Antibiotic resistance of Helicobacter pylori from patients in Ile-Ife, South-west, Nigeria. Afr Health Sci. 2007;7:143-147. [PMID: 18052867 DOI: 10.5555/afhs.2007.7.3.143]

Helicobacter pylori Diagnosis and Treatment in Africa: The First Lagos Consensus Statement of the African Helicobacter and Microbiota Study Group

BACKGROUND

Helicobacter pylori (H. pylori) infection is the most prevalent type of bacterial infection. Current guidelines from different regions of the world neglect specific African conditions and requirements. The African Helicobacter and Microbiota Study Group (AHMSG), founded in 2022, aimed to create an Africa-specific consensus report reflecting Africa-specific issues.

SUMMARY

Eighteen experts from nine African countries and two European delegates supported by nine African collaborators from eight other countries prepared statements on the most important African issues in four working groups: (1) epidemiology, (2) diagnosis, (3) indications and prevention, and (4) treatment. Limited resources, restricted access to medical systems, and underdeveloped diagnostic facilities differ from those of other regions. The results of the individual working groups were presented for the final consensus voting, which included all board members.

KEY MESSAGES

There is a need for further studies on H. pylori prevalence in Africa, with diagnosis hinged on specific African situation. Treatment of H. pylori in the African setting should be based on accessibility and reimbursement, while indication and prevention should be defined in specific African countries.

Colonization by Various Morphological Forms of Helicobacter pylori in the Gingival Sulcus and Antrum of the Stomach

BACKGROUND

Helicobacter pylori eradication therapy can be considered effective if the result of its implementation is removed including all roots and rootlets from which surviving H. pylori can repopulate in the gastric mucosa. One of the reasons for the ineffectiveness of eradication therapy can be the continuous presence of viable coccoid forms of H. pylori in the oral cavity. Therefore, anti-Helicobacter eradication therapy should be supplemented by the sanitation of the oral cavity.

OBJECTIVES

The objective of this study is to determine the frequency of occurrence of H. pylori in the gastric mucosa and in the oral cavity in patients with chronic periodontitis or with chronic gastritis using immunocytochemical method and to evaluate the pathophysiological relationship between periodontitis and HP-associated acid-dependent stomach diseases mediated by H. pylori.

METHODS

A group of patients with chronic gastritis (70 participants, 46 women, 24 men, age: 24 - 55 years) and another group with chronic periodontitis before the start of surgical treatment (61 participants, 30 women, 31 men, age: 20 - 60 years) were examined for НР bacterial cells using immunocytochemical methods of staining gastric biopsy and exfoliate samples from the gingival sulcus surface. The participants did not take any antimicrobial medication before and during the examination. Routine staining was also performed to view microbiota in smears for both groups. The participants signed a voluntary consent agreement to undergo routine medical examinations and join the study at the Nikiforov Russian Centre of Emergency and Radiation Medicine, EMERCOM of Russia, where the ethical committee was made.

RESULTS

Immunocytochemical method could identify all stages of bacillary-coccoid transformation of H. pylori which accounted for 63.4-67.5% of cases. HP-antigenpositive bacteria were found in the oral cavity in both groups of examined patients. It was apparent that spiral forms of H. pylori were dominant over coccoid forms in the gastric mucosa in the antrum of the stomach, whereas coccoid forms of H. pylori were frequently found more in the oral cavity. Helicobacteriosis in the oral cavity was identified in chronic periodontitis.

CONCLUSION

We found certain pathogenetic connections between inflammatory lesions of the oral cavity and diseases of the internal organs of the gastrointestinal tract. Accordingly, we suggest the necessity to use proper medication for oral cavity sanitation along with anti-Helicobacter eradication therapy to influence the HP reservoir in the oral cavity and gingival sulcus. Additionally, bacterial cells of HP reside in the oral cavity in coccoid forms; therefore, the coccoid form of HP should become the second principal target in treating HP.

Selective Targeting of Human and Animal Pathogens of the Helicobacter Genus by Flavodoxin Inhibitors: Efficacy, Synergy, Resistance and Mechanistic Studies

Antimicrobial resistant (AMR) bacteria constitute a global health concern. Helicobacter pylori is a Gram-negative bacterium that infects about half of the human population and is a major cause of peptic ulcer disease and gastric cancer. Increasing resistance to triple and quadruple H. pylori eradication therapies poses great challenges and urges the development of novel, ideally narrow spectrum, antimicrobials targeting H. pylori. Here, we describe the antimicrobial spectrum of a family of nitrobenzoxadiazol-based antimicrobials initially discovered as inhibitors of flavodoxin: an essential H. pylori protein. Two groups of inhibitors are described. One group is formed by narrow-spectrum compounds, highly specific for H. pylori, but ineffective against enterohepatic Helicobacter species and other Gram-negative or Gram-positive bacteria. The second group includes extended-spectrum antimicrobials additionally targeting Gram-positive bacteria, the Gram-negative Campylobacter jejuni, and most Helicobacter species, but not affecting other Gram-negative pathogens. To identify the binding site of the inhibitors in the flavodoxin structure, several H. pylori-flavodoxin variants have been engineered and tested using isothermal titration calorimetry. An initial study of the inhibitors capacity to generate resistances and of their synergism with antimicrobials commonly used in H. pylori eradication therapies is described. The narrow-spectrum inhibitors, which are expected to affect the microbiota less dramatically than current antimicrobial drugs, offer an opportunity to develop new and specific H. pylori eradication combinations to deal with AMR in H. pylori. On the other hand, the extended-spectrum inhibitors constitute a new family of promising antimicrobials, with a potential use against AMR Gram-positive bacterial pathogens.

Helicobacter pylori antibiotic sensitivity pattern in dyspeptic patients in Kano, Nigeria

BACKGROUND

Despite the high prevalence of Helicobacter pylori infection in Nigeria, in the North-West there are no studies on the antibiotic sensitivity pattern of this organism. This study aims to determine the antibiotic sensitivity pattern of this bacterium as well as bridge the gap in knowledge.

METHODS

The study was cross-sectional in design. Questionnaires were administered in dyspeptic patients to obtain the relevant data. Two sets of gastric biopsy specimens were taken during upper gastrointestinal (GI) endoscopy. One set was sent to the histopathology laboratory for assessment and H. pylori identification, while the other set for culture was minced and plated on Columbia blood agar media (Oxoid Ltd, England) incubated at 37°C in an anaerobic jar containing CampyGen (Oxoid Ltd) to provide the required micro-aerobic environment. The disc diffusion method was used in determining the sensitivity pattern of isolates. Pre-treatment and post-treatment stool samples were collected from each patient for a H. pylori faecal antigen test to assess eradication rate.

RESULTS

The sensitivity of H. pylori to amoxicillin was 9.2%, and 100% for both clarithromycin and levofloxacin. Tetracycline, metronidazole, cefuroxime, tinidazole and ciprofloxacin were 100% resitant. The prevalence of H. pylori at histology was 81.7%. Only 101 subjects had a positive H. pylori stool antigen test.

CONCLUSION

This study showed a high amoxicillin resistance; however, there is high sensitivity (100%) to clarithromycin and levofloxacin. We recommended that levofloxacin be adopted in preference to amoxicillin as part of triple therapy in Nigeria.

Clinical and Socio- Demographic Risk Factors for Acquisition of Helicobacter pylori Infection in Nigeria

Background: The aim of the study was to assess clinical and socio-demographic characteristics as well as prior drug usage as risk factors for Helicobacter pylori (H. pylori) infection in Nigeria. Methods: A total of 347 respondents were surveyed by assessing their clinical and socio-demographic characteristics in comparison with the non-invasive gold standard for H. pylori diagnosis, the urea breath test (UBT). Chi-square test and odds ratio analyses were conducted in order to assess if variables such as socio-demographic factors, drug intake, and history of ulcer/gastritis/ gastric cancer within the family significantly predicted test results. Results: A total of 130 (37.5%) respondents were positive for H. pylori by the UBT. Living with more than three people in an apartment and a history of ulcer/gastritis within the family were significantly associated with H. pylori (p ≤0.05), as well as current antibiotic intake (p ≤0.05). Nationality, stay outside Nigeria, level of education, main occupation, smoking and drinking habits, sources of drinking water, number of children and history of gastric cancer had no significant association with H. pylori infection (p ≥ 0.05). Conclusion: The results of the questionnaire revealed that most socio-demographic characteristics of the respondents had no significant association with H. pylori. Overcrowding, having siblings/parents with history of ulcer/gastritis as well as prior antibiotic usage had a significant association.

The magnitude of antibiotic resistance to Helicobacter pylori in Africa and identified mutations which confer resistance to antibiotics: systematic review and meta-analysis

Background

Worldwide Helicobacter pylori (H.pylori) treatment is of great challenge due to increased antibiotic resistance. The burden of H. pylori antibiotic resistance in Africa is high with unclear information regarding the real magnitude. This systematic review and meta-analysis was conducted to investigate the magnitude of H.pylori antibiotic resistance in Africa to gain insight of the extent of the problem among H.pylori naïve treatment patients.

Method

The search was performed in the academic databases, Embase, PubMed, Web of Science and Africa Wide Information. ProQuest Dissertation and Theses, Scopus, Ethos, Africa Index Medicus (WHO), BioMed Central Proceedings, BASE, British Library, Open grey, Library of Congress and the New York Academy of Grey Literature Report were additionally searched for grey literature. Published articles from Africa on H.pylori antibiotic resistance between 1986 and June 2017 were systematically reviewed to estimate the H. pylori extent of resistance to macrolides, quinolones, amoxicillin, tetracycline and metronidazole.

Results

In 26 articles a total of 2085 isolates were tested for metronidazole, 1530 for amoxicillin, 1277 for tetracycline, 1752 for clarithromycin and 823 for quinolones.The overall pooled proportion of H.pylori resistance to quinolones, clarithromycin, tetracycline, metronidazole and amoxicillin were: (17.4%, 95%CI 12.8 - 21.9), (29.2%, 95%CI:26.7-31.8), (48.7%, 95%CI: 44.5-52.9), (75.8%, 95% CI: 74.1-.77.4) and (72.6%, 95% CI: 68.6-76.6), respectively. The commonest mutation detected were A2143G (49/97) for clarithromycin, RdxA (41/56) for metronidazole and D87I (16/40) for quinolones.

Conclusion

Prevalence of metronidazole, clarithromycin, and amoxicillin resistance is high in developing world including Africa. This could impair the first line triple therapy of the H.pylori infection. There is a need of conducting surveillance of H.pylori susceptibility pattern in Africa for dual and triple resistance which can be used for the empirical treatment.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3099-4) contains supplementary material, which is available to authorized users.

Gastroprotective and gastric motility benefits of AD-lico/Healthy Gut™ Glycyrrhiza inflata extract

The aim of this study was to evaluate in vivo both the anti-Helicobacter and the gastric-relaxing effects of AD-lico/Healthy Gut™ in rat models. AD-lico/Healthy Gut™ is a specially prepared commercial formulation of Glycyrrhiza inflata extract that is under clinical development for indications of gastrointestinal disease and inflammatory bowel disease. In the current study, the oral administration of AD-lico/Healthy Gut™ significantly reduced mucosal damage from Helicobacter pylori in rats and decreased the expression of the inflammatory markers iNOS and COX-2 in the test cells. AD-lico/Healthy Gut™ also reduced mucosal damage caused by water immersion stress in rats. The accelerated gastric emptying in normal rats was also seen with AD-lico/Healthy Gut™, providing relief in gastric relaxation in the test animals. The special formulation of AD-lico/Healthy Gut™ with reduced levels of component glycyrrhizin also has benefits in minimizing the potential side effects attributed to glycyrrhizin seen with similar Glycyrrhiza extracts in terms of induction of hypokalemia and muscle weakness. The preparation has a relatively high phenolic compound content relative to other methods of preparation and is indicative of lower glycyrrhizin levels. These results suggest that AD-lico/Healthy Gut™ may provide the necessary relief from a number of stomach discomfort issues faced by a large population of people.

Helicobacter pylori strains from a Nigerian cohort show divergent antibiotic resistance rates and a uniform pathogenicity profile

Antibiotic resistance in Helicobacter pylori is a factor preventing its successful eradication. Particularly in developing countries, resistance against commonly used antibiotics is widespread. Here, we present an epidemiological study from Nigeria with 111 isolates. We analyzed the associated disease outcome, and performed a detailed characterization of these isolated strains with respect to their antibiotic susceptibility and their virulence characteristics. Furthermore, statistical analysis was performed on microbiological data as well as patient information and the results of the gastroenterological examination. We found that the variability concerning the production of virulence factors between strains was minimal, with 96.4% of isolates being CagA-positive and 92.8% producing detectable VacA levels. In addition, high frequency of bacterial resistance was observed for metronidazole (99.1%), followed by amoxicillin (33.3%), clarithromycin (14.4%) and tetracycline (4.5%). In conclusion, this study indicated that the infection rate of H. pylori infection within the cohort in the present study was surprisingly low (36.6%). Furthermore, an average gastric pathology was observed by histological grading and bacterial isolates showed a uniform pathogenicity profile while indicating divergent antibiotic resistance rates.

In Vitro and In Vivo Anti-Helicobacter Activities of Eryngium foetidum (Apiaceae), Bidens pilosa (Asteraceae), and Galinsoga ciliata (Asteraceae) against Helicobacter pylori

This study was performed to evaluate the antimicrobial activities of extracts of Bidens pilosa, Galinsoga ciliata, and Eryngium foetidum against 6 clinical strains of Helicobacter pylori in vitro and in vivo. Broth microdilution method was used in vitro. In vivo, Swiss mice were inoculated with H. pylori and divided into 5 groups; the control group received the vehicle and the four others received 125, 250, and 500 mg/kg of methanol extract of Eryngium foetidum and ciprofloxacin (500 mg/kg) for 7 days, respectively. Helicobacter pylori colonization and number of colonies in gastric biopsies culture were assessed on days 1 and 7 after treatment. The lowest MIC value (64 μg/mL) and the best spectrum of bactericidal effect (MBC/MIC = 1) were obtained with the methanol extract of Eryngium foetidum. The number of H. pylori infected animals was 17% (plant-extract) and 0% (ciprofloxacin) compared to 100% for the infected untreated group. Plant-extract (381.9 ± 239.5 CFU) and ciprofloxacin (248 ± 153.2 CFU) significantly reduced bacterial load in gastric mucosa compared to untreated, inoculated mice (14350 ± 690 CFU). Conclusion. The present data provided evidence that methanol extract of Eryngium foetidum could be a rich source of metabolites with antimicrobial activity to fight Helicobacter pylori infections.

Treatment of Helicobacter pylori infection: meeting the challenge of antimicrobial resistance

Treatment of Helicobacter pylori (H. pylori) infection is paramount for the management of prevalent gastrointestinal disorders including peptic ulcer disease and gastric cancer. Due to the wide increase in prevalence of H. pylori resistance to antibiotics, clarithromycin-based triple therapies are not any more suitable for unconditional empiric use, and should not be recommended, unless local resistance to this antibiotic is low (< 20%). Alternative strategies have been proposed to overcome the issue of increasing clarithromycin resistance, and some of them are already implemented in clinical practice. These comprise: (1) adoption of novel, more effective, empirical treatments: bismuth quadruple, sequential, non-bismuth quadruple (concomitant), dual-concomitant (hybrid), and levofloxacin-based regimens, the latter mainly designated as second-line/rescue options; (2) perspectives for a susceptibility-guided (tailored) therapeutic approach based on culture-free molecular testing methods; and (3) adjunct use of probiotics to improve eradication rates. The present article is aimed to provide a comprehensive overview of current and emerging strategies in the treatment of H. pylori infection, focusing on the challenge of antimicrobial resistance.

Lactobacillus reuteri in management of Helicobacter pylori infection in dyspeptic patients: a double-blind placebo-controlled randomized clinical trial

INTRODUCTION

The eradication rate of Helicobacter pylori following the standard triple therapy is declining. This study was conducted to test whether the addition of Lactobacillus reuteri to the standard triple therapy improves the eradication rates as well as the clinical and pathological aspects in H. pylori infection.

METHODS

A total of 70 treatment-naïve patients were randomly assigned into group A (the L. reuteri treated group) and group B (the placebo control group). Patients were treated by the standard triple therapy for 2 weeks and either L. reuteri or placebo for 4 weeks. They were examined by symptom questionnaire, H. pylori antigen in stool, upper endoscopy with biopsies for rapid urease test and histopathological examination before treatment and 4 weeks after treatment.

RESULTS

The eradication rate of H. pylori infection was 74.3% and 65.7% for both L. reuteri and placebo treated groups, respectively. There was a significant difference regarding the reported side effects, where patients treated with L. reuteri reported less diarrhea and taste disorders than placebo group. A significant difference within each group was observed after treatment regarding Gastrointestinal Symptom Rating Scale (GSRS) scores; patients treated with L. reuteri showed more improvement of gastrointestinal symptoms than the placebo treated group. The severity and activity of H. pylori associated gastritis were reduced after 4 weeks of therapy in both groups. The L. reuteri treated group showed significant improvement compared with the placebo treated group.

CONCLUSION

Triple therapy of H. pylori supplemented with L. reuteri increased eradication rate by 8.6%, improved the GSRS score, reduced the reported side effects and improved the histological features of H. pylori infection when compared with placebo-supplemented triple therapy.

Primary antibiotic resistance and associated mechanisms in Helicobacter pylori isolates from Senegalese patients

Background

Antibiotic combination therapy for Helicobacter pylori eradication must be adapted to local resistance patterns, but the epidemiology of H. pylori resistance to antibiotics is poorly documented in Africa. The aim was to determine the antibiotic resistance rates, as well as the associated molecular mechanisms, of strains isolated in Dakar, Senegal.

Methods

One hundred and eight H. pylori strains were isolated between 2007 and 2009 from 108 patients presenting with upper abdominal pain to the Gastroenterology Department of Le Dantec Hospital. Antimicrobial susceptibility testing was performed for amoxicillin, clarithromycin, metronidazole, levofloxacin and tetracyclin using the E-test method. Mutations in the 23S rRNA gene of clarithromycin-resistant strains and in gyrA and gyrB of levofloxacin-resistant strains were investigated.

Results

Isolates were characterized by no resistance to amoxicillin (0%), tetracycline (0%), and very low rate of resistance to clarithromycin (1%), but a high rate of resistance to metronidazole (85%). The clarithromycin-resistant strain displayed the A2143G mutation. A worrying rate of levofloxacin resistance was detected (15%). N87I and D91N were the most common mutations in the quinolone-resistance-determining region of gyrA.

Conclusions

The first-line empirical regimen for H. pylori eradication in Senegal should include clarithromycin. Increasing rates of fluoroquinolone resistance detected should discourage the use of levofloxacin-containing regimens without prior antimicrobial susceptibility testing.

Antimicrobial susceptibility of Helicobacter pylori strains isolated from patients in Shiraz, Southern Iran

AIM: To improve our understanding of Iranian regional variation in Helicobacter pylori (H. pylori) antibiotic resistance rates to find the best antibiotic therapy for eradication of H. pylori infections.

METHODS: A total of 266 patients undergoing endoscopy in Shiraz, Southern Iran, were included in this study. H. pylori strains were isolated from antral biopsies by culture and confirmed by the rapid urease-test and gram staining. Antibiotic susceptibility of H. pylori isolates was determined by E-test.

RESULTS: A total of 121 H. pylori strains were isolated, 50 from male and 71 from female patients. Data showed that 44% (n = 53), 20% (n = 24), 5% (n = 6), and 3% (n = 4) of all strains were resistant to the antibiotics metronidazole, amoxicillin, clarithromycin, and tetracycline, respectively. When the antibiotics were considered together we found 11 sensitivity patterns for the strains. Resistance to metronidazole was significantly higher in female than in male patients (P < 0.05). In about 71% of the metronidazole-resistant isolates, the minimum inhibitory concentrations (MICs) exceeded 256 μg/mL.

CONCLUSION: We found a moderate rate of primary resistance to metronidazole. However, a high MIC (> 256 mg/L) which was found in 71% of the isolates is considerable. In the case of amoxicillin, an increased resistance rate of 20% is worrying. Resistance to clarithromycin and tetracycline is also emerging among the H. pylori strains in our region.