Necrotizing soft tissue infections caused by Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis of groups C and G in western Norway. (25th June 2013)

• Record Type: Journal Article
• Authors: Bruun, T.; Kittang, B. R.; de, B. J.; Aardal, S.; Flaatten, H. K.; Langeland, N.; Mylvaganam, H.; Vindenes, H. A.; Skrede, S.; Allerberger, F.
• Is Part Of: Clinical microbiology and infection. Volume 19:Number 12(2013:Dec.)
• Page Start: E545
• Page End: E550
• Publication Date: 2013-06-25
• Subjects: Medical microbiology -- Periodicals; Diagnostic microbiology -- Periodicals; Communicable diseases -- Periodicals; Infection -- Periodicals; 616.01
• DOI: 10.1111/1469-0691.12276
• Languages: English
• ISSNs: 1198-743X

Abstract

<abstract abstract-type="main" id="clm12276-abs-0001"> <title>Abstract</title> <p> <italic>Streptococcus pyogenes</italic> (group A streptococcus, GAS) is a major cause of necrotizing soft tissue infection (NSTI). On rare occasions, other β‐haemolytic streptococci may also cause NSTI, but the significance and nature of these infections has not been thoroughly investigated. In this study, clinical and molecular characteristics of NSTI caused by GAS and β‐haemolytic <italic>Streptococcus dysgalactiae</italic> subsp. <italic>equisimilis</italic> of groups C and G (GCS/GGS) in western Norway during 2000–09 are presented. Clinical data were included retrospectively. The bacterial isolates were subsequently <italic>emm</italic> typed and screened for the presence of genes encoding streptococcal superantigens. Seventy cases were identified, corresponding to a mean annual incidence rate of 1.4 per 100 000. Sixty‐one of the cases were associated with GAS, whereas GCS/GGS accounted for the remaining nine cases. The in‐hospital case fatality rates of GAS and GCS/GGS disease were 11% and 33%, respectively. The GCS/GGS patients were older, had comorbidities more often and had anatomically more superficial disease than the GAS patients. High age and toxic shock syndrome were associated with mortality. The Laboratory Risk Indicator for Necrotizing Fasciitis laboratory score showed high values (≥6) in only 31 of 67 cases. Among the available 42 GAS isolates, the most predominant <italic>emm</italic> types were <italic>emm</italic>1, <italic>emm</italic>3 and <italic>emm</italic>4. The virulence gene profiles were strongly correlated to <italic>emm</italic> type. The number of superantigen genes was low in the four available GCS/GGS isolates. Our findings indicate a high frequency of streptococcal necrotizing fasciitis in our community. GCS/GGS infections contribute to the disease burden, but differ from GAS cases in frequency and predisposing factors.</p> </abstract>