quantitative-polymerase-chain-reaction-qpcr-based-rapid-diagnosis

Quantitative Polymerase Chain Reaction (qPCR)-Based Rapid Diagnosis of <em>Helicobacter pylori</em> Infection and Antibiotic Resistance

Helicobacter pylori is a major human pathogen that&#160;infects approximately half of the global population and is becoming a serious health threat due to ...

Shenzhen university

The University of Western Australia

Zhengzhou University

Fifth Affiliated Hospital of Zhengzhou University

The genome of the human gastric pathogen Helicobacter pylori encodes a large number of DNA methyltransferases (MTases), some of which are shared among many strains, and others of which are unique to a given strain. The MTases have potential roles in the survival of the bacterium. In this study, we sequenced a Malaysian H. pylori clinical strain, designated UM032, by using a combination of PacBio Single Molecule, Real-Time (SMRT) and Illumina MiSeq next generation sequencing platforms, and used the SMRT data to characterize the set of methylated bases (the methylome).

The complete methylome of Helicobacter pylori UM032.

Recent structural analysis of the lipopolysaccharide (LPS) isolated from  G27 wild-type and -antigen ligase mutant resulted in the redefinition of the core-oligosaccharide and -antigen domains. The short core-oligosaccharide (Glc⁻Gal⁻Hep-III⁻Hep-II⁻Hep-I⁻KDO) and its attached trisaccharide (Trio, GlcNAc⁻Fuc⁻Hep) appear to be highly conserved structures among  strains. The G27 LPS contains a linear glucan⁻heptan linker between the core-Trio and distal Lewis antigens. This linker domain was commonly identified in Western strains. In contrast, out of 12 partial LPS structures of Asian strains, none displayed the heptan moiety, despite the presence of Lewis antigens. This raises the question of how Lewis antigens are attached to the Trio, and whether the LPS structure of Asian strains contain another linker. Of note, a riban was identified as a linker in LPS of the mouse-adapted SS1 strain, suggesting that alternative linker structures can occur. In summary, additional full structural analyses of LPS in Asian strains are required to assess the presence or absence of an alternative linker in these strains. It will also be interesting to study the glucan-heptan linker moieties in pathogenesis as  infections in Asia are usually more symptomatic than the ones presented in the Western world.

Lipopolysaccharide Structural Differences between Western and Asian  Strains.

 infection is a significant burden to the public health in China as it can lead to various gastric diseases including peptic ulcers and gastric cancer. Since most infections occurred during childhood, it is therefore necessary to understand the prevalence and risk determinants of this bacterial infection in children. Herewith, we conducted a cross-sectional study in the Kuichong Subdistrict of Shenzhen City to assess the prevalence and risk factors of  infection among children.

Prevalence and risk factors of  infection among children in Kuichong Subdistrict of Shenzhen City, China.

Drug resistance of Helicobacter pylori is a major clinical problem worldwide. The objective of the present study was to investigate the prevalence of antibiotic-resistant H. pylori in the city of Shenzhen in China, as well as to identify the genetic mutations specifically associated with drug resistance rather than unrelated phylogenetic signals.

Mutations of Helicobacter pylori RdxA are mainly related to the phylogenetic origin of the strain and not to metronidazole resistance.

While adenoma detection rate (ADR) is an important quality metric for screening colonoscopy, it remains difficult to be accessed due to the lack of integrated endoscopy and pathology databases. Hence, the use of an adenoma-to-polyp detection rate quotient and polyp detection rate (PDR) has been proposed to predict ADR. This study aimed to examine the usefulness of estimated ADR across different colonic segments in two age groups for Shenzhen people in China.

Actual and estimated adenoma detection rates: a 2-year monocentric colonoscopic screening outcome in Shenzhen, China.

The urea breath test (UBT) is widely used for diagnosing Helicobacter pylori infection. In the Shenzhen Kuichong People's Hospital, some UBT findings were contradictory to the histology outcomes, therefore this study aimed to assess and compare the diagnostic performance of both C- and C-UBT assays.

A re-testing range is recommended for C- and C-urea breath tests for Helicobacter pylori infection in China.

The prevalence of Helicobacter pylori antibiotic susceptibility in the Tibet Autonomous Region, China is not determined. This study aimed to evaluate the antibiotic resistance patterns of H. pylori isolates there.

Antibiotic resistance patterns of Helicobacter pylori strains isolated from the Tibet Autonomous Region, China.

Association of gastric atrophy or cancer with levels of serum pepsinogens, gastrin-17 and anti- IgG antibody have been extensively studied. However, the association of serum pepsinogen and gastrin-17 with  infection has not been studied in a large population.

Association of serum pepsinogens and gastrin-17 with  infection assessed by urea breath test.

The aim of this study was to evaluate the rifamycin cross-resistance in Helicobacter pylori, and whether the use of rifampicin E-test strips to screen H. pylori rifabutin resistance is appropriate.

The Inappropriateness of Using Rifampicin E-Test to Predict Rifabutin Resistance in Helicobacter pylori.

Helicobacter pylori infection is an infectious disease and thus the eradication treatment should be guided by susceptibility testing. This study aimed to assess the applicability of broth microdilution as a routine susceptibility testing method for H. pylori.

Reassessment of the Broth Microdilution Method for Susceptibility Testing of Helicobacter pylori.

Epidemiology of Helicobacter in Chinese families: a foundation for cost-effective eradication strategies?

As the reduced eradication rate of Helicobacter pylori (H. pylori), we introduced string-test and quantitative PCR (qPCR) for susceptibility-guided therapy innovatively. The practicality of the string test was evaluated.

Quantitative PCR of string-test collected gastric material: A feasible approach to detect Helicobacter pylori and its resistance against clarithromycin and levofloxacin for susceptibility-guided therapy.

Single-nucleotide polymorphisms (SNPs) in various human genes are key factors in carcinogenesis. However, whether SNPs in bacterial pathogens are similarly crucial in cancer development is unknown. Here, we analyzed 1,043 genomes of the stomach pathogen Helicobacter pylori and pinpointed a SNP in the serine protease HtrA (position serine/leucine 171) that significantly correlates with gastric cancer. Our functional studies reveal that the 171S-to-171L mutation triggers HtrA trimer formation and enhances proteolytic activity and cleavage of epithelial junction proteins occludin and tumor-suppressor E-cadherin. 171L-type HtrA, but not 171S-HtrA-possessing H. pylori, inflicts severe epithelial damage, enhances injection of oncoprotein CagA into epithelial cells, increases NF-κB-mediated inflammation and cell proliferation through nuclear accumulation of β-catenin, and promotes host DNA double-strand breaks, collectively triggering malignant changes. These findings highlight the 171S/L HtrA mutation as a unique bacterial cancer-associated SNP and as a potential biomarker for risk predictions in H. pylori infections.

Article	Year
The complete methylome of Helicobacter pylori UM032. BMC genomics\| PubMed ID: 26031894	2015
Lipopolysaccharide Structural Differences between Western and Asian Strains. Toxins\| PubMed ID: 30205541	2018
Prevalence and risk factors of infection among children in Kuichong Subdistrict of Shenzhen City, China. PeerJ\| PubMed ID: 32280567	2020
Mutations of Helicobacter pylori RdxA are mainly related to the phylogenetic origin of the strain and not to metronidazole resistance. The Journal of antimicrobial chemotherapy\| PubMed ID: 32676634	2020
Actual and estimated adenoma detection rates: a 2-year monocentric colonoscopic screening outcome in Shenzhen, China. JGH open : an open access journal of gastroenterology and hepatology\| PubMed ID: 32782960	2020
A re-testing range is recommended for C- and C-urea breath tests for Helicobacter pylori infection in China. Gut pathogens\| PubMed ID: 34118962	2021
Antibiotic resistance patterns of Helicobacter pylori strains isolated from the Tibet Autonomous Region, China. BMC microbiology\| PubMed ID: 35964011	2022
Association of serum pepsinogens and gastrin-17 with infection assessed by urea breath test. Frontiers in cellular and infection microbiology\| PubMed ID: 36051244	2022
The Inappropriateness of Using Rifampicin E-Test to Predict Rifabutin Resistance in Helicobacter pylori. The Journal of infectious diseases\| PubMed ID: 36478247	2022
Reassessment of the Broth Microdilution Method for Susceptibility Testing of Helicobacter pylori. The Journal of infectious diseases\| PubMed ID: 36478248	2022
Epidemiology of Helicobacter in Chinese families: a foundation for cost-effective eradication strategies? Gut\| PubMed ID: 36990678	2023
Quantitative PCR of string-test collected gastric material: A feasible approach to detect Helicobacter pylori and its resistance against clarithromycin and levofloxacin for susceptibility-gu... Helicobacter\| PubMed ID: 37066609	2023
A single-nucleotide polymorphism in Helicobacterpylori promotes gastric cancer development. Cell host & microbe\| PubMed ID: 37490912	2023

Barry J. Marshall

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