Battle stations

Dr Siddharth Chopra

One morning, Renuka Arora, a 50-year-old regional marketing manager, woke up with red, swollen eyes. The sudden itchiness confounded her, since neither eye had shown any symptom the previous evening. Fearing that it might be a case of conjunctivitis, she wore dark glasses. However, the general physician in her neighbourhood diagnosed it as an eye infection and prescribed Ciplox, an antibiotic. Within 24 hours, the infection had cleared. But was there a need for an antibiotic in the first place, asks Dr Siddharth Chopra, senior scientist and microbiologist, Central Drug Research Institute (CSIR-CDRI), Lucknow.

“The point is that it was prescribed without any diagnostic test. All the doctor did was take one look at the eye and prescribe Ciplox—a broad-spectrum antibiotic (BSA) which kills a variety of pathogens. BSAs are like using a bigger hammer on a tiny nail,” said Chopra. The problem, he said, is that there are no diagnostic tests that are fast enough to tell a doctor what sort of pathogen is responsible for the infection. Under the available tests, it takes a minimum of 36 hours for the results to arrive, and in that time, an infection could even prove to be fatal. Also, over time, this sort of widespread usage of BSAs has led to bacteria that are resistant to most antibiotics.

In order to contain the spread of antimicrobial resistance (AMR), a number of scientists, researchers and innovators across India are developing solutions for early diagnostics, newer drugs and preventatives. Chopra and his team from CDRI, in collaboration with IIT Kanpur, have developed a new molecule to combat antibiotic resistance in Staphylococcus aureus—a common, lethal bacteria mostly acquired because of prolonged hospitalisation. This bacteria has become resistant to most drugs over the years, including last-resort antibiotics. The IITK-CDRI study, which is considered a breakthrough in the field, is based on the fundamental principle of how antibiotics attack bacteria.

There are many ways in which antibiotics or antimicrobials fight bacteria. Some do it by attacking the cell wall, stopping bacteria from producing folic acid or inhibiting the synthesis of RNA. Others, such as the one which Chopra and his team are working on, will prevent DNA replication in bacteria, thus keeping them from multiplying. “We inhibit the activity of the enzyme gyrase to prevent the bacteria from multiplying and leading to cell death,” said Chopra. “The enzyme gyrase has two sub-units, A and B. But most fluroquinolones (antimicrobials that target gyrase to control bacterial population) target the function of sub-unit A of gyrase. However, the bacteria have now evolved in a manner that all these existing fluroquinolones have failed to bind to gyrase A. So, the only other option to contain the bacteria is by antibiotics that target gyrase B. Here, our molecule comes into picture. So far, there has been no commercially available drug that targets gyrase B.”

The expertise in chemistry and informatics for the study came from IIT Kanpur, where a team was led by Dr Sandeep Verma, professor of chemistry and chief author of the study. “The new molecule does not affect human cells and when used in combination with fluroquinolones that inhibit gyrase A, the drug becomes effective against bacteria in in-vitro conditions,” said Verma. “The power of this molecule is that it will be able to synergise well with the existing drugs to re-potentiate their activity. This is a strategy to re-sensitise resistant bacteria to existing commercial antibiotics. The drugs become as effective as they were before the bacteria rendered them useless.” Verma and Chopra believe that the day is not far when consuming this molecule with an existing antibiotic will treat infections of the urinary tract or of the respiratory system.

Elsewhere, at the Jawaharlal Nehru Centre for Advanced Scientific Research in Bengaluru, Dr Jayanta Haldar, associate professor of chemistry, is working towards developing a chemical (fatty acid) ‘D-LANA-14’ that can kill Staphylococcus aureus. Haldar published his findings in the journal Bioconjugate Chemistry. “We tried the chemical in mice and found that not only did it kill the bacterium, it did so without any side effects,” said Haldar. “Despite injecting it multiple times, the infections did not become resistant to it. We are exploring this further.” Haldar is also indulging in the chemical modification of older drugs or parent antibiotics such as penicillin, vancomycin and aminoglycosides to overcome the inherent drug resistance. They are also working on preventing the bacterial contamination of the surface of medical implants and devices by developing biodegradable nano-materials that will be immune to antimicrobial activity.

Dr Ranjana Pathania

At the biochemical engineering and biotechnology campus of IIT Delhi, Ravikrishnan Elangovan spends time developing innovative diagnostic solutions that can help doctors identify pathogens quickly and accurately. He is a part of an interdisciplinary research collaboration between India and the UK. “We are looking at diagnostic opportunities for human health, aquaculture and dairy settings, given that AMR is based on a One Health approach, where humans, animals and the environment are involved,” said Elangovan.

“Diagnostic solutions are either unavailable or are too expensive,” he said. His project takes off at the crossroads between technology and medicine. “Our approach is to combine the social science aspect of why people do what they do and then assess what kind of technical intervention would help minimise antibiotic abuse and maximise good health.”

But biotechnologist Dr Ranjana Pathania, who is leading an Indo-Norway project on AMR, says that it is first essential to tackle the ESKAPE pathogens, which the IDSA (Infectious Disease Society of America) classifies as the highest priority pathogens that are highly resistant. Her team is involved in the discovery of novel adjunct molecules that can aid the revival of old antibiotics, which have otherwise been discarded. She talks about efflux pumps. “These are like transporters that help in the flushing out of toxic substances outside the bacteria’s cell walls,” Pathania said. “They can also pump out our antibiotics and prevent them from reaching their target. So, in my lab, the strategy is to block these efflux pumps so that the antibiotics which have become ineffective in the past can be used again.” Her group recently discovered a molecule IITR080027, which obstructs the energy source of the efflux pumps in the deadly pathogen Acinetobacter baumannii, making it sensitive to the antibiotics that are routinely administered against respiratory infections or urinary tract infections. “We have also recently discovered a plant-derived efflux pump inhibitor, which stops the flushing out of the antibiotics in the troublesome Staphylococcus aureus,” said Pathania. “So, rather than discovering novel antibiotics, which will take anywhere between 10 to 15 years and millions of dollars more for clinical trials, we must work with the arsenal we already have. This way, even some of the last-resort antibiotics like carbapenems, against which bacteria have developed resistance so far, can be made effective.”

She is also working on a project to degrade bio-films formed by the pathogens to protect themselves against antimicrobial agents. Another project involves developing noble antibacterials or molecules that target newer pathways in bacteria, complementing the existing pathways already targeted by the older antibiotics. The point is to discover molecules that target multiple pathways so that it will be difficult for the bacteria to develop resistance.

Most scientists complain that the funding for drug research in India, which would bring millions of dollars to the country, has been hampered by the pursuit of indigenous therapeutic innovations. On the other hand, though, a number of startups are coming up with creative ideas and products that help in the fight against AMR. Spotsense, a group from Bengaluru headed by Amrita Sukrity, is fast developing a test for diagnosing sepsis in newborns. “In India, about eight out of every 20 babies in the NICU are put on antibiotics,” noted Sukrity. “We provide diagnostic solutions that help diagnose a disease early, and are based on evidence rather than clinical symptoms alone. Accordingly, our product to deal with sepsis is now in the clinical validation stage and we are planning a launch in January 2020.”

Dr Taslimarif Saiyed, CEO and director, Centre for Cellular and Molecular Platforms (C-CAMP) in Bengaluru, has been facilitating innovation among startups in the area of AMR for the last five years, under three main verticals: preventatives, diagnostics and new drugs. Bugworks, a five-year-old drug research company, raised $9 million last year after it designed the antibiotic called novel bacterial topoisomerase inhibitor (NBTI), which is highly effective against several multi-drug resistant bacterial pathogens. “We have 10-odd innovations that revolve around AMR,” said Saiyed. “One company, Biomoneta, is working towards reducing the burden of airborne pathogens in the closed settings of an ICU. It is a very encouraging development and, hopefully, we can tackle the menace of AMR efficiently.”