Deadly bacteria and ineffective antibiotics

Deadly bacteria and ineffective antibiotics

Recently, a woman in her 70s reportedly died at Nevada, USA, due to bacterial infection caused by a dangerous strain, Klebsiella pneumoniae, which could not be treated even with 26 different antibiotics. The World Health Organisation has referred to Klebsiella pneumoniae as “an urgent threat to human health.”

Clearly, this is an alarming situation where microbes, which are continuously pitted against antibiotics, have gained an upper hand in the struggle for existence. Antibiotics are the only armour that man possesses against bacteria and, therefore, intensive R&D efforts are underway to maintain a scientific edge over these teeny weeny creatures that can wreak havoc on our lives.

The aim of any life form is to multiply for survival on planet earth. For over a century, the mankind has been in a race with bacteria to overpower it with antibiotics.

Today, science seeks to maintain a lead over microbes with a few antibiotics which are effective — but the gap is rapidly narrowing down with the emergence of ‘smart’ bacteria. These are bacteria which have become multidrug resistant like the notorious Staphylococcus aureus (MRSA) which invades the Intensive Care Units (ICUs) in hospitals.

Lately, the multidrug-resistant bacteria, Klebsiella pneumoniae has assumed dangerous proportions especially in ICUs where it causes urinary tract and respiratory tract infections.
This bacteria belongs to the group of Carbapenem-resistant Enterobacteriaceae (CRE) which are multidrug resistant and proves a nightmare for scientific and medical communities alike who have to fight the battle against this strain both in laboratories and hospitals.

In 2008, a Swedish tourist fell ill in New Delhi and did not respond to many classes of antibiotics. Finally, the doctors isolated a Klebsiella strain resistant to almost 10 different kinds of antibiotics.

This bacterial strain was labelled ‘superbug’ since it had a powerful antibiotic resistance gene which could easily be transmitted to other bacteria. These superbugs have a special enzyme called NDM — New Delhi Metallolactamase — which can destroy antibiotics.

In order to combat this dreaded super bug, scientists globally seek to discover more potent antibiotics to save mankind from death by infection.

A 2011 study published in the scientific journal The Lancet revealed the presence of this super bug even in tap water samples in Delhi. This shows that the superbug was not contained in the labs and hospitals alone but has managed to pervade the environment with its dangerous presence. Clearly, since 2011, these bugs would have further contaminated the physical environment.

Antibiotics, as one of the major discoveries in the early 20th century, contained, to a large extent, the premature death of animals and humans over the last century. The absence of antibiotics killed millions between the 13th and 17th century when Bubonic plague, popularly known as ‘black death,’ swept Europe.

Microbes which constitute both fungus and bacteria, can also cause havoc indirectly — like the Great Irish Famine (1845-52), when a fungal pathogen devastated the entire potato crop in Ireland that resulted in the death of over 10 lakh people and displacement of many more.
The first chemically synthesised antibiotic, Salvarsan, popularly called ‘Magic Bullet’ was introduced in 1910 to cure syphilis. It proved to be a boon for many people suffering from this dreaded sexually transmitted disease which lacked an effective cure until then.

In 1928, Alexander Fleming isolated the antibiotic, Penicillin from a fungus. During the World War II, this antibiotic proved to benefit thousands of soldiers from immediate death because of the timely administration of this drug.

Without antibiotics, these soldiers would have either died or lost their limbs to infection as amputation was the only option if their limbs were badly infected.

Thereafter, many antibiotics were discovered which could kill virulent bacteria. However, with the advent of antibiotics, humans thought that they had won the war against bacteria. But, sadly, that was not the case.

In 1946, in less than four years after mass production and use of Penicillin, many bacterial strains became resistant to Penicillin. Scientists continued to discover new drugs day in and day out but the ‘smart’ bacteria continued to gain resistance against these drugs too. Bacteria became resistant to antibiotics largely because of the misuse of these drugs by humans. For instance, in India, antibiotics can be bought over the counter at pharmaceutical shops.

Rampantly misused

The problem arose because people started to consume antibiotics even when not necessary like in viral infections, allergies etc. Antibiotics are rampantly misused as additives to poultry and cattle feed.

All these practices have led to the emergence of ‘superbugs’ — bacteria resistant to several classes of antibiotics. Two antibiotics, namely Colistin and Tigecyclin, were the last weapons in the medical arsenal to combat such multidrug resistant bacteria. However, the recent death of the lady in the US suggests that these bacteria have now successfully dented the ultimate antibiotic armour, too.

The issue is time-sensitive because it will not be long before these bugs can pass on their “resistance genes” to other bacteria which already have a different set of resistance genes. Once this happens, these bacteria will not respond even to the strongest antibiotics available now.

Therefore, the medical and scientific communities globally should take immediate action along with their governments to combat the threat to humanity. The first step is to regulate the use of antibiotics to make sure that the bacterial community does not become invincible.

(The writer is Assistant Professor, Department of Life Sciences, Christ University, Bengaluru)