Microbiological diagnosis of catheter-related infections / Diagnóstico microbiológico de las infecciones asociadas a catéteres intravasculares

This revision describes in detail the different diagnostic techniques of catheter-related infection, both in terms of catheter removal and preservation. Culture techniques based on catheter withdrawal are classified depending on the detection of extraluminal and/or intraluminal colonization, and new methodologies are described. In general, the most important recommendations are: (a) do not send for culture catheter tips without suspicion of infection, (b) Maki's technique is the standard for detecting extraluminal colonization, (c) take 2 pairs of peripheral blood cultures before starting antibiotic treatment, (d) use skin and connections/connectors cultures for the conservative diagnosis due to their high negative predictive value (Gram and culture), and (e) take differential quantitative blood cultures though all catheter lumens and through a peripheral vein

Esta revisión describe con detalle las diferentes técnicas diagnósticas de infección relacionada con el catéter, tanto con la retirada como con la conservación del mismo. Las técnicas de cultivo basadas en la retirada del catéter se clasifican en base a la detección de colonización extraluminal, intraluminal, o ambas, asimismo, se describen nuevas metodologías. De forma general, las recomendaciones más importantes son: a) no enviar para cultivo puntas de catéter retiradas sin sospecha de infección, b) la técnica de Maki es el estándar válido de detección de colonización extraluminal, c) tomar 2 parejas de hemocultivos de sangre periférica antes de iniciar tratamiento antibiótico, d) utilizar cultivos de piel y conexiones/conectores para el diagnóstico conservador por su alto valor predictivo negativo (Gram y cultivo), y e) extraer hemocultivos cuantitativos diferenciales por todas las luces del catéter y por vena periférica

Microbiological diagnosis of catheter-related infections.

This revision describes in detail the different diagnostic techniques of catheter-related infection, both in terms of catheter removal and preservation. Culture techniques based on catheter withdrawal are classified depending on the detection of extraluminal and/or intraluminal colonization, and new methodologies are described. In general, the most important recommendations are: (a) do not send for culture catheter tips without suspicion of infection, (b) Maki's technique is the standard for detecting extraluminal colonization, (c) take 2 pairs of peripheral blood cultures before starting antibiotic treatment, (d) use skin and connections/connectors cultures for the conservative diagnosis due to their high negative predictive value (Gram and culture), and (e) take differential quantitative blood cultures though all catheter lumens and through a peripheral vein.

Meningitis por Streptococcus suis: ¿una zoonosis emergente? / Streptococcus suis meningitis: an emergent zoonosis?

Streptococcus suis es un importante patógeno asociado con una amplia gama de enfermedades en cerdos, y constituye uno de los problemas más importantes de la industria porcina en todo el mundo. Sin embargo, la infección por S.suis en humanos es poco frecuente y se considera una zoonosis inusual, ya que desde 1968 hasta 2004 solo se habían descrito alrededor de 250 casos en todo el mundo. La aparición de algunos brotes muy extensos de infección por S.suis en Europa y Sudeste Asiático a partir del año 2005, y el aumento de la incidencia de casos en otros países europeos, ha hecho pensar que podemos encontrarnos ante un proceso de emergencia de estas infecciones. S. suis es un coco grampositivo anaerobio facultativo perteneciente a los grupos R, S y T de Lancefield. Hasta hace poco ha habido importantes dificultades en la identificación y diferenciación de este microorganismo de otras especies de Streptococcus, lo que podría ser la causa de una infravaloración de estas infecciones. Actualmente se cuenta con herramientas de diagnóstico y tipificación molecular que permiten una mejor caracterización de los aislados. La infección más frecuente por S.suis en humanos es la meningitis, pero se han descrito casos de endocarditis, neumonía, celulitis, abdomiólisis, artritis, espondilodiscitis, absceso epidural, peritonitis, enteritis, endoftalmitis, uveítis, síndrome de shock tóxico estreptocócico, septicemia con shock séptico y fallo multiorgánico. En nuestro país se han documentado menos de una veintena de casos de infección por S.suis, por lo que creemos de interés comunicar un nuevo caso de meningitis por S.suis

Streptococcus suis is an important pathogen associated with a wide range of diseases in pigs, constituting one of the most important problems of the swine industry around the world. However, infection with S.suis in humans is very rare and is considered an unusual zoonosis because from 1968 until 2004 had described only around 250 cases around the world. The emergence of some very large outbreaks of infection with S.suis in Europe and Southeast Asia from the year 2005, and the increase in the incidence of cases in other European countries, has made to think that we can find about a process of emergence of these infections. S.suis is a Gram-positive facultative anaerobic coccus, belonging to R, S, and T Lancefield groups. Until recently, there have been major difficulties in the identification and differentiation of this organism of other Streptococcus species, what could be the cause of an underestimation of these infections. It's currently with diagnostic tools and molecular typing that allow a better characterization of the isolates. The most frequent S.suis in humans infection is meningitis, but endocarditis, pneumonia, cellulitis, rhabdomyolysis, arthritis, spondylodiscitis, abscess epidural, peritonitis, enteritis, endophthalmitis, uveitis, septicemia with septic shock and multiorgan failure streptococcal toxic shock syndrome have also been reported. In our country less than 20 cases of S.suis infection have been documented, so we believe interest communicate a new case of S.suis meningitis

Quality of the aetiological diagnosis of ventilator-associated pneumonia in Spain in the opinion of intensive care specialists and microbiologists / Calidad del diagnóstico etiológico de la neumonía asociada a ventilación mecánica en España según la opinión de intensivistas y microbiólogos

INTRODUCTION: Current guidelines for the microbiological diagnosis of ventilator-associated pneumonia (VAP) are imprecise. Based on data provided by intensive care specialists (ICS) and microbiologists, this study defines the clinical practices and microbiological techniques currently used for an aetiological diagnosis of VAP and pinpoints deficiencies. METHODS: Eighty hospitals in the national health network with intensive care and microbiology departments were sent two questionnaires, one for each department, in order to collect data on VAP diagnosis for the previous year. RESULTS: Out of the 80 hospitals, 35 (43.8%) hospitals participated. These included 673 ICU beds, 32,020 ICU admissions, 173,820 ICU days stay, and generated 27,048 lower respiratory tract specimens in the year. A third of the hospitals (35%) had a microbiology department available 24/7. Most samples (83%) were tracheal aspirates. Gram stain results were immediately reported in around half (47%) of the hospitals. Quantification was made in 75% of hospitals. Molecular techniques and direct susceptibility testing were performed in 12% and one institution, respectively. Mean turnaround time for a microbiological report was 1.7 (SD; 0.7), and 2.2 (SD; 0.6) days for a negative and positive result, respectively. Telephone/in-person information was offered by 65% of the hospitals. Most (89%) ICS considered microbiological information as very useful. No written procedures were available in half the ICUs. CONCLUSIONS: Both ICS and microbiologists agreed that present guidelines for the diagnosis of VAP could be much improved, and that a new set of consensus guidelines is urgently required. A need for guidelines to be more effectively implemented was also identified in order to improve outcomes in patients with VAP

INTRODUCCIÓN: Las guías para el diagnóstico microbiológico de la neumonía asociada a la ventilación mecánica (NAVM) son imprecisas. Este estudio describe la práctica clínica y las técnicas microbiológicas según la información proporcionada por intensivistas y microbiólogos de varias UCIs españolas, e identifica deficiencias y oportunidades de mejora. MÉTODOS: Se enviaron cuestionarios a 80 hospitales públicos españoles con servicios de cuidados intensivos y de microbiología, solicitando datos sobre el diagnóstico de la NAVM en el año anterior. RESULTADOS: Los 35 hospitales participantes (43,8%) abarcaron 673 camas de UCI con 32.020 admisiones y 173,820 estancias, y generaron 27.048 muestras del tracto respiratorio inferior. El 35% disponía de un servicio de microbiología 24/7. El 83% de las muestras fueron aspirados endotraqueales; el 47% de los Gram se informaron de inmediato y el 75% de las muestras se procesaron de manera semicuantitativa. Las técnicas moleculares y el antibiograma directo se realizaron en el 12% de los casos y en una institución, respectivamente. La respuesta media fue de 1,7 (DE 0,7) y 2,2 (SD 0,6) días para un cultivo negativo y uno positivo, respectivamente. La información directa estuvo disponible en el 65% de los hospitales. El 89% de los intensivistas consideraron muy útil la información microbiológica. En la mitad de la UCIs no había protocolos escritos de manejo de esta entidad. CONCLUSIONES: Intensivistas y microbiólogos coinciden en que las guías actuales para el diagnóstico de NAVM se podrían mejorar significativamente. También es necesario implementar las guías de manera más efectiva para mejorar la evolución de los pacientes

Quality of the aetiological diagnosis of ventilator-associated pneumonia in Spain in the opinion of intensive care specialists and microbiologists.

INTRODUCTION: Current guidelines for the microbiological diagnosis of ventilator-associated pneumonia (VAP) are imprecise. Based on data provided by intensive care specialists (ICS) and microbiologists, this study defines the clinical practices and microbiological techniques currently used for an aetiological diagnosis of VAP and pinpoints deficiencies. METHODS: Eighty hospitals in the national health network with intensive care and microbiology departments were sent two questionnaires, one for each department, in order to collect data on VAP diagnosis for the previous year. RESULTS: Out of the 80 hospitals, 35 (43.8%) hospitals participated. These included 673 ICU beds, 32,020 ICU admissions, 173,820 ICU days stay, and generated 27,048 lower respiratory tract specimens in the year. A third of the hospitals (35%) had a microbiology department available 24/7. Most samples (83%) were tracheal aspirates. Gram stain results were immediately reported in around half (47%) of the hospitals. Quantification was made in 75% of hospitals. Molecular techniques and direct susceptibility testing were performed in 12% and one institution, respectively. Mean turnaround time for a microbiological report was 1.7 (SD; 0.7), and 2.2 (SD; 0.6) days for a negative and positive result, respectively. Telephone/in-person information was offered by 65% of the hospitals. Most (89%) ICS considered microbiological information as very useful. No written procedures were available in half the ICUs. CONCLUSIONS: Both ICS and microbiologists agreed that present guidelines for the diagnosis of VAP could be much improved, and that a new set of consensus guidelines is urgently required. A need for guidelines to be more effectively implemented was also identified in order to improve outcomes in patients with VAP.

Comparison of three statistical methods for establishing tentative wild-type population and epidemiological cutoff values for echinocandins, amphotericin B, flucytosine, and six Candida species as determined by the colorimetric Sensititre YeastOne method.

The Sensititre YeastOne (SYO) method is a widely used method to determine the susceptibility of Candida spp. to antifungal agents. CLSI clinical breakpoints (CBP) have been reported for antifungals, but not using this method. In the absence of CBP, epidemiological cutoff values (ECVs) are useful to separate wild-type (WT) isolates (those without mechanisms of resistance) from non-WT isolates (those that can harbor some resistance mechanisms), which is the goal of any susceptibility test. The ECVs for five agents, obtained using the MIC distributions determined by the SYO test, were calculated and contrasted with those for three statistical methods and the MIC(50) and modal MIC, both plus 2-fold dilutions. The median ECVs (in mg/liter) (% of isolates inhibited by MICs equal to or less than the ECV; number of isolates tested) of the five methods for anidulafungin, micafungin, caspofungin, amphotericin B, and flucytosine, respectively, were as follows: 0.25 (98.5%; 656), 0.06 (95.1%; 659), 0.25 (98.7%; 747), 2 (100%; 923), and 1 (98.5%; 915) for Candida albicans; 8 (100%; 352), 4 (99.2%; 392), 2 (99.2%; 480), 1 (99.8%; 603), and 0.5 (97.9%; 635) for C. parapsilosis; 1 (99.2%; 123), 0.12 (99.2%; 121), 0.25 (99.2%; 138), 2 (100%; 171), and 0.5 (97.2%; 175) for C. tropicalis; 0.12 (96.6%; 174), 0.06 (96%; 176), 0.25 (98.4%; 188), 2 (100%; 209), and 0.25 (97.6%; 208) for C. glabrata; 0.25 (97%; 33), 0.5 (93.9%; 33), 1 (91.9%; 37), 4 (100%; 51), and 32 (100%; 53) for C. krusei; and 4 (100%; 33), 2 (100%; 33), 2 (100%; 54), 1 (100%; 90), and 0.25 (93.4%; 91) for C. orthopsilosis. The three statistical methods gave similar ECVs (within one dilution) and included ≥ 95% of isolates. These tentative ECVs would be useful for monitoring the emergence of isolates with reduced susceptibility by use of the SYO method.

Variación de la epidemiología de las fungemias y de la sensibilidad al fluconazol de los aislamientos de hemocultivos en los últimos 10 años en España: resultados del estudio FUNGEMYCA / Changes in the epidemiology of fungaemia and fluconazole susceptibility of blood isolates during the last 10 years in Spain: results from the FUNGEMYCA study

Antecedentes. Recientemente se ha observado un incremento de las fungemias causadas por especies diferentes de Candida albicans y una disminución de la sensibilidad de los microorganismos responsables al fluconazol. Objetivos. Evaluar la epidemiología y la sensibilidad al fluconazol de los casos de fungemia en España en 2009, comparando los resultados con los obtenidos entre los años 1997-1999 (Pemán J, et al. Eur J Clin Microbiol Infect Dis. 2005). Métodos. Estudio prospectivo multicéntrico con 44 centros participantes realizado desde enero de 2009 a febrero de 2010. Los aislamientos fúngicos procedentes de hemocultivo fueron recogidos en cada centro, donde se realizó el estudio de sensibilidad antifúngica mediante microdilución colorimétrica (Sensititre Yeast One). Resultados. Desde enero de 2009 a febrero de 2010 se recogieron 1.377 aislamientos en hemocultivos, correspondientes a 1.357 episodios de fungemia. Las fungemias se observaron principalmente en mayores de 64 años (46,7%) y el 8,6% en menores de 1 año. C. albicans (44,7%), Candida parapsilosis (29,1%), Candida glabrata (11,5%), Candida tropicalis (8,2%) y Candida krusei (1,9%) fueron las especies más frecuentes, pero su distribución no fue geográficamente homogénea. En los últimos 10 años la incidencia de C. albicans ha aumentado significativamente en Cataluña (39,1 vs. 54,7%, P=0,03) y reducido en la Comunidad Valenciana (49,1 vs. 34,6%, P=0,01). C. parapsilosis ha disminuido en Cataluña (29 vs. 12,4%, P=0,002) y Extremadura (58,3 vs. 20%, P=0,01). La sensibilidad a fluconazol fue similar en toda España pero en los aislamientos de C. albicans la resistencia fue diez veces superior en mayores de 64 años. Sin embargo, la tasa de resistencia (CMI > 32 mg/L) global ha disminuido con respecto a la obtenida hace 10 años (3,7 vs. 2,5% actual), sobre todo en C. albicans (3 vs. 1,6%). Conclusiones. En los últimos 10 años la distribución de las especies causantes de fungemia en España y la sensibilidad al fluconazol no han variado significativamente, aunque se observa una menor tasa de resistencia. La distribución de las especies varía según la unidad de hospitalización, hospital y Comunidad Autónoma(AU)

Background. Recent epidemiological surveillance studies have reported an increase in fungaemia caused by non-Candida albicans species, as well as a decrease in fluconazole susceptibility. Objectives. To evaluate changes in the epidemiology of fungaemia in Spain comparing data from a new surveillance epidemiological study conducted in 2009 with a previous study carried out from 1997 to 1999 (Pemán J, et al. Eur J Clin Microbiol Infect Dis. 2005). Methods. From January 2009 to February 2010, 44 Spanish hospitals participated in a prospective multicentre fungaemia surveillance study to ascertain whether there have been changes in the epidemiology and fluconazole susceptibility. Susceptibility was determined by the colorimetric method Sensititre Yeast One. Demographic and clinical data and the first isolate of each episode were gathered. Results. A total of 1,377 isolates from 1,357 fungaemia episodes were collected, 46.7% from patients older than 64years and 8.6% from children less than 1 year old. C. albicans (44.7%), Candida parapsilosis (29.1%), Candida glabrata (11.5%), Candida tropicalis (8.2%), and Candida krusei (1.9%) were the most frequent species isolated. Distribution varied with the geographical area. C. albicans incidence has increased significantly in the last 10years in Cataluña (39.1 vs. 54.7%, P =0.03) and decreased in the Valencian Community (49.1 vs. 34.6%, P =0.002) and Extremadura (58.3 vs. 20%, P =0.01). Susceptibility to fluconazole was similar for all geographical areas, although resistance in C. albicans was ten times greater for patients aged more than 64years. The overall rate of fluconazole resistance (MIC > 32 mg/L) has decreased with respect to that obtained 10years ago (3.7 vs. 2.5%) mainly in C. albicans (3 vs. 1.6%). Conclusions. In the last ten years, species distribution and fluconazole susceptibility have not significantly changed, although a lower rate of fluconazole resistance has been observed. Species distribution varies with hospital, hospitalization Unit and geographical area(AU)

Myocarditis caused by human parainfluenza virus in an immunocompetent child initially associated with 2009 influenza A (H1N1) virus.

The association between respiratory viruses and myocarditis has hardly ever been described. We report a case of acute myocarditis in an immunocompetent child associated with the presence of parainfluenza virus type 3 infection, in a context of recent influenza illness, confirmed by molecular and serological studies.

Does treatment of hepatitis B virus (HBV) infection reduce hepatitis delta virus (HDV) replication in HIV-HBV-HDV-coinfected patients?

BACKGROUND: Hepatitis delta virus (HDV) has a unique replication process that requires coinfection with hepatitis B virus (HBV). Treatment is currently limited to interferon therapy. The role of potent nucleos(t)ide analogues active against HBV has not been well examined in chronic delta hepatitis (CDH). METHODS: HIV-positive patients with CDH attending our hospital were identified and longitudinally studied. Serum HBV DNA, HDV RNA and HIV RNA, treatment regimens, and biochemical and serological markers were assessed at yearly intervals. Liver fibrosis was measured by transient elastography during the last 2 years. RESULTS: Sixteen patients were identified and treated with anti-HBV therapy (median time 6.1 years). The majority were male and previous intravenous drug users. Median baselines were: HDV RNA 7 log10 copies/ml, HIV RNA 1.7 log10 copies/ml, HBV DNA 1.1 log10 IU/ml and alanine aminotransferase (ALT) 98 IU/ml. A significant correlation was found between HDV RNA and HBV DNA (r=0.226, P=0.015), aspartate aminotransferase (r=0.430, P<0.0001), ALT (r=0.441, P<0.0001) and hepatitis B surface antigen (HBsAg) (r=0.557, P<0.0001). Overall, 13 patients showed a reduction in HDV viraemia and ALT levels, and three of them achieved undetectable HDV RNA and normal ALT levels. CONCLUSION: Patients undergoing successful anti-HBV therapy with potent nucleos(t)ide analogues seem to indirectly benefit from suppression of HDV replication, albeit not very efficiently. Hypothetically, a significant and sustained reduction in serum HDV RNA might only be seen when a reduction in HBV covalently closed circular DNA or HBV surface antigen is achieved, which may require long periods of successful anti-HBV therapy. To our knowledge, this is the first evidence of the benefit of potent anti-HBV nucleos(t)ide analogue therapy in CDH.

Impact of zygomycosis on microbiology workload: a survey study in Spain.

This multicenter, population-based study evaluated the laboratory workload produced by zygomycetes and the number of cases of zygomycosis in Spain during 2005. Less than 8% of the patients who harbored zygomycete isolates had zygomycosis. The incidence of zygomycosis (6 cases) was 0.43 cases/1,000,000 inhabitants and 0.62 cases/100,000 hospital admissions.

In vitro activities of amphotericin B, caspofungin, itraconazole, posaconazole, and voriconazole against 45 clinical isolates of zygomycetes: comparison of CLSI M38-A, Sensititre YeastOne, and the Etest.

We evaluated the activities of amphotericin B, itraconazole, voriconazole, caspofungin, and posaconazole against zygomycetes by CLSI M38-A, Etest and Sensititre. The most active drug was posaconazole, followed by amphotericin B and itraconazole. The correlation of the Etest and Sensititre with CLSI M38-A was moderate for posaconazole but poor for the others.

In vitro activities of tigecycline and eight other antimicrobials against different Nocardia species identified by molecular methods.

The in vitro activities of tigecycline and other antimicrobials against 51 isolates of Nocardia spp. were evaluated. MIC(90)s and MIC ranges were as follows: tigecycline, 4 and < or =0.06 to 8 mg/liter, respectively; minocycline, 2 and < or =0.06 to 2 mg/liter, respectively; linezolid, 1 and < or =0.06 to 2 mg/liter, respectively; moxifloxacin, 2 and < or =0.06 to >64 mg/liter, respectively; ertapenem, 32 and < or =0.06->64 mg/liter, respectively; imipenem, 2 and < or =0.06 to >64 mg/liter, respectively; meropenem, 8 and < or =0.06 to >64 mg/liter, respectively; amikacin, 1 and < or =0.06 to 32 mg/liter, respectively; and trimethoprim-sulfamethoxazole, 1/19 and < or =0.5/9.5 to >2/38 mg/liter, respectively.