INVESTIGATION OF MICROCOCCACEAE IN A DEPARTMENT OF CARDIAC SURGERY

Abstract

A total of 965 strains of Micrococcaceae isolated from 200 patients, personnel, and air in a department of cardiac surgery were classified by means of Baird‐Parker's scheme. The majority of strains were identified as Staphylococcus epidermidis (S. epidermidis) biotype 1, but S. epidermidis biotype 4 accounted for c. 25% of isolates from patients post‐operatively. Pre‐operative isolates were generally sensitive to most antibiotics tested while post‐operative strains of coagulase‐negative Micrococcaceae from patients and isolates from personnel and air were frequently multiply‐resistant. Strains of Staphylococcus aureus (S. aureus) were sensitive or resistant only to penicillin. More patients were colonized with coagulase‐negative Micrococcaceae after operation than at admission to the hospital (p <0.001), while the frequency of S. aureus carriers was the same before and after operation and equal to the frequency found earlier. The frequency of S. aureus carriers among the personnel, however, was lower than reported earlier (10%). Multiply‐resistant strains of S. epidermidis seem to have replaced resistant strains of S. aureus as the predominant hospital saprophyte among Micrococcaceae.

Etiologic Importance of Coagulase‐Negative Micrococcaceae Isolated from Blood Cultures

“…All coagulase-negative isolates were identified and classified according to the scheme of Baird-Parker, as described elsewhere (8).…”

Studies On Coagulase‐Negative Staphylococci In Patients Undergoing Cardiac Surgery

“…Bio-typing. One hundred and thirty-two isolates were classified and bio-typed according to the scheme of Baird-Parker, as described elsewhere (9). Twenty-three isolates primarily classified as S. epidermidis biotype 4 were tested for ability to ferment mannitol anaerobically.…”