Amadeu Gene

Serotype-Specific Changes in Invasive Pneumococcal Disease after Pneumococcal Conjugate Vaccine Introduction: A Pooled Analysis of Multiple Surveillance Sites

In a pooled analysis of data collected from invasive pneumococcal disease surveillance databases, Daniel Feikin and colleagues examine serotype replacement after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7) into national immunization programs. Please see later in the article for the Editors Summary

Candidemia in neonatal intensive care units: Barcelona, Spain.

Background: Candida spp. are increasingly important hospital-acquired pathogens in neonatal intensive care units (NICU) and cause considerable mortality in preterm infants. Most studies have been limited to a single institution. The aim of this study was to determine the epidemiology of candidemia in all Barcelona NICUs. Methods: We conducted prospective population-based surveillance for candidemia in Barcelona, Spain, during 2002–2003. This report focuses on the results from 5 participating hospitals with NICUs. Results: We detected 24 cases, resulting in an annual incidence of 32.6 cases per 100,000 live births and 1.1 cases per 100 NICU discharges. Median gestational age was 27.5 weeks (range, 24–40.5), and there were 21 cases among very low birth weight infants. Among the 20 (83%) cases evaluated for the presence of end organ infection, endophthalmitis occurred in 2 cases, and endocarditis, meningitis and peritonitis occurred in 1 case each. Candida parapsilosis was the most frequent species isolated (67%). All isolates were fluconazole-susceptible. Crude mortality was 21%. Conclusions: The preponderance of C. parapsilosis candidemias observed in Barcelona NICUs is similar to reports from the literature. Morbidity and mortality associated with neonatal candidemia remain high.

Emergence of invasive pneumococcal disease caused by multidrug-resistant serotype 19A among children in Barcelona☆

OBJECTIVEnTo describe the epidemiology of invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae serotype 19A.nnnMETHODSnWe studied all children and adolescents with IPD caused by serotype 19A who were admitted to a Childrens Hospital in Barcelona (1997-2007). Serotyping, antibiotic susceptibility and clonal analysis were performed.nnnRESULTSnComparing the pre-vaccine period (1997-2001) with the early vaccine period (2002-2004) and the late vaccine period (2005-2007) there was an increase of IPD caused by serotype 19A: 1 of 58 episodes (1.7%) vs. 8 of 54 episodes (14.8%) vs. 27 of 123 episodes (21.9%), respectively (P = 0.002). All S. pneumoniae serotype 19A isolated in the pre-vaccine and early vaccine periods (n = 9) were penicillin susceptible, while in the late vaccine period, 12 of 27 (44%) were penicillin nonsusceptible (P = 0.01). A clonal analysis revealed 15 different sequence types (STs) expressing serotype 19A. 10 of them were preexisting STs associated with serotype 19A including the multidrug-resistant ST320 and ST276.nnnCONCLUSIONnThere was an increase of IPD caused by S. pneumoniae serotype 19A which was mainly related with the emergence of preexisting clones several of them closely related with international multidrug-resistant clones. These results should be considered when selecting the new conjugate pneumococcal vaccines.

Enhanced culture detection of Kingella kingae, a pathogen of increasing clinical importance in pediatrics.

Osteoarticular infection and occult bacteremia are the 2 invasive infectious pathologies most frequently associated in childhood with Kingella kingae. We report a series of 11 patients in whom osteomyelitis predominates over septic arthritis, which is the reverse of other series, probably as a consequence of inoculation of samples during surgery on agar media, used in combination with or as an alternative to inoculation into blood culture bottles. Although K. kingae infections usually follow a benign clinical course, we noted 2 patients with mild orthopedic sequelae.

Pediatric parapneumonic pleural effusion: epidemiology, clinical characteristics, and microbiological diagnosis.

In recent years an increase in the incidence and severity of parapneumonic pleural effusion (PPE) in pediatric populations has been observed. Streptococcus pneumoniae remains the main causal agent. New molecular and antigen techniques have increased the microbiological diagnosis of this pathology.

Etiología de la otitis media aguda en un hospital pediátrico y sensibilidad a los antibióticos de los microorganismos implicados

Fundamento El objetivo de este estudio es conocer de forma actualizada la etiologia bacteriana de la otitis media aguda (OMA) y la sensibilidad antibiotica de los microorganismos implicados, asi como determinar la prevalencia de los serotipos circulantes de Streptococcus pneumoniae. Metodos Se han estudiado retrospectivamente 240 muestras de secrecion otica obtenidas por aspiracion mediante timpanocentesis diagnostica y 167 muestras obtenidas mediante frotis de secrecion espontanea, procesadas entre los anos 1999 y 2001. Resultados La edad media del total de pacientes incluidos en el estudio fue de 17 meses y la mediana de 13 meses (rango, 1 mes-7 anos). De las muestras obtenidas por timpanocentesis en 67 (27,9%) se aislo S. pneumoniae; en 60 (25%), Haemophilus influenzae; en 3 (1,3%), S. pneumoniae y H. influenzae, y en 6 (2,5%), Moraxella catarrhalis. En las muestras obtenidas por frotis de secrecion otica espontanea en 15 (9%) se aislo S. pneumoniae, en 25 (15%) H. influenzae y en 1 (0,6%) S. pneumoniae y H. influenzae. El resto de muestras fueron negativas o se aislaron microorganismos colonizadores. El 49,3% de las cepas de S. pneumoniae tenian sensibilidad intermedia (concentracion inhibitoria minima [CIM]: 0,12-1 μg/ml) y 16,9% fueron resistentes (CIM: >= 2 μg/ml) frente a penicilina y el 54% de las cepas fueron resistentes a macrolidos. El 24,7% de las cepas de H. influenzae aisladas eran productoras de betalactamasas y, por tanto, resistentes a ampicilina, asi como todas las cepas de M. catarrhalis. De las 76 cepas de S. pneumoniae en que se dispone del serotipo, 64 (84,2%) pertenecen a los serotipos incluidos en la vacuna neumococica heptavalente. Conclusiones S. pneumoniae y H. influenzae destacan como los principales agentes etiologicos de la OMA con una sensibilidad antibiotica que sigue el patron general de resistencias de nuestro pais. El cultivo de secrecion otica espontanea tiene escasa utilidad para establecer la etiologia de la OMA. El conocimiento de la actual distribucion de serotipos de S. pneumoniae es la referencia para valorar los posibles cambios epidemiologicos debidos a la introduccion de la vacuna neumococica heptavalente.

Polymerase chain reaction for diagnosis and serogrouping of meningococcal disease in children.

A prospective study was performed including all children younger than 18 years with the clinical diagnosis of invasive meningococcal disease (IMD) hospitalized at the University Hospital Sant Joan de Déu in Barcelona, Spain, from January 2001 to December 2006. During the study period, 168 meningococcal disease cases were reported. Microbiologic confirmation was obtained in 118 cases. Forty-six (38.9%) of 118 cases were only detected by polymerase chain reaction (PCR); 6 patients were culture positive and PCR negative (5%). Serogroup B predominated in the 6-year period with 83.1% of the strains. A significant decrease in serogroup C was observed in the last 3 years of the study (P=0.029), and less common serogroups, such as serogroup A and W135, emerged. Serogroup distribution of patient diagnoses only by real-time PCR showed a similar distribution: serogroup B, 85.7%; serogroup C, 7.1%; and nontypeable serogroups, 7.1%. In conclusion, real-time PCR is more rapid and sensitive than culture for diagnosis and serogrouping of IMD.

Infecciones por Helicobacter pylori: detección de antígeno en muestras fecales

Fundamento El objetivo del estudio es evaluar la tecnica de deteccion del antigeno de Helicobacter pylori en heces (HpSA), y comparar los resultados con los de las tecnicas standard (prueba del aliento con 13C-urea, serologia, cultivo y estudio histologico), en una poblacion de pacientes pediatricos con sintomatologia gastrointestinal sugestiva de infeccion por H.pylori. Pacientes y metodos Se estudiaron 60 pacientes pediatricos atendidos en el Servicio de Gastroenterologia por manifestar sintomas de dispepsia. Ninguno referia haber tomado antibioticos, inhibidores de la bomba de protones, ni compuestos con sales de bismuto. A todos ellos se les realizo la prueba del aliento con 13C-urea, una determinacion de IgG anti-H.pylori, se les practico una endoscopia gastrointestinal con la finalidad de obtener muestras para estudio histologico, prueba de la urea inmediata y cultivo microbiologico, y se les recogio una muestra fecal para estudiar la presencia de antigeno de H.pylori. Resultados Cuarenta y siete de los 60 pacientes estudiados mostraron estar infectados por H.pylori. En todos se aislo el microorganismo del cultivo y la prueba del aliento fue positiva. En 45 de ellos se positivizo la prueba HpSA (95,7%). No hubo ningun falso positivo de esta tecnica. Conclusiones La prueba HpSA ademas de la buena sensibilidad (95%) y especificidad (100%) que ha manifestado en este estudio, aporta ventajas sobre las otras tecnicas no invasoras, por su simplicidad en la obtencion de la muestra, realizacion de la tecnica, rapidez en la obtencion de los resultados y bajo coste economico, al compararlo con el elevado coste de la prueba del aliento.

Direct detection of Streptococcus pneumoniae in positive blood cultures by real-time polymerase chain reaction

We developed a real-time polymerase chain reaction specific for Streptococcus pneumoniae to be applied directly from blood culture bottles without previous DNA extraction step. For the 128 blood culture bottles tested, the assay had 94% and 98.4% sensitivity and specificity, respectively. This assay provides rapid and accurate identification of this pathogen.

Aumento de la resistencia a macrólidos mediada por metilasas en Streptococcus pyogenes en un hospital pediátrico de Barcelona

Introduccion Estudiamos los mecanismos geneticos y la evolucion de la resistencia de S. pyogenes a claritromicina y clindamicina (1996-2003) en 480 aislamientos pediatricos de un hospital de Barcelona. Resultados Se observa un aumento progresivo de cepas con fenotipo MLSB (55,6% de los aislamientos resistentes en 2002) y una disminucion relativa del fenotipo M. El porcentaje global de resistencia a macrolidos fue del 29,8% (27,4% en el periodo 1996-2001 y 35,8% en 2002-2003). Se detecto el gen mefA en las cepas con fenotipo M, el gen ermB en las cepas con fenotipo MLSB constitutivo y el gen ermTR en algunas cepas con fenotipo MLSB inducible. Conclusion El aumento de la resistencia y los cambios en los mecanismos implicados reducen la efectividad de macrolidos y clindamicina como tratamiento alternativo.