• Spontaneous bacterial peritonitis (SBP) refers to ascitic fluid infection with no recognizable source and occurs commonly in patients with cirrhosis.
• Diagnosis of spontaneous bacterial peritonitis requires an ascitic fluid absolute polymorphonuclear leukocyte (PMN) count > 250 cells/mm3 and a positive ascitic fluid bacterial culture without an intra-abdominal surgically treatable source of infection. Culture-negative neutrocytic ascites refers to patients who have a PMN count of at least 250 cells / mm3 but with a negative bacterial culture in the absence of pancreatitis or recent receipt of antimicrobial therapy.
• Prior to administering antibiotics, ascitic fluid (at least 10 ml) should be obtained and then directly inoculated into a blood culture bottle at the bedside, instead of sending the fluid to the laboratory in a syringe or container. The practice of immediate inoculation in blood culture bottles improves the yield on bacterial culture from approximately 65 to 90%.  Separate and simultaneous blood cultures should also be obtained, as up to 50% of patients with SBP have concomitant bacteremia.
• It is important to distinguish SBP from secondary bacterial peritonitis because of the critical need to determine whether surgical intervention is needed.
• Patients with risk factors such as ascitic fluid protein concentration less than 1g/dl, variceal bleed or a history of SBP have benefited from prophylaxis with trimethroprim-sulfamethoxazole (one double strength tablet once daily), ciprofloxacin (500 mg b.i.d) or norfloxacin (400 mg o.d) in the western literature. However these antibiotics are unlikely to be useful for prophylaxis in India as the prevalence of resistance is >20% even for community acquired isolates, and may drive further resistance.

Antibiotics regimen for SBP