Clinical and Molecular Characteristics of Invasive and Noninvasive Skin and Soft Tissue Infections Caused by Group A Streptococcus

Abstract

The severity of skin and soft tissue infections caused by group A Streptococcus (GAS) is variable, and there are only a limited number of studies evaluating the characteristics of these infections in the literature. From May 2005 to November 2007, 73 patients with skin and soft tissue infections caused by group A Streptococcus were included in this study. Among these patients, 34 (46.6%) had invasive diseases. Diabetes mellitus, alcoholism, and hypertension were the most common underlying disorders. The overall mortality rate was 6.8%, and the elderly were predisposed to invasive infections (P < 0.001). Neutrophil percentages of >80, serum creatinine levels of >2 mg/dl, and high serum C-reactive protein levels were noted more frequently in patients with invasive infections than in patients with noninvasive infections, as were bacteremia and a high mortality rate. Of the 73 isolates, 93.2%, 97.3%, and 37% exhibited susceptibility to erythromycin, clindamycin, and tetracycline, respectively. The five most prevalent emm types were emm106 (24.7%), emm11 (12.3%), emm102 (9.6%), emm4 (8.2%), and emm12 (8.2%). Compared to other types, the emm106 type was significantly more likely to be associated with invasive diseases (P ‫؍‬ 0.012). Dendrogram analysis showed a unique SmaI-digested pulsed-field gel electrophoresis pattern of the emm106 type that was particularly prone to cause invasive skin and soft tissue infections (P < 0.001). The results of this study suggest that isolates with the emm106 gene may be an emerging group A Streptococcus strain that causes invasive skin and soft tissue infections. Further surveillance study to understand the significance of this invasive strain is critical.Group A Streptococcus (GAS), also known as Streptococcus pyogenes, is a Gram-positive coccus that is arranged in pairs and chains. These organisms are ubiquitous in the environment and are responsible for a broad spectrum of human infections that result in significant morbidity and mortality, including pharyngitis, scarlet fever, skin and soft tissue infection (SSTI), streptococcal toxic shock syndrome, septicemia, pneumonia, and meningitis (10). It is estimated that severe GAS diseases lead to more than 500,000 deaths each year via infections such as acute rheumatic fever, rheumatic heart disease, poststreptococcal glomerulonephritis, and invasive diseases (6).SSTIs are common and account for approximately 7 to 10% of hospitalizations in North America (12, 13). The manifestations of SSTIs caused by GAS range from mild superficial impetigo, erysipelas, pyoderma, and cellulitis to life-threatening necrotizing fasciitis or myonecrosis. The early discrimination between noninvasive SSTIs that can be resolved with antimicrobial treatment and invasive infections that may additionally require surgical intervention is critical. Unfortunately, the clinical symptoms and signs of invasive SSTIs, including disproportionate pain, bullae, ecchymosis, sloughing, skin anesthesia, rapid progression, gas in the tissue, and systemic toxicity, often ap...

Epidemiology and Molecular Characterization of Macrolide-Resistant Streptococcus pyogenes in Taiwan

“…Other than one study which reported that emm106 was one of the prevalent emm types in invasive GAS in New Caledonia (34), this emm type has not been reported in other countries. However, two studies in Taiwan found emm106 to be highly associated with invasive skin and soft tissue infections (28,30). Although we do not have information on the disease manifestations, we did find a strong association of emm106 with abscess/pus isolates.…”

“…Three studies on invasive GAS, one from France, one from 11 European countries, and the other from the United States, also found emm1 to be the leading emm type among invasive GAS isolates (25)(26)(27). Previous studies from Taiwan have also found emm1, emm4, emm12, and emm11 to be among the prevalent emm types, but their proportions varied in different disease entities and populations (28)(29)(30). However, emm28, a leading emm type in Western countries associated with ERY-resistant GAS (5,25,26,31), was detected in only one of the ERY r isolates in the present study.…”

Hyaluronan Breakdown Contributes to Immune Defense against Group A Streptococcus

“…Skin and soft tissue infections occur frequently and range in severity from minor self-limiting superficial infections to lifethreatening invasive diseases (1,2). Uncomplicated superficial skin infections are often self-limited or can be managed effectively with topical or oral antibiotic treatment.…”

Immunization with a streptococcal multiple-epitope recombinant protein protects mice against invasive group A streptococcal infection

“…However, the prevalent emm types of GAS isolated from patients with invasive soft tissue infection or streptococcal toxic shock syndrome in Taiwan are emm 1, emm4 , emm11 , emm12 , and emm102 types [11, 12]. In vitro , the M-protein specific opsonization of GAS was enhanced by anti-rFSBM serum (Fig 4B), and in vivo protection against intraperitoneal emm1 , emm4 , emm12 , and emm22 types of GAS infection was achieved after rFSBM vaccination (Fig 6B).…”

“…In contrast, a higher diversity of emm types has been found in Africa and Pacific regions [4, 6]. In Taiwan, the leading emm types of GAS isolated from invasive infection are emm1 , emm4 , emm11 , emm12 , and emm102 [11, 12]. M protein consists of an N-terminal variable domain and a conserved C-terminal domain.…”