Ay-Huey Huang

Quadruple therapy containing amoxicillin and tetracycline is an effective regimen to rescue failed triple therapy by overcoming the antimicrobial resistance of Helicobacter pylori

Aim : To identify optimal antibiotics for second‐line quadruple therapy of Helicobacter pylori after failed 1‐week triple therapy.

Vitamin C and E Supplements to Lansoprazole‐Amoxicillin‐Metronidazole Triple Therapy May Reduce the Eradication Rate of Metronidazole‐Susceptible Helicobacter pylori Infection

Aim. To test whether vitamin C and E supplements to triple therapy can improve the Helicobacter pylori eradication rate and gastric inflammation.

High Rates of Antimicrobial Resistance among Clinical Isolates of Nontyphoidal Salmonella in Taiwan

Abstract To assess trends in antimicrobial-resistant Salmonella infections from 1989 to 1996 in southern Taiwan, the minimum inhibitory concentrations (MICs) of 14 antibiotics or antibiotic combinations were determined by the agar dilution method for 297 clinical isolates of nontyphoidal Salmonella. The rates of resistance to ampicillin, chloramphenicol, and tetracycline were 65, 67, and 78%, respectively. Resistance to trimethoprim-sulfamethoxazole (TMP-SMX) increased from 25% in 1989–1992 to 35% in 1993–1996 (P=0.057). For new quinolones and extended-spectrum cephalosporins, no resistant strains were encountered. Multiple resistance to more than five antimicrobial drugs doubled from 10.6% in 1989–1992 to 19.7% in 1993–1996. Multiply resistant salmonellae were isolated more commonly from blood samples than from feces (30% vs. 14%, P<0.05). In Taiwan, ampicillin, chloramphenicol, and even TMP-SMX are no longer the drugs of choice for treatment of serious nontyphoidal Salmonella infections. Extended-spectrum cephalosporins are now the preferred drugs in Taiwan for treatment of invasive Salmonella infections in children.

The rdxA Gene Plays A More Major Role Than frxA Gene Mutation in High‐level Metronidazole Resistance of Helicobacter pylori in Taiwan

Background.  Metronidazole‐resistant H. pylori associating with mutations of rdxA or frxA is still a debated topic. This study investigates whether rdxA and frxA mutations of H. pylori accounted for the high MIC value (≥ 64 µg/ml) of metronidazole (Mtz).

Development of Helicobacter pylori infection model in BALB/c mice with domestic cagA-positive and -negative strains in Taiwan

We aimed to develop an H. pylori-infected mousemodel using clinically stored strains in Taiwan and totest whether development of H. pylori infection in an invivo animal model is related to the status of the cagA gene. A total of 100 male BALB/cmice, 6-8 weeks old, including 80 in the experimentalgroup and 20 in the control group, were used. Twoclinically stored H. pylori isolates, a cagA-positive and a cagA-negative strain, were selected toinduce the H. pylori infection in half (N = 40) of themice in the experimental group. Bacterial isolates of0.8 × 109 CFU/ml were orally inoculatedin each mouse of the experimental group for threeconsecutive days. Ten mice in the control group weresacrificed to confirm the initial absence of H. pylori.Eight weeks after inoculation of the experimental group and no inoculation of the remaining 10mice of the control group, each mouse was killed.Gastrectomy was then performed for rapid urease test(CLOtest) and histology. In the control group, none of 20 mice had positive results from the CLOtestor histology. In contrast, excluding eight of 80 micethat died before the eighth week, 90.3% (65/72) of themice challenged with H. pylori showed persistent presence of H. pylori by histology. Theseverity of gastritis at the eighth week was moreevident in H. pylori-infected mice than in control andnoninfected mice (P < 0.05). Although gastritis wasmore severe in mice inoculated with thecagA-positive strain than with the cagA-negative strain,the rates of H. pylori infection in mice were notdifferent between cagA-positive and -negative strains(91.4% vs 89.2%, P > 0.05). In summary, storedstrains of H. pylori can be applied to induce aninfection model in BALB/c mice. The less virulentcagA-negative strain can induce H. pylori infection inmice as effectively as the cagA-positive strain. Thehigh prevalence of cagA-positive strains in Taiwanesepatients may be related to factors other than only thecagA gene of the bacteria.

Pretreatment Gastric Histology Is Helpful to Predict the Symptomatic Response After H. pylori Eradication in Patients with Nonulcer Dyspepsia

This study aimed to test whether pretreatment gastric pathology in H. pylori-infected nonulcer dyspepsia (HpNUD) patients is relevant to and predictive of the symptomatic response after H. pylori eradication. Anti-H. pylori triple therapy was administered to 250 HpNUD patients, enrolled as the therapy group. In addition, 60 patients were enrolled as the control group, in which omeprazole was an alternatives to the triple therapy. Pretreatment gastric histology was evaluated thoroughly by the updated Sydney system. A [13C] urea breath test was also performed to evaluate the H. pylori eradication two months and 12 months later. For each patient, the baseline, month 2, and month 12 symptom scores were assessed for the month 2 or month 12 residual symptom ratio (RSR-2m or RSR-12m), calculated from: 100% × month 2 or month 12 score/baseline score. Based on either RSR-2m or RSR-12m, patients were categorized as good response (RSR < 50%), moderate response (50–70%), and poor response (>70%) subgroups in both therapy and control groups to define the short-term and long-term symptomatic responses. Patients with successful H. pylori eradication in the therapy group showed a higher incidence of good symptomatic response (RSR < 50%) than those from the control group (month 2: 30.3 vs 12%, P < 0.05; month 12: 34.7 vs 17.1%, P < 0.05). Univariate and multivariate analysis disclosed that patients with a higher acute inflammation score (AIS) and the lowest incidence of lymphoid follicles (LF) at pretreatment gastric histology are predisposed to having a good symptom response after H. pylori eradication (P < 0.05). For HpNUD patients who have an AIS of more than three and an absence of LF at gastric histology, more than 85% had good short-term (month 2) and long-term (month 12) symptomatic relief after H. pylori eradication. In conclusion, nearly 30% of HpNUD patients can obtain symptomatic relief following H. pylori eradication. The pretreatment gastric histology of HpNUD can be helpful to monitor the symptomatic response after H. pylori eradication.

The selection of triple therapy for Helicobacter pylori eradication in chronic renal insufficiency

Aim: To establish a triple therapy regimen for Helicobacter pylori eradication in patients with chronic renal insufficiency.

Evaluation of Topographic Gastric Histology in H. pylori Infection - A Comparative Study with CLO Test and Bacterial Culture

Endoscopic biopsy is an effective method for the diagnosis of Helicobacter pylori infection. This study sought to determine suitable biopsy locations and the optimal number of specimens for histology examination and to clarify the discrepancies among various invasive diagnostic tests. Forty-seven dys-peptic patients （25M, 22F） were topographically sampled for histology, mucosal rapid urease （CLO）test and bacterial culture. Based on histology, 34 patients (72.3%) had H. pylori infection. The sensitive-ity and specificity of the CLO test and culture were 91.2% & 100% and 79.4% and 100%, repectively. CLO test is known to be a reliable method for the diagnosis of H. pylori infection. In this study , the distribution of H. pylori varied in the stomach and the uneven distribution of bacteria may be respon-sible for the discrepancy in the diagnostic yield. There were 3 patients with a low bacterial load which was confined to the angle or high body of the stomach and with negative CLO test in the antrum. We recommend that at least three biopsies for histology including the antrum of the lesser curvature side, angle and higher body (near cardia), should be sampled to improve the diagnostic accuracy of H. pylori infection and inflammation activity.