Identity and prevalence of multilocus sequence typing-defined clones of group A streptococci within a hospital setting.
Between July and October 2003, 121 clinical isolates of group A streptococci (GAS) were collected from a London hospital and characterized by multilocus sequence typing (MLST) to determine the identity and prevalence of clones circulating within this setting. A total of 39 sequence types (ST), of which 20 were represented by a single isolate, were identified. The eight most prevalent clones among the 121 GAS were ST117/emm81 (16%), ST39/emm4 (9%), ST62/emm87 (7%), ST28/emm1 (6%), ST36/emm12 (6%), ST46/emm22 (5%), ST334/emm82 (5%), and ST101/emm89 (4%). Compared to those in the MLST database (http://spyogenes.mlst.net), 12 (31%) of the 39 STs had not been previously identified, although 7 of these differed from recognized STs at only a single locus, suggesting they were closely related to previously recognized strains. Resistance to erythromycin and tetracycline was seen in 7 and 20% of isolates, respectively, with four isolates resistant to both agents. GAS strains with higher (>80) emm types accounted for 45% of GAS isolates collected during this study. Continuing GAS surveillance, using easily comparable methods, is important for detecting changes in the character of disease-causing isolates.
McGregor
Karen F
KF
Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, St. Mary's Hospital Medical School, Norfolk Place, London W2 1PG, UK.
Spratt
Brian G
BG
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D002352:Carrier Proteins / Q000235:genetics; D004917:Erythromycin / Q000494:pharmacology; D006786:Hospitals, Urban; D006801:Humans; D008131:London; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000145:classification* / Q000235:genetics; D013752:Tetracycline / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein; D004917:Erythromycin; D013752:Tetracycline