Background: Neonatal septicemia is a serious life-threatening infectious disease. Early diagnosis will improve the effectiveness of intervention, prognosis, and will reduce complications. This study was undertaken to explore the value of 16S rRNA oligonucleotide microarray in the early diagnosis of neonatal septicemia.

Methods: Primers and oligonucleotide probe against the 16S rRNA gene were designed, then the probe was fixed on a specially designed glass slide to make a microarray. Venous blood was drawn from 285 neonates who were suspected of bacterial infection for blood culture and gene analysis of bacterial 16S rRNA, respectively. The DNA extracted from blood sample and cerebrospinal fluid was amplified by PCR, and the positive products were applied to the microarray for hybridization. Finally, the chip was scanned with laser, and the results were analyzed.

Results: The positive rate of PCR detection was 5.96% (17/285), significantly higher than that of blood culture (2.81%, 8/285) (P<0.01). In contrast to the confirmed diagnosis of septicemia in these patients, the sensitivity, specificity and correct diagnosis index of PCR were 100%, 96.75%, and 0.968, respectively. Microarray hybridization was carried out for the 17 samples of PCR-positive reaction. Positive results were detected in all samples by universal probes: G+ probe in 12 samples, and G- probe in 5 samples. In the 8 samples with positive results shown by PCR and blood culture, the results of microarray hybridization were consistent with those of blood culture in detecting bacterial species.

Conclusions: Microarray technique can be used to rapidly diagnose neonatal septicemia by specially detecting the 16S rRNA gene in clinical samples. The sensitivity and specificity of this technique are much higher than those of blood culture, PCR, and other methods. It also can quickly identify the pathogen of the disease.