Highly variable penicillin resistance determinants PBP 2x, PBP 2b, and PBP 1a in isolates of two Streptococcus pneumoniae clonal groups Poland(23F)-16 and Poland(6B)-20

作者：Izdebski Radoslaw; Rutschmann Jens; Fiett Janusz; Sadowy Ewa; Gniadkowski Marek; Hryniewicz Waleria^*; Hakenbeck Regine

来源：Antimicrobial Agents and Chemotherapy, 2008, 52(3): 1021-1027.

DOI：10.1128/AAC.01082-07

Penicillin-binding proteins (PBPs) in representatives of two Streptococcus pneumoniae clonal groups that are prevalent in Poland, Poland(23F)-16 and Poland(6B)-20, were investigated by PBP profile analysis, antibody reactivity pattern analysis, and DNA sequence analysis of the transpepticlase (TP) domain-encoding regions of the pbp2x, pbp2b, and pbpla genes. The isolates differed in their MICs of beta-lactam antibiotics. The majority of the 6B isolates were intermediately susceptible to penicillin (penicillin MICs, 0.12 to 0.5 mu g/ml), whereas all 23F isolates were penicillin resistant (MICs, >= 2 mu g/ml). The 6B isolates investigated had the same sequence type (ST), determined by multilocus sequence typing, as the Poland(6B)-20 reference strain (ST315), but in the 23F group, isolates with three distinct single-locus variants (SLVs) in the ddl gene (ST173, ST272, and ST1506) were included. None of the isolates showed an identical PBP profile after labeling with Bocillin FL and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and only one pair of 6B isolates and one pair of 23F isolates (ST173 and ST272) each contained an identical combination of PBP 2x, PBP 2b, and PBP la TP domains. Some 23F isolates contained PBP 3 with an apparently higher electrophoretic mobility, and this feature also did not correlate with their STs. The data document a highly variable pool of PBP genes as a result of multiple gene transfer and recombination events within and between different clonal groups.

• 出版日期2008-3