Abstract

The Carnobacterium genus contains nine ubiquitous species of lactic acid bacteria (LAB) isolate from cold and temperature enviroments (Leisner et al., 2007). The species Carnobaterium inhibens is a motile gram-positive bacterium, which has been isolated for the first time from the intestine of the Atlantic Salmon (Salmo salar) and has the capacity to inhibit the bacterial growth of pathogenic bacteria Vibrio anguillarum and Aeromonas salmonicida by means of the production of bacteriocins and antimicrobial peptides, and being innocuous for fish (Jöborn et al., 1999; Leisner et al., 2007). In our investigation, C. inhibens was isolated and characterized (sequencing of 16S rRNA) by Dr. Victor Garcia, from a sample of fresh water (Rio Mapocho), that crosses the city of Santiago in Chile. Apparently, the organisms belonging to the species C. inhibens are innocuous for its host, in this work we want to demonstrate its effect in C. elegans, evaluated the behavior of the worm and whether it is harmful or not for the life of C. elegans. For this, the first place we conducted growth experiment where the ability to develop and survive of 30 worms (L4) in a lawn of C. inhibens was evaluated, in addition, evasion tests were performed over time (10 min up to 24 hours), and finally the affectation of C. inhibens to worms in larval stage dauer (dauer daf-2 was used at 25 °C). In our results, we observed that after 24 hours of C. elegans feeding with C. inhibens the worm is unable to survive and develop, with 100% death of worms on the plate. This is strongly corroborated in the avoidance experiments, where the worms having the option to escape from the bacteria begin to quickly avoid C. inhibens and in only 10 min of exposure there is a 25% of pathogenic evasion, having at 24 hours 100% avoidance. Finally, we wanted to show if the larva dauer (daf-2 at 25 ° C) is also affected by contact with the bacterium C. inhibens, we found that the worms when kept in dauer can move normally in the grass of bacteria without having an apparent affectation. This could be showing that, C. inhibens is not an innocuous bacteria for the universe of hosts that could have and that failing as it is for the case of C. elegans is so harmful that it quickly causes its inactivity and death.