Detection and genotyping of human respiratory viruses in clinical specimens from children with acute respiratory tract infections.

Respiratory virus infections are a major health concern and represent the primary cause of testing consultation and hospitalization for young children. The application of nucleic acid amplification technology, particularly multiplex PCR coupled with fluidic or fixed microarrays, provides an important new approach for the detection of multiple respiratory viruses in a single test. The aim of this study was to analyze respiratory samples from children with acute respiratory tract infection (ARTI) using a commercial array-based method (CLART(®) PneumoVir Genomica, Coslada, Spain). These tests were used to identify viruses in 281 nasopharyngeal samples obtained from children affected by ARTI. Samples were obtained form October 2008 to April 2009. Viruses were identified in 80% of the studied ARTI providing useful information on clinical features and epidemiology of specific agents affecting children in cold months. Multiple viral infections were found in 33.45% of the specimens.

Rapid diagnosis of invasive pneumococcal disease in pediatric population.

The aim of this study was to evaluate the Binax NOW immunochromatographic pneumococcal antigen test for the identification of Streptococcus pneumoniae in pleural and cerebrospinal fluids from children with suspected invasive pneumococcal disease. The results were compared with those obtained by PCR. Binax NOW was applied to these samples as recommended by the manufacturer for urine and cerebrospinal samples. Detection of pneumococcal DNA was performed by real-time PCR assay targeting the autolysin gene (lytA). Of the 199 samples analyzed, 131 were positive by both Binax NOW and lytA PCR, and 36 samples were negative by both techniques. Using the real-time PCR as a comparative method to the Binax for the detection of S. pneumoniae, the sensitivity and specificity of Binax NOW was 88% and 72.5%, respectively. Of the 145 positive samples analyzed by Binax NOW, 119 showed intense coloring of the sample line and 26 showed weak intensity. Conventional culture is the most common method in clinical settings, but Binax NOW is an easier and faster test for identifying S. pneumoniae in pleural and cerebrospinal fluids from children with suspected invasive pneumococcal disease.

Detection and genotyping of human respiratory viruses in clinical specimens from children with acute respiratory tract infections

Las infecciones por virus respiratorios representan la primera causa de consulta y hospitalización en la población pediátrica. El empleo de técnicas moleculares, principalmente aquellas basadas en PCR múltiple acoplada a detección por microarrays, supone un importante avance para la detección de varios de estos virus en un único ensayo. El objetivo de este estudio ha sido el análisis de muestras respiratorias procedentes de niños con infección respiratoria aguda (ARTI) mediante un método comercial (CLART® PneumoVir). Este método se basa en la amplificación y detección por microarrays de los 17 virus humanos más frecuentes en este tipo de patología. El ensayo se ha llevado a cabo en 281 muestras nasofaríngeas provinientes de niños con ARTI que acudieron al Hospital Clínico San Carlos de Madrid entre Octubre del 2008 y Abril del 2009. El 80% de las muestras estudiadas presentaron un resultado positivo para, al menos, uno de los 17 virus analizados proporcionando una valiosa información sobre las características clínicas y epidemiológicas de los agentes específicos que afectan a la población pediátrica en los meses fríos. Gracias a la técnica empleada pudieron detectarse infecciones múltiples en el 33,45% de las muestras(AU)

Respiratory virus infections are a major health concern and represent the primary cause of testing consultation and hospitalization for young children. The application of nucleic acid amplification technology, particularly multiplex PCR coupled with fluidic or fixed microarrays, provides an important new approach for the detection of multiple respiratory viruses in a single test. The aim of this study was to analyze respiratory samples from children with acute respiratory tract infection (ARTI) using a commercial array-based method (CLART® PneumoVir Genomica, Coslada, Spain). These tests were used to identify viruses in 281 nasopharyngeal samples obtained from children affected by ARTI. Samples were obtained form October 2008 to April 2009. Viruses were identified in 80% of the studied ARTI providing useful information on clinical features and epidemiology of specific agents affecting children in cold months. Multiple viral infections were found in 33.45% of the specimens(AU)

In vitro activity of tedizolid (TR-700) against linezolid-resistant staphylococci.

OBJECTIVES: To compare the activity of tedizolid (formally known as torezolid and TR-700) with that of 15 agents against a collection of linezolid-resistant staphylococci (164 coagulase-negative staphylococci and 5 Staphylococcus aureus). METHODS: Antimicrobial susceptibility tests were performed using the broth microdilution method following the recommendations of the CLSI. RESULTS: All isolates were susceptible to vancomycin and tigecycline. Based on the MIC(90) values, the potency of tedizolid against coagulase-negative staphylococci was >16-fold greater than that of linezolid. Tedizolid retained activity against most of the linezolid-resistant staphylococci tested, including multidrug-resistant isolates with elevated linezolid MICs (32 to >128 mg/L). Of the isolates, 79.2% and 31.4% were inhibited by tedizolid at ≤ 4 mg/L and ≤ 2 mg/L, respectively. CONCLUSIONS: The results of this study confirm the activity of tedizolid against linezolid-resistant staphylococci. This new oxazolidinone could have an important role as a potential therapeutic agent against multidrug-resistant staphylococci.

Rapid identification of clinical isolates of Bacteroides species by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry.

The objective of this study was to compare MALDI-TOF MS and Rapid ID 32A with 16S rRNA gene sequencing, the reference method for identification of Bacteroides species. Results show that MALDI-TOF MS can be a good option for identification of Bacteroides species, especially if the database is expanded.

Comparative activities of daptomycin and several agents against staphylococcal blood isolates. Glycopeptide tolerance.

The activity of daptomycin was evaluated against 702 staphylococcal blood isolates (316 methicillin-susceptible Staphylococcus aureus, 187 methicillin-resistant S. aureus [MRSA], and 199 coagulase-negative staphylococci [CoNS]) collected in 41 Spanish hospitals. Glycopeptide tolerance and the incidence of heterogeneous glycopeptide-intermediate (hGISA) isolates were also examined. Vancomycin MICs determined by the Etest were compared with those obtained by the reference broth microdilution method. Daptomycin exhibited good activity, and only 2 isolates were nonsusceptible to this antibiotic. Resistance to linezolid was observed in 2 MRSA isolates and in 16 CoNS. The cfr gene was detected in 7 of these 18 isolates. Vancomycin and teicoplanin tolerance was 9.6% and 21.9%, respectively, in MRSA isolates. We detected the hGISA phenotype in 5.8% of MRSA isolates. Vancomycin MICs by the Etest were slightly higher than those obtained by broth microdilution. Daptomycin retained activity against isolates that were not susceptible to linezolid, teicoplanin, or quinupristin-dalfopristin.

[Methicillin-resistant Staphylococcus aureus: changes in the susceptibility pattern to daptomycin during a 10-year period (2001-2010)]. / Staphylococcus aureus resistente a meticilina: sensibilidad a la daptomicina a lo largo de un periodo de 10 años (2001-2010).

INTRODUCTION: The objective of this study was to evaluate the activity of daptomycin and other agents against methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from 2001 to 2010, in order to determine changes and to detect resistance trends. METHODS: The study included a total of 1,130 MRSA isolates collected as part of a multicenter surveillance program for antibiotic resistance, Estudio de Vigilancia de Resistencia a los Antimicrobianos (VIRA study), from 51 medical centers throughout Spain between 2001 and 2010. Broth microdilution test was performed according to the Clinical Laboratory Standards Institute guidelines. RESULTS: Daptomycin showed excellent activity and maintained its activity over time; only one MRSA isolate collected in 2001 was nonsusceptible to this agent (MIC=2 mg/L). Based on the MIC90, daptomycin was 2-4 dilutions more active than vancomycin, teicoplanin and linezolid. Daptomycin retained activity against MRSA isolates that were resistant to linezolid, to quinupristin-dalfopristin, or showed intermediate susceptibility to vancomycin. CONCLUSIONS: Our data and those of other studies, coupled with daptomycin's rapid bactericidal activity, suggest that this antimicrobial could be an alternative in the treatment of severe infections caused by multiresistant S. aureus.

Staphylococcus aureus resistente a meticilina: sensibilidad a la daptomicina a lo largo de un periodo de 10 años (2001-2010) / Methicillin-resistant Staphylococcus aureus: changes in the susceptibility pattern to daptomycin during a 10- year period (2001-2010)

Introducción. El objetivo de este estudio ha sido analizar la evolución de la actividad de daptomicina y de otros antimicrobianos frente a Staphylococcus aureus resistente a meticilina (SARM) durante un periodo de 10 años (2001-2010), con el fin de detectar posibles cambios así como la aparición de resistencias. Métodos. Hemos incluido un total de 1.130 aislamientos de SARM procedentes de un estudio multicéntrico de vigilancia de resistencias a los antimicrobianos, estudio VIRA, en el que han participado 51 hospitales españoles a lo largo del periodo 2001- 2010. Los estudios de sensibilidad se han realizado mediante el método de microdilución en caldo según las normas descritas por el Clinical Laboratory Standards Institute. Resultados. Daptomicina ha mostrado excelente actividad frente a todos los aislados, solamente se detectó en el primer año del estudio un aislado no sensible (CMI=2 mg/L). La actividad de daptomicina ha permanecido estable a lo largo de los 10 años. Al analizar los valores de la CMI90, se observó que daptomicina presentaba una actividad de 2 a 4 veces superior a la de vancomicina, teicoplanina y linezolid. Se ha comprobado que daptomicina se mantiene activa frente a aislamientos de SARM resistentes a linezolid, a quinupristina-dalfopristina, o con sensibilidad disminuida a vancomicina. Conclusiones. Teniendo en cuenta la excelente actividad in vitro de la daptomicina observada en este estudio y en diferentes trabajos publicados, así como su potente actividad bactericida, consideramos que este antimicrobiano representa una alternativa en el tratamiento de las infecciones graves por S. aureus multirresistente(AU)

Introduction. The objective of this study was to evaluate the activity of daptomycin and other agents against methicillinresistant Staphylococcus aureus (MRSA) isolates collected from 2001 to 2010, in order to determine changes and to detect resistance trends. Methods. The study included a total of 1,130 MRSA isolates collected as part of a multicenter surveillance program for antibiotic resistance, Estudio de Vigilancia de Resistencia a los Antimicrobianos (VIRA study), from 51 medical centers throughout Spain between 2001 and 2010. Broth microdilution test was performed according to the Clinical Laboratory Standards Institute guidelines. Results. Daptomycin showed excellent activity and maintained its activity over time; only one MRSA isolate collected in 2001 was nonsusceptible to this agent (MIC=2 mg/L). Based on the MIC90, daptomycin was 2-4 dilutions more active than vancomycin, teicoplanin and linezolid. Daptomycin retained activity against MRSA isolates that were resistant to linezolid, to quinupristin-dalfopristin, or showed intermediate susceptibility to vancomycin. Conclusions. Our data and those of other studies, coupled with daptomycin’s rapid bactericidal activity, suggest that this antimicrobial could be an alternative in the treatment of severe infections caused by multiresistant S. aureus(AU)

Comparative in vitro activity of ceftobiprole against Gram-positive cocci.

The activity of ceftobiprole and comparator agents was evaluated against a collection of 880 isolates, comprising 200 meticillin-susceptible Staphylococcus aureus, 200 meticillin-resistant S. aureus, 180 coagulase-negative staphylococci blood isolates, 100 Streptococcuspneumoniae and 200 macrolide-resistant beta-haemolytic streptococci (100 Streptococcus pyogenes and 100 Streptococcus agalactiae). Ceftobiprole showed excellent activity against staphylococci (minimum inhibitory concentrations

Comparative activities of TR-700 (torezolid) against staphylococcal blood isolates collected in Spain.

The in vitro activity of TR-700 (torezolid) was evaluated against a collection of 660 staphylococcal blood isolates. TR-700 showed excellent activity against all the staphylococci tested. The MIC(50) and MIC(90) values of TR-700, linezolid, daptomycin, and vancomycin against methicillin-resistant Staphylococcus aureus (MRSA) isolates were 0.25 and 0.5, 2 and 4, 0.5 and 0.5, and 1 and 2 microg/ml, respectively. TR-700 demonstrated greater in vitro potency than linezolid against staphylococci, including linezolid-resistant and vancomycin-nonsusceptible strains, and was 32-fold more active than linezolid against the seven cfr-positive MRSA strains tested.

Actividad comparativa de la daptomicina frente a Staphylococcus aureus resistente a meticilina y frente a estafilococos coagulasa negativa / Comparative activity of daptomycin against clinical isolates of methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci

El objetivo de este estudio ha sido evaluar la actividad in vitro de la daptomicina frente a una colección de aislamientos de Staphylococcus aureus resistente a meticilina (SARM) de diversas procedencias y frente a estafilococos coagulasa negativa (ECN) procedentes de hemocultivos clínicamente significativos. Métodos Se incluyeron en el estudio un total de 1.186 cepas de estafilococos (755 SARM y 431 ECN) procedentes de 40 hospitales españoles integrados en el programa VIRA (Vigilancia de Resistencias a los Antimicrobianos) correspondientes al período 2001 al 2006. Los estudios de sensibilidad se llevaron a cabo mediante el método de microdilución en caldo. Resultados La mayor parte de los aislamientos de SARM fueron resistentes al ciprofloxacino (96%) y a la eritromicina (79,7%). Los valores de concentración inhibitoria mínima frente al 50 y al 90% de las cepas de daptomicina fueron (..) (AU)

The objective of this study was to determine the in vitro activity of daptomycin and other agents against methicillin-resistant Staphylococcus aureus (MRSA) isolates from several sources and coagulase-negative staphylococci (CoNS) from clinically significant blood cultures. Methods We tested a total of 1186 staphylococci isolates (755 MRSA and 431 CoNS) collected as part of a multicenter surveillance program for antimicrobial resistance (VIRA study) from 40 medical centers throughout Spain between 2001 and 2006. Broth microdilution tests were performed according to the Clinical and Laboratory Standards Institute guidelines. Results Most MRSA isolates were resistant to ciprofloxacin (96%) and erythromycin (79.7%). Daptomycin yielded a (..) (AU)

[Comparative activity of daptomycin against clinical isolates of methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci]. / Actividad comparativa de la daptomicina frente a Staphylococcus aureus resistente a meticilina y frente a estafilococos coagulasa negativa.

INTRODUCTION: The objective of this study was to determine the in vitro activity of daptomycin and other agents against methicillin-resistant Staphylococcus aureus (MRSA) isolates from several sources and coagulase-negative staphylococci (CoNS) from clinically significant blood cultures. METHODS: We tested a total of 1186 staphylococci isolates (755 MRSA and 431 CoNS) collected as part of a multicenter surveillance program for antimicrobial resistance (VIRA study) from 40 medical centers throughout Spain between 2001 and 2006. Broth microdilution tests were performed according to the Clinical and Laboratory Standards Institute guidelines. RESULTS: Most MRSA isolates were resistant to ciprofloxacin (96%) and erythromycin (79.7%). Daptomycin yielded a MIC(50)/MIC(90) of 0.5/1microg/mL in MRSA, compared with 1/2microg/mL for linezolid, vancomycin, and teicoplanin. Daptomycin MICs were in the range of < or =0.125-2microg/mL. Only 1 MRSA strain had a reproducible daptomycin MIC of 2microg/mL. Among CoNS isolates, the MIC range for daptomycin was < or =0.125-1microg/mL. Daptomycin was equally active against oxacillin-susceptible and oxacillin-resistant strains. CONCLUSION: Daptomycin was highly active against the staphylococci isolates studied. The activity of this agent was not affected by resistance to other antibiotics such as oxacillin, teicoplanin, linezolid, ciprofloxacin, or gentamicin. These data suggest that daptomycin may be useful for the treatment of severe infection caused by MRSA or CoNS.

Antimicrobial susceptibility and macrolide resistance genes in Enterococcus faecium with reduced susceptibility to quinupristin-dalfopristin: level of quinupristin-dalfopristin resistance is not dependent on erm(B) attenuator region sequence.

Antimicrobial resistance and the mechanisms implicated were studied in 148 clinical Enterococcus faecium isolates with a quinupristin-dalfopristin (Q/D) MIC > or =1 microg/mL. As expected, higher levels of resistance were detected for macrolide antibiotics (94% erythromycin, 100% azithromycin, 100% josamycin). High-level resistance to gentamicin and streptomycin was detected in 18.9% and 66.2% of isolates, respectively, in our series of enterococci. Resistance against tetracycline was found in only 12.8% of the isolates, and 13 isolates were resistant to vancomycin. The dalvabancin MIC(90) for these isolates was >16 microg/mL. Polymerase chain reaction screening for the previously described streptogramin resistance determinants erm(A), erm(B), mefA/E, vat(D), and vat(E) was performed to determine the prevalence of streptogramin resistance mechanisms in these clinical enterococcal isolates. The combination of erm(B) and vat(D) genes encoding resistance to streptogramins was detected in 1 Q/D-resistant E. faecium isolate. A total of 131 Q/D-nonsusceptible enterococci only contained the erm(B) gene. The erm(B) promoter sequence reveals no differences between the strains analyzed, regardless of the Q/D MIC value.

Activity of daptomycin against staphylococci collected from bloodstream infections in Spanish medical centers.

We used the broth microdilution method to determine the MICs of daptomycin and 13 comparator agents against 319 methicillin-susceptible Staphylococcus aureus isolates, 201 methicillin-resistant S. aureus (MRSA) isolates, and 183 coagulase-negative staphylococci (CoNS). Isolates were consecutively collected from bloodstream infections in 39 Spanish medical centers during a 3-month period (March through May 2008). Among MRSA, 1 isolate with intermediate susceptibility to vancomycin and 6 isolates resistant to linezolid were found. Nonsusceptibility to teicoplanin was detected in 3.9% of CoNS. Daptomycin was highly active against the staphylococcal blood isolates tested-all were inhibited at the daptomycin susceptibility breakpoint of < or = 1 microg/mL. Daptomycin retained its activity against the isolates that were resistant to teicoplanin or linezolid, or that had reduced susceptibility to vancomycin. These data suggest that daptomycin could be useful for the treatment of bloodstream infections caused by staphylococci.

Estudio comparativo de la actividad in vitro de tigeciclina frente a Enterococcus faecium multirresistente / Comparative study of the in vitro activity of tigecycline against multiresistant Enterococcus faecium isolates

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Resistance trends of the Bacteroides fragilis group over a 10-year period, 1997 to 2006, in Madrid, Spain.

The changes in susceptibilities of Bacteroides fragilis group strains isolated in our hospital from 1997 to 2006 were studied. A total of 1,343 clinical strains were included. The study showed differences in the resistance rates in the different species of the group. Increasing resistance to clindamycin and moxifloxacin was observed. Susceptibility to imipenem, piperacillin-tazobactam, and metronidazole remained unchanged.

[Antimicrobial resistance surveillance: VIRA STUDY 2006]. / Vigilancia de resistencias a los antimicrobianos: estudio VIRA 2006.

INTRODUCTION: The objective of this study was to determine the current antimicrobial susceptibility patterns of the most frequent multi-resistant bacteria and to analyze any possible changes with respect to the two VIRA studies carried out in 2001 and 2004. METHODS: In February 2006, the 40 participating hospitals sent the following microorganisms: non-penicillin-susceptible Streptococcus pneumoniae (92), methicillin-resistant Staphylococcus aureus (MRSA) (290), clinically significant coagulase-negative staphylococci (136), ampicillin-resistant Enterococcus faecium (89), ampicillin-resistant Haemophilus influenzae (67), ciprofloxacin-resistant Escherichia coli (365), Pseudomonas aeruginosa (181), and Acinetobacter baumannii (92). The hospitals provided epidemiological data on these microorganisms. Susceptibility was determined with a broth microdilution method. RESULTS: Among the non-penicillin-susceptible S. pneumoniae isolates, the proportion of those ones resistant to this antibiotic showed a significant (p < 0.001) decrease (59.8% in 2001, 30.2% in 2004 and 14.3% in 2006). Among MRSA, we detected one isolate nonsusceptible to linezolid, four resistant to quinupristin-dalfopristin and one strain with a vancomycin MIC of 4 microg/mL. The prevalence of extended-spectrum beta-lactamase-producing E. coli was 12.1%. Resistance of A. baumannii to imipenem varied from 27% in the 2001-2004 period to 47.8% in 2006 (p < 0.005). CONCLUSION: These results again emphasize that resistance surveillance systems are an important tool for preventing the emergence and spread of multi-resistant pathogens.