Genetic Profiling of Enterohemorrhagic Escherichia coli Strains in Relation to Clonality and Clinical Signs of Infection

Abstract

The new generation assay Versant HCV RNA 3.0v (Bayer Diagnostics) was evaluated to quantify hepatitis C virus (HCV) RNA levels in liver biopsy specimens from patients with HCV and human immunodeficiency virus (HIV) coinfection. A total of 25 liver biopsies and sera collected at the time of liver biopsy were used. The efficiency of HCV RNA recovery from spiked samples was between 38.6 and 50.7%, and reproducible measurements of viral load were observed (the intra- and interrun coefficients of variation were 0.5 to 13% and 3.5 to 24.7%, respectively), with good specificity and sensitivity. Linearity was evaluated in the range of 96,154 to 769 IU/μg by using a serially diluted high-titer sample. Coinfected patients had high HCV RNA viral loads in serum and liver (498,471 IU/ml and 231,495 IU/μg, respectively), and both levels were correlated (r = 0.63; P < 0.01). The amount of hepatic HCV RNA was significantly higher among patients with genotype 1 than among patients with genotype 3 (P < 0.01). The virological end-of-treatment response in the serum was associated with a lower pretreatment intrahepatic HCV viral load (P = 0.03). The new version of b-DNA is a sensitive, specific, and reproducible method for quantitating HCV RNA in the liver. Given its positive analytical performance, the assay will be used to evaluate the HCV RNA levels in the serum and liver during follow-up of patients treated with an anti-HCV therapeutic regimen.