Prospective study of the invasive strains of Streptococcus pneumoniae isolated in 16 hospitals in Cataluna, Spain
Latorre, C.; Sierra, M.; Lite, J.
Enfermedades Infecciosas y Microbiologia Clinica 17(6): 286-291
1999
ISSN/ISBN: 0213-005X PMID: 10439539 Document Number: 504923
The increasing penicillin resistance rates of Streptococcus pneumoniae led us to review the strains isolated from usually sterile sources during 1996 in 16 hospitals of Cataluña. A card was designed for the prospective collection of patients' data. Susceptibility to penicillin, cefotaxime and erytromicin, as well as serotypes, were studied. 237 S. pneumoniae strains were isolated from patients aged from one month to 95 years (19% younger than 5 years), 9.7% of adult patients being HIV antibodies carriers. Global penicillin resistance was of 35.4% (27.4% with minimal inhibitory concentration [MIC] between 0.1 and 1 microgram/ml and and 8.0% > 1 microgram/ml), but it was only of 25% in strains causing meningeal infections, and of 34.1% in those involved in respiratory processes. Paediatric patients less than five years old had a higher resistance rate (47.7%), as well as octagenarian ones (44.7%), but HIV+ patients had a lower rate (30.4%). 12.2% of strains (10% of meningeal ones) showed some degree of cefotaxime resistance but only five of them (none from meningeal origin) reached a MIC of 2 micrograms/ml. Global erythromicin resistance was 17.7% (17.1% in strains causing respiratory infections). Prevalent serotypes were 6, 9 and 14. The high percentage of strains, mainly from paediatric patients, with diminished penicillin, cefotaxime and erythromicin susceptibility among those causing meningitis and respiratory infections, alerts of possible therapeutic failures if empiric treatments are established in infections produced by this microorganism. For this reason, nowadays it is necessary the routine study of the susceptibility of all pathogen strains of pneumococci. Most strains (208 out of 216) causing invasive disease in our area belong to serotypes covered by the present 23-valent vaccine.