Molecular epidemiology of nga and NAD glycohydrolase/ADP-ribosyltransferase activity among Streptococcus pyogenes causing streptococcal toxic shock syndrome.
Severe invasive group A streptococcal (GAS) infections emerged in the late 1980s, yet no single virulence factor has been common to all isolates from infected patients. A strong association was recently found between isolates of such cases (regardless of M type) and the production of NAD glycohydrolase (NADase). Of interest, all M-1 strains isolated after 1988 were positive for NADase, whereas virtually all M-1 GAS were previously negative for NADase. Genetic analysis demonstrated that GAS isolates were >96% identical in nga and >99% identical in their upstream regulatory sequences. Furthermore, because NADase-negative strains did not produce immunoreactive NADase, we concluded that additional regulatory element(s) control NADase production. NADase purified from GAS altered neutrophil-directed migration and chemiluminescence responses and had potent ADP-ribosyltransferase activity. In summary, the temporal relationship of NADase expression, alone or with other streptococcal virulence factors, may contribute to the pathogenesis of invasive GAS infections.
Stevens
D L
DL
Infectious Disease Section, Veterans Affairs Medical Center, Boise, ID 83702, USA. dlsteven@primenet.com
Salmi
D B
DB
McIndoo
E R
ER
Bryant
A E
AE
D000595:Amino Acid Sequence; D001483:Base Sequence; D002634:Chemotaxis, Leukocyte; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009244:NAD+ Nucleosidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012703:Serotyping; D012772:Shock, Septic / Q000382:microbiology*; D013290:Streptococcal Infections / Q000453:epidemiology*; D013297:Streptococcus pyogenes / Q000145:classification / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity; D014774:Virulence
D009244:NAD+ Nucleosidase