Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Unencapsulated variants of encapsulated, M-protein-positive group A streptococci are oxygen sensitive and secrete inhibitory concentrations of hydrogen peroxide when grown in aerated broth cultures. The organisms were equally sensitive to hydrogen peroxide, and neither exhibited catalase or peroxidase activity, suggesting that differences in oxygen sensitivity reflect dissimilarity in oxygen uptake. The encapsulated parental culture was found to grow in aggregates that take up oxygen more slowly than unencapsulated, oxygen-sensitive derivatives. Moreover, the latter grow in an unaggregated, homogenous suspension. The enzyme hyaluronidase was able to disrupt aggregates of the encapsulated strain increase the rate that these cells take up oxygen, and cause the accumulation of toxic concentrations of hydrogen peroxide earlier in their growth cycle. The evidence presented shows that the aggregation of streptococcal cells by their hyaluronic acid capsule provides this organism with a novel means to avoid self-destruction by oxygen metabolites--cells are shielded from oxygen. The reduced surface-to-volume ratio and limited diffusion of oxygen into the interior of aggregates are proposed as the protective mechanism.
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PMID:Hyaluronic acid capsule: strategy for oxygen resistance in group A streptococci. 39 98

Cultures of Streptococcus equisimilis (Lancefield group C) from three outbreaks of illness were found to carry the T-protein antigen 204. Strains of this type were not otherwise represented in a collection of 743 cultures of these 'pyogenes-like' streptococci isolated from other outbreaks of infection or as random isolates. Two of the three outbreaks were of pharyngitis. The third arose in a maternity unit where the organism was isolated from mothers with puerperal fever, from staff and also from the environment. Representative strains were found to carry M-protein antigens as judged by their ability to survive and multiply in fresh normal human blood. Comparison of absorbed rabbit antiserum to the M antigens in opsonic and precipitin tests showed that a distinct M antigen was present on isolates from one outbreak of sore throat and that all cultures from the other two incidents shared a common M antigen. Samples of serum were also available from patients in the outbreak of puerperal sepsis. Most patients developed antibodies to one or more streptococcal antigens including the M protein, streptolysin O, streptokinase and the hyaluronidase specific for strains of group C and group G streptococci.
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PMID:The presence of M proteins in outbreak strains of Streptococcus equisimilis T-type 204. 280 34

Group A streptococci from parent cultures (PC) of six different serotypes were selected by rotation with human blood (RHB) or by serial passage via intraperitoneal inoculation in mice (MP). M-protein content of PC, RHB and MP streptococci of each serotype was determined in quintuplicate by radial immunodiffusion against type-specific antisera. Hyaluronic acid content was determined in quintuplicate colorimetrically after treatment of streptococci with hyaluronidase. Data were subjected to variance analysis. LD(50) for mice of PC, RHB and MP streptococci, inoculated intraperitoneally, was also determined. It was observed that MP streptococci virulent for mice were rich in M-protein and hyaluronic acid. However, RHB streptococci of M-protein and hyaluronic acid content similar to MP streptococci were not virulent for mice. This dichotomy with respect to mouse virulence infers the existence of as yet unidentified streptococcal virulence factors, in addition to M-protein and capsule.
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PMID:On the virulence of group A streptococci: evidence for virulence factors other than M-protein and capsule. 471 25