An insect pathogenic symbiosis between a Caenorhabditis and Serratia

Abstract

We described an association between a strain of the nematode Caenorhabditis briggsae, i.e. KT0001, and the bacteria Serratia sp. SCBI (South African Caenorhabditis briggsae isolate), which was able to kill the insect Galleria. Here we show that the Serratia sp. SCBI lines the gut of the nematode, similar to the Heterorhabditis-Photorhabdus complex, indicating that the association is possibly internal. We also expand on the relevance of this tripartite, i.e. insect-nematode-bacteria, interaction in the broader evolutionary context and Caenorhabditis natural history.

Figure 1

Light microscopic pictures of Caenorhabditis briggsae KT0001. (A) Red Fluorescent Protein (RFP)-tagged Serratia sp. SCBI lining the gut of C. briggsae KT0001. We used plasmid pSPR that harbors the red fluorescent protein gene from DsRedExpress for fluorescent tagging. For a detailed description of the methodology see reference . (B) Differential Interference Contrast image of same worm used in (A). (Scale bar = 100µm).

Figure 2

Light microscopic pictures of Caenorhabditis briggsae KT0001. (A) Red Fluorescent Protein (RFP)-tagged Serratia sp. SCBI lining the gut of C. briggsae KT0001. (B) Bright field image of same worm used in (A) (Scale bar = 100µm).