Each year, there are hundreds of thousands of deaths from shigellosis worldwide, according to National Institute of Health and Medical Research (Insert). This disease, also called bacillary dysentery, is an infection of the gut caused by bacteria of four species called shigella. In France, it is the Shigella sonnei that mainly circulates. The latter worries the Institut Pasteur, because it is becoming increasingly resistant to antibiotics.
Shigella sonnei bacteria is becoming ultra resistant to antibiotics
The symptoms of shigellosis are diarrhea that lasts 3 to 4 days and resolves spontaneously. But some patients may have more serious symptoms, such as bloody diarrhea. Generally a treatment antibiotic is needed to treat moderate to severe cases or to stop transmission between people in epidemic contexts.
But according to a study published in the journal Nature communication, some strains of Shigella sonnei have become highly resistant to antibiotics. To reach this result, the researchers analyzed more than 7,000 strains of Shigella sonnei and collected epidemiological information between 2005 and 2021.
Ultra-resistant strains (XDR strains for extensive drug resistance) were first identified in 2015 samples of Shigella sonnei.”Subsequently, the scientists found that the proportion of these XDR strains, resistant to almost all antibiotics recommended for the treatment of shigellosis, increased significantly to a peak in 2021: 22.3% of all strains of Shigella sonnei were highly resistant that year (corresponding to 99 cases)”, we can read on the Press release Pasteur Institute.
Only two antibiotics are still effective for shigellosis
After analyzing these XDR strains, scientists noted that they all belonged to “the same evolutionary line became resistant to an important antibiotic (ciprofloxacin) in South Asia around 2007.“Then they spread all over the world, especially in France. For severe cases of the disease, there are only a few effective antibiotics left: carbapenems or colistin. These must be administered intravenously. “Cwhich makes treatment more aggressive with more complex follow-up in a hospital setting”warns the Pasteur Institute.
Of the cases observed in France, some had traveled to South Asia or Southeast Asia and others were men who have sex with men (MSM). “This observation should be taken into account by clinicians and laboratories in the context of consultations for sexually transmitted infections (STIs), with the practice of a systematic antibiogram in the case of isolation of Shigella for better patient care. infected with these highly resistant strains”says the research organization.