Good Example Of Article Review On Microbe- Quorum Sensing And Social Interactions During Infection
The paper presents a summary review of the work of Pollitt, Harrison and Diggle (2015).
The social behavior of diverse organisms, such as mammals, birds and social insects (bees and ants) has been a research subject for many years. Recently, scientists have been working on social evolution and behavior of individual cells. The social evolution theory bases on studies of helping behavior, group formation, and reproductive cooperation in different organisms. The authors focused on social evolution of microbes.
Previously, two cell types were designated for microbial populations: 1) the producers of public goods (proteolytic enzymes, toxins, and iron-scavenging siderophores); 2) the defectors or “cheats” that only benefit from the availability of public goods.
The test on social behavior of microbes was carried out in stages: mutants were defined, their fitness investigated, the character of fitness correlation explored. The social behavior of the microbes in the form of siderophore production was found for Pseudomonas aeruginosa. When the growth is restricted by iron requirements, the wild-type cells produce the siderophore and siderohpore-null mutants can exploit. This demonstrates that producing of public goods is a social trait, so the behavior of bacteria is social.
The work focuses on bacterial quorum sensing (QS), a process whereby the microbial cells communicate via special signal molecules. The QS signals regulate production of the extracellular public goods. Small concentrations of signal molecules are always produced. Therefore, they do not induce specific behavior. However, when the population density increases, the molecules signal levels also increase. The experiments with Pseudomonas aeruginosa ad Staphylococcus aureus showed that in mixed populations mutants act as cheats and do not respond to QS signals. Thus, they grow slowly but have an advantage because they exploit the public goods of wild-type cells. This process takes place during infection. The environment can change the trait dynamics, highlighting the need for further testing of social behavior.
Pollitt, Eric, J. G., Harrison, Freya, and Diggle, Stephen P. "Quorum Sensing and Social Interactions during Infection". Microbe 10.1 (2015): 17-22. Print.