Thank goodness the summer is over…
…and we are all safely home from the beach! Why? The world’s largest infectious disease society, the Interscience Conference on Antimicrobial Agents and Chemotherapy, or ICAAC, held their annual conference in Chicago last week. From the conference came this alarming hint of a threat we hadn’t considered, dealing with infectious agents present from the most innocuous of sources.
Researchers from the University of Miami examined feces collected from seagulls at Miami Beach weekly during April 2010. Fecal samples were then analyzed for the presence of bacteria, specifically of family Enterobacteriaceae. Members of this family are among the largest colonizers of the intestinal tract of animals, and so it is no surprise that seagull fecal matter is a significant source of these bacteria. The researchers however were looking for the presence of antibiotic resistance in these samples, specifically organisms described as Extended-spectrum beta-lactamase (ESBL), which allows these organisms to be resistant to a number of common first and second line of defense antibiotics.
Fifty two fecal samples were collected, resulting in the isolation of 83 enterobacterial isolates including 9 isolates of E. coli. Eight percent of those 83 isolates were ESBL positive, meaning they were resistant to a number of beta-lactam containing antibiotics. A further 17 percent of the isolates expressed an AMP-plasmid, enabling those isolates to be resistant to a subset of antibiotics. The study is another in a series (here, here, here, here, and here) now confirming that antibiotic resistance of infectious agents is common in seabirds.
So what is going on here? Are the seagulls vast carriers of contagion? Probably, and this goes to further the image in my mind that if pigeons are “rats with wings,” then seagulls are “rats in sailor suits.” The prevalence of antibiotic resistance in these birds is likely a consequence of our living in the age of antibiotics. In the presence of antibiotics, microorganisms will acquire resistance to them, and over time the population of microbes tend to be more resistant to them. This is a critical problem when we consider the patient, and our antibiotics are unable to resolve an infection. However, microorganisms outside of the human body can also become resistant, due to the presence of antibiotics in the environment. And there are increasing amounts of these compounds out there, due to their use in agriculture. This is not the only way that antibiotic resistance occurs, and a BIO230 posting earlier this semester indicated that the pathogens were ready for the presence of antibiotics long before we actually developed them.
I’m worried sufficiently that I’m adding a new post category title for this (Death from the skies!) in honor of this inaugural posting. I’m also adding a poll, so that we can talk about our fears and hopefully dispel any misconceptions. Remember to vote early, and vote often.
Posted on September 24, 2011, in Death from the skies, gross, Microbes in the News, Wash your hands! and tagged Antibiotic resistance, Enterobacteriaceae, Feces, Infectious disease. Bookmark the permalink. 1 Comment.