It's Halloween week, so we are exploring one of the spookier microorganisms that can infect us. Today we explore the swimmer bacteria cell, Proteus, also known as the swarmer cell. This bacteria is one of the leading causes of catheter-associated urinary tract infections (CAUTI), but its ability to swarm makes it a threat to other organs as well.

After considering a biocide's efficacy, toxicity, kill mechanisms, and bacterial resistance, one must also consider its cost. As with all criteria, it is an issue of balance. If it is an exceptionally effective, broad-spectrum biocide, then a higher cost is tolerable. Add in other benefits and a higher cost becomes even more reasonable. When it comes to silver and copper, the issue of cost in terms of raw materials is obvious. But to do our due diligence, we must look beyond just the raw materials and also look at cost vs. efficacy(and resulting return on investment from additional impact) to see the winner in a clearer light.

Resistance - antibiotic or otherwise - is a game of survival of the fittest. Bacteria strains can be killed by an antibiotic that targets a specific cell mechanism, until a particular bacteria mutates into a strain that is able to survive. Such is the case with MRSA, a strain of Staphylococcus aureus that cannot be killed by methicillin-class antibiotics. But how about resistance to silver and copper as biocides? It turns out that every cell's need for copper makes this metal far, far less likely to cause resistance.

Our bodies are incredible feats of balance, or in biological terms, homeostasis. Completely independent of our conscious minds, our cells are taking in nutrients, reproducing, building proteins, assembling enzymes, all to regulate our organs and systems. Most of the work our bodies perform just needs caloric intake. All the building blocks are there, our systems just need energy. But some of those processes require additional elements that we must ingest specifically for that purpose. These non-organic micronutrients are a variety of metals, since metals' ability to oxidize helps catalyze important biological reactions. But our bodies are not built to tolerate all metals. Some metals can even be toxic. Today we'll explore the relative safety of copper and silver in terms of toxicity to humans.

Today's post covers a vital comparison between copper and silver: Their ability to kill harmful bacteria. Biocidal activity - the active destruction of microorganisms at the cellular level - is the fundamental criteria when considering the two metals as possible infection interventions. We will explore under what conditions these metals kill bacteria in both laboratory and real-life settings. 

Since mankind began using metals, both silver and copper have been used to keep mildew, mold, fungi, and other spoilage at bay. Both metals were even known by the ancients to have anti-infection benefits. We know today that both silver and copper have biocidal properties, and as a result, numerous products have appeared on the marketplace touting these properties as effective in the fight against hospital-acquired infections.  Which is the better choice for use in healthcare facilities? To answer this question, we will compare the two metals across 6 criteria over the next series of posts.

This post continues our series on MRSA in support of MRSA Awareness Month.

To recognize MRSA Awareness Month through October, here are 5 critical facts about MRSA that everyone needs to know. 

There is really no way to overstate the importance of Girolamo Fracastoro's bold proposal about the roots of infection. His idea that infections were caused by "seeds," living things unseen to the naked eye, was followed by deductions that included the spread of contagion, incubation periods, the organs affected by particular infectious agents, the vulnerable age for a particular disease, the idea that a survivor of an infection is protected against future infections, the ability of a disease to pass from mother to child through nursing, and many other valuable observations. His genius, while respected and supported, was not definitively proven until over 100 years later, with the advent of the microscope.