SUPERBUGS!

Superbugs are antimicrobial resistant microbes that are very difficult to kill with existing drugs or any conventional method known to kill pathogens. Horizontal gene transfer, endospores, and capsules are a few of the mechanisms and structures, respectively, that these acquire which helps them survive and propagate in bad conditions and in high amounts. Frederick Griffith, British bacteriologist, developed an experiment that demonstrates how bacteria interact with each other and share their abilities by horizontal gene transfer which explains how harmless strains become harmful pathogenic strains. These microbes can be found everywhere, from your skin to the water you drink; and commonly found in hospitals.

The Griffith experiment used a culture of Streptococcus pneumoniae that had smooth and rough strains. The smooth pathogenic (S) strain were able to produce capsules that resist phagocytosis by our immune system. The rough harmless (R) strain can not produce capsules. Heat-killed S strain and live R strain were later combined; it was observed that the R strain transformed into the pathogenic S strain by producing capsules. Horizontal gene transfer can explain this result; when the S strain was heat-killed, it broke apart and fragments from its DNA were accepted by the harmless R strain. Now, the harmless strain had the genetic code to produce capsules and become pathogenic. Another method of horizontal gene transfer is by sharing genes via conjugation bridge; antimicrobial resistant microbes share genetic information with other related bacteria so that it can become resistant to antibiotics like the donor cell and become superbugs.