Introduction Spontaneous bacterial peritonitis (SBP) is a life threatening infection of ascitic fluid which occurs primarily in patients with pre-existing ascites in the setting of cirrhosis. Risk factors for developing SBP include: prior episode of SBP, gastrointestinal bleeding, ascitic total protein <1.0 g/dl and Child-Pugh score.1 Causative microorganisms include members of the normal microbial flora of the gastrointestinal tract including Escherichia coli (70%), Klebsiella species (10%), Proteus species (4%), Enterococcus faecalis (4%) and Pseudomonas species (2%).1 The choice of antimicrobial therapy must take into consideration the increasing frequency of hospital acquired infections, such as Clostridium difficile infection.

Aim To identify the local epidemiology and resistance patterns of culture-positive SBP.

Methods We retrospectively assessed the culture results of all ascitic fluid samples that grew a single organism in Leeds during the 3 years 2006–2008. Patients case notes were assessed to establish a diagnosis of SBP. An ascitic fluid neutrophil count ≥ 250/mm³ in patients with liver disease was used to confirm the diagnosis of SBP.1 ,2 We excluded culture-negative SBP.

Results Single organism positive ascitic cultures were identifed in 42 patients with liver disease and an ascitic fluid neutrophil count ≥250/mm³.

Mean age 52.1 years, 32/42 male. Underlying liver disease was ALD 35/42, HCV 3/42, PBC 1/42, NAFLD 1/42, Cryptogenic 1/42 and Post transplant 1/42.

At the time of diagnosis of SBP the mean ascitic total white cell count 5.25, mean ascitic neutrophil count 4.08, mean serum Na+ 129.6 mmol/l and mean serum creatinine 147 mmol/l. Overall Child score A 0, B 8/42, C 34/42 and mean MELD score 24.1.

The isolated organisms were Escherichia coli 15, Klebsiella spp. 7, other coliforms 10, Gram positive organisms 8 (including Enterococcus 2, Corynebacterium spp. 2).

The Gram-negative isolates were resistant to a number of antibiotics: ciprofloxacin 38% (13/34), cefuroxime 29% (10/34), amoxycillin 32% (11/34) and tazocin 17% (6/34).

The 30-day mortality was 50%.

Conclusion Empirical treatment regimes need to take into account local resistance patterns. Ciprofloxacin has been widely used for treatment and prophylaxis in SBP. Resistance has now become a significant problem.