P N16 Growth and survival of Arcobacter butzleri in by nig11470


									P N16

Growth and survival of Arcobacter butzleri in chicken juice medium

Hanne Ingmer, Jette Kjeldgaard, Kirsten Jørgensen

University of Copenhagen, Frederiksberg C, Denmark

Introduction: The purpose of the study was to examine growth and survival of the emerging
pathogen Arcobacter butzleri in a chicken juice model system. Arcobacter species are Gram-
negative organisms belonging to the family Campylobacteraceae. In contrast to the
thermophilic Campylobacter the Arcobacter species are able to grow both microaerobically
and aerobically and at temperatures as low as 15 °C. Recent evidence suggests that some
Arcobacter, especially A. butzleri, may be human pathogens as the organisms have been
isolated from clinical cases of human enteric diseases. The main reservoir of Arcobacter spp.
is believed to be livestock animals and several studies have pointed to a high prevalence in

Methods: With the aim of studying zoonotic bacteria in an environment resembling the
passage on meat and meat products we have developed a chicken juice medium, CJM in
which growth and survival can be studied under sterile conditions (Birk et al., Lett. Appl.
Microbiol. 38:66, 2004). In the present study we have compared growth and survival of A.
butzleri (CCUG 30485/LMG 10828/ ATCC 49616) in CJM and brain heart infusion broth (BHI)
that in laboratory conditions provides excellent support of A. butzleri growth.

Results: Growth was investigated in liquid chicken juice medium (CJM) and in BHI growth and
we found that while the cultures reached the same optical density the lag phase was
significantly shortened in CJM compared to BHI at low temperature. When growth was
monitored on plates we observed that CJM is a substantially better growth medium than BHI
and normal sized colonies were observed after 7 days (in microaerobic atmosphere) even at
10 °C. Survival was monitored at 5 °C in liquid media and under these conditions the CJM
also proved to support the greatest degree of survival of A. butzleri with less than one (1) log
reduction after 70 days.

Conclusions: Our data show that the CJM supports growth of Arcobacter butzleri to as low as
10°C and that the chicken juice provides an optimal environment for survival of the organism.
As 10 °C is often encountered in slaughterhouses and meat processing facilities our data
strongly suggests that these environments are ideal for both growth and survival of
Arcobacter butzleri.

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