A rare antibiotic-resistant bacterial infection has been found in a Laramie County resident receiving care at Cheyenne Regional Medical Center (CRMC), according to a statement earlier this year by the Wyoming Department of Health (WDH) . Recent testing showed the organism infecting the patient, an enterobacteriaceae, also included a rare antibiotic-resistant gene known as MCR-1. It does not appear the infection was acquired at the hospital.

The mcr-1 gene makes bacteria resistant to colistin, which is used for multidrug-resistant Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter including NDM-1 metallo-β-lactamase multidrug-resistant Enterobacteriaceae.

Colistin has been categorized as one of the few “Reserve Group Antibiotics” by the WHO in its “Model List of Essential Medicines Amended August 2017”. According to the WHO, Reserve Group antibiotics should be treated as “last resort” options that should be accessible, but whose use should be tailored to highly specific patients and settings, when all alternatives have failed (e.g., serious, life-threatening infections due to multi-drug resistant bacteria).

Besides colistin (polymyxin), other last-resort antibiotics included in the WHO list are: Aztreonam, 4^th generation cephalosporins (cefepime), 5^th generation cephalosporins (ceftaroline), oxazolidinones (linezolid), tigecycline and daptomycin.

Emergence of the first mcr-1 gene, which confers polymyxin resistance, was reported from China in 2015 (The Lancet Infectious Diseases, Published Nov. 18, 2015). As of November 2, the mcr-1 gene has been identified in human isolates in 19 states and in animal isolates in two states in the US, according to the CDC.

These reported cases highlight the dissemination of extensively drug-resistant and pan-drug-resistant Gram-negative bacteria, which have become a significant danger to public health.

This means that colistin resistance is spreading globally.

With no new antibiotics on the horizon, the situation may revert to a ‘pre-antibiotic era’ as the WHO has also warned, unless steps are taken urgently to check this public health danger.

The WHO says that “These medicines (reserve group antibiotics) could be protected and prioritized as key targets of national and international stewardship programs involving monitoring and utilization reporting, to preserve their effectiveness.”

Colistin is misused in the meat and poultry industry in India for its growth-promoting effect.

Reportedly, government agencies including the department of animal husbandry, dairying and fisheries, Food Safety and Standards Authority of India, ministry of agriculture and farmers’ welfare, ministry of health and family welfare and the drug controller general of India have examined the issue and recommended that colistin cannot be used (Live Mint, Dec. 4, 2018). This needs to be implemented with immediate effect. A colistin use policy needs to be formulated to promote its rational use and prevent emergence of antimicrobial resistance to this “last-resort” antibiotic.

It is only through a concerted and coordinated global action that this imminent public health danger can be thwarted.

Prescribing the right antibiotic, at the right dose, for the right duration and at the right time helps optimize patient care and fight antibiotic resistance.

Dr KK Aggarwal

Padma Shri Awardee

President Elect Confederation of Medical Associations in Asia and Oceania   (CMAAO)

Group Editor-in-Chief IJCP Publications

President Heart Care Foundation of India

Past National President IMA