Abstract
The level of total extracellular neuraminidase produced by 74 clinical isolates of group B streptococci isolated from diseased or asymptomatically colonized infants was assayed. Extracellular neuraminidase was obtained from concentrated filtrates of exponentially growing cultures of group B streptococci grown in a chemically defined medium (FMC) containing supplemental protein. The total activity of extracellular enzyme produced by these clinical isolates ranged from <10 to 360 nmol of sialic acid released per min per mg of cell dry weight. Strains were arbitrarily classified as either nonproducers (<10 nmol/min per mg of cell dry weight), low producers (>10 to ≤140 nmol/min per mg of cell dry weight), or high producers (>140 to 360 nmol/min per mg of cell dry weight). Type III isolates from diseased infants were significantly more often classified as high producers than strains of group B streptococci of other serotypes from diseased infants (P<<0.001). Furthermore, the serotype III strains isolated from neonatal infections were more often high producers than those of the same serotype from asymptomatically colonized infants (P<0.025). These results suggest that the ability to produce elevated levels of neuraminidase may be related to the frequent association of type III strains with disease among neonates.
Original language | English (US) |
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Pages (from-to) | 738-746 |
Number of pages | 9 |
Journal | Infection and immunity |
Volume | 21 |
Issue number | 3 |
DOIs | |
State | Published - 1978 |
ASJC Scopus subject areas
- Parasitology
- Microbiology
- Immunology
- Infectious Diseases