correctly identified 26 of these 27 strains as MRSA. PFGE results suggest the dissemination of a cluster of MRSA carrying SCCmec V.

Tercer caso de vasculitis leucocitoclástica cutánea secundaria al uso de oxacilina: reporte de caso / Third case in the literature of cutaneous leukocytoclastic vasculitis secondary to oxacilin use

Resumen La vasculitis leucocitoclastica es una patologìa que compromete los vasos pequeños y cuya causa predominantemente se ha descrito como idiopatica. Se presenta el caso de una mujer de 78 años hipertensa, diabética y con enfermedad renal crónica en estadio 5, que presentó lesiones limitadas a la piel posterior a la administración de oxacilina para manejo de bacteremia por SAMS. La presentación clínica se basó en purpuras palpables predominantemente en miembros inferiores y lesiones dolorosas coalescentes que formaban ampollas de contenido hemorrágico. Estas lesiones resolvieron gradualmente después del cambio de la terapia mencionada anteriormente. La biopsia fue compatible con vasculitis leucocitoclástica, con paraclínicos que descartaron causas infecciosas y autoinmunes.

Abstract Leukocytoclastic vasculitis is a pathology that involves small vessels and whose cause has been predominantly described as idiopathic. The clinical case of a 78-year-old woman with hypertension, diabetic and chronic stage 5 kidney disease, who presented limited skin lesions after administration of oxacillin for management of bacteremia by MSSA. The clinical presentation consisted on palpable purpura predominantly in the lower limbs and painful coalescent lesions that formed blisters of hemorrhagic content. Lesions gradually resolved after the change of the therapy mentioned above. The biopsy was compatible with leukocytocastic vasculitis, with paraclinics who ruled out infectious and autoimmune causes.

Talinum paniculatum leaves with in vitro antimicrobial activity against reference and clinical strains of Staphylococcus aureus interfere with oxacillin action / Las hojas de Talinum paniculatum con actividad antimicrobiana in vitro contra cepas de referencia y clínicas de Staphylococcus aureus interfieren con la acción de la oxacilina

SUMMARY Propose: We evaluated the antibacterial potential of the crude leaf extract (CLE) and fractions hexane (HX) and ethyl acetate (EtOAc) from Talinum paniculatum alone and in association with oxacillin (OXA) against OXA-resistant Staphylococcus aureus (ORSA, environment isolates) and OXA-sensitive S. aureus (OSSA, ATCC 25923). Furthermore, toxicity tests were performed. Methods: The antibacterial activity was evaluated through checkerboard assay (broth microdilution) to establish the minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC). Toxicity test in mice was assessed. Results: The MIC values for the CLE and its fractions against ORSA and OSSA were in the order of HX (500 μg ml-1) = EtOAc < CLE (4000 μg ml-1). EtOAc and HX presented outstanding antibacterial activities against ORSA, and these fractions were bactericidal toward OSSA. Conversely, the associations between plant product (CLE, EtOAc, or HX) and OXA exhibited no synergistic effects. During these associations, there was an increase in OXA MICs anywhere from 2- to 4092-fold. The CLE presented absence of toxicity at a dose of 5 g kg-1 (in vivo). Conclusion: Although T. paniculatum be a good source of bioactive compounds with antistaphylococcal potential, the researchers should be cautious, since its edible leaf may interfere with OXA therapy (mitigating OXA-induced growth inhibition or killing of S. aureus and enhancing S. aureus resistance).

RESUMEN Propósito: evaluamos el potencial antibacteriano del extracto de hoja en bruto (EHB) y las fracciones hexano (HX) y acetato de etilo (AcOEt) de Talinum paniculatum solo y en asociación con oxacilina (OXA) contra Staphylococcus aureus resistente a OXA (ORSA, ambientales) y S. aureus sensible a OXA (OSSA, ATCC 25923). Además, se realizaron pruebas de toxicidad. Métodos: la actividad antibacteriana se evaluó mediante microdilución en caldo para establecer las concentraciones inhibitorias mínimas (CIM) y bactericidas mínimas (CBM). Se evaluó la toxicidad en ratones. Resultados: los valores de CIM para el EHB y sus fracciones contra ORSA y OSSA fueron del orden de HX (500 μg ml-1) = AcOEt < EHB (4000 μg ml-1). AcOEt y HX presentaron actividades antibacterianas sobresalientes contra ORSA, y estas fracciones fueron bactericidas hacia OSSA. Por el contrario, las asociaciones entre el producto vegetal (EHB, AcOEt o HX) y OXA no mostraron efectos sinérgicos. Durante estas asociaciones, hubo un aumento en las CIM de OXA de 2 a 4092 veces. EHB no mostró toxicidad a una dosis de 5 g kg-1. Conclusión: aunque T. paniculatum es una buena fuente de compuestos bioactivos con potencial antiestofilocócico, los investigadores deben ser cautelosos, ya que su hoja comestible puede interferir con la terapia con OXA (mitigando la inhibición del crecimiento inducida por OXA o la muerte de S. aureus y promoviendo resistencia bacteriana).

Chemical composition and antimicrobial activity of two extract of propolis against isolates of Staphylococcus spp. and multiresistant bacterials / Composição química e atividade antimicrobiana de dois extratos de própolis contra isolados de Staphylococcus spp. e bactérias multirresistentes

There is a growing need to discover and develop alternative therapies for the treatment of mastitis caused by Staphylococcus spp. and multidrug-resistant bacterial infections. This study examined the chemical composition and antimicrobial potential of two propolis extracts (EPA and EPB) against seventy-seven isolates of Staphylococcus spp. obtained from subclinical bovine mastitis; three clinical strains of MRSA and two from clinical strains of S. aureus ATCC, identified as S. aureus ATCC 6538 and S. aureus ATCC 25923. The total phenolic content was determined by the Folin-Ciocalteau method, the total flavonoid content by the Dowd method and the phenolic profile was quantified by HPLC-DAD. The MBC values of the extracts were evaluated by broth microdilution method. The amount of total phenolic and flavonoid compounds was higher in EPA than EPB. Both extracts revealed the presence of caffeic, coumaric, cinnamic, ferulic and 3,4-dihydroxybenzoic acids, with higher concentrations of coumaric and cinnamic acids. Staphylococcus spp. isolates were susceptible to EPA (90.9%), EPB (83.1%) and oxacillin (80.5%). The oxacillin susceptible isolates were also susceptible to EPA (70.1%) and EPB (80.6%), whereas those oxacillin-resistant strains were also susceptible to EPA (40.0%) and to EPB (26.7%). MBC ranged from 34.3 to 68.7µm/mL for EPA and from 68.7 to 137.5µg/mL for EPB. Both extracts inhibited significantly (100%) the clinical strains of MRSA, S. aureus ATCC 6538 and S. aureus ATCC 25923 at the concentration of 68.7µg/mL. It is concluded that both extracts of propolis, whose main constituents are coumaric and cinnamic acids, have high antimicrobial activity against the microorganisms studied, and EPA also against oxacillin-resistant strains. These findings reinforce its potential use for the treatment of bovine mastitis.(AU)

É cada vez mais oportuna a necessidade de descobrir e desenvolver terapias alternativas para tratamento da mastite causada por Staphylococcus spp. e de infecções bacterianas multirresistentes. Este estudo examinou a composição química e o potencial antimicrobiano de dois extratos etanólicos de própolis (EPA e EPB) contra setenta e sete isolados de Staphylococcus spp. obtidos a partir de mastite bovina subclínica; três estirpes clínicas de MRSA e duas de linhagens clínicas de S. aureus ATCC, identificadas como, S. aureus ATCC 6538 e S. aureus ATCC 25923, ambas metacilina resistentes. O teor total de fenólicos foi determinado pelo método de Folin-Ciocalteau, o teor de flavonoides totais pelo método Dowd e o perfil fenólico foi quantificado por HPLC-DAD. CBM dos extratos foi avaliada pelo método de microdiluição em caldo. A quantidade total de compostos fenólicos e flavonoides foi maior no EPA do que no EPB. Ambos os extratos revelaram a presença dos ácidos cafeico, cumárico, cinâmico, ferúlico e 3,4-di-hidroxibenzóico, com maiores concentrações de ácidos cumárico e cinâmico. Os isolados de Staphylococcus spp. foram sensíveis a EPA (90,9%), EPB (83,1%) e oxacilina (80,5%). Os isolados suscetíveis à oxacilina também foram suscetíveis ao EPA (70,1%) e ao EPB (80,6%), enquanto os do resistente à oxacilina foram suscetíveis ao EPA (40,0%) e ao EPB (26,7%). MBC variou de 34,3 a 68,7µm/mL para EPA e de 68,7 a 137,5µg/mL para EPB. Ambos os extratos inibiram significativamente (100%) as linhagens clínicas de MRSA, S. aureus ATCC 6538 e S. aureus ATCC 25923 na concentração de 68,7µg/mL. Conclui-se que os extratos etanólicos da própolis, cujos principais constituintes são os ácidos cumário e cinâmico, possuem atividade antimicrobiana contra os micro-organismos estudados, e o EPA também contra as cepas resistentes à oxacilina. Estes achados reforçam seu potencial uso para o tratamento da mastite bovina.(AU)

Perfil de resistência da Escherichia coli, isoladas de água e ostras, aos betalactâmicos / Profile resistance of Escherichia coli, isolated from water and oysters, to betalactams

Com o objetivo de avaliar o grau de contaminação por coliformes presentes na água e em ostras e isolar cepas de Escherichia coli para testar seu perfil de resistência aos antibióticos β-lactâmicos, foram coletadas amostras de água e ostras nas regiões de Baixão de Guaí e Capanema, Estuário da Baía do Iguape, BA. A partir das análises microbiológicas de contagem de coliformes à 35ºC e 45ºC, cepas de E. coli foram isoladas e identificadas para realização dos testes de suscetibilidade aos antimicrobianos pertencentes a família dos β-lactâmicos – amoxicilina (10μg), ampicilina (10μg), azetronan (30μg), imipenem (10μg), cefalotina (30μg), ceftriaxona (30μg), oxacilina (1μg), utilizando a técnica de difusão de disco em placas. Foi verificado que todos os isolados apresentaram resistência à oxacilina, em contrapartida 100% das cepas de E. coli avaliadas demonstraram perfil de sensibilidade à azetronam, seguidas por 97% ao imepenem e ceftriaxona e 90% à ampicilina.

Ceftaroline resistance in Staphylococcus pseudintermedius gene mecA carriers / Resistência à ceftarolina em Staphylococcus pseudintermedius portadores do gene mecA

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) being a constant concern, ceftaroline fosamil has been recently approved as a new cephalosporin, active against MRSA, for use in humans; only rare cases of resistance have been reported till date. There is no report of resistance to ceftaroline in Staphylococcus pseudintermedius, which is the main bacterium causing dermatitis and otitis in dogs. To evaluate staphylococcal resistance to ceftaroline, 35 isolates of methicillin-resistant S. pseudintermedius (MRSP), carrying the mecA gene, from 26 dogs with folliculitis and nine dogs with external otitis, underwent disk diffusion test with cefoxitin, oxacillin, and ceftaroline. Tests with cefoxitin and oxacillin showed > 90% sensitivity in methicillin resistance detection. In the disk diffusion test, 97.14% (34/35) were resistant to cefoxitin, 94.29% (33/35) to oxacillin, and 31.43% (11/35) to ceftaroline. Of the ceftaroline-resistant strains, 27.27% (3/11) were obtained from the ears of dogs while the rest (8/11) were from the skin. The current report is the first description of MRSP resistance to ceftaroline.(AU)

Infecções causadas por Staphylococcus aureus resistente à meticilina (MRSA) são uma preocupação médica constante. A ceftarolina fosamila é uma nova cefalosporina ativa contra Staphylococcus aureus resistente à meticilina recentemente aprovada para uso em humanos e raros casos de resistência relatados até agora. Não há relatos de resistência à ceftarolina em Staphylococcus pseudintermedius, principal bactéria causadora de dermatite e otite em cães. Com o objetivo de avaliar a resistência estafilocócica à ceftarolina, 35 amostras de S. pseudintermedius resistentes à meticilina (MRSP), portadoras do gene mecA, provenientes de 26 cães com foliculite e 9 com otite externa foram submetidos ao teste de disco-difusão com cefoxitina, oxacilina e ceftarolina. Os testes realizados com cefoxitina e oxacilina mostraram mais de 90% de sensibilidade na detecção da resistência à meticilina em ambas. No teste da disco-difusão, 97,14% (1/35) foram resistentes à cefoxitina, 94,29% (3/35) à oxacilina e 31,43% (11/35) à ceftarolina. Das cepas resistentes às ceftarolina, 27,27 (3/11) foram provenientes de ouvido de cães e as demais (8/11), provenientes da pele, sendo essa primeira descrição de resistência de MRSP à ceftarolina na literatura atual.(AU)

Prevalence and in vitro susceptibility of methicillin-resistant Staphylococcus pseudintermedius (MRSP) from skin and nostrils of dogs with superficial pyoderma / Prevalência e suscetibilidade in vitro de Staphylococcus pseudintermedius resistente à meticilina (MRSP) oriundos de pele e narinas de cães com piodermite superficial

In order to assess the prevalence of Methicillin-resistant Staphylococcus pseudintermedius from skin and nostrils of dogs with pyoderma, to determine its in vitro susceptibility, and to correlate these data with the presence of the mecA gene, 43 dogs were selected. Samples were collected from secretion of their skin lesions and right nostril, cultured, and analyzed for phenotypic and genotypic characteristics of the bacteria studied. In 62 samples (91%) the microorganism was classified as S. pseudintermedius. The rate of resistance against antibiotics ranged from 7% (amikacin; 4/62) to 77% (sulfamethoxazole + trimethoprim; 48/62). Resistance against oxacillin was found in 34% of the samples (21/62). Twenty-five samples (37%) were strains that carried the mecA gene. A significant correlation (P<0.01) was found between presence of the mecA gene and oxacillin resistance. Seventeen dogs were mecA gene carriers, and 8 (47%) of them had the gene in the skin lesions and nostril. A significant correlation (P<0.01) was also observed between the presence of mecA gene in the skin lesions and nostrils. Oxacillin resistance in vitro can be safely used to indicate the presence of mecA gene in MRSP samples. The nostrils can be a reservoir of MRSP in dogs.(AU)

Para acessar a prevalência de MRSP na pele e nas narinas de cães com piodermite superficial, determinar a suscetibilidade in vitro, e correlacionar estes dados com a presença do gene mecA, foram selecionados 43 cães. Amostras de lesões de pele e narinas foram coletadas, cultivadas, e analisadas fenotipica e genotipicamente. Em 62 amostras (91%), os microrganismos foram classificados como Staphylococcus pseudintermedius. A taxa de resistência a antibióticos variou entre 7% (amicacina; 4/62) e 77% (sulfamethoxazol + trimetoprim; 48/62). Resistência a oxacilina foi observada em 34% das amostras (21/62). Vinte e cinco amostras (37%), eram cepas portadoras do gene mecA. Correlação significativa (P<0,01) foi observada entre a presença do gene mecA e a resistência à oxacilina. Considerando os cães, 17 eram portadores de cepas com gene mecA e 8(47%) delas carreavam este gene nas amostras de lesão de pele e nas narinas. Correlação significativa (P>0,01) foi observada entre a presença do gene mecA nas lesões de pele e nas narinas. Sendo assim, resistência à oxacilina in vitro pode ser aferida com segurança para indicar a presença do gene mecA em amostras de MRSP, e as narinas podem constituir em um reservatório dos microorganismos em cães.(AU)

Resistencia a oxacilina, eritromicina y gentamicina en cepas de Staphylococcus coagulasa negativa aisladas de hemocultivos / Resistance to oxacillin, erythromycin and gentamycin in coagulase negative Staphylococcus strains isolated from blood cultures

La resistencia a los antimicrobianos en bacterias Gram positivas como Staphylococcus coagulasa negativa constituye una amenaza mundial emergente. El propósito de la presente investigación fue identificar los genes de resistencia a oxacilina (mecA), eritromicina (erm y msrA), y gentamicina aac(6´)/aph(2´´), en cepas de Staphylococcus coagulasa negativa aisladas de hemocultivos de pacientes atendidos en el Hospital Universitario de Maracaibo. La detección fenotípica se realizó mediante métodos automatizados. Se utilizó la reacción en cadena de la polimerasa para detectar la presencia de genes de resistencia a los antimicrobianos. Se estudiaron 34 cepas cuya distribución por especie fue: S. haemolyticus (38,23%), S. epidermidis (29,42%), S. hominis (26,47%), S. xylosus y S. capitis (5,88% cada uno). Todas las cepas fueron resistentes a oxacilina. La resistencia a gentamicina varió entre 38,46% y 100%; mientras que la resistencia a eritromicina osciló entre 77,78% y 100%. Los análisis mostraron la presencia de los genes mecA (100%), ermA (35,2%), ermC (41,17%), msrA (17,64%), y aac(6´)/aph(2´´) (61,76%). En conclusión, se encontró una alta frecuencia de genes de resistencia a estos antibióticos y la Unidad de Cuidados Intensivos fue el servicio médico donde se aisló el mayor porcentaje de cepas portadoras de estos genes.

Resistance to antimicrobials in Gram-positive bacteria such as coagulase negative Staphylococcus is an emerging global threat. The purpose of this research was to identify the genes for resistance to oxacillin (mecA), erythromycin (erm and msrA), and gentamicin aac(6´)/aph(2´´), in Staphylococcus coagulase negative strains isolated from blood cultures from patients attended at the University Hospital in Maracaibo. Phenotypic detection was performed using automated methods. Polymerase chain reaction was used for the detection of antimicrobial resistance genes. Be studied 34 strains whose distribution by species was: S. haemolyticus (38.23%), S. epidermidis (29.42%), S. hominis (26.47%), S. xylosus and S. capitis (5.88% each one). All strains were resistant to oxacillin. Gentamicin resistance varied between 38.46% and 100%; while the erythromycin resistance ranged between 77.78% and 100%. The analyses showed the presence of genes mecA (100%), ermA (35.2%), ermC (41.17%), msrA (17.64%), and aac(6´)/aph (2´´) (61,76%). In conclusion, is found a high frequency of genes for resistance to these antibiotics and the intensive care unit was the health service where the highest percentage of isolated strains carriers of these genes.

Empirical antimicrobial therapy for late-onset sepsis in a neonatal unit with high prevalence of coagulase-negative Staphylococcus / Terapia antimicrobiana empírica para sepse tardia na unidade neonatal com alta prevalência de Staphylococcus coagulase negativo

Abstract Objective: The aim of this study was to compare two different empiric treatments for late-onset neonatal sepsis, vancomycin and oxacillin, in a neonatal intensive care unit with a high prevalence of coagulase-negative Staphylococcus. Methods: A cross-sectional study was conducted in an neonatal intensive care unit from 2011 to 2014. Data from the medical records of at-risk newborns were collected daily. Infections were defined according to the National Health Surveillance Agency criteria. Data analysis was performed using an internal program. Results: There was a significant reduction in the number of Staphylococcus aureus infections (p = 0.008), without endocarditis, meningitis, or lower respiratory tract infection, as well as a reduction in the frequency of deaths related to S. aureus infection. There were no significant changes in the incidence of Gram-negative bacterial or fungal infections. An increase in coagulase-negative Staphylococcus infections was observed (p = 0.022). However, there was no measured increase in related morbidity and mortality. There was a reduction in the median number of days of treatment with oxacillin from 11.5 to 6 days (p < 0.001) and an increase of one day in the median number of days of treatment with vancomycin (p = 0.046). Conclusions: Modification of the empiric treatment regimen for neonatal late-onset sepsis with use of oxacillin showed a significant reduction in S. aureus infections, as well as a reduction in the frequency of infections with major organ system involvement and mortality due to infection with this microorganism. As a result, oxacillin can be considered as an effective treatment for late-onset sepsis, making it possible to avoid broad-spectrum antibiotics.

Resumo Objetivo Comparar dois períodos com diferentes esquemas empíricos para tratamento de sepse neonatal tardia, incluindo vancomicina ou oxacilina respectivamente, em unidade neonatal de referência com alta prevalência de Staphylococcus coagulase negativo. Métodos Estudo transversal, feito em unidade neonatal de referência, de 2011 a 2014. Os dados foram coletados diariamente por vigilância ativa em prontuário de recém-nascidos de risco. As infecções foram notificadas conforme critérios definidos pela Agência Nacional de Vigilância Sanitária. O banco de dados e a análise foram feitos em programa interno. Resultados Ocorreu redução significativa da notificação de infecções por Staphylococcus aureus (p = 0,008), sem notificações de endocardite, meningite e infecções de vias aéreas inferiores, além de redução na frequência de óbitos pelo microrganismo e sem alteração significativa nas incidências de infecções por bactérias Gram negativas e fungos. Houve aumento de infecções S. aureus coagulase negativo (p = 0,022), mas sem aumento de morbidade e mortalidade. Ocorreu redução na mediana do tempo de uso de oxacilina, de 11,5 para 6 dias (p < 0,001), com aumento de mediana de um dia de uso de vancomicina (p = 0,046). Conclusões A modificação do esquema empírico com uso de oxacilina revelou redução significativa das infecções por S. aureus, além da redução na frequência de infecção de foco profundo e mortalidade pelo microrganismo. Considera-se que oxacilina pode ser usada como esquema de tratamento de sepse neonatal tardia para se evitar o uso de antibióticos de largo espectro.

Oxacillin disk diffusion testing for the prediction of penicillin resistance in Streptococcus pneumoniae / Prueba de difusión con discos de oxacilina para predecir la resistencia a la penicilina de Streptococcus pneumoniae

ABSTRACT Objective To 1) describe the correlation between the zones of inhibition in 1-µg oxacillin disk diffusion (ODD) tests and penicillin and ceftriaxone minimum inhibitory concentrations (MICs) of meningeal and non-meningeal strains of Streptococcus pneumoniae and 2) evaluate the usefulness of the ODD test as a predictor of susceptibility to penicillin in S. pneumoniae and as a quick and cost-effective method easily implemented in a routine clinical laboratory setting. Methods S. pneumoniae isolates from healthy nasopharyngeal carriers less than 2 years old, obtained in a multicentric cross-sectional study conducted in various Peruvian hospitals and health centers from 2007 to 2009, were analyzed. Using Clinical and Laboratory Standards Institute (CLSI) breakpoints, the correlation between the zones of inhibition of the ODD test and the MICs of penicillin and ceftriaxone was determined. Results Of the 571 S. pneumoniae isolates, 314 (55%) showed resistance to penicillin (MIC ≥ 0.12 µg/mL) and 124 (21.7%) showed resistance to ceftriaxone (MIC ≥ 1 µg/mL). Comparison of the ODD test zones of inhibition and the penicillin MICs, using the CLSI meningeal breakpoints, showed good correlation (Cohen’s kappa coefficient = 0.8239). Conclusions There was good correlation between ODD zones of inhibition and penicillin meningeal breakpoints but weak correlation between the ODD results and non-meningeal breakpoints for both penicillin and ceftriaxone. Therefore, the ODD test appears to be a useful tool for predicting penicillin resistance in cases of meningeal strains of S. pneumoniae, particularly in low- and middle- income countries, where MIC determination is not routinely available.

RESUMEN Objetivo 1) Describir la correlación entre las zonas de inhibición observadas en la prueba de difusión con discos de oxacilina de 1 µg y la concentración inhibitoria mínima (CIM) de penicilina y ceftriaxona frente a cepas meníngeas y no meníngeas de Streptococcus pneumoniae y 2) evaluar si la prueba de difusión con discos de oxacilina permite predecir la sensibilidad de S. pneumoniae a la penicilina y sirve como método rápido y eficaz en función de los costos, y resulta fácil de aplicar en los laboratorios clínicos ordinarios. Métodos Se analizaron colonias de S. pneumoniae aisladas de la nasofaringe de portadores sanos menores de 2 años obtenidas en un estudio transversal multicéntrico realizado en diversos hospitales y centros de salud del Perú entre los años 2007 y 2009. Se determinó la correlación entre las zonas de inhibición observadas en la prueba de difusión con discos y la CIM de la penicilina y la ceftriaxona utilizando los valores críticos definidos por el Instituto de Estándares Clínicos y de Laboratorio. Resultados De las 571 colonias aisladas de S. pneumoniae, 314 (55 %) presentaron resistencia a la penicilina (CIM ≥ 0,12 µg/ml) y 124 (21,7%), resistencia a la ceftriaxona (CIM ≥ 1 µg/ml). Se observó una buena correlación (coeficiente κ de Cohen = 0,8239) entre las zonas de inhibición de la prueba de difusión con discos y la CIM de la penicilina utilizando los valores críticos del Instituto respecto de las cepas meníngeas. Conclusiones Se encontró una buena correlación entre las zonas de inhibición de la prueba de difusión con discos y los valores críticos de CIM de la penicilina respecto de las cepas meníngeas, pero una correlación débil entre los resultados de la prueba de difusión y los valores críticos tanto de la penicilina como de la ceftriaxona respecto de las cepas no meníngeas. Por consiguiente, la prueba de difusión con discos es un método de utilidad para predecir la resistencia a la penicilina de las cepas meníngeas de S. pneumoniae, en particular en los países de ingresos bajos y medianos, donde no suele ser posible determinar la CIM.

Staphylococcus aureus and the oxacillin sensitivity profile in hospitalized people with HIV/AIDS / Staphylococcus aureus y el perfil de sensibilidad a la oxacilina en personas viviendo con vih/sida hospitalizadas / Staphylococcus aureus e o perfil de sensibilidade à oxacilina em pessoas vivendo com HIV/aids hospitalizadas

Abstract Objective Analyze nasal colonization by oxacillin-sensitive and oxacillin-resistant Staphylococcus aureus in people with HIV/AIDS (PWHA) at days 1 and7 of hospitalization. METHOD A prospective observational study conducted in a hospital in the countryside of the state of São Paulo. Nasal swab samples were collected and analyzed through microbiological identification, at days 1 and 7 of hospitalization of PWHA, between August 2011 and January 2014. Data were analyzed via IBM SPSS(r), version 20.0. RESULTS Nasal secretion samples were collected from 187 (50.1%) PWHA at days 1 and 7 of hospitalization. Of these, Staphylococcus aureus was identified in 64 (34.2%) PWHA. CONCLUSION At day 1 of hospitalization, 27 PWHA were identified with Staphylococcus aureus; 27 PWHA presented colonization by Staphylococcus aureus at days 1 and 7, and 10 PWHA only at day 7. Of 64 PWHA colonized by Staphylococcus aureus, the susceptibility profile of isolated Staphylococcus aureus was oxacillin-resistant in 25 PWHA.

Resumen OBJETIVO Analizar la colonización nasal por Staphylococcus aureus sensibles y resistentes a la oxacilina de personas viviendo con VIH/Sida (PVVS) el primer y séptimo día de estancia hospitalizar. MÉTODO Estudio prospectivo observacional, realizado en un hospital del interior del Estado de São Paulo. Fueron recogidas y analizadas, mediante identificación microbiológica, muestras de swab nasal el primer y el séptimo día de estancia hospitalaria de PVVS, en el período de agosto/2011 a enero/2014. Se realizó el análisis de los datos mediante el IBM SPSS(r), versión 20.0. RESULTADOS En 187 (50,1%) PVVS, fueron recogidas muestras de secreción nasal el primer y séptimo día de estancia hospitalaria. De esas, en 64 (34,2%) fue identificado Staphylococcus aureus. CONCLUSIÓN El primer día de estancia se observó 27 PVVS colonizadas por Staphylococcus aureus; en 27 PVVS hubo la persistencia de la colonización por Staphylococcus aureus el primer y el séptimo día; en 10 PVVS, solo el séptimo día. De las 64 PVVS colonizadas por Staphylococcus aureus, en 25 el perfil de susceptibilidad del Staphylococcus aureus aislado fue resistente a la oxacilina.

Resumo OBJETIVO Analisar a colonização nasal por Staphylococcus aureus sensíveis e resistentes à oxacilina de pessoas vivendo com HIV/aids (PVHA) no primeiro e no sétimo dia de internação hospitalar. MÉTODO Estudo prospectivo observacional realizado em um hospital do interior paulista. Foram coletadas e analisadas, por meio de identificação microbiológica, amostras de swab nasal no primeiro e no sétimo dia de internação hospitalar de PVHA, no período de agosto/2011 e janeiro/2014. A análise dos dados foi realizada por meio do IBM SPSS(r), versão 20.0. RESULTADOS Em 187 (50,1%) PVHA foram coletadas amostras de secreção nasal no primeiro e sétimo dia de internação. Destas, em 64 (34,2%) foi identificado Staphylococcus aureus. CONCLUSÃO No primeiro dia de internação observou-se 27 PVHA colonizadas por Staphylococcus aureus; em 27 PVHA houve a persistência da colonização por Staphylococcus aureus no primeiro e no sétimo dia; em 10 PVHA, somente no sétimo dia. Das 64 PVHA colonizadas por Staphylococcus aureus, em 25 o perfil de suscetibilidade do Staphylococcus aureus isolado foi resistente à oxacilina.

Staphylococcus aureus con resistencia múltiple a los antibióticos (MDR) en un Hospital de Maracaibo- Venezuela / Multidrug-resistant (MDR) Staphylococcus aureus in a Maracaibo’s hospital, Venezuela

Staphylococcus aureus resistente a oxacilina (SAOR) continúa siendo una causa importante de infecciones nosocomiales en todo el mundo. Se determinó la resistencia a los antibióticos de cepas intrahospitalarias, clasificándolas en multidrogo-resistentes, extensamente drogo-resistentes o pandrogo-resistentes. Las muestras biológicas fueron recolectadas entre septiembre 2013-febrero 2014 y procesadas de acuerdo a técnicas de bacteriología convencional. La resistencia a los antibióticos se determinó mediante el método de difusión con discos en agar y el gen mecA se detectó mediante reacción en cadena de la polimerasa. Se observó baja prevalencia de SAOR intrahospitalario (13,86%). La mayor resistencia fue a eritromicina (66,07%), mientras que la resistencia frente a aminoglucósidos, fluoroquinolonas, clindamicina y tetraciclina fue inferior al 25%; la resistencia frente a trimetoprim/sulfametoxazol fue muy baja y el 100% de las cepas mostraron sensibilidad a rifampicina, linezolid, vancomicina y teicoplanina. El fenotipo de resistencia a MLSB más frecuente fue el de resistencia a eritromicina y susceptibilidad a clindamicina (33,93%, fenotipo MSB). Las cepas SAOR aisladas presentaron 25 antibiotipos diferentes, siendo la mayoría de los aislamientos multidrogo-resistentes (55,36%). No se observó resistencia extensa a los antibióticos ni pandrogo-resistencia y la presencia del gen mecA se demostró en todos los aislamientos resistentes a oxacilina.

Oxacillin-resistant Staphylococcus aureus (ORSA) has remained a major cause of nosocomial infections worldwide. The antibiotic resistance of isolations was determined and we classify them in multidrug-resistant, extensively drug-resistant or pandrug-resistant. The biological samples of patients from a Maracaibo’s Hospital, during September 2013 to February 2014, were processed according to conventional techniques of bacteriology. Antibiotic resistance was determined by disk diffusion method in agar and the mecA gene was detected by polymerase chain reaction. It was observed a low prevalence of nosocomial ORSA (13.86%). The higher antibiotic resistance was observed against erythromycin (66.07%) and a resistance lower than 25% to aminoglycosides, fluoroquinolones, tetracycline and clindamycin. The isolates showed a very low resistance to trimethoprim/sulfamethoxazole and all isolates were susceptible to rifampicin, linezolid, vancomycin and teicoplanin.The majority of isolates had a MSB phenotype (33.93%), with erythromycin resistance and susceptibility to clindamycin. The ORSA isolates in this study had 25 different antibiotypes and the majority of them were multidrug-resistant (55.36%). There was not both extensively drug-resistant and pandrug-resistant isolates and the presence of the mecA gene was demonstrated in all isolates of ORSA.

Empirical antimicrobial therapy for late-onset sepsis in a neonatal unit with high prevalence of coagulase-negative Staphylococcus.

OBJECTIVE: The aim of this study was to compare two different empiric treatments for late-onset neonatal sepsis, vancomycin and oxacillin, in a neonatal intensive care unit with a high prevalence of coagulase-negative Staphylococcus. METHODS: A cross-sectional study was conducted in an neonatal intensive care unit from 2011 to 2014. Data from the medical records of at-risk newborns were collected daily. Infections were defined according to the National Health Surveillance Agency criteria. Data analysis was performed using an internal program. RESULTS: There was a significant reduction in the number of Staphylococcus aureus infections (p=0.008), without endocarditis, meningitis, or lower respiratory tract infection, as well as a reduction in the frequency of deaths related to S. aureus infection. There were no significant changes in the incidence of Gram-negative bacterial or fungal infections. An increase in coagulase-negative Staphylococcus infections was observed (p=0.022). However, there was no measured increase in related morbidity and mortality. There was a reduction in the median number of days of treatment with oxacillin from 11.5 to 6 days (p<0.001) and an increase of one day in the median number of days of treatment with vancomycin (p=0.046). CONCLUSIONS: Modification of the empiric treatment regimen for neonatal late-onset sepsis with use of oxacillin showed a significant reduction in S. aureus infections, as well as a reduction in the frequency of infections with major organ system involvement and mortality due to infection with this microorganism. As a result, oxacillin can be considered as an effective treatment for late-onset sepsis, making it possible to avoid broad-spectrum antibiotics.

Correlación entre la detección de superantígenos y resistencia a oxacilina en aislamientos hospitalarios de Staphylococcus aureus / Correlation between detection of superantigens and oxacillin resistance of Staphylococcus aureus in hospital isolates

Objetivo: Establecer la correlacion entre la deteccion de superantigenos (MSSA) y la susceptibilidad a oxacilina de Staphylococcus aureus (MRSA) en aislamientos hospitalarios. Materiales y métodos: En 81 aislamientos de Staphylococcus aureus de origen hospitalario, la susceptibilidad a oxacilina se establecio por un sistema automatizado y la deteccion de 22 genes de superantigenos fue realizada mediante PCR individual y multiple. Resultados: La MRSA fue del 38,3%. Todos los aislamientos MRSA portaban uno o mas genes de superantigenos; y el 92% de MSSA. El numero de genotipos fue variable, pero un hallazgo relevante fue que el cluster egc solo fue detectado en MRSA (48,4%). Los genes no clasicos mas detectados en MRSA fueron sem (53,1%) y seg (28,4%); y sem (37%) y seq (30,9%) para MSSA. El gen sec clasico (13,6%) fue mas prevalente en MSSA, y en MRSA, los clasicos fueron de muy baja frecuencia. Para todos los genes, los genes seg , sej , sen , seo y seq mostraron diferencias estadisticamente significativas entre los aislamientos MRSA y MSSA. Conclusión: Este estudio no permitio sacar conclusiones concluyentes para establecer la relacion entre la deteccion de superantigenos y la susceptibilidad a oxacilina (MRSA vs. MSSA). Aunque, el numero de genotipos fue variable, la presencia del cluster egc solamente en aislamientos MRSA es un hallazgo interesante, y en posteriores estudios se podria determinar la importancia del cluster egc.

Objective: To establish the relationship between the detection of superantigens (MSSA) and Staphylococcus aureus resistance to oxacillin in hospital isolates. Material and methods: In 81 isolates of Staphylococcus aureus of hospital origin, an oxacillin susceptibility test was performed by an automated system and 22 superantigenic genes were obtained using single and multiplex PCR. Results: The MRSA was 38.3%. All MRSA isolates carried one or more genes for superantigens and 92.0% of MSSA. The numbers of genotypes for the 2 groups were variable, but the most important finding was that the egc cluster was detected only in MRSA (48.4%). The non-classic genes more often detected in MRSA were sem (53.1%) and seg (28.4%); in MSSA they were sem (37.0%) and seq (30.9%). The gen classic sec (13.6%) was more prevalent in MSSA and in MRSA; the classic genes were very low in frequency. For all genes, the genes: seg , sej , sen , seo and seq showed statistically significant differences between MRSA and MSSA isolates. Conclusion: This study did not reveal a clear relationship between the detection of superantigens and oxacillin susceptibility (MRSA vs. MSSA). Although the number of genotypes varied, the presence of egc cluster only in the MRSA isolate was an important finding. Further studies are needed to establish the importance of the egc cluster.

Caracterização de Staphylococcus aureus isolados da barra de mão de carrinhos e alças de cestas de supermercados / Characterization of Staphylococcus aureus Isolated of shopping carts hand bars and handles of handheld shopping baskets in supermarkets

Staphylococcus aureus é um dos agentes patogênicos mais notórios, sendo responsável por 45% das toxinfecções em todo o mundo. Um dos grandes problemas atuais é o desenvolvimento de cepas resistentes a antibióticos. Considerando a importância da disseminação desses micro-organismos na comunidade, o presente trabalho teve por objetivo determinar a presença de Staphylococcus aureus na barra de mão dos carrinhos e alças de cestas de supermercados da cidade de Campo Mourão - PR, e caracterizar a susceptibilidade dos isolados à oxacilina. Foram analisadas 120 amostras, sendo 60 coletadas das barras de mão de carrinhos e 60 coletadas das alças de cestas. Esse micro-organismo foi isolado em 75 amostras (62,5%), sendo que, desse total, 35 amostras (46,7%) foram isoladas de carrinhos e 40 (53,3%) de cestas de compras. As amostras positivas para Staphylococcus aureus foram submetidas aos testes de susceptibilidade, pelo método de disco-difusão, à oxacilina (cefoxitina) e todas as amostras foram consideradas sensíveis a essa droga. Constatou que as barras de mãos e as alças de cestas de supermercados, podem ser consideradas como fômites, na disseminação de Staphylococcus aureus, sendo de extrema importância a higienização desses objetos, a fim de diminuir os riscos de contaminação na comunidade.

Staphylococcus aureus is one of the most notorious pathogens, accounting for 45% of intoxications worldwide. One of the major problems today is the development of antibiotic-resistant strains. Considering the importance of dissemination of these microorganisms in the community, this study aimed to determine the presence of Staphylococcus aureus in shopping carts hand bars and handles of handheld shopping baskets in supermarkets from the city of Campo Mourão ­ PR, and characterize the susceptibility of isolates to oxacillin. One hundred twenty samples, of which 60 collected from bars hand stands and collected 60 of the handles of baskets. This micro-organism was isolated in 75 samples (62.5%), and of this total, 35 samples (46,7%) were isolated from carts and 40 (53,3%) of shopping baskets. The positive samples for Staphylococcus aureus were submitted to susceptibility testing by the disk diffusion method to oxacillin (cefoxitin) and all samples were found to be sensitive to this drug. It found that the bars of hands and the handles of supermarket baskets can be considered as fomites in the dissemination of Staphylococcus aureus, being extremely important to sanitization these objects in order to reduce the risk of contamination in the community.

Evaluación del cocimiento de diferentes biovariedades de Caesalpinia spinosa (tara) frente a cepas de Staphylococcus aureus sensibles y resistentes a oxacilina / Evaluation of different biovarieties of Caesalpinia spinosa (tara) poaching against oxacillin sensitive and resistant Staphylococcus aureus strains

Objetivos: Comprobar la actividad antimicrobiana de tres biovariedades de tara frente a cepas de Staphylococcus aureus sensibles y resistentes a oxacilina. Diseño: Estudio descriptivo, prospectivo, analítico. Institución: Instituto de Medicina Tropical Daniel A. Carrión, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Tres biovariedades de tara y cepas de Staphylococcus aureus. Intervenciones: Se evaluó 31 cepas de S. aureus oxacilina sensibles y 29 resistentes, aislados de muestras clínicas, frente a tres cocimientos de tara de las zonas de Huamanga, Huarochirí y Tarma. Se preparó el cocimiento de tara y se impregnó discos en blanco para utilizarlos como un antibiograma por disco difusión. Principales medidas de resultados: Diámetro de los halos de inhibición. Resultados: Los tres cocimientos presentaron actividad antimicrobiana frente a las cepas de Staphylococcus aureus; el cocimiento de Huamanga presentó mayor halo de inhibición frente a cepas sensibles y resistentes. El cocimiento de Huarochirí mostró mayor halo de inhibición en cepas oxacilino resistentes que sensibles; la diferencia fue significativa. El cocimiento de Huarochirí tuvo una actividad menor y fue significativa, frente a los cocimientos de Huamanga y Tarma. Conclusiones: El cocimiento de Huarochirí presentó menor actividad que los de Huamanga y de Tarma...

Objectives: To determine three taraÆs biovarieties antimicrobial activity against oxacillin sensitive and resistant Staphylococcus aureus strains. Design: Descriptive, prospective, analytical study. Setting: Instituto de Medicina Tropical Daniel A. Carrion, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Peru. Biologic material: Three tara biovarieties and Staphylococcus aureus strains. Interventions: Thirty-one S. aureus oxacillin-sensitive strains and 29 oxacillin-resistant strains isolated from clinical samples were studied against three tara varieties obtained in Huamanga, Huarochiri and Tarma. TaraÆs poaching was prepared and blank discs were soaked in to use as antibiogram by disc difussion. Main outcome measures: Inhibition halos diameter. Results: All three poachings showed antimicrobial activity against Staphylococcus aureus strains; HuamangaÆs poaching displayed larger inhibition halo against sensitive and resistant strains. HuarichiriÆs poaching showed significant larger inhibition halo in oxacillin-resistant strains than in sensitive ones. HuarochiriÆs poaching had less significant activity as compared with Huamanga and Tarma poachings. Conclusions: HuarochiriÆs poaching exhibited less activity compared with those from Huamanga and Tarma...

Incidência de bacteriemia em um hospital terciário do leste de Minas Gerais / Incidence of bacteremia in a tertiary hospital in eastern Minas Gerais

Objetivos: determinar a incidência e a prevalência bacteriana em hospital da região leste do estado de Minas Gerais, bem como verificar a sensibilidade dos microrganismos aos antibióticos disponíveis para terapia. Métodos: o estudo é retrospectivo, com análise de prontuários médicos e resultados das hemoculturas dos pacientes submetidos a esse exame no período de 1º. de janeiro a 31 de dezembro de 2010. A avaliação da significância da infecção foi feita a partir das manifestações clínicas dos pacientes submetidos à hemocultura, evitando, assim, amostras contaminantes. Resultados e discussão: das 344 hemoculturasestudadas, correspondendo a 344 pacientes, evidenciaram-se crescimento e não crescimento bacteriano em 64 (18,6%) e em 280 (81,4%) casos, respectivamente. A espécie Staphylococcus epidermidis mostrou-se mais prevalente na causa de bacteriemias - 40,6% dos casos -, como ocorre em outras descrições de estudos nacionais e internacionais. Observou-se que 15,4% das infecções por S. epidermidisdetectadas no hospital de Caratinga eram sensíveis à oxacilina. Conclusão: o S. epidermidis é o principal agente responsável pelas infecções sanguíneas, o que está, provavelmente, relacionado ao uso crescente de cateter venoso e ao estado de imunossupressão desenvolvido pelos pacientes com internações prolongadas; e apresenta elevada resistência à oxacilina, exigindo cuidado com o uso indiscriminadode antibióticos.

Objectives: To determine bacterial incidence and prevalence in a hospital in eastern Minas Gerais, as well as to verify the sensitivity of microorganisms to antibiotics available for therapy. Methods: This study is a retrospective analysis of medical records and blood culture results of patients from January 1st to December 31st, 2010. Infection significance was assessed based on the clinical manifestations of patients who underwent blood culture, thus avoiding sample contamination. Results anddiscussion: of 344 blood cultures studied, corresponding to 344 patients, bacterial growth was found in 64 (18.6%) cases and non-bacterial growth in 280 (81.4%) cases. Staphylococcus epidermidis was more prevalent as the cause of bacteriemia - 40.6% of the cases - similarly to what has been observed in other national and international studies. We found that 15.4 % of infections caused by S. epidermidis detected in the hospital in Caratinga were sensitive to oxacillin. Conclusions: S. epidermidis is the main agent responsible for blood infections. This is probably related to the increased use of venous catheters and to the status of immunosuppression developed by patients in prolonged hospitalizations. This species is highly resistant to oxacillin, which demands attention to prevent the indiscriminate use of antibiotics.

Relação entre a resistência a oxacilina e a produção de biofilme de amostras de origem comunitária e hospitalar pertencentes a diferentes espécies de Staphylococcus coagulase negativo / Relationship between resistance to oxacillin and biofilm production samples of Community and hospital belonging to different species of coagulase-negative Staphylococcus

Nas últimas décadas, os Staphylococcus coagulase-negativo, têm sido considerados como patógenos verdadeiros, sendo um dos principais grupos bacterianos responsáveis pelas infecções relacionadas a assistência a saúde (IRAS). O presente estudo teve como objetivo geral: avaliação da relação entre a resistência a oxacilina e a produção de biofilme de amostras Staphylococcus coagulase-negativo de origem comunitária e hospitalar. Neste sentido, foram desenvolvidos os seguintes objetivos específico: identificar ao nível de espécie os Staphylococcus coagulase-negativo; analisar por técnica fenotípica (Ágar vermelho do Congo) a produção de slime; avaliar quantitativamente, a produção de biofilme; correlacionar a produção de polissacarídeos extracelulares (slime) com a produção de biofilme; avaliar a relação da resistência a oxacilina como indicador da presença do gene mecA; avaliar a relação entre a concentração inibitória mínima e a concentração bactericida mínima para oxacilina; pesquisar a presença dos genes mecA, icaAD e atlE, pela técnica de PCR. Foi estudado um total de 150 amostras, sendo 50 isoladas de fômites, 50 isoladas de sangue e 50 isoladas de comunidade. Independente da origem, foram identificadas 14 espécies de Staphylococcus coagulase-negativo, sendo mais frequentes S. epidermidis 42,6%, S. haemolyticus 13,3% e S. cohnii cohnii 10,7%. A análise geral da expressão fenotípica de slime mostrou que 64% das amostras avaliadas eram produtoras de slime. Das 150 amostras testadas neste estudo, 95,3% foram produtoras de biofilme. Ao considerarmos a análise da quantificação do biofilme em relação às origens das amostras estudadas não encontramos diferenças significativas e a maioria das amostras foi considerada moderadamente produtora de biofilme. O gene mecA foi detectado em 6 amostras comunitárias, 34 amostras de fômites e 34 amostras de sangue. Não houve diferença significativa entre as amostras de fômites e sangue...

In recent decades, coagulase-negative Stapphylococci have been considered as true pathogen, one of the major bacterial groups responsible for hospital infection. The present study aimed to: assess the relationship between oxacillin resistance and biofilm production samples coagulase-negative Stapphylococci of community and hospital. In this sense, we have developed the following specific objectives: to identify to species level coagulase-negative Staphylococci; analyze by phenotypic test (Congo red Agar) slime production, evaluate quantitatively the biofilm production; correlate the production of extracellular polysaccharides (slime) with biofilm production; evaluate the relationship of resistance to oxacillin as an indicator of the presence of the mecA gene; evaluate the relationship between minimal inhibitory concentration and minimum bactericidal concentration for oxacillin; investigate the presence of the mecA gene, atlE and icaAD, by PCR. We studied a total of 150 samples, 50 were isolated from fomites, 50 from community and 50 isolated from blood. Regardless of origin, 14 species of coagulase-negative Stapphylococci were identified , being more frequent 42.6% S.epidermidis, 13.3% S. haemolyticus and 10.7% S. cohnii cohnii. A general analysis of the phenotypic expression of slime showed that 64% of the samples were slime producers...

Infecciones osteoarticulares en la edad pediátrica: artritis séptica: cuatro años de evolución / Osteoarticular infections in children: septic arthritis: four years of follow

La artritis séptica ocurre ocurre por invasión de bacterias a una articulación y si no son diagnosticadas y tratadas a tiempo producen elevada incidencia de secuelas y discapacidad, por lo que son consideradas una urgencia médico-quirúrgicas. Considerando la importancia de esta patología en la edad pediátrica, se realizó un estudio retrospectivo, descriptivo en pacientes con diagnóstico de infección osteoarticualar para evaluar características clínicas, microbiológicas y terapéuticas en el Hospital Universitario de Pediatría "Agustín Zubillaga" entre enero 2008 y marzo 2011. Se revisaron 35 expedientes, encontrándose que la artritis séptica representó 54,2% siendo más frecuente en el sexo masculino en 57,8%. Prodominó en lactantes y escolares con 26,3% respectivamente. La articulación de la cadera fue la más afectada en 52,6%. En 21% de casos se refirió traumatismo de partes blandas como antecedentes. La ecografía de partes blandas fue diagnóstica en 94,7%. Se realizó hemocultivos al 52,6%de casos, de los cuales 80% reportó sin desarrollo bacteriano y en 20% se aisló S. aureus sensibles a meticilina. Las muertes de secreación articular fueron positivas en 50% de los casos, de estos 71,4% correspondió a S. aureus, y 14,3% a Enterobacter sp. El 73,6% recibió oxacilina de inicio siendo necesario el cambio del mismo en un 63,1%. Las infecciones ostearticulares requieren un alto grado de sospechas clínicas por lo que se deben mejorar los procedimientos diagnósticos, a fin de lograr el rápido inicio de la terapéutica antimicrobiana y los procedimientos quirúrgicos adecuados para disminuir el riesgo de secuelas.

Septic arthritis occurs by bacterial invasion of a joint, if it is not diagnosed and treated at time produces a high incidence of sequelae and disabilities, which are considered a medical-surgical emergency. Considering the importance of this disease in children, we conducted a retrospective, descriptive study in patients with osteo-articular infection to assess clinical, microbiological and therapeutic characteristics of these infections in the University Hospital of Pediatrics "Agustic Zubillaga" between January 2008 and March 2011. 35 records were reviewed and we founded septic arthritis to account for 54,2% of them, being more frequent in males (57,8%). It predominated in infants and school age patients with 26,3% respectively. Hip joint was the most affected one in 52,6% of the cases. In 21% of the cases it was involved a soft-tissue injure as an antecedent. Ultrasound of soft tissue was the cause of diagnosis in 94,7% of the cases. Blood culture was performed to 52,6% of case , of which 80% reported no bacterial growoth, and in 20% of them, it was isolated methcillin sensible S. aureus. Articular secretion samples were positive in 50% of cases, 71,4% of these corresponding to S. aureus, and 14,3% to Enterobacter sp. Around 73,6% of patients received oxacillin as a first therapy, and in 63,1% of them therapy must have to be changed. Ostearticular infection requiere a high degree of clinical suspicion, in order to achieve rapid onset of antimicrobial therapy and appropriate surgical procedures to reduce the risk of sequelae.

Caracterização do cassete cromossômico mec (SCCmec) e análise fenótípica e molecular de resistência a oxacilina em estafilococos coagulase-negativa e Staphylococcus aureus / Characterization of chromosomal cassete mec (SCCmec) analysis and molecular an phenotypic oxacillin in coagulase-negative staphylococci and staphylococcus aureus

Os estafilococos coagulase negativa são patógenos associados a infecções nosocomiais, principalmente bacteremia e sepse. A oxacilina é uma das alternativas de escolha no tratamento das infecções causadas por Staphylococcus spp., contudo, a resistência a esta droga têm se tornado um grande problema nas últimas décadas. O objetivo deste estudo foi caracterizar a sensibilidade à oxacilina em amostras de ECN isoladas de pacientes do Hospital das Clínicas (HC) da Faculdade de Medicina de Botucatu (FMB) por diferentes métodos, determinar a concentração inibitória mínima a antimicrobianos, a triagem de amostras com sensibilidade intermediária à vancomicina e a caracterização do perfil clonal de amostras de MRCoNS isoladas de hemoculturas. Um total de 160 amostras foram analisadas quanto a resistência à oxacilina por meio da técnica de difusão da droga em ágar com disco de oxacilina e cefoxitina, teste de triagem em Ágar Mueller-Hinton com 4 μg/mL de oxacilina e 4% de NaCl, E-test, detecção do gene mecA, e determinação da sensibilidade intermediária a vancomicina em ágar BHI com 4 μg/mL e com 6 μg/mL de vancomicina, além da caracterização do perfil epidemiológico pela tipagem do cassete cromossômico mec (SCCmec) e análise clonal por PFGE de 59 amostras de S. epidermidis e 07 amostras de S. haemolyticus isoladas no período de 2002 a 2009. Um total de 74,4% das amostras foram positivas para o gene mecA. A sensibilidade do método de difusão com disco de oxacilina e da técnica de E-test foi de 99,1% e com especificidade de 90,1%. O disco de cefoxitina apresentou 100% de sensibilidade e a mesma especificidade descrita para o disco de oxacilina. O método de triagem apresentou 94,2% de sensibilidade e a melhor taxa de especificidade com 93,2%. Houve diferença entre as amostras MRCoNS...

Oxacillin is one of the alternatives of choice in the treatment of infections caused by Staphylococcus spp. However, resistance to this drug has become a major problem in recent decades. The aim of this study was to characterize the sensitivity to oxacillin in CNS samples isolated from patients at the School of Medicine University Hospital (HCFMB) - UNESP by different methods, to determine antimicrobial minimum inhibitory concentration, the screening of samples with intermediate sensitivity to vancomycin and characterization of the clonal profile of MRCoNS samples isolated from blood cultures. A total of 160 samples were analyzed for resistance to oxacillin by the drug diffusion technique in agar with oxacillin and cefoxitin, a screening test on Mueller-Hinton agar with 4 μg/mL of oxacillin and 4% NaCl, E-test, mecA gene detection, and determination of intermediate susceptibility to vancomycin in BHI agar with 4 μg/mL and 6 μg/mL of vancomycin, and characterizing the epidemiological profile by typing the cassette chromosome mec (SCCmec) and clonal analysis by PFGE a total of 59 samples of S. epidermidis and 07 samples of S. haemolyticus isolated in the period 2002 to 2009. A total of 74.4% of the samples were positive for mecA. The sensitivity of the oxacillin disk diffusion and E-test technique was 99.1% and specificity 90.1%. The cefoxitin disk showed 100% sensitivity and specificity reported for the same oxacillin disc. The screening method showed 94.2% sensitivity and specificity with the best rate of 93.2%. There were differences between samples when analyzed MSCoNS MRCoNS and the minimum inhibitory concentration (MIC), with higher levels of MIC in the group MRCoNS, and higher rates of multidrug resistance. None of the samples showed resistance or heteroresistant to vancomycin, however, 10 samples grown...