CHANGES IN NATURE AND ANTIBIOTIC-RESISTANCE OF BACTERIA CAUSING PERITONITIS IN CIRRHOTIC-PATIENTS OVER A 20 YEAR PERIOD

Aim-To assess all clinically and bacteriologically documented episodes of spontaneous bacterial peritonitis diagnosed in a single unit over a 20 year period, to identify changes in the nature and antibiotic res istance of the causative bacteria. Setting-A specialist liver disease unit in a tertiary care centre. Material-Cultured ascitic fluid obtain ed in the course of 240 consecutive episodes of clinically and bacteri ologically proven spontaneous bacterial peritonitis. Patient recruitme nt remained stable during the 20 year period in terms of the number of cirrhotic patients admitted and the severity of their condition. Resu lts-78.7% of isolates were Enterobacteriaceae (Escherichia coli in 51% ) and 19% were Gram positive cocci. Until 1979 all the Enterobacteriac eae had the wild phenotype, compared with only 50% at the end of the s tudy period. Since 1993, 22% of Enterobacteriaceae have been resistant to third generation cephalosporins. Methicillin resistant staphylococ ci were only isolated after 1989. Conclusions-Changes in the epidemiol ogy and antibiotic resistance of bacteria causing spontaneous bacteria l peritonitis must be monitored for optimal treatment.