Biofilms are everywhere – in dental plaque and ear canals, on contact lenses and in water pipelines – and the bacteria that make them get more resilient with age, finds a new study in FEMS Microbiology Letters.
Because bacteria in biofilms resist antibiotics, the study may have long-term implications for medical researchers seeking to develop better drugs and less infection-prone devices.
Biofilms are bacterial cities clinging to a surface. In addition to aiding infections, they can hamper industrial processes by clogging pipelines and gumming up machinery.
And as the study shows, biofilms may hold lessons for scholars of evolution.
Authors Steven Finkel and Alison Kraigsley of USC College found evidence of natural selection in a single-species bacterial biofilm. Finkel is associate professor of molecular biology. Kraigsley is a graduate student in Finkel’s group.
“The bacteria that originally formed the biofilm are not the same as the bacteria that we harvest from that same biofilm later,” Finkel said. “The mutants we find are more fit than the original founding strain.”
The biofilm experiment is a variation on the Finkel group’s best-known work: their studies of how starvation of microbes in a closed environment leads to the emergence of a dominant type of cells known as GASP mutants, for Growth Advantage in Stationary Phase.
GASPers, as Finkel calls them, outcompete bacteria from younger cultures. The key is not the age of individual microbes but the age of the culture they come from: young offspring of GASPers exhibit the same dominance as their parents.
Our five-year-old has chronic sinus infections, one of the specialists he has recently seen said the mucous might be resistant to antibiotics. We’ll hopefully be finding this out within the next couple of weeks.
The FDA says bacteria becoming resistant is a real threat.
“Bacteria and other microorganisms that cause infections are remarkably resilient and can develop ways to survive drugs meant to kill or weaken them.”
Although their page devoted to this topic has not been updated in several year.
I am sure by now you have heard about MRSA or more scientifically know as methicillin-resistant Staphylococcus aureus. The bacteria is resistant to antibiotics and is common worldwide. In recent years many countries have recorded MRSA infections in healthy people who had not been hospitalised or stayed in other healthcare facilities or institutions, nor received medical procedures in the previous year.
According to the Centers for Disease Control and Prevention, an estimated 95,000 people in the United States developed serious MRSA infections in 2005 (the latest data available).
While the CDC cannot say how many children were infected, the agency reported the greatest increase in hospital visits were among those under 18 during an eight-year period ending in 2005.
I believe more and more of these types of strains will be developing at a rapid pace for years to come. And I specifically see this becoming more and more of an issue with young children which makes me incredibly sad.
Anne Buboltz, a postdoctoral fellow in veterinary and biomedical sciences at Penn State, explains that “antibiotic resistance is a natural result of evolutionary pressures.” Just as animals evolve to evade predators or survive in harsh climates, bacteria evolve to withstand the things that threaten them-and these include antibiotics. “Bacteria with an antibiotic resistance gene can survive where non-resistant bacteria do not,” says Buboltz. These survivors then reproduce, and the resistant strain becomes more common.
Have we unwittingly forced this natural process into overdrive? Buboltz believes so, noting, “The widespread use of antibiotic drugs creates a greater force of selection for bacteria with antibiotic-resistant genes.” And that use is on the rise. Some of the increase is due to other miracles of modern medicine: many diseases that used to be deadly can now be treated with transplants or chemotherapy, and as ill patients live longer, they often require long and repeated courses of antibiotics.
We’ll see how it all turns out.