An eight-year survey of the antimicrobial susceptibility patterns of 85,971 bacteria isolated from patients in a district general hospital and the local community.

Antimicrobial susceptibilities were determined for 85,971 bacteria isolated from clinical specimens in the microbiology department of a single district general hospital during the eight-year period between 1984 and 1991. The isolates included 45,786 coliforms, 4483 Proteus spp. and 2644 Pseudomonas spp. from urine and 13,324 Staphylococcus aureus, 7311 beta-haemolytic streptococci, 4741 coliforms, 3643 Pseudomonas spp., 2778 Haemophilus influenzae, 638 Proteus spp. and 623 Streptococcus pneumoniae from other sites (excluding blood). Patterns of susceptibility remained largely unchanged during the study period, except for a decline in the susceptibility of Proteus spp. to trimethoprim between 1984 and 1988 which had reversed itself by 1990 and a reduction in the susceptibilities of Pseudomonas spp. and S. aureus to ciprofloxacin between 1986 and 1991. The susceptibilities of coliforms which had been isolated from sites other than the urinary tract to ampicillin, cefazolin and cefuroxime decreased between 1984 and 1988 but a more variable pattern was noted in subsequent years. Susceptibility of S. aureus to penicillin fell during the first five years of the study but has remained stable since. No change was observed in the susceptibility pattern of H. influenzae. In our experience, gentimicin-resistant Gram-negative bacilli, methicillin-resistant S. aureus and penicillin-resistant S. pneumoniae were rarely isolated.