title: Arrangement and number of clustered regularly interspaced short palindromic repeat spacers are associated with erythromycin susceptibility in emm12, emm75 and emm92 of group A streptococcus.
abstract: Clustered regularly interspaced short palindromic repeats (CRISPR) are composed of numerous repeat-spacer units and are considered a prokaryotic defence system against foreign nucleic acids. Since antibiotic-resistant genes are frequently encoded in foreign nucleic acids, the aim of this study was to test whether erythromycin susceptibility in group A streptococcus (Streptococcus pyogenes) is associated with characteristics of CRISPR elements. Erythromycin susceptibility of 330 isolates collected between 1997 and 2003 was analysed. Among 29 emm types, emm12, emm75 and emm92 showed significant changes in erythromycin-resistance rates. By sequencing the spacers from two CRISPR loci, spacer contents in emm12, emm75 and emm92 strains were associated with erythromycin susceptibility. Strains with fewer spacers were more resistant to erythromycin. Moreover, in emm4 strains, which showed no significant change in their annual erythromycin-resistance rate, CRISPR type and number of spacers were not correlated with erythromycin susceptibility. These results highlight a novel association between CRISPR spacer content and erythromycin susceptibility in group A streptococcus.
authors.affiliation: Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: P-X
authors.initials: PX
authors.lastname: Zheng
authors.forename: C
authors.initials: C
authors.lastname: Chiang-Ni
authors.forename: S-Y
authors.initials: SY
authors.lastname: Wang
authors.forename: P-J
authors.initials: PJ
authors.lastname: Tsai
authors.forename: C-F
authors.initials: CF
authors.lastname: Kuo
authors.forename: W-J
authors.initials: WJ
authors.lastname: Chuang
authors.forename: Y-S
authors.initials: YS
authors.lastname: Lin
authors.forename: C-C
authors.initials: CC
authors.lastname: Liu
authors.forename: J-J
authors.initials: JJ
authors.lastname: Wu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D064112:Clustered Regularly Interspaced Short Palindromic Repeats; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004917:Erythromycin / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004917:Erythromycin
keywords: Clustered regularly interspaced short palindromic repeats; epidemiology study; erythromycin; group A streptococcus; macrolide