Most staphylococcal strains are exopenicillinase producers, and some of them are inducible with penicillins. Investigation of these beta-lactamases induced with cephalosporins is of interest from a clinical point of view. We selected 8 exopenicillinase producing staphylococci to study their pI values with chromatofocusing technique. We wished to study the enzymes of Staphylococcus aureus PCl, Staph. aureus NCTC 9789 and three congenic methicillin resistant (MK) and sensitive (MS) pairs of Staph. aureus 5814, Staph. aureus 1 190 and Staph. aureus DU 4916. Due to firm binding of the enzymes to the polybuffer exchanger (PBE) 94, it was impossible to assess directly the pI values in most of the cases. However, elution of the enzymes in pure form was possible with 1 M NaCl allowing good preparative runs with high yield. Only the MR Staph. aureus 5814 strain produced inducible and eluable enzymes. With methicillin as inducer, a pI = 6.5 exopenicillinase, and with cephalexin a pl = 5.3 enzyme were obtained. When cefamandole or ceftriaxone were the inducers we found two enzymes with pI = 5.3 and pI = 7.0.
|Number of pages||5|
|Journal||International Journal of Experimental and Clinical Chemotherapy|
|Publication status||Published - Jan 1 1991|
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