Aland, R. Claire

Bryden, Wayne L.

Shini, Shaniko

University of Queensland eSpace

242 FEED ADDITIVES TO CONTROL GUT HEALTH
The Problem
The avian small intestine is lined by a single layer 
of columnar epithelium, which acts both as a 
permeability barrier between the gut lumen and 
the internal milieu, and as an important medi-
ator for nutrient digestion and absorption. The 
intestinal epithelium is composed of differ-
ent types of cells each with a distinct function. 
Enterocytes have important roles in nutrient 
transport, metabolism, and epithelial barrier 
integrity maintenance. Ultrastructural exami-
nation of enterocyte tight junctions, microvilli 
and organelles (i.e. mitochondria) can reveal 
alterations in cellular function. Changes of 
mitochondrial morphology occur in response 
to cellular stress. In mice, intestinal infections 
cause disruptions of mitochondrial structure 
and function. Similar mitochondrial changes are 
likely to occur during gut infections in poultry. 
No previous studies have examined this issue. 
How we investigated or researched  
the problem
A subclinical necrotic enteritis (NE) model was 
developed in broiler chicks to identify mecha-
nisms involved in the pathogenesis, and evaluate 
the efficacy of a probiotic [Bacillus amylolique-
faciens H57 (H57)]. Ten-day old chicks were 
exposed to Eimeria vaccine via drinking water, 
and 5 days later to an administration of Clostrid-
ium perfringens cultures in feed. Transmis-
sion electron microscopy (TEM) of the ileum 
was employed to explore ileal ultrastructural 
changes associated with NE and H57.
Results
The exposure of broilers to subclinical NE 
caused lesions in the small intestine, which 
occurred at significantly higher degree in 
NE-challenged birds when compared to 
non-challenged H57 (P<0.001), and NE-chal-
lenged H57 (P<0.05) birds. TEM examination 
showed that most mitochondria were located 
apically within enterocytes. Preliminary results 
suggest that mitochondria are more abundant (P<0.001) in H57 treated birds than in all other 
groups, including controls. Birds in NE-chal-
lenged H57 treatment also appear to have 
higher (P<0.05) mitochondrial density (75/100 
µm2) than NE-challenged birds (54/100 µm2). 
In control, H57, and NE H57 birds, most mito-
chondria were round or elongated, with mild or 
no structural damage. In NE-challenged birds, 
mitochondria more often were irregular in form, 
containing electron-lucent regions of matrix, 
and with indistinct, swollen or damaged cristae. 
Implications / Conclusions
The role of mitochondria in avian gut health 
needs to be established. Mitochondria can 
undergo dynamic alterations to meet chang-
ing cellular needs or in response to cellular 
stress. These changes may result in lowered 
ATP production and an increase in ROS expo-
sure. Evaluation of mitochondria within the 
enterocyte in birds with gut health problems 
will allow for a more accurate assessment of 
cellular metabolic efficiency and functionality. 
The preliminary results of this study suggest 
that the ultrastructure, distribution and 
density of mitochondria within enterocytes 
may be related to treatment group. It appears 
that dietary addition of H57 increased mito-
chondrial density and probably efficiency, as 
these birds had reduced clinical signs of NE. 
ABSTRACT ID-108
The abundance and morphology of mitochondria in enterocytes of 
chickens exposed to necrotic enteritis and treated with a probiotic
Shaniko Shini1, R. Claire Aland1 and Wayne L. Bryden1 
1 School of Biomedical Sciences, University of Queensland, St Lucia QLD 4071, Australia


The abundance and morphology of mitochondria in enterocytes of chickens exposed to necrotic enteritis and treated with a probiotic

https://espace.library.uq.edu.au/view/UQ:d3237a9/IHSIG2019_Page242.pdf

The abundance and morphology of mitochondria in enterocytes of chickens exposed to necrotic enteritis and treated with a probiotic

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