Expression of the collagen adhesin ace by Enterococcus faecalis strain OG1RF is not repressed by Ers but requires the Ers box. Issue 1 (1st May 2013)

• Record Type: Journal Article
• Authors: Cohen, Ana Luisa V.; Roh, Jung Hyeob; Nallapareddy, Sreedhar R.; Höök, Magnus; Murray, Barbara E.
• Is Part Of: FEMS microbiology letters. Volume 344:Issue 1(2013:Jul.)
• Page Start: 18
• Page End: 24
• Publication Date: 2013-05-01
• Subjects: Microbiology -- Periodicals; 579
• DOI: 10.1111/1574-6968.12146
• Languages: English
• ISSNs: 0378-1097

Abstract

<abstract abstract-type="main" id="fml12146-abs-0001"> <title>Abstract</title> <p>Expression of adhesin to collagen of <italic>Enterococcus faecalis</italic> (<italic>ace</italic>), a known virulence factor, is increased by environmental signals such as the presence of serum, high temperature, and bile salts. Currently, the enterococcal regulator of survival (Ers) of <italic>E. faecalis</italic> strain JH2‐2 is the only reported repressor of <italic>ace</italic>. Here, we show that for strain OG1RF, Ers is not involved in the regulation of <italic>ace</italic>. Our data showed similar levels of <italic>ace</italic> expression by OG1RF and its Δers derivative in the presence of bile salts, serum, and high temperature. Using <italic>ace</italic> promoter‐<italic>lacZ</italic> fusions and site‐directed mutagenesis, we confirmed these results and further showed that, while the previously designated Ers box is important for increased expression from the <italic>ace</italic> promoter of OG1RF, the region responsible for the increase is bigger than the Ers box. In summary, these results indicate that, in strain OG1RF, Ers is not a repressor of <italic>ace</italic> expression. Although JH2‐2 and OG1RF differ by six nucleotides in the region upstream of <italic>ace</italic> as well as in production of Fsr and gelatinase, the reason(s) for the difference in <italic>ace</italic> expression between JH2‐2 and OG1RF and for increased <italic>ace</italic> expression in bile, serum and at 46 °C remain(s) to be determined.</p> </abstract>