Curcumin and Colorectal Cancer: From Basic to Clinical Evidences.

Curcumin diffuses through cell membranes into the endoplasmic reticulum, mitochondria, and nucleus, where it exerts actions, as an antioxidant property. Therefore, its use has been advocated for chemopreventive, antimetastatic, and anti-angiogenic purposes. We conducted a literature review to summarize studies investigating the relationship between curcumin and colorectal cancer (CRC). In vitro studies, performed on human colon cancer cell lines, showed that curcumin inhibited cellular growth through cycle arrest at the G2/M and G1 phases, as well as stimulated apoptosis by interacting with multiple molecular targets. In vivo studies have been performed in inflammatory and genetic CRC animal models with a chemopreventive effect. To improve curcumin bioavailability, it has been associated with small particles that increase its absorption when orally administered with excellent results on both inflammation and carcinogenesis. Curcumin has been used, moreover, as a component of dietetic formulations for CRC chemoprevention. These combinations showed in vitro and in vivo anticarcinogenetic properties in inflammation-related and genetic CRC. A synergic effect was suggested using an individual constituent dosage, which was lower than that experimentally used "in vivo" for single components. In conclusion, curcumin falls within the category of plant origin substances able to prevent CRC in animals. This property offers promising expectations in humans.

Human Leukocyte Antigen (HLA) Haplotype Does Not Influence the Inflammatory Pattern of Duodenal Lymphocytosis Linked to Irritable Bowel Syndrome.

Background and objectives: Duodenal lymphocytosis (DL) is a condition characterized by enhanced infiltration of intraepithelial lymphocytes (IELs) in the duodenal mucosa, and it can be linked to both gluten- and non-gluten-related diseases, such as irritable bowel syndrome (IBS). Materials and methods: We retrospectively selected patients with DL linked to IBS. Formalin-embedded biopsy samples of the duodenum were collected. CD3 lymphocyte immunohistochemistry was used for IELs. The real-time polymerase chain reaction was used to quantify the amount of mRNA coding for tissue transglutaminase 2 (tTG2), interferon-gamma (IFNγ), toll-like receptor 2 (TLR2), and myeloid differentiation primary response 88 (MyD88). All subjects underwent DQ2-8 haplotype analysis. Controls were represented by subjects with IBS without DL. Results: Thirty-two patients with IBS-DL were retrospectively recruited. Fourteen subjects (43.8%) had a DQ2-8 haplotype. DQ2-8 positive subjects had similar levels compared to negative ones for tTG2, IFNγ, TLR2, and MyD88. Cigarette smoke did not influence molecular expression in our study. Smokers had a statistically higher IELs count than non-smokers (54.2 ± 7.7 vs. 36.0 ± 8.8, p < 0.001). A significant, direct correlation between IELs and duodenal expression of IFNγ was found (r = 0.36, p = 0.04). Conclusions: IBS with DL showed higher expression of inflammatory markers than controls, but DQ2-8 haplotype did not seem to affect their expression. Smoking might increase IELs infiltration.

Chemoprevention of inflammation-related colorectal cancer by silymarin-, acetyl-11-keto-beta-boswellic acid-, curcumin- and maltodextrin-enriched dietetic formulation in animal model.

On the basis of preliminary in vitro experience, we assessed whether an enriched nutritional formulation with estrogen receptor (ER)-beta agonist and anti-inflammatory properties may prevent inflammation-associated colorectal cancer (CRC) in an animal model. Study sample enclosed 110 C57BL/6J male mice. Forty underwent dietary supplement safety assessment (20 standard diet and 20 enriched formulation). Seventy were treated with azoxymethane (AOM)/dextran sulfate sodium and divided into two groups: 35 received standard diet and 35 enriched formulation (curcumin, boswellic acids, silymarin and maltodextrins). Miniature colonoscopy demonstrated colitis and solid lesion development in five mice/group 100 days after first AOM injection. Mice were killed after 10 days. In each group, four subgroups received intraperitoneal bromodeoxyuridine (BrdU) injection at 24th/48th/72nd/96th hour before killing. Anti-inflammatory effect and chemoprevention were evaluated by lesion number/size, histological inflammation/dysplasia/neoplasia assessment, pro-inflammatory cytokine messenger RNA (mRNA), ER-beta/ER-alpha/BrdU immunohistochemistry and TUNEL immunofluorescence. Standard formulation assumption was associated with colon shortening compared with enriched one (P = 0.04), which reduced solid lesion number and size (P < 0.001 for both), histological inflammation score (P = 0.04), pro-inflammatory cytokine mRNA expression (P < 0.001), number of low-grade dysplasia (LGD; P = 0.03) and high-grade dysplasia (P < 0.001) areas. CRC was observed in 69.6% in standard and 23.5% in enriched formulation assuming animals (P < 0.001). Enriched formulation induced lower ER-alpha expression in CRC (P < 0.001) and higher ER-beta expression in LGD (P < 0.001) being associated to higher epithelial turnover (BrdU; P<0.001) in normal mucosa and increased apoptosis in LGD and CRC (P < 0.001 for both). Our results are promising for a successful anti-inflammatory and chemopreventive effect of enriched formulation in CRC arising from inflamed tissue.

Occurrence of Legionella in showers at recreational facilities.

Critical environments, including water systems in recreational settings, represent an important source of Legionella pneumophila infection in humans. In order to assess the potential risk for legionellosis, we analyzed Legionella contamination of water distribution systems in 36 recreational facilities equipped with swimming pools. One hundred and sixty water samples were analyzed from shower heads or taps located in locker rooms or in bathrooms. By culture method and polymerase chain reaction, 41/160 samples were positive for Legionella from 12/36 recreational centers. Hotels (57.1%) and sports centers (41.2%) were the most contaminated. L. pneumophila serotypes 2-14 (25/41) were more frequently found than serotype 1 (10/41). Samples at temperature ≥30 °C were more frequently positive than samples at temperature <30 °C (n = 39 vs n = 2, p < 0.00001). The presence of L. pneumophila was investigated by comparison with heterotrophic plate count (HPC), an indicator of water quality. The presence of L. pneumophila was associated more frequently with high and intermediate HPC load at 37 °C, therefore should be considered a potential source when HPC at 37 °C is >10 CFU/mL. Maintenance, good hygiene practices, interventions on the hydraulic system and regular controls must be implemented to minimize exposure to L. pneumophila infection risk.

DPPTE Thiolipid Self-Assembled Monolayer: A Critical Assay.

Supported lipid membranes represent an elegant way to design a fluid interface able to mimic the physicochemical properties of biological membranes, with potential biotechnological applications. In this work, a diacyl phospholipid, the 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE), functionalized with a thiol group, was immobilized on a gold surface. In this molecule, the thiol group, responsible for the Au-S bond (45 kJ/mol) is located on the phospholipid polar head, letting the hydrophobic chain protrude from the film. This system is widely used in the literature but is no less challenging, since its characterization is not complete, as several discordant data have been obtained. In this work, the film was characterized by cyclic voltammetry blocking experiments, to verify the SAM formation, and by reductive desorption measurements, to estimate the molecular density of DPPTE on the gold surface. This value has been compared to that obtained by quartz crystal microbalance measurements. Ellipsometry and impedance spectroscopy measurements have been performed to obtain information about the monolayer thickness and capacitance. The film morphology was investigated by atomic force microscopy. Finally, Monte Carlo simulations were carried out, in order to gain molecular information about the morphologies of the DPPTE SAM and compare them to the experimental results. We demonstrate that DPPTE molecules, incubated 18 h below the phase transition temperature (T = 41.1 ± 0.4 °C) in ethanol solution, are able to form a self-assembled monolayer on the gold surface, with domain structures of different order, which have never been reported before. Our results make possible rationalization of the scattered results so far obtained on this system, giving a new insight into the formation of phospholipids SAMs on a gold surface.

Helicobacter pylori DNA isolation in the stool: an essential pre-requisite for bacterial noninvasive molecular analysis.

PURPOSE: Real-time polymerase chain reaction (RT-PCR) is a widely used technique for bacterial and viral infection diagnosis. Herein, we report our preliminary experience in retrieving H. pylori genetic sequences in stools and analyzing genotypic clarithromycin resistance by RT-PCR (noninvasive), with the aim of comparing this procedure with that performed on biopsy samples (invasive). MATERIALS AND METHODS: After 'in vitro' demonstration of H. pylori DNA detection from pure and stool-mixed bacteria, 52 consecutive patients at the first diagnosis of infection were investigated. DNA was extracted from biopsy tissue and stool samples (THD® Fecal Test, Italy). RT-PCR was performed to detect 23S rRNA encoding bacterial subunit gene and search A2143G, A2142C, A2142G point mutations for clarithromycin resistance assessment. RESULTS: RT-PCR showed H. pylori positive DNA in all infected patients with full concordance between tissue and stool detection (100%). We found A2143G mutation in 10 (19.2%), A2142G in 4 (7.7%) and A2142C in 5 (9.6%) patients; there was a full agreement between biopsy and fecal samples. A2143G was found in all the four A2142G positive cases and in three out of the five A2142C positive strains. Overall clarithromycin resistance rate in our series was 23%. CONCLUSIONS: Despite the need of confirmation on large sample, stool RT-PCR analysis could represent a feasible tool to detect H. pylori DNA sequences and antibiotic resistance point mutations. As compared to tissue molecular analysis, this technique is noninvasive, with potential advantages such as improvement of patient compliance, reduction of diagnostic procedure time/cost and improvement of therapeutic outcome.

Macronutrient intakes in obese subjects with or without small intestinal bacterial overgrowth: an alimentary survey.

OBJECTIVE: Obesity is a multifactorial disorder with a possible microbiota derangement in its pathogenesis. Moreover, in obese patients the likelihood of small intestinal bacterial overgrowth (SIBO) is greater than in controls, although few studies are currently available. This study investigates the prevalence of SIBO and the possible role of dietary macronutrients in obesity. MATERIALS AND METHODS: Sixty obese patients and normal lean controls were enrolled for SIBO detection. Diagnosis of SIBO was performed by a glucose breath test. A 24-hour recall questionnaire was administered to investigate macronutrient daily intake between the two obese patient subgroups (with/without SIBO). RESULTS: The presence of SIBO in obese and controls was respectively 23.3% and 6.6% (p = 0.02, OR = 4.26, 95% Confidence interval = 1.31-13.84). Obese patients with SIBO ingested more carbohydrates (252.75 ± 30.53 vs 201 ± 70.76 g/day, p = 0.01), more refined sugars (104.15 ± 28.69 vs 73.32 ± 44.93 g/day, p = 0.02) and less total and insoluble fibers (9.6 ± 1.97 vs 14.65 ± 8.80 g/day, p = 0.04 and 4.7 ± 1.11 vs 8.82 ± 5.80 g/day, p = 0.01, respectively). There were no significant differences in lipid and protein intake between the two groups. CONCLUSIONS: SIBO is widespread in obese subjects. Carbohydrates might promote the development of SIBO in obesity and fibers provide a protective function. Our results suggest a close relationship between diet and SIBO in obesity, thus supporting a possible role for intestinal microbiota.

Helicobacter pylori, liver cirrhosis, and portal hypertension: an updated appraisal.

OBJECTIVE: Helicobacter pylori (H. pylori) is the most common cause of gastritis and peptic ulcer. However, H. pylori is even involved in extragastric diseases, and it has been hypothesized that H. pylori could be a risk factor for several hepatic diseases. For instance, a direct involvement of H. pylori in the development of portal hypertension (PH) in cirrhotic patients has been postulated. METHODS: We performed a literature search in major databases to elucidate the relationship between H. pylori, portal hypertension, and liver cirrhosis. RESULTS: The effect of H. pylori on PH may be multifactorial. Endothelial dysfunction, alterations in the vasodilating dynamics, and neoangiogenesis are the most appealing theories about this issue, but the proofs come mainly from experimental studies, therefore a solid pathophysiological basis is still to be demonstrated. Congestive gastropathy (CG) and gastric antral vascular ectasia (GAVE) are two common endoscopic entities responsible for acute/chronic upper gastrointestinal bleeding, and a link with H. pylori has been hypothesized: the gastric mucosa, exposed to H. pylori, could develop both inflammatory microcirculatory alterations and thrombi, resembling the histologic pattern of GAVE. CONCLUSIONS: Despite clues for an association between H. pylori and PH have been shown, these evidences are mostly experimental, therefore, in the absence of a direct proof on human beings, the role of H. pylori in the development of PH is uncertain. However, since this germ may be a cause of peptic ulcer, it should be found and eradicated in cirrhotic patients to reduce the risk of blood loss anemia.

Possible role of nuclear factor erythroid 2-related factor 2 in the progression of human colon precancerous lesions.

BACKGROUND: Increased levels of oxidative stress/cell inflammation contribute to colorectal cancer (CRC) onset. Nuclear factor-erythroid 2-related factor 2 (Nrf2) and its controlled growth factor erv1-like (Gfer) gene regulate redox-sensitive and anti-inflammatory mechanisms, respectively, which can contribute to promoting cancer development. AIM: We evaluated Nrf2 and Gfer RNA expression and Nrf2 protein expression in colon mucosa in order to establish their possible involvement in the early stage of CRC. METHODS: Forty subjects were enrolled after a histological evaluation of their colon biopsies. They included 20 subjects with a sporadic colorectal adenoma (SpCA group) and 20 without precancerous lesions (controls). Biopsy samples were processed for gene expression analysis and protein expression, using Real-time PCR and immunofluorescence confocal microscopy, respectively. RESULTS: Nrf2 and Gfer mRNA expression were significantly reduced (p=0.007 and p<0.003, respectively) in SpCA tissues compared to normal mucosa from controls. Furthermore, immunofluorescence analysis confirmed a relevant reduction of Nrf2 in SpCA tissue compared to normal tissue from controls. CONCLUSIONS: Our data confirm the hypothesis that Nrf2 and Gfer expression may be involved in the initial hits contributing to the multistep process of colon carcinogenesis. Further larger studies are needed to confirm if Nrf2 and Gfer are potential risk/prognostic factors for cancer development.

Phenotypic and genotypic Helicobacter pylori clarithromycin resistance and therapeutic outcome: benefits and limits.

INTRODUCTION: Primary clarithromycin resistance is increasing worldwide, and it has been regarded as the main factor reducing the efficacy of Helicobacter pylori therapy. However, the clinical consequence of either phenotypic or genotypic resistance still remains unclear. This study aimed to evaluate: (i) the concordance between phenotypic (culture) and genotypic (real-time PCR) tests in assessing primary clarithromycin resistance; and (ii) the role of both in therapeutic outcome. METHODS: A post hoc subgroup study was selected from a double-blind, placebo-controlled trial, enrolling 146 patients with dyspepsia or peptic ulcers never previously treated. Real-time PCR and Etest on bacterial culture for assessing clarithromycin resistance were performed. [(13)C]urea breath test (UBT), histology and rapid urease tests at entry and UBT after 4-8 weeks were used to assess infection and eradication. All patients received a 10 day therapy. RESULTS: Prevalence of clarithromycin phenotypic resistance was significantly lower as compared with genotypic resistance (18.4% versus 37.6%, P < 0.001). A concordance between the two methods was present in 71.2% of cases. A significant difference in the eradication rate was seen between clarithromycin-susceptible and -resistant strains, when assessed with either Etest (92.4% versus 55.5%, P < 0.001) or a PCR-based method (94.5% versus 70.9%; P < 0.001). Of note, the eradication rate showed the lowest value (30.7%) when phenotypic bacterial resistance was genetically linked to the A2143G point mutation. CONCLUSIONS: This study showed that: (i) there is a relevant discordance between the two methods; and (ii) phenotypic clarithromycin resistance markedly reduces H. pylori eradication when it is linked to a specific point mutation.

The Puzzle of Coccoid Forms of Helicobacter pylori: Beyond Basic Science.

Helicobacter pylori (H. pylori) may enter a non-replicative, non-culturable, low metabolically active state, the so-called coccoid form, to survive in extreme environmental conditions. Since coccoid forms are not susceptible to antibiotics, they could represent a cause of therapy failure even in the absence of antibiotic resistance, i.e., relapse within one year. Furthermore, coccoid forms may colonize and infect the gastric mucosa in animal models and induce specific antibodies in animals and humans. Their detection is hard, since they are not culturable. Techniques, such as electron microscopy, polymerase chain reaction, loop-mediated isothermal amplification, flow cytometry and metagenomics, are promising even if current evidence is limited. Among the options for the treatment, some strategies have been suggested, such as a very high proton pump inhibitor dose, high-dose dual therapy, N-acetycysteine, linolenic acid and vonoprazan. These clinical, diagnostic and therapeutic uncertainties will represent fascinating challenges in the future.

Silymarin, boswellic acid and curcumin enriched dietetic formulation reduces the growth of inherited intestinal polyps in an animal model.

BACKGROUND: Some substances of plant origin have been reported to exert an effect in reducing intestinal neoplasm development, especially in animal models. Adenomatous polyposis coli multiple intestinal neoplasia - ApcMin/+ is the most studied murine model of genetic intestinal carcinogenesis. AIM: To assess whether an enriched nutritional formulation (silymarin, boswellic acid and curcumin) with proven "in vitro" and "in vivo" anti-carcinogenetic properties may prevent inherited intestinal cancer in animal model. METHODS: Forty adenomatous polyposis coli multiple intestinal neoplasia - ApcMin/+ mice were used for the study of cancer prevention. They were divided into two groups: 20 assumed standard and 20 enriched diet. At the 110th d animals were sacrificed. In each group, four subgroups received intraperitoneal bromodeoxyuridine injection at different times (24, 48, 72 and 96 h before the sacrifice) in order to assess epithelial turnover. Moreover, we evaluated the following parameters: Intestinal polypoid lesion number and size on autoptic tissue, dysplasia and neoplasia areas by histological examination of the whole small intestine, inflammation by histology and cytokine mRNA expression by real-time polymerase chain reaction, bromodeoxyuridine and TUNEL immuno-fluorescence for epithelial turnover and apoptosis, respectively. Additionally, we performed western blotting analysis for the expression of estrogen alpha and beta receptors, cyclin D1 and cleaved caspase 3 in normal and polypoid tissues. RESULTS: Compared to standard, enriched diet reduced the total number (203 vs 416) and the mean ± SD/animal (12.6 ± 5.0 vs 26.0 ± 8.8; P < 0.001) of polypoid lesions. In enriched diet group a reduction in polyp size was observed (P < 0.001). Histological inflammation and pro-inflammatory cytokine expression were similar in both groups. Areas of low-grade dysplasia (P < 0.001) and intestinal carcinoma (IC; P < 0.001) were significantly decreased in enriched diet group. IC was observed in 100% in standard and 85% in enriched formulation assuming animals. Enriched diet showed a faster epithelial migration and an increased apoptosis in normal mucosa and low-grade dysplasia areas (P < 0.001). At western blotting, estrogen receptor beta protein was well expressed in normal mucosa of enriched and standard groups, with a more marked trend associated to the first one. Estrogen receptor alpha was similarly expressed in normal and polypoid mucosa of standard and enriched diet group. Cleaved caspase 3 showed in normal mucosa a stronger signal in enriched than in standard diet. Cyclin D1 was more expressed in standard than enriched diet group of both normal and polypoid tissue. CONCLUSION: Our results are suggestive of a chemo-preventive synergic effect of the components (silymarin, boswellic acid and curcumin) of an enriched formulation in inherited IC. This effect may be mediated by the reduction of epithelial proliferation, the increase of apoptosis and the acceleration of villous cell renewal due to dietary formulation intake.

Helicobacter pylori Primary and Secondary Genotypic Resistance to Clarithromycin and Levofloxacin Detection in Stools: A 4-Year Scenario in Southern Italy.

Antibiotic resistance has become an emerging problem for treating Helicobacter pylori (H. pylori) infection. Clarithromycin and levofloxacin are two key antibiotics used for its eradication. Therefore, we reviewed our experience with genotypic resistance analysis in stools to both clarithromycin and levofloxacin in the last four years to evaluate time trends, both in naive and failure patients. Patients collected a fecal sample using the THD fecal test device. Real-time polymerase chain reaction was performed to detect point mutations conferring resistance to clarithromycin (A2142C, A2142G, and A2143G in 23S rRNA) and levofloxacin (substitutions at amino acid position 87 and 91 of gyrA). One hundred and thirty-five naive patients were recruited between 2017-2020. Clarithromycin resistance was detected in 37 (27.4%). The time trend did not show any significant variation from 2017 to 2020 (p = 0.33). Primary levofloxacin resistance was found in 26 subjects (19.2%), and we observed a dramatic increase in rates from 2017 (10%) to 2018 (3.3%), 2019 (20%), and 2020 (37.8%). Ninety-one patients with at least one eradication failure were recruited. Secondary resistance to clarithromycin and levofloxacin was found in 59 (64.8%) and 45 patients (59.3%), respectively. In conclusion, our geographic area has a high risk of resistance to clarithromycin. There is also a progressive spreading of levofloxacin-resistant strains.

Expression and localization of augmenter of liver regeneration in human muscle tissue.

Mitochondrial DNA (mt-DNA) disorders and abnormal regulation of nuclear-derived proteins devoted to the cross-talk between the two cellular genomes have recently interested researchers in the field of neuromuscular diseases. We have identified, isolated and sequenced a new gene, augmenter of liver regeneration (ALR) that stimulates in vivo hepatocyte proliferation and up-regulates mt-DNA expression and ATP production. ALR protein (Alrp) is mainly located, in rat, in the mitochondrial inter-membrane space and its mRNA is particularly abundant in brain, muscle, testis and liver, tissues whose activity is mostly dependent on mitochondrial metabolism. Studies on rat Alrp sequence revealed the presence of homologous amino-acid sections into proteins derived from mouse, human, Drosophyla, plants and even DNA viruses. In this article, we evaluated ALR expression in normal human muscular tissues, both as protein and as mRNA. The data, obtained by molecular biology, immunohistochemistry and electron microscopy, demonstrated that: (i) Alrp and ALR mRNA are present in human muscular tissue; (ii) Alrp is particularly expressed in muscular fibres rich in mitochondria; (iii) Alrp is localized in the mitochondrial inter-membrane space or associated to mitochondrial cristae; and (iv) in subjects younger then 35 years of age, ALR mRNA expression is different between male and female subjects. In conclusion, the present data set Alrp, as a factor associated with mitochondria also in human tissue, call for future studies aimed at establishing Alrp as an important factor involved in the molecular events that trigger neuromuscular diseases.

Helicobacter pylori vacA arrangement and related diseases: a retrospective study over a period of 15 years.

Peptic ulcer disease incidence is decreasing. Both s1m1 and s1m2 vacA gene combinations of Helicobacter pylori have been associated with the development of major gastroduodenal diseases. This study assessed whether H. pylori vacA gene arrangement changed over 15 years in a Southern Italy area. H. pylori-positive patients observed in January-June 1989 and January-June 2005 were selected. Histological specimens were retrieved to extract DNA for vacA arrangement characterization (mid-m and peptide signal-s regions) by using the polymerase chain reaction. Fifty-nine patients in the first period and 56 matched patients in the second period were evaluated. A correlation between s1 presence and intestinal metaplasia at histology was found. Overall, the s1m1 combination increased (P < 0.01) and s2m2 decreased (P < 0.001) during the study period. In detail, s1m1 (P < 0.05) and s1m2 (P < 0.01) increased, and s2m2 decreased (P < 0.001) in dyspeptic patients, while only s1m1 increased (P < 0.01) in peptic ulcer patients. Finally, few cases of s2m1 combination in both series were found. Our results show some unexpected aspects that require confirmation. In detail, the increased prevalence of potential more virulent H. pylori strains contrasts with peptic ulcer incidence reduction.

Biological markers for non-celiac gluten sensitivity: a question awaiting for a convincing answer.

Non Celiac Gluten Sensitivity (NCGS) is characterized by immunological, morphological or symptomatic manifestations precipitated by gluten ingestion in individuals without celiac disease (CD). The most important challenge in NCGS is the diagnosis, currently based only on clinical observation. The "Salerno criteria" have been pointed out to achieve a reliable diagnosis even if they lack immediacy and practicality, thus making questionable patient's adherence. Therefore, biological indicators supporting the clinical diagnosis of NCGS are advisable. For these reasons, many attempts have been performed in order to identify possible serological, immunological, histopathological, immunohistochemical and pathophysiological aspects characterizing this condition with the aim of using them for diagnostic purposes. In the present narrative review, we carried out an update of the current scenario of potential markers of NCGS. The main fault of available studies is that, in most cases investigations have been pointed out towards molecules, which cannot be searched in the current laboratories of clinical analysis. Therefore, the matter has been confined within basic research. Additionally, in these studies, sensitivity and specificity of biological markers were not computable. This is a relevant limit, since an ideal test for NCGS should have a good discriminative power against both CD and other causes of microscopic enteritis. Until now, serological tests have failed, while the search for a soluble marker indicative of activation of innate immune system as well as immunohistochemistry could be the promising bases for the development of appropriate investigations in the future.

New fecal test for non-invasive Helicobacter pylori detection: A diagnostic accuracy study.

AIM: To assess the diagnostic accuracy of a new fecal test for detecting Helicobacter pylori (H. pylori), using13C-urea breath test as the reference standard, and explore bacterial antibiotic resistance. METHODS: We conducted a prospective two-center diagnostic test accuracy study. We enrolled consecutive people≥ 18 years without previous diagnosis of H. pylori infection, referred for dyspepsia between February and October 2017. At enrollment, all participants underwent 13C-urea breath test. Participants aged over 50 years were scheduled to undergo upper endoscopy with histology. Participants collected stool samples 1-3 d after enrollment for a new fecal investigation (THD fecal test). The detection of bacterial 23S rRNA subunit gene indicated H. pylori infection. We also used the index diagnostic test to examine mutations conferring resistance to clarithromycin and levofloxacin. Independent investigators analyzed index test and reference test standard results blinded to the other test findings. We estimated sensitivity, specificity, positive (PPV) and negative (NPV) predictive value, diagnostic accuracy, positive and negative likelihood ratio (LR), together with 95% confidence intervals (CI). RESULTS: We enrolled 294 consecutive participants (age: Median 37.0 years, IQR: 29.0-46.0 years; men: 39.8%). Ninety-five (32.3%) participants had a positive13C-urea breath test. Twenty-three (7.8%) participants underwent upper endoscopy with histology, with a full concordance between 13C-urea breath test and histology in detecting H. pylori infection. Four (1.4%) out of the 294 participants withdrew from the study after the enrollment visit and did not undergo THD fecal testing. In the 290 participants who completed the study, the THD fecal test sensitivity was 90.2% (CI: 84.2%-96.3%), specificity 98.5% (CI:96.8%-100%), PPV 96.5% (CI: 92.6%-100%), NPV 95.6% (CI: 92.8%-98.4%), accuracy 95.9% (CI: 93.6%-98.2%), positive LR 59.5(CI: 19.3-183.4), negative LR 0.10 (CI: 0.05-0.18). Out of 83 infected participants identified with the THD fecal test, 34 (41.0%) had bacterial genotypic changes consistent with antibiotic-resistant H. pylori infection. Of these, 27 (32.5%) had bacterial strains resistant to clarithromycin, 3 (3.6%) to levofloxacin, and 4 (4.8%) to both antibiotics. CONCLUSION: The THD fecal test has high performance for the non-invasive diagnosis of H. pylori infection while additionally enabling the assessment of bacterial antibiotic resistances.

Noninvasive molecular analysis of Helicobacter pylori: Is it time for tailored first-line therapy?

The main problem of Helicobacter pylori (H. pylori) infection management is linked to antibiotic resistances. This phenomenon has grown in the last decade, inducing a dramatic decline in conventional regimen effectiveness. The causes of resistance are point mutations in bacterial DNA, which interfere with antibiotic mechanism of action, especially clarithromycin and levofloxacin. Therefore, international guidelines have recently discouraged their use in areas with a relevant resistance percentage, suggesting first-line schedules with expected high eradication rates, i.e., bismuth containing or non-bismuth quadruple therapies. These regimens require the daily assumption of a large number of tablets. Consequently, a complete adherence is expected only in subjects who may be motivated by the presence of major disorders. However, an incomplete adherence to antibiotic therapies may lead to resistance onset, since sub-inhibitory concentrations could stimulate the selection of resistant mutants. Of note, a recent meta-analysis suggests that susceptibility tests may be more useful for the choice of first than second-line or rescue treatment. Additionally, susceptibility guided therapy has been demonstrated to be highly effective and superior to empiric treatments by both meta-analyses and recent clinical studies. Conventional susceptibility test is represented by culture and antibiogram. However, the method is not available everywhere mainly for methodology-related factors and fails to detect hetero-resistances. Polymerase chain reaction (PCR)-based, culture-free techniques on gastric biopsy samples are accurate in finding even minimal traces of genotypic resistant strains and hetero-resistant status by the identification of specific point mutations. The need for an invasive endoscopic procedure has been the most important limit to their spread. A further step has, moreover, been the detection of point mutations in bacterial DNA fecal samples. Few studies on clarithromycin susceptibility have shown an overall high sensitivity and specificity when compared with culture or PCR on gastric biopsies. On these bases, two commercial tests are now available although they have shown some controversial findings. A novel PCR method showed a full concordance between tissue and stool results in a preliminary experience. In conclusion, despite poor validation, there is increasing evidence of a potential availability of noninvasive investigations able to detect H. pylori resistances to antibiotics. These kinds of analysis are currently at a very early phase of development and caution should be paid about their clinical application. Only further studies aimed to evaluate their sensitivity and specificity will afford novel data for solid considerations. Nevertheless, noninvasive molecular tests may improve patient compliance, time/cost of infection management and therapeutic outcome. Moreover, the potential risk of a future increase of resistance to quadruple regimens as a consequence of their use on large scale and incomplete patient adherence could be avoided.

Claritromycin resistance and Helicobacter pylori genotypes in Italy.

The relationship between H. pylori clarithromycin resistance and genetic pattern distribution has been differently explained from different geographic areas. Therefore, we aimed to assess the clarithromycin resistance rate, to evaluate the bacterial genetic pattern, and to search for a possible association between clarithromycin resistance and cagA or vacA genes. This prospective study enrolled 62 consecutive H. pylori infected patients. The infection was established by histology and rapid urease test. Clarithromycin resistance, cagA and vacA status, including s/m subtypes, were assessed on paraffin-embedded antral biopsy specimens by TaqMan real time polymerase chain reaction (PCR). Primary clarithromycin resistance was detected in 24.1 % of cases. The prevalence of cagA was 69.3 %, and a single vacA mosaicism was observed in 95.1 % cases. In detail, the s1m1 was observed in 23 (38.9 %) patients, the s1m2 in 22 (37.2 %), and the s2m2 in 14 (23.7 %), whereas the s2m1 combination was never found. The prevalence of cagA and the vacA alleles distribution did not significantly differ between susceptible and resistant strains. Primary clarithromycin resistance is high in our area. The s1m1 and s1m2 are the most frequent vacA mosaicisms. There is no a relationship between clarithromycin resistance and bacterial genotypic pattern and/or cagA positivity.