Pisuttharachai, Duangjai
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Pisuttharachai, Duangjai
Alternative Name
Pisuttharachai, D.
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Email
duangjai.pi@kmitl.ac.th
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Item type:Publication, Effects of Diet Supplemented with Morinda citrifolia Fermented Extract on the Growth Performance and Feed Conversion Ratio of Oreochromis niloticus(2022-04-01); ; ;Sangkhonkhet, NatapornThe use of additives in feeds to promote the growth of farmed fish has been rapidly expanding; among these are supplements derived from indigenous plants. Here, we analyzed the effects of satiation feeding of diet supplemented with noni (Morinda citrifolia) fermented extract on the feeding rate, growth performance and feed conversion ratio of Tilapia, Oreochromis niloticus. Fish with an initial average weight of 2.83 ± 0.01 g were fed with diets supplemented with noni fermented extract at 0 (control), 100-, 200-and 300-ml kg<sup>-1</sup> for 12 weeks. Subsequent results showed that growth rate was correlated with or dependent on the concentration of noni fermented extract in the diet. The best result for growth performance, such as weight gain, average daily growth rate and specific growth rate, was found in a fish-fed diet supplemented with noni fermented extract at 200 ml kg<sup>-1</sup>. However, the feed conversion ratio (FCR) is still higher than the control. The high FCR compared to control may be due to the anthraquinone in noni fermented extract, which decreases nutrient absorption. Fish fed with a 300 ml kg<sup>-1</sup> noni fermented extract supplemented diet was the lowest growth performance and highest in FCR, suggesting that concentrations over 200 ml kg<sup>-1</sup> might be detrimental to fish. Taken together, noni fermented extract can be a natural source of feed supplement to improve fish growth performance and may act as an appetite stimulant. However, due to its laxative effect, noni fermented extract supplementation should be given at appropriate levels and effective feeding management. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Molecular serotyping, virulence gene profiling and pathogenicity of Streptococcus agalactiae isolated from tilapia farms in Thailand by multiplex PCR(2017-06-01) ;Kannika, K.; ;Srisapoome, P. ;Wongtavatchai, J.Kondo, H.Aims: This study aimed to biotype Streptococcus agalactiae isolated from tilapia farms in Thailand based on molecular biotyping methods and to determine the correlation between the serotype and virulence of bacteria. In addition to a biotyping (serotyping) technique based on multiplex PCR of cps genes, in this study, we developed multiplex PCR typing of Group B streptococcus (GBS) virulence genes to examine three clusters of virulence genes and their correlation with the pathogenicity of S. agalactiae. The epidemiology of S. agalactiae in Thailand was analysed to provide bacterial genetic information towards a future rational vaccine strategy for tilapia culture systems. Methods and Results: Streptococcus agalactiae were isolated from diseased tilapia from different areas of Thailand. A total of 124 S. agalactiae isolates were identified by phenotypic analysis and confirmed by 16S rRNA PCR. Bacterial genotyping was conducted based on (i) molecular serotyping of the capsular polysaccharide (cps) gene cluster and (ii) virulence gene profiling using multiplex PCR analysis of 14 virulence genes (lmb, scpB, pavA, cspA, spb1, cyl, bca, rib, fbsA, fbsB, cfb, hylB, bac and pbp1A/ponA). Only serotypes Ia and III were found in this study; serotype Ia lacks the lmb, scpB and spb1 genes, whereas serotype III lacks only the bac gene. Virulence tests in juvenile Nile tilapia demonstrated a correlation between the pathogenicity of the bacteria and their virulence gene profile, with serotype III showing higher virulence than serotype Ia. Epidemiological analysis showed an almost equal distribution in all regions of Thailand, except serotype III was found predominantly in the southern areas. Conclusions: Only two serotypes of S. agalactiae were isolated from diseased tilapia in Thailand. Serotype Ia showed fewer virulence genes and lower virulence than serotype III. Both serotypes showed a similar distribution throughout Thailand. Significance and Impact of the Study: We identified two major serotypes of S. agalactiae isolates associated with the outbreak in tilapia culture in Thailand. We developed multiplex PCR assays for 14 virulence genes, which may be used to predict the pathogenicity of the isolates and track future infections. Multiplex PCR typing of the GBS virulence genes was developed and might be further used to predict the pathogenicity of S. agalactiae.
