[Hyalurodinase activity of beta-hemolytic streptococci of the Lancefield group C].

This study examines the hyaluronidase activity levels of different strains of Lancefield group C beta-hemolytic streptococci, predominantly found in horses, as established using two distinct test methods. The results illustrate discernible differences between the three Streptococcus species and their capacity to produce hyaluronidase.

Research Methodology

• A total of 110 strains of Lancefield group C beta-hemolytic streptococci obtained from horses (comprising 71 S. zooepidemicus, 27 S. equisimilis and 12 S. equi strains) and 5 additional reference strains, were tested to assess their hyaluronidase production ability.
• The evaluations were conducted in two different test environments, a culture test with agarose gel and a liquid turbidity test following the DiFerrante methodology.
• Parallel tests confirming the hyaluronidase activity in the S. equisimilis strains were also conducted via determination of final N-acetyl-D-glucosamine groups and additional turbidity tests.

Research Findings

• The findings from both test methods demonstrated that the three Straptococcus species possessed differences in their relative quantitative hyaluronidase activity.
• S. equisimilis strains were noted to produce 5 to 10 times more hyaluronidase than the S. zooepidemicus strains.
• Conversely, the S. equi strains did not show any enzyme production.
• The results obtained from complimentary hyaluronidase activity tests (N-acetyl-D-glucosamine group determination and turbidity tests) on S. equisimilis strains showed a high level of correlation, with a correlation index of 0.93, thereby confirming the reliability and consistency of these multiple test methods.

Conclusion

• This research successfully differentiates the three Streptococcus species based on their relative quantitative hyaluronidase activity, thereby highlighting the significant range in their enzyme production capabilities.
• This insight could potentially be useful in developing targeted treatments for infections caused by these different streptococcus species in horses, by customizing the therapies based on the specific hyaluronidase activity of the strain.