title: Characterization of recombinant fluoroquinolone-resistant pneumococcus-like isolates.
abstract: Fourteen fluoroquinolone-resistant streptococcal isolates with recombinant DNA topoisomerase genes, preliminarily identified as pneumococci, were further characterized using phenotypic and genotypic approaches. Phenotypic tests classified them as atypical pneumococci. Phylogenetic relationships were analyzed by using the sequences of seven housekeeping alleles from these isolates and from isolates of Streptococcus pneumoniae, Streptococcus mitis, Streptococcus oralis, and Streptococcus pseudopneumoniae. Four isolates grouped with S. pneumoniae, seven grouped with S. pseudopneumoniae, and three grouped with S. mitis. These results generally agreed with those obtained with an optochin susceptibility test and with the organization of the atp operon chromosomal region, encoding the F(o)F(1) H(+)-ATPase (the target of optochin). All seven isolates grouping with S. pseudopneumoniae share the same spr1368-atpC-atpA gene order; all four grouping with S. pneumoniae share the spr1368-IS1239-atpC-atpA order, and two out of the three grouping with S. mitis share the spr1284-atpC-atpA order. In addition, evidence for recombination within the seven housekeeping alleles of the S. pseudopneumoniae population was provided by several methods: the index of association (0.4598, P < 0.001), the pairwise homoplasy index, and the split-decomposition method. This study confirms the existence of pneumococci among the alpha-hemolytic streptococci with DNA topoisomerase genes showing a mosaic structure and reveals a close relationship between atypical pneumococci and S. pseudopneumoniae.
authors.affiliation: Unidad de Genética Bacteriana, Centro Nacional de Microbiología, Instituto de Salud Carlos III and CIBER de Enfermedades Respiratorias, Majadahonda. luzbal@isciii.es
authors.forename: Luz
authors.initials: L
authors.lastname: Balsalobre
authors.forename: Montserrat
authors.initials: M
authors.lastname: Ortega
authors.forename: Adela G
authors.initials: AG
authors.lastname: de la Campa
mesh_terms: D000483:Alleles; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015373:Bacterial Typing Techniques; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D026942:DNA Topoisomerases / Q000235:genetics / Q000378:metabolism; D020043:Genes, Essential; D005838:Genotype; D009876:Operon; D010641:Phenotype; D010802:Phylogeny; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism; D011803:Quinine / Q000031:analogs & derivatives* / Q000494:pharmacology; D011995:Recombination, Genetic; D013291:Streptococcus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D034361:Streptococcus mitis / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D019533:Streptococcus oralis / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C017303:ethylhydrocupreine; D011803:Quinine; D006180:Proton-Translocating ATPases; D026942:DNA Topoisomerases