Marker exchange mutagenesis of the aerolysin determinant in Aeromonas hydrophila demonstrates the role of aerolysin in A. hydrophila-associated systemic infections.
We report here on the isolation of isogenic strains of Aeromonas hydrophila AB3 deleted for a segment of the aerolysin gene. All aer mutants obtained lacked the 49-kilodalton aerolysin gene product and were neither hemolytic for blood erythrocytes nor cytotoxic for Chinese hamster ovary tissue culture cells. One such mutant, AB3-5, was used in a mouse toxicity model to evaluate the role of aerolysin in the pathogenesis of A. hydrophila infections. The strain had a 50% lethal dose (LD50) of greater than 10(9) as compared with the parental strain which had an LD50 of 5 X 10(7). Reintegration of the deleted segment into AB3-5 resulted in an LD50 of 6 X 10(7) cells for this revertant. Furthermore, all mice injected with a sublethal dose of the parental strains developed necrotic lesions; this was never obtained with the aerolysin-deficient strain AB3-5. More importantly, specific neutralizing antibody to aerolysin was detected in mice surviving A. hydrophila infection, demonstrating that aerolysin is produced during the course of systemic A. hydrophila infections.
Chakraborty
T
T
Huhle
B
B
Hof
H
H
Bergbauer
H
H
Goebel
W
W
D000333:Aeromonas / Q000235:genetics / Q000472:pathogenicity*; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D001427:Bacterial Toxins / Q000235:genetics* / Q000276:immunology; D002872:Chromosome Deletion; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006460:Hemolysin Proteins / Q000235:genetics / Q000276:immunology; D007163:Immunosorbent Techniques; D007928:Lethal Dose 50; D051379:Mice; D009154:Mutation; D052899:Pore Forming Cytotoxic Proteins
D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D006460:Hemolysin Proteins; D052899:Pore Forming Cytotoxic Proteins; C032676:aerolysin