Proteomic analysis of ESBL-producing Escherichia coli under bentonite condition

The dissemination of extended spectrum beta-lactamases (ESBL) genes through gene transfer attracts wide attention. Bentonite is widely used as a feed additive in an animal-breeding environment. In order to obtain a better understanding of the effect of bentonite on Escherichia coli carrying ESBL gene, proteomic analysis was carried out to screen the key proteins. The results showed that a total of 31 proteins were differentially expressed, including 21 up-regulated proteins and 10 down-regulated proteins. These proteins were involved in biosynthetic process, metabolic process, stress response, transport, anaerobic respiration, proteolysis, hydrolase, protein folding, transcription, salvage, and other. The transcriptional level of four genes (mipA, gntY, tldD, and arcA) was in consensus with proteomic results. This study revealed the differentially expressed proteins involved when E. coli was incubated under bentonite and PBS condition, which implied the possibility that bentonite may promote the transfer of ESBL gene between E. coli.