Importantly, two fish pathogens, namely Aeromonas and Vibrio showed a higher abundance in without SL001-supplemented group (17.6 and 15.1%, respectively) than that in SL001-supplemented group (12.9 and 0.3%, respectively) (Figure 6C and Supplementary Figure S3C). LSZ gene expression in SL001-fed grass carps was notably upregulated at 6 hpi and then significantly down-regulated at 12 hpi (Figures 8C,F). In addition, the expression of IgM in the SL001-supplemented group was evidently down-regulated at 12 hpi (Figure 8E). J. Zhejiang Univ. The editor and reviewers' affiliations are the latest provided on their Loop research profiles and may not reflect their situation at the time of review. doi: 10.1016/j.foodhyd.2018.05.024, Yi, Y., Zhang, Z., Zhao, F., Liu, H., Yu, L., Zha, J., et al. Microbiol.  showed that TNF receptor-associated factor 6 (TRAF6) was crucial not only in interleukin 1 (IL-1) and CD40 signaling, but also, surprisingly, in LPS signaling and was also essential for prenatal and postnatal survival. Today 16, 203–218. Isolation and partial characterization of lactic acid bacteria from the gut microbiota of marine fishes for potential application as probiotics in aquaculture. 80, 540–545. In general, the dominant phyla (abundance > 10%) in both groups were Firmicutes, Proteobacteria, and Fusobacteria. 68, 557–567. Values represented mean ± SEM. As preceding description of Yi et al. (2018). Independent-Samples t-test and Least-Significant Difference test were used to calculate significant differences. Encapsulation of P. pentosaceus Li05 in an alginate-gelatin microgels significantly enhanced their viability under different conditions (Yao et al., 2018). A comparison of the two groups revealed that the control group had a lower expression than the experimental group, and the difference was significant () and very significant () at 3 dpi and 7 dpi, respectively. To this end, we evaluated the body condition change, caecum flora count, and the expression of TLR pathway genes and inflammatory factor genes in the spleen and caecum of S. enteritidis-infected chickens, which had been fed a diet with or without P. pentosaceus. doi: 10.1016/j.fsi.2018.07.031, DiMaggio, M. A., Ohs, C. L., Broach, J. S., and Sink, T. D. (2014). SL001 was incubated in MRS liquid medium at 37°C for 24 h under anaerobic conditions. Rep. 5:9336. doi: 10.1038/srep09336, Freddo, A. M., Shoffner, S. K., Shao, Y., Taniguchi, K., Grosse, A. S., Guysinger, M. N., et al. Values represented mean ± SEM. Through this research, we can speculate that the P .pentosaceus can not completely eliminate the S. enteritidis infection and it just inhibited the bacterial growth. AKP is an extracellular enzyme, which could hydrolyzes phosphate group within various organic compounds like proteins, nucleic acid (El-Ebiarie, 2012). Fish Shellfish Immunol. Sequencing was performed by Wuhan Nextomics Biotechnology, Co., Ltd., with Illumina MiSeq system (Illumina, United States). Bioinformatics 26, 2460–2461. In the past many years, control strategies on fish pathogens relied mostly on the application of chemicals, such as antibiotics and disinfectants. The gene expression levels of immune-related cytokines in (A) liver and (B) spleen were measured by qRT-PCR. doi: 10.1128/Aem.01821-12, Wu, J. Y., Jiang, X. T., Jiang, Y. X., Lu, S. Y., Zou, F., and Zhou, H. W. (2010). 85, 42–50. Microbiol. The immune response is a complex process involving the innate immune system, whose activation is indicated by the release of,inflammatory factors, such as IFN-β, TNF-α, IL6, and IL8, which play an important role in this process. These 3 strains were identified as Pediococcus acidilactici VKU2, P. acidilactici IAH-5 and P. pentosaceus DHR005 by 16S rRNA gene sequencing. The shared microbiome, discovered in both groups, was identified and comprised 239 OTUs; 38 OTUs were unique in SL001-supplemented group and 164 OTUs were unique in without SL001 supplemented group (Figure 6E). Data supporting the findings is contained within the manuscript. Pediococcus pentosaceus is more sensitive than P. acidilactici to antibiotics except for chlortetracycline, chloramphenicol, erythromycin, and streptomycin. Pediococcus acidilactici and Pediococcus pentosaceus are the most common species associated with opportunistic infections affecting compromised hosts. LAB strains that have been used for fish pathogens control usually include the genera Lactobacillus, Leuconostoc, Streptococcus, and Pediococcus (Perez-Ramos et al., 2018). Materials and Methods. Pediococcus pentosaceus is a Gram-positive coccus which had probiotics properties. Efficient digestion and absorption of nutrients by the intestine require a very large apical surface area, a feature that is enhanced by the presence of villi (Freddo et al., 2016). Pediococci are resistant to vancomycin (Van). Molecular cloning and functional characterisation of NLRX1 in grass carp (Ctenopharyngodon idella). Feeding with SL001 supplemented diet could significantly enhance the growth rate (P < 0.05) and markedly affect gut microbiota structure of grass carps, resulting in reduced potential pathogens and increased potential probiotics. 9:2607. doi: 10.3389/Fmicb.2018.02607, Keywords: Pediococcus pentosaceus, antibacterial activity, grass carps, gut microbiota, fish immunity, growth rate, Citation: Gong L, He H, Li D, Cao L, Khan TA, Li Y, Pan L, Yan L, Ding X, Sun Y, Zhang Y, Yi G, Hu S and Xia L (2019) A New Isolate of Pediococcus pentosaceus (SL001) With Antibacterial Activity Against Fish Pathogens and Potency in Facilitating the Immunity and Growth Performance of Grass Carps. Most of the birds showed clinical symptoms at 12 hpi, which included depression, decreased ingestion, diarrheal disease, being afraid of the cold, and dyspnea. The expression exhibited a rising trend in the experimental group, which was highest at 7 dpi. Lactic acid bacteria (LAB) and Bacillus species are among the most commonly used probiotic candidates (Cao et al., 2011; Banerjee and Ray, 2017; Alonso et al., 2018; Yi et al., 2018). Two grass carps’ gut were stored in 4% paraformaldehyde fix solution and sent for histological analysis. The control group had the highest temperature (42.2°C) at 1 dpi and then showed continuous decline, until it reached 41°C at 3 dpi. Previous report demonstrated that the SOD enhanced humoral and cellular immunity in animals and improved disease resistance (Picchietti et al., 2009). Then, sterile oxford cups were placed on the plates dried for 30 min on vertical flow clean cabinet. Probiotics Antimicrob. Among the four inflammatory factor genes, expression of IFN-β, TNF-a, and IL6 genes exhibited the same trends in those two tissues as over the time period at which they were evaluated, while the IL8 gene showed different trends in the tissues examined. The formula of ∆∆Ct was followed. The contents of the caecum (0.2 g) were added into 1.8 ml peptone and mixed. (2015). Their intrinsic vancomycin resistance led to their recognition in clinical microbiology in the late 1980's, having been previously confused with oral streptococci and enterococci (8,13,31).Pediococci are catalase-negative, gram-positive cocci, arranged in pairs and tetrads, whose colony morphologies resemble oral streptococci on blood agar. bacteria as probiotics in gilthead sea bream (Sparus aurata, L.) larvae: effects on growth performance and digestive enzyme activities. Evid. The flora in the caecum exhibited “rising-declining” trends, and the gene (TLR4, MyD88, TRAF6 NF-κB, IFN-β, TNF-a, IL6, and IL8) expression pattern was different between the experimental and control group. Impact Factor 4.235 | CiteScore 6.4More on impact ›, Interactions Between Diets, Gut Microbiota and Host Metabolism Amplifications were performed in ABI GeneAmp® 9700 (Applied Biosystems, United States) with initial denaturation at 95°C for 3 min, 28 cycles of 30 s at 95°C, 30 s at 58°C, 45 s at 72°C and final extension at 72°C for 10 min. Based Complement. caused the downregulation of two pro-inflammatory cytokine genes and activated the host’s immune system, so that the significant upregulation of LSZ and C3 (involved in non-specific immunity) and the IgM (involved in specific immunity). In conclusion, P. pentosaceus SL001 which could enhance immunity and promoter growth rate of grass carps, is prospective to be used as a dietary probiotic in freshwater fish aquaculture.