A novel diagnostic tool for detecting neonatal infections using multiplex polymerase chain reaction.

BACKGROUND: In newborns with infections, it is necessary to detect various pathogens rapidly and accurately, because the infections are often fatal when diagnosis is delayed. However, no diagnostic tools that rapidly detect pathogens causing neonatal infectious diseases are available.

OBJECTIVES: To establish a rapid diagnostic tool using multiplex polymerase chain reaction (PCR) to detect 8 major pathogens that often cause neonatal infections, including Group B Streptococcus, Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, Ureaplasma urealyticum, herpes simplex virus, Cytomegalovirus, and Candida albicans, and to validate this tool in the neonatal intensive care unit (NICU).

METHODS: One hundred and thirty clinical samples were obtained from newborns with any infectious signs or histories. DNA was extracted from these samples and multiplex PCR was performed with a mixture of 8 primer pairs, all designed to amplify pathogenic DNA and produce different sizes of amplicons. Seventy-seven samples with suspicion of bacterial infections were also examined by bacterial culture to evaluate the accuracy of the multiplex PCR results.

RESULTS: Six of the 8 pathogens could be rapidly detected by our multiplex PCR method, within 3.5-4.5 h. These positive results led us to immediately diagnose and select proper drugs against each pathogen. In comparison with culture results, our test characteristics were as follows: specificity: 93%, negative predictive value: 96%, and concordance rate: 90%.

CONCLUSIONS: We have established and validated a rapid diagnostic tool for detecting pathogens using multiplex PCR, which may be useful for the confirmed diagnosis of neonatal infections in the NICU.