[Clinical and microbiological characteristics of spontaneous bacterial peritonitis (SBP) in a recent five year period].

Background/aims: Recently, treatment failure with the third generation of cephalosporin was increasingly noted in patients with spontaneous bacterial peritonitis (SBP). We therefore were to evaluate the pattern of antibiotic resistance and its clinical significance.

Methods: We retrospectively analyzed 580 episodes of SBP occurring between 1995 and 1999. There were 87 episodes of SBP in 1995, 222 in 1998, and 271 in 1999. The pattern of isolated organisms and antibiotic resistance, and prognostic factors for survival, were analyzed.

Results: Microorganisms were isolated in 41% of total episodes. The three most frequently isolated organisms were E. coli (48%), K. pneumoniae (15%), and Aeromonas (8%). The percentage of resistant strains to cefotaxime (9%, 14%, 32%) and ciprofloxacin (13%, 21%, 32%) significantly increased. The proportion of E. coli producing extended spectrum beta-lactamase (ESBL) also increased significantly (0%, 16%, 33%). The need of secondary antibiotics such as imipenem due to treatment failure was significantly increased from 0% in 1995 to 33% in 1999. Overall in-hospital mortality, however, was not changed (20%, 20%, 24%, respectively). The factor affecting early mortality was renal failure at diagnosis. Prognostic factors for long-term survival were the presence of associated malignancy and ESBL-producing microorganisms.

Conclusion: Microorgansims resistant to third generation cephalosporin and quinolone were increasingly isolated over the 5 years in patients with SBP. Measures to prevent in-hospital spread of resistant strains and indiscreet use of antibiotics should therefore be instituted.