Growth and lysis of the fish pathogen Moritella viscosa.
OBJECTIVE
The sensitivity to lysis is a profound bottleneck to studies of the fish pathogen Moritella viscosa. The aim of this study was to examine the growth and the lysis process of M. viscosa cells under different physical and chemical conditions.


RESULTS
Growth and cell lysis were studied under different conditions. The growth rate was highest at 15 degrees C and lowest at 4 degrees C, but the cells reached a higher density at 4 degrees than at 15 degrees C and the cells were more stable. The presence of minerals reduced lysis.


CONCLUSIONS
Premature lysis of the cells is dependent on environmental factors. Moritella viscosa should be cultivated and kept in media containing a certain set of minerals and at temperatures as low as 4 degrees C. Formalin favours the stability of cells. The instability of the M. viscosa cells at temperatures above 10 degrees C might be one of the factors responsible for their inability to infect fish at higher temperatures. The presence of DHA in the cell membranes is predicted to be responsible for the susceptibility of the cells to lysis.


CONCLUSIONS
The cultivation of M. viscosa cells is a key factor in studying the pathogenicity of the bacteria and in making an effective vaccine to prevent winter ulcers in farmed fish. The study provided recommendations on how to cultivate M. viscosa and how lysis of the cells can be minimized.
Benediktsdóttir
E
E
Institute of Biology, University of Iceland, Askja, Iceland. eben@hi.is
Heidarsdóttir
K J
KJ
D000818:Animals; D001431:Bacteriological Techniques; D001433:Bacteriolysis; D015169:Colony Count, Microbial; D003470:Culture Media; D005393:Fish Diseases / Q000382:microbiology*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology / Q000662:veterinary*; D034221:Moritella / Q000254:growth & development* / Q000302:isolation & purification / Q000472:pathogenicity / Q000502:physiology; D020317:Salmo salar / Q000382:microbiology; D013696:Temperature
D003470:Culture Media