@article {38554,
	title = {Ultrastructure of coccoid viable but non-culturable Vibrio cholerae},
	journal = {Environmental MicrobiologyEnvironmental Microbiology},
	volume = {9},
	year = {2007},
	type = {10.1111/j.1462-2920.2006.01150.x},
	abstract = {Morphology of viable but non-culturable Vibrio cholerae was monitored for 2~years by scanning and transmission electron microscopy. Morphological changes included very small coccoid forms, after extended incubation at 4{\textdegree}C and room temperature, and sequential transformation from curved rods to irregular (\~{}1~μm) rods to \~{}0.8~μm coccoid cells and, ultimately, to tiny coccoid forms (0.07{\textendash}0.4~μm). Irregular rod-shaped and coccoid cells were equally distributed in microcosms during the first 30{\textendash}60~days of incubation at both temperatures, but only coccoid cells were observed after incubation for 60~days at 4{\textdegree}C. When V.~cholerae O1 and O139, maintained for 30{\textendash}60~days at both temperatures, were heated to 45{\textdegree}C for 60~s, after serial passage through 0.45~μm and 0.1~μm filters, and plating on Luria{\textendash}Bertania (LB) agar, only cells larger than 1~μm yielded colonies on LB agar. Approximately 0.1\% of heat-treated cultures were culturable. Cell division in the smallest coccoid cells was observed, yielding daughter cells of equal size, whereas other coccoid cells revealed bleb-like, cell wall evagination, followed by transfer of nuclear material. Coccoid cells of V.~cholerae O1 and O139 incubated at 4{\textdegree}C for more than 1~year remained substrate responsive and antigenic.},
	isbn = {1462-2920},
	author = {Chaiyanan, Saipin and Chaiyanan, Sitthipan and Grim, Christopher and Maugel, Timothy and Huq, Anwar and Rita R. Colwell}
}
