Serum from dairy cows was tested for inhibitory effect on penicillinase from a penicillin-resistant Staphylococcus aureus strain of mastitic origin. Among cows with subclinical mastitis caused by penicillin-resistant S. aureus there was a significantly higher frequency of individuals with penicillinajse-inhibiting serum than among healthy cows. Among the subclinical cases, a foregoing penicillin treatment of clinical mastitis appeared to increase the serum antipenicillinase activity.
Serum fra mjølkekyr ble testet for inhiberende effekt overfor penicillinase fra en penicillin-resistent Staphylococcus aureus-stamme isolert fra bovin mastitt Blant kyr med subkliniisk mastitt forårsaket av penicillin-resistent S. aureus var det en signifikant høyere frekvens av individer med penicillinase-inhiberende serum enn blant friske kyr. Blant de subkliniske tilfellene syntes en forutgående behandling for klinisk mastitt å øke serum-antipenicillinaseaktiviteten.