Gradual increase in the minimum inhibitory concentration of penicillin among both susceptible and resistant Streptococcus pneumoniae isolates from Greek children during 1995-1997

A total of 140 non-replicate Streptococcus pneumoniae community isolates fr om Greek children collected during the period 1995-1997 were studied. Combi ned intermediate and high penicillin resistance rates were 23% in 1995, 29% in 1996, and 27% in 1997. The proportion of highly resistant isolates stea dily increased from 2% in 1995 to 12% in 1997. There was no significant dif ference in penicillin resistance rates among colonizing and infecting isola tes (23 and 27%, respectively). Over the study period, a clear shift toward s higher penicillin MIC was observed among both the susceptible and resista nt groups. Thus, penicillin resistance rates were equally high among coloni zing and infecting isolates and resistance levels appeared to be gradually increasing throughout the entire S. pneumoniae population. (C) 1999 Elsevie r Science B.V. and International Society of Chemotherapy. All rights reserv ed.