Quantitative detection of Helicobacter pylori in water samples by real-time PCR amplification of the cag pathogenicity island gene, cagE

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.

Effects of ozone and chlorine disinfection on VBNC Helicobacter pylori by molecular techniques and FESEM images

Helicobacter pylori is a pathogen bacteria associated with chronic gastritis, peptic ulceration, and gastric carcinoma. H. pylori has a spiral morphology, which under certain conditions of stress becomes a coccoid form. This type of morphology has been linked to a viable but non-culturable (VBNC) state, which is thought to allow its persistence in the environment. Membrane damage in VBNC H. pylori in water as a mechanism for inactivation using ozone (O₃) and chlorine disinfection has not been reported in the literature. In this paper, disinfection assays with ozone and chlorine were conducted to evaluate their effects on VBNC H. pylori cells. The use of fluorescent dyes such as propidium monoazide (PMA) coupled with quantitative real-time polymerase chain reactions produced results necessary to assess the viability of the microorganism and demonstrate the effect of each disinfectant on the bacterial count. Applying ozone showed a 5-log bacterial reduction using a disinfectant concentration and exposure time (CT) of 4 mg min/L. Chlorine disinfection for the same 5-log reduction required a higher CT value. Field emission scanning electron microscope images of ozone-treated VBNC H. pylori also showed severe cell damage. The use of PMA revealed that chlorine produced physical damage in the membrane in addition to the known inhibiting effect on cell enzymatic processes. These findings are important for the detection and control of VBNC H. pylori cells in drinking water systems.

Biofilm and Helicobacter pylori: From environment to human host

Helicobacter pylori (H. pylori) is a Gram negative pathogen that selectively colonizes the human gastric epithelium. Over 50% of the world population is infected with H. pylori reaching up to 90% of infected individuals in developing countries. Nonetheless the increased impact upon public health care, its reservoir and the transmission pathway of the species has not been clearly established yet. Molecular studies allowed the detection of H. pylori in various aquatic environments, even forming biofilm in tap water distribution systems in several countries, suggesting a role of water as a possible reservoir of the pathogen. The persistence of human infection with H. pylori and the resistance of clinical isolates to commonly used antibiotics in eradication therapy have been related to the genetic variability of the species and its ability to develop biofilm, demonstrated both in vivo and in vitro experiments. Thus, during the last years, experimental work with this pathogen has been focused in the search for biofilm inhibitors and biofilm destabilizing agents. However, only two anti- H. pylori biofilm disrupting agents have been successfully used: Curcumin - a natural dye - and N-acetyl cysteine - a mucolytic agent used in respiratory diseases. The main goal of this review was to discuss the evidences available in the literature supporting the ability of H. pylori to form biofilm upon various surfaces in aquatic environments, both in vivo and in vitro. The results published and our own observations suggest that the ability of H. pylori to form biofilm may be important for surviving under stress conditions or in the spread of the infection among humans, mainly through natural water sources and water distribution systems.

Helicobacter pylori infection of the larynx may be an emerging risk factor for laryngeal squamous cell carcinoma

INTRODUCTION

Several studies have implicated Helicobacter pylori as a risk factor in laryngeal cancer, but other studies disagree. It is fundamental that the relationship between Helicobacter pylori and laryngeal cancer be verified in order to provide evidence of ways to prevent the initiation and development of this carcinoma.

MATERIALS AND METHODS

In total, 81 patients with laryngeal squamous cell carcinoma and 75 control subjects were enrolled in a case-control study. Semi-nested polymerase chain reaction techniques were applied to detect Helicobacter pylori in the laryngeal mucosa and enzyme-linked immunosorbent assays were used to detect serum antibodies against Helicobacter pylori. Risk factors associated with laryngeal carcinoma were analyzed using logistic regression models.

RESULTS

The presence of Helicobacter pylori in the larynx was higher in patients with laryngeal cancer than in control subjects (71.6 vs. 25.3 %, p < 0.001). Among patients with laryngeal carcinoma, rates of Helicobacter pylori infection were higher in normal laryngeal tissues than in tumor tissues. After adjusting for confounding factors, regression analysis indicated that the microbe was an independent risk factor for laryngeal cancer (OR = 7.15, 95 % CI [3.29, 15.53], p < 0.001).

CONCLUSIONS

This study suggests that Helicobacter pylori is present in the mucosa of the larynx. The microorganism may be an independent risk factor for laryngeal squamous cell carcinoma. The laryngeal mucosa thus provides a reservoir for the bacteria possibly, and is a likely staging place for its transmission to other areas.

Temporal study of Helicobacter pylori presence in coastal freshwater, estuary and marine waters

Helicobacter pylori, a gastric pathogen, is believed to be transmitted via the fecal-oral route as well as the oral-oral route. Its presence and viability in environmental waters is not well characterized. The goals of this study were to test H. pylori presence via molecular methods in freshwater, estuarine and beach sites in Delaware over both short and long time scales and to establish whether fecal indicator bacteria, including total Enterococcus and human-specific Bacteroidetes species, are predictive of the pathogen in these waters. The presence of Helicobacter pylori was initially tested by PCR with newly designed 23S rRNA gene primers against Helicobacter spp. and confirmed by sequencing. Two coastal beach sites were repeatedly positive in 2007. Clone library analysis indicated the persistence of one operational taxonomic unit (OTU) over time at one site. Detection of H. pylori was also determined by PCR assays from DNA and RNA for the 16S rRNA gene, as well as DNA for the ureA and cagA genes. Approximately 21% of the samples were positive for H. pylori 16S rRNA gene and 80% of those were also positive for H. pylori 16S rRNA, indicating that this potential pathogen is not only present in natural waters, but also probably viable. There was no correlation between the occurrence of H. pylori and fecal indicator bacteria, suggesting that standard water quality tests are ineffective in predicting the presence of this pathogen in natural waters. These results demonstrate the widespread presence of potentially viable H. pylori in coastal marine and estuarine waters. Additionally, the repeatedly positive samples indicate either a continual contamination source or persistence of H. pylori in marine waters.