Molecular Epidemiology of Penicillin-Susceptible, Multidrug-Resistant Serotype 6B Pneumococci Isolated from Children in Greece

• Published in: Journal of Clinical Microbiology
• Main Authors: Syrogiannopoulos, G. A., Bogaert, D., Grivea, I. N., Beratis, N. G., De Groot, R., Hermans, P. W. M.
• Format: Text
• Language: English
• Published: American Society for Microbiology 2001
• Subjects: Bacteriology; Iceland
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC87779; http://www.ncbi.nlm.nih.gov/pubmed/11158110; https://doi.org/10.1128/JCM.39.2.581-585.2001

Since January 1996, and over a 3-year time span, a significant spread of serotype 6B multidrug-resistant (MDR) pneumococci, susceptible to penicillin and resistant to erythromycin, clindamycin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole, was noted in young carriers living in central and southern Greece. Using restriction fragment end labeling and penicillin binding protein (PBP) genotyping, we studied 41 serotype 6B penicillin-susceptible MDR pneumococci isolated during two independent studies in Greece. Forty (98%) of these 41 isolates were strongly related, representing a single lineage (genetic relatedness, ≥91%). The Greek isolates were closely related (genetic relatedness, ∼91%) to the penicillin-resistant MDR clone of serotype 6B that spread from Spain to Iceland in the late 1980s. Moreover, the Greek group of isolates was genetically distinct (genetic relatedness, ≤83%) from other penicillin-susceptible or -resistant serotype 6B strains from various parts of the world. All serotype 6B penicillin-susceptible MDR isolates displayed a penicillin-susceptible PBP 1A-2B-2X genotype. Our findings suggest that the penicillin-susceptible MDR 6B clone that was found in Greece between the years 1996 and 1999 represents the ancestor of the pandemic penicillin-resistant MDR clone 6B.