Pioneering Method Streamlines Colistin Testing for Multi-Drug Resistant Infections
Pune: Doctors at the microbiology department of BJ Medical College have made a groundbreaking discovery in the field of antimicrobial testing. They have developed a new method to examine the susceptibility of colistin, a ‘last resort’ antibiotic used for patients battling multi-drug resistant (MDR) infections. This new method, known as colistin broth disk elution (CBDE), not only saves time but is also more accurate, ensuring the potent drug is given only to patients who will benefit from it.
The importance of colistin in treating MDR infections cannot be overstated. However, before administering colistin, which is highly nephrotoxic (damaging to the kidneys), it is crucial for doctors to confirm its effectiveness against the specific MDR infection to prevent adverse outcomes. Until now, broth microdilution (BMD) has been the gold standard for testing colistin susceptibility. However, BMD is a labor-intensive method and not practical for routine use in many laboratories.
Rajesh Karyakarte, the head of the microbiology department at BJ Medical College (BJMC) and the corresponding author for the study, explained the significance of the new method. “The new method, colistin broth disk elution (CBDE), showed high categorical agreement with BMD and low error rates, making it a viable alternative. Given its simplicity, cost-effectiveness, and reproducibility, CBDE can support antimicrobial stewardship efforts in resource-limited settings,” he said.
The study has led to an innovative method of testing the susceptibility of colistin in high-risk patients admitted to the ICU for serious infectious diseases. Despite its high neurotoxicity, colistin often becomes the only option in many cases for intensivists attending to patients. The CBDE method will help understand the susceptibility of the drug without the need for dilution, saving up to an hour per patient—a crucial factor in government hospitals—while also conserving manpower. The test results are more accurate than the BMD method, aiding better decision-making in patient treatment.
Karyakarte further elaborated, “The research paper titled ‘Comparison of Broth Disk Elution and Broth Microdilution Methods for Colistin Susceptibility Testing in Carbapenem-Resistant Enterobacteriaceae and Pseudomonas aeruginosa’ was published in Cureus, a peer-reviewed journal, on September 8. The paper has been sent to the Ministry of Health and Family Welfare for further consideration. The new method needs more validation, and only then can a policy decision be made to replace BMD with the CBDE method to test colistin susceptibility.”
This development is particularly significant in the context of healthcare in resource-limited settings, where rapid and accurate testing methods are essential to combat the growing threat of multi-drug resistant infections. The CBDE method has the potential to revolutionize the way colistin susceptibility is tested, ultimately leading to better patient outcomes and more efficient use of medical resources.
