Nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae, and antibiotic susceptibilities in children attending day-care centers.

This study had for aim to determine the incidence of nasopharyngeal carriage and the antibiotic susceptibility of Streptococcus pneumoniae and Haemophilus influenzae in children attending daycare centers. In June 1996 and June 1997, nasal swabs were obtained in 521 children bewteen 3 months and 2 years of age, in 16 day-care centers in the North East France. Streptococcus pneumoniae and Haemophilus sp. were found in 48.2% and 44.1% of the children respectively (H. influenzae 33.2%, others 10.9%). Among Streptococcus pneumoniae strains, 99.5% were susceptible to rifampicin but only 42.5% were susceptible to penicillin. Resistance to erythromycin, cotrimoxazole, and doxycyclin was detected in 43.9%, 21.5%, and 22.4%, respectively, in these penicillin-susceptible (PS) strains. 57.5% of Streptococcus pneumoniae strains presented a reduced susceptibility to penicillin (PSDP), and in this group, only 2 isolates had an amoxicillin MIC superior to 2 mg/L. When compared to PS strains, PSDP strains presented cross-resistance to the same molecules with an increased frequency. Resistance of Haemophilus sp. to amoxicillin was detected in 63.5% of the strains, due to penicillinase production. These strains, however, remained susceptible to amoxicillin-clavulanic acid and ceftriaxone. (C) 2000 Editions scientifiques et medicales Elsevier SAS.