Molecular typing of Streptococcus pneumoniae in northeastern Romania: Unique clones of S-pneumoniae isolated from children hospitalized for infections and from healthy and human immunodeficiency virus-infected children in the community

Microbiologic, serologic, and molecular typing techniques were used to char acterize 272 isolates of Streptococcus pneumoniae colonizing or infecting c hildren in Iasi, Romania, during a surveillance study conducted in 1996-199 8. The 574 children in the study were from the following groups: healthy ch ildren attending 2 institutions, healthy children hospitalized for elective surgery, hospitalized children with pneumococcal infections, and human imm unodeficiency virus (HIV)-infected children in an orphanage. Pneumococci co lonizing healthy children from closed communities showed close similarities to pneumococci from children with pneumococcal infections; they expressed a limited number of similar serotypes, showed high frequency of penicillin and multidrug resistance, and shared several common clonal types. In contra st, isolates recovered from healthy children hospitalized for elective surg ery expressed a large variety of serotypes, were less frequently resistant to antimicrobial agents, and showed great genetic diversity. Pneumococcal f lora colonizing HIV-infected children showed a more complex epidemiology. T hese observations suggest a possible epidemiologic connection between the f lora of S. pneumoniae colonizing healthy children in closed communities and the flora found in children hospitalized for infection.