Specific detection and typing of adenovirus types 40 and 41 in stool specimens by dot-blot hybridization

Abstract

A dot-blot hybridization test was developed which allowed the direct detection of fastidious enteric adenovirus DNA in stool specimens from children with diarrhea and simultaneous typing of the viruses as adenovirus type 40 (Ad40) or Ad41. Cloned PstI fragments of Ad40 and Ad41 were used as 32P-labeled probes in the test, which allowed detection of picogram quantities of viral DNA in 20 to 40 microliter of stool suspension. Results were obtained within 48 h. The type specificity of the test was evaluated with 76 specimens known to contain either Ad40 or Ad41 by restriction enzyme analysis. Sixty-one specimens had sufficient DNA to be detected without any removal of protein. Thirty-one adenoviruses were typed as Ad40, and 30 were typed as Ad41, giving 100% correlation with the results of restriction enzyme analysis. The other 15 specimens were detected and typed as Ad40 or Ad41 only after removal of protein by a phenol extraction method. The dot-blot hybridization method is particularly useful for identifying those Ad40 and Ad41 strains which defy all attempts at culture and will be a useful tool in the epidemiology of fastidious enteric adenovirus infections.