Clinical value of multiplex PCR in the diagnosis of secondary infection of severe acute pancreatitis

Abstract

Objective To investigate the diagnostic value of multiplex polymerase chain reaction (m- PCR) for diagnosing second infection of severe acute pancreatitis (SAP), and to provide evidence for anti-infection treatment of SAP. Methods From January 2011 to December 2014, thirty five patients of SAP were enrolled. Seven to fourteen days after SAP onset, patients' blood samples were taken and the presence of infection was determined by m-PCR. In the meantime, peripheral blood or the paracentesis fluid was cultured, and the result of culture was regard as golden standard to diagnose infection. Results The m-PCR could simultaneously detect 9 kinds of intestinal resident pathogenic bacteria, and the lower limit of detection was 10~1 000 copies. The detection rates were as follows (cultivation vs. m-PCR): staphylococcus aureus 6 vs 5 cases, staphylococcus epidermidis 11 vs 9 cases, enterococcus faecalis 2 vs 3 cases, enterococcus faecium 6 vs 7 cases, escherichia coli 19 vs 17 cases, klebsiella pneumoniae 2 vs 3 cases, pseudomonas aeruginosa 6 vs 4 cases, acinetobacter baumannii 2 vs 2 cases, malt narrow food aeromonas 4 vs 2 cases. The 7th~14th days after SAP onset, the blood or paracentesis fluid culture was positive in 27 patients, and negative in 8 cases. And the m-PCR results were positive in 30 patients, and negative in 8 cases. The m-PCR results were positive in 30 patients, negative in 5 patients. The m-PCR results were positive in 3 patients who had negative culture results. In the remaining 32 cases, the results were consistent between the two detection methods. When the culture result was regarded as golden standard, the sensitivity, specificity and accuracy of m-PCR were 100%, 62.5% and 91.43%, respectively. The positive predictive value and the negative predictive value were 90% and 100%, respectively. It took (26±15) hours on average to obtain the result of culture method, and it took (102±32) hours on average to obtain the confirmative results. It took (12±8) hours on average to obtain the result of the m-PCR method. The time course of m-PCR was significantly shorter than that of the traditional culture method, and the difference was statistically significant (P<0.05). Conclusions The m-PCR method can be used to monitor the bacterial infection in patients with SAP. The m-PCR method is a highly sensitive and rapid detection approach, which is worth of clinical application. Key words: Pancreatitis, acute necrotizing; Polymerase chain reaction; Secondary infection