Similar environmental survival patterns of Streptococcus pyogenes strains of different epidemiologic backgrounds and clinical severity

The spectrum of Streptococcus pyogenes (group A streptococci) infections and complications includes asymptomatic carriage, throat infection, and acute rheumatic fever, localized skin, soft tissue or bone infections, and invasive spread with positive blood cultures accompanied by toxic shock leading to rapid death [1–5]. The contagiousness of these S. pyogenes infections has been studied extensively [1–3] and the contribution of environmental sources has been considered [1, 5]. Following a nosocomial outbreak at our hospital due to an S. pyogenes strain [4] in which some findings paralleled those from earlier MRSA outbreaks [6], we decided to examine the survival of S. pyogenes strains in the environment to ascertain whether extended environmental survival contributes to the organism’s spread, as noted for a number of MRSA outbreak strains at our hospital [7]. Thus, several S. pyogenes strains of different epidemiological backgrounds and clinical severity were selected, and the survival behavior of each was evaluated. All of the S. pyogenes strains studied were diagnosed at the Atrium Medical Centre (AMC) and the German National Reference Laboratory for Streptococci at the Department of Medical Microbiology at the RheinischWestfalische Technische Hochschule (RWTH) in Aachen, Germany. They were all obtained from clinical cases, and the cases reflected a wide spectrum of clinical severity or epidemiological behavior. The strains were divided into two groups and four patient subgroups: group A included strains from serious invasive infections (i.e., bacteremia, sepsis, including the manifestation of toxic shock syndrome), with subgroup 1 (strains 1 and 2) being nosocomial and subgroup 2 (strains 3 and 4) non-nosocomial;