Tropheryma whippelii DNA is rare in the intestinal mucosa of patients without other evidence of Whipple disease.

Background: Little is known about the pathogenesis of Whipple disease, the reservoirs of Tropheryma whippelii, and the proportion of persons harboring the bacterium without "classic" intestinal abnormalities.

Objective: To assess the presence of T. whippelii in patients undergoing upper endoscopy for a variety of indications.

Diagnosis of herpes simplex virus infections in the clinical laboratory by LightCycler PCR.

Herpes simplex virus (HSV) causes several clinical manifestations in both normal and immunocompromised hosts; this agent is the most frequently detected virus in diagnostic laboratories. Recovery of the virus in cell culture is considered the "gold standard" for detection of this virus from sources other than cerebrospinal fluid. LightCycler is a newly developed, commercially available system designed to rapidly perform PCR, with real-time detection of PCR products by a fluorescence resonance energy transfer assay.

Determination of hepatitis C virus genotype by direct sequence analysis of products generated with the Amplicor HCV test.

Consistent with other members of the family Flaviviridae, hepatitis C virus (HCV) demonstrates a high degree of sequence variation throughout the coding regions of its genome. However, there is a high degree of sequence conservation found within the 5' untranslated region (UTR) of the genome, making this region a target of choice for most nucleic acid amplification-based detection assays. In this study, the Amplicor HCV test, a commercially available assay which detects the 5'UTR, was used for the detection of HCV RNA in 669 serum samples obtained from a cohort of liver transplantation patients.

Comparison of agar dilution, broth dilution, disk diffusion, and the E-test for susceptibility testing of penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae.

An evaluation to determine the optimal methods for the in vitro susceptibility testing of 41 clinical isolates and the ATCC 49619 strain of Streptococcus pneumoniae to penicillin was undertaken. No very major or major interpretive errors were observed with the following test methods and media: agar dilution using either Mueller-Hinton medium with lysed horse blood or Haemophilus test medium; broth dilution using cation-adjusted Mueller-Hinton medium with lysed horse blood, Haemophilus test medium, or Todd-Hewitt medium; and the epsilo-meter test (E-test) using agar containing Mueller-Hinton medium and 5% sheep blood. The disk diffusion method using agar containing Mueller-Hinton medium and 5% sheep blood agar was an effective screening method, requiring confirmation by a dilution susceptibility test method.

Indeterminate results of the second-generation hepatitis C virus (HCV) recombinant immunoblot assay: significance of high-level c22-3 reactivity and influence of HCV genotypes.

A second-generation recombinant immunoblot assay (RIBA 2.0) is used in the United States to confirm infection with hepatitis C virus (HCV) in samples that are anti-HCV (enzyme immunoassay) positive. In some cases, indeterminate results of RIBA 2.