The role of the<i>phoP</i>transcriptional regulator on biofilm formation of avian pathogenic<i>Escherichia coli</i>

Abstract

<i>PhoP</i> plays an important role as a transcriptional regulator in the two-component <i>phoP/phoQ</i> regulatory system, which is widely present in Gram-negative bacteria. In this study, we used DNA microarray-based technology to evaluate the role of <i>phoP</i> in biofilm formation in avian pathogenic <i>Escherichia coli</i> (APEC). Differences in gene transcription between APEC wild-type and <i>phoP</i> mutant strains were determined. Mutation of the <i>phoP</i> transcriptional regulator affects the expression profile of genes involved in processes such as flagellar assembly, ABC transporters, quorum sensing, and bacterial chemotaxis. Deletion of <i>phoP</i> in APEC reduced biofilm formation, as indicated by crystal violet staining and scanning electron microscopy (SEM). In addition, the <i>phoP</i> gene was found to be associated with changes in bacterial drug resistance and cell-membrane-related properties. This study shows that <i>phoP</i> plays an important regulatory role in APEC biofilm formation, and provides new insights into strategies for preventing and controlling APEC infection.