Antimicrobial use and colonization with erythromycin-resistant Streptococcus pnemoniae in Greece during the first 2 years of life

We evaluated nasopharyngeal colonization with erythromycin-resistant Strept ococcus pneumoniae during the first 2 years of life in central and southern Greece. Of 2448 children studied from February 1997 to February 1999, 766 (31%) carried 781 pneumococcal isolates. Ninety-five (3.9%) of the children attended day care centers. Eighteen percent of the pneumococci were resist ant to erythromycin (minimal inhibitory concentration I to >128 mug/mL), wi th 67.9% of them carrying the erm(B) gene and 29.2% mef(A) gene products. F our strains possessed neither the erm(B) nor the mef(A) gene. Multidrug res istance occurred in 97% and 40% of isolates carrying the erm(B) and mef(A) gene, respectively An association was found between the erm(B) gene and ser otypes 6B and 23F and between the mef(A) gene and serotypes 14 and 19F A si gnificant relationship existed between carriage of erythromycin-resistant p neumococci and use of macrolides or beta -lactams in the previous 3 months; the association was strongest when macrolide therapy was administered duri ng the last month (odds ratio, 5.92; P=.0001), The findings indicate the ne cessity of a judicious use of both macrolides and lactams in young children to reduce the colonization with erythromycin-resistant pneumococci and the subsequent spread of such strains to the community.