Isolation and diagnosis of Helicobacter pylori by a new method: Microcapillary culture

Initial assessment of "Gissell's stain": A novel histopathological method for the identification of Helicobacter pylori

INTRODUCTION AND OBJECTIVES

The histopathological identification of Helicobacter pylori using the routine method (haematoxylin-eosin) is not only very difficult but also has low sensitivity. Giemsa staining is often used in addition, but different protocols do not produce homogeneous results. Furthermore, the Gold Standard recommended by the European Helicobacter Pylori Study Group has been applied in very few studies, thus resulting in uncertain outcomes. Therefore, a new staining method is required to overcome these limitations. The aim of this study was to evaluate the diagnostic capacity and inter-observer agreement of "Gissell's stain".

MATERIAL AND METHODS

A cross-sectional study evaluated 99 gastric paraffin blocks from a private laboratory. Three sections were prepared from each block, and haematoxylin-eosin (HE), Giemsa and "Gissell's stain" methods were applied. The kappa statistics, sensitivity, specificity, and predictive values were calculated.

RESULTS

"Gissell's stain" obtained the highest inter-observer agreement (kappa=0.87) compared to the other two methods (HE, kappa=0.51; Giemsa, kappa=0.83). It also obtained the best sensitivity and negative predictive value (97.1% and 98.3%, respectively) compared with the other two methods (HE: 68.6% and 85.1%, respectively; Giemsa: 88.6% and 93.9%, respectively).

CONCLUSIONS

Given its unique characteristics (fast, cheap, accessible, and easy to use), in addition to its statistical reliability, "Gissell's stain" has great potential for routine use in the identification of H. pylori.

Chinese Consensus Report on Family-Based Helicobacter pylori Infection Control and Management (2021 Edition)

OBJECTIVE

Helicobacter pylori infection is mostly a family-based infectious disease. To facilitate its prevention and management, a national consensus meeting was held to review current evidence and propose strategies for population-wide and family-based H. pylori infection control and management to reduce the related disease burden.

METHODS

Fifty-seven experts from 41 major universities and institutions in 20 provinces/regions of mainland China were invited to review evidence and modify statements using Delphi process and grading of recommendations assessment, development and evaluation system. The consensus level was defined as ≥80% for agreement on the proposed statements.

RESULTS

Experts discussed and modified the original 23 statements on family-based H. pylori infection transmission, control and management, and reached consensus on 16 statements. The final report consists of three parts: (1) H. pylori infection and transmission among family members, (2) prevention and management of H. pylori infection in children and elderly people within households, and (3) strategies for prevention and management of H. pylori infection for family members. In addition to the 'test-and-treat' and 'screen-and-treat' strategies, this consensus also introduced a novel third 'family-based H. pylori infection control and management' strategy to prevent its intrafamilial transmission and development of related diseases.

CONCLUSION

H. pylori is transmissible from person to person, and among family members. A family-based H. pylori prevention and eradication strategy would be a suitable approach to prevent its intra-familial transmission and related diseases. The notion and practice would be beneficial not only for Chinese residents but also valuable as a reference for other highly infected areas.

Real-time PCR detection of Helicobacter pylori clarithromycin resistance in Thrace, Greece

BACKGROUND

Growing resistance to clarithromycin is a major concern regarding treating Helicobacter pylori (H. pylori) infection. Resistance rates have a great variation even in different geographic areas within the same country and are associated with point mutations of the microbial 23S rRNA (A2142C, A2142G, and A2143G). Given the absence of available data in Thrace, the objective of this study was to estimate the resistance of H. pylori to clarithromycin and identify specific mutations that contribute to clarithromycin resistance.

METHODS

In this prospective study, we enrolled consecutive patients referred for dyspeptic complaints who underwent upper gastrointestinal endoscopy over two years. Gastric biopsies from corpus and antrum were initially tested for the presence of urease by a rapid urease test. Urease positive samples were followed by real-time PCR to confirm the presence of H. pylori and to detect point mutations.

RESULTS

A total of one hundred and thirty patients were included in the study (72 women and 58 men). Resistance to clarithromycin was detected at 23.2 %. Neither gender nor age was independently correlated with resistance rate in our patient group. The most common mutations were A2142G and A2143G.

CONCLUSIONS

A high rate of H. pylori resistance to clarithromycin was observed in our region, implicating that it should be addressed in accordance with the recommendations provided by national and international guidelines. Molecular testing should be considered an integral tool for effective monitoring in case of suspected antibiotic resistance. HIPPOKRATIA 2021, 25 (2):51-55.

First-time serological and molecular detection of Helicobacter pylori in milk from Algerian local-breed cows

AIM

The present study was conducted to detect and identify Helicobacter pylori within local cow breeds in the central region of Algeria.

MATERIALS AND METHODS

Two hundred (n=200) cows from three provinces of the central region of Algeria were studied, between January 2016 and September 2017. Each cow was subject to stool, milk, and blood sampling. Milk and fecal samples were used to detect and identify H. pylori using bacteriology culture method. Blood and milk samples were used to detect H. pylori immunoglobulin G (IgG) antibody using enzyme-linked immunosorbent assay. Polymerase chain reaction was used to confirm the abundance of H. pylori in milk by detecting glmM gene.

RESULTS

Out of 200 sera and 200 milk samples, 12% (24) and 4% (8/200) were positive for the H. pylori IgG antibody. glmM gene was detected in the milk of 13% of cows and was confirmed in all cows presenting IgG in milk.

CONCLUSION

From the present study, we concluded that the glmM gene is an important marker for detecting H. pylori in milk. Moreover, Algerian local-breed cows are a source of H. pylori and could be responsible for serious zoonosis.

Diagnosis of Helicobacter pylori Using Invasive and Noninvasive Approaches

Helicobacter pylori (H. pylori) as gram-negative and spiral microorganism is responsible for colonization in the gastric microniche for more than 50% of world population. Recent studies have shown a critical role of H. pylori in the development of peptic ulcers, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. Over the past decade, there has been a sharp interest to use noninvasive tests in diagnosis of the H. pylori infection. During the years after discovery by Marshall and Warren, it has been frequently declared that the rapid urease test (RUT) is one of the cheapest and rapid diagnostic approaches used in detecting the infection. Although the specificity and sensitivity are durable for this test, clinical experiences had shown that the ideal results are only achieved only if we take biopsies from both corpus and antrum at the same time. Given the diagnosis of the H. pylori in clinical samples, gastroenterologists are facing a long list of various molecular and nonmolecular tests. We need more in-depth researches and investigations to correctly generalize rapid and accurate molecular tests determining both bacterial identity and antibiotic resistance profile.

Hybrid Therapy versus Sequential Therapy for Eradication of Helicobacter pylori: A Randomized Controlled Trial

Objective:

To compare the sequential therapy (ST) with the hybrid therapy (HT) for the eradication of Helicobacter pylori.

Materials and Methods:

Patients with peptic ulcer disease and gastritis found to be H. pylori positive were randomized to HT group who received omeprazole (20 mg bid) and amoxicillin (1 g bid) for 7 days followed by omeprazole (20 mg bid), amoxicillin (1 g bid), clarithromycin (500 mg bid), and metronidazole (400 mg tid) for the next 7 days and ST group who received omeprazole and amoxicillin for 5 days followed by omeprazole, clarithromycin, and metronidazole for the next 5 days. Eradication rate, compliance, and complications were compared.

Results:

A total of 120 patients were included, sixty in each group. H. pylori eradication rate was significantly higher in HT group on intention-to-treat analysis (88.3% [confidence interval (CI) 78.3%–94.8%] vs. 73.3% [CI 61.1%–83.3%]; P = 0.037). Per-protocol analysis showed higher eradication rate with HT (93% [CI 83.9%–93.7%] vs. 81.5% [CI 69.5%–90.2%]; P = 0.068); however, the difference was insignificant. Compliance and side effects were similar. A complete course of HT costs $10.77, while ST costs only $6.347.

Conclusions:

HT achieves significantly higher H. pylori eradication rate than ST with comparable patient compliance and side effects but at an higher price. However, it can be used in places where ST is ineffective.

Effect of different transport conditions and media on Helicobacter pylori isolation

AIM: To optimize transport conditions and medium for Helicobacter pylori (H. pylori) isolation and culture.

METHODS: Live H. pylori bacteria were added into Broth medium with sucrose (1 g/mL) and 50% (mL/mL) calf serum and skim milk quantitatively. The bacteria in transport media were placed at different temperatures in different atmospheres for 6 hours, and then inoculated onto Columbia agar medium supplemented with 10% defibrinated sheep blood and cultured at 37 ℃ micro-aerobically for 5 d. H. pylori colonies were counted and compared. Twenty gastric mucosa specimens from patients diagnosed with gastritis or gastric ulcer were inoculated into Columbia agar and hydrolyzed casein agar supplemented with 10% defibrinated sheep blood and selective antibiotics, then incubated for 5 d at 37 ℃ micro-aerobically. Growth of H. pylori was observed and compared.

RESULTS: The number of live bacteria in calf serum medium was higher than that in skim milk. The number of live bacteria in micro-aerobic and candle jar was higher than that in air and transporting media covered with paraffin oil. The number of bacteria in calf serum media placed micro-aerobically at 37 ℃ (or 26 ℃) was higher than that at 6 ℃ (P < 0.05). There was no significant difference in the number of live bacteria when placed micro-aerobically or in candle jar (P > 0.05). The positive rate (75%) of 20 samples isolated with hydrolyzed casein blood agar was higher than that isolated with Columbia blood agar (45%) (χ² = 4.401, P < 0.05).

CONCLUSION: H. pylori clinical samples can be placed in calf serum medium in micro-aerobic conditions and transported to the laboratory for isolation. Hydrolyzed casein agar supplemented with 10% defibrinated sheep blood is better than Columbia agar medium supplemented with 10% defibrinated sheep blood for H. pylori isolation.

Helicobacter Pylori Infection: Diagnostic Strategies in Primary Diagnosis and After Therapy

Accurate diagnosis of Helicobacter pylori infection pre- and post-treatment is mandatory in the current era of decreasing prevalence and increasing antibiotic resistance. The diagnostic performance of most tests is poorer in clinical situations with low bacterial density which is seen in conditions such as atrophic gastritis or intake of antisecretory and antibiotic medications. Noninvasive tests require less cost and resource but provide excellent accuracy; however, endoscopy with testing of gastric biopsy specimens is indicated where alarming symptoms are present or antibiotic susceptibility testing by culture is desired. Newer modalities such as polymerase chain reaction testing provide additional virulence and antibiotic sensitivity profiling. This article outlines new developments and the key parameters of each test, as careful selection of test modality within the clinical context is required for adequate management of infected symptomatic patients.

Epidemiology and Diagnosis of Helicobacter pylori infection

During the period reviewed, prevalence studies were essentially performed in less economically advanced countries and a high prevalence was found. The traditional risk factors for Helicobacter pylori positivity were mostly found. Transmission studied by molecular typing showed a familial transmission. The eventual role of water transmission was explored in several studies with controversial results. Concerning diagnosis, most of the invasive and noninvasive methods used for the diagnosis of H. pylori infection are long standing with efficient performance. The most interesting recent improvements in H. pylori diagnosis include advances in endoscopy, developments in molecular methods, and the introduction of omics-based techniques. Interpretation of old or newer method should take into account the pretest probability and the prevalence of H. pylori in the population under investigation.

Diagnostic and Treatment Approaches for Refractory Peptic Ulcers

Refractory peptic ulcers are defined as ulcers that do not heal completely after 8 to 12 weeks of standard anti-secretory drug treatment. The most common causes of refractory ulcers are persistent Helicobacter pylori infection and use of nonsteroidal anti-inflammatory drugs (NSAIDs). Simultaneous use of two or more H. pylori diagnostic methods are recommended for increased sensitivity. Serologic tests may be useful for patients currently taking proton pump inhibitors (PPIs) or for suspected false negative results, as they are not affected by PPI use. NSAID use should be discontinued when possible. Platelet cyclooxygenase activity tests can confirm surreptitious use of NSAIDs or aspirin. Cigarette smoking can delay ulcer healing. Therefore, patients who smoke should be encouraged to quit. Zollinger-Ellison syndrome (ZES) is a rare but important cause of refractory gastroduodenal ulcers. Fasting plasma gastrin levels should be checked if ZES is suspected. If an ulcer is refractory despite a full course of standard PPI treatment, the dose should be doubled and administration of another type of PPI considered.