1999 Volume 73 Issue 9 Pages 893-900
Recently. in Japan newly neonatal exanthematous disease was elucidated to be caused by staphyloccocal superantigcnic exotoxins, mainly TSST-1.
We studied exotoxins producibility of 43 strains ofS. aureusisolated from neonates with exanthematous disease and examined antibody titers to staphylococcal enterotoxin A, B, C (SEA, SEB, SEC) and toxic shock syndrome toxin 1 (TSST-1) of the patients and control (umbilical cord blood from term infants). The results were as follows
1. 34 of 43 strains (79%) isolated from the patients were SEC and TSST-1 producing MRSA, 5 strains (12%) were SEB, SEC, and TSST-1 producing MRSA, 1 strain (2%) was SEB and TSST-1 producing MRSA, 2 strains (12%) were SEB producing MSSA and did not produce TSST-1. The 1 strain (2%) was MSSA which produced SEC and TSST-1
2. 16 neonates with exanthematous disease, who showed typical clinical signs and laboratry findings of thrombocytopenia, with SEC and TSST-1 producing MRSA isolates had significantly low anti-TSST-1 antibody titers at onset (p<0.05), compared with the control (umbilical cord blood from term infants): TSST-1 appeared to the causative agent for the disease.
In two neonates with exanthematous disease, with SEB-and non-TSST-1--producing MSSA isolates, anti-SEB antibody titers were low at onset, so SEB appeared to the causative agent for the disease.
3. In Japan, low anti-TSST-1 antibody titers were found in the umbilical blood samples from about 70% of term infants; and low anti-SEB or anti-SEC antibody titers were found in samples from only about 10% of them, that is, a number of term infants had anti-SEB and anti-SEC antibodies.
The majority of S. aureus isolated from neonates with exanthematous disease were enterotoxinand TSST-1-producing MRSAs.
The results of our study by measuring antitoxin antibody titers suggested that SEB and SEC might not be pathogenically responsible, but TSST-1 was considered to be responsible for the majority of exanthematous disease.
Prevalence of TSST-1-producing MRSA in the neonatal and premature baby ward is the main cause for the high incidence of this disease in Japan, whereas the low antibody titer to TSST-1 in the mother, in comparison with the anti-enterotoxin antibody titers, may also be a predisposing factor.