CHANGES IN BACTERIAL MORPHOLOGY AND HOST DAMAGE AFTER INTRA-PERITONEAL INFECTION BY ESCHERICHIA COLI IN MICE

SANCINETO, CARLOS F.; SUAREZ, AGUSTINA AMALFI ; SANJUAN N.; ALMIRON, MARTA

Mar del Plata

Congreso; Reunion Conjunta SAIC SAI SAFIS 2018; 2018

SAIC

Escherichia coli (E.coli) is a main cause of sepsis in humans after intra-abdominal infections. The pathogenesis of this disease is far from clear. In a previous communication we reported the budding of vesicles from Enteroaggregative Escherichia coli under specific conditions, some of them containing bacterial DNA. The purspose of this work was to study if E. coli was different after provoking sepsis than before, along with the description of the pathology induced by this bacterium in mice. C3H/BiDa mice were intra-peritoneally infected with 4 x 106 cfu of wild-type E. coli and observed until dead. Organs were studied by histology and transmission electron microscopy (TEM) and bacteria by Gram staining and TEM. Mouse blood and plasma were aditionally inoculated in vitro with E. coli, and studied with the same methods. Mice died within 24h and showed spread, lacunal bleeding in the liver, intravascular red blood cells lysis and hepatocytes vacuolation. Also, there were shape changes in the cglomeruli of the kidneys as well as P.A.Schiff positive secretion in renal tubules. Changes in the shape, length and aggregation of E. coli were found in bacteria obtained from intraperitoneal fluid and in vitro inoculated blood and plasma, with a higher expression of 25-80nm budding vesicles, as compares with the controls. Our conclusions are that E.coli appears to be different after having induced the infection than before and that the main changes in the host locate in the kidney and the liver. Further biochemical studies are ongoing.