Agriculture Reference
In-Depth Information
Table 10.7
Summary of
in vivo
probiotic applications with zebrafish.
Potential probiont
Parameters
investigated
References
Lb. rhamnosus
IMC 501
F
Gioacchini
et al.
(2010a)
Lb. rhamnosus
IMC 501
F
Gioacchini
et al.
(2010b)
Lb. rhamnosus
IMC 501
F
Gioacchini
et al.
(2010c)
Lb. rhamnosus
IMC 501
GM, F
Gioacchini
et al.
(2011)
Lb. rhamnosus
IMC 501
GM, F
Gioacchini
et al
. (2012)
Lb. rhamnosus
IMC 501
F
Giorgini
et al.
(2010)
Lb. rhamnosus
IMC 501
F
Gioacchini
et al
. (2013)
Lb. rhamnosus
IMC 501
GP, LD
Avella
et al
. (2012)
Lb. rhamnosus
and
Lb. casei
F, GH , GM ,
I R
Q i n
et al
. (2013)
37 commensal or probiotic Gram-positive
and Gram-negative bacteria often used as
probiotic strains in the food industry
and/or aquaculture
DR, IR
Rendueles
et al
. (2012)
Lactobacilli (multiple species)
DR, GM, PA
Zhou
et al
. (2012a)
B. coagulans
DR, IR, PA
Pan
et al
. (2013)
Genera abbreviations:
B
.
=
Bacillus
,
Lb
.
=
Lactobacillus
.
Parameters investigated: DR
=
disease resistance, GM
=
gut microbiota (inclusive of GI probiont recovery), F
=
fecun-
dity/gonadal development/spawning rates etc., GP
=
growth performance, IR
=
immunological/haematological response,
PA
=
pathogen antagonism.
dietary provision of
Lb. plantarum
JCM 1149 was more effective and enhanced the survival
rate by 33% (when provided at 10
6
cell g
-1
), 60% (10
7
cell g
-1
) and 50% (10
8
cell g
-1
). These
findings imply that the capacity of the probiotic to adhere to and populate the GI tract is an
important factor in determining their efficacy in promoting disease resistance. In addition, the
dosage was clearly an important factor also in this study. Similarly,
B. coagulans
fed zebrafish
displayed improved survivability, in a dose-dependent manner, and reduced pathogen translo-
cation/infection levels when challenged with
Vibrio vulnificus
(Pan
et al
. 2013). Although not
always consistently, the following genes were up-regulated in zebrafish fed fodder containing
B. coagulans
at
10
6
CFU (per 50 ml): TLR4 (at 96 h post
V. vulnificus
challenge), TRAM-1
(at 24, 72 and 96 h), NF-κB (at 24, 48, 72 and 96 h), IL-1β (at 24, 48 and 72 h) and TNFα (at
24, 72 and 96 h) compared to control (non-probiotic fed) zebrafish. TLR4 plays an important
function in detecting LPS, present in Gram-negative bacterial cell walls including pathogens
such as
V. vulnificus
, and initiates a downstream signalling pathway which includes the sig-
nal adaptor molecule TRAM-1 and the primary transcription factor NF-κB, which regulates
the transcription of pro-inflammatory cytokines such as IL-1β and TNFα. In turn, NF-κB can
also be up-regulated in a positive feedback loop by pro-inflammatory cytokines such as IL-1β
and TNFα. This is the first study in fish to have assessed the efficacy of probiotics to modu-
late the expression of intermediary genes in the signalling pathway from pathogen detection
(e.g. TLR4) to cytokine gene responses (i.e. elevated IL-1β and TNFα) and demonstrates the
ability of
B. coagulans
to prime the immune response which leads to an elevated ability to
respond to
V. vulnificus
challenge (Pan
et al
. 2013). However, considering that the expression
of downstream signalling molecules and the cytokines were up-regulated (from 24 h) before
TLR4 (96 h) it is likely that other signalling PRRs, such as TLR5, may have been involved
(and potentially earlier) in the detection of the pathogen. Indeed,
V. vulnificus
major flagellin
≥
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