Presentation by Golam Sarower on 'Probiotics in aquaculture competitive exclusion of pathogens and immunostimulants against it' at the One Health Approach workshop on Tuesday, 23 March 2021.

1. Probiotics in aquaculture: Competitive exclusion of pathogens and immunostimulants
against it
Prof. Md. Golam Sarower, PhD
Fisheries and Marine Resource Technology Discipline
Khulna University
Khulna 9208, Bangladesh

2. Context
Species Amplicon size
(bp)
Target DNA GeneBank
Accession no.
Corresponding locations
in genome
Vibrio sp. 662 16S ribosomal RNA AF426814 1306483 – 1307092
E. faecalis 318 16S ribosomal RNA AB690253 145 – 463 (partial &
draft)
C. butyricum 383 16S-23S intergenic spacer region CP030775 157363 – 157746
Lactobacillus sp. 250 16S-23S intergenic spacer region AP018405 504119 – 504369
v Viral and bacterial epizootics are major constraints for the successful development of shrimp aquaculture.
v Use of excessive antibiotics and their consequences in shrimp farming has received attention from public health point of view.
v As an alternative strategy to antibiotic in aquatic disease management, probiotics have attracted attention in aquaculture.
v Probiotics are able to confer their effects through the competitive exclusion of pathogens, nutrient and enzymatic contribution to
digestion and enhancement of immune response.
Why indigenous probiotic?
v Terrestrial/exogenous bacteria as probiotics for aquaculture has had limited success.
v Therefore, isolating potential bacteria from the aquatic organisms/environment in which they grow optimally is a better approach.
Methodology
v Isolation of pathogenic and probiotic bacteria from intestine of Macrobrachium rosenbergii.
v Identification of the bacterial isolates by biochemical and PCR
test (Table 1).
v In vitro and in vivo challenge test by isolated probiotics.
v Determination of growth, digestibility, and immune response
of prawn after 2 month culture with probitics
Table 1: Particulars of primers for PCR

3. Findings of our research works
1. Khushi S.S…. & Sarower M.G. (2021) Potential probiotic and health fostering effect of host
gut-derived Enterococcus faecalis on freshwater prawn, Macrobrachium rosenbergii. Aquaculture
and Fisheries (In Press)
2. Sumon M.S… & Sarower M.G. (2018) Growth performance, digestive enzyme activity and
immune response of Macrobrachium rosenbergii fed with probiotic Clostridium butyricum
incorporated diets, Journal of King Saud University – Science, 30: 21-28
3. Ahmmed F…. & Sarower M.G. (2020) Host gut-derived probiotic Lactobacillus sp. Improves
resistance of giant freshwater prawn Macrobrachium rosenbergii against Vibrio harveyi.
Aquaculture International, 28:1709-1724
M 1 2 3 4
Fig 1: PCR products amplified from target DNA of Vibrio sp. (1), E. faecalis (2) , C. butyricum
(3) & Lactobacillus sp (4). Fig 2.: Effect of probiotic on weight gain (%) of M. rosenbergii. Fig
3: Effect of probiotic incorporated feed on amylase and protease activity of M.
rosenbergii1,2,3.
Our research works have been published in the following journals and we
acknowledge BFRI for research grant.
v Vibrio sp., Enterococcus faecalis , Clostridium butyricum and
Lactobacillus sp. were isolated from the gut of prawn and identified
using biochemical and PCR tests (Fig1).
v Pathogenic bacteria (Vibrio sp.) were found to be reduced after 8 h
and 60 days of probiotic administration in the in vitro and in vivo test,
respectively (data not shown).
v Probiotics mixed feed showed higher weight gain and digestive
enzymes activities compared to control group of prawn (Fig 2 & 3).
v The probiotic also improved the immune response by augmenting
non-granular hemocyte (NGH), small granular hemocyte (SGH), and
large granular hemocyte (LGH) in the treatment group (data not
shown).
v Overall, the probiotic bacteria enhanced weight gain, digestibility,
and immune response in the experimental prawn. So, these works
highly relate to sustainable aquaculture and one-health approach.
v We would like to go ahead with identifying candidate genes for
immunostimulant in M. rosenbergii following administration of these
three isolated probiotics.
Figure 1 Figure 2 Figure 3

4. Thank you
@
@sarowerku
https://discipline.ku.ac.bd/fmrt/faculty/sarower
sarower@yahoo.com