A comparison of antimicrobial resistance rates in Gram-positive pathogens isolated in the UK from October 1996 to January 1997 and October 1997 to January 1998.

Rates of resistance for two consecutive years for 28 centres (10 Teaching, nine Associate Teaching and nine District General hospitals) in the UK were compared. Combined rates of resistance for each of the hospital types of Staphylococcus aureus to methicillin revealed an increase in the rate of resistance in Teaching hospitals (12.5% year 1, 23.5% year 2), but, for Associate Teaching and District General hospitals rates fell (Associate Teaching 19.1% year 1, 11.9% year 2; District General 16.5% year 1 and 11.3% year 2). Using conventional methodology to determine MICs, no strain was considered to have reduced susceptibility to vancomycin. Among coagulase-negative staphylococci, increased resistance was observed for Staphylococcus epidermidis to rifampicin, for Staphylococcus haemolyticus to clindamycin, for Staphylococcus saprophyticus to penicillin and for Staphylococcus spp. to clindamycin, methicillin and rifampicin. For Streptococcus pneumoniae an upward trend in low-level resistance to penicillin was observed (18 of the 28 centres), however, for high-level resistance the trend was in the opposite direction (only four centres showed an increase). For Enterococcus faecalis there was a trend to a fall in levels of resistance, the only exception being an increase in high-level gentamicin resistance (10.5% year 1, 15.1% year 2, P = 0.0388). For Enterococcus faecium rates of resistance were not significantly different except for increases in resistance to nitrofurantoin and rifampicin.