In nature, the free living nematode C. elegans is found in soil, rotting plants and compost pits, feeding on bacteria and fungi. In the particularly complex microbe-rich environment, these microbes play different roles for C. elegans, including food, parasites, pathogens, and possibly competitors. Recent studies have characterized the natural microbiome of C. elegans and found that despite being originated from different places, the habiting bacteria species in the C. elegans are similar. Besides, the natural microbiome has a beneficial effect on worms growth and resistance to stress. Since worms living in the native habitats carry a species-rich microbial community, there are also full of challenges with various pathogens. At present, more than 40 microbes are pathogenic to C. elegans, such as bacteria, fungi, and viruses and the major routes of infection are through the intestine and the epidermis. Moreover, the responses of the nematode to different bacteria are established on the basis of host defenses and bacterial virulence mechanisms.
In particular, as a key model organism within biology, its transparent gut, rapid growth rate and its bacterial diet make C. elegans a powerful system to study host-bacteria interactions. For the research of bacteria-worm interaction, the quantification of the intestinal bacterial load is an indispensable part as well as detecting the ability of bacteria to colonize the animal's gut. Here we offer services to accurately quantify bacterial colonization proficiency in C. elegans, hoping to bring convenience to customers in the related research.
Here we apply the method of homogenization and serial dilution to isolate bacteria from C. elegans. Since contamination with airborne microorganisms in the laboratory environment can lead to a serious problem for microbiome analyses, the procedure of the experiment requires strict laboratory conditions. We have a specific separate lab installed with a laminar flow cabinet. The lab is repeatedly disinfected, therefore ensuring a high sterility condition for conducting the experiments. In addition to minimizing the general microbial contaminations, we also take measures against the presence of microorganisms from the surface of the nematodes in order to avoid interference in the analysis of microbes from within the worm body. For example, all nematode samples are required to wash three times in sterile M9-T before conducting the following procedures.
Synchronized C. elegans larvae are cultured with experimental microbiome for a certain time before applying the washing step to remove bacteria outside of the nematode gut. It is notable that C. elegans embryos extracted from hermaphrodites can be a new generation within exposing anew to a microbe using hypochlorite treatment. This is a unique advantage of the nematode to study host-microbe interactions.
We quantify bacterial colonization by calculating colony forming units (CFU, a measure of individual colony number) in C. elegans intestines. Besides, as a simple method to measure colonization by bacteria tagged with fluorescent markers, the green fluorescent protein (GFP)-expressing bacteria are utilized to assess the degree of intestinal colonization under fluorescence microscopy.
Graphical representation of the C. elegans induction assay using GFP report.
Creative Biogene is a professional C. elegans model service provider. We are dedicated to exploiting the attractive model system C. elegance to promote the progress of related research. If you are interested in our services or have any questions about it, please don't hesitate to contact us.
* For research use only.