253: Assessment of adenovirus subgenera prevalence by real-time PCR in immunocompromised patients (2007)

Background: Adenoviruses (Adv) are double-stranded DNA viruses that can be classified by serotypes (1-51), which are grouped into six subgenera (A-F). Within the different subgenera, viral characteristics vary in terms of host range, disease type, and genetic composition. Real-time PCR has proven to be a rapid, sensitive, and specific way to analyze the variable regions of the Adv genome for subgenera determination. Using this methodology, we determined the prevalence of Adv subgenera in a variety of Adv-positive clinical specimens collected from immunocompromised patients.Methods: Initially we utilized real time PCR TaqMan® chemistry to quantify AdV DNA in clinical specimens using a single pair of primers and a minor groove-binding probe (MGB) designed to detect and quantitate all 51 Adv serotypes. From specimens that were determined to be Adv-positive with this assay, we randomly selected twenty-eight plasma, twenty-one urine, and three fecal/rectal samples for Adv subgenera classification. Each specimen was analyzed by six individual TaqMan® assays (Watzinger et al., J. Clin. Microbiol 42:5189), each designed to specifically detect all known serotypes within each of the six subgenera.Results: Plasma specimens tested with the pan-AdV assay had viral loads ranging from 7.34×101 – 5.73×106 copies/ml. Urine specimens had viral loads ranging from 1.24×102 – 1.57×107 copies/ml, and fecal/rectal samples had viral loads ranging from 9.04×103 – 1.02.x107 0×107 copies/ml. Subgenera determination for plasma demonstrated that 21% (6 samples) were Subgenus B, and 79% (22 samples) were Subgenus C. Results from urine demonstrated that 81% (17 samples) were Subgenus B, 14% (3 samples) were Subgenus C, and 5% (1 sample) was Subgenus D. Of the three fecal/rectal samples two were Subgenus D and one was Subgenus F. Using Fisher’s Exact Test, the subgenera distribution among plasma and urine was determined to be significantly different (P<0.0001; odds ratio=20.78, 95% CI: 4.526 to 95.38).Conclusion: Results of this study demonstrate that the prevalence of AdV subgenera differ significantly among specimen types collected from immunocompromised patients. The predominant subgenus identified in urine was B while the predominant subgenus identified in plasma was C. These results support previous findings for prevalence in plasma and urine. Real-time PCR technology provides an efficient means to accurately diagnose Adenovirus infections and identification of AdV subgenera. Background: Adenoviruses (Adv) are double-stranded DNA viruses that can be classified by serotypes (1-51), which are grouped into six subgenera (A-F). Within the different subgenera, viral characteristics vary in terms of host range, disease type, and genetic composition. Real-time PCR has proven to be a rapid, sensitive, and specific way to analyze the variable regions of the Adv genome for subgenera determination. Using this methodology, we determined the prevalence of Adv subgenera in a variety of Adv-positive clinical specimens collected from immunocompromised patients. Methods: Initially we utilized real time PCR TaqMan® chemistry to quantify AdV DNA in clinical specimens using a single pair of primers and a minor groove-binding probe (MGB) designed to detect and quantitate all 51 Adv serotypes. From specimens that were determined to be Adv-positive with this assay, we randomly selected twenty-eight plasma, twenty-one urine, and three fecal/rectal samples for Adv subgenera classification. Each specimen was analyzed by six individual TaqMan® assays (Watzinger et al., J. Clin. Microbiol 42:5189), each designed to specifically detect all known serotypes within each of the six subgenera. Results: Plasma specimens tested with the pan-AdV assay had viral loads ranging from 7.34×101 – 5.73×106 copies/ml. Urine specimens had viral loads ranging from 1.24×102 – 1.57×107 copies/ml, and fecal/rectal samples had viral loads ranging from 9.04×103 – 1.02.x107 0×107 copies/ml. Subgenera determination for plasma demonstrated that 21% (6 samples) were Subgenus B, and 79% (22 samples) were Subgenus C. Results from urine demonstrated that 81% (17 samples) were Subgenus B, 14% (3 samples) were Subgenus C, and 5% (1 sample) was Subgenus D. Of the three fecal/rectal samples two were Subgenus D and one was Subgenus F. Using Fisher’s Exact Test, the subgenera distribution among plasma and urine was determined to be significantly different (P<0.0001; odds ratio=20.78, 95% CI: 4.526 to 95.38). Conclusion: Results of this study demonstrate that the prevalence of AdV subgenera differ significantly among specimen types collected from immunocompromised patients. The predominant subgenus identified in urine was B while the predominant subgenus identified in plasma was C. These results support previous findings for prevalence in plasma and urine. Real-time PCR technology provides an efficient means to accurately diagnose Adenovirus infections and identification of AdV subgenera.