Concerns over increasing antibiotic resistance of Helicobacter pylori: Is it time for new guidelines?

H. pylori is the most common cause of chronic gastritis. However, the antibiotic resistance of various strains is the main reason for the failure of eradication therapy. This requires pre-therapeutic antibiotic susceptibility testing.

The Gastroenterology Blog
By Dr. Annabelle Eckert

H. pylori: almost every second person is affected

Helicobacter pylori is the most common cause of chronic gastritis. However, the antibiotic resistance of various Helicobacter pylori strains is the main reason for the failure of eradication therapy. For this reason, an adjustment of the therapy for Helicobacter pylori infestation has been announced, because the gram-negative bacterium is developing a persistently increasing resistance. Last year, several scientific studies were published that highlighted their concerns about the serious situation with antibiotic resistance.¹

More than 44% of the world's population is infected with H. pylori. In developing countries, more than half of the population is infected; in industrialised nations, 1/3 of the population is currently affected. In 80-90% of infected people, the infection is asymptomatic. Nevertheless, in some cases it can be fatal: H. pylori causes chronic gastritis, gastric and duodenal ulcers as well as MALT lymphomas (mucosa-associated lymphoid tissue) and stomach cancer. Globally, stomach cancer is the second most common cause of cancer-related mortality. H. pylori is therefore one of the most potent carcinogens and has been designated as such by the World Health Organisation (WHO).²

Worldwide increase in resistance to the most commonly used antibiotics against H. pylori

The five most commonly used antibiotics in eradication programmes are amoxicillin, metronidazole, clarithromycin, tetracycline, and levofloxacin. The research group was able to make the following observations: Overall, amoxicillin resistance did not develop further in general, but there was an increase in Bulgaria, China, Vietnam, and Iran. The scientific findings on metronidazole resistance differed greatly depending on the study in question. There were increases and decreases in this specific antibiotic resistance.

Clarithromycin resistance showed stability in France, Russia, Spain, China, Colombia and Chile. An increase in clarithromycin resistance was recorded in Australia, Italy, Taiwan, Belgium, Bulgaria and Iran. With regard to tetracycline resistance, only Iran showed an increase. Levofloxacin resistance was also on the rise in four European and six other countries/regions. Triple resistance was observed in Chile. Multiple antibiotic resistances (≥ 3 active substances) were reported in Bulgaria, Belgium, Taiwan and Iran. This contrasted with a stabilisation of antibiotic resistance in H. pylori strains in France and Spain.²

Factors influencing the development of H. pylori antibiotics

The following factors can be important influencing factors for the development of resistance:

Patient compliance during the use of antibiotics.
The national consumption of antibiotics.
The use of non-recommended treatment regimens.
The excessive use of azithromycin during the COVID-19 pandemic.
The virulence of H. pylori strains.
Host factors².

The evaluation of the studies on the development of resistance in the USA and France revealed that the absence of an increase in antibiotic resistance or a decrease in resistance rates correlated positively with:

The decrease in national antibiotic consumption of the antibiotic in question.
Adherence to the latest guidelines for the treatment of H. pylori infections.
A strict antibiotics policy².

Sources

https://www.gastroendonews.com/PRN/Article/02-24/helicobacter-pylori-upcoming-treatment-guidelines/72775.
Boyanova L. et al. (2023). Evolution of Helicobacter pylori Resistance to Antibiotics: A Topic of Increasing Concern. Antibiotics (Basel). 2023 Feb 4;12(2):332.