Karma Served by The Ocean By: Galilea Morales

Figure 1. demonstrates the two antibiotic resistant bacterial strains that carry the mcr-1 gene. Both were found in sea water by the authors when conducting their research. The two strains belong to Escherichia coli and are M49 and M78.

We tend to think that antibiotics are super drugs that will rid us of any bacterial inconvenience, but what if that is not the case? The conductors of a study, Drali and colleagues, state how the antibiotic Colistin is seen as a last resort when trying to treat a critical infection that is caused by multidrug-resistant bacteria. What is troubling is that a gene resistant to colistin, mcr-1, was found in a plasmid, a genetic structure that is independent from chromosomes. Humans, animals, and food have been found to carry this gene.

Sewage water ultimately ends up in the sea; this water contains both antibiotic residues and antibiotic resistant bacteria. Because of the elements that are transported to the sea water via the sewage water, things like the plasmids that were previously mentioned, may be transferred on to humans. The authors of the article collected samples from the seawater and 27 antibiotics were tested on isolates that possessed the gene; two strains proved to be resistant (Figure 1).

The reduction of antibiotics used on humans, animals, and in agriculture is of utmost importance because it is the source of seawater contamination and ultimately, antibiotic resistant bacteria.

Original Article:

Drali R, Berrazeg M, Zidouni L, Hamitouche F, Abbas A, Deriet A, & Mouffok F. Emergence of mcr-1 plasmid-mediated colistin-resistant escherichia coli isolates from seawater. The Science of the Total Environment 2018; 642: 90-94.