The Journal of Medical Microbiology, Vol 18, Issue 3 405-411, Copyright © 1984 by Society for General Microbiology
Media for isolation of Aeromonas spp. from faeces
J. Robinson, V. Burke, P. J. Worthy, J. Beaman and L. Wagener
Five solid media were evaluated for isolation of Aeromonas spp. from
faeces: desoxycholate citrate agar (DCA), MacConkey's agar (MAC),
xylose-desoxycholate-citrate agar (XDCA), Rogol's medium (ROG), which
contained ampicillin 20 mg/L and p-nitrophenyl-glycerine 25 mg/L as
inhibitors, and blood agar (BA) with ampicillin 10 mg/L. False negative
oxidase tests limited the usefulness of DCA and MAC and, although the use
of XDCA avoided the problem of fermentation of lactose, some Aeromonas spp.
failed to grow on XDCA or produced minute colonies unsuitable for oxidase
tests. BA yielded the highest rate of isolation for Aeromonas spp. from 323
faecal samples--15.2% for all Aeromonas spp. and 9.3% for enterotoxigenic
(ENT+) strains. This compares with 10.8% for all strains and 6.5% for ENT+
strains isolated on DCA, 7.1% for all strains and 4% for ENT+ strains on
MAC and 4% for all strains and 1.5% for ENT+ strains on ROG. Blood agar
with ampicillin is recommended for isolation of Aeromonas spp. from faeces.
