Molecular Biomarkers & Diagnosis

The Role of 16s Ribosomal RNA in Diagnosing Spontaneous Bacterial Peritonitis

Abstract

Sally Abed, Mohamed Egezy, Tarek sheta and Maysaa El-Sayed Zaki

Background: Cancer, the accurate clinical diagnosis of spontaneous bacterial peritonitis (SBP) is challenging due to frequent absence of the symptoms and signs which are non-specific. The laboratory diagnosis of SBP depends mainly on the ascetic fluid neutrophil count. Therefore, it is recommended to inoculate the ascitic fluid into blood culture but cultures are time consuming and have a limited value to urgently direct the initiation of specific effective antibiotic treatment.
Aim of study: To evaluate the role of 16s ribosomal RNA in early diagnosis of SBP.
Patients and methods: The present study was cross-sectional study that was carried out in Mansoura University hospital from January 2016 till March 2017. The study included 120 patients complaining of chronic hepatitis C. Each patient was subjected to full clinical history including symptoms of spontaneous bacterial peritonitis such as fever, constipation and abdominal pain. The severity of liver affection was classified according to Child score. Complete liver function tests were performed. The peritoneal fluid was divided to three samples, one sample for total leucocytic count by hemocytometer, the other sample was centrifuged and the sediment was cultured on blood agar, MacConkey agar and Sabouraud’s dextrose agar at 37C for 24-48 hours DNA Extraction the sediment pellet of the peritoneal fluid was subjected to DNA extraction by QIAampDNAM; ini kit (QIAGEN, Germany) according to the manufacturer’s instruction.
Results: The culture positive cases were 21 patients 20 of them were positive for 16sRNA and only 1 patient was negative for 16sRNA. While 16s RNA was positive in 26 patients in which 6 were negative culture. The WBCS count was >250/mm3 in 31 patients of which 26 patients were positive for 16s RNA and 21 were culture positive. The 16sRNA had higher sensitivity (81.25%), while the culture the sensitivity was (67.7%).
Conclusion: In the current study, we assessed the 16s ribosomal RNA detection by PCR and it was more rapid and sensitive than bacterial cultures to confirm bacterial infection of the ascetic fluid even after cultures with bedside inoculation of the ascetic fluid samples.