Superbug bacteria on the move (Part I)

Reading a research paper in the week with a running title ‘Colistin resistance in the USA’ and headed ‘Escherichia coli Harboring mcr-1 and blaCTX-M on a Novel IncF Plasmid: First report of mcr-1 in the USA’, I immediately remembered that I am a citizen of one of the poorest countries in the world, where currently the economy mocks the livelihoods of the majority.

How prepared are we to face the superbug?

The research was conducted by McGann et al., of the Multidrug-resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research in Maryland.

Its findings are not of interest just because they are from the United States, but rather because it should be of a major concern to any health system, most of all, a struggling poorly-funded one.

This superbug has ever been detected elsewhere, but it is more disturbing that it is covering distance.

In the World Health Organisation (WHO) state of antimicrobial medicine report of 2014, it was warned that “we may be entering a post-antibiotic era, in which common infections and minor injuries can kill.”

First, let us understand how drug resistance occurs. This can best be done if we look at the basic pathway that drugs undertake in the body.

The chemistry behind drug action is complicated for it to reach their desired targets in the body. It has to travel through the blood system and enter cells, on their own, and locate the cellular sites they should affect.

There are natural proteins in the blood system and other physical barriers across membranes that can bind chemicals in the drugs, effectively reducing the drug potent amount that will reach the desired target.

Sometimes body cells are capable of flushing drug chemicals away even after the drugs successfully get on the target sites.

When a drug is to fight against microbials, it has to overcome a lot of resistance from body chemicals, microbials themselves and natural physical barriers.

This scenario may leave out some bacteria as survivors which then mend their defence mechanisms more strongly than before against any such drug they faced before.

If local research findings by Makoka et al, published in BioMed Central, are anything to go by, we as a nation are informed that between July 2006 and December 2007 there already was widespread resistance to almost all antibiotics that are empirically used in Malawi.

Writing in the Chemistry World in 2013, Philip Broadwith showed that our modern medicines against bacteria are becoming less and less effective. We are not developing new ones nearly fast enough to keep up.

There are cases of drug resistance in Malawi, more that are yet to be published, but the system manages that by careful combination of antibiotics for suspected resistant bugs.

However, for very dangerously resistant superbugs, including Carbapenemresistant Enterobacteriaceae group (CRE), colistin is used in developed countries as “a last resort antibiotic.” CREs are known to kill 50 percent of patients infected.

It is a scare to know that the superbug bacteria found in the US patient’s UTI is resistant to even colistin, the last resort antibiotic.

This is probably why McGann and colleagues are referring to the discovery as a herald for the emergence of truly pan-drug resistant bacteria. n