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Response of Campylobacter jejuni to combinations of ferrous sulphate and cadmium chloride
Author(s) -
Stern N.J.,
Kazmi S.U.,
Roberson B.S.,
Ono K.,
Juven B.J.
Publication year - 1988
Publication title -
journal of applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0021-8847
DOI - 10.1111/j.1365-2672.1988.tb03382.x
Subject(s) - agar , campylobacter jejuni , chemistry , ferrous , nuclear chemistry , cadmium , cadmium chloride , chloride , agar plate , minimum inhibitory concentration , food science , microbiology and biotechnology , chromatography , bacteria , biochemistry , biology , in vitro , organic chemistry , genetics
On Mueller Hinton (MH) agar, Campylobacter jejuni showed 20.0 and 30.9mm zones of inhibition surrounding discs impregnated with 2.5 and 20 μg CdCl 2 respectively. The minimal inhibitory concentration (MIC) ranged from 0.64 to 3.2 μg CdCl 2 /ml of MH agar for four C. jejuni strains. In the presence of 23 μg FeSO 4 /ml of MH the MIC increased to a range of 1.5–5.4 μg CdCl 2 /ml of MH. Moreover, the numbers of colonies present on MH supplemented with FeSO 4 were greater than on MH without iron. The growth response of C. jejuni in the presence of 0.025% (w/v) FeSO 4 in MH broth was increased about 10000 fold in three of four strains when compared with the growth in unsupplemented MH broth. Zones of inhibition surrounding 20 μg discs of CdCl 2 were 50.6 and 24.4 mm on MH and Campy‐BAP media respectively, with cells grown on MH. These results suggest that the blood‐containing medium ‘neutralized’ the biocidal influence of the CdCl 2 . In comparison, C. jejuni inoculum from fluid thioglycollate (FT) medium showed smaller zones of inhibition. These decreased from 34.9 mm on MH agar to 19.6 mm on Campy‐BAP agar, suggesting that components in the FT growth medium ameliorated the toxic influence of CdCl 2 . Atomic absorption spectroscopy analysis indicated mean values (mg/100 g dry weight) of selected metals bound by C. jejuni as: Cu, 10.4; Mg, 146; Na, 2385; Fe, 45.1; Zn, 13.0; and K, 172.