Streptococcus pyogenes secretes several proteins that influence host-pathogen interactions. A tissue-culture model was used to study the influence of the secreted cysteine protease streptococcal erythrogenic toxin B (SPE B) on the interaction between S. pyogenes strain NZ131 (serotype M49) and mammalian cells. Inactivation of the speB gene enhanced fibronectin-dependent uptake of the pathogen b...

Obsessive-compulsive disorder (OCD) is a debilitating disorder for which the cause is not known and treatment options are modestly beneficial. A hypothesis is presented wherein the root cause of OCD is proposed to be a dysfunction of the gut microbiome constituency resulting in a susceptibility to obsessional thinking. Both stress and antibiotics are proposed as mechanisms by which gut microbio...

Several microbial pathogens have been reported to interact with glycosaminoglycans (GAGs) on cell surfaces and in the extracellular matrix. Here we demonstrate that M protein, a major surface-expressed virulence factor of the human bacterial pathogen, Streptococcus pyogenes, mediates binding to various forms of GAGs. Hence, S. pyogenes strains expressing a large number of different types of M p...

Pseudomonas aeruginosa causes devastating chronic pulmonary infections in cystic fibrosis (CF) patients. Although the CF airway is inhabited by diverse species of microorganisms interlaced within a biofilm, many studies focus on the sole contribution of P. aeruginosa pathogenesis in CF morbidity. More recently, oral commensal streptococci have been identified as cohabitants of the CF lung, but ...

Streptococcal toxic shock syndrome (STSS) is a highly lethal, acute-onset illness that is a subset of invasive streptococcal disease. The majority of clinical STSS cases have been associated with the pyrogenic toxin superantigens (PTSAgs) streptococcal pyrogenic exotoxin A or C (SPE A or C), although cases have been reported that are not associated with either of these exotoxins. Recent genome ...

Lymphocyte transformation studies of nonadherent lymphocytes from chronic Chagasic and uninfected persons demonstrated that responses of all individuals to a mouse heart homogenate showed a correlation with responses to streptococcal antigens. Considering the known cross-reactions between streptococcal and cardiac antigens and the high reactivity of Chagasic patients to streptococcal antigens, ...

We describe the case of a 48-year-old man with an acute nephritis and respiratory failure. Clinical history, streptococcal antibody titres and renal biopsy led to a diagnosis of post-streptococcal glomerulonephritis. Respiratory investigations excluded pulmonary oedema and infection. We hypothesize that this man had a co-existing post-streptococcal glomerulonephritis and an immune-mediated pneu...

BACKGROUND Group B streptococcal disease is one of the most common infections in the first week after birth. In 2002, national guidelines recommended universal late antenatal screening of pregnant women for colonization with group B streptococcus to identify candidates for intrapartum chemoprophylaxis. METHODS We evaluated the implementation of the guidelines in a multistate, retrospective co...

Background: “Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections”, or PANDAS, is a syndrome characterized by acute-onset obsessive-compulsive disorder (OCD) and/or tics accompanied by the neuropsychiatric symptoms. This case is reported because of its rarity. Case report: A 6.5-year-old boy with swollen tonsils, high-grade fever and rash was admitted to Ami...