Immunomodulating potency of lipopolysaccharides (LPS) derived from smooth type of bacterial pathogens in Indian major carp

Lipopolysaccharides (LPS), the outer membrane of the Gram-negative bacteria, are reported to stimulate the immunity of different vertebrates including fish. However, their potency and spectrum of actions often differ among different bacteria. In this study, effect of crude LPS, derived from three species of smooth Gram-negative bacterial fish pathogens viz. Edwardsiella tarda, Escherichia coli, and Pseudomonas fluorescens, on certain innate immune parameters of Indian major carp, Labeo rohita was studied. L. rohita yearlings, when injected intraperitoneally with crude LPS extracted from these bacteria showed little variations in different innate immune parameters. Furthermore, LPS injected fish were protected against a virulent E. tarda challenge. Although, no significant difference (p>0.05) in most of the immune parameters were found with LPS of different bacteria, the E. coli LPS injected fish elucidated high resistivity during challenge study. Hence, there could be some variations in LPS with respect to the bacterial type which needs to be further explored.     

Thermal degradation of anthocyanins from purple potato (cv. Purple Majesty) and impact on antioxidant capacity

Degradation parameters of purified anthocyanins from purple-fleshed potato (cv. Purple Majesty) heated at high temperatures (100-150 °C) were determined. Purified anthocyanins, prepared by removing salts, sugars, and colorless nonanthocyanin phenolics from the crude extract, were monitored and quantified using HPLC and spectrophotometry for heat-induced degradation products. Separation of colorless phenolics from the anthocyanins was confirmed using HPLC at two wavelengths, 280 and 520 nm. The degradation kinetics of purified anthocyanins followed a first-order reaction with reaction rate constants (k values) of 0.0262-0.2855 min(-1), an activation energy of 72.89 kJ/mol, thermal death times (D values) of 8.06-8789 min, and a z value of 47.84 °C over the temperature range of 100-150 °C. The enthalpy and entropy of activation were 59.97 kJ/mol and -116.46 J/mol·K, respectively. The antioxidant capacity in the purified anthocyanins, measured by DPPH and ABTS assays, was increased after the thermal treatment, indicating antioxidant activities of degradation products in the samples.     

Algal Phlorotannins as Novel Antibacterial Agents with Reference to the Antioxidant Modulation: Current Advances and Future Directions

The increasing drug resistance of infectious microorganisms is considered a primary concern of global health care. The screening and identification of natural compounds with antibacterial properties have gained immense popularity in recent times. It has previously been shown that several bioactive compounds derived from marine algae exhibit antibacterial activity. Similarly, polyphenolic compounds are generally known to possess promising antibacterial capacity, among other capacities. Phlorotannins (PTs), an important group of algae-derived polyphenolic compounds, have been considered potent antibacterial agents both as single drug entities and in combination with commercially available antibacterial drugs. In this context, this article reviews the antibacterial properties of polyphenols in brown algae, with particular reference to PTs. Cell death through various molecular modes of action and the specific inhibition of biofilm formation by PTs were the key discussion of this review. The synergy between drugs was also discussed in light of the potential use of PTs as adjuvants in the pharmacological antibacterial treatment.     

The action of phosphine against the eggs of phosphine-resistant and -susceptible strains of Rhyzopertha dominica F

The effect of phosphine at exposure periods of 24, 48 and 120 h on hatching and mortality of 0- to 1-day-old eggs of susceptible (TN6) and resistant (FC10) strains of Rhyzopertha dominica of field origin was investigated. The fumigant affected hatching in both the strains. In a 48-h exposure at 27 (+/- 2) degrees C, the LD99 doses for the eggs of TN6 and FC10 were 0.56 and 3.25 mg litre-1, respectively. Significant reduction in hatching was observed in treated batches with progressive increase of phosphine dose in the first 2-3 days. On subsequent days the numbers hatching were often similar to those in controls, and sometimes exceeded control hatch, especially following a 5-day exposure. A critical change in the order of susceptibility of egg and adult stages of the two strains was noticed. In 48-h exposures, eggs of the susceptible strain were more tolerant than their adults, whilst the reverse was true in the resistant strain.     

Gaseous carbon emission in relation to soil carbon fractions and microbial diversities as affected by organic amendments in tropical rice soil

The interactive effects of moisture and organic amendments (farmyard manure (FYM), crop residue (CR) and green manure (GM) (Sesbania aculeata) on gaseous carbon (C) emission, soil labile C fractions, enzymatic activities and microbial diversity in tropical, flooded rice soil were investigated. The amendments were applied on equal C basis in two moisture regimes, that is, aerobic and submergence conditions. The CO₂ production was significantly higher by 22% in aerobic than in submergence condition; on the contrary, the CH₄ production was 27% higher under submergence condition. The labile C fractions were significantly higher in GM by 26% under aerobic and 30% under submergence conditions, respectively, than control (without any kind of fertilizer or amendments). Eubacterial diversity identified by PCR-DGGE method (polymerase chain reaction coupled with denaturant gradient gel electrophoresis) was higher under GM followed by FYM, CR, and control and it is pronounced in submerged condition. GM favored the labile C accumulation and biological activities under both submergence and aerobic conditions, which makes it most active for soil–plant interactions compared to other organic amendments. Considering environmental sustainability, the use of GM is the better adoptable option, which could enhance labile C pools, microbial diversities in soil and keep soil biologically more active.     

Development and validation of the Canine Atopic Dermatitis Lesion Index,a scale for the rapid scoring of lesion severity in canine atopic dermatitis

Background – The third iteration of the Canine Atopic Dermatitis Extent and Severity Index (CADESI‐03) is the only tool rigorously validated for canine atopic dermatitis (CAD) lesion scoring. The CADESI‐03 requires 248 evaluations, limiting its widespread use. Hypothesis/Objectives – The goal of the study was to develop and validate a practical method of grading CAD lesions that requires scoring only the frequently affected body regions. Animals – Fifty‐seven privately owned atopic dogs were used in the study. Methods – The Canine Atopic Dermatitis Lesion Index (CADLI) was evaluated in an open, multicentre reliability study. Validity was assessed with expert opinion (content validity) and comparison of CADLI with existing disease severity measures (construct and criterion validity). Reliability was evaluated by analysing repeated observations of each dog. Convenience was assessed in terms of the time required to complete the scale. Results – The CADLI scores correlated with overall assessment scores (r = 0.60, P < 0.001, linear mixed model) and pruritus severity scores (r = 0.53, P < 0.001, linear mixed model), establishing construct validity. The CADLI was strongly correlated with CADESI‐03 (r = 0.84, P < 0.001, linear mixed model), establishing criterion validity. The CADLI values obtained by two observers correlated very strongly (r = 0.91, P < 0.001), as did the repeat values for the same observer (r = 0.98, P < 0.001). The mean time to complete the CADLI was less than that required for CADESI‐03 (1.9 and 12.6 min, respectively), a highly significant difference (P < 0.001). Conclusion and clinical importance – The CADLI was found to be an effective measure of CAD lesion severity, strongly correlating with CADESI‐03. The convenience of CADLI makes it suitable for use in both clinical research and practice.     

High antigenic cross-reaction among the bacterial species responsible for diseases of cultured freshwater fishes and strategies to overcome it for specific serodiagnosis

Antigenic sharing among the most commonly bacterial pathogens such as Aeromonas hydrophila, Edwardsiella tarda and Pseudomonas fluorescens of Indian major carps has been studied using immunological reactions such as cross-agglutination, disc diffusion and indirect enzyme linked immunosorbent assay (ELISA). The data were analysed using statistical analysis (SAS), version 6.12. The results showed high antigenic similarities among the bacterial whole cells, whole cell lysates, somatic 'O' antigens, lipopolysaccharides (LPS) and extracellular products (ECP). However, few or no similarities were observed in ECP components of <20kD. The present study indicates a need to develop differential diagnostic methods based on serology by choosing the highly specific less cross-reactive ECP antigen.     

Inhibition of egg development by phosphine in the cosmopolitan pest of stored products Liposcelis bostrychophila (Psocoptera: Liposcelididae)

Phosphine-induced delay in development of eggs was investigated as a mechanism of resistance to this fumigant in Liposcelis bostrychophila Badonnel. One-day-old eggs of a susceptible and a strongly resistant strain of L bostrychophila were exposed to a range of phosphine concentrations for 6days at 30 (+/- 1) degrees C and 70 (+/- 2)% RH. Delay in mean hatching period occurred in both susceptible and resistant eggs, although it was more pronounced in the latter. A maximum delay of 2.65 days was recorded for eggs of the susceptible strain at 0.01 mg litre(-1) (the highest concentration at which eggs survived) and 13.39 days for the resistant strain at 1 mg litre(-1) (the highest concentration tested). Delay in egg development time was positively correlated with increasing phosphine concentration. Our results reveal that the most successful strategy to control resistant L bostrychophila is to apply relatively low concentrations of phosphine for extended exposure times (eg 0.05 mg litre(-1) for 16 days) that allow all eggs to hatch to the much less tolerant nymph stage.     

Complete genome sequencing and assessment of mutation-associated protein dynamics of the first Indian bovine ephemeral fever virus (BEFV) isolate

BackgroundBovine ephemeral fever (BEF) is a re-emerging disease caused by bovine ephemeral fever virus (BEFV). Although it poses a huge economic threat to the livestock sector, complete viral genome information from any South Asian country, including India, lacks.AimGenome characterization of the first Indian BEFV isolate and to evaluate its genetic diversity by characterizing genomic mutations and their associated protein dynamics.Materials and MethodsOf the nineteen positive blood samples collected from BEF symptomatic animals during the 2018-19 outbreaks in India, one random sample was used to amplify the entire viral genome by RT-PCR. Utilizing Sanger sequencing and NGS technology, a complete genome was determined. Genome characterization, genetic diversity and phylogenetic analyses were explored by comparing the results with available global isolates. Additionally, unique genomic mutations within the Indian isolate were investigated, followed by in-silico assessment of non-synonymous (NS) mutations impacts on corresponding proteins’ secondary structure, solvent accessibility and dynamics.ResultsThe complete genome of Indian BEFV has 14,903 nucleotides with 33% GC with considerable genetic diversity. Its sequence comparison and phylogenetic analysis revealed a close relatedness to the Middle Eastern lineage. Genome-wide scanning elucidated 30 unique mutations, including 10 NS mutations in the P, L and G_NS proteins. The mutational impact evaluation confirmed alterations in protein structure and dynamics, with minimal effect on solvent accessibility. Additionally, alteration in the interatomic interactions was compared against the wild type.ConclusionThese findings extend our understanding of the BEFV epidemiological and pathogenic potential, aiding in developing better therapeutic and preventive interventions.