The effectiveness of antibiotics gets reduced in the presence of multiple microbes, necessitating higher doses, reveals a recent research conducted by Thomas O’Brien, a research fellow at Cambridge university’s Department of Biochemistry, published in ISME Journal. The study found that in treating the bacteria Pseudomonas aeruginosa, staphylococcus aureus and the fungus candida albicans with an antibiotic colistin, it couldn’t function well, though colistin is usually very effective in killing Pseudomonas aeruginosa. All three species-specific antibiotics were less effective against their targets when the three pathogens were present together, the research concluded.