title: Extracellular deoxyribonucleases of streptococci: a comparison of their occurrence and levels of production among beta-hemolytic strains of various serological groups.
abstract: Production of extracellular deoxyribonuclease by 394 strains of beta hemolytic streptococci was examined employing a deoxyribonucleic acid-methyl green assay. Enzymatic activities were measured in supernatants of bacterial cultures. Of the strains tested, 316 (80%) produced the enzyme. Nuclease production was demonstrated in 100% of group A strains and in 85, 74 and 58% of groups B, C and G, respectively. Levels of nuclease activity were then evaluated statistically. The analysis of variance showed that group A strains produced more enzyme than did streptococci of groups B, C or G. Group B strains produced less nuclease than did isolates of groups C or G. There was no significant difference in the levels of nuclease produced by groups C and G or by the various serological types of group B streptococci. Human group C strains produced more enzyme than animal strains.
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, Federal University, Rio de Janeiro, Brazil.
authors.forename: B T
authors.initials: BT
authors.lastname: Ferreira
authors.forename: L C
authors.initials: LC
authors.lastname: Benchetrit
authors.forename: A C
authors.initials: AC
authors.lastname: De Castro
authors.forename: T G
authors.initials: TG
authors.lastname: Batista
authors.forename: L
authors.initials: L
authors.lastname: Barrucand
mesh_terms: D000818:Animals; D003851:Deoxyribonucleases / Q000096:biosynthesis / Q000378:metabolism*; D005110:Extracellular Space / Q000201:enzymology; D006801:Humans; D012703:Serotyping; D013045:Species Specificity; D013291:Streptococcus / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification
chemical_list: D003851:Deoxyribonucleases