Reemergence of emm 1 and a Changed Superantigen Profile for Group A Streptococci Causing Invasive Infections: Results from a Nationwide Study

Abstract

Between 1999 and 2002, 496 invasive group A streptococcal (GAS) isolates from clinical microbiological departments in Denmark and subsequently 487 (98%) questionnaires from the clinicians treating the patients were received as part of a national surveillance. emm types and streptococcal superantigen (SAg) genes were determined. The incidence of invasive GAS infections was on average 2.3 per 100,000 per year. Bacteremia with no focal symptoms (27%) was together with erysipelas (20%) the most prevalent clinical diagnoses. Streptococcal toxic shock syndrome occurred in 10% of patients, of which 56% died. The overall case fatality rate within 30 days was 23%. In total, 47 different emm types were identified, of which emm1, emm3, emm4, emm12, emm28, and emm89 were identified in 72% of the 493 available isolates. During the 4-year period the presence of emm1 increased from 16% in 1999 to 40% in 2002. Concurrently, the presence of emm3 decreased from 23% in 1999 to 2% in 2002. The emm1 isolates predominantly carried speA, although the frequency decreased from 94% in 1999 to 71% in 2002, whereas the emm1-specific prevalence of speC increased from 25 to 53%. In a historical perspective, this could be interpreted as a reemergence of emm1 and could indicate a possible introduction of a new emm1 subclone. However, this reemergence did not result in any significant changes in the clinical manifestations during the study period. Our results show the complexity of invasive GAS infections, with time-dependent variations in the incidence and distribution of emm and SAg genes, which emphasizes the need for continuous epidemiological and molecular investigations.

Clinical and Epidemiological Aspects of Invasive Streptococcus pyogenes Infections in Denmark during 2003 and 2004

“…In the same time, emm3 increased from 2% in 2002 to 20% in 2004. Thus, the distribution of emm1 and emm3 was changing over time, which could be at least in part related to epidemic waves (2) and to (17). A prominent role of emm28 strains in invasive GAS disease was also reported in Sweden and Finland, as well as in the United States (19,36,40,45).…”

emm Types, Virulence Factors, and Antibiotic Resistance of Invasive Streptococcus pyogenes Isolates from Italy: What Has Changed in 11 Years?

“…A sudden increase in the numbers of invasive emm1 isolates with a contemporary change in the superantigen-associated repertoire (decrease of emm1-speA strains and increase of emm1-speC strains) has been interpreted to result from the possible introduction of a new emm1 subclone in Denmark (18). The repertoire of erythrogenic toxin genes analyzed in the present study was limited to the most often investigated speA and speC toxin gene profile, but no evident change in their prevalence among either the invasive emm1 or emm3 strains isolated was noted.…”

“…Given the fluctuations in the serotype distribution over time, emm1 isolates were the most prevalent in The Netherlands from 1994 to 2003, followed by emm3, emm89, emm28, emm12, and emm6 (37), as well as in Denmark, where a trend for increasing numbers of emm1 isolates in the years from 1999 to 2002 was noted (17,18). An increasing number of M-nontypeable GAS isolates from patients with invasive diseases observed during the years from 2000 to 2002 in the United Kingdom belonged to higher M phenotype-type numbers, including emm89 and the newly designated emm types (35).…”

Sudden Death Caused by Fulminant Bacterial Infection: Background and Pathogenesis of Japanese Adult Cases

“…Pulmonary congestion complicated by bacterial colonization was observed (Fig. 3) (20)(21)(22)(23). Four of the seven patients showed adrenocortical hemorrhage (24).…”

“…The cause of death in each case is circulatory collapse caused by fulminant infection (10,19 (3,4,(20)(21)(22)(23)(31)(32)(33)(34)(35)(36)(37). The onset of fulminant infection depends on the bacteria and the sensitivity of the host (38).…”