Nomenclature of major antimicrobial-resistant clones of Streptococcus pneumoniae defined by the pneumococcal molecular epidemiology network

The emergence of disease caused by penicillin-resistant and multidrug-resis tant pneumococci has become a global concern, necessitating the identificat ion of the epidemiological spread of such strains. The Pneumococcal Molecul ar Epidemiology Network was established in 1997 under the auspices of the I nternational Union of Microbiological Societies with the aim of characteriz ing, standardizing, naming, and classifying antimicrobial agent-resistant p neumococcal clones. Here we describe the nomenclature for 16 pneumococcal c lones that have contributed to the increase in antimicrobial resistance wor ldwide. Guidelines for the recognition of these clones using molecular typi ng procedures (pulsed-field gel electrophoresis, BOX-PCR, and multilocus se quence typing.) are presented, as are the penicillin-binding profiles and m acrolide resistance determinants for the 16 clones. This network can serve as a prototype for the collaboration of scientists in identifying clones of important human pathogens and as a model for the development of other netw orks.