Chimeric Pathogens: Something for Everyone?


In the 2011 film Take This Waltz a character played by Michelle Williams "playfully" states to her husband (played by Seth Rogen): "I love you so much that I'm gonna inject your face with a curious combination of swine flu and ebola."  This crazy line prompted me to think about the topic of pathogenic chimeras--no surprise for someone looking for infectious diseases everywhere.

Interest in chimerical pathogens is understandably fascinating but something I find kind of puzzling because pathogens on their own are usually sufficiently deadly. 

However there has been genuine interest in chimerical pathogens proving that this is not a phenomenon just restricted to fiction. For example, the former Soviet Union's bioweapons program (the existence of which was recently denied by Putin decades after Yeltsin admitted its existence) attempted to develop combinations of pathogens such as Venezulean Equine Encephalitis Virus and Vaccinia, possibly for vaccine  and/or virulence increasing offensive purposes. There are also sorts of rumors about chimeras involving Ebola and Smallpox.

The line also made me think about the fact that chimerical pathogens aren't solely the result of human ingenuity and genetic engineering, as many chimeras exist in nature.  A few important chimeras occur in nature. Some important examples of natural chimeras include:

  • Influenza viruses that are the result of gene swapping between avian, human, and swine strains
  • Toxigenic strains of Cornyebacterium diphtheriae, the bacteria that causes diphtheria, which are infected by a bacteriophage that elaborates the namesake toxin prompting symptoms
  • E.coli O157:H7, as it elaborates a toxin derived from Shigella bacteria

Also, bacterial strains such as vancomycin-resistant Staphylococcus aureus are also chimeric in that they gain antibiotic resistance by acquiring the requisite genes from vancomycin-resistant enterococci.

Genetic information is transferrable so it should be no surprise that chimeras are a part of nature. Indeed, they sort of exemplify the malleability inherent in evolutionary biology.

Thinking about the topic more broadly, chimeras of all sorts capture people's imaginations. Perhaps its natural to want to create or have enhanced versions of everything? For example, the uppercut of Mike Tyson coupled to the footwork of Mohammed Ali; the guitar skills of Eddie Van Halen and Angus Young in one person; or, one of my childhood favorites, Serpentor