Acta Biológica Colombiana
Print version ISSN 0120-548X
JIMENEZ, AP; IREGUI, CA and FIGUEROA, J. In Vitro/In Vivo Characterization And Evaluation Of Aeromonas hydrophila Lipopolysacharides (LPS). Acta biol.Colomb. [online]. 2008, vol.13, n.2, pp. 147-162. ISSN 0120-548X.
Aeromonas hydrophila isolated from a septicemic disease outbreak in tilapia (Piaractus brachypomusoreochromis niloticus) was used to prepare crude (29.5 mg/ml) and semipurified (106.5 mg/ml) lipopolysacharide extracts (LPS) based on the phenol-hot water protocol (Westphal and Jann, 1965). Protein contents were 2.3% and 0.1% for the crude and the semipurified extracts, respectively, while the polysacharides ranged from 15 to 26%. SDS-PAGE showed 14 Kd bands for the central oligosacharide and lipid A of the LPS. Mice (n=3) (25 ~ 35 g) that were intraperitoneally injected (25 mg crude LPS) showed after the first hour bristled fur, tachypnea and loss of appetite. Congestion (liver, lung), hemorrhages (kidney, lung), leukocytes margination -mainly PMN neutrophils-(liver, lung) were the most remarkable microscopic features. These effects were more evident than those found in controls injected with E. coli LPS (Sigma®). Crude LPS at 10, 20 and 30 mg/ml induced In vitro proliferation of murine mononuclear cells (2 x 105 in 200 ml DMEM) by use of tritiated thymidine. Both the crude A. hydrophila and the control E. coli LPS extracts showed dosed-dependent increasing counts per minute. The A. hydrophila LPS elicited a proliferation very similar to the one induced by the control.
Keywords : Lipopolysacharide (LPS); A. hydrophila; fish; endotoxemia; mononuclear proliferation.