Chemotaxis enables microorganisms to move according to chemical gradients. Although this process requires substantial cellular energy, it also affords key physiological benefits, including enhanced access to growth substrates. Another important implication of chemotaxis is that it also plays an important role in infection and disease, as chemotaxis signalling pathways are broadly distributed across a variety of pathogenic bacteria. Furthermore, current research indicates that chemotaxis is essential for the initial stages of infection in different human, animal and plant pathogens. This review focuses on recent findings that have identified specific bacterial chemoreceptors and corresponding chemoeffectors associated with pathogenicity. Pathogenicity-related chemoeffectors are either host and niche-specific signals or intermediates of the host general metabolism. Plant pathogens were found to contain an elevated number of chemotaxis signalling genes and functional studies demonstrate that these genes are critical for their ability to enter the host. The expanding body of knowledge of the mechanisms underlying chemotaxis in pathogens provides a foundation for the development of new therapeutic strategies capable of blocking infection and preventing disease by interfering with chemotactic signalling pathways.

Bacterial life in the rhizosphere

A global analysis of Pseudomonas putida gene expression performed during the interaction with maize roots revealed how a bacterial population adjusts its genetic program to the specific conditions of this lifestyle.

Background: Oocydin A is an anticancer haterumalide with strong antimicrobial activity against agriculturally important plant pathogenic fungi and oomycetes. Results: The oocydin A gene cluster has been identified and characterized in four plant-associated enterobacteria. Conclusion:The ooc gene cluster is organized in three transcriptional units encoding enzymes that belong to a growing class of trans-acyltransferase polyketide synthases. Significance: Oocydin A has potential agricultural, pharmacological, and chemotherapeutic applications.