Helicobacter pylori pathogenicity and primary antimicrobial resistance in Northern Spain.

BACKGROUND: Helicobacter pylori infection is associated with chronic gastritis, ulcers and gastric cancer. Antimicrobial resistance has increased worldwide affecting the efficacy of current treatments. Most guidelines recommend implementation of regional surveillance of primary antibiotic resistance of H pylori. Only a fraction of individuals infected with H pylori develop gastric diseases which are related to virulence factors of the bacteria. The aims of the study were to determine the primary antimicrobial resistance rates of H pylori and to know the virulence factors prevalence of strains circulating in Southern Europe. MATERIALS AND METHODS: Susceptibility testing by Etest to clarithromycin, levofloxacin, metronidazole, amoxicillin and tetracycline was performed in 102 isolates (99 naïve patients). The prevalence of virulence factors (cagA, vacA, oipA, babA and dupA) was evaluated in 102 H pylori isolates from patients with mild-disease symptoms and in 22 isolates from patients with severe-disease symptoms. RESULTS: Primary resistance rates were 12.1% to clarithromycin, 13.1% to levofloxacin, 24.2% to metronidazole and 0% to amoxicillin and tetracycline. Combined resistance to clarithromycin and levofloxacin was 3% and to clarithromycin and metronidazole 4%. Prevalence of virulence factors in the mild- and severe-disease group was 35.3% and 81.8% for cagA, 20.6% and 54.5% for cagA/vacAs1m1, 94.1% and 95.4% for babA2, 78.4% and 100% for oipA and 30.4% and 18.2% for dupA. CONCLUSIONS: Primary antimicrobial resistance rates were under 15% for clarithromycin and levofloxacin. The prevalence of H pylori carrying the virulent genotype cagA/vacAs1m1 was higher than 20% in the mild-disease and 54% in the severe-disease symptom group.

Helicobacter pylori antimicrobial resistance during a 5-year period (2013-2017) in northern Spain and its relationship with the eradication therapies.

BACKGROUND: Antibiotic resistance is the main cause for Helicobacter pylori therapy failure. Frequently, empirical regimens have been recommended in patients with various H. pylori eradication failures. In patients with H. pylori-resistant to various families of antibiotics, the treatment guided by antimicrobial susceptibility testing allows the achievement of good eradication rates. AIM: To evaluate the effectiveness of susceptibility-guided antimicrobial treatment for H. pylori infection in patients with resistance to one or various families of antibiotics. METHODS: A total of 3170 consecutive patients infected by H. pylori during 2013-2017 were tested for antimicrobial susceptibility. 66.6% patients showed resistance to one antimicrobial, 18.9% to two, and 2.4% to three families of antibiotics. A cohort of 162 H. pylori-positive patients were enrolled in this study. Forty-three with single H. pylori resistance to clarithromycin (CLR) were treated with omeprazole (PPI), amoxicillin (AMX), and levofloxacin (LVX)-OAL (31 subjects) or omeprazole, AMX, and metronidazole (MTZ)-OAM (12 patients) and 77 patients with dual H. pylori resistance (51 to CLR and MTZ, 12 to CLR plus LVX, and 14 to MTZ plus LVX) received OAL or OBTM (PPI, bismuth subcitrate, tetracycline, and MTZ), OAM, and OAC, respectively. Other 42 patients with triple H. pylori resistance (CLR, LVX, and MTZ) were treated with PPI, AMX, and rifabutin-OAR (18 subjects), PPI, AMX, and doxycycline-OAD (8), OADB (7), OBTM (6), and ODBR (3). All subjects received standard doses for 10 days. Eradication rate was confirmed by 13 C-UBT. Adverse events were assessed by a questionnaire. RESULTS: Intention-to-treat analysis demonstrates that eradication rates using triple therapies in patients with H. pylori resistance to one and to two families of antibiotics were 93% and 94.8%, respectively. In subjects with H. pylori-resistant to three families of antibiotics, cure rate was higher in naïve patients treated with OAR-10 days compared to those treated with bismuth-containing quadruple therapies (90% vs 75%). Adverse events were limited (18 of 162, 11.1%), all of them mild-moderate. CONCLUSIONS: The implementation of susceptibility-guided triple therapy for 10 days leads to eradication rate ≥95% in naïve patients with H. pylori resistance to one or two families of antimicrobials. In naïve patients with H. pylori resistance to three families, OAR treatment achieved a 90% of eradication.

A 1 year course of starch- and sucrose-reduced diet used by irritable bowel syndrome patients with diarrhoea and the effect of genetic variants.

Background: Irritable bowel syndrome is a heterogeneous syndrome and it is difficult to find an effective treatment. Previously, a starch- and sucrose-reduced diet (SSRD) demonstrated promising short-term outcomes. It was proposed that genetic variants in the sucrose-isomaltase gene might influence this success. Our aim in this work was to extend the follow-up study to 1 year and to analyse the effect of the genetic variants of genes involved in starch and sucrose metabolism. Methods: IBS-SSS questionnaire, IBS-QoL questionnaire and questionnaires about adherence, difficulty and food assessment were sent to 34 patients after 6 months and 1 year after the end of the dietary intervention. In addition, 11 genes involved in sucrose and starch metabolism were sequenced. Results: Twenty-three participants responded to the 6 months follow-up and 16 to the 1 year follow-up. IBS-SSS total value increased 59.71% in the 6 months follow-up compared with the end of the intervention (p = 0.0018), and 55.39% in the 1 year follow-up (p = 0.0166); while IBS-QoL score decreased 24.09% (p = 0.0002) and 18.07% (p = 0.0022), respectively. The adherence decreased by 29.11% (p = 4.8 × 10-5) and 27.21% (p = 0.0054), respectively. In addition, carriers of pathogenic variants on the SI gene showed a slightly better performance than non-carriers. Finally, the participants showed less satisfaction over time with 18 allowed foods in the diet. Conclusion: Over time the SSRD is difficult to follow and the genotype might affect the performance of the diet. Since this diet could be a promising therapeutic option, a larger cohort needs to be analysed to validate the results and to compare it with other diets.

The effect of starch- and sucrose-reduced diet accompanied by nutritional and culinary recommendations on the symptoms of irritable bowel syndrome patients with diarrhoea.

Background: Irritable bowel syndrome (IBS) is a common gastrointestinal condition which entails a high burden in the quality of life (QoL) of patients. Nutritional interventions have been proposed to alleviate symptoms, since still no effective treatments exist for IBS. Objectives: Our aim is to analyse the feasibility of the use of starch- and sucrose-reduced diet (SSRD). Design: In this study, we used a SSRD accompanied by nutritional and culinary recommendations to measure the effects in IBS patients with diarrhoea. Methods: In all, 34 participants completed a 4-week nutritional intervention based on SSRD. Symptoms, QoL and dietary habits were assessed by several questionnaires that were completed at the beginning, daily, after 2 weeks, at the end, and after 2 months. Results: 85.29% of the participants reached the primary endpoint [reduction of 50 points or more in IBS-symptom severity scale (SSS)], and 58.82% the secondary endpoint (reduction of 50% or more in IBS-SSS). The relief of symptoms and improvement of the QoL were significant after 2 weeks of intervention, at the end and after 2 months. Dietary habits were consistent with the diet and high adherence was achieved. Conclusions: SSRD and individualized nutritional and culinary guidance improved symptoms and QoL of IBS patients with diarrhoea, with a high adherence.

Clarithromycin resistance in Helicobacter pylori and its molecular determinants in Northern Spain, 2013-2015.

OBJECTIVES: Clarithromycin resistance (CLR-R) is the main reason for failure of Helicobacter pylori infection treatment, which is frequently empirically prescribed due to the erroneous belief that culture for susceptibility testing is difficult. The aim of this study was to determine CLR-R in a region of southern Europe and to evaluate the utility of a PCR sequencing assay applied on gastroduodenal biopsies in detecting H. pylori and clarithromycin (CLR) susceptibility. METHODS: The susceptibility of all H. pylori isolates obtained by culture during 2013-2015 was determined by Etest. During 2014-2015, H. pylori detection and CLR susceptibility were also studied by PCR followed by sequencing performed on gastroduodenal biopsies. Point mutations in the 23S rRNA gene were studied in all CLR-resistant isolates in 2014. RESULTS: Of 1986 H. pylori isolates obtained by culture (63 from children and 1923 from adults), 349 (17.6%) were CLR-resistant [21/63 (33.3%) in children and 328/1923 (17.1%) in adults; P<0.001], of which 31.5% were also resistant to levofloxacin. The main mutations detected were A2147G (79.8%), A2146G (17.2%) and A2146C (2%). Concordance between the PCR sequencing assay on biopsies and CLR susceptibility by Etest after culture was 89.8%. CONCLUSIONS: CLR-R was high in Gipuzkoa, northern Spain. The molecular PCR method performed directly on biopsies was a good alternative to the traditional Etest susceptibility method and was an aid when culture was non-viable.