Essay - Molecular Biology Clostridium Difficile How Important is the Experimental Question...

Molecular Biology Clostridium difficile

How important is the experimental question being addressed to the field?

The study of Matamorous, England, and Dupuy (2007) aimed to present two things. First, the authors would like to provide evidence that TcdC negatively regulates ***** synthesis ***** Clostridium difficile *****xins. Second, the authors also wanted to show that TcdC destabilizes the TcdR-containing holoenzyme. This further suggests ***** TcdC has an ability ***** regulate toxin expression in its unique way. To understand the relevance of the two objectives **********, it must first be established what ***** is. TcdC gene is found at the right end of the pathogenicity locus (PaLoc) of C. difficile. It is ***** along with o*****r *****s such as TcdA, TcdB, and TcdR, genes that positively regulate the production ***** toxins A ***** B. It has been postulated that TcdC negatively ***** the gene expression of these toxin-producing genes (Govind et al. 2006; Matamorous et al 2007). TcdC ***** highly expressed when C. difficile are found to grow exponentially, and expression is silenced when cells enter the stationary p*****e; TcdC expression is upped ***** other toxin-producing genes are shut *****f. There have ***** been studies that demonstrated mutations in the TcdC genes among epidemic strains ***** produce both *****xins ***** and B (Chernak and Johnson 2005; Matamorous et al. 2007).

Evidence to support ***** ***** aforementioned problems ***** relevant to the field of molecular and clinical biology. TcdC is a relatively new discovery. It is a membr*****ne-associated protein with a rel*****tively unknown regula*****ry mechanism. The virulence of C. ***** is due to the synthes***** of ********** produced by *****, TcdB, and TcdR genes. There has also been a growing number of ***** that supports the presence of ***** ***** among ***** strains of C. difficile. To prove that Tcd***** negatively regulates TcdA, ***** and TcdR expression may allow a more in-depth understanding of the pathogenesis of C. difficile. In turn, this may be a good foundation in developing medications ***** could combat the effects of this highly pathogenic microbe. An understanding of the negative regulatory effects ***** TcdC can help in addressing epidemic outbreaks.

Is the design of ***** experiment appropriate and efficient for the *****? How else the ***** might have been designed and ***** an alternate design be b*****ter or worse?

***** quantitative, experimental study essentially had two major parts. First, the authors tested the ability ***** TcdC to repress TcdA expression. This was demonstrated by using in vivo and in vitro models. TcdC *****ive activity was compared to TcdR's augmentative effect in the expression of TcdA. Using C. perfingens to take ***** place ***** C. *****, β-glucuronidase activity was used to measure promoter activity; the lack of β-glucuronidase activity in ***** absence of TcdR demonstrated that there ***** a consequent lack of tcdA expression. This was in contrast ***** the increase in b-glucuronidase ***** with TcdR. However, in the culture with an overexpression of *****, no glucuronidase activity was demonstrated despite the ***** of TcdR. Its ***** to repress