Universal primer V3 coupled with multiplex PCR for the pathogen detection of infective endocarditis

Abstract

Objective To investigate the pathogen of 21 infective endocarditis (IE) cases treated with operation in Shanghai Children's Medical Center from 2007 to 2010.Methods Blood culture,vegetation culture and vegetation PCR assay(target gene to the conserved region V3 in 16SrRNA gene) were detected in 21 IE patients; multiplex PCR amplification of staphylococci for methicillin-resistant staphylococcus was performed.Results Of 21 IE cases,20 cases were detected positive by vegetation PCR with the detection rate of 95.2％,12 IE cases were detected positive by blood culture with the detection rate of 57.1％,2 IE cases were detected positive by vegetation culture with the detection rate of 9.5％.The difference of the positive rates of the three methods was statistically significant (P ＜ 0.0001).The vegetation PCR of one case was actinobacillus actinomycetemcomitans,while the blood culture was haemolysis pasteurell which was inconsistent with the vegetation PCR result.Howerver,the PCR result of colony obtained by blood culture was consistent with vegetation PCR that was confirmed as actinobacillus actinomycetemcomitans.The endocardium PCR results of 11 IE cases were consistent with the results of blood culture.MecA gene was detected by multiplex PCR,which could identify methicillin-resistant staphylococcus quickly,sensitively and accurately and could also effectively identify methicillin resistant staphylococcus aureus,when coupled with femA gene detection,thus glycopeptides antibiotic could be prescribed promptly.All the 21 patients recovered and discharged without infection recurrence in the follow-up.Conclusion Universal primer V3 coupled with multiplex PCR can improve vegetation pathogen detection rate of IE patients and is minimally influenced by antibiotic therapy.Multiplex PCR can be applied for etiological diagnosis of IE patients with indication of surgery and negative blood culture or difficult diagnosis,contributing to post-surgery antibiotics selection and improvement of recovery rate of IE patients. Key words: Infective endocarditis; Etiology ; Diagnosis ; Polymerase chain reaction; 16SrRNA