scholarly journals Selection of Lactic Acid Bacteria (LAB) Antagonizing Vibrio parahaemolyticus: The Pathogen of Acute Hepatopancreatic Necrosis Disease (AHPND) in Whiteleg Shrimp (Penaeus vannamei)

Biology ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 91
Author(s):  
Linh Nguyen Thi Truc ◽  
Ai Trinh Ngoc ◽  
To Tran Thi Hong ◽  
Tuu Nguyen Thanh ◽  
Huong Huynh Kim ◽  
...  

Acute hepatopancreatic necrosis disease (AHPND) has recently emerged as a serious disease of cultured shrimp. A total of 19 lactic acid bacteria (LAB) strains isolated from shrimp samples were characterized based on morphological characteristics, biochemical tests, sequencing analysis, and their ability to antagonize Vibrio parahaemolyticus, which causes AHPND in whiteleg shrimp. Results from the agar well diffusion method indicated that 3 out of 19 isolated LAB strains showed the highest antagonizing ability against AHPND V. parahaemolyticus strain with an inhibition zone diameter ranging from 18 to 20 mm. Experiments where shrimps were given feed supplemented with these LAB strains and challenged with AHPND strain showed high survival rates (approximately 80.0%), which were not significantly different as compared to those recorded in the negative control treatment (86.6%), but significantly different to those recorded in the positive control treatment (40.6%) after 16 days of the experiment. However, the histological images of shrimp hepatopancreas indicated that the infection rate significantly reduced from 60.0% to 11.1% in shrimps fed with LAB-supplemented feeds and challenged with AHPND V. parahaemolyticus strain as compared to those in the positive control treatment. A polymerase chain reaction (PCR) and 16S rRNA gene sequencing confirmed the identification of LAB strain. These results can be applied in further experiments to investigate the ability of L. plantarum in preventing AHPND in intensively cultured whiteleg shrimp.

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 280
Author(s):  
Linh Nguyen Thi Truc ◽  
Tuu Nguyen Thanh ◽  
To Tran Thi Hong ◽  
Day Pham Van ◽  
Minh Vo Thi Tuyet ◽  
...  

This study aimed to evaluate the growth, survival rate, and resistance to acute hepatopancreatic necrosis disease (AHPND) of white leg shrimp (Penaeus vannamei) by using Lactobacillus plantarum, Lactobacillus fermentum, and Pediococcus pentosaceus mixed with feed, and at the same time supplying CNP in a ratio of 15:1:0.1 to the water. As a result, the treatments that shrimp were fed with feed containing lactic acid bacteria (LAB), especially L. plantarum, have increased shrimp growth, total hemocyte cells, granulocyte cells, and hyaline cells significantly (p < 0.05) in comparison to the control group. The supply of CNP to the water has promoted the intensity of V. parahaemolyticus effects on shrimp health and significantly decreased total hemocyte cells, granulocyte cells, and hyaline cells by 30–50% in the period after three days of the challenge, except in L. plantarum treatment, which had only a 20% decrease compared to other treatments. In CNP supplying treatments, the AHPND infected rate and mortality of shrimp were higher than those in other treatments. In summary, the supply of CNP had significantly reduced the shrimp’s immune response and promoted the susceptibility of shrimp to AHPND in both cases of use with and without LAB-containing diets.


2017 ◽  
Vol 66 (4) ◽  
pp. 473-481 ◽  
Author(s):  
Karina Garzón ◽  
Clara Ortega ◽  
Gabriela N. Tenea

Tropical, wild-type fruits are considered biodiverse “hotspots” of microorganisms with possible functional characteristics to be investigated. In this study, several native lactic acid bacteria (LAB) of Ecuadorian Amazon showing highly inhibitory potential were identified and characterized. Based on carbohydrate fermentation profile and 16S rRNA gene sequencing, seven strains were assigned as Lactobacillus plantarum and one strain as Weissella confusa. Using agar-well diffusion method the active synthetized components released in the neutralized and hydroxide peroxide eliminated cell-free supernatant were inhibited by proteolytic enzymes, while the activity was maintained stable after the treatment with catalase, lysozyme, α-amylase and lipase suggesting their proteinaceous nature. The inhibitory activity was stimulated by acidic conditions, upon exposure to high heat and maintained stable at different ranges of sodium chloride (4–10%). The DNA sequencing analysis confirmed the presence of plw structural gene encoding for plantacirin W in the selected L. plantarum strains. Moreover, we showed that the active peptides of Cys5-4 strains contrast effectively, in a bactericidal manner, the growth of food borne E. coli UTNEc1 and Salmonella UTNSm2, with about tree fold reduction of viable counts at the early stage of the target cell growth. The results indicated that the bacteriocin produced by selected native lactic acid bacteria strains has elevated capacity to suppress several pathogenic microorganisms implying their potential as antimicrobial agents or food preservatives.


Author(s):  
Baso MANGUNTUNGI ◽  
Apon Zaenal MUSTOPA ◽  
Lita MEILINA ◽  
Maritsa NURFATWA ◽  
Leggina Rezzy VANGGY ◽  
...  

Honey acts as an antibacterial without side effects, and also contains antiseptic substances which function to inhibit bacterial growth. This study aimed to isolate the Lactic Acid Bacteria (LAB) in Sumbawa white honey and the bioactive compounds produced as pathogenic antibacteria. The 1st stage in this study was the isolation of lactic acid bacteria (LAB) in Sumbawa white honey, then continued with a grading test, morphological test, catalase test, methyl red test, and the last test, namely the antimicrobial test against 5 pathogenic bacteria (Salmonellatyhposa, Staphylococcus aureus, Escherichia coli, Enterobacter ludwigii, and Leclerciaadecarboxylata). Data analysis was performed using the Analysis of variance (ANOVA) test at a confidence level of 0.05 with SPSS 24. Based on the results of sequencing analysis, it was found that the 5 selected isolates were Enterococcus faecium species. The Enterococcus faecium species obtained from the sequencing results had different strains. The accession numbers of the 5 Enterococcus faecium were: Isolate-03 with a percentage of 97.29 % (accession number: KU324920.1), Isolate-07 has a percent identity of 97.36 % (accession number: MF108201.1), Isolate-09 of 97.73 % (accession number: CP041261.3), Isolate-20 with a percentage of 96.40 % (accession number: MN511819.1), and Isolate-24 with a percentage of 98.61 % (accession number: KM495938.1). These isolates can inhibit the growth of all tested pathogenic bacteria treated with 100 % LAB metabolites and were not significantly different (p > 0.05) compared to a positive control (Ampicillin). HIGHLIGHTS Antibacterial compound of Lactic Acid Bacteria (LAB) from Sumbawa white honey Lactic acid bacteria isolation, characterization, and biosprosprection against pathogens Identified LAB by 16s rRNA sequencing gives five strains of Enterococcus faecium All identified LAB metabolites can inhibit all pathogens by similar inhibition percentage with Ampicillin GRAPHICAL ABSTRACT


Author(s):  
Nguyen Quang Linh ◽  
Khanh Van Nguyen ◽  
Dung Quoc Tran ◽  
Van Khanh Tran Quang

Background: Acute hepatopancreatic necrosis disease (AHPND), is a bacterial disease of whiteleg shrimp, which has a high mortality rate (100%) and incurs economic losses. Our objective was to identify the genes which lead to cell and organ damage and investigate bioproducts to prevent and treat. Methods: Litopenaeus vannamei shrimp in Thua Thien Hue province, Vietnam were collected from an infected pond and analysed at the Institute of Biotechnology, Hue University. The PirA gene of Vibrio parahaemolyticus strain K5 was isolated and analyzed for nucleotide sequence and paired with the expression vector pQE30. The expression vector was transformed into E. coli strain M15, the PirA recombinant protein was expressed in the form of 6xHis-PirA fusion protein of about 15 kDa. PirA recombinant protein was purified and determined the PirAvp binding ratio, cloning and sequencing of PirA gene from Vibrio parahaemolyticus strain K5 causing AHPND by PCR method with specific primers and molecular weights of PirAvp and the PirAvp complex. Results: PirA gene from Vibrio parahaemolyticus strain K5 was cloned into pGEM-T easy vector (Promega, USA) and screened E. coli TOP10 colonies containing pGEM T easy/PirA recombinant plasmid on LB agar/ampicillin/IPTG/X-Gal medium. PCR showing a band of about 347 bp, matching the size of PirA gene and two nucleotide sequences (BamHI and HindIII). The results showed that PirA gene has a length of 336 bp and similar to PirA gene on GenBank (Code: KU556825.1). The results of protein extracted from E. coli M15 recombinant cells and 6xHis-PirA target protein was collected in elution fractions from EF2 to EF6, showed that the concentration of 6xHis-PirA protein and EF3 elution fraction collected a highest protein concentration (1,586.54 &micro;g/ml). Conclusions: The purified PirA recombinant protein will provide materials for development research to create biological products to prevent and treat AHPND.


2020 ◽  
Vol 65 (No. 1) ◽  
pp. 23-30 ◽  
Author(s):  
Heping Zhao ◽  
Feike Zhang ◽  
Jun Chai ◽  
Jianping Wang

The present study aimed to investigate the effect of probiotic lactic acid bacteria (LAB) addition on Listeria monocytogenes translocation and its toxin listeriolysin O (LLO), proinflammatory factors, immune organ indexes and serum immunoglobulins in farmed rabbits. Five treatments included negative control (NC), positive control (PC) with L. monocytogenes infection and supplemental LAB at 3.0 × 10<sup>6 </sup>(low-LAB, L-LAB), 3.0 × 10<sup>8</sup> (medium-LAB, M-LAB) and 3.0 × 10<sup>10 </sup>(high-LAB, H-LAB) CFU/kg of diet, respectively. The LAB was a mixture of equal amounts of Lactobacillus acidophilus (ACCC11073), Lactobacillus plantarum (CICC21863) and Enterococcus faecium (CICC20430). A total of 180 weaned rabbits (negative for L. monocytogenes) were randomly assigned to 5 groups with 6 replicates of 6 rabbits each in response to the 5 treatments. L. monocytogenes infection occurred on the first day of feeding trial and dietary LAB supplementation lasted for 14 days. The results showed that on days 7 and 14 post administration, L. monocytogenes in caecum, liver, spleen and lymph nodes was reduced in M-LAB and H-LAB compared to PC (P &lt; 0.05), and linear and quadratic reducing trends were found in liver on day 7 (P ≤ 0.002). On day 14, mucosa LLO mRNA expression and serum TNFα, IL1β and IFNγ were reduced in the three LAB treatments (P &lt; 0.05), and linear and quadratic trends were found on TNFα and IL1β (P ≤ 0.025); indexes of thymus and spleen, serum IgA and IgG were increased in the LAB treatments (P &lt; 0.05). It is concluded that LAB can be used to alleviate L. monocytogenes infection and to improve the immune function of farmed animals.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Eun Yeong Jang ◽  
Yejin Ahn ◽  
Hyung Joo Suh ◽  
Ki-Bae Hong ◽  
Kyungae Jo

Constipation is a chronic disease caused by infrequent, inadequate, and difficult bowel movements. The present study aimed to evaluate the potential laxative effect of maltooligosaccharide (MOS) on loperamide-induced constipation in a rat model. In vitro experiments were conducted to evaluate the effect of MOS on the growth of lactic acid bacteria. Moreover, to examine the effect of MOS administration on Sprague-Dawley (SD) rats with loperamide-induced constipation, the drinking water for the rats was supplemented with 10% or 15% of MOS for 14 days, and, thereafter, the improvement in constipation was assessed. For this, the rats were divided into five groups: normal (Nor), loperamide-induced constipated (Con), positive control (15% of dual-oligosaccharide (DuO-15)), 10% MOS treated (MOS-10), and 15% MOS-treated (MOS-15). In an in vitro test, MOS treatment promoted the growth of lactic acid bacteria except Lactobacillus bulgaricus. Treatment with higher MOS dose relieved constipation in rats by improving the fecal pellet and water content. Furthermore, in the high MOS dose group, the cecal short-chain fatty acid levels significantly increased compared to those in the control group (P<0.001). MOS treatment also improved the mucosal thickness as well as mucin secretion and increased the area of intestinal Cajal cells compared to that in the control group (P<0.001). These findings suggest that MOS relieves constipation and has beneficial effect on the gastrointestinal tract, and, therefore, it can be used as an ingredient in functional foods for treating constipation or improving intestinal health.


Agric ◽  
2019 ◽  
Vol 31 (1) ◽  
pp. 53-66
Author(s):  
Samsul Rizal ◽  
Julfi Restu Amelia ◽  
Suharyono A S

Sinbiotic drinks have a very acidic taste, so it is necessary to add sucrose solution to get the best taste. This study aims to determine the effect of adding 65% (v/v) sucrose solution to changes in antibacterial activity of green grass jelly synbiotic drinks during storage in cold temperatures. The finished green grass jelly synbiotic product was given two different treatments, namely the product without the addition of sucrose solution and product with the addition of 10% (v/v) of 65% (b/v) sucrose solution. The product was stored for 28 days at a cold temperature of ± 10oC. Observations were carried out every 7 days for antibacterial activity, pH, total acid, and total lactic acid bacteria. Antibacterial activity was evaluated using the agar diffusion method against pathogenic bacteria including Staphylococcus aureus, Salmonella sp., Bacillus cereus, and Eschericia coli. The results showed that the antibacterial activity, pH, and total lactic acid bacteria of green grass jelly synbiotic drinks both without and with the addition of 65% (b/v) sucrose as much as 10% (v/v) reduced during storage at cold temperatures, while total acid increases. There was no significant difference between the antibacterial activity and the characteristics of the green grass jelly synbiotic drink given 65% sucrose solution and without the addition of 65% sucrose solution. Thus the study concluded that the addition of 65% sucrose solution to increase the preference for the product did not significantly affect the change in antibacterial activity of the green grass jelly synbiotic beverage during storage in cold temperatures.


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