TESTING THE EFFICACY OF A MOLECULAR SURVEILLANCE NETWORK - METHICILLIN-RESISTANT STAPHYLOCOCCUS-AUREUS (MRSA) AND VANCOMYCIN-RESISTANT ENTEROCOCCUS-FAECIUM (VREF) GENOTYPES IN 6 HOSPITALS IN THE METROPOLITAN NEW-YORK-CITY AREA

Molecular fingerprinting techniques are rapidly becoming indispensable tools for hospital epidemiology, On the other hand, the relative comp lexity and unfamiliarity of these techniques to most hospital diagnost ic laboratories limit their usefulness, In an attempt to provide a sol ution for this dilemma, we tested the feasibility and efficacy of a co operative venture in which molecular typing of isolates recovered from patients in six hospitals was performed at two microbiology research laboratories with expertise in these techniques, In a small preliminar y study, 30 methicillin-resistant Staphylococcus aureus (MRSA) and 30 vancomycin-resistant Enterococcus faecium (VREF) isolates were collect ed over a 3-week period from six hospitals in the metropolitan New Yor k area and transported to the Laboratory of Microbiology at The Rockef eller University during the summer months of 1994, Nineteen of the 27 confirmed MRSA isolates mere closely related strains carrying the same mecA and the same Tn554 polymorphs in a pulsed-field gel electrophore sis (PFGE) background represented by closely related subtypes of a sin gle pattern, indicating the wide distribution of this MRSA clone among the participating hospitals, Typing of the same 27 MRSA isolates was also performed at the Tuberculosis Center of the Public Health Researc h Institute and identical results were obtained, The 29 confirmed VREF isolates were highly heterogeneous and belonged to as many as 23 dist inct clonal types as defined by PFGE patterns and probing with vanA. C haracterization of the 60 isolates by these methods was completed in o ne month of full-time effort by a single experienced laboratory assist ant guided by a doctoral-level expert in molecular fingerprinting tech niques, The collection of samples for both MRSA and VREF was not inten ded to address epidemiological questions but to determine the feasibil ity of a multicenter study, On the basis of our preliminary findings w e are encouraged that a larger cooperative effort is possible and with the correct sampling method we believe that epidemiological and surve illance studies could be accomplished that would provide a tracking sy stem to assist hospitals, clinics, and chronic care facilities in cont rolling the spread of multidrug-resistant pathogens.