Helicobacter pylori in water sources: a global environmental health concern

Genetic determinants of Biofilm formation of Helicobacter pylori using whole-genome sequencing

BACKGROUND

Infection with Helicobacter pylori as the cause of gastric cancer is a global public health concern. In addition to protecting germs from antibiotics, biofilms reduce the efficacy of H. pylori eradication therapy. The nucleotide polymorphisms (SNPs) related with the biofilm forming phenotype of Helicobacter pylori were studied.

RESULTS

Fifty-six H. pylori isolate from Bangladeshi patients were included in this cross-sectional study. Crystal violet assay was used to quantify biofilm amount, and the strains were classified into high- and low-biofilm formers As a result, strains were classified as 19.6% high- and 81.4% low-biofilm formers. These phenotypes were not related to specific clades in the phylogenetic analysis. The accessories genes associated with biofilm from whole-genome sequences were extracted and analysed, and SNPs among the previously reported biofilm-related genes were analysed. Biofilm formation was significantly associated with SNPs of alpA, alpB, cagE, cgt, csd4, csd5, futB, gluP, homD, and murF (P < 0.05). Among the SNPs reported in alpB, strains encoding the N156K, G160S, and A223V mutations were high-biofilm formers.

CONCLUSIONS

This study revealed the potential role of SNPs in biofilm formation and proposed a method to detect mutation in biofilm from whole-genome sequences.

Transmission routes and patterns of helicobacter pylori

BACKGROUND AND OBJECTIVE

Helicobacter pylori (H. pylori), a gram-negative bacterium that colonizes the stomach, can cause chronic gastritis and peptic ulcers, as well as gastric cancer as a Class I carcinogen. However, the modes of H. pylori transmission are not clear. This review aims to clarify the transmission routes and patterns of H. pylori and identify efficacious prevention measures.

METHODS

Studies of H. pylori transmission were identified using PubMed, the Web of Science, and Cochrane Central; the retrieval deadline was October 2022.

RESULTS

The transmission routes of H. pylori are discussed, focusing on the five primary transmission routes, namely fecal-oral, oral-oral, gastric-oral, anal-oral, and genital-oral. We propose that H. pylori is contracted through multiple transmission routes. Additionally, we summarize the key transmission patterns of H. pylori, including person-to-person and animal-to-human transmission, as well as foodborne and occupational exposure.

CONCLUSION

Fecal-oral appears to be the most common H. pylori transmission routes. Although the oral-oral pathway is also important, the evidence does not support that this route of transmission is universal. The gastric-oral route occurs primarily in children and patients who are prone to vomiting. Meanwhile, the anal-oral and genital-oral routes remain hypothetical. Person-to-person and foodborne infections represent the predominant transmission patterns of H. pylori, whereas strong environmental and occupational limitations are associated with animal-to-human and occupational exposure.

Infections with Helicobacter pylori and challenges encountered in Africa

Helicobacter pylori (H. pylori) is the causative agent of gastritis, peptic ulcer disease, mucosa associated lymphoid tissue lymphoma and gastric cancer (GC). While this bacterium infects 50% of the world’s population, in Africa its prevalence reach as high as 80% as the infection is acquired during childhood. Risk factors for H. pylori acquisition have been reported to be mainly due to overcrowding, to have infected siblings or parent and to unsafe water sources. Despite this high H. pylori prevalence there still does not exist an African guideline, equivalent to the Maastricht V/Florence Consensus Report of the European Helicobacter and Microbiota Study Group for the management of this infection. In this continent, although there is a paucity of epidemiologic data, a contrast between the high prevalence of H. pylori infection and the low incidence of GC has been reported. This phenomenon is the so-called “African Enigma” and it has been hypothesized that it could be explained by environmental, dietary and genetic factors. A heterogeneity of data both on diagnosis and on therapy have been published. In this context, it is evident that in several African countries the increasing rate of bacterial resistance, mainly to metronidazole and clarithromycin, requires continental guidelines to recommend the appropriate management of H. pylori. The aim of this manuscript is to review current literature on H. pylori infection in Africa, in terms of prevalence, risk factors, impact on human health, treatment and challenges encountered so as to proffer possible solutions to reduce H. pylori transmission in this continent.

Monitoring levels of viable Helicobacter pylori in surface water by qPCR in Northeast Spain

Helicobacter pylori infection is a risk factor for chronic active gastritis, peptic ulcers, gastric carcinoma and lymphoma. Although the infection may be acquired through different transmission routes, the presence and viability of H. pylori in water sources are not well known. Therefore, the aim of our study was to analyse the viability of H. pylori cells in urban surface waters collected at the Vallparadís public park in Terrassa, Barcelona, Spain. The water samples were analysed by viability quantitative polymerase chain reaction (qPCR) using propidium monoazide and specific primers for the H. pylori vacuolating cytotoxin (vacA gene). Viable H. pylori were found in 91.3% of the samples analysed, with an average concentration of 3.46 ± 1.06 log cell 100 mL^-1. Our work proves a quick and simple procedure for evaluating viable H. pylori cells in environmental samples by qPCR. Furthermore, the results provide evidence that urban surface waters may contain considerable levels of viable H. pylori cells, thus indicating they are a potential source of infection, which represents a public health concern.

IVTH BRAZILIAN CONSENSUS CONFERENCE ON HELICOBACTER PYLORI INFECTION

ABSTRACT Significant progress has been obtained since the III Brazilian Consensus Conference on H. pylori infection held in 2012, in Bento Gonçalves, Brazil, and justify a fourth meeting to establish updated guidelines on the current management of H. pylori infection. Therefore, the Núcleo Brasileiro para Estudo do Helicobacter pylori e Microbiota (NBEHPM), association linked to Brazilian Federation of Gastroenterology (FBG) held its fourth meeting again in Bento Gonçalves, RS, Brazil, on August 25-27, 2017. Twenty-six delegates, including gastroenterologists, endoscopists, and pathologists from the five regions of Brazil as well as one international guest from the United States, participated in the meeting. The participants were invited based on their knowledge and contribution to the study of H. pylori infection. The meeting sought to review different aspects of treatment for infection; establish a correlation between infection, dyspepsia, intestinal microbiota changes, and other disorders with a special emphasis on gastric cancer; and reassess the epidemiological and diagnostic aspects of H. pylori infection. Participants were allocated into four groups as follows: 1) Epidemiology and Diagnosis, 2) Dyspepsia, intestinal microbiota and other afections, 3) Gastric Cancer, and, 4) Treatment. Before the consensus meeting, participants received a topic to be discussed and prepared a document containing a recent literature review and statements that should be discussed and eventually modified during the face-to-face meeting. All statements were evaluated in two rounds of voting. Initially, each participant discussed the document and statements with his group for possible modifications and voting. Subsequently, during a second voting in a plenary session in the presence of all participants, the statements were voted upon and eventually modified. The participants could vote using five alternatives: 1) strongly agree; 2) partially agree; 3) undecided; 4) disagree; and 5) strongly disagree. The adopted consensus index was that 80% of the participants responded that they strongly or partially agreed with each statement. The recommendations reported are intended to provide the most current and relevant evidences to management of H. pylori infection in adult population in Brazil.

VacA, cagA, iceA and oipA genotypes status and antimicrobial resistance properties of Helicobacter pylori isolated from various types of ready to eat foods

BACKGROUND

Despite the high clinical standing of Helicobacter pylori, its exact routes of transmission and origin have not been determined. Based on the contentious hypothesis, foods play an important roles in the transmission of H. pylori to humans. The present study was carried out to investigate the vacA, cagA, oipA and iceA genotypes status of H. pylori isolated from the various types of ready to eat foods.

METHODS

A total of 550 ready to eat food samples were cultured and tested. H. pylori-positive strains were analyzed for the presence of various genotypes and antimicrobial resistance pattern.

RESULTS

Seventy four out of 550 (13.45 %) samples were positive for H. pylori. Olvie salad (36 %), restaurant salad (30 %), fruit salad (28 %) and soup (22 %) were the most commonly contaminated. H. pylori strains harbored the highest levels of resistance against amoxicillin (94.59 %), ampicillin (93.24 %), metronidazole (89.18 %) and tetracycline (72.97 %). The most commonly detected genotypes were vacA s1a (78.37 %), vacA m2 (75.67 %), vacA m1a (51.35 %) and cagA (41.89 %). The prevalence of iceA1, iceA2 and oipA genotypes were 13.51, 4.05 and 18.91 %, respectively. S1am2 (70.27 %), s1am1a (39.18 %) and m1am2 (31.08 %) were the most commonly detected combined genotypes. Of 40 different genotypic combinations, s1a/cagA+/iceA1/oipA- (12.16 %), s1a/cagA+/iceA1/oipA+ (10.81 %) and s1a/cagA-/iceA1/oipA+ (10.81 %) were the most prevalent.

CONCLUSIONS

The present investigation showed that some types of ready to eat food samples maybe the sources of resistant and virulent strains of H. pylori. Warily use of antibiotics with respect to the results of disk diffusion method and careful health monitoring on food and staffs of food producing companies maybe reduce the risk of H. pylori in foods.

Risk Factors and Prevalence of Helicobacter pylori in Five Largest Islands of Indonesia: A Preliminary Study

The prevalence of Helicobacter pylori infection in Indonesia is still controversial and mainly investigated in the largest ethnic group, Javanese. We examined the prevalence of H. pylori infection using four different tests including culture, histology confirmed by immunohistochemistry and rapid urease test. We also analyzed risk factors associated with H. pylori infection in five largest islands in Indonesia. From January 2014–February 2015 we consecutively recruited a total of 267 patients with dyspeptic symptoms in Java, Papua, Sulawesi, Borneo and Sumatera Island. Overall, the prevalence of H. pylori infection was 22.1% (59/267). Papuan, Batak and Buginese ethnics had higher risk for H. pylori infection than Javanese, Dayak and Chinese ethnics (OR = 30.57, 6.31, 4.95; OR = 28.39, 5.81, 4.61 and OR = 23.23, 4.76, 3.77, respectively, P <0.05). The sensitivity and specificity for RUT and culture were 90.2%, 92.9% and 80.5%, 98.2%, respectively. The patients aged 50–59 years group had significantly higher H. pylori infection than 30–39 years group (OR 2.98, P = 0.05). Protestant had significantly higher H. pylori infection rate than that among Catholic (OR 4.42, P = 0.008). It was also significantly lower among peoples who used tap water as source of drinking water than from Wells/river (OR 9.67, P = 0.03). However only ethnics as become independent risk factors for H. pylori infection. Although we confirmed low prevalence of H. pylori in Javanese; predominant ethnic in Indonesia, several ethnic groups had higher risk of H. pylori infection. The age, religion and water source may implicate as a risk factor for H. pylori infection in Indonesia.

Molecular Epidemiology of Helicobacter pylori Infection in Nepal: Specific Ancestor Root

Prevalence of Helicobacter pylori infection in Nepal, a low-risk country for gastric cancer, is debatable. To our knowledge, no studies have examined H. pylori virulence factors in Nepal. We determined the prevalence of H. pylori infection by using three different tests, and the genotypes of virulence factors were determined by PCR followed by sequencing. Multilocus sequence typing was used to analyze the population structure of the Nepalese strains. The prevalence of H. pylori infection in dyspeptic patients was 38.4% (56/146), and was significantly related with source of drinking water. In total, 51 strains were isolated and all were cagA-positive. Western-type-cagA (94.1%), cagA pre-EPIYA type with no deletion (92.2%), vacA s1a (74.5%), and m1c (54.9%) were the predominant genotypes. Antral mucosal atrophy levels were significantly higher in patients infected with vacA s1 than in those infected with s2 genotypes (P = 0.03). Several Nepalese strains were H. pylori recombinants with genetic features of South Asian and East Asian genotypes. These included all East-Asian-type-cagA strains, with significantly lesser activity and inflammation in the corpus than the strains of the specific South Asian genotype (P = 0.03 and P = 0.005, respectively). Although the population structure confirmed that most Nepalese strains belonged to the hpAsia2 population, some strains shared hpEurope- and Nepalese-specific components. Nepalese patients infected with strains belonging to hpEurope showed higher inflammation in the antrum than strains from the Nepalese specific population (P = 0.05). These results support that ancestor roots of Kathmandu`s people not only connected with India alone.

Clinical practice: Helicobacter pylori infection in childhood

Helicobacter pylori infection is recognised as a cause of gastritis and peptic ulcer disease (PUD) and usually acquired during the first years of life. While there is a decline in the prevalence of H. pylori infection in northern and western European countries, the infection is still common in southern and eastern parts of Europe and Asia. Symptoms of H. pylori-related PUD are nonspecific in children and may include epigastric pain, nausea and/or vomiting, anorexia, iron deficiency anaemia and hematemesis. Besides, only a small proportion of children develop symptoms and clinically relevant gastrointestinal disease. H. pylori infection can be diagnosed either by invasive tests requiring endoscopy and biopsy or non-invasive tests including the (13)C-urea breath test, detection of H. pylori antigen in stool and detection of antibodies in serum, urine and saliva. The aim of treatment is at least 90 % eradication rate of the bacteria, and a combination of two antibiotics plus a proton pump inhibitor has been recommended as first-line treatment. However, frequent use of antibiotics during childhood is associated with a decline in eradication rates and the search for new treatment strategies as well. This is an overview of the latest knowledge and evidence-based guidelines regarding clinical presentation, diagnosis and treatment of H. pylori infection in childhood.

Seroepidemiology of Helicobacter pylori infection in a Mennonite community in Durango State, Mexico

BACKGROUND

The epidemiology of Helicobacter pylori infection among Mennonites (an ethnic group of German descent living in rural communities in Mexico) has not been previously studied.

MATERIALS AND METHODS

The prevalence of anti-H. pylori IgG antibodies was examined in 152 Mennonite individuals in Durango State, Mexico, using enzyme-linked immunoassays. Seroprevalence association with sociodemographic, clinical, and behavioral characteristics of the Mennonite community was also investigated.

RESULTS

In total, 77 (50.7%) of the 152 Mennonite participants (mean age, 38.4 ± 15.5 years) had H. pylori IgG antibodies, 35 (45.4%) of whom had H. pylori IgG antibody levels higher than 100 U/mL. Males and females had comparable seroprevalence rates of H. pylori and H. pylori IgG antibody levels. On the other hand, seroprevalence of H. pylori increased significantly with age and was significantly higher among women with history of deliveries and abortions than among those with no such obstetric characteristics. Logistic regression analysis of behavioral characteristics showed that H. pylori infection was associated with a low frequency of eating at restaurants and at fast food outlets (up to 10 times/year) (OR = 2.77; 95% CI: 1.28-5.98; p = .009), and eating meat (up to 3 days/week) (OR = 2.84; 95% CI: 1.36-5.91; p = .005).

CONCLUSIONS

This is the first report on the seroprevalence of H. pylori among Mennonites, factors contributing to such infection, and the association of H. pylori infection with abortions and low frequencies of eating out of home and meat. Further research should be conducted on this topic.

Sociocultural and dietary practices among Malay subjects in the north-eastern region of Peninsular Malaysia: a region of low prevalence of Helicobacter pylori infection

BACKGROUND AND AIM

The prevalence of Helicobacter pylori infection is exceptionally low among the Malays in the north-eastern region of Peninsular Malaysia. The reasons are unknown. Our aim was to compare environmental factors that differed in relation to H. pylori prevalence among Malays born and residing in Kelantan.

METHODS

A case-control study was conducted among Malays in Kelantan who underwent upper endoscopy between 2000 and 2008. Helicobacter pylori status was determined by gastric histology. Sociocultural and dietary factors were assessed using a validated investigator-directed questionnaire administered after 2008, and the data were analyzed using logistic regression analysis.

RESULTS

The study group consisted of 161 subjects (79 H. pylori positive and 82 controls). Univariable analysis identified five poor sanitary practices associated with an increased prevalence of H. pylori infection: use of well water, use of pit latrine, less frequent boiling of drinking water, and infrequent hand wash practice after toilet use and before meals. Multivariable logistic regression analysis identified three variables inversely associated with H. pylori infection: frequent consumption of tea (OR: 0.023, 95% CI: 0.01-0.07), frequent use of "budu" or local anchovy sauce (OR: 0.09, 95% CI: 0.1-0.7), and frequent use of "pegaga" or centenella asiatica (OR: 0.25, 95% CI: 0.1-0.65).

CONCLUSIONS

Under the assumption that sanitary, sociocultural, and dietary habits have not changed over the years, we can conclude that an increased risk of H. pylori was associated with unsanitary practices whereas protection was associated with consumption of tea and locally produced foods, "pegaga" and "budu." These dietary factors are candidates for future study on the effects on H. pylori transmission.

Anti-Helicobacter pylori activity of fermented milk with lactic acid bacteria

BACKGROUND

Ten strains of lactic acid bacteria (LAB) were investigated for their anti-Helicobacter pylori effects. The bactericidal activity and organic acid content in spent culture supernatants (SCS) from fermented milk were measured. In addition, the exclusion effect of SCS against H. pylori infection of human gastric epithelial AGS cells was assayed.

RESULTS

Three LAB strains, LY1, LY5 and IF22, showed better anti-Helicobacter effects than the other strains. There were no significant differences in the bactericidal activity of LAB strains between original SCS, artificial SCS and SCS treated by heating or protease digestion. However, neutralised SCS lost this activity. These results suggest that the anti-H. pylori activity of SCS may be related to the concentration of organic acids and the pH value but not to protein components. In the AGS cell culture test, both fermented LY5-SCS and artificial LY5-SCS significantly reduced H. pylori infection and urease activity (P < 0.05).

CONCLUSION

In this study, in vitro methods were used to screen potential probiotics with anti-H. pylori activity. This may provide an excellent and rapid system for studying probiotics in the functional food and dairy industries.