Antibiotic

What Are Antibiotics?

Antibiotics are like superheroes fighting off the bad guys—bacteria—in our bodies. They come from microorganisms or are fully synthetic and can either kill bacteria or stop their growth, making them essential in treating bacterial infections. But just as superheroes have weaknesses, so do antibiotics: they’re not effective against viruses or fungi.

The History of Antibiotics

Imagine a world where ancient civilizations knew about the healing powers of mold and plants to fight off infections.

References to these beneficial effects can be found in Egypt, Nubia, China, Serbia, Greece, and Rome. The first documented use of molds for treating infections was by John Parkinson in 1567, but it wasn’t until the late 1800s that synthetic antibiotic chemotherapy began in Germany.

Paul Ehrlich’s work on synthetic antibiotics derived from dyes marked a turning point. In 1928, Alexander Fleming discovered penicillin, which revolutionized medicine and earned him the Nobel Prize in Physiology or Medicine in 1945 alongside Ernst Chain and Howard Florey.

Since then, various essential oils have been found to have anti-microbial properties, leading to a new era of antibacterial treatment. The discovery of penicillin by Ehrlich and Sahachiro Hata in 1910 paved the way for modern antibiotics, with Prontosil being developed in 1932 or 1933.

How Antibiotics Work

Antibiotics can be broadly defined as substances produced by microorganisms that fight other microbes. They are used to treat and prevent bacterial infections, but their effectiveness has led to overuse and misuse, resulting in antimicrobial resistance (AMR).

The World Health Organization classifies AMR as a widespread serious threat, with nearly 5 million deaths associated with it globally each year. Antibiotics can be given orally or intravenously, topically for skin conditions like acne and cellulitis, and are used prophylactically in at-risk populations.

Antibiotic Resistance

Imagine a battlefield where the bacteria have evolved to resist the antibiotics—like a game of cat and mouse.

Resistance often reflects evolutionary processes that select for bacterial strains with enhanced capacity to survive high doses of antibiotics. Several molecular mechanisms of antibacterial resistance exist, including intrinsic and acquired resistance.

The spread of AMR occurs globally and imposes a biological cost on resistant strains, limiting their spread in the absence of antibacterials. Plasmids carrying multiple resistance genes can confer resistance to several antibacterials, leading to cross-resistance and emergence of ‘superbugs’ such as MDR-TB strains.

Antibiotic misuse, including overuse and inappropriate treatment, contributes to the development of resistance. Misuse includes excessive use in travelers, incorrect dosages, failure to complete courses, and treating viral infections with antibiotics.

New Strategies for Antibiotics

The fight against antibiotic-resistant bacteria is ongoing, with new strategies being developed. Traditional chemistry-based approaches are still used, but biology-based approaches like immunoglobulin therapy, phage therapy, and fecal microbiota transplants offer promising alternatives.

Natural products are being screened for antibacterial activity, including medicinal plants and soil bacteria. Some natural products inhibit bacterial efflux pumps or suppress antibiotic resistance. Antibody treatments neutralize bacterial exotoxins, while phage therapy involves infecting bacteria with viruses that target specific strains without harming the host’s intestinal microbiota.

Fecal microbiota transplants involve transferring healthy donor stool to patients with C. difficile infection, with cure rates around 90%. Antisense RNA-based treatments use single-stranded RNA to silence essential bacterial genes, which have been shown effective in treating P. aeruginosa pneumonia and methicillin-resistant S. aureus strains.

The CRISPR-Cas9 system can be modified to target bacterial resistance genes or virulence genes instead of viral genes, offering a new approach to combatting antibiotic resistance.

Conclusion

The journey from ancient remedies to modern antibiotics has been long and complex. While we’ve made significant strides in treating bacterial infections, the challenge of antibiotic resistance remains a critical issue that requires ongoing research and innovation. By exploring new strategies and reducing misuse, we can continue to harness the power of antibiotics for the betterment of global health.