Evaluation of the safety, immunogenicity and protective effect of an attenuated Pseudomonas plecoglossicida strain ΔgacS as the live vaccine for the large yellow croaker (Larimichthys crocea).

Pseudomonas plecoglossicida is one of most important pathogenic bacterial species in large yellow croaker and several other commercially valuable fish species. In our previous study, a GacS deficient mutant (ΔgacS) was constructed and its virulence showed substantially attenuated. In present study, the safety, immunogenicity and protective effect of the ΔgacS were evaluated in large yellow croaker as a live-attenuated vaccine candidate. It was shown that the ΔgacS strain exhibited good safety to large yellow croaker and there was no mortality or clinical symptoms observed in all fish that infected by ΔgacS strain with the doses range from 2 × 105～107 CFU per fish via intraperitoneal injection (IP) or immersion (IM), and almost all bacteria were cleaned up in the spleen of the fish at 14-day post infection. Specific antibodies could be detected at 7-day and 14-day post infection by direct agglutination method, and the valences of antibodies and bactericidal activities of the serum were significant increased with vaccination doses and vaccination time. Moreover, the expressions of some molecules and cytokines involved in specific immune responses were detected in the ΔgacS strain immunization group and control group. After challenged by the wild-type (WT) strain XSDHY-P, the relative percentage survival (RPS) showed highly correlated with the immunized dosage regardless of vaccination methods. It showed that the RPS of the IP groups were 39.47 %, 57.89 %, 71.05 % with the immune dosage in a descending order, respectively, and the RPS of the IM groups were 26.31 %, 36.84 %, 76.31 % with the immune dosage in a descending order, respectively. In summary, the ΔgacS strain exhibited safety and good protective effect to large yellow croaker and was a potential live vaccine candidate.

Advances in valorization of sweet potato peels: A comprehensive review on the nutritional compositions, phytochemical profiles, nutraceutical properties, and potential industrial applications.

During food production, food processing, and supply chain, large amounts of food byproducts are generated and thrown away as waste, which to a great extent brings about adverse consequences on the environment and economic development. The sweet potato (Ipomoea batatas L.) is cultivated and consumed in many countries. Sweet potato peels (SPPs) are the main byproducts generated by the tuber processing. These residues contain abundant nutrition elements, bioactive compounds, and other high value-added substances; therefore, the reutilization of SPP holds significance in improving their overall added value. SPPs contain abundant phenolic compounds and carotenoids, which might contribute significantly to their nutraceutical properties, including antioxidant, antimicrobial, anticancer, prebiotic, anti-inflammatory, wound-healing, and lipid-lowering effects. It has been demonstrated that SPP could be promisingly revalorized into food industry, including: (1) applications in diverse food products; (2) applications in food packaging; and (3) applications in the recovery of pectin and cellulose nanocrystals. Furthermore, SPP could be used as promising feedstocks for the bioconversion of diverse value-added bioproducts through biological processing.

Transcriptome analysis of Cryptocaryon irritans tomont responding to Bacillus licheniformis treatment.

Cryptocaryon irritans is a ciliated obligate parasite that causes cryptocaryonosis (white spot disease) and poses great threat to marine fish farming. In recent years, the use of probiotics protects fish from pathogens, which has been identified as the sustainable and environmentally friendly tool to maintain the health and well-being of the host. Accordingly, Cryptocaryon irritans tomont and probiotic Bacillus strain (B.licheniformis, previously isolated from aquaculture water) were co-cultured to detect whether B. licheniformis has anti-C. irritants effect. The result showed that during 4-day incubation, B. licheniformi with 1 × 107 CFU/mL and 1 × 108 CFU/mL concentration effectively inhibited the incubation of C. irritans tomont, indicating that B. licheniformi could inhibit the transformation from reproductive tomont to infective theront of C. irritans. Later, C. irritans samples in the control (without B. licheniformi supplementation) and 1 × 107 CFU/mL B. licheniformi treatment group were sent for transcriptome analysis. Compare with the control group, a total of 3237 differentially expressed genes were identified, among which 626 genes were up-regulated and 2611 genes were down-regulated in 1 × 107 CFU/mL B. licheniformi group. Further Kyoto Encyclopedia of Genes and Genomes pathways analysis showed that anti-C. irritans mechanism of B. licheniformi was mainly involved in the energy metabolism (carbon metabolism, oxidative phosphorylation, biosynthesis of amino acids), transcription and translation (Ribosomes, spliceosomes, RNA transport, etc), lysosome-based degradation (lysosome, phagosome, protein processing in endoplasmic reticulum) and PI3K-Akt pathways. Our study findings raised the possibility of using marine microorganism B. licheniformi in handling aquaculture associated pathogen C. irritans, and preliminarily clarified the molecular mechanism.

Transcriptome profiling and differential expression analysis of altered immune-related genes in goldfish (Carassius auratus) infected with Aeromonas hydrophila.

Goldfish (Carassius auratus) have been employed as a model organism to investigate the innate immune system and host-pathogen interactions. A Gram-negative bacterium called Aeromonas hydrophila has been found to cause mass mortality due to infection in a wide variety of fish species in the aquatic system. In this study, damages in Bowman's capsule, inflammatory tubular (proximal and distilled convoluted) structure, and glomerular necrosis were observed in A. hydrophila-infected head kidney of goldfish. To increase the better understanding of immune mechanisms of host defense against A. hydrophila, we performed a transcriptome analysis in head kidney of goldfish at 3 and 7 days of post-infection (dpi). Comparing to the control group, 4638 and 2580 differentially expressed genes (DEGs) were observed at 3 and 7 dpi, respectively. The DEGs were subsequently enriched in multiple immune-related pathways including Protein processing in endoplasmic reticulum, Insulin signaling pathway, and NOD-like receptor signaling pathway. The expression profile of immune-related genes such as TRAIL, CCL19, VDJ recombination-activating protein 1-like, Rag-1, and STING was validated by qRT-PCR. Furthermore, the levels of immune-related enzyme (LZM, AKP, SOD, and CAT) activities were examined at 3 and 7 dpi. The knowledge gained from the current study will be helpful for better understanding of early immune response in goldfish after A. hydrophila challenge, which will aid in future research on prevention strategies in teleost.

Nigericin treatment activates endoplasmic reticulum apoptosis pathway in goldfish kidney leukocytes.

Nigericin has been reported to induce apoptosis and pyroptosis in mammalian models. However, the effects and mechanism underlying the immune responses of teleost HKLs induced by nigericin remain enigmatic. To decipher the mechanism after nigericin treatment, the transcriptomic profile of goldfish HKLs was analyzed. The results demonstrated that a total of 465 differently expressed genes (DEGs) with 275 up-regulated and 190 down-regulated genes were identified between the control and nigericin treated groups. Among them, the top 20 DEG KEGG enrichment pathways were observed including apoptosis pathways. In addition, the expression level of selected genes (ADP4, ADP5, IRE1, MARCC, ALR1, DDX58) by quantitative real-time PCR showed a significant change after treatment with nigericin, which was generally identical to the expression patterns of the transcriptomic data. Furthermore, the treatment could induce cell death of HKLs, which was confirmed by LDH release and annexin V-FITC/PI assays. Taken together, our results support the idea that nigericin treatment might activate the IRE1-JNK apoptosis pathway in goldfish HKLs, which will provide insights into the mechanisms underlying HKLs immunity towards apoptosis or pyroptosis regulation in teleosts.

Organocatalytic allylic alkylation of alkyne-substituted MBH carbonates: access to quaternary carbon-containing 1,4-enynes.

A DABCO-catalyzed allylic alkylation of tertiary propargylic alcohol-derived MBH carbonates with nitromethane was developed. A series of substituted 1,4-enynes with an all-carbon quaternary stereocenter were efficiently obtained in moderate to high yields. The synthetic utility of the product was demonstrated by facile synthesis of 1,4-enyne-embedded 2-pyrrolidinones.

Electronic and magnetic properties of charged point defects in monolayer CrI3.

The two-dimensional magnetic material CrI3 has gained considerable attention owing to its promising applications in photoelectric and spin-related devices. Recently, various structural defects in CrI3 have been identified; however, the charge states of these defects have been mainly ignored. Here, we report on an investigation of the charged defects in monolayer CrI3, focused on the electronic and magnetic properties of the five most stable point defects using first-principles calculations. For positively charged I vacancies and negatively charged Cr vacancies, a blue- and red-shift of defect states near the Fermi level can be observed because of the atom relaxation. Our results also indicate that, among the five defects, the Cr interstitial defect has the smallest ionization energy of 0.34 eV, which makes its ionization easiest. Furthermore, a 0.2 µB enhancement of the magnetic moment on the nearest Cr atom can be found for the I vacancy and Cr interstitial defect. The investigation contributes to the atomic-scale comparison and understanding of the charged defects of monolayer CrI3.

Effect of copper sulphate on Cryptocaryon irritans based on metabolome analysis.

Cryptocaryon irritans is one of the most harmful marine parasites in mariculture. Copper sulphate is often used to kill parasites and the influence of copper sulphate on the tomont stage of C. irritans was explored in this study. The results showed that excystment rate was not significantly affected when tomonts were exposed to 5 mg/L (76.7%) and 10 mg/L (78.9%) of copper sulphate for 3 h. However, excystment rate was significantly inhibited when exposed to 15 mg/L (33.3%) for 3 h and 5 mg/L (28.9%), 10 mg/L (33.3%) and 15 mg/L (33.3%) for 6 h. After treatment with high concentrations of copper sulphate, the interior of the tomonts was fuzzy under the microscope, and the division process could not be observed. Metabolomic results combined with preliminary transcriptome analysis results showed that the tomonts were induced to produce linoleate, riboflavin, inositol and other substances under the stress of Cu2+ , which affected the antioxidant mechanism of the body. Using MDA content determination and antioxidant enzyme activity analysis, copper sulphate was found to cause oxidative damage to tomonts by affecting the generation of metabolites, leading to the death of tomonts.

Spatial filtering of Zeeman sub-states in an atomic fountain.

In an atomic fountain, atoms in motion can be spatially separated into discrete Zeeman sub-states by magnetically induced Stern-Gerlach effect. With resonant light pulses acting as a shutter, specific states are selected for subsequent experiments. Such separation-selection process in atomic optics is the analogue of a spatial filter in physical optics which selects and purifies the modes of light. This technique is demonstrated by injecting a pulsed current in a circular coil around a vertical atomic fountain, separating the pre-cooled Rubidium atoms by a distance of centimeters in between, and filtering each single sub-state with block pulses. The filtered atoms after the process is highly purified in the desired sub-state. The apparatus of the atomic spatial filter is adaptable in atomic optics and can be integrated into the high-vacuum chamber of an atomic fountain.

An overview of the nutritional profile, processing technologies, and health benefits of quinoa with an emphasis on impacts of processing.

Consumers are becoming increasingly conscious of adopting a healthy lifestyle and demanding food with high nutritional values. Quinoa (Chenopodium quinoa Willd.) has attracted considerable attention and is consumed worldwide in the form of a variety of whole and processed products owing to its excellent nutritional features, including richness in micronutrients and bioactive phytochemicals, well-balanced amino acids composition, and gluten-free properties. Recent studies have indicated that the diverse utilization and final product quality of this pseudo-grain are closely related to the processing technologies used, which can result in variations in nutritional profiles and health benefits. This review comprehensively summarizes the nutritional properties, processing technologies, and potential health benefits of quinoa, suggesting that quinoa plays a promising role in enhancing the nutrition of processed food. In particular, the effects of different processing technologies on the nutritional profile and health benefits of quinoa are highlighted, which can provide a foundation for the updating and upgrading of the quinoa processing industry. It further discusses the present quinoa-based food products containing quinoa as partial or whole substitute for traditional grains.

Contribution of starch to the flavor of rice-based instant foods.

Increased consumption of instant foods has led to research attention, especially rice-based instant foods. Starch, one of the most important components of rice, significantly affects food quality. However, the mechanisms by which starch contributes to rice-based instant foods flavor are poorly understood in many cases. The review aims to describe the common mechanisms by which starch contributes to food flavor, including participating in flavor formation, and affecting flavor release throughout starch multiscale structure: particle morphology, crystal structure, molecular structure. Five specific examples of rice-based instant foods were further analyzed to summarize the specific contribution of starch to flavor, including instant rice, fermented rice cake, rice noodles, fried rice, and rice dumplings. During foods processing, reducing sugars produced by heating or enzymatic hydrolysis of starch participate in Maillard reaction, caramelization and thermal degradation, which directly or indirectly affect the formation of flavor compounds. In addition, adsorption by granules, encapsulation by retrograded V-type crystal, and controlled release by starch gel all contribute to rice-based instant food flavor qualities. These mechanisms jointly contribute to flavor compounds formation and release. Proper theoretical application and improved processing methods are needed to promote the high-quality, mechanization, and automation of rice-based instant foods production.

Transcriptome profiling and differential expression analysis of the immune-related genes during the acute phase of infection with Photobacterium damselae subsp. damselae in silver pomfret (Pampus argenteus).

Silver pomfret has been widely cultured in China due to its high economic value. Photobacterium damselae subsp. damselae (PDD) is a Gram-negative bacterium that has been shown to infect many fish species. To increase knowledge of the molecular mechanisms of the host defense against PDD, we conducted transcriptome analysis of head kidney in silver pomfret at 24 h and 72 h post-infection (hpi) via Illumina sequencing. The de novo assembly resulted in the identification of 79,063 unigenes, with 59,386 (75.11%) successfully annotated in public databases (NR, NT, KO, Swiss-Prot, Pfam, GO, and KOG databases). Comparison of gene expression profiles between PBS-injected fish (sham control) and PDD-challenged fish revealed 329 and 570 differentially expressed genes (DEGs) were screened at 24 hpi and 72 hpi, respectively. The DEGs were enriched in multiple immune-related pathways such as Hepatitis C, Gastric acid secretion, CAMs and Leukocyte transendothelial migration pathways, Primary immunodeficieny, ECM-receptor interaction, PI3K-Akt signaling pathway. The data obtained in the present study offers valuable information for acute immune response of silver pomfret challenged with PDD, which will facilitate further investigations on strategies against Photobacterium spp. infection in teleosts.

An edible molecularly imprinted material prepared by a new environmentally friendly deep eutectic solvent for removing oxalic acid from vegetables and human blood.

A novel deep eutectic solvent-magnetic molecularly imprinted polymer (DES-MMIP) for the specific removal of oxalic acid (OA) was prepared by an environmentally friendly deep eutectic solvent, consisting of betaine, citric acid, and glycerol, which acted as the functional monomer for polymerization. The structure and morphology of DES-MMIPs were studied by X-ray diffraction, scanning and transmission electron microscopy, thermal gravimetric analysis, Fourier transform infrared spectroscopy, and vibrating sample magnetometer. DES-MMIPs had a core-shell structure, with magnetic iron oxide as the core, and showed good thermal stability and high adsorption capacity (18.73 mg/g) for OA. The adsorption process of OA by DES-MMIPs followed the pseudo-second-order kinetic model and Langmuir isotherm model. DES-MMIPs had significant selectivity for OA and their imprinting factor was 3.26. When applied to real samples, high performance liquid chromatography analysis showed that DES-MMIPs could remove OA from both spinach and blood serum. These findings provide potential methods for removal of OA from vegetables and for specific removal of OA in renal dialysis.

Outbreak of Cryptocaryon irritans infection in silver pomfret Pampus argenteus cultured in China.

Silver pomfret Pampus argenteus is a major cultivated marine fish species with a high market value. In summer 2021, Cryptocaryon irritans, a ciliate parasite, infected the cultured silver pomfret in aquaculture ponds in Ningbo, Zhejiang Province, China. The symptoms of infected fish include white spots on the skin and fins, increased body surface mucus, loss of appetite, irritability, and shedding of scales. After collecting white spots from moribund fish, the 18S ribosomal RNA sequence of the pathogen on the fish skin was amplified by PCR; phylogenetic analysis showed that it was closely related to C. irritans strains from Ningde, Fujian, China. Four groups of silver pomfret were tested in an artificial infection experiment over the course of 72 h, consisting of 3 infected groups (1600, 4000, and 8000 theronts fish-1) and 1 healthy group. White spots were observed on the skin and fins of the infected fish, but not on their gills. Samples were taken from the gills, liver, kidney, and spleen of both infected and healthy fish and were compared to evaluate any significant histopathological differences. As the dose of infection increased, symptoms became more pronounced. At 72 h, mortality rates were 8.3, 50, and 66.7% for the 3 different concentrations, respectively. The median lethal concentration was calculated to be 366 theronts g-1 at 72 h, 298 theronts g-1 at 84 h, and 219 theronts g-1 at 96 h. This study emphasizes the importance of developing early diagnosis methods and appropriate prevention strategies to decrease the impact of C. irritans infection in the silver pomfret aquaculture industry.

Transcriptome analysis to elucidate the toxicity mechanisms of fenvalerate, sulfide gatifloxacin, and ridomil on the hepatopancreas of Procambarus clarkii.

Most antibiotics, insecticides, and other chemicals used in agricultural and fishery production tend to persist in the environment. Fenvalerate, sulfide gatifloxacin, and ridomil are widely used in aquaculture as antibacterial, antifungal, and antiparasitic drugs; however, their toxicity mechanism remains unclear. Thus, we herein analyzed the effects of these three drugs on the hepatopancreas of Procambarus clarkii at the transcriptome level. Twelve normalized cDNA libraries were constructed using RNA extracted from P. clarkii after treatment with fenvalerate, sulfide gatifloxacin, or ridomil and from an untreated control group, followed by Kyoto Encyclopedia of Genes and Genomes pathway analysis. In the control vs fenvalerate and control vs sulfide gatifloxacin groups, 14 and seven pathways were significantly enriched, respectively. Further, the effects of fenvalerate and sulfide gatifloxacin were similar on the hepatopancreas of P. clarkii. We also found that the expression level of genes encoding senescence marker protein-30 and arylsulfatase A was downregulated in the sulfide gatifloxacin group, indicating that sulfide gatifloxacin accelerated the apoptosis of hepatopancreatocytes. The expression level of major facilitator superfamily domain containing 10 was downregulated, implying that it interferes with the ability of the hepatopancreas to metabolize drugs. Interestingly, we found that Niemann pick type C1 and glucosylceramidase-ß potentially interact with each other, consequently decreasing the antioxidant capacity of P. clarkii hepatopancreas. In the fenvalerate group, the downregulation of the expression level of xanthine dehydrogenase indicated that fenvalerate affected the immune system of P. clarkii; moreover, the upregulation of the expression level of pancreatitis-associated protein-2 and cathepsin C indicated that fenvalerate caused possible inflammatory pathological injury to P. clarkii hepatopancreas. In the ridomil group, no pathway was significantly enriched. In total, 21 genes showed significant differences in all three groups. To conclude, although there appears to be some overlap in the toxicity mechanisms of fenvalerate, sulfide gatifloxacin, and ridomil, further studies are warranted.

Switchable electronic and enhanced magnetic properties of CrI3 edges.

Owing to its novel electronic and magnetic properties, two-dimensional CrI3 has great potential in the application of spintronic devices. However, as an inevitable line defect, the properties of the edges of CrI3 remain elusive. Here, via first-principles calculations with spin-orbit coupling, we investigated the thermodynamic stabilities, electronic and magnetic properties of thirteen CrI3 edges with different structures. We showed that zigzag edges are more stable than armchair edges, and a CrI3 nanoribbon can be either metallic or insulating depending on its chemical growth conditions. The edge stability and associated electronic properties can be understood in terms of the octahedron ligand field and electron counting model. In most cases, both the magnetic moment and Curie temperature can be enhanced by edges, which are in startle contrast to the surfaces of three-dimensional ferromagnetic materials, where a magnetic dead layer is often observed.

Median Effective Dose of Lidocaine for the Prevention of Pain Caused by the Injection of Propofol Formulated with Medium- and Long-Chain Triglycerides Based on Lean Body Weight.

OBJECTIVE: To determine the median effective dose (ED50) of prophylactic intravenous lidocaine for the prevention of propofol medium-chain triglyceride/long-chain triglyceride (MCT/LCT) emulsion injection pain. DESIGN: Prospective trial, Dixon up-and-down sequential method. SETTING: Operating room of a single hospital. PATIENTS: Thirty patients aged 18-65 years with American Society of Anesthesiologists (ASA) status I or II who were scheduled for elective surgery under general anesthesia (GA) were included. INTERVENTIONS: The initial dose of prophylactic lidocaine before propofol MCT/LCT emulsion injection was set at 0.5 mg/kg lean body weight (LBW). The lidocaine dose was adjusted according to the degree of patients' injection pain using the Dixon up-and-down sequential method. MEASUREMENTS: The ED50 and 95% confidence intervals (CIs) of lidocaine were calculated using the Dixon-Massey formula. Vital signs and adverse effects were recorded. In the postanesthesia care unit (PACU), patients were asked if they recalled feeling any injection pain with visual analog scale (VAS) evaluation. RESULTS: The ED50 of lidocaine for the prevention of propofol MCT/LCT emulsion injection pain was 0.306 mg/kg LBW (95% CI, 0.262-0.357 mg/kg LBW). No adverse reactions to lidocaine occurred. In the PACU, 90.9% of patients who experienced injection pain recalled this pain (VAS score, 2.8±1.8). CONCLUSIONS: Prophylactic intravenous lidocaine (0.306 mg/kg LBW) effectively prevented propofol MCT/LCT emulsion injection pain in 50% of patients scheduled for elective surgery under GA with no adverse reaction occurring.

Bacterial Flora in the Gill Tissues and Intestinal Tracts of Male and Female Chinese Mitten Crabs (Eriocheir sinensis) with Different Diets in a Mud Pond.

The Chinese mitten crab, Eriocheir sinensis, is an economically valuable aquaculture species. Prior to sale, farmed crabs are often fattened with pellet feed or wild fish. In this study, PacBio Sequel sequencing was used to determine the bacterial flora in the intestinal tracts and gill tissues of male and female E. sinensis fed with various diets. The flora was then compared with the microorganisms found in environmental samples. The results showed that Proteobacteria was the dominant phylum in both tissue and environmental samples. The relative abundances of Proteobacteria in the water grass surface flushing samples and water grass samples were the highest, at up to 95.68% and 67.85%, respectively. Beyond that, Bacteroidetes, Firmicutes, and Tenericutes were the dominant phyla (>1%) in the intestinal samples, whereas Bacteroidetes and Actinobacteria were the dominant phyla in the gills. In addition, different environment samples contained diverse bacterial phyla, indicating some differences in the community composition between the different sample groups. Heat map clustering and principal coordinate plot analyses indicated that intestinal samples, crab gill samples, and environmental samples clustered together, respectively. Furthermore, an unweighted pair-group method with arithmetic mean technique confirmed that the intestinal and gill samples of crabs with different diets separately clustered together, suggesting the microbial assemblages of the same tissues share a greater similarity than those from crabs of different sex and eating different diets. What's more, biomarker bacteria (LDA ≥ 4) from the different groups were identified. Pathogenic agents from the genus Aeromonas were abundant in the intestinal samples of crabs fed with pellet feed, and Vibrio species were prevalent in the intestinal samples of crabs fed with wild fishes.

Outbreak of vibriosis associated with Vibrio parahaemolyticus in the mud crab Scylla paramamosain cultured in China.

In this study, a Gram-negative bacterium was isolated from diseased Scylla paramamosain and tentatively named strain QX17. The bacterial isolate was identified as Vibrio parahaemolyticus based on morphological and biochemical characteristics and molecular identification with the 16S rRNA and HSP60 genes. In the challenge experiment, S. paramamosain injected intramuscularly with the V. parahaemolyticus isolate developed pathological signs similar to the naturally diseased mud crabs. The infection experiment also showed that the median lethal dosage (LD50) for QX17 was 4.79 × 102 CFU g-1 (crab weight). Histopathological analysis of the diseased mud crabs infected with V. parahaemolyticus showed deformation and basement membrane rupture of hepatopancreatic tubules in the hepatopancreas, and disordered and broken muscle fiber in the muscle. Antimicrobial susceptibility tests revealed that QX17 was highly sensitive to most of the tested aminoglycosides, tetracyclines, and quinolones. To the best of our knowledge, this is the first study reporting isolation and antibiotic sensitivities of V. parahaemolyticus from cultured mud crabs. The discovery of V. parahaemolyticus in cultured mud crabs not only adds to the growing list of emerging pathogens in crab aquaculture in China, but also highlights the necessity of developing early detection strategies and appropriate interventions to reduce the damage caused by V. parahaemolyticus in mud crab aquaculture.

Effects of different salinity on the transcriptome and antibiotic resistance of two Vibrio parahaemolyticus strains isolated from Penaeus vannamei cultured in seawater and freshwater ponds.

The transcriptome and antibiotic resistance of Vibrio parahaemolyticus isolated from Penaeus vannamei cultured in seawater (strain HN1)and freshwater (strain SH1) ponds were studied at different salinity (2‰ and 20‰). At different salinity, 623 differentially expressed genes (DEGs) significantly upregulated and 1,559 DEGs significantly downregulated in SH1. In HN1, 466 DEGs significantly upregulated and 1,930 DEGs significantly downregulated, indicating high salinity can lead to the downregulation of most genes. In KEGG analysis, the expression of DEGs annotated to starch and sucrose metabolism pathway was higher at 2‰ salinity than at 20‰ salinity in HN1 and SH1, implying salinity affected bacterial growth mainly through this pathway. In the enrichment analysis of upregulated DEGs, two pathways (Valine, leucine, and isoleucine degradation, and Butanoate metabolism) were significantly enriched at different salinity. Antibiotic-susceptibility test discovered that SH1 isolated from P. vannamei cultured in freshwater was resistant to multiple drugs, including kanamycin, gentamicin, medemycin, and azithromycin, at a salinity of 2‰, whereas at 20‰ salinity, SH1 was not resistant to the drugs. The HN1 strain isolated from P. vannamei cultured in mariculture was resistant to polymyxin B and clindamycin at 20‰ salinity. Whereas, HN1 was intermediately susceptible to these two antibiotics at 2‰ salinity. These results indicate that the drug resistance of bacteria was affected by salinity. Furthermore, beta-lactam resistance was significantly enriched in SH1 at different salinity, and the inhibition zone of penicillin G was consistent with the results of a beta-lactam resistance pathway.