Changes in the patterns and microbiology of spontaneous bacterial peritonitis : analysis of 200 cirrhotic patients.

Objective: The microbiological characteristics of spontaneous bacterial peritonitis (SBP) are changing worldwide with a shift in patterns of SBP and increasing prevalence of antibiotic-resistant bacteria. We, therefore, conducted this retrospective study aiming to characterise the current patterns and microbiology of SBP in our region.

Methods: We performed a retrospective chart review of patients presenting with their first episodes of SBP. The demographical, clinical and laboratory parameters of all patients at first paracentesis were recorded.

Results: The study included 200 cirrhotic patients with SBP. Mean age was 60.4±13.5 years and 116 (58%) patients were males. Liver cirrhosis was predominantly viral in 138 (69%) patients. Ascitic fluid cultures were positive in 103 (51.5%) patients and negative in 97 (48.5%). Ninety-eight (95.1%) patients had monomicrobial bacterial growth. The most common variants of spontaneous ascitic fluid infection were culture negative neutrocytic ascites (CNNA) in 97(48.5%) patients and SBP in 65 (32.5%) patients. E.Coli was most frequently isolated microorganism in 41 (39.8%) patients followed by staphylococcus species in 19 (18.4%) patients, Klebsiella pneumonae in 14(13.6%) patients and streptococcus species in 13 (10.7%) patients. The prevalence of extended spectrum beta-lactamases (ESBL) resistant E.Coli was 29.3%. Antibiotic resistance rate for meropenem, piperacillin\ tazobactam, ceftriaxone and ciprofloxacin was 0%, 22.0%, 29.0%, and 28.6% respectively.

Conclusions: Changes in the patterns and microbiology of SBP are evident in our region with increasing prevalence of culture negative SBP, extended spectrum beta-lactamases resistant E.Coli, and increased resistance rate to first line antibiotics. Our data argue for relying on periodic hospital based antibiotic susceptibility data whenever SBP is treated.