An assessment by in situ hybridization method for pathogens of severe respiratory infection

Abstract

It has been shown that the in situ hybridization(ISH)method for the detection of phagocyted bacteria in polymorphonuclear neutrophils is more sensitive than conventional blood culture in patients with sepsis.The present study was designed to further evaluate the clinical utility of the ISH method,using a commercially available kit (Hybrizep ),for detecting pathogens in patients with severe respiratory infections.Peripheral blood was taken from patients with severe respiratory infections for both routine blood culture and the ISH method,respectively.In addition,focal samples including sputum,bronchoalveolar lavage,central and thoracic catheter, etc. were simultaneously examined for bacterial culture. A total number of 22 specimens was examined.The positive cases by ISH were 50.0% in the respiratory infections,which were significantly higher than those in blood cultures (9.1%).However,identical pathogens in the ISH method were not isolated from blood and/or other sources in respiratory sites. These findings suggest a possibility of high frequency of bacteremia or multifactorious pathogens in severe respiratory infections.The ISH method may provide additional information on serious respiratory infections for the detection of bacteremia.However, the clinical utility by the ISH method for patients with severe respiratory infection remains undetermined.Shinshu Med J 59 : 223―228, 2011 (Received for publication March 1,2011;accepted in revised form April 7,2011)