Purification, structural characterization, and neuroprotective effect of 3,6-diisobutyl-2,5-piperazinedione from Halomonas pacifica CARE-V15 against okadaic acid-induced neurotoxicity in zebrafish model.

Halomonas pacifica CARE-V15 was isolated from the southeastern coast of India to determine its genome sequence. Secondary metabolite gene clusters were identified using an anti-SMASH server. The concentrated crude ethyl acetate extract was evaluated by GC-MS. The bioactive compound from the crude ethyl acetate extract was fractionated by gel column chromatography. HPLC was used to purify the 3,6-diisobutyl-2,5-piperazinedione (DIP), and the structure was determined using FTIR and NMR spectroscopy. Purified DIP was used in an in silico molecular docking analysis. Purified DIP exhibits a stronger affinity for antioxidant genes like glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GSR). Using in silco molecular docking analysis, the protein-ligand binding affinities of GSR (-4.70 kcal/mol), GST (-5.27 kcal/mol), and GPx (-5.37 kcal/mol) were measured. The expression of antioxidant genes were investigated by qRT-PCR. The in vivo reactive oxygen species production, lipid peroxidation, and cell death levels were significantly (p ≤ 0.05) increased in OA-induced group, but all these levels were significantly (p ≤ 0.05) decreased in the purified DIP pretreated group. Purified DIP from halophilic bacteria could thus be a useful treatment for neurological disorders associated with oxidative stress.

Antioxidant and Teratogenic Activities of Formulated Agar Extracted from Brown Seaweed Turbinaria conoides against Zebrafish Larvae.

This study examines the antioxidant and teratogenic effects of two different type's methods of formulating agar from Turbinaria conoides (T. conoides) using a zebrafish model. The agar was extracted using the aqueous extraction method and developed in two different formulations using separate procedures. Formulated agar1 (FA1) used a higher concentration of the ingredients while formulated agar 2 (FA2) had a lesser concentration. The two unique formulated agars (FAs) were studied using biochemical composition, Fourier infrared (FT-IR) spectroscopy, gas chromatography-mass spectroscopy (GC-MS), and scanning electron microscopy (SEM). The antioxidant activities of both FAs in vitro were shown to be significantly different (P < 0.05) at various concentrations (60-180 µl/ml) in the study. The toxicity of the FAs was dose-dependent, with FA1 having the least teratogenic activity when compared to FA2. In comparison to FA2, FA1 was found to have higher antioxidant activity. At various concentrations (0.5, 0.25, and 0.125 µg/ml), the teratogenic activity of two FAs was examined in zebrafish embryos (ZFE) at 24, 48, 72, and 96 hours post fertilization (hpf). Both FAs exhibit dose-dependent toxicity and increased antioxidant activity, and this can be utilized as an alternative for standard antioxidants, according to this study.

Antioxidant and Antiaging Properties of Agar Obtained from Brown Seaweed Laminaria digitata (Hudson) in D-Galactose-Induced Swiss Albino Mice.

The present paper explores the antioxidant and antiaging properties of agar extracted from Laminaria digitata (L. digitata) on a D-galactose (D-Gal)-induced mouse model. Experimental mice were divided into four groups: group I comprised of control nontreated mice, group II comprised of D-Gal-induced mice, group III mice were treated with extracted agar after D-Gal induction, and group IV mice were given ascorbic acid as a positive control. Antioxidant enzymes and aging marker proteins declined significantly in group II, whereas they were normal in group III and group IV mice. Expressions of interleukin-1ß (IL-1ß) in D-Gal-induced mice were significantly enhanced in the liver and brain of the experimental mice, which were otherwise normal in agar-treated mice. Also, IL-6 levels were significantly increased in the liver and reversed in the brain of D-gal mice, while it was regularly in the agar-treated mice. The histopathological analysis of D-Gal-induced mice showed spongiosis and tangles in brain cells, increased fat and decreased collagen contents in the skin, and few dilated sinuses in the hepatic cells. The changes were under control in group III and group IV mice, suggesting the protective effects of agar extracted from L. digitata and ascorbic acid.

Low molecular weight sulfated chitosan isolation, characterization and anti-tuberculosis activity derived from Sepioteuthis lessoniana.

The research focused on tuberculosis as it is one of the world's most serious health problems. The extracted chitin from the gladius of Sepioteuthis lessoniana converted into Chitosan (CH). The purified and freeze-dried CH was refined as Sulfated Chitosan (SCH). The SCH was converted into low molecular weight of SCH with various doses of Gamma Irradiation (GIR). Fluorescence characteristics of GIR-SCH and elemental analysis were confirmed. The structure and molecular weights of GIR-SCH were determined with FT-IR, NMR and MALDI-TOF/Mass Spectroscopy. 100 Gy of GIR-SCH significantly showed the minimum inhibitory concentration (MIC) against Mycobacterium smegmatis. The MIC against M. smegmatis was not affected by the varied sulfate levels in the identical molecular weight GIR-SCH. However, the lowest molecular weight GIR-SCH displayed a significantly MIC against M. smegmatis. In docking analysis, the 6ZT3 ligand had the lowest binding energy of -1.57 kcal/Mol indicating a superior binding interaction with GIR-SCH. The effect of molecular weight reduction by GIR on the anti-tuberculosis capacity of GIR SCH was investigated in this study which had antimicrobial implications.

An emerging threat of ceftriaxone-resistant non-typhoidal salmonella in South India: Incidence and molecular profile.

Background: Non-typhoidal Salmonella (NTS) infection is a serious public health problem globally. Although NTS infections are self-limited, antimicrobial therapy is recommended for severe infections and immunocompromised patients. Antimicrobial resistance (AMR) in these pathogens further limits its therapeutic options. Here, we report an incidence of ceftriaxone resistance in NTS over the past 9 years in a southern Indian region. Materials and Methods: Molecular mechanisms of resistance in ceftriaxone-resistant NTS have been tested by both phenotypic and molecular methods. Minimum inhibitory concentration was determined by the E-test and broth microdilution method. AMR gene markers of ß-lactamases such as AmpCs (blaMOX, blaCMY, blaDHA, blaFOX, blaACC and blaACT) and extended-spectrum ß-lactamases (ESBLs) (blaSHV, blaTEM, blaVEB, blaPER, blaCTXM-1like,blaCTXM-2like, blaCTXM-8like, blaCTXM-9like and blaCTXM-25like) were screened. The presence of IncH12 and IncI1 plasmid was also analysed. Results: The study reports a 5% prevalence of ceftriaxone resistance in NTS. The most common serogroup was Salmonella Group B followed by Salmonella Group E and Salmonella group C1/C2. The occurrence of blaCTX-M-1, blaTEM, blaCMY and blaSHV genes was observed in 54%, 54%, 48% and 3% of the isolates, respectively. Interestingly, few isolates carried dual resistance genes (ESBLs and AmpCs). IncH12 and IncI1 plasmid was identified in isolates carrying ESBL and AmpC genes, respectively. Conclusion: This study shows that ceftriaxone resistance is mainly mediated by ß-lactamases such as ESBL and AmpC. As the incidence of ceftriaxone resistance is rising gradually over the years, it is imperative to monitor the AMR in this species.

Extensive drug resistant Salmonella enterica serovar Senftenberg carrying blaNDM encoding plasmid p5558 (IncA/C) from India.

Non-typhoidal Salmonella (NTS) are foodborne pathogens that are responsible for self-limiting gastroenteritis in humans. The present study aims at the molecular characterisation and comparative genomics of Salmonella enterica serovar Senftenberg strain P5558 isolated from the pus samples of a patient suffering from stump infection. The isolate was subjected to serotyping and antimicrobial susceptibility test to understand the phenotypical characteristics. Whole genome sequencing (WGS) was carried out and comparative genomics using computational tools showed the antimicrobial resistance and virulence gene profile of the isolates from the genome sequence data. Typing experiments confirmed that the isolate belong to S. Senftenberg with sequence type ST14. Resistance against ß-lactams is associated with the presence of blaTEM-1, blaOXA-9, blaCMY-2 and blaNDM-1 genes. Similarly resistance to aminoglycoside was associated with five aminoglycoside modifying enzymes aac(6')-Ia, aac(6')-Ib, aph(3')-Ib, aph(6')-Ib and ant(3'')-Ia, sulfonamide with sul-1 and sul-2 and chloramphenicol with florR gene. Substitutions in gyrA (S83Y, D87G) and parC (S80I) genes found to be the reason for fluoroquinolone resistance. The plasmid profiling showed the isolate has four resistance plasmids in which plasmid p5558-NDM (IncA/C) harbours major resistance genes including blaNDM-1 and blaCMY-2. Determination of virulence gene profile revealed that the genome carries all major Salmonella pathogenicity islands and virulence factors. From our findings it is clear that the isolate possess characteristic pathogenicity islands (SPI 1-6, 13, 14), major virulence factors and acquired resistance genes. Comparative analysis suggests the evolution and distribution of the MDR gene encoding plasmids in NTS.