Bacterial Translocation and Prognosis of Critically Ill Patients

ABSTRACT

PURPOSE: To identify Bacterial translocation (BT) from the gut to the blood in the critically ill patients by using the polymerase chain reaction (PCR) to confirm the sensitivity of PCR in the detection of intestinal bacterial deoxyribonucleic acid (DNA) in human blood. Further, to determine the relationship between the identification of BT and the prognosis of these patients. METHODS: The oligonucleotide primers used to amplify bacterial DNA from whole blood were the beta-galactosidase (BG) gene of E. coli, DNA coding for 16S ribosomal RNA (16S rRNA), and the glutamine synthase gene of Bacteroides fragilis (BFR). DNA was extracted from the blood of 45 cases of critically ill patients and 10 controls. PCR techniques were used to amplify the genes from E. coli, Bacteroides fragilis, and a region of 16S ribosomal RNA found in many gram-negative and positive bacteria. RESULTS: Bacterial DNA genes were not detected in any of the controls, but were found all in 6 cases of patients with positive blood cultures. Of the 39 cases with no growth in their blood culture, 11 cases in BG and BFR, and 13 cases in 16S rRNA had positive findings in bacterial DNA PCR. Fifteen cases (33%) in BG, 19 cases (42%) in BFR, and 16 cases (35.5%) in 16S rRNA of the critically ill patients had detectable bacterial DNA in their blood. Of those with a positive PCR, MOF developed in 11 cases (57.9%) and of these, 10 subsequently died of MOF. One case (3.8%) in the negative PCR was developed and died of MOF. Patients having positive translocated bacterial DNA had a worse prognosis than the group with a negative DNA. CONCLUSION: In order to confirm BT, the PCR method for detecting bacterial DNA in the blood of critically ill patients is more sensitive than blood cultures. BT from the gut can be a major factor in the development of multiple organ failures in critically ill patients. Therefore, early detection of BT with PCR can play a major role in the treatment of critically ill patients.