Role of Real Time Polymerase Chain Reaction in Diagnosis of Spontaneous Bacterial Peritonitis

Background: Spontaneous bacterial peritonitis (SBP) is a severe and possibly life-threatening consequence in patients with liver cirrhosis and ascites. Standard diagnostic tools such as ascitic fluid culture often suffer from low sensitivity with delayed results. Real-time polymerase chain reaction (RT-PCR) as a more rapid and sensitive molecular diagnostic technique has been developed to identify bacterial DNA in ascitic fluid. Objective: To evaluate the role of real-time PCR in the diagnosis of spontaneous bacterial peritonitis, compared to ascitic fluid vial culture. Methodology: This research was designed as a diagnostic cross-sectional study. Spontaneous bacterial peritonitis was identified using both blood culture bottles and real-time PCR techniques. The study population included 68 male and 32 female patients aged between 45 and 60 years, all in different stages of hepatic cirrhosis with ascites (mild, moderate, and severe), and exhibiting acceptable hematological and biochemical parameters. Results: Real-time PCR targeting 16s rRNA demonstrated much higher sensitivity, detecting bacterial DNA in 85% of patients, including many who had negative culture results. There was a statistically significant difference between PCR positive and negative patients regarding WBC count, AST, CRP, ascitic fluid albumin, and SAAG levels, while a significant difference was also observed between culture positive and negative patients regarding ascitic fluid total leukocytic count and neutrophil count (P-value <0.05). Conclusion: PCR testing of ascitic fluid using 16s rRNA is a more sensitive and accurate diagnostic tool compared to conventional culture. While culture detected bacterial growth in just over half of the patients, PCR was able to identify bacterial DNA in the majority of cases, including those with negative culture results.