TITLE:
Effect of Stress-Adaptation on Antibiotic Sensitivity Profiles of Campylobacter jejuni
AUTHORS:
Geetha S. Kumar-Phillips, Irene Hanning, Michael Slavik
KEYWORDS:
Campylobacter jejuni ; Stress; Stress-Adaptation; Antibiotic Resistance; Antibiotics
JOURNAL NAME:
Advances in Microbiology,
Vol.3 No.1,
March
28,
2013
ABSTRACT: Campylobacter jejuni is one
of the leading causes of human gastroenteritis. Campylobacter jejuni requires special conditions and media
in the laboratory for its growth. In nature, however, this organism is able to
survive in very diverse and hostile environments and produce disease in humans
and animals. The different mechanisms by which C. jejuni survives stressful conditions in the
environment still remain unclear. Stress-adaptation may be one of the factors
helping this organism to survive stresses. Some C. jejuni strains have been found to have increased
antibiotic resistance in last several years. To determine the effect of acid
adaptation on the antibiotic sensitivity profile of C. jejuni, 4 different isolates
of C. jejuni (a human
isolate and 3 poultry isolates) were exposed to an acid pH of 5.5 and then
rechallenged with different stresses. The antibiotic sensitivity profiles of C. jejuni after stress-adaptation were
compared with antibiotic sensitivity profiles of non-stressed C. jejuni using the Kirby
Bauer agar disc diffusion assay. The antibiotic sensitivity profiles of the C. jejuni isolates used in this study
were found to change when the acidadapted bacteria were subjected to further
stresses such as an acidic pH of 4.5, aerobic atmosphere and starvation. In the
majority of the cases, antibiotic-resistant C.
jejuni isolates were
found to be more sensitive to antibiotics after stress-adaptation, but in a few
cases C. jejuni showed
increased resistance. These results indicate that increasing various stresses
in a sequential pattern may, in some cases, reduce antibiotic resistance of C. jejuni isolates.