A group of scientists answered a question – which represents a mystery that healthcare professionals have been searching for a solution to since 2018 – about why cholera patients in Yemen do not respond to antibiotics, especially with indications confirming the emergence of genes capable of drug resistance.
The study – in which scientists from the Wellcome Sanger Institute, the University of Toronto, the Pasteur Institute and the University of Sana’a participated, and was published in the journal “Nature Microbiology” – revealed the source of antibiotic resistance that appeared in the bacteria leading the cholera outbreak that is currently affecting Yemen.
Scientists have discovered that there is a fifth type of cholera that contains genetic elements capable of resistance to drugs, including antibiotics, which is the main factor causing the disease during its outbreak in Yemen.
While the source of the outbreak of the disease in Yemen is still unclear, it is certain that it has been endemic in the country since 2016, which is witnessing the largest outbreak of cholera in modern history. Resistance to antibiotics began to appear among cholera patients in 2018, which scientists consider a problem. The crisis has greatly worsened.
Risk gene
After the study team analyzed 260 DNA samples of cholera bacteria collected in Yemen between 2016 and 2019, it was found that the reason was due to the widespread use of azithromycin and other macrolide antibiotics at that time.
The study indicated that pregnant women and children in Yemen with cholera were treated with erythromycin and azithromycin from 2016 until late 2018, at which point there was a sudden change in the antimicrobial susceptibility profile.
The researchers said that these strains, which are considered immune to drugs, were not transported outside Yemen, and their appearance is linked to the long-term contact of their ancestors with macrolide antibiotics, which led to the emergence of less contagious types of bacteria, but they carry antibiotic-resistant genes.
In their study, the researchers characterized the genotype of cholera samples taken from Yemen, and 84% of them contained the genetic subtype “T13” strain, and this copy carried a distinctive plasmid that was found to be the cause of cholera’s drug resistance.
A plasmid is a small circular piece of DNA, found mainly in bacteria and some other organisms such as some yeasts. The plasmid is characterized by its ability to replicate itself independently of the chromosome that carries the main bacterial DNA. It often contains genes that give cells certain properties, such as resistance to antibiotics or the ability to produce certain proteins.
How is resistance done?
Immunology and stem cell expert, Dr. Adeeb Al-Zoubi, believes that the results of this study are intuitive, and it is scientifically known that the use of various antibiotic drugs may put pressure on bacteria to resist the drugs, so the bacteria change their genes to prevent the effectiveness of the antibiotic on them.
Speaking to Al Jazeera Net, Al-Zoubi says that this process leads to the birth of genetically different strains that are resistant to these antibiotics, by creating genetic mutations that change the genes of these bacteria so that they produce effective proteins to resist the action of the antibiotic.
Incorrect use of antibiotics in patients plays a major role in causing these dangerous mutations that allow bacteria to resist antibiotics, according to his speech.
He added, “In this way, various ineffective antibiotics are used by many patients, which leads to partial killing of bacteria, while other bacteria develop themselves to resist this ineffective antibiotic.”
This, in turn, causes the creation of several strains of these bacteria that are resistant to different antibiotics. In most cases, one person may be infected with more than one strain, and the strains merge with each other within the patient’s body, which leads to the creation of bacteria that are resistant to several types of antibiotics at the same time, according to his statement.
With indications confirming the emergence of genes capable of drug resistance, and considering that cholera spreads rapidly in areas that lack clean water and proper sanitation, and can become fatal if not treated immediately, health, nutrition, water, sanitation and hygiene services must be strengthened, and this It is crucial to address the root causes of this situation.