INCREASE IN MULTIPLE ANTIBIOTIC-RESISTANCE IN NONTYPHOIDAL SALMONELLAS FROM HUMANS IN ENGLAND AND WALES - A COMPARISON OF DATA FOR 1994 AND1996

The incidence of multiple drug resistance (to four or more antimicrobi als) in salmonellas from humans in England and Wales in 1996 has been compared with corresponding data for 1994. For Salmonella enteritidis multiple resistance has remained rare, although a high proportion of i solates of phage type 6A have shown resistance to ampicillin, For S. t yphimurium multiple resistance has continued to increase, with 81% of isolates now multiresistant, Of particular importance in S. typhimuriu m has been the continued epidemic of multiresistant DT 104 and the inc reasing occurrence of strains of this phage type with additional resis tance to trimethoprim and/or ciprofloxacin, For S. virchow, a 10% incr ease in multiple resistance is mainly concentrated in two phage types common in returning travellers, For S. hadar, there has been a substan tial increase in the incidence of multiple resistance with over 50% of isolates now multiresistant, Substantial increases in the incidence o f resistance to ciprofloxacin in multiresistant S. typhimurium DT 104, S. virchow, and S. hadar since 1993, when the fluoroquinolone antibio tic enrofloxacin was licensed for veterinary use in the UK, are of par ticular concern.