An isogenic mutant of Streptococcus pyogenes Manfredo that lacks the ability to make streptococcal acid glycoprotein (SAGP) has been constructed by inserting a deletion in the sagp gene using the method of allelic exchange. An assay of cell extracts (CE) prepared from the wild-type and mutant Manfredo strains for the enzyme arginine deiminase (AD) showed that significant activity was present in wild-type CE but none could be detected in mutant CE. These findings confirm our earlier conclusion that SAGP has AD activity (B. Wild-type CE but not mutant CE potently inhibited human peripheral blood mononuclear cell proliferation in response to phytohemagglutinin, and this inhibition was overcome by the addition of L-arginine to proliferation assay mixtures. Invasion assays showed that the isogenic mutant organisms lacking SAGP, and thus AD activity, were between three and five times less able to enter epithelial cells (Hep-2C and A549) than were the wild-type streptococci. Both wild-type and mutant S. pyogenes bacteria were extremely sensitive to low pH. However, L-arginine (1 mM or above) significantly increased the viability of the wild type but not the isogenic mutant organisms under acidic conditions. The difference in acid susceptibility between wild-type and mutant bacteria may explain the reduced capacity of the isogenic mutant bacteria to invade and survive intracellularly.AStreptococcus pyogenes (group A Streptococcus) is an important human pathogen, infections with which can lead to acute disorders such as pharyngitis, erysipelas, otitis media, and impetigo or to pathogenic sequelae including glomerulonephritis, acute rheumatic fever and reactive arthritis (6,7,21,29,42,53). In the last decade there has been a dramatic resurgence in the incidence of serious streptococcal infections; in particular, the number of cases of streptococcal toxic shock syndrome, bacteremia, and necrotising fasciitis has increased (11). A greater understanding of the ways in which this pathogen interacts with the host, the virulence factors that it produces, and the identification of possible targets for vaccine design are required.During a previous study, it was observed that cell extracts (CE) prepared from a wide range of S. pyogenes strains potently inhibited antigen-, superantigen-, or phytohemagglutinin (PHA)-stimulated human peripheral blood mononuclear cell (PBMC) proliferation in vitro (16,17). Purification of the inhibitory component present in CE of S. pyogenes Manfredo by anion-exchange chromatography followed by gel filtration chromatography yielded a single protein. When sequenced, this protein was found to have an NH 2 -terminal sequence identical to streptococcal acid glycoprotein (SAGP), which had been isolated from S. pyogenes Su (23,24,56,57). SAGP has 31 to 39% amino acid identity to arginine deiminase (AD) from Mycoplasma hominis, Mycoplasma arginini, Pseudomonas putida, and Pseudomonas aeruginosa (3). It was subsequently shown that CE obtained from several group A streptococcal strains all contained AD activit...
Disease status scores in AS correlated significantly with anxiety, depression, internality and health status. Interpretation of AS disease scores should take an account of psychological status and the choice of measures used. These findings have important potential applications in AS management and monitoring, including the identification of patients for biological therapies.
Our results confirm previous reports of a high rate of relapse of gastrointestinal symptoms following recovery from an acute episode of cryptosporidiosis and show that C. hominis but not C. parvum is associated with an increased risk of nonintestinal sequelae. This study demonstrates that the impact of cryptosporidiosis on public health extends beyond that of the acute diarrheal illness and can lead to significant health sequelae.
entheses easily accessible to clinical examination. This included entheses known to be involved in AS together with sites of possible involvement. The following sites were examined: the nuchal crests, the manubriosternal joint, the costochondral joints, the greater tuberosity and the medial and lateral epicondyles of the humerus, the iliac crests and the anterior superior iliac spines, the greater trochanter of the femur, the tibial tuberosities, the adductor tubercles, the medial and lateral condyles of the femur and tibia, the head of the fibula, the calcaneal insertions of the plantar fascia and the achilles tendons, the sacroiliac joints, the cervical, thoracic, and lumbar spinous processes, the ischial tuberosities, and the anterior posterior iliac spines.A scoring system was developed based on the patients' response to firm palpation over these entheses. Some of the sites were scored individually, whereas others were scored as a group, the highest scoring site being recorded for the group as a whole. The sites which were grouped in this way were: the nuchal crests, the costochondral joints, the sacroiliac joints, and the cervical, thoracic, and lumbar spinous processes. The remaining sites were scored individually left and right.
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