Molecular emm genotyping and antibiotic susceptibility of Streptococcus dysgalactiae subsp. equisimilis isolated from invasive and non-invasive infections.
To analyse the characteristics of infections caused by Streptococcus dysgalactiae subsp. equisimilis, clinical isolates (n=145) were collected at 11 medical institutions between September 2003 and October 2005. These isolates belonged to Lancefield group A (n=5), group C (n=18) or group G (n=122). Among all isolates, 42 strains were isolated from sterile samples such as blood, synovial fluid and tissue specimens from patients who were mostly over 50 years with invasive infections, and included seven cases of streptococcal toxic shock syndrome and necrotizing fasciitis. In contrast, the remaining 103 were isolated mainly from patients of all age groups with non-invasive infections such as pharyngotonsillitis. These isolates were classified into 25 types based on emm genotyping. A significant difference in emm types was observed between isolates from invasive and non-invasive infections (P<0.001): stG485, stG6792 and stG2078 predominated among isolates from invasive infections. A phylogenetic tree of complete open reading frames of emm genes in this organism showed high homology with those of Streptococcus pyogenes, but not with those of other streptococci. The presence of five different clones was estimated based on DNA profiles of isolates from invasive infections obtained by PFGE. Genes for resistance to macrolides [erm(A), three isolates; erm(B), five isolates; mef(A), seven isolates] and levofloxacin (mutations in gyrA and parC, four isolates) were identified in this organism. These results suggest the need for further nationwide surveillance of invasive infections caused by S. dysgalactiae subsp. equisimilis.
Sunaoshi
Katsuhiko
K
Department of Clinical Microbiology, Saitama Institute of Public Health, Saitama PR, Japan.|Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
Murayama
Somay Y
SY
Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
Adachi
Keiko
K
Laboratory Medicine, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan.
Yagoshi
Michiko
M
Department of Bacteriological Examination, Nihon University Itabashi Hospital, Tokyo, Japan.
Okuzumi
Katsuko
K
Division of Infection Control, Department of Medical Safety Administration, Dokkyo University School of Medicine Hospital, Tochigi PR, Japan.
Chiba
Naoko
N
Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
Morozumi
Miyuki
M
Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
Ubukata
Kimiko
K
Department of Clinical Microbiology, Saitama Institute of Public Health, Saitama PR, Japan.|Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D002648:Child; D024881:Drug Resistance, Bacterial; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010802:Phylogeny; D013290:Streptococcal Infections / Q000382:microbiology*; D013291:Streptococcus / Q000187:drug effects* / Q000235:genetics*; D055815:Young Adult
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins