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

Abstract

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.

Acute Hepatopancreatic Necrosis Disease (AHPND): Virulence, Pathogenesis and Mitigation Strategies in Shrimp Aquaculture

“…The results showed that 3 among 19 isolated LAB strains have the highest antagonizing ability against AHPND V. parahaemolyticus strain in vitro, generating inhibition zones ranging from 18 to 20 mm in diameter. In addition, the shrimps fed with LAB supplemented diets displayed significantly higher survival (approximately 80%) upon AHPND V. parahaemolyticus challenge [ 102 ]. Recently, Wang et al (2020) demonstrated that the natural product amicoumacins A purified from the cell-free supernatant of Bacillus subtilis BSXE-1601 strain harboured acillibactin, fengycin, surfactin, bacilysin and subtilosin A, which are responsible for both in vitro and in vivo anti- Vibrio activity against AHPND-causing V. parahaemolyticus strain in L. vannamei [ 103 ].…”

Effects of Feed Mixed with Lactic Acid Bacteria and Carbon, Nitrogen, Phosphorus Supplied to the Water on the Growth and Survival Rate of White Leg Shrimp (Penaeus vannamei) Infected with Acute Hepatopancreatic Necrosis Disease Caused by Vibrio parahaemolyticus

“…The application of biological methods is effective to limit drug resistance of pathogens, and usage in disease prevention is increasingly popular. Previous studies showed the effectiveness of using LAB to limit harmful effects of this disease, such as the study of [ 8 ] using L. plantarum T8 and T13 bacteria and the study of [ 18 ] using heat-killed L. plantarum strain L137. Similarly, L. plantarum , L. fermentum , and P. pentosaceus supplementation of the present study demonstrated a strong resistance against V. parahaemolyticus .…”

“…L. plantarum , L. fermentum , and p. pentosaceus strains [ 8 ] that have the ability to inhibit the AHPND [ 8 ] were cultured in 100 mL of MRS broth medium (Darmstadt, Merck) supplemented with 1.5% NaCl for 48 h. Shortly after this, bacteria density was determined by OD measurement with an optical density of 1 ± 0.025, centrifuged at a rate of 7000 revolutions within 5 min, and rinsed thrice with sterile saline, and each bacteria strain was properly mixed into the commercial feed (CP brand name) containing 40% crude protein to reach a density of 10 8 CFU/g, then coated with squid oil. Feed was put in labeled plastic bags and stored at a maximum temperature of 4 °C to be used for seven days.…”

“…The experiment was a completely randomized design including four treatments and with three replicates for each. In the control treatment, shrimp were fed a normal diet, without containing LAB; for LAB1, LAB2, and LAB3 treatments, shrimp were fed with feed containing L. plantarum, L. fermentum , and Pediococcus pentosaceus at a density of 10 8 Colony Forming Units per gam (CFU/g), respectively [ 8 ]. The experiment was arranged in 1000 L plastic tanks with a density of 100 shrimp/tank and a shrimp size of 3 g/shrimp.…”

“…Lactic acid bacteria are widely used in human and animal probiotics to stimulate digestion and prevent a number of bacterial diseases. LAB have been selected as a supplement to aquatic animal feed because of many benefits, such as competing to eliminate pathogenic bacteria [ 4 ], supplying nutrients and digestive enzymes [ 7 ], and other benefits such as strengthening the immune system against pathogenic bacteria [ 4 ] and antiviral activities [ 8 , 9 , 10 ]. In the present study, LAB strains significantly reduced the mortality of shrimp challenged with V. parahaemolyticus from 70% in the positive controls to 11%, 22%, and 28% in the treatments administered the LAB of Lactobacillus plantarum, Lactobacillus fermentum , and Pediococcus pentosaceus , respectively.…”