Helicobacter pylori infection is associated with decreased odds for eosinophilic esophagitis in Mexican patients. / La infección por Helicobacter pylori se asocia con disminución del riesgo de esofagitis eosinofílica en pacientes mexicanos.

BACKGROUND: The incidence of eosinophilic esophagitis (EoE) is increasing in some regions of the world. Retrospective studies have found an inverse association with Helicobacter pylori infection (H. pylori). A recent prospective study has questioned this relationship. We aimed to evaluate this relationship in Mexican patients. PATIENTS AND METHODS: We evaluated adult patients without prior eradication of H. pylori. Cases were defined by the presence of esophageal symptoms and >15 eosinophils/high power field (HPF) in the esophageal biopsy. Controls were defined by the presence of <15 eosinophils/HPF in esophageal biopsy. H. pylori infection was defined by histology. Patients were matched by age and gender assigning four controls per case. RESULTS: We included 190 patients: 38 cases and 152 controls. Cases had higher frequency of atopy, dysphagia, food impaction, peripheral eosinophilia, and endoscopic EoE abnormalities. The overall prevalence of H. pylori was 63.6%. Cases had significantly lower prevalence of H. pylori than controls (36.8% vs. 70.4%, OR 0.21 95% CI 0.08-0.69, p = 0.001). Atopic patients had lower prevalence of H. pylori than non-atopic: 13.1% vs. 50.5% (OR 0.20, 95% CI 0.06-0.69, p < 0.001), particularly allergic rhinitis and food allergy. CONCLUSIONS: We observed an inverse relationship between H. pylori and EoE as well as atopy. Studies in experimental models of EoE that clarify the role of H. pylori in this interaction are required, as well as robust studies that include other factors (socioeconomic, cultural, microbiota, etc.) in order to clarify this relationship.

Review of the Impact of Biofilm Formation on Recurrent Clostridioides difficile Infection.

Clostridioides difficile infection (CDI) may recur in approximately 10-30% of patients, and the risk of recurrence increases with each successive recurrence, reaching up to 65%. C. difficile can form biofilm with approximately 20% of the bacterial genome expressed differently between biofilm and planktonic cells. Biofilm plays several roles that may favor recurrence; for example, it may act as a reservoir of spores, protect the vegetative cells from the activity of antibiotics, and favor the formation of persistent cells. Moreover, the expression of several virulence genes, including TcdA and TcdB toxins, has been associated with recurrence. Several systems and structures associated with adhesion and biofilm formation have been studied in C. difficile, including cell-wall proteins, quorum sensing (including LuxS and Agr), Cyclic di-GMP, type IV pili, and flagella. Most antibiotics recommended for the treatment of CDI do not have activity on spores and do not eliminate biofilm. Therapeutic failure in R-CDI has been associated with the inadequate concentration of drugs in the intestinal tract and the antibiotic resistance of a biofilm. This makes it challenging to eradicate C. difficile in the intestine, complicating antibacterial therapies and allowing non-eliminated spores to remain in the biofilm, increasing the risk of recurrence. In this review, we examine the role of biofilm on recurrence and the challenges of treating CDI when the bacteria form a biofilm.

Comparing fine needle biopsy techniques in solid pancreatic lesions: A prospective randomized study.

INTRODUCTION: Endoscopic ultrasound-guided fine-needle biopsies (EUS-FNB) are the best technique for sampling solid pancreatic lesions. However, the most appropriate biopsy technique has not been standardized using Fine Needle Biopsy (FNB) needles. The aim of this work was to identify the best biopsy technique to achieve the best tissue integrity and cause the least blood contamination. MATERIAL AND METHODS: Patients ≥18 years of age with solid pancreatic lesions who underwent EUS-FNB at our institution from January 2020 to May 2021 were consecutively selected. Three passes were performed with each of the threee techniques to obtain tissue: suction with 10 ml of vacuum, capillary, and wet. An independent pathologist evaluated the received tissue integrity and the degree of blood contamination of each sample according to scales. RESULTS: Seventy-five patients were recruited for our study. A superior tissue integrity was observed using the wet-suction technique in lesions located in the body and/or tail of the pancreas, and an average score of 4.40 (p = 0.027) was assigned for this technique. Regarding the contamination of the sample in the whole cohort, the simple-suction technique shown a higher contamination, 1.55 (p < 0.001). There was no statistically significant difference among the techniques when evaluating tissue integrity or contamination in lesions larger or smaller than 3 cm. CONCLUSION: When performing EUS-FNB for solid pancreatic lesions located in the head/uncinated process, the three methods provided similar diagnostic yields. The wet-suction technique had a higher score in tissue integrity when lesions were located in the body and/or tail of the pancreas.

Transcriptomic analysis of biofilm formation in strains of Clostridioides difficile associated with recurrent and non-recurrent infection reveals potential candidate markers for recurrence.

The transcriptomic profile in a biofilm model of ribotypes (RT) 001 and 027 associated with recurrent Clostridioides difficile infection (R-CDI) and not associated with recurrent (NR)-CDI was analyzed to identify genes that may favor the recurrence. Twenty strains were selected, 10 RT001 and 10 RT027. From each ribotype, 5 were R-CDI and 5 NR-CDI. Biofilm and nonadherent cells were prepared from each clinical isolate, and the RNA was extracted. RNA samples were pooled in 8 combinations implying ribotype, recurrence, and biofilm formation. Each pool was separately labeled with Cy3 dye and hybridized on a microarray designed for this study. Slides were scanned, analyzed, and gene expression was compared between unique and grouped pools using the Student's t-test with Benjamini-Hochberg correction when appropriate. Validation was carried out by qRT-PCR for selected genes. Results: After comparisons of differentially expressed genes from both ribotypes of R-CDI strains (nonadherent cells vs. biofilm) and both ribotypes in biofilm (R-CDI vs. NR-CDI), we found 3 genes over-expressed and 1 under-expressed in common (adj. p ≤ 0.05). Overexpressed genes were CAJ70148 (a putative dehydrogenase), CAJ68100 (a secretion type II system protein from the GspH (pseudopilins) family), and CAJ69725 (a putative membrane protein); under-expressed was CAJ68151 (a segregation and condensation protein A). Because CAJ70148, CAJ68100, CAJ69725 and CAJ68151 were differentially expressed in biofilm in strains associated with R-CDI, they may support the biofilm favoring the recurrence of CDI. However, further studies will be needed for poorly studied genes.

Genome Sequences of Bordetella pertussis Isolates from Outbreaks in Northeastern Mexico.

Here, we report the draft genome sequences of 4 Bordetella pertussis isolates which correspond to major clones isolated between 2008 and 2014 from two outbreaks in northeastern Mexico. The B. pertussis clinical isolates belong to the ptxP3 lineage, and they are grouped into two major clusters, defined by the fimH allele.

Primary pancreatic lymphoma: thinking beyond pancreatic adenocarcinoma.

Primary pancreatic lymphoma is one of the rare primary pancreatic tumors with a low incidence compared to adenocarcinoma, which is the most frequent. Currently there are diagnostic tools such as percutaneous biopsy and endoscopic ultrasound to reach its diagnosis. Primary lymphoma of the pancreas has defined therapeutic targets as well as a better prognosis compared to other tumors.

Body weight loss and glycemic control on the outcomes of patients with NAFLD. The role of new antidiabetic agents.

Nonalcoholic fatty liver disease (NAFLD) is currently the most common cause of chronic liver disease worldwide affecting a third of adults and 12% of children in Western countries. In around 50-60%% of cases, NAFLD and type 2 diabetes mellitus (T2DM) coexist and act synergistically to increase the risk of adverse hepatic and extra-hepatic outcomes. T2DM is a strong risk factor for rapid progression of NAFLD to nonalcoholic steatohepatitis (NASH), cirrhosis or hepatocellular carcinoma (HCC), which have become frequent indications of liver transplantation. The pathophysiology of NAFLD is complex and its relationship with T2DM is bidirectional, where lipotoxicity and insulin resistance (IR), act as the strongest pillars. To date, no pharmacological treatment has been approved for NAFLD. However, there is an intense research with numerous drugs focused on reversing inflammation and liver fibrosis through modulation of molecular targets without good results. It has been known for some time that weight reduction >10% is associated to histological improvement of NAFLD. Recently, glycemic control has been shown to induce similar results. Diet and physical exercise for weight reduction have limitations, so alternative methods (pharmacologic, endoscopic or surgical) may be required. Currently, new antidiabetic drugs inducing weight loss, have been recently approved for the treatment of obesity. Nevertheless, their therapeutic effects on NAFLD have not been extensively studied. We will review here, recently published data on the effects of weight loss and glycemic control on the histological and metabolic parameters of NAFLD and recent published data on therapeutic studies of NAFLD with new antidiabetic drugs.

Clinical, endoscopic and histological characteristics of Mexican adult patients with eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) has high prevalence/incidence in Western Europe, Canada, United States of America and Australia where it has significantly increased over the past three decades to the extent that some consider it an epidemic.

Evaluation and Validation of a New Score to Measure the Severity of Small Bowel Angiodysplasia on Video Capsule Endoscopy.

INTRODUCTION: Angiodysplasias are responsible of 50% of small bowel bleeding. An endoscopic method that allows measuring its severity is not available. AIMS: The aim of the study was to validate a new endoscopic score with VCE to measure the severity of small bowel angiodysplasias (SBAD). METHODS: Four endoscopists independently reviewed VCE videos of 22 patients with SBAD. The score graded 3 variables: A - extent of lesions: E1, located in one half of the intestine and E2, in both halves; B - number of lesions: N1, <5; N2, 5-10; and N3, >10 lesions; C - probability of bleeding: P1, pale red spots; P2, bright red spots; P3, bleeding stigmata; and P4, active bleeding. Capsule Endoscopy Small Bowel Angiodysplasia Activity Index (CESBAI) was calculated as follows: E × 1 + N × 2 + P × 3. Interobserver variability was analyzed by Spearman's correlation and agreement Kappa statistic tests. RESULTS: The mean CESBAI scores by observers were O1= 11.6 ± 4.1; O2 = 11.3 ± 4.8; O3 = 11.1 ± 4.9; and O4 = 11.8 ± 4.2 (p > 0.05). Spearman's correlation values of CESBAI between every 2 observers were from 0.61 to 0.94 (p < 0.001) with a global correlation of 0.73 among all observers. Kappa values of CESBAI between every 2 observers ranged from 0.42 to 0.87 (p < 0.001) with a global agreement of 0.57 among all observers. All evaluators stated that the method was easy to use. CONCLUSIONS: CESBAI is a reliable and reproducible score. Nevertheless, these results must be validated in other studies with larger population before assessing its power for predicting bleeding recurrence.

Diagnostic syndromic multiplex approaches for gastrointestinal infections.

Introduction: Gastrointestinal diseases due to infectious pathogens currently represent an important global health concern, especially in children and developing countries. Early and accurate detection of gastrointestinal pathogens is important to initiate the appropriate type of therapy. Multiplex molecular gastrointestinal panels rapidly detect several gastrointestinal pathogens at once with high sensitivity.Areas covered: We assess the scope and limitations of several multiplex gastrointestinal panels approved by the Food and Drug Administration or marked by Conformité Européenne-in vitro diagnostic. We compare 10 syndromic gastrointestinal panels, 14 bacteria-specific multiplex panels, seven parasite-specific multiplex panels, and eight virus-specific multiplex panels.Expert opinion: Thanks to the advances made in the diagnostic approaches for gastrointestinal infections, there are various panels to choose. The choice of a specific syndromic gastrointestinal multiplex panel should be made to improve patient care. Diagnostic syndromic multiplex approaches for gastrointestinal infections should be customized; each hospital should develop its diagnostic algorithm for gastrointestinal infections tailored to its setting, study population, and geographical site. Current multiplex gastrointestinal panels could be improved by including the detection of antimicrobial resistance, toxigenic Clostridioides difficile, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, the virus responsible for the COVID-19 pandemic).

High-Resolution Esophageal Manometry in Myasthenia Gravis.

Myasthenia gravis (MG) is an autoimmune disease that affects the postsynaptic membrane at the neuromuscular junction. In MG, antibodies bind to acetylcholine receptors inducing muscle weakness. The weakness typically increases with exercise and repetitive muscle use. Improvement of muscular weakness after rest and/or administration of anticholinesterase drugs (edrophonium) are characteristic of MG. We report a patient with unexplained dysphagia, dysphonia, and dysarthria, whose diagnosis was suggested by high-resolution esophageal motility and edrophonium infusion. We highlight the importance of dysphagia as presenting or dominant symptom in MG and review the esophageal motility findings in this rare, but treatable disorder.

Prevalence of liver fibrosis in an unselected general population with high prevalence of obesity and diabetes mellitus. Time for screening?

INTRODUCTION: Cirrhosis and liver cancer are currently common causes of death worldwide. The global epidemic of obesity has increased the incidence of nonalcoholic fatty liver disease (NAFLD) and cirrhosis in recent years. Advanced fibrosis increases the morbimortality rate in NAFLD. The Mexican population has one of the highest prevalence of obesity and diabetes mellitus (DM) worldwide. AIM: To determine the prevalence of advanced liver fibrosis in Mexican general population. METHODS: Adult individuals, without a history of liver disease nor heavy alcohol consumption were randomly sampled from 20,919 participants of a health and nutrition survey applied to the general population. Clinical and laboratory evaluations were performed to calculate the NAFLD fibrosis score (NFS) (an extensively validated non-invasive method). Two cut-off points were used. Advanced fibrosis was defined as a result >0.676. RESULTS: In total 695 individuals were included. The mean age was 47.8±16.4. The majority were between 20 and 50 years (59%), 70.2% were female, 35.5% showed obesity and 15.8% DM. The 93% had normal serum ALT. Based on the NFS results, 56 individuals (8.1%) had a high probability of fibrosis. Most patients from this subgroup showed normal serum ALT (92.9%), 89.3% were >45yr. old, 52% were obese and 27% suffered from DM. CONCLUSIONS: Based on these results, 8.1% of Mexican general population without a history of liver disease is at high risk of having advanced liver fibrosis and complications and death derived from cardiovascular disease and cirrhosis. Most of them showed normal ALT serum levels.

Diagnosis of Eosinophilic Enteritis With Video Capsule Endoscopy and Double Balloon Enteroscopy With Favorable Response to Corticosteroids.

Eosinophilic enteritis is a rare disease with nonspecific symptoms, often representing a diagnostic challenge. Video capsule endoscopy (VCE) has enabled examination of the full small bowel. However, capsule retention is an unfortunate complication. We present the case of a female patient admitted for abdominal pain. Appendectomy without resolution of symptoms was performed. A normal computed tomography and magnetic resonance imaging were obtained. The diagnosis was made by VCE and double balloon enteroscopy with biopsy. Asymptomatic capsule retention was resolved after corticosteroid therapy. The patient showed a favorable clinical and endoscopic response, confirmed through a second VCE after 3 months of treatment.

Circulation of Highly Drug-Resistant Clostridium difficile Ribotypes 027 and 001 in Two Tertiary-Care Hospitals in Mexico.

OBJECTIVE: To assess drug susceptibility and characterize Clostridium difficile ribotypes in isolates from two tertiary-care hospitals in Mexico. METHODS: Isolates were evaluated for genotyping, antimicrobial susceptibility testing and detection of mutations associated with drug resistance. PCR ribotyping was performed using a combination of gel-based and capillary electrophoresis-based approaches. RESULTS: MIC50 and MIC90 were ≥128 mg/L for ciprofloxacin, erythromycin, clindamycin, and rifampicin. There was no reduced susceptibility to metronidazole or tetracycline; however, reduced susceptibility to vancomycin (≥4 mg/L) and fidaxomicin (≥2 mg/L) was detected in 50 (40.3%) and 4 (3.2%) isolates, respectively. Furthermore, the rpoB Arg505Lys mutation was more frequently detected in isolates with high minimum inhibitory concentration (MIC) to rifampicin (≥32 mg/L) (OR = 52.5; 95% CI = 5.17-532.6; p < 0.000). Of the 124 C. difficile isolates recovered, 84 (66.7%) were of ribotype 027, 18 (14.5%) of ribotype 001, and the remainder were other ribotypes (353, 255, 220, 208, 176, 106, 076, 020, 019, 017, 014, 012, 003, and 002). CONCLUSION: Ribotypes 027 and 001 were the most frequent C. difficile isolates recovered in this study, and demonstrated higher MICs. Furthermore, we found four isolates with reduced susceptibility to fidaxomicin, raising a concern since this drug is currently unavailable in Mexican Hospitals.

Risk factors and molecular mechanisms associated with trimethoprim-sulfamethoxazole resistance in Stenotrophomonas maltophilia in Mexico.

PURPOSE: Stenotrophomonas maltophilia is a multidrug-resistant opportunistic pathogen causing an increasing number of nosocomial infections. Our aim was to evaluate the risk factors and mechanisms associated with trimethoprim-sulfamethoxazole (SXT) resistance in S. maltophilia infections in Mexico. METHODOLOGY: Clinical isolates and patients' demographic and clinical data were collected from February 2007 to August 2015 in two tertiary-care hospitals in Mexico. Antimicrobial susceptibility and analysis of sul and SmeABC and SmeDEF efflux pump overexpression were performed in all isolates.Results/Key findings. In the 9-year period, 196 patients infected with S. maltophilia were identified. Most patients were male, and the mean age was 46.2 years. The mean Charlson score was 1.42, and the most frequent comorbidities were arterial hypertension (26.7 %), type 2 diabetes (21.2 %) and cerebral infarction (11.6 %). High drug resistance to meropenem (93.4 %), gentamicin (55.1 %), ceftazidime (52.3 %), cefotaxime (51.5 %), amikacin (42.3 %) and cefepime (32.1 %), and lower resistance to ciprofloxacin (26.0 %), SXT (25.0 %), chloramphenicol (14.3 %) and levofloxacin (2.6 %) were detected. SXT resistance was not associated with the sul genes. SmeABC overexpression was associated with gentamicin (P=0.001) and levofloxacin resistance (P=0.041), whereas SmeDEF overexpression was associated with ceftazidime resistance (P=0.003). Prolonged hospitalization (≥15 days) was an independent risk factor for SXT-resistant S. maltophilia infections (OR=3.05; 95 % CI=1.12-8.86; P=0.029). CONCLUSION: Given the high SXT resistance rate, SXT is not an effective first-line therapy for our patients; instead, levofloxacin could be used as an appropriate therapeutic option against S. maltophilia infections.

Current knowledge on the laboratory diagnosis of Clostridium difficile infection.

Clostridium difficile (C. difficile) is a spore-forming, toxin-producing, gram-positive anaerobic bacterium that is the principal etiologic agent of antibiotic-associated diarrhea. Infection with C. difficile (CDI) is characterized by diarrhea in clinical syndromes that vary from self-limited to mild or severe. Since its initial recognition as the causative agent of pseudomembranous colitis, C. difficile has spread around the world. CDI is one of the most common healthcare-associated infections and a significant cause of morbidity and mortality among older adult hospitalized patients. Due to extensive antibiotic usage, the number of CDIs has increased. Diagnosis of CDI is often difficult and has a substantial impact on the management of patients with the disease, mainly with regards to antibiotic management. The diagnosis of CDI is primarily based on the clinical signs and symptoms and is only confirmed by laboratory testing. Despite the high burden of CDI and the increasing interest in the disease, episodes of CDI are often misdiagnosed. The reasons for misdiagnosis are the lack of clinical suspicion or the use of inappropriate tests. The proper diagnosis of CDI reduces transmission, prevents inadequate or unnecessary treatments, and assures best antibiotic treatment. We review the options for the laboratory diagnosis of CDI within the settings of the most accepted guidelines for CDI diagnosis, treatment, and prevention of CDI.

Non-typeable Haemophilus influenzae biofilm production and severity in lower respiratory tract infections in a tertiary hospital in Mexico.

Non-typeable Haemophilus influenzae (NTHi) is a common opportunistic bacterial pathogen that primarily infects the respiratory mucosa. This study was conducted to assess clinical and microbiological data related to disease severity in patients with lower respiratory tract infections caused by NTHi in a tertiary care hospital in Mexico. NTHi isolates were subjected to serotyping, antimicrobial susceptibility evaluationand analyses of ß-lactamase production, genetic relatednessand biofilm formation. Clinical and demographic data were retrieved from patients' records. The mean age of the patients was 40.3 years; the majority (n=44, 72.1 %) were male. The main comorbidities were arterial hypertension (n=22, 36.1 %) and diabetes mellitus (n=17, 27.9 %). NTHi isolates (n=98) were recovered from tracheal aspirate (n=57, 58.2 %), sputum (n=26, 26.5 %)and bronchial aspirate (n=15, 15.3 %) specimens. Low resistance to cefotaxime (n=0, 0.0 %), rifampin (n=1, 1.1 %) and chloramphenicol (n=3, 3.2 %) and greater resistance to ampicillin (n=30, 32.3 %) and trimethoprim-sulfamethoxazole (n=49, 52.7 %) were detected. ß-Lactamase production was found in 17 (17.3 %) isolates. Isolates displayed high genetic diversity, and only 10 (10.2 %) were found to be biofilm producers. The antimicrobial susceptibility patterns of biofilm-producing and non-producing isolates did not differ. Biofilm production was associated with prolonged hospital stay (P=0.05). Lower respiratory NTHi isolates from Mexico showed low antimicrobial resistance and weak biofilm production. Younger age was correlated with lower Acute Physiology and Chronic Health Evaluation II score (moderate, P=0.07; severe, P=0.03).

Lack of compliance with consensus recommendations on the diagnosis of eosinophilic esophagitis (EoE) in published prevalence studies. A clinical and systematic review.

OBJECTIVE: According to consensus recommendations, the presence of esophageal symptoms, >15 eosinophils/high-power field and unresponsiveness to proton pump inhibitors are required for a diagnosis of eosinophilic esophagitis (EoE). Nevertheless, inconsistency in using these guidelines has been reported in recent publications. The objective of this study was to assess compliance with EoE diagnostic guidelines in published studies on EoE prevalence and to evaluate other clinical and methodological parameters. METHODS: A systematic review was conducted in articles published between 2008 and 2015 on the prevalence of EoE in unselected adults. Studies using EoE diagnostic definitions were judged to be compliant if they included all three components of the definition, partially compliant if they included two and non-compliant if they included one or none. Esophageal biopsy protocol differences and descriptions of patients' characteristics were determined. RESULTS: Among the 20 studies included, eight were performed in a hospital setting and 12 in the general population. Only 40.0% of studies were compliant, 35.0% were partially compliant and 25.0% were non-compliant with the EoE diagnostic definition guidelines. In 60.0% of the studies a proton pump inhibitor trial was not administered. Only 30.0% adhered to the recommendations in the esophageal biopsy protocol. A lack of description of the history of atopia and endoscopic characteristics was observed in many studies. CONCLUSIONS: Partial or non-compliance with the EoE diagnostic definition was observed in most of the published prevalence studies after the publication of the first consensus. The results of these studies might be interpreted taking into account this context.

Phenotypic and genotypic characterization of vancomycin-resistant Enterococcus faecium clinical isolates from two hospitals in Mexico: First detection of VanB phenotype-vanA genotype.

INTRODUCTION: Enterococcus faecium has emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. Our aim was to determine the antimicrobial susceptibility, biofilm production, and clonal relatedness of vancomycin-resistant E. faecium (VREF) clinical isolates from two hospitals in Mexico. METHODS: Consecutive clinical isolates (n=56) were collected in two tertiary care hospitals in Mexico from 2011 to 2014. VREF isolates were characterized by phenotypic and molecular methods including pulsed-field gel electrophoresis (PFGE). RESULTS: VREF isolates were highly resistant to vancomycin, erythromycin, norfloxacin, high-level streptomycin, and teicoplanin, and showed lower resistance to tetracycline, nitrofurantoin and quinupristin-dalfopristin. None of the isolates were resistant to linezolid. The vanA gene was detected in all isolates. Two VanB phenotype-vanA genotype isolates, highly resistant to vancomycin and susceptible to teicoplanin, were detected. Furthermore, 17.9% of the isolates were classified as biofilm producers, and the espfm gene was found in 98.2% of the isolates. A total of 37 distinct PFGE patterns and 6 clones (25% of the isolates as clone A, 5.4% as clone B, and 3.6% each as clone C, D, E, and F) were detected. Clone A was detected in 5 different wards of the same hospital during 14 months of surveillance. CONCLUSION: The high resistance to most antimicrobial agents and the moderate cross-transmission of VREF detected accentuates the need for continuous surveillance of E. faecium in the hospital setting. This is also the first reported incidence of the E. faecium VanB phenotype-vanA genotype in the Americas.

A review of Helicobacter pylori diagnosis, treatment, and methods to detect eradication.

Helicobacter pylori (H. pylori) affects nearly half of the world's population and, thus, is one of the most frequent and persistent bacterial infections worldwide. H. pylori is associated with peptic ulcer disease, gastric ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Various diagnostic methods exist to detect infection, and the choice of one method or another depends on several factors, such as accessibility, advantages and disadvantages of each method, cost, and the age of patients. Once H. pylori infection is diagnosed, the clinician decides whether treatment is necessity, according to the patient's clinical condition. Typically, eradication of H. pylori is recommended for treatment and prevention of the infection. Cure rates with the standard triple therapy are acceptable, and effective quadruple therapies, sequential therapies, and concomitant therapies have been introduced as key alternatives to treat H. pylori infection. In this work, we review the main diagnostic methods used to identify H. pylori infection and to confirm eradication of infection. In addition, key factors related to treatment are reviewed.