"Superbugs" In Sewage

Image source: Iqbal Osman/Flickr.

"Superbugs" have been found breeding well in Chinese sewage plants.

Tests at two wastewater treatment plants in northern China revealed antibiotic-resistant bacteria were not only escaping purification but also breeding and spreading their dangerous cargo.

Joint research by scientists from Rice, Nankai and Tianjin universities found "superbugs" carrying New Delhi Metallo-beta-lactamase (NDM-1), a multidrug-resistant gene first identified in India in 2010, in wastewater disinfected by chlorination. They found significant levels of NDM-1 in the effluent released to the environment and even higher levels in dewatered sludge applied to soils (1).

How do they become resistant?

Antibiotic resistant bacteria become resistant when there's a mutation or they acquire an antibiotic resistant gene from another bacteria. Even though we think that this is bad, from the bacteria's perspective it gives them greater flexibility in different environments.

Does this prove evolution?

Some have advocated that superbugs are evidence for macro-evolution. However, this is not so. These resistant bacteria are still bacteria before and after they have the gene. They have never changed to a different type of creature. In fact, some bacteria have had the capability to be resistant to our antibacterials even before those antibacterials were marketed. These means that these capabilities were already built in to the bacterial population for greater survival potential.

(1) http://phys.org/news/2013-12-superbugs-sewage.html#jCp