Bacteriemia neumocócica en pacientes adultos de un hospital de Madrid: serotipos y sensibilidad antibiótica

espanolIntroduccion. El objetivo de este estudio es describir la distribucion de los serotipos de Streptococcus pneumoniae, su sensibilidad antimicrobiana y su relacion con las vacunas en cepas de neumococo aisladas en hemocultivo de pacientes adultos. Metodos. Se estudiaron un total de 67 cepas de S. pneumoniae. El serotipado se realizo mediante aglutinacion con particulas de latex sensibilizadas y la reaccion de Quellung. La concentracion minima inhibitoria (CMI) frente a penicilina, eritromicina, cefotaxima y levofloxacino se determino mediante E-test. Resultados. Los serotipos mas prevalentes entre las 67 cepas fueron 22F (11,9%) y 3 (11,9%), seguidos de 7F (7,5%) y 19A (7,5%). Los porcentajes de cepas cubiertas por la vacuna neumococica 7-valente (VNC7V), vacuna neumococica 13-valente (VNC13V) y vacuna polisacarida 23-valente (VNP23V) fueron respectivamente de 16, 49 y 82%. Los serotipos 22F y 3 ocasionaron en conjunto 14 de los 48 episodios de neumonia bacteriemica (29,2%) y solo 2 de los de los 19 episodios (10,5%) de bacteriemia sin neumonia. Segun el criterio del CLSI del 2007, 12 cepas (17,9%) fueron no sensibles a penicilina. Once de estas 12 cepas (91,7%) fueron simultaneamente resistentes a eritromicina. Conclusiones. Los serotipos mas comunes fueron 22F, 3, 7F y 19A. Tres de ellos (3, 7F y 19A) son serotipos cubiertos por la VNC13V pero no por la VNC7V. El serotipo 22F es un serotipo emergente no cubierto por la VNC7V. Los porcentajes de no sensibilidad a penicilina y resistencia a eritromicina se encontraron en margenes comparables a los informados en nuestro pais. EnglishIntroduction. The aim of this study is to describe the distribution of Streptococcus pneumoniae serotypes, its antimicrobial susceptibility profiles and the relation with vaccines in pneumococcal invasive strains isolated from blood cultures of adult patients. Methods. All pneumococci isolated (67 strains) from blood cultures were serotyped by latex agglutination (Pneumotest latex) and Quellung reaction (Statens Serum Institut, Denmark). Antimicrobial susceptibility testing to penicillin (PEN), cefotaxime (CT), erythromycin (ERY) and levofloxacin (LEV) was performed by the E-test method (Biomerieux, France). Results. Among the 67 strains isolated, the most prevalent serotypes were 22F (11.9%) and 3 (11.9%), the second most frequent were 7F (7.5%) and 19A (7.5%). The coverage of the strains by the pneumococcal 7-valent conjugate vaccine (VNC7V), pneumococcal 13-valent conjugate vaccine (VNC13V) and pneumococcal 23-valent polysaccharide (VNP23V) were 16, 49 and 82%, respectively. Serotypes 22F and 3 were responsible for 14 of the 48 episodes of pneumonia with bacteremia (29.2%) and only 2 of the 19 episodes (10.5%) of bacteremia without pneumonia. According to the 2007 CLSI criteria, 12 strains (17.9%) were non-susceptible to penicillin. Eleven of this 12 strains (91.7%) were resistant to erythromycin, simultaneously. Conclusions. The most common serotypes were 22F, 3, 7F y 19A. Three of them (3, 7F y 19A) are serotypes that are covered by the new VNC13V but not by VNC7V. Serotype 22F is a serotype emergent that is not covered by the VNC7V. The percentage of non-susceptibility to penicillin and resistance to erythromycin was comparable to the percentage reported in our country.