Characterization of the NAD-glycohydrolase in streptococcal strains.
The NADase (Nga) of group A streptococci (GAS) has been implicated in the pathogenesis of diseases such as streptococcal toxic shock-like syndrome (STSS) and necrotizing fasciitis. In this study we found that the proportion of NADase-positive strains among clinical isolates in Japan has increased over time. The GAS strains studied could be divided into three groups: strains lacking NADase activity, strains with low NADase activity, and strains with high NADase activity. The older strains, isolated before 1989, belonged to the 'no activity' group. Analysis using GST-Nga recombinants revealed that nga alleles of representative older strains encode inactive Nga. Mutational analysis of the GST-Nga recombinants suggested that residue 330 could be associated with reduced activity, based upon deduced amino acid sequences. We also investigated NADase activity of streptococcal strains other than GAS. All group G streptococcal isolates from STSS patients possessed nga genes encoding active enzymes.
Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
Ichiro
I
Tatsuno
Department of Molecular Bacteriology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho Showa-ku, Nagoya 466-8550, Japan.
Jun
J
Sawai
Department of Molecular Bacteriology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho Showa-ku, Nagoya 466-8550, Japan.
Akira
A
Okamoto
Department of Microbiology, Aichi Prefectural Institute of Public Health, Nagare 7-6, Tsuji-machi, Kita-ku, Nagoya 462-8576, Japan.
Masakado
M
Matsumoto
Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
Masaaki
M
Minami
Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
Masanori
M
Isaka
Department of Molecular Bacteriology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho Showa-ku, Nagoya 466-8550, Japan.
Michio
M
Ohta
Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
Tadao
T
Hasegawa
D000595:Amino Acid Sequence; D001483:Base Sequence; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008969:Molecular Sequence Data; D009244:NAD+ Nucleosidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015995:Prevalence; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013291:Streptococcus / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification
D011994:Recombinant Proteins; D009244:NAD+ Nucleosidase