Frequency of occurrence of Campylobacter pylori and analysis of the systemic and local immune response

Evaluation of a commercial latex test for serological diagnosis of Helicobacter pylori infection in treated and untreated patients

The value of a commercially available latex test (Pyloriset) for the diagnosis of Helicobacter pylori infection by demonstration of specific antibodies was compared with that of direct diagnostic methods such as culture, biopsy-urease test and microscopy of fuchsin-stained smears. The sera were from 136 patients who prior to this study either had or had not been treated for Helicobacter pylori-infection simultaneously with amoxicillin (3 x 750 mg/day) and metronidazole (3 x 500 mg/day) for 12 days. On average, the sensitivity of the test was 90%. The specificity with sera from untreated patients was 75.9%; with sera from treated patients specificity was 22.2%, 28% and 20% 1, 3 and 6 months respectively after start of treatment. Only as late as one year after the onset of chemotherapy did the specificity return to 67%. Because of its low specificity this test does not offer any advantage over other tests in the detection of Helicobacter pylori-infection or in monitoring the chemotherapeutic success.

Strain variation in Campylobacter pylori detected by numerical analysis of one-dimensional electrophoretic protein patterns

A total of 21 clinical isolates of Campylobacter pylori from Peru and the United Kingdom and two reference strains (from Australia), including the type strain (NCTC 11637T), were characterized by high resolution one-dimensional SDS-polyacrylamide gel electrophoresis of cellular proteins. The protein patterns contained more than 40 discrete bands and the approximate molecular weights of the major bands were 22, 27, 46, 57, 60, 65 and 93 kD. The total patterns were used as the basis of numerical analysis. Most strains were clustered in four phenons at 91% similarity with the exception of six ungrouped strains. Overall similarity was high with all strains linked in the phenogram at greater than or equal to 81%. Variation among strains was attributable principally to qualitative and quantitative band differences in the 47 to 56 kD (hypervariable) region of the C. pylori protein profile. From the analysis, ten different electropherotypes (EP-types) were identified. We demonstrated that differences were detectable among isolates from widely separated geographical locations as well as from the same location, although multiple isolates from two Peruvian patients had the same electropherotype. Our results indicate that determination of protein profiles provides the basis of a reproducible method for characterization of C. pylori isolates.

Comparison of different antigen preparations in an evaluation of the immune response to Campylobacter pylori

This study presents a novel approach to the analysis of protein antigens of Campylobacter pylori for use in serology. Protein fractions of this bacterium were resolved in polyacrylamide gel electrophoresis, eluted from gel strips in an electric field and used for coating of microtiter plates in an ELISA-type assay run with a small set of sera from both infected and non-infected patients. Reactivity and discriminative power of the different fractionated antigens (1-9) and crude antigen preparations (A-C) were compared. Better discrimination was achieved between positive and negative sera with high molecular weight fractionated preparations (antigens 8 and 9) than with low molecular weight fractions. Among the crude antigen preparations, antigens A (sonicated whole cells) and C (ultracentrifugated sonicate) seem to have a better discriminative power than antigen B (acid glycin extract).