Isolation of enterotoxigenic Aeromonas from fish

Abstract

This paper reports two different enterotoxigenic classes of the genus Aeromonas isolated from fishes. Strains of A. sobria were isolated from healthy fishes only wheras strains of A. hydrophila were isolated from both healthy and moribund fishes. Aeromonas sobria and hydrophilia strains produced a cytotoxic factor and were highly proteolytic. Seventy-five percent (75%) of the A. sobria strains produced only one type of hemolysis on 5% blood agar, but 92% of the A. hydrophilia produced two types of hemolysis. Enterotoxigenicity of all strains was tested by the rabbit gut loop technique and the suckling mouse test. Most of those Aeromonads were enterotoxigenic. Enterotoxigenic strains appeared to produce two different enterotoxins which were antigenically related, but they seemed to have different mechanisms of action. Enterotoxins of Aeromonas were shown to be antigenically different from those of E. coli.

Molecular Detection of Aeromonas hydrophila as the Main Cause of Outbreak in Tilapia Farms in Egypt

“…The described Postmortem lesions were in agreement with the results described by Asaad [5], Aboyadak [12], Huizinga et al [13] and AOAD [14]. The internal lesions appeared on infected fish were attributed to both bacterial invasion and colonization also, to its produced toxins described by Boulanger et al [15]. Twelve from sixteen isolate were grown on R-S media giving small yellow colonies which are characteristic for Aeromonas hydrophila as described by Cipriano [16] and for confirmation PCR identification was performed.…”

Detection of enterotoxins of Aeromonas hydrophila by a suckling-mouse test

“…Our findings showed that these variables were not reliable for detection of the enterotoxins of Aeromonas. Although Boulanger, Lallier and Cousineau (1977) reported strains of A . hydrophila to be enterotoxin positive in the suckling-mouse test, Cumberbatch et al (1979) and Dobrescu (1978) did not detect the presence of enterotoxins of A .…”

Incidence of toxic Aeromonas isolated from food and human infection

“…Various species of Aeromonas have been associated with cases of gastroenteritis, septicemia and wound, soft tissue, skin and blood infections in humans. In addition, the presence of these bacteria may be fatal in immunocompromised patients [2,4,10,15,17].…”