Evaluation of the usefulness of a quantitative blood culture in the diagnosis of catheter-related bloodstream infection: Comparative analysis of two periods (2002 and 2012) / Evaluación de la utilidad del hemocultivo cuantitativo en el diagnóstico de la bacteriemia relacionada con catéter: análisis comparativo de dos periodos (2002 y 2012)

INTRODUCTION: A retrospective study was conducted to investigate the usefulness of systematic quantitative blood culture (QBC) in the diagnosis of catheter-related bloodstream infection (CRBSI) during two 1-year periods (2002 and 2012). METHODS: The study included all QBC requests sent to the microbiology laboratory for suspected CRBSI in adults (≥18 years) with any type of intravascular catheter (IVC). Based on a ratio of ≥4:1CFU/mL of the same microorganism between IVC blood culture from any lumen and peripheral blood culture, 5 diagnostic groups were defined: confirmed or probable CRBSI, primary BSI, other focus of infection, and colonization. RESULTS: In total, 4521 QBCs were evaluated; 24% positive in 2002 and 16% in 2012 (P<0.0001). There were 243 episodes of suspected CRBSI (101 in 2002 and 142 in 2012). Confirmed CRBSI episodes were higher in 2002 than 2012 (56% vs 34%) (P<0.0001), whereas colonization episodes were lower (18% vs 38%) (P=0.0006). Gram-positive cocci decrease in 2012 relative to 2002 (56% vs 79.7%) (P=0.022). Almost one-third (32%) of confirmed CRBSI would have been missed if blood from all catheter lumens had not been cultured. CONCLUSIONS: QBC is a useful method for diagnosing CRBSI. Blood samples from all catheter lumens must be cultured to avoid missing around one-third of CRBSI diagnoses

INTRODUCCIÓN: Se ha realizado un estudio retrospectivo, para investigar la utilidad del hemocultivo cuantitativo (HC) para el diagnóstico de las bacteriemias relacionadas con catéteres (BRC), durante dos periodos de un año (2002 y 2012). MÉTODOS: Todos los HC recibidos en el laboratorio de microbiología realizados ante la sospecha de BRC, a pacientes ≥18 años portadores de cualquier tipo de catéter intravascular (CIV), han sido incluidos en este estudio. Basándonos en la proporción ≥4:1CFU/mL del mismo microorganismo entre el HC de cualquier luz del CIV y el HC periférico se han definido 5 grupos diagnósticos: BRC confirmada o probable, bacteriemia primaria, otro foco de infección y colonización. RESULTADOS: Han sido evaluados 4521 HC; 24% positivos en 2002 y 16% en 2012 (P<0.0001). Fueron sospechosos de BRC 243 episodios (101 en 2002 y 142 en 2012). El Porcentaje de episodios de BRC confirmados fue mayor en 2002 que en 2012 (56% vs 34%) (P<0.0001), en cambio fue menor el de los episodios de colonización (18% vs 38%) (P=0.0006). Los cocos Gram-positivos disminuyeron en 2012 en relación con 2002 (56% vs 79.7%) (P=0.022). En el 32.2% de las BRC confirmadas se hubiese perdido el diagnóstico si no se hubiera realizado HC de todas las luces. CONCLUSIONES: El HC es un método muy útil para el diagnóstico de las BRC. Hay que obtener muestra de sangre de todas luces para cultivo con el fin de evitar la pérdida de alrededor del 30% de los episodios de BRC

Evaluation of the usefulness of a quantitative blood culture in the diagnosis of catheter-related bloodstream infection: Comparative analysis of two periods (2002 and 2012).

INTRODUCTION: A retrospective study was conducted to investigate the usefulness of systematic quantitative blood culture (QBC) in the diagnosis of catheter-related bloodstream infection (CRBSI) during two 1-year periods (2002 and 2012). METHODS: The study included all QBC requests sent to the microbiology laboratory for suspected CRBSI in adults (≥18 years) with any type of intravascular catheter (IVC). Based on a ratio of ≥4:1CFU/mL of the same microorganism between IVC blood culture from any lumen and peripheral blood culture, 5 diagnostic groups were defined: confirmed or probable CRBSI, primary BSI, other focus of infection, and colonization. RESULTS: In total, 4521 QBCs were evaluated; 24% positive in 2002 and 16% in 2012 (P<0.0001). There were 243 episodes of suspected CRBSI (101 in 2002 and 142 in 2012). Confirmed CRBSI episodes were higher in 2002 than 2012 (56% vs 34%) (P<0.0001), whereas colonization episodes were lower (18% vs 38%) (P=0.0006). Gram-positive cocci decrease in 2012 relative to 2002 (56% vs 79.7%) (P=0.022). Almost one-third (32%) of confirmed CRBSI would have been missed if blood from all catheter lumens had not been cultured. CONCLUSIONS: QBC is a useful method for diagnosing CRBSI. Blood samples from all catheter lumens must be cultured to avoid missing around one-third of CRBSI diagnoses.

Clinical and microbiological profile of a retrospective cohort of enteric fever in 2 Spanish tertiary hospitals.

Enteric fever in high-income countries is diagnosed mainly in patients returning from endemic countries. We assess the clinical, microbiological, and prognosis aspects of enteric fever in 2 Spanish tertiary hospitals. A retrospective observational study was conducted at Vall d'Hebron University Hospital and Ramón y Cajal University Hospital in Spain. We reviewed medical records of all patients who were diagnosed with enteric fever from January 2000 to January 2014 at these hospitals. We identified 47 patients with enteric fever episodes. According to their travel history, 35 (74.5%) patients had travelled to highly endemic countries. Imported enteric fever was acquired mainly in Asia (70.3%). Imported infections were implicated in travelers (48.6%), visiting friends and relatives (40%) and immigrants (11.4%). We found that 12 patients were diagnosed with enteric fever without a travel history (autochthonous infection). The resistance profile of the isolates showed decreased ciprofloxacin susceptibility in 66.7% of the imported group and 8.3% of the autochthonous group (P = 0.001). Salmonella strains from patients returning from Asia had an increased risk of having decreased ciprofloxacin susceptibility (odds ratio, 52.25; 95% confidence interval: 8.6-317.7). Patients with imported enteric fever are at higher risk for having a Salmonella strain with decreased ciprofloxacin susceptibility, especially in patients returning from Asia. Initial treatment with third-generation cephalosporin or azithromycin is strongly recommended until a drug-susceptibility test is available. Prevention strategies such as pretravel counseling and immunization before travel may be beneficial.

ESBL-producing Salmonella enterica serovar Typhi in traveler returning from Guatemala to Spain.

We report a case of typhoid fever in a traveler returning to Spain from Guatemala that was caused by Salmonella enterica serovar Typhi which produced an extended-spectrum ß-lactamase (ESBL). This finding demonstrates the presence of ESBL-producing S. enterica ser. Typhi strains in the Americas. Enhanced surveillance is necessary to prevent further spread.

Effects of immunocompromise and comorbidities on pneumococcal serotypes causing invasive respiratory infection in adults: implications for vaccine strategies.

BACKGROUND: The 13-valent pneumococcal conjugate vaccine (PCV13) has recently been approved for use in immunocompromised adults. However, it is unclear whether there is an association between specific underlying conditions and infection by individual serotypes. The objective was to determine the prevalence of serotypes covered by PCV13 in a cohort of patients with invasive pneumococcal disease of respiratory origin and to determine whether there are specific risk factors for each serotype. METHODS: An observational study of adults hospitalized with invasive pneumococcal disease in 2 Spanish hospitals was conducted during the period 1996-2011. A multinomial regression analysis was performed to identify conditions associated with infection by specific serotypes (grouped according their formulation in vaccines and individually). RESULTS: A total of 1094 patients were enrolled; the infecting serotype was determined in 993. In immunocompromised patients, 64% of infecting serotypes were covered by PCV13. After adjusting for age, smoking, alcohol abuse, and nonimmunocompromising comorbidities, the group of serotypes not included in either PCV13 or PPV23 were more frequently isolated in patients with immunocompromising conditions and cardiopulmonary comorbidities. Regarding individual serotypes, 6A, 23F, 11A, and 33F were isolated more frequently in patients with immunocompromise and specifically in some of their subgroups. The subgroup analysis showed that serotype10A was also associated with HIV infection. CONCLUSIONS: Specific factors related to immunocompromise seem to determine the appearance of invasive infection by specific pneumococcal serotypes. Although the coverage of serotypes in the 13-valent conjugate pneumococcal vaccine (PCV13) was high, some non-PCV13-emergent serotypes are more prevalent in immunocompromised patients.

Effectiveness of antibiotic-lock therapy for long-term catheter-related bacteremia due to Gram-negative bacilli: a prospective observational study.

A prospective observational study evaluated the effectiveness of combining antibiotic-lock therapy and systemic antibiotics for Gram-negative bacilli long-term catheter-related bacteremia. In 46 uncomplicated episodes, the most frequently isolated microorganisms were Pseudomonas aeruginosa (15), Enterobacter cloacae (12), Escherichia coli (10), and Klebsiella spp. (8). Cure was achieved in 95% of cases.

Molecular characterization of clinical Saccharomyces cerevisiae isolates and their association with non-clinical strains.

We assessed the molecular characterization of 96 clinical isolates of S. cerevisiae from a Spanish medical institution and we compared them with 6 non-clinical strains isolated from wine, beer and bread and 1 S. boulardii strain collected from a commercial preparation. The strains were subjected to HinfI mtDNA restriction analysis and PCR amplification of delta sequences. Although both techniques are appropriate for routine clinical analysis, that based on PCR turned out to be the most discriminating. This study, apart from providing tools for clinical application, deals with the relationships between clinical and non-clinical strains. The two baker's yeasts analysed shared mtDNA and PCR patterns with a group of 31 clinical isolates. An exogenous entry of a strain was also reflected in the case of 19 clinical isolates and the therapeutic strain S. boulardii. Both baker's yeasts and S. boulardii were identified respectively among 32.3% and 19.8% of the clinical isolates and there seemed to be a connection between their ability to colonize humans and their ability to cause vaginal infection. The rest of food isolates were not grouped with clinical strains.

Evolución de la sepsis perinatal por Escherichia coli en la era de la profilaxis del estreptococo del grupo B / Evolution of perinatal Escherichia coli disease in the era of group B Streptococcus prophylaxis

FUNDAMENTO: Caracterizar la sepsis perinatal precoz por Escherichia coli y analizar su posible correlación con la implantación de la profilaxis del estreptococo del grupo B (EGB). PACIENTES Y MÉTODO: Entre 1994 y 2000, 24 neonatos nacidos en nuestro centro fueron diagnosticados de sepsis perinatal por E. coli; 12 procedían de madres cuyo embarazo fue controlado en nuestro centro y 12 de madres remitidas poco antes del parto. Además se diagnosticaron otras tres sepsis perinatales por E. coli en niños remitidos con posterioridad a su nacimiento. RESULTADOS: La incidencia anual no cambió significativamente (riesgo relativo [RR] 1,065; intervalo de confianza [IC] del 95 por ciento, -0,873 a 1,301; p = 0,533), oscilando del 0,6 en 1994 al 1,7 en 1997 y al 0,5 en 2000. El 92 por ciento de las madres presentaron factores de riesgo obstétrico: el 68 por ciento parto prematuro (media: 32,9 semanas; mediana: 32), el 64 por ciento rotura prolongada de membrana (media: 184 h; mediana: 44), y el 56 por ciento fiebre intraparto. El 12 por ciento de las gestantes recibieron ampicilina intraparto como profilaxis de la sepsis por EGB y el 80 por ciento antibioterapia: 6 como profilaxis de la rotura de membranas, 6 como tratamiento de su infección urinaria y 8 como tratamiento de una posible corioamnionitis. El 81 por ciento de E. coli aislados en los neonatos fueron resistentes a la ampicilina. No se ha encontrado relación entre E. coli resistente a ampicilina y prematuridad (p = 0,57), rotura de membranas (p = 0,63), fiebre intraparto (p = 0,24) o fallecimiento (p = 0,53). CONCLUSIONES: Estos resultados sugieren que la sepsis perinatal por E. coli no está relacionada con la aplicación de medidas profilácticas contra EGB, sino con la prematuridad, la prolongación del embarazo en la rotura prematura de membranas y exposición a la antibioterapia que todo ello comporta (AU)