Genotyping of clinical methicillin-susceptible Staphylococcus aureus isolates in a Dutch teaching hospital.

Methicillin-susceptible Staphylococcus aureus isolates, recovered from 204 patients in our hospital in a 22-month period, were characterized by pulsed-field gel electrophoresis. Among the multiple S. aureus types six clonal lineages dominated, comprising isolates from 158 patients. Despite the limited genetic variation, cross-transmission was made plausible only sporadically.

Multiresistant Staphylococcus epidermidis in a neonatal care unit.

OBJECTIVE: To study the presence and diversity of types of Staphylococcus epidermidis in the neonatal intensive care unit of a university hospital. METHODS: During a period of 6 weeks, samples were taken from nose, external auditory canal, axilla, groin and umbilicus from consecutively admitted patients. Patients were sampled two times a week for up to 2 weeks. Isolates of S. epidermidis were characterized by antibiogram, plasmid pattern and biotype. RESULTS: Fifteen patients were included. Each patient was sampled in one to four successive surveys, depending on the admission period. A total of 128 isolates of S. epidermidis were obtained and allocated to seven antibiogram types, 36 plasmid types and 14 biotypes. One plasmid type found in 58 isolates (six patients) corresponded with one multiresistant antibiogram type. The number of isolates with these characteristics increased per neonate from the first survey to the fourth. Nineteen isolates from four patients were allocated to a second plasmid type and were of a common antibiogram type. The remaining 34 plasmid types were sporadic. No clear correspondence of biotypes with antibiogram or plasmid types was found. CONCLUSIONS: The present study revealed the increase in colonization of a multiresistant type of S. epidermidis in the compromised patients during admission to the ward. Further studies have to assess whether this type remains persistent in the ward.