Haemagglutination Patterns of Aeromonas Spp. Related to Species and Source of Strains

Abstract

The study included 138 A. sobria and 182^1. hydrophila isolated in Perth from samples of diarrhoeal or non-diarrhoeal faeces or from domestic water. Strains were grouped in relation to agglutination of human, horse, rat and guinea pig erythrocytes and the effect of sugars on haemagglutination. Agglutination of red cells of all four species (primary group 1) was most commonly associated with A. sobria, particularly those strains isolated from faeces of patients with diarrhoea. Most A. hydrophila associated with diarrhoea also belonged to group 1 but A. hydrophila from non-diarrhoeal stools or from water most commonly agglutinated human and guinea pig cells but not horse erythrocytes (primary groups 2 and 3). Fucose-resistant haemagglutination (FRHA) of strains in primary group 1 occurred with about 68% of the strains of A. sobria associated with diarrhoea. Mannose-resistant haemagglutination (MRHA) was limited to 29"/' o of strains of A. sobria associated with diarrhoea. The predominance of primary group 1 among strains of Aeromonas spp. associated with diarrhoea and the proportion of these strains showing FRHA suggest that haemagglutination of cells from human, horse, rat and guinea pig, particularly if fucoseresistant, should be considered in a search for characteristics, which possibly contribute to virulence of Aeromonas spp.Abbreviations used in this paper: FRHA, Fucose-resistant haemagglutination; FSHA, fucose-sensitive haemagglutination; MRHA, mannose-resistant haemagglutination; MSHA, Mannose-sensitive haemagglutination; PBS, Phosphate-buffered saline.

The incidence of virulence factors in mesophilicAeromonasspecies isolated from farm animals and their environment

“…There is evidence that haemagglutination patterns vary under different test conditions [2,4], so that putatively different haemagglutination types may merely reflect different amounts of the same haemagglutinin produced under different in vitro conditions. Geographic variation in haemagglutination inhibition patterns has also been noted (17). In the present study nonagglutinating isolates were more likely to be A. caviae than A. hydrophila or A. sobria and this confirms previous findings [17,37].…”

“…Geographic variation in haemagglutination inhibition patterns has also been noted (17). In the present study nonagglutinating isolates were more likely to be A. caviae than A. hydrophila or A. sobria and this confirms previous findings [17,37]. Significant differences in the distribution of haemagglutinin types between the three species of aeromonads have been shown by some workers, the F-G-M' pattern for example being typical of A. sobria [49].…”

“…If one were to use a very strict criterion (P < 0-0001) to accept significance because of the large number of calculations carried out then this association would be rejected, but only just, nevertheless it can be calculated from Tables 1-3 that 67-6% of the cytotoxin producers were also capable of causing haemagglutination. Although haemagglutination of both cell types was significantly related (P < 0-0001) this study confirmed previous reports concerning differences in the ability to haemagglutinate different cell types [4,36,37].…”

Cytotoxic and haemagglutinating activities of motile Aeromonas species

“…In the present study, only 39 YO of Aeromonas strains in group F + G + M + were cytotoxin producers. In contrast, Burke et al, 15 as well as Singh and S a n~a l ,~~ reported a higher degree of association between enterotoxin production by Aeromonas strains and inhibition of HA in the same group (F + G + M +). The interpretation of other inhibition patterns is not conclusive.…”

“…Results show a strong association (100 YO) between cytotoxin production by Aeromonas strains and HA1 in groups F -G -M + and F -G + M + . Burke et al 15 reported that 75% of Aeromonas strains in these groups were enterotoxigenic, whereas Singh and S a n~a l~~ found that most of their strains in group F -G + M + were non-toxigenic. In the present study, only 39 YO of Aeromonas strains in group F + G + M + were cytotoxin producers.…”