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Polyclonal Population Structure of Streptococcus pneumoniae Isolates in Spain Carrying mef and mef plus erm(B)▿

de la Pedrosa, Elia Gómez G.; Morosini, María-Isabel; van der Linden, Mark; Ruiz-Garbajosa, Patricia; Galán, Juan Carlos; Baquero, Fernando; Reinert, Ralf René; Cantón, Rafael
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
27.513406%
The population structure (serotypes, pulsed-field gel electrophoresis [PFGE] types, and multilocus sequencing types) of 45 mef-positive Streptococcus pneumoniae isolates [carrying mef alone (n = 17) or with the erm(B) gene n = 28)] were studied. They were selected from among all erythromycin-resistant isolates (n = 244) obtained from a collection of 712 isolates recovered from different Spanish geographic locations in the prevaccination period from 1999 to 2003. The overall rates of resistance (according to the criteria of the CLSI) among the 45 mef-positive isolates were as follows: penicillin G, 82.2%; cefotaxime, 22.2%; clindamycin, 62.2%; and tetracycline, 68.8% [mainly in isolates carrying erm(B) plus mef(E); P < 0.001]. No levofloxacin or telithromycin resistance was found. Macrolide resistance phenotypes (as determined by the disk diffusion approximation test) were 37.7% for macrolide resistance [with all but one due to mef(E)] and 62.2% for constitutive macrolide-lincosamide-streptogramin B resistance [cMLSB; with all due to mef(E) plus erm(B)]. Serotypes 14 (22.2%), 6B (17.7%), 19A (13.3%), and 19F (11.1%) were predominant. Twenty-five different DNA patterns (PFGE types) were observed. Our mef-positive isolates were grouped (by eBURST analysis) into four clonal complexes (n = 18) and 19 singleton clones (n = 27). With the exception of clone Spain9V-3...

Characterization of Macrolide Efflux Pump mef Subclasses Detected in Clinical Isolates of Streptococcus pyogenes Isolated between 1999 and 2005▿

Blackman Northwood, J.; Del Grosso, M.; Cossins, L. R.; Coley, M. D.; Creti, R.; Pantosti, A.; Farrell, D. J.
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
27.513406%
The macrolide efflux mechanism of resistance, mef, was characterized in community-acquired respiratory tract infections with Streptococcus pyogenes. Fifty-four (4.6%) M phenotype isolates were screen tested as negative for mef(A). Of these 54 isolates, 5 (0.4%), 27 (2.3%), and 1 (0.1%) were considered to be mef(I) positive, a novel mosaic variant of mef, or a novel subclass of mef, respectively. This study shows (i) the definitive presence of mef(E) in S. pyogenes and its global distribution, (ii) the presence of a mosaic variant of mef composed of mef(A) and mef(E), (iii) the previously undescribed presence of mef(I) in S. pyogenes, and (iv) the presence of a novel subclass of mef in S. pyogenes.