Antimicrobial susceptibility of Streptococcus pneumoniae from children attending day-care lefts in a central Italian city

Objective To undertake a survey of nasopharyngeal carriage of Streptococcus pneumoniae , which reflects strains causing infection, in 100 children under 3 years of age attending day-care lefts in Frosinone, a city near Rome. Methods Fifty-three unique isolates of S. pneumoniae , isolated from 41 of the children tested, were tested for antimicrobial susceptibility to penicillin, cefotaxime, erythromycin, clindamycin, tetracycline, chloramphenicol and trimethoprim–sulfamethoxazole. Results Resistance rates were as follows: penicillin, 20.7% (15% intermediate; 5.7% resistant); trimethoprim–sulfamethoxazole, 64.2%; erythromycin, 64.2%; clindamycin, 30.2%; tetracycline, 32.1%; and chloramphenicol, 3.8%. Except for three intermediate strains, all strains were susceptible to cefotaxime. Only five strains were susceptible to all of the antibiotics tested. An unusual finding of this study was that 23 of the 34 erythromycin-resistant strains were penicillin susceptible, whereas erythromycin-resistant strains found in other countries are predominantly penicillin resistant as well. In addition, 18 of the 34 erythromycin-resistant strains were susceptible to clindamycin. Serogroups 6, 14, 19 and 23 accounted for 84.9% of the isolates. Conclusions These data show that carriage of antibiotic-resistant pneumococci in children under 3 years of age is high in Frosinone, Italy. Information on resistance rates in pneumococcal disease in different age groups and on prevalence of drug resistance in other parts of the country is urgently needed.