Genotyping and antimicrobial resistance patterns of Helicobacter pylori in human and dogs associated with A2142G and A2143G point mutations in clarithromycin resistance

G-protein-coupled estrogen receptor prevents nuclear factor-kappa B promoter activation by Helicobacter pylori cytotoxin-associated gene A in gastric cancer cells

Helicobacter pylori is a well-known pathogen that causes chronic gastritis, leading to the development of gastric cancer. This bacterium has also been detected in dogs, and symptoms similar to those in humans have been reported. The cytotoxin-associated gene A (CagA) is involved in pathogenesis through aberrant activation of host signal transduction, including the nuclear factor-kappa B (NF-κB) pathway. We have previously shown the anti-inflammatory effect of the G-protein-coupled estrogen receptor (GPER) via inhibiting of NF-κB activation in several cells. Therefore, here, we investigated the effect of GPER on CagA-mediated NF-κB promoter activity and showed that CagA overexpression in gastric cancer cells activated the NF-κB reporter and induced interleukin 8 (il-8) expression, both of which were inhibited by the GPER agonist.

Individualized diagnosis and eradication therapy for Helicobacter pylori infection based on gene detection of clarithromycin resistance in stool specimens: A systematic review and meta-analysis

BACKGROUND

Empiric therapy for Helicobacter pylori infection results in significantly increased antibiotic resistance and decreased eradication efficacy. The genotypic testing of clarithromycin resistance from stool specimens is a promising method for individualized diagnosis and treatment. This study aimed to determine the status of research and application on this method through a systematic review and meta-analysis.

METHODS

PubMed, Embase, MEDLINE, and WAN FANG database were searched for relevant literature. The quality of included diagnostic articles was evaluated using the quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate random-effect model was conducted to calculate the diagnostic accuracy of genotypic testing of clarithromycin resistance.

RESULTS

A total of 16 diagnostic-related were included and analyzed after exclusions. The pooled sensitivity and specificity of diagnostic meta-analysis were 0.93 (95% confidence interval [CI]: 0.90-0.96) and 0.98 (95% CI: 0.93-1.00), respectively. The area under the curve (AUC) of the summary receiver operating characteristic was 0.97 (95% CI: 0.95-0.98). The genotypic testing in stool samples had heterogeneous sensitivity (Q = 37.82, p < .01, I²  = 37.82) and specificity (Q = 60.34, p < .01, I²  = 93.72) in detecting clarithromycin resistance. Purification method, stool sample weight, real-time PCR, and antimicrobial susceptibility testing as reference accounted for the heterogeneity of pooled sensitivity, while patient age, purification method, stool sample weight, and real-time PCR for the heterogeneity of pooled specificity.

CONCLUSION

The genotypic testing of clarithromycin resistance from stool specimens is an accurate, convenient, noninvasive, and rapid detection technology, providing a definitive diagnosis of clarithromycin resistance and guiding the rational antibiotic selection.

Isolation of Multidrug-Resistant Helicobacter pylori from Wild Houseflies Musca domestica with a New Perspective for the Treatment

Background: High frequency of Helicobacter pylori infection and the unknown mode of transmission prompted us to investigate H. pylori-wild housefly relationship. H. pylori causes chronic gastritis, peptic ulcers, and stomach cancer. H. pylori persists in the gut of the experimentally infected houseflies. The existence of H. pylori strains isolated from wild houseflies, on the other hand, has never been documented. Materials and Methods: In this study, 902 wild houseflies from different sites were identified as Musca domestica, then 60 flies were screened by traditional microbiological techniques and H. pylori-specific 16S rRNA gene. The antibiotic resistance (ART) was investigated phenotypically. Wild housefly gut bacterial isolates were further evaluated genotypically to have 23S rRNA gene mutation related to clarithromycin resistance. To find efficient therapeutic alternatives, the potency of three plant extracts (garlic, ginger, and lemon) and the wasp, Vespa orientalis venom was evaluated against H. pylori. The cytotoxic effect of the crude wasp venom, the most potent extract, against Vero and Colon cancer (Caco2) cell lines was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Results: All isolates from houseflies were positive. The isolated bacteria have variable resistance to frequently used antibiotics in all isolates. Minimum inhibitory concentration values of 15.625 mg/mL for both ginger and lemon extracts, 7.8125 mg/mL for garlic extract, and 0.0313 mg/mL for wasp venom were recorded. Wasp venom has the most potent antibacterial activity compared with the four antibiotics that are currently used in therapies against H. pylori. Conclusion: We conclude that wild houseflies can play a role in disseminating H. pylori. The housefly gut may be a suitable environment for the horizontal transfer of ART genes among its associated microbiome and H. pylori. Wasp venom proved its potential activity as a new and effective anti-H. pylori drug for both therapeutic and preventative usage.

The prevalence of clarithromycin-resistant Helicobacter pylori isolates: a systematic review and meta-analysis

Background

Knowledge of global clarithromycin (CLA)-resistant rates of Helicobacter pylori (H. pylori) is crucial for decision of the most appropriate eradication therapies with good clinical outcomes. Therefore, this review and meta-analysis aimed to evaluate the global prevalence of the CLA resistance in H. pylori to provide some guidance for selecting the first-line antibiotics.

Method

A comprehensive search was performed for relevant literature until April 2021 in PubMed, Embase, and Web of Science databases. Freeman-Tukey double arcsine transformation was performed to estimate the weighted pooled prevalence of resistance.

Results

The meta-analysis included 248 articles. The prevalence of CLA-resistant H. pylori was 27.53% (95% CI [25.41-29.69]). The heterogeneity between reports was significant (I² = 97.80%, P < 0.01). The resistance rate increased from 24.28% in 2010-2017 to 32.14% in 2018-2021 (P < 0.01). Iran, with 38 articles, has the most report. Nevertheless, Switzerland, Portugal, and Israel had the highest resistance rates (67.16%, 48.11%, and 46.12%, respectively). The heterogeneity between the continents and the antimicrobial susceptibility methods also interpreted standard guidelines and breakpoints was insignificant (P > 0.05).

Conclusion

Overall CLA resistance rate was 27.53%, worldwide. The difference in CLA resistance rate among the included studies can be due to several reasons such as differences in antibiotic prescription rates in various geographic areas, use of different breakpoints or inaccurate criteria in performed studies, and the emergence of multidrug-resistant (MDR) strains.

Treatment of refractory Helicobacter pylori infection: A new challenge for clinicians

Patients who have failed two or more attempts to eradicate Helicobacter pylori are commonly referred to as refractory. Although the incidence of refractory Helicobacter pylori infection is only 10–20%, with the increasing rate of antibiotic resistance in various regions, the treatment of refractory Helicobacter pylori infection has gradually become a difficult problem faced by clinicians. When choosing a rescue therapy, the physician must consider numerous factors. A longer treatment duration, higher doses of proton pump inhibitors (PPIs), or the use of potassium-competitive acid blocker (P-CAB) may increase the efficacy of triple therapy or bismuth quadruple therapy. Rescue treatment based on bismuth quadruple therapy usually achieves better results. At the same time, treatment based on drug susceptibility tests or genotypic resistance is recommended where available. Of course, appropriate empiric treatment can also be selected according to local drug resistance, a patient’s previous medication history and compliance. It is the best choice if it can improve the success rate of the first treatment and reduce the occurrence of refractory Helicobacter pylori infection. This review aims to summarize the articles related to refractory Helicobacter pylori in recent years and to explore a better remedial treatment plan for clinicians.

Transmission of Helicobacter pylori between a human and two dogs: A case report

BACKGROUND

Whereas non-Helicobacter pylori helicobacters, which are frequently detected in the stomachs of dogs and cats as a source of zoonoses, have attracted considerable attention, the role of pets in H. pylori epidemiology is unclear. In our previous study, an H. pylori infection was detected in the stomach of a dog (Dog 1). Here, we investigated the H. pylori infection status in the female offspring of Dog 1 (Dog 2) and its owner within the same household.

MATERIALS AND METHODS

Biopsy specimens were obtained from the dog's owner and tested for H. pylori. DNA from gastric biopsy samples of Dog 1, gastric fluid sediment of Dog 2, and bacteria from the stomach of the owner was obtained, and Helicobacter genus- and species-specific PCRs were performed. Then, sequence analyses of the partial region of the ureAB gene were conducted.

RESULTS

Samples from both dogs and the owner reacted positively in the genus-specific PCR and negative in the Helicobacter felis-, Helicobacter bizzozeronii-, and Helicobacter heilmannii sensu stricto-specific PCRs. All three samples also reacted positively in the H. pylori-specific PCR. Sequences of the partial ureAB gene from all subjects were identical.

CONCLUSIONS

The results suggested that the two dogs and their owner were infected with an identical H. pylori strain. This report is the first to demonstrate that H. pylori can be transmitted between humans and dogs. Further studies are required to investigate the risk factors for the transmission of H. pylori between humans and dogs from the perspective of preventive epidemiology.

Prevalence of Helicobacter pylori among residents and their environments in the Nara prefecture, Japan

BACKGROUND

Chronic infection with Helicobacter pylori, specifically cagA-positive strains, is associated with gastric cancer. Thus, measures to prevent H. pylori infection are required. This study was conducted to clarify the prevalence of H. pylori in the community to identify the infection source and comprehensively assess the risk of H. pylori infection.

METHODS

We collected 90 human faecal samples and 73 environmental samples (water, vegetable, and animal faecal samples) from the residents in an area with a high incidence of gastric cancer in Japan. Polymerase chain reaction assay was performed to detect the glmM housekeeping gene and the cagA virulence gene of H. pylori. A questionnaire survey was conducted, and the responses were analyzed statistically.

RESULTS

The glmM gene was detected in 18 of 90 (20%) faecal samples obtained from residents; among them, the cagA gene was detected in 33.3% (6/18), and in all who had undergone eradication therapy. H. pylori was not detected in environmental samples. However, contact with dogs (OR 3.89, 95% CI 1.15-13.15, P < 0.05) was associated with higher odds for glmM gene positivity in the questionnaire survey.

CONCLUSIONS

The prevalence of H. pylori and cagA-positive strains among the residents was low. However, the study results suggest a correlation between recurrent infection and cagA-positive H. pylori strains. Although H. pylori genes were not detected in living environments, an association between contact with dogs and a glmM positive status was revealed. Further investigations targeting community-dwelling healthy people and their living environments would be required for H. pylori infection control.

Occurrence of cagA+ vacA s1a m1 i1 Helicobacter pylori in farm animals in Egypt and ability to survive in experimentally contaminated UHT milk

Cases of human gastric cancer due to Helicobacter pylori have been reported worldwide and animals might act as a reservoir of infection in certain circumstances. The recent few decades showed a rapid decline in the incidence of gastric cancer, which was mainly due to the decrease in H. pylori infection. The aims of the present study were to determine the prevalence of H. pylori among livestock and investigate whether the animal isolates can be transmitted through contaminated milk causing gastric infection. Feces and milk samples were collected from apparently healthy cows, buffaloes, and sheep, and were examined by nested PCR and genotyping. The PCR positive samples were further subjected to bacterial culture followed by partial 16s sequencing of the isolates. Twenty-nine percent of the animals showed the presence of H. pylori, mainly the virulent cagA+vacA+s1a m1 i1 genotype, which is known to be associated with serious diseases in humans. The spiral viable culturable form (SVCF) of this strain was inoculated into UHT (ultra-high temperature) milk and remained viable for up to 10 days at 4 °C. Increasing period of storage and or temperature led to a decrease in the number of the SVCF and occurrence of the coccoid viable non-culturable form (CVNCF). The infectivity of the survived forms was determined by feeding healthy groups of laboratory mice with the contaminated UHT milk containing SVCF or CVNCF for 40 days. The gastric mucosa of the two mice groups showed similar levels of H. pylori load. This highlights that H. pylori can persist in contaminated milk by entering a non-culturable state, which can induce gastric infection.