New discoveries of methods of infections as a result of Koch and many others' work have shown that some diseases and conditions are not always caused by a single microbe species. According to a study by Oliver A. Todd and Brain M Peters, a newly discovered interaction between the pathogen "Staphylococcus aureus" and "fungal opportunist" "Candida albicans" is being considered a co-infection that is found in the bodies of sick patients who suffer from different conditions . This kind of synergism was found to be lethal in a separate study conducted by Carlson on mice. When mice were infected with the two pathogens independently, sickness resulted but the mice were able to recover. When infected with both pathogens together, the mice had a near-100% mortality rate, showing that some pathogens cannot be as easily isolated or may need extra techniques and steps that better prove causation of the disease.