Conclusion
Most of the microbes in humans live a harmonious existence with human cells, but disease and infection can be caused when this balance is disrupted or when the body or immune system is weakened. Microbes can transfer genetic information between one another and this is one of the means by which antibiotic resistance is spread amongst the microbial population. The process is the origin of MRSA.
Beneficial microbes have an important role to play in the breakdown of human waste in sewage plants.