ENTEROTOXIN AND TOXIC-SHOCK-SYNDROME TOXIN-1 PRODUCTION OF METHICILLIN-RESISTANT AND METHICILLIN-SENSITIVE STAPHYLOCOCCUS-AUREUS STRAINS

In this study the production of enterotoxin A-D and toxic shock syndro me toxin-l (TSST-1) of 181 methicillin resistant (MRSA) and 100 methic illin sensitive (MSSA) Staphylococcus aureus first isolates from diffe rent patients was investigated. All the MRSA- and MSSA isolates in the study were collected in a period between 1993 and 1995 from specimens sent from 11 different acute care hospitals in the greater Dusseldorf area. As far as possible the isolates were matched according to ward and hospital. The isolates were collected in the same time period and matched for specimen from which isolated. Furthermore, only first isol ates were analysed in both groups. No significant difference in the pr oduction of toxin of any type between MRSA and MSSA could be detected (51 and 40% respectively). When the individual toxins were analysed, a gain no significant difference between MRSA and MSSA was demonstrable (enterotoxin production by MRSA 40% and MSSA 36%, and TSST-1 16% and 8 % respectively). Despite this, a slight tendency for MRSA to produce e nterotoxin A and B and for MSSA to produce enterotoxin C was observed. In addition, generation of TSST-1 by both groups was independent of e nterotoxin A-D production. Interestingly, no increase in the proportio n of TSST-1- or enterotoxin-producing MRSA and MSSA isolates was obser ved in strains isolated from blood cultures from patients with a clini cal diagnosis of sepsis. Genotypical pulsed-field-gel-electrophoresis (PFGE) and phenotypical (bacteriophage typing, lysotyping) characteriz ation of the 181 MRSA isolates resulted in 28 different PFGE patterns (of which 19 were toxin producers) and 22 lysotyping groups (18 of whi ch produced toxin). In summary, the investigated clinical S. aureus is olates showed no difference in their ability to produce toxin and this was independent of their sensitivity to methicillin.