CRE Superbug

In a tug-of-war of sorts between the antibiotics and their target (pathogenic bacteria), antibiotics seem to be steadily losing ground. Every time the antibiotics are upgraded and different permutations and combinations are created, the bacteria come up with a new mechanism to either render it ineffective or they do not let the antibiotic get near the target to function effectively. In this decisive contest, where the progress has been rather slow due to decreased research in newer and more novel antibiotics, the healthcare setting has a lot to lose.

Carbapenems until recently occupied a niche in the habitat of antibiotics. They possessed the quality to act against cephalosporinases and beta lactamases; enzymes coded into the bacterial genome to render the classical cephalosporins and penicillins impotent. Due to this ability of the carbapenems, they were often the last refuge for infectious diseases’ specialists and other doctors to revive patients from their unrelenting infections. 

Now, this last respite has begun to show signs of defeat. Enterobacteriaceae is a family of the bacterial domain that resides in the human gut, and includes some symbionts, commensals and opportunistic pathogens. Some of these commensals which make up the gut flora help in breaking down the complex carbohydrates into simpler and digestible substrates, which otherwise would not be digestible.

Belonging to the enterobacteriaceae family of bacteria are species Klebsiella pneumoniae and Escherichia coli which are pathogenic. These bacteria have begun to express proteinase; an enzyme that breaks down the bonds in the antibiotics, thus rendering them ineffective. These enzymes called carbapenemases are hydrolytic enzymes which break the structure of most of the commonly used antibiotics. The drawback is that, from this emergence of deadly resistance, these enzymes are mostly seen in healthcare settings in patients who are on ventilators and have catheters (urinary or otherwise) who have had a recent history of treatment with cephalosporin antibiotics. This has threatened the clinical utility of this class of antibiotics and brings us a step closer to the challenge of "extreme drug resistance". Time has come for the healthcare system to revise and formulate a new charter with regulations for antibiotic prescriptions.