Scientists push for change of tack in antibiotic use

Mercy Kendi, 26, suffers from persistent sore throat infections that cause her sleepless nights whenever they strike. “They mostly come when I am having flu. My throat becomes painful and it becomes hard to swallow food. I also get fevers and feel fatigued.” To alleviate these symptoms and treat the condition, doctors usually prescribe antibiotics which Kendi has taken countless times as her condition is recurrent. It is such less severe but commonly occurring bacterial infections that are now worrying health experts’ world over due to their immense contribution to antibiotic resistance. These ‘small’ ailments including sore throats, sinusitis, tonsillitis, bronchitis and bladder infections account for 90 per cent of all antibiotic prescriptions. A new paper published in the Plos Biology journal by scientists from the Georgia Institute of Technology warns that the frequent use of antibiotics for the small infections promotes the evolution process that transforms bacteria from being drug sensitive to drug resistant. In the case of upper respiratory tract infections (like sore throat or tonsillitis) for instance, doctors often prescribe amoxicillin aimed at killing bacteria known as streptococcus (strep) that is responsible for most of those infections. But since amoxicillin is a broad spectrum antibiotic, it will not only target the strep but also bacteria in other parts of the body such as E-coli in the gut or stomach. This breeds resistance in different types of bacteria in the body leading to adverse health consequences. “You take an antibiotic to go after that thing in your throat and you end up with gut bacteria that are super-resistant which can cause problems with future infections,” said Sam Brown, senior author of the paper and professor in Georgia Tech’s School of Biological Sciences. He added: “Bacteria that survive these many small battles against antibiotics grow in strength and numbers to become formidable armies in big infections like those that strike after surgery.” According to Samuel Kariuki, Director of the Centre for Microbiology Research at the Kenya Medical Research Institute (Kemri), the more bacteria are exposed to antibiotics, they easier it becomes for the bugs to find innovative ways of overpowering the drugs. Because of antibiotic resistance he said that a myriad of infectious diseases such as pneumonia, tuberculosis, cholera and blood poisoning have become difficult to manage, thus claiming lives of thousands of Kenyans. “If we do nothing to address this problem, a time will come when we will have no antibiotics to deal with bacterial infections. “These drugs are also paramount for the success of life saving medical interventions such as surgical operations, organ transplants or chemotherapy for cancer,” says Dr Kariuki. Even though small infections are deemed as major drivers for drugs resistance, the researchers of the Plos Biology paper were concerned that current drug development initiatives mainly focus on replacing antibiotics used to treat big or severe bacterial infections such as sepsis. “The main arena where the vast portion of resistance occurs is in small infections. So we felt there was a disconnect going on here,” say the researchers. The focus on big diseases could be justifiable since when dealing with severe bacterial infections — such as sepsis, bacteremia or surgical site infections — every minute without an effective antibiotic greatly increases the risk of death among affected patients. Nevertheless, the researchers call for concerted efforts in seeking solutions to counter the drug resistance problem exacerbated by small infections. Since the drug development industry landscape is unlikely to change in the near future, they advocate for the development of alternative treatments for small bacterial infections that will drastically minimise the use of antibiotics or eliminate them their use all together. “It might make sense to give antibiotics less often and preserve their effectiveness for when they’re really needed while developing alternate treatments for small infections,” Brown said. “The aim is to take easier tasks — like sore throats — off of antibiotics and reserve antibiotics for these really serious conditions.” According to the scientists, the new treatments for small bacterial infections should focus on “beating bacteria in their own game” — using alternate means - instead of relying on antibiotics to kill them. Since it has become very difficult for drug companies to come up with novel effective antibiotics for the less severe infections, they stated that developing non-antibiotic therapies for such ailments could prove easier thus encouraging pharmaceutical investment and research into them. An example would be the development of anti-virulence drugs which inhibit the growth of bacteria thus rendering them harmless to human beings. For instance, the strep bacteria which are responsible for most upper respiratory infections usually secrete compounds that promote inflammation and make it easier for the bugs to spread in the body. If an anti-virulence drug is developed to fight those secretions, the treatment would be able to knock down the strep bacteria by rendering them weak and thus unable to cause sickness even as they remain alive in the body. Another alternative to antibiotics would be treatments with bacteriophages. These are viruses that attack bacteria thus slowing down their multiplication and spread into the blood. “Sometimes, all it takes is some push-back against virulent bacteria until the body’s immune system can take care of it naturally.” Dr Kariuki noted that avoiding over the counter drug purchases without doctors’ prescription can also help to curb antibiotics overuse. “People have a habit of relying on antibiotics for anything even if the cause of their sickness is not brought about by bacteria. And this is very wrong.” Agencies

Health

Scientists push for change of tack in antibiotic use