Characterization of metronidazole resistant Helicobacter pylori

Ph.DDOCTOR OF PHILOSOPH

Metronidazole-Resistant Helicobacter pylori Is More Prevalent in Patients with Nonulcer Dyspepsia than in Peptic Ulcer Patients in a Multiethnic Asian Population

The trend of increasing prevalence of antibiotic resistance among Helicobacter pylori strains has been suggested as a cause of the failure of treatment of H. pylori infections. In this study, 120 of 211 antral biopsy specimens from patients with dyspeptic symptoms were found to harbor H. pylori. The isolates from the 120 specimens were tested by the agar dilution method, and 38 (31.7%) were found to be metronidazole resistant. Among the 211 subjects, 81 of 115 (70.4%) patients with peptic ulcer (PU) were infected with H. pylori, whereas 39 of 96 (40.6%) patients with nonulcer dyspepsia (NUD) were infected with H. pylori. Interestingly, significantly more NUD patients than PU patients harbored metronidazole-resistant H. pylori (22 of 39 [56.4%] and 16 of 81 [19.8%], respectively; P < 0.001). A similar pattern was also observed among NUD patients of different ethnicities but not between male and female patients (23 of 78 [29.5%] and 15 of 42 [35.7%], respectively; P = 0.54). In the posttreatment follow-up, five of six patients who had positive urea breath test results, indicating treatment failure, were NUD patients. Of these, four harbored metronidazole-resistant H. pylori strains. This further illustrates the relevance of metronidazole-resistant H. pylori in NUD patients. The significantly higher percentage of metronidazole-resistant H. pylori isolates in NUD patients may be attributed to the protection offered by the mucus layer of the nonulcerated stomach to the bacteria that reside below it, resulting in organism exposure to sublethal concentrations of metronidazole and leading to the induction of metronidazole resistance. The results demonstrate that the H. pylori isolates colonizing NUD patients are more likely to be resistant to metronidazole. It will therefore be useful to reevaluate the use of metronidazole in the treatment of NUD patients infected with H. pylori

Antiadhesive property of microalgal polysaccharide extract on the binding of Helicobacter pylori to gastric mucin

10.1111/j.1574-695X.2007.00248.xFEMS Immunology and Medical Microbiology502231-23

Performance of the HIV Blot 2.2, INNO-LIA HIV I/II Score, and Geenius HIV 1/2 Confirmatory Assay for use in HIV confirmation.

In view of recent revised recommendations for human immunodeficiency virus (HIV) confirmatory testing, the performance of 3 HIV confirmatory assays was compared. Using the HIV Blot 2.2 (MP-WB), the INNO-LIA HIV I/II Score (INNO), and the Geenius HIV 1/2 Confirmatory Assay (Geenius), we tested 199 HIV-1 positive, 161 HIV negative, 65 HIV western blot indeterminate, 26 HIV seroconversion, 34 early HIV infection and 4 HIV-2 positive archived specimens. We show that all 3 assays had comparable test sensitivity in the detection of HIV-1 positive cases. However, less non-specific reactivity was observed with the INNO and Geenius assays, where both of them were able to resolve MP-WB indeterminate cases. When early HIV cases were considered, INNO and Geenius were more likely to confirm an early-stage infection as positive. Nevertheless, overall poor sensitivity (25.5% - 44.7%) of these assays for the detection of early cases was observed, likely because these cases had very low or non-detectable levels of HIV antibodies. Hence, further testing by a nucleic acid test or a p24 antigen test of specimens reactive on screening with a fourth generation Ag/Ab assay that are negative on confirmatory testing for HIV-specific antibody, may be useful. In conclusion, INNO and Geenius had comparable test performance, although the ease of use and shorter assay time for Geenius may make it the preferred choice for laboratories. In that regard, of note is our observation of non-specific reactivity of lipaemic specimens to the HIV-2 gp140 band in the Geenius assay, which should prompt caution when interpreting results of such specimens

Breakdown of results for early HIV cases.

<p>Breakdown of results for early HIV cases.</p

Test results using the MP Biomedicals HIV Blot 2.2 assay, Fujirebio INNO-LIA HIV I/II Score, and Bio-Rad Geenius HIV 1/2 Confirmatory Assay¹.

<p>Test results using the MP Biomedicals HIV Blot 2.2 assay, Fujirebio INNO-LIA HIV I/II Score, and Bio-Rad Geenius HIV 1/2 Confirmatory Assay<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0199502#t002fn001" target="_blank">¹</a>.</p

Performance of the Fujirebio INNO-LIA HIV I/II Score and Bio-Rad Geenius HIV 1/2 Confirmatory Assay.

<p>Performance of the Fujirebio INNO-LIA HIV I/II Score and Bio-Rad Geenius HIV 1/2 Confirmatory Assay.</p

List of specimens used.

<p>List of specimens used.</p