Detection of Helicobacter pylori in drinking water treatment plants in Bogotá, Colombia, using cultural and molecular techniques

Occurrence of Helicobacter pylori in drinking water sources and antimicrobial resistance profile in the central region of Peru

Introduction

Contamination of drinking water by Helicobacter pylori can cause serious diseases, including cancer. The determinants of the infection rate are socioeconomic status, low standard of living and overcrowding. In addition, exposure to environmental sources contaminated with feces, such as water and vegetables, is another risk factor for infection. We analyzed the occurrence of H. pylori in drinking water sources and the antimicrobial resistance profile in central Peru.

Methods

Water samples were collected from taps in four provinces of the Junín region. Previously, biofilm sampling was performed from the internal surface of the taps. The samples were cultured on modified brain heart infusion blood agar at 37 °C under microaerophilic conditions for seven days. Antibiotic sensitivity of H. pylori was determined by the Kirby Bauer diffusion method.

Results

The results revealed that pH (9.25) and turbidity (5.15 NTU) exceeded the Peruvian environmental quality standards for drinking water. The amount of free chlorine residual in the H. pylori positive water samples ranged from 0.02 to 0.12 mg/L. H. pylori was present in 2/192 tap water samples (1.04 %) and in 3/192 tap biofilm samples (1.56 %). It was observed that 100 % of H. pylori isolates from water samples from the Chilca district showed resistance to nalidixic acid and 66.67 % to both amoxicillin and chloramphenicol. Resistance to nalidixic acid of H. pylori isolates obtained from biofilm samples from taps in the El Tambo district ranged from 66.67 % to 100 %.

Conclusion

The study findings reveal that water samples and tap biofilms in the Chilca, El Tambo and Huamancaca chico districts in the Junín region harbor H. pylori. They also reveal variability in the pattern of resistance to more than one antibiotic tested from one district to another.

Origin of fecal contamination in lettuce and strawberries: From microbial indicators, molecular markers, and H. pylori

Around 2 billion people utilize a water source contaminated with fecal-origin microorganisms, used for both human consumption and irrigation of crops. In Colombia, the water from the Bogotá River is employed for irrigating agricultural products, including raw-consumption foods like strawberries and lettuce. This poses a risk to the end consumer, as these foods are marketed as fresh products ready for direct consumption without undergoing any disinfection or cooking treatment. The aim of this study was to determine the origin of fecal contamination in strawberries and lettuce irrigated with surface waters from Cundinamarca, Colombia, using non-human and human molecular markers, along with Helicobacter pylori (H. pylori). A total of 50 samples were collected, 25 of strawberries and 25 of lettuce, taken from crops, markets, and supermarkets. Microbiological indicators (bacterial and viral) were detected through cultivation techniques, and Microbial Source Tracking (MST) markers and H. pylori were detected through PCR. The results of our study demonstrate the presence of Escherichia coli (E. coli) (12.5 %), Enterococcus (≥25 %), spores and vegetative forms of Spores of sulphite-reducing Clostridia (SRC) (≥37.5 %), coliphages (≥12.5 %), and Salmonella sp. (≥12.5 %), in both strawberries and lettuce. In the different samples analyzed, molecular markers were detected to differentiate the source of fecal contamination above 12.5 % (HF187, CF128, ADO and DEN) and H. pylori between 0 % and 25 %, highlighting deficiencies in the production chain. of food, and the risks they pose to food security. Highlighting deficiencies in the food production chain and the risks they pose to food safety.

Reduction of Helicobacter pylori cells in rural water supply using slow sand filtration

Helicobacter pylori is a microorganism that infects 60% of the population and is considered the main cause of atrophic gastritis, gastric and duodenal ulcers, and gastric cancer. Different emerging pathogens have been found in drinking water and their presence is considered to be an important public health problem. For this reason, it is necessary to carry out the validation of reliable technologies for this type of pathogens and evaluate their performance. This paper reports, for the first time, H. pylori reduction in a drinking water pilot plant of two slow sand filters (SSF). Inlet water was taken from a gravel filtration system of a rural water supply in Colombia and then inoculated with viable cells of H. pylori. By determining the Genomic Units (GU) through quantitative Polymerase Chain Reaction (qPCR), the concentration of GU/sample was measured. In the inlet water amplification for SSF1 and SSF2 were 5.13 × 102 ± 4.48 × 102 and 6.59 × 102 ± 7.32 × 102, respectively, while for the treated water they were 7.0 ± 5.6 and 2.05 × 101 ± 2.9 × 101 GU/sample for SSF1 and SSF2, respectively. The SSF pilot plant reached up to 3 log reduction units of H. pylori; therefore, since there is not an H. pylori contamination indicator and its periodic monitoring is financially complicated, the SSF could guarantee the drinking water quality necessity that exists in rural areas and small municipalities in developing countries, where infection rates and prevalence of this pathogen are high.

Molecular surveillance of Helicobacter species with high prevalence from two streams with various wastewater pollution in Taiwan

Helicobacter species are potential zoonotic pathogens classified as either enterohepatic or gastric. Helicobacter infection can be transmitted through wastewater from households and livestock and through water from irrigation and streams. In this study, the distribution and source of Helicobacter species in the Donggang and Yenshui rivers, two natural water bodies with different characteristics, were analyzed. A total of 44 water samples were collected over the four seasons. The samples were subjected to Helicobacter 16 s rRNA gene PCR, followed by sequencing and comparison for identification and analysis. The detection rate of Helicobacter species in both rivers was 79.55%, with H. kayseriensis (10/35, 28.57%) being the most common species. Analysis of the environment around the sampling sites showed a high detection rate in the livestock-rich area, and the results of BLAST for species identification and comparison indicated feces as the contamination source. The area around the Donggang River was developed for animal husbandry, led to a high detection rate of Helicobacter species. Many Helicobacter species were identified to have a risk of zoonotic transmission, especially if the stream is used as a source of drinking, agricultural, or even aquacultural water. The high presence of Helicobacter species in natural water bodies suggests that wastewater treatment is an effective strategy to control pathogen spread. Therefore, investigation and monitoring of pathogens in wastewater are highly important. However, methods for the isolation and culture of Helicobacter species in natural waters have yet to be developed. Hence, future research should focus on developing such methods.

Quantification and cultivation of Helicobacter pylori (H. pylori) from various urban water environments: A comprehensive analysis of precondition methods and sample characteristics

Substantial evidence suggests that all types of water, such as drinking water, wastewater, surface water, and groundwater, can be potential sources of Helicobacter pylori (H. pylori) infection. Thus, it is critical to thoroughly investigate all possible preconditioning methods to enhance the recovery of H. pylori, improve the reproducibility of subsequent detection, and optimize the suitability for various water types and different detection purposes. In this study, we proposed and evaluated five distinct preconditioning methods for treating water samples collected from multiple urban water environments, aiming to maximize the quantitative qPCR readouts and achieve effective selective cultivation. According to the experimental results, when using the qPCR technique to examine WWTP influent, effluent, septic tank, and wetland water samples, the significance of having a preliminary cleaning step becomes more evident as it can profoundly influence qPCR detection results. In contrast, the simple, straightforward membrane filtration method could perform best when isolating and culturing H. pylori from all water samples. Upon examining the cultivation and qPCR results obtained from groundwater samples, the presence of infectious H. pylori (potentially other pathogens) in aquifers must represent a pressing environmental emergency demanding immediate attention. Furthermore, we believe groundwater can be used as a medium to reflect the H. pylori prevalence in a highly populated community due to its straightforward analytical matrix, consistent detection performance, and minimal interferences from human activities, temperature, precipitation, and other environmental fluctuations.

Helicobacter pylori virulence genotypes in Bogotá River and wastewater treatment plants in Colombia

BACKGROUND

Helicobacter pylori is a bacterium that infects 70%-80% of the population in Colombia, causing chronic gastritis in all those infected and gastric cancer in 1%-2% of those infected. In Colombia, some studies have identified the presence of vacA and cagA genes in environmental samples such as treated, surface, and wastewater, but they have not been evaluated in the Bogotá River. For this, the aim of this study was to identify the virulence genotypes of H. pylori present in samples from the Bogotá River and domestic wastewater treatment plants (WWTPs).

MATERIALS AND METHODS

A total of 75 water samples (51 from the Bogotá River and 24 from wastewater treatment plants) were collected. The presence of H. pylori DNA and its virulence genotypes was determined by polymerase chain reaction (PCR).

RESULTS

The presence of H. pylori DNA was demonstrated in 44% (33/75) of the samples, obtaining 63.6% (21/33) from the Bogotá River and 36.4% (12/33) from the WWTPs. The most prevalent H. pylori genotype was cagA (-) and vacAm1/s1/i1 being the most virulent of the vacA gene.

CONCLUSIONS

This is the first study in Colombia that determines the cagA and vacA genotypes in surface water and WWTPs, indicating the circulation of virulent genotypes in the population. The presence of this pathogen in the waters can be represent a risk to the health of the surrounding population since these waters are reused by the communities for different purposes.

Molecular characterization of Helicobacter pylori isolated from Nile Tilapia (Oreochromis niloticus) and fish handlers

BACKGROUND

Helicobacter pylori is a worldwide pathogen that affects both animals and humans with a wide environmental distribution, causing serious health problems in humans. This research has timely addressed the topic of new sources of H. pylori infection, which is currently a global issue, especially in developing countries. For this purpose, 115 Tilapia fish, 50 freshwater samples, and 88 fish-handlers' stool samples were investigated for the presence of H. pylori in Qena Governorate, Egypt. The applied techniques were antigen screening tests, culturing, and molecular methods through ureC gene amplification, and 16 S rRNA characterization.

RESULTS

Helicobacter pylori was detected in 7.83%, 14%, 4.35%, and 12% of the investigated fish and water samples by culture and PCR methods, respectively. Out of the total studied participants, 40 tested positive for H. pylori when screened by stool antigen test, of which 35 (39.77%), and 31 (35.23%) were confirmed by conventional and molecular techniques, respectively. The Fisher's exact test has shown a statistically significant correlation between H. pylori infection, sex, and age as risk factors, while the association was insignificant concerning the residence. Males contracted the infection at a higher rate than females (48.08% and 16.67%, respectively). Also, H. pylori infection rate was the highest among fish-handlers aged 36-45 years old (46.67%), followed by the 26-35 years old age group (39.53%). With regard to the residence, a higher occurrence rate was recorded in the rural (36.07%) than the urban population (33.33%). Helicobacter pylori isolates harbored the highest antimicrobial resistance against ampicillin (100%), metronidazole (95.24%), while the least antimicrobial resistance was recorded against levofloxacin (21.43%), and clarithromycin (26.20%). The phylogenetic analysis revealed a high degree of homology between the isolates selected from Tilapia fish, freshwater, and fish-handlers.

CONCLUSIONS

Our data emphasized the role that fish and freshwater play in disseminating H. pylori infection as one of the diseases that has a significant public health issue.

Frecuencia de la infección por Helicobacter pylori en pacientes que requirieron endoscopia digestiva en siete unidades de tres subregiones de Antioquia

Objetivo: determinar la frecuencia de Helicobacter pylori y la presencia de factores sociodemográficos, hábitos de vida y antecedentes personales y familiares de enfermedades gastroduodenales en pacientes que requirieron y fueron llevados a endoscopia digestiva (sintomáticos o por tamización) en siete unidades de endoscopia de tres subregiones de Antioquia. Materiales y métodos: estudio transversal realizado entre 2016 y 2018 que incluyó a 272 participantes. Los factores sociodemográficos, hábitos de vida, antecedentes personales y familiares se relacionaron con la infección por H. pylori. Se realizó estadística descriptiva y análisis bivariado para establecer la asociación entre las variables y el análisis multivariado (regresión binomial) para ajustar las razones de prevalencia de los factores asociados. Un valor p ≤ 0,05 se consideró estadísticamente significativo. Resultados: la frecuencia de infección por H. pylori fue de 55,9%, con diferencias por subregión (área metropolitana del Valle de Aburrá: 54,3%, oriente: 64% y Urabá: 79,2%). Los factores asociados a la infección por H. pylori fueron sexo masculino (razón de prevalencia ajustada [RPA] = 1,26; intervalo de confianza [IC] del 95% = 1,04-1,52), edad de 18-55 años (RPA = 1,62; IC 95% = 1,22-2,16), ausencia de agua potable (RPA = 1,40; IC 95%: 1,15-1,72) y nivel educativo inferior al universitario (RPA = 1,73; IC 95% = 1,26-2,38). Conclusión: la frecuencia de H. pylori fue mayor que en otros estudios recientes porque se emplearon diferentes pruebas diagnósticas para su detección y se demostraron diferencias en la frecuencia de la infección por región, lo cual se explica por la heterogeneidad en las poblaciones analizadas. Este estudio sugiere la necesidad de mejorar las condiciones de vida de la población para reducir la infección por H. pylori y dirigir medidas de prevención primaria de la infección especialmente en los grupos familiares, en hombres, individuos entre 18 y 55 años, sin agua potable y con un nivel educativo inferior al universitario.

Frequency and seasonality of viable Helicobacter pylori in drinking water in Dhamar Governorate, Yemen

Helicobacter pylori is an important and common bacterial pathogen in humans. The accumulated evidence of the existence of H. pylori in water from different environmental sources suggests a water-borne transmission route. This study aimed to investigate the occurrence of H. pylori in different water sources used by human populations in Dhamar Governorate, Yemen. 250 samples were randomly collected from the municipal water supply network, wells, and springs. The samples were processed, plated onto modified campy-blood agar, and incubated under microaerobic conditions for 4-10 days. Bacterial identification was based on morphological properties and biochemical tests. Bacteriological analysis showed that 9.6% and 13.2% of tap and surface water samples were contaminated with H. pylori, respectively. Despite a higher frequency in samples from rural areas, these were not significantly (p=0.068) more contaminated than the samples from urban areas. Regarding the seasonal variations of H. pylori detection, 85.71% of positive samples were detected in the late winter and spring seasons (February to May). To conclude, H. pylori transmission through water is likely to occur in Dhamar Governorate. Further prospective studies are highly recommended to provide further evidence and a clearer picture of H. pylori transmission.

Socioeconomic indices guided linear mixed-effects and meta-regression modelling of the temporal, global and regional prevalence of Helicobacter pylori in environmental waters: A class I carcinogen

Environmental waters (EW) substantially lend to the transmission of Helicobacter pylori (Hp). But the increase in Hp infections and antimicrobial resistance is often attributed to socioeconomic status. The connection between socioeconomic status and Hp prevalence in EW is however yet to be investigated. This study aimed to assess the impacts of socioeconomic indices (SI: continent, world bank region (WBR), world bank income (WBI), WHO region, Socio-demographic Index (SDI quintile), Sustainable Development Index (SuDI), and Human Development Index (HDI)) on the prevalence of Hp in EW. Hp-EW data were fitted to a generalized linear mixed-effects model and SI-guided meta-regression models with a 1000-resampling test. The worldwide prevalence of Hp in EW was 21.76% [95% confidence interval [CI]: 10.29-40.29], which declined significantly from 59.52% [43.28-74.37] in 1990-99 to 19.36% [3.99-58.09] in 2010-19 and with increasing trend in 2020-22 (33.33%, 22.66-45.43). Hp prevalence in EW was highest in North America (45.12%, 17.07-76.66), then Europe (22.38%, 5.96-56.74), South America (22.09%, 13.76-33.49), Asia (2.98%, 0.02-85.17), and Africa (2.56%, 0.00-99.99). It was negligibly different among sampling settings, WBI, and WHO regions demonstrating highest prevalence in rural location [42.62%, 3.07-94.56], HIEs [32.82%, 13.19-61.10], and AMR [39.43%, 19.92-63.01], respectively. However, HDI, sample size, and microbiological method robustly predict Hp prevalence in EW justifying 26.08%, 21.15%, and 16.44% of the true difference, respectively. In conclusion, Hp is highly prevalence in EW across regional/socioeconomic strata and thus challenged the uses of socioeconomic status as surrogate for hygienic/sanitary practices in estimating Hp infection prevalence.

Global and regional prevalence of Helicobacter pylori in drinking waters: A sustainable, human development and socio-demographic indices based meta-regression-modelling

Helicobacter pylori (Hp) transmission dynamics via drinking water (DW) has a far much higher direct and indirect public health disease burden than previously thought. This study aimed to assess the global prevalence of Hp in DW, distributions across regions and socioeconomic indices (continent, world bank income, Human Development Index (HDI), Sustainable Development Index (SuDI), Socio-Demographic Index (SDI) quintile, and WHO regions). Hp-DW related data mined from five databases until 10/12/2022 according to PRISMA standard were quality-appraised and fitted to a generalized linear mixed-effects model. Sub-group analysis and meta-regression-modelling coupled with a 1000-permutation test (_⁎) were conducted. The global prevalence of Hp in DW was 15.7% (95% confidence interval [CI]: 7.98-27.5), which varied significantly by sampling methods (Moore swabbing (61.0% [0.00-100.0]) vs. grab sampling (13.68%[6.99-25.04])) and detection technique (non-culture (21.35%[9.13-42.31]) vs. cultured-based methods (Psubgroup < 0.01)). The period 1990-99 had the highest prevalence (41.24% [0.02-99.97]). Regarding regional designations, Hp prevalence in DW was significantly different being highest in North America (61.82% [41.03-79.02]) by continents, AMR (42.66% [20.81-67.82]) by WHO group, high HDI (24.64% [10.98-46.43]) by HDI group and North America (61.90% [2.79-98.93]) by world bank region (Psubgroup < 0.01). Generally, sample preparation, SuDI grouping, and detection/confirmation techniques, have significant effects on the detection/prevalence of Hp in DW (Psubgroup < 0.01). Hp prevalence in DW was not significantly different among rural and urban DW (Psubgroup = 0.90), world bank income groups (Psubgroup = 0.15), and SDI quintiles (Psubgroup = 0.07). Among the predictors examined, only sample size (p < 0.1, R_∗²(coefficient of determinant) = 15.29%), continent (p_∗val = 0.04), HDI (p_∗val = 0.02), HDI group (p_∗val = 0.05), and microbiological methods (p < 0.1; R_∗²=28.09 %) predicted Hp prevalence in DW robustly. In conclusion, Hp prevalence is still endemic in DW regardless of the regional designations/improve DW supplies.

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.

Helicobacter pylori results in lysis and death after exposure to water

BACKGROUND

Helicobacter pylori has a high infection rate, and it is possible that more than half of the world's population is infected. The route of transmission of H. pylori has not been completely elucidated yet. The coccoid form of H. pylori is generally considered to be in a VBNC (viable but nonculturable) state, and this form in the environment is thought to play an important role in infection and transmission, but its stability and survivability are still unknown.

MATERIALS AND METHODS

In order to promote its changing to coccoid form, the spiral form of H. pylori grown in a culture medium was exposed to sterile distilled water, and we investigated the bacterial cell number and the morphological changes by using fluorescence staining methods and electron microscopic observation. We also examined the dynamics of its growth ability by measuring the colony forming unit on an agar-plate medium.

RESULTS

After exposure to sterile distilled water, the H. pylori spiral form rapidly lost its growth ability at 37°C. One day after exposure, approximately 95% of the spiral form disappeared and the proportion of the coccoid form increased. The total number of bacteria also decreased to less than half and continued to decrease over time. Epi-microscopic and electron microscopic observations revealed that deformation of bacterial cells, collapse, and leaking out of cell contents were promoted in exposure to sterile distilled water.

CONCLUSION

Helicobacter pylori quickly begins to transform into the coccoid form after exposure to sterile distilled water, rapidly loses its growth ability, and then lyses and dies. Water-exposure is lethal for H. pylori and it is unlikely to survive in the VBNC state in water.

Racial Differences in Helicobacter pylori Prevalence in the US: A Systematic Review

BACKGROUND AND AIMS:

Helicobacter pylori remains an important risk factor for noncardia gastric cancer and a spectrum of disease from H. pylori infection to gastric cancer. As a step toward improved clinical strategies for gastric cancer prevention, we assessed racial differences in prevalence of H. pylori from studies across the United States. This systematic review provides a comprehensive evaluation of the literature regarding racial differences in H. pylori in the United States.

METHODS:

MEDLINE, Embase, and Web of Science database searches were performed through May 26, 2021. Ultimately, 25 studies that reported H. pylori infection prevalence by race were included.

RESULTS:

All studies included in the review documented higher H. pylori prevalence in Blacks and Hispanics than in whites. The ratio of H. pylori prevalence for Blacks compared to non-Hispanic whites ranged from 1.3 to 5.4, and the ratio for Hispanics compared to non-Hispanic whites ranged from 1.8 to 4.4. Of the 5 studies that examined H. pylori CagA prevalence by race, 4 found higher prevalence among Blacks and Hispanics compared to whites, with CagA prevalence ranging from 19% to 77% in whites, 62% to 90% in Blacks, and 64% to 74% in Hispanics.

CONCLUSION:

In this review, across 25 studies, varying in underlying population, time period, and geographic location, Blacks and Hispanics appeared to have a higher prevalence of H. pylori infection than whites. This increased prevalence of H. pylori among populations also at a higher risk of gastric cancer is relevant in the clinical setting for decision-making related to H. pylori testing and gastric cancer prevention.

Epidemiology of Helicobacter pylori

In many countries alike, the time trends of gastric cancer, gastric and duodenal ulcer, ulcerative colitis, Crohn's disease, and colorectal cancer are characterized by similar birth-cohort patterns. Mortality from these diagnoses rose in cohorts born during the 19th century and then fell in subsequent cohorts born during the 20th century.

A Rapid Culture Method for the Detection of Campylobacter from Water Environments

The natural environment and water are among the sources of Campylobacter jejuni and Campylobacter coli. A limited number of protocols exist for the isolation of campylobacters in poorly filterable water. Therefore, the goal of our work was to find a more efficient method of Campylobacter isolation and detection from wastewater and surface water than the ISO standard. In the novel rapid culture method presented here, samples are centrifuged at high speed, and the resuspended pellet is inoculated on a filter, which is placed on Campylobacter selective mCCDA agar. The motile bacteria pass through the filter pores, and mCCDA agar suppresses the growth of background microbiota on behalf of campylobacters. This culture-based method is more efficient for the detection and isolation of Campylobacter jejuni and Campylobacter coli from poorly filterable water than the ISO 17995 standard. It also is less time-consuming, taking only 72 h and comprising three steps, while the ISO standard method requires five or six steps and 144-192 h. This novel culture method, based on high-speed centrifugation, bacterial motility, and selective cultivation conditions, can be used for the detection and isolation of various bacteria from water samples.

Optimization of pre- treatments with Propidium Monoazide and PEMAX™ before real-time quantitative PCR for detection and quantification of viable Helicobacter pylori cells

Accurate detection of H. pylori in different environmental and clinical samples is essential for public health strtdudies. Now, a big effort is being made to design PCR methodologies that allow for the detection of viable and viable but non-culturable (VBNC) H. pylori cells, by achieving complete exclusion of dead cells amplification signals. The use of DNA intercalating dyes has been proposed. However, its efficacy is still not well determined. In this study, we aimed to test the suitability of PMA and PEMAX™ dyes used prior to qPCR for only detecting viable cells of H. pylori. Their efficiency was evaluated with cells submitted to different disinfection treatments and confirmed by the absence of growth on culture media and by LIVE/DEAD counts. Our results indicated that an incubation period of 5 min for both, PMA and PEMAX™, did not affect viable cells. Our study also demonstrated that results obtained by using intercalating dyes may vary depending on the cell stress conditions. In all dead cell's samples, both PMA and PEMAX™ pre-qPCR treatments decreased the amplification signal (>10³ Genomic Units (GU)), although none of them allowed for its disappearance confirming that intercalating dyes, although useful for screening purposes, cannot be considered as universal viability markers. To investigate the applicability of the method specifically to detect H. pylori cells in environmental samples, PMA-qPCR was performed on samples containing the different morphological and viability states that H. pylori can acquire in environment. The optimized PMA-qPCR methodology showed to be useful to detect mostly (but not only) viable forms, regardless the morphological state of the cell.

A catchment-scale assessment of the sanitary condition of treated wastewater and river water based on fecal indicators and carbapenem-resistant Acinetobacter spp

Urbanization and population growth have created considerable sanitation challenges in cities and communities in many parts of Europe and the world. As such, it is imperative to identify the most environmentally-harmful microbiological and chemical sources of pollution, these being wastewater treatment plants (WWTPs) which release wastewater of low quality. In the present manuscript, an extensive study was performed of the sanitary conditions of river water and treated wastewater from seventeen WWTPs of various sizes along the Pilica River catchment in central Poland, with the aim of identifying "hot spots" in terms of most serious sources of sanitary hazards. The bacteriological risk for the river, including fecal indicator bacteria (FIB) such as coliforms, E.coli, enterococci, C. perfringens, and carbapenem-resistant Acinetobacter spp. (CRA) were assessed using classical microbiological methods, and the physicochemical parameters were also tested. The WWTPs, particularly the small ones (<2000 people equivalent, PE) demonstrated significant variation regarding the physicochemical parameters. Carbapenem-resistant Acinetobacter spp. bacteria growing at 42 °C were found in the effluent wastewaters of all tested municipal WWTPs, and in most of the Pilica River water samples, presenting a potential hazard to public health. A positive correlation was identified between E. coli and CRA abundance in treated wastewater; however, no such relationship was found in river water. It was found that seven small treatment plants discharged wastewater with very different microbiological parameters. Moreover, three small treatment plants serving only 0.56% of the population in the studied area continuously released extremely high microbiological contamination, constituting as much as 54-82% of fecal indicator bacteria loads in the area studied. Our findings show that this type of comprehensive analysis may enable assessment of the use of the entire catchment area, thus identifying the most serious threats to surface water quality and guiding the actions needed to improve the worst operating WWTPs.

Deep-amplicon sequencing (DAS) analysis to determine the presence of pathogenic Helicobacter species in wastewater reused for irrigation

Wastewater has become one of the most important and least expensive water for the agriculture sector, as well as an alternative to the overexploitation of water resources. However, inappropriate treatment before its reuse can result in a negative impact on the environment, such as the presence of pathogens. This poses an increased risk for environmental safety, which can subsequently lead to an increased risk for human health. Among all the emerging wastewater pathogens, bacteria of the genus Helicobacter are some of the most disturbing ones, since they are directly related to gastric illness and hepatobiliary and gastric cancer. Therefore, the aim of this study was to determine the presence of potentially pathogenic Helicobacter spp. in treated wastewater intended for irrigation. We used a next generation sequencing approach, based on Illumina sequencing in combination with culture and other molecular techniques (qPCR, FISH and DVC-FISH), to analyze 16 wastewater samples, with and without an enrichment step. By culture, one of the direct samples was positive for H. pylori. FISH and DVC-FISH techniques allowed for detecting viable Helicobacter spp., including H. pylori, in seven out of eight samples of wastewater from the tertiary effluents, while qPCR analysis yielded only three positive results. When wastewater microbiome was analyzed, Helicobacter genus was detected in 7 samples. The different molecular techniques used in the present study provided evidence, for the first time, of the presence of species belonging to the genus Helicobacter such as H. pylori, H. hepaticus, H. pullorum and H. suis in wastewater samples, even after disinfection treatment.

In vitro antimicrobial activity of immobilised essential oil components against Helicobacter pylori

Available disinfection methods and therapies against Helicobacter pylori have multiple disadvantages, such as increased prevalence of antibiotic-resistant strains, which requires the search for novel effective antimicrobial agents against H. pylori. Among them, naturally-occurring antimicrobial compounds, like essential oil components (EOCs), have been reported as substances with anti-H. pylori potential. To avoid the disadvantages associated with using EOCs in their free form, including volatility, low water solubility and intense sensory properties, their immobilisation in inert supports has recently been developed. This study sought to evaluate the inhibitory properties of EOCs immobilised on silica microparticles against H. pylori and to elucidate the mechanism of action of the immobilised antimicrobials. After the preparation and characterisation of the antimicrobial supports, the susceptibility of H. pylori in the presence of the immobilised compounds was assessed by plate count, fluorescent viability staining and direct viable count-fluorescent in situ hybridisation analyses. The antimicrobial supports were found to inhibit H. pylori growth, and to induce morphological and metabolic alterations to the H. pylori membrane, with a minimum bactericidal concentration value between 25 and 50 μg/ml according to the tested EOC. These findings indicate that immobilised EOCs can be used as potential antimicrobial agents for H. pylori clearance and treatment.

Correlation among fecal indicator bacteria and physicochemical parameters with the presence of Helicobacter pylori DNA in raw and drinking water from Bogotá, Colombia

BACKGROUND

The quality of raw and drinking water is a matter of considerable concern due to the possibility of fecal contamination. To assess the quality and public health risk of different types of water, the fecal indicator bacteria (FIB) are used. However, some pathogens, such as Helicobacter pylori, may be present in water when FIB cannot be found. H pylori is recognized as the causative agent of chronic gastritis, peptic and duodenal ulcers, and gastric cancer. The aim of this study was to evaluate the relationships among physicochemical parameters, FIB concentrations, and the presence of H pylori DNA in raw and drinking water from Bogotá, Colombia.

MATERIALS AND METHODS

A total of 310 water samples were collected 1 day per week from July 2015 to August 2016, and physicochemical parameters (pH, turbidity, conductivity, and residual free chlorine) were measured. Presence of H pylori DNA was determined and quantified by quantitative polymerase chain reaction (qPCR). Fecal indicator bacteria (total coliforms, Escherichia coli, and spores of sulfite-reducing Clostridia) were enumerated by using standard culture techniques.

RESULTS

Thirty of 155 (31%) raw water samples and forty-eight of 155 (38.7%) drinking water samples were positive for the presence of H pylori. No statistically significant relationships were found between physicochemical parameters or FIB with the presence or absence of H pylori in any sample (P < 0.05).

CONCLUSIONS

This study provides evidence of the presence of H pylori DNA in raw and drinking water in Bogotá, and shows that the detection and enumeration of FIB and physicochemical parameters in water do not correlate with the risk of contamination with H pylori.