Background/aims: Early detection and identification of bacteria in ascitic fluid could result in more timely treatment of cirrhotic patients with spontaneous bacterial peritonitis (SBP) or subclinical SBP. The aim of this study was to evaluate the usefulness of a bacterial DNA microarray for the rapid diagnosis of SBP and rapid bacterial identification in cirrhotic patients with ascites.

Methods: Thirty-seven cirrhotic patients with ascites (25 men and 12 women) participated. Ascitic fluid obtained from patients was tested by the bacterial DNA microarray method and by the conventional culture method.

Results: SBP and bacterascites were diagnosed in 8 (16.7%) of 48 specimens by the conventional method. The bacterial DNA microarray proved the existence of bacteria in 6 (75%) of 8 samples with SBP or bacterascites using the conventional method as a gold standard. A corresponding rate of bacterial species identification between the two methods was found in 5 of 6 samples (83.3%). It took 1.47+/-0.96 and 5.14+/-2.6 days to receive the data by the microarray and conventional method, respectively (p<0.0001). After antibiotic therapy, the cumulative survival rate of recovered cases (n=8) was higher than that of unrecovered cases (n=5) (p=0.0008).

Conclusion: Although the detection rate of the bacterial DNA microarray was similar to the conventional culture method, the DNA microarray could identify pathogens about 4 times more rapidly than bacterial cultivation, thus rendering it useful for managing cirrhotic patients with ascites.