Druggable targets found for S. aureus

 

 

In news:

• Novel protein targets that can be used by candidate drug molecules to kill antibiotic-resistant strains of Staphylococcus aureus, including vancomycin-resistant S. aureus, have been identified by researchers at the Indian Institute of Science Education and Research (IISER) Pune.

 

 

Important facts:

• The protein targets identified are crucial for the growth and survival of the bacteria, and hence S. aureus are less likely to cause mutations in them to confer drug-resistance.
•  Any drug candidate that can bind to the targets will be able to inhibit the protein from functioning leading to eventual death of S. aureus, including the drug-resistant ones.
• The researchers used a small molecule (quinone epoxide) and attached an indole residue to it to increase the ability of the molecule to cross the cell barrier of the bacteria and bind to the proteins.
• Many small molecules lack the ability to cross the cell barrier. By making the small molecular permeable, it became possible to know which proteins are crucial for bacterium’s survival.
• The paper published in Journal of Medicinal Chemistry.
• The small molecule bound to multiple proteins, including a few that are crucial for growth and survival of the bacteria.
• These proteins are crucial as they bind to the DNA activate it for normal cellular functioning.
• The small molecule was found to bind to a particular amino acid (cysteine) that is very important for many catalytic functions in the cell. So inhibiting the functioning of this amino acid (cysteine) can have a cascading effect leading to death of the bacteria.
• The small molecule was found to be very specific to S. aureus and was highly potent in cell culture studies.

 

 

Additional Information:

Staphylococcus aureus :

• Staphylococcus aureus is a Gram-positive, round-shaped bacterium that is a member of the Firmicutes, and it is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin.
• These bacteria are spread by having direct contact with an infected person, by using a contaminated object, or by inhaling infected droplets dispersed by sneezing or coughing.
• Skin infections are common, but the bacteria can spread through the bloodstream and infect distant organs.
• Skin infections may cause blisters, abscesses, and redness and swelling in the infected area.
• The diagnosis is based on the appearance of the skin or identification of the bacteria in a sample of the infected material.
• Thoroughly washing the hands can help prevent spread of infection.
• Antibiotics are chosen based on whether they are likely to be effective against the strain causing the infection.
• The bacteria can spread from person to person by direct contact, through contaminated objects (such as gym equipment, telephones, door knobs, television remote controls, or elevator buttons), or, less often, by inhalation of infected droplets dispersed by sneezing or coughing.

 

 

Antibiotic resistance

• Antibiotics are medicines used to prevent and treat bacterial infections. Antibiotic resistance occurs when bacteria change in response to the use of these medicines.
• Bacteria, not humans or animals, become antibiotic-resistant. These bacteria may infect humans and animals, and the infections they cause are harder to treat than those caused by non-resistant bacteria.
• Antibiotic resistance leads to higher medical costs, prolonged hospital stays, and increased mortality.

 

Key facts

• Antibiotic resistance is one of the biggest threats to global health, food security, and development today.
• Antibiotic resistance can affect anyone, of any age, in any country.
• Antibiotic resistance occurs naturally, but misuse of antibiotics in humans and animals is accelerating the process.
• A growing number of infections – such as pneumonia, tuberculosis, gonorrhoea, and salmonellosis – are becoming harder to treat as the antibiotics used to treat them become less effective.
• Antibiotic resistance leads to longer hospital stays, higher medical costs and increased mortality.

 

 

Prevention and control

Antibiotic resistance is accelerated by the misuse and overuse of antibiotics, as well as poor infection prevention and control. Steps can be taken at all levels of society to reduce the impact and limit the spread of resistance.

 

 

Individuals

To prevent and control the spread of antibiotic resistance, individuals can:

• Only use antibiotics when prescribed by a certified health professional.
• Never demand antibiotics if your health worker says you don’t need them.
• Always follow your health worker’s advice when using antibiotics.
• Never share or use leftover antibiotics.
• Prevent infections by regularly washing hands, preparing food hygienically, avoiding close contact with sick people, practising safer sex, and keeping vaccinations up to date.
• Prepare food hygienically, following the WHO Five Keys to Safer Food (keep clean, separate raw and cooked, cook thoroughly, keep food at safe temperatures, use safe water and raw materials) and choose foods that have been produced without the use of antibiotics for growth promotion or disease prevention in healthy animals.

 

 

Policy makers

To prevent and control the spread of antibiotic resistance, policy makers can:

• Ensure a robust national action plan to tackle antibiotic resistance is in place.
• Improve surveillance of antibiotic-resistant infections.
• Strengthen policies, programmes, and implementation of infection prevention and control measures.
• Regulate and promote the appropriate use and disposal of quality medicines.
• Make information available on the impact of antibiotic resistance.

 

 

Health professionals

To prevent and control the spread of antibiotic resistance, health professionals can:

• Prevent infections by ensuring your hands, instruments, and environment are clean.
• Only prescribe and dispense antibiotics when they are needed, according to current guidelines.
• Report antibiotic-resistant infections to surveillance teams.
• Talk to your patients about how to take antibiotics correctly, antibiotic resistance and the dangers of misuse.
• Talk to your patients about preventing infections (for example, vaccination, hand washing, safer sex, and covering nose and mouth when sneezing).

 

 

Healthcare industry

To prevent and control the spread of antibiotic resistance, the health industry can:

• Invest in research and development of new antibiotics, vaccines, diagnostics and other tools.

 

Agriculture sector

To prevent and control the spread of antibiotic resistance, the agriculture sector can:

• Only give antibiotics to animals under veterinary supervision.
• Not use antibiotics for growth promotion or to prevent diseases in healthy animals.
• Vaccinate animals to reduce the need for antibiotics and use alternatives to antibiotics when available.
• Promote and apply good practices at all steps of production and processing of foods from animal and plant sources.
• Improve biosecurity on farms and prevent infections through improved hygiene and animal welfare.

 

WHO response

Tackling antibiotic resistance is a high priority for WHO. A global action plan on antimicrobial resistance, including antibiotic resistance, was endorsed at the World Health Assembly in May 2015. The global action plan aims to ensure prevention and treatment of infectious diseases with safe and effective medicines.

The “Global action plan on antimicrobial resistance” has 5 strategic objectives:

• To improve awareness and understanding of antimicrobial resistance.
• To strengthen surveillance and research.
• To reduce the incidence of infection.
• To optimize the use of antimicrobial medicines.
• To ensure sustainable investment in countering antimicrobial resistance.

 

Source)

https://www.thehindu.com/sci-tech/science/druggable-targets-found-for-s-aureus/article29667627.ece