Mesophilic Aeromonas strains from different serogroups: the influence of growth temperature and osmolarity on lipopolysaccharide and virulence.
Growth of mesophilic Aeromonas sp. strains from serogroups O:13, O:33 and O:44 at different temperatures and osmolarity resulted in changes in the lipopolysaccharide (LPS) and virulence of the strains tested, as we had previously reported for strains from serogroup O:34. The effect of osmolarity could be observed when the cells grew at 37 degrees C but not at 20 degrees C. Purified LPS from cells cultivated at 20 degrees C (high or low osmolarity) or at 37 degrees C at high osmolarity was smooth, whereas the LPS extracted from the cells cultivated on low osmolarity was rough. The smooth strains were resistant to the bactericidal activity of non-immune serum, while the rough strains were sensitive and showed better adhesion to Hep-2 cells than the rough strains. Furthermore, the smooth strains were more virulent for fish and mice than the rough strains. For mesophilic Aeromonas sp. strains from serogroups O:1 to O:44, these changes were not observed, except for serogroups O:13, O:33, O:34 and O:44.
Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, Spain.
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S
Merino
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A
Aguilar
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Rubires
J M
JM
Tomás
D000333:Aeromonas / Q000254:growth & development* / Q000472:pathogenicity*; D000818:Animals; D001422:Bacterial Adhesion; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000378:metabolism* / Q000382:microbiology; D007928:Lethal Dose 50; D008070:Lipopolysaccharides / Q000378:metabolism*; D051379:Mice; D009994:Osmolar Concentration; D013499:Surface Properties; D013696:Temperature
D008070:Lipopolysaccharides