Characterization of Aeromonas virulence using an immunocompromised mouse model.
An immunocompromised mouse model was used to characterize Aeromonas strains for their ability to cause opportunistic, extraintestinal infections. A total of 34 isolates of Aeromonas (A. hydrophila [n = 12]), A. veronii biotype sobria [n = 7], A. caviae [n = 4], A. enchelia [n = 4], A. allosaccharophila [n = 2], A. salmonicida (n = 4), and A. bestiarum [n = 1]) were introduced by intraperitoneal injection into immunocompetent or chemically compromised (using cyclophosphamide) mice. The ability of each isolate to persist in the liver and spleen tissue was monitored at 24 hours after exposure. A majority ofA. hydrophila and A veronii v. sobria strains, but none of the isolates of other Aeromonas species, were capable of persistent colonization (<300 cells/mg spleen and liver tissue at 24 hours). The presence or absence of several putative virulence factors (cytotoxicity to HEp-2, lipase activity, elastase activity, and hemolysis) were determined for each isolate using in vitro tests. There were no correlations between the presence or absence of biochemical test results for putative virulence factors and persistence of the isolate in spleen and liver tissue at 24 hours.
Lye
Dennis J
DJ
National Exposure Research Laboratory, Microbial and Chemical Exposure Assessment Research Division, United States Environmental Protection Agency, Cincinnati, OH 45268, USA. lye.dennis@epa.gov
Rodgers
Mark R
MR
Stelma
Gerard
G
Vesper
Stephen J
SJ
Hayes
Samuel L
SL
D000333:Aeromonas / Q000254:growth & development / Q000472:pathogenicity*; D000818:Animals; D015169:Colony Count, Microbial; D003520:Cyclophosphamide; D004195:Disease Models, Animal; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology* / Q000473:pathology; D016867:Immunocompromised Host; D007153:Immunologic Deficiency Syndromes / Q000139:chemically induced; D007166:Immunosuppressive Agents; D008099:Liver / Q000382:microbiology; D051379:Mice; D013154:Spleen / Q000382:microbiology; D016019:Survival Analysis; D014774:Virulence; D037521:Virulence Factors / Q000032:analysis
D007166:Immunosuppressive Agents; D037521:Virulence Factors; D003520:Cyclophosphamide