Tuberculosis (TB) is a well-known and deadly bacterial disease, with India accounting for about 25% of the world’s TB cases. TB is treated with antibiotics, but these drugs are losing effectiveness as bacteria quickly evolve resistance. Changes in bacterial DNA make them immune to antibiotics, driving Antimicrobial Resistance (AMR). This challenge is growing due to misuse of antibiotics, such as incomplete treatments or inappropriate prescriptions, which give bacteria more chances to adapt. The spread of resistant TB is also fuelled by poor infection control in healthcare settings and crowded living conditions, making it harder to treat TB and other bacterial infections with standard antibiotic drugs.

In most cases, TB affects the lungs. But if the bacteria escape the lungs via blood, it can also infect other organs of the body. Ocular TB is one such example when the infection sets in the patient’s eyes. Dr. Basu, an expert in ocular TB in Hyderabad, has encountered a variety of such cases throughout his career. However, Aditi’s case stands out uniquely, showing the complex and challenging nature of AMR in TB treatment.

Aditi (name changed), a 21-year-old woman, visited her local ophthalmologist in Mumbai in February after experiencing persistent eye inflammation and swelling. Her ophthalmologist conducted a series of tests, including the Mantoux test (commonly used to detect past TB infection) and a chest CT scan to check for any signs of TB. Based on the initial investigations, she was diagnosed with TB and immediately started on a standard first-line antibiotic therapy combined with steroids.

Despite the aggressive treatment approach, the infection remained uncontrolled by first-line antibiotics. Her ophthalmologist also attempted local steroid injections directly into her eye to control the inflammation, but Aditi’s condition continued to worsen. By May, after months of treatment with no improvement, it became clear that there was more to Aditi’s case than just typical TB.

The medical team decided to conduct further tests to determine the exact strain of TB that caused the infection. They collected her sputum (saliva and mucus) sample for a DNA-based test that scans the bacteria’s DNA to check if it is resistant to first-line antibiotics. Aditi’s results revealed that the TB strain she was infected with was resistant to Rifampicin, a crucial first-line antibiotic included in her treatment regimen.

Resistance against Rifampicin, in most cases, hints that the bacterial strain might be resistant against several other first-line antibiotics too. Aditi was diagnosed with multidrug-resistant tuberculosis (MDR-TB), which explained why the standard treatment regimen did not improve her eye condition. Simply put, the first set of antibiotics generally used against TB were not effective in treating her infection.

Aditi was then shifted to a much stronger MDR-TB treatment regimen, which included a combination of second-line anti-TB drugs. But her condition continued to worsen. Drugs used to treat MDR strains also have side effects, including fatigue, nausea, and headaches, which took a toll on Aditi. Her eye condition was only deteriorating and the second-line antibiotics were not doing their job of containing the inflammation, which was extremely alarming.

In June, Aditi was referred to Dr. Basu at his clinic at LV Prasad Eye Institute, Hyderabad. Aditi’s eye was in critical condition, filled with pus. She was at risk of losing her vision entirely. Dr. Basu performed a procedure to extract a sample of the eye pus and sent it to the state laboratory in an attempt to be able to grow the bacteria in the lab. This enabled him to understand better the bacterial strain that infected Aditi’s eye.

TB bacteria, Mycobacterium tuberculosis, is an extremely slow-growing one and divides every 16–18 hours, unlike others, which double every 2-3 hours. It takes weeks to grow this bacteria in culture. So, this process is rarely performed in India for clinical purposes. Nevertheless, the team at the State TB Training and Demonstration Centre Hyderabad could successfully grow the bacteria from the pus extract. Thus, Dr. Basu and his team were on their way to get precise information on the nature of this puzzling, multi-drug-resistant bacterial strain.

Further, a line-probe assay was performed on the bacteria grown from the eye pus. This is a DNA strip-based test that detects DNA mutations in the bacterial strain that confer its resistance. Test results confirmed that Aditi’s infection was not just MDR-TB but had advanced to a more resistant form of TB. In medical terms, she had extensively drug-resistant tuberculosis (XDR TB). This meant that her bacterial strain was extremely resistant to first- as well as second-line antibiotic drugs.

To combat this highly resistant TB strain, Aditi was placed on a treatment regimen that included Bedaquiline, a drug reserved for severe TB cases. Bedaquiline is only prescribed under strict government supervision and permissions. These measures are required to prevent its misuse and to prevent the development of bedaquiline-resistant bacterial strains. Despite the intensive treatment, Aditi ultimately lost vision in her infected eye, and the eye had to be removed to prevent further complications.

Dr.Basu says “Fortunately, thanks to the timely diagnosis of drug resistance and corresponding changes in the treatment regimen, doctors could at least save her life. If she had continued with the standard MDR-TB treatment alone, without introducing Bedaquiline treatment, the infection could have spread from the eye further to other organs, potentially leading to fatal consequences.”

He further adds that “Aditi’s case is not an isolated one.” Dr. Basu often sees patients from densely populated urban areas such as Mumbai, where drug-resistant TB is particularly prevalent. Factors like unregulated drug use, crowded living conditions, and limited access to proper healthcare have contributed to the rise of antimicrobial resistance in these regions. Immigrant populations, who often live in overcrowded environments with poor healthcare access, are particularly vulnerable.

Early identification of drug resistance and the appropriate change in treatment protocol saved Aditi’s life but at the cost of her eyesight. A prosthetic eye was later inserted to restore her physical appearance. This helped her maintain her self-confidence. However, the financial, physical, and emotional toll of the entire process remains with the young woman for her lifetime.

Aditi’s struggles with MDR-TB and survival are a reminder of the fragile balance in the fight against antibiotic-resistant infections—while she made it through, the next patient might not be so fortunate. The time to act against AMR is now!