Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/18/2008
Publication Date: 4/18/2008
Citation: Lee, J.-E., Jeong, P.-Y., Joo, H.J., Oh, W.-S., Carta, L.K., Chitwood, D.J., Paik, Y.-K. 2008. Physiological characterization of Diploscapter coronatus strain LKC25 [abstract]. In: Program of the East Asian Worm Meeting, April 18-21, 2008, Shanghai, China. p. 95. Interpretive Summary: Not required.
Technical Abstract: Diploscapter sp., a free-living nematode related similar to Caenorhabditis elegans, has been experimentally shown to vector food-borne enterohemorrhagic pathogens such as Escherichia coli O157:H7 and Salmonella enterica. Lack of standard laboratory procedures for the cultivation of Diploscapter has hindered the study of this organism. In this study, we developed optimal culture conditions for Diploscapter coronatus strain LKC25 and studied the basic physiology of this nematode. We found that NGM-G containing 1.5% (w/w) gellan gum supported optimal growth of Diploscapter sp. Progression from eggs to gravid adults occurred over a period of 106 to 110 h (4.4 to 4.6 d) and was associated with four distinct larval stages. Mean life span was 12.2 d at 30 C, 24.3 d at 25 C, and 37.1 d at 20 C (max at 20 C, 56 d). Brood size was similar at 20 C (107) and 25 C (108), but decreased at 30 C (95), suggesting that growth temperatures above 25 C adversely affect these worms and confirming that optimal growth occurs at around 20 C. Crowding of D. coronatus in liquid culture did not induce entry into the dauer state. Unlike C. elegans, this nematode also did not enter the dauer state in response to temperature or starvation. Establishment of D. coronatus culture conditions enabled a preliminary screen of an antifungal chemical library for nematode growth-inhibiting compounds. Using a newly established high-throughput screening method (Oh et al., unpublished data), we identified multiple anthelmintic agents. Their antinematodal activity relative to known drugs (e.g., fosthiazate) is discussed.