Human Infections Due toStreptococcus dysgalactiaeSubspeciesequisimilis

Abstract

Human streptococci that belong to Streptococcus dysgalactiae subspecies equisimilis (SDSE) have long been known under the name of beta-hemolytic groups C and G streptococci. Extensive taxonomic studies during the past years have distinguished most of the veterinary pathogens belonging to Lancefield groups C and G from those of human origin. After being considered nonpathogenic for many years, SDSE is now recognized as an important bacterial pathogen. The clinical spectrum of diseases caused by this species closely resembles Streptococcus pyogenes infections, including the occurrence of poststreptococcal sequelae. In accordance with these observations, many of the virulence factors present in S. pyogenes can also be found in SDSE strains. High nucleotide-sequence identities in virulence genes and the association of these genes with mobile genetic elements support the hypothesis of extensive horizontal gene-transfer events among streptococcal species of the pyogenic group. Recent epidemiological studies have shown increasing numbers of invasive SDSE infections, often among immunocompromised patients, and suggest that this species will probably gain even more clinical importance in the near future. For a better understanding of the changing epidemiology and pathogenicity of SDSE, an increased awareness of these microorganisms as human pathogens and proper identification are mandatory.

Eritrodermia con bacteriemia por Streptococcus dysgalactiae subespecie equisimilis en un paciente pediátrico: reporte de un caso y revisión de la literatura

“…Comparte una gran similitud en su genoma con S. pyogenes (hasta 63%) 4 en relación a los factores de virulencia. Dentro de éstos, se encuentran estreptolisina O y S; super-antígenos (SpeA, SpeC, SpeM) e inactivadores del complemento (C5a peptidasa y estreptoquinasa) 5 (Tabla 1). Recientemente se ha descrito la presencia de una bacteriocina llamada disgalacticina, que estaría dirigida contra S. pyogenes, otorgándole una ventaja ecológica a SDSE en el hospedero.…”

“…Su transmisión es por contacto persona-persona y las infecciones zoonó-ticas son comparativamente infrecuentes. Se han descrito brotes comunitarios e intrahospitalarios 5 .…”

“…Se describe resistencia a macrólidos (16-24%), a tetraciclinas (60%) y existen algunos reportes de resistencia a fluoroquinolonas. No se ha descrito resistencia a vancomicina o linezolid 5 .…”

A CD46 transgenic mouse model for studying the histopathology of arthritis caused by subcutaneous infection with Streptococcus dysgalactiae subspecies equisimilis

“…S. dysgalactiae subsp. equisimilis is now thought to cause a range of infections, from relatively mild to severe life-threatening invasive diseases, such as acute pharyngitis, pyoderma, cellulitis, wound infections, abscesses, erysipelas, necrotizing fasciitis (NF), septic arthritis, vertebral osteomyelitis, septicaemia, multiple organ failure and streptococcal toxic shock syndrome (Brandt & Spellerberg, 2009;Broyles et al, 2009;Sing et al, 2001). Many of these indications can show substantial overlap with those of patients infected with group A streptococcus (GAS).…”

“…GAS and S. dysgalactiae subsp. equisimilis have been shown to share many of the same virulence-related genes, including emm (Brandt & Spellerberg, 2009;Davies et al, 2007;Shimomura et al, 2011). Accordingly, in the present study we aimed to develop a CD46 Tg mouse model of S. dysgalactiae subsp.…”