The emergence of bacterial resistance in hospitals--a need for continuous surveillance

The antibiotic sensitivities of a total of 220,000 isolates from 44 hospitals collected over 2.5 years were monitored by computer. Gram-negative organisms account for 63% of the total, the most common being Escherichia coli (43%). Staphylococcus aureus was the most frequently isolated Gram-positive organism (44%). The organism most commonly isolated from blood was E. coli; this organism was susceptible to ceftazidime (100%), ampicillin (47%), gentamicin (99%) and co-trimoxazole (85%). The organism most frequently isolated from sputum was Haemophilus influenzae; this organism was susceptible to ceftazidime (99%), cefuroxime (99%), ampicillin (89%) and erythromycin (78%). A 15-fold increase in the use of ceftazidime over the past 4 years has not been accompanied by increased resistance in common pathogens. Analysis shows that the susceptibility of E. coli and Pseudomonas aeruginosa to ceftazidime has remained constant throughout the duration of this survey. The data collected from this type of survey can be used to determine local trends in antibiotic susceptibility and hence aid the rational use of antibiotics in hospitals.