Adventure Travel Guide to the Microbial World

Bacteriophages, or phages, are a type of virus that specifically target bacteria for resources and reproduction1. The diversity of phages in size, functional capability, and genetic information is exponentially increasing as more are discovered and characterized. In general, phage infect a specific species of bacteria. Almost all phages have similar structures, consisting of a capsid “head” that stores genetic information and a “tail” that is used to interact with a host. Like other viruses, phages do not have a nucleus.

            One of the unfortunate side effects of taking antibiotics to clear bacterial infection is its effect on the body’s microbiome. Antibiotics are generally nonselective in their targets; being put on a regimen of antibiotics can kill off an infection, but it will likely also cause harm to the beneficial bacteria of the patient (Dethlefsen et al., 2008).

Pseudomonas aeruginosa is a notorious opportunistic pathogen best known for causing lung infections in patients with cystic fibrosis and compromised immune systems. Interestingly, this pathogen has the capability of communicating with other bacteria via a phenomenon called quorum sensing. P. aeruginosa produces metabolites, often termed autoinducers, that accumulate during growth.

Coronaviruses (CoVs) can cause significant disease in humans, as was evident in the severe acute respiratory syndrome (SARS) outbreak in 2002, the Middle Eastern respiratory syndrome (MERS) outbreak in 2012, and the ongoing outbreak in Central China of a yet to be genetically defined CoV (2). Currently, there are no approved therapeutics available, however, Agostini et al. details the effects of a nucleoside analogue that potently inhibits human and zoonotic CoVs in vitro.

There is a rather wonderful episode of the hit BBC show ‘Doctor Who,’ where David Tennant’s rendition of The Doctor suggests that the Bees aren’t actually dying off, but they are an alien species leaving of their own accord. Alas, Erick et al. suggest, rather more empirically than The Doctor, that the former condition is the reality; the bees are dying off. (1) 

I have always found that host-parasite interactions are extremely fascinating, especially interactions in which parasites manipulate the host’s behavior. When I was reading about symbiotic relationships for my first assignment and when Dr. Hillyer mentioned Toxoplasma gondii in class, my curiosity for the protozoan increased. As Dr. Hillyer mentioned in class, T. gondii is a protozoan that has several different intermediate hosts with one definitive host.