BACTERIAL CHARACTERIZATION - IDENTIFICATION AND ANTIBIOTIC SUSCEPTIBILITY OF NOCARDIA-FARCINICA AND NOCARDIA-NOVA IN THE UK

Nocardia asteroides has long been recognised as a heterogeneous group of organisms. The description and identification of two new subgroups, N. farcinica and N. nova, in other countries encouraged us to re-exam ine a collection of N. asteroides isolates from the UK. Of 73 clinical isolates identified as N. asteroides from different parts of England and Wales during 1991-1993, and now subjected to further differentiati on tests by the N. Mycobacterial/Nocardial Reference Laboratory, 15 (2 0.5%) were identified as farcinica based on three out of four characte ristics: growth property, acetamide production, rhamnose assimilation and a distinct antibiogram. No isolates were identified as N. nova. A revised identification and susceptibility system has significant clini cal and taxonomic implications. Its introduction will improve speciati on, identify antibiotic resistance and influence the choice of safer a lternative therapy for patients infected with Nocardia spp. in the UK.