Emergence of multidrug resistant, ctx negative seventh pandemic Vibrio cholerae O1 El Tor sequence type (ST) 69 in coastal water of Kerala, India.

Seventh pandemic Vibrio choleare O1 El Tor strain is responsible for the on-going pandemic outbreak of cholera globally. This strain evolved from non-pathogenic V. cholerae by acquiring seventh pandemic gene (VC 2346), pandemic Islands (VSP1 and VSP2), pathogenicity islands (VP1 and VP2) and CTX prophage region. The cholera toxin production is mainly attributed to the presence of ctx gene in these strains. However, several variants of this strain emerged as hybrid strains or atypical strains. The present study aimed to assess the aquatic environment of Cochin, India, over a period of 5 years for the emergence of multidrug resistant V. cholerae and its similarity with seventh pandemic strain. The continuous surveillance and monitoring resulted in the isolation of ctx negative, O1 positive V. cholerae isolate (VC6) from coastal water, Cochin, Kerala. The isolate possessed the biotype specific O1 El Tor tcpA gene and lacked other biotype specific ctx, zot, ace and rst genes. Whole genome analysis revealed the isolate belongs to pandemic sequence type (ST) 69 with the possession of pandemic VC2346 gene, pathogenic island VPI1, VPI2, and pandemic island VSP1 and VSP2. The isolate possessed several insertion sequences and the SXT/R391 family related Integrative Conjugative Elements (ICEs). In addition to this, the isolate genome carried virulence genes such as VgrG, mshA, ompT, toxR, ompU, rtxA, als, VasX, makA, and hlyA and antimicrobial resistance genes such as gyrA, dfrA1, strB, parE, sul2, parC, strA, VC1786ICE9-floR, and catB9. Moreover, the phylogenetic analysis suggests that the isolate genome is more closely related to seventh pandemic V. cholerae O1 N16961 strain. This study reports the first incidence of environmental ctx negative seventh pandemic V. choleare O1 El Tor isolate, globally and its presence in the aquatic system likely to induce toxicity in terms of public health point of view. The presence of this isolate in the aquatic environment warns the strict implementation of the epidemiological surveillance on the occurrence of emerging strains and the execution of flagship program for the judicious use of antibiotics in the aquatic ecosystem.

Scope and challenges of seaweed utilization in food and nutraceutical industry in India: a review.

Seaweeds are an excellent source of unique antioxidant phytochemicals, dietary fibres, essential amino acids, vitamins, polyunsaturated fatty acids and minerals. The presence of such structurally diverse and high value bioactive compounds has led to popularization of seaweed as functional food ingredient in global health supplement market. India, with a long coastline of 8100 km and exclusive economic zone of 2.17 million km2, is rich in diverse seaweed resources belonging to almost 700 species. However, food and nutraceutical application of Indian seaweed is highly constrained. Apart from Kappaphycus alvarezii, there is no systematic commercial cultivation of seaweed in India. The regulatory framework for use of seaweed as food is still developing and consumer acceptance is still low. However, there is a timely and renewed interest from different government agencies and research organisations to develop a thriving food and nutraceutical industry using India's vast seaweed resources. The review briefly describes the nutritional and functional food potential of the seaweed and goes on to discuss the scope of seaweed utilization in food and nutraceutical industry in India. Further, the review has identified the regulatory challenges and quality control requirements for use of seaweeds in food and nutraceuticals.

Intrinsic properties of chitosan on the characteristics of gold nanoparticles and its application as smart packaging device.

Storage temperature fluctuation is a major problem faced in food and pharmaceutical industry, apart from prevailing fraud in marketing frozen products as fresh. The present work aimed to study the effect of intrinsic properties of chitosan on synthesis and performance of gold nanoparticles as smart packaging devices. Different types of Chitosan from shrimp waste were used as reducing and capping agent in the synthesis of metal nanoparticle. Time is taken to reduce gold atom to gold nanoparticles varied with the type of reducing agent, between 6 min 40 s to 15 min 02 s. The maximum absorbance (λmax) for AuNPs was observed between 517 and 530 nm. An increase in the concentration of chitosan resulted in smaller and uniform size AuNPs with size ranging from 8.09 to 9.95 nm compared with 14.44 to 19.88 nm for lower concentration of chitosan. Visible ruby red colour of AuNPs synthesised using trisodium citrate (TSC) and lower concentration of chitosan (0.1%) changed to colourless and grey to blue, respectively upon exposure to frozen condition (-18 °C ± 1 °C). UV Visible spectra indicated distinctly different (broader) spectrum with reduced peak intensity. A visible change in colour from ruby red to bluish and colourless state indicates that irrespective of the properties of available chitosan, it can be used for synthesis of gold nanoparticles as smart packaging to distinguish packed fresh/chilled/refrigerated products from frozen ones.

Modifying textural and functional characteristics of fish (Nemipterus japonicus) mince using high pressure technology.

Effect of high pressure in inducing textural and functional modification has been investigated in pink perch (Nemipterus japonicus) mince. Fish mince undergone pressurization at 200, 400 and 600 MPa for a holding period of 10 min and was compared against cooked mince (90 °C; 40 min). The treated mince at 400 and 600 MPa lost its natural viscosity and behaved like cooked mince through denaturation and formation of protein aggregates. Textural characterisation showed the retention of tenderness in 200 MPa treated samples, but become harder on application of higher pressures. Unlike heat gels, pressure induced gels were more smooth, white and elastic in nature. A decreased in reactive SH groups was observed in 400 and 600 MPa treated samples due to the formation of disulfide bonds. Hydrophobic concentration was higher in cooked and 600 MPa treatments whereas Ca2+-ATPase activity decreased after pressurization. On application of different pressures microbial reduction of 2-3 log cycles was achieved in the mince samples. Hence pressure treatments at lower ranges cannot alter the texture and functionality of protein and the mince can undergo processing as required. Besides extending shelf life, the treatments above 400 MPa can make irreversible effect on texture quality and protein functionality which is similar to that of cooking.

Influence of corn starch based bio-active edible coating containing fumaric acid on the lipid quality and microbial shelf life of silver pomfret fish steaks stored at 4 °C.

The present study aimed at assessing the impact of addition of fumaric acid (0.5%), as an active agent, in a corn starch (2%) based edible coating, on the lipid quality and microbial shelf life of silver pomfret (Pampus argenteus) fish steaks stored at 4 °C. Treating fish steaks with FA resulted in a bacteriostatic effect leading to reduced counts of total mesophilic and psychrotrophic bacteria, H2S producing bacteria and Pseudomonas spp. The total mesophilic bacterial count of uncoated control sample exceeded the permissible limit of 7 log cfu g-1 on 6th day and had the lowest microbial shelf life. FA incorporation in the CS coating improved the microbial stability of fish steaks resulting in a shelf life of 15 days. The outcomes of the study suggest that CS based coating is beneficial in delaying lipid oxidation as displayed by the lower TBA and PV values while FA is an effective agent for further increasing the preservative action of CS coating by significantly inhibiting microbial growth as well as lipid quality deterioration, which could be exploited by the seafood industry as an active packaging component.

Phlorotannins-bioactivity and extraction perspectives.

Phlorotannins, a seaweed based class of polyphenolic compounds, have proven to possess potential bioactivities such as antioxidant, antimicrobial, anti-allergic, anti-diabetic, anti-inflammatory, anti-cancerous, neuroprotection etc. These bioactivities have further increased demand globally and sustainable techniques such as supercritical fluid extraction, microwave assisted extraction, enzyme assisted extraction, extraction using deep eutectic solvents etc. are being explored currently for production of phlorotannin-rich extracts. In spite of such well documented bioactivities, very few phlorotannin-based nutraceuticals are available commercially which highlights the significance of generating consumer awareness about their physiological benefits. However, for industry level commercialization accurate quantification of phlorotannins with respect to the different classes is vital requiring sophisticated analytical techniques such as mass spectrometry, 1H-NMR spectroscopy etc. owing to the wide structural diversity. This review summarizes the extraction and bioactivities of phlorotannins based on the findings of in vivo and in vitro studies.

Exploring the physical and quality attributes of muffins incorporated with microencapsulated squalene as a functional food additive.

Squalene, a triterpenoid compound is proven to possess immense bioactivities by virtue of its high antioxidant activity. The present study was designed to investigate the quality attributes of muffins as influenced by addition of encapsulated squalene. Nutritional analysis showed that calorific value of prepared muffins has ranged from 480.78 ± 0.10 to 501.61 ± 0.38 kcal. Baking loss was lowest in case of muffins prepared with encapsulated squalene with its crumb region recorded higher moisture content. Color kinetics study indicated that browning index (BI) was higher in crust portion of encapsulated squalene enriched muffins. Scanning electron micrographs showing that muffins with encapsulated squalene had stronger structural organization. This was further supported by the textural studies showed that the muffins with encapsulated squalene was cohesive, springier and chewy with less gumminess and stiffness indicating their efficacy in improving the textural quality. Oxidative stability and microbiological quality were also high in squalene enriched foods suggesting that squalene might have some antimicrobial effects. Outcome of the study indicated that encapsulated squalene can be very well utilised as a functional food ingredient in ready -to-eat functional foods. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at (10.1007/s13197-020-04955-9).

Pufferfish poisoning from Arothron stellatus: The first confirmed case in India with exact DNA sequencing-based species identification.

A puffer fish poisoning case was reported from the coastal city of Veraval in the Gujarat state of India with patient reporting symptoms of giddiness, vertigo, aphasia and heaviness of head following consumption of cooked fish. Treatment was purely symptomatic and supportive. The patient was discharged from the hospital in a stable condition after 4 days. The suspected fish species was later identified using DNA (Deoxyribonucleic Acid) sequencing as Arothron stellatus with 100% identity.

Effect of added calcium and heat setting on gel forming and functional properties of Sardinella fimbriata surimi.

Present study evaluates the effect of calcium and heat setting on gel characteristics of lesser sardine (Sardinella fimbriata) surimi. Total seven formulations were made namely, S. fimbriata minced meat without heat setting (A1), minced meat with heat setting (A2), S. fimbriata surimi control (without addition of calcium) without heat setting (B1), control (without addition of calcium) with heat setting (B2), surimi added with 0.3% calcium without heat setting (C1) and surimi added with calcium with heat setting (C2) and refiner meat without addition of calcium and with addition of sodium bicarbonate (D). C1 exhibited gel strength of 329 g cm (Grade KA) whereas C2 sample exhibited gel strength of 556.2 g cm (Grade AA) as a result of gel setting at 35 °C for 45 min. Textural parameters such as hardness, chewiness, gumminess and cohesiveness were improved in C2 when compared with all other formulations. Addition of calcium and sodium bicarbonate significantly improved whiteness of surimi with gel setting in comparison to other treatments (p < 0.05). C2 samples exhibited reduced thio barbituric acid (TBA) values indicating lower oxidation. Results indicated potential for use of fish species with high fat content and darker meat for surimi manufacture with gel setting of sol and addition of sodium bicarbonate and calcium as ingredients.

Optimizing air-frying process conditions for the development of healthy fish snack using response surface methodology under correlated observations.

Air frying technique was used for the preparation of fish cutlet-a popular fish snack with low fat content, better protein content and color. The process conditions viz: temperature varying from 160 to 200 °C and time varying from 5 to 15 min were optimized using response surface methodology. A factorial design with 9 runs satisfying rotatability conditions under correlated errors was formulated for the experiment. The parameters of first order response surface model with interaction were estimated by generalized least square method. The optimum temperature-time combination for air-frying condition was found to be 180 °C and 12 min, respectively for low fat content, better protein content and colour, comparable texture profile and sensory acceptability when compared to deep fried fish cutlet samples. Air-fried fish cutlets can be a healthier protein rich snack product as an alternative to deep fat fried fish cutlets.

Chitosan-capped gold nanoparticles for indicating temperature abuse in frozen stored products.

The present study aimed to optimize the conditions for the synthesis of gold nanoparticles (AuNP) using chitosan and to assess its effectiveness as temperature threshold indication for frozen storage conditions. Chitosan concentration of 0.25% and temperature of 90 °C for 15 min was optimum for synthesizing AuNP. The maximum absorbance (λ max) was observed at 530 and 540 nm for 0.125% and 0.25% chitosan, respectively, indicating shifting of peak toward longer wavelengths (red shift) with increasing chitosan concentration indicating larger AuNPs. A prominent absorption peak at 1367 cm-1 by Fourier transform-infrared (FTIR) spectrum corresponding to C-C stretching of the glucosamine group of chitosan indicates the chitosan capping on the AuNP. Higher peak intensity and a peak shift toward shorter wavelength were observed for AuNPs exposed to frozen temperature abused conditions. Distinctly clear visible color variation from cherry red to gray indicates its application as temperature abuse indicator in frozen products.

Evaluation of physicochemical characteristics of microwave vacuum dried mackerel and inhibition of oxidation by essential oils.

In the present study, Indian mackerel was dried by microwave vacuum drying (MVD) method and compared its physico chemical quality to mackerel dried by hot air drying (HAD) method. Antioxidant effects of thyme oil (TMO) and clove leaf oils (CLO) during storage were also evaluated. Brine salted mackerel was dried in hot air oven (50-55 °C) and microwave vacuum dryer (600 W and 600 Hg mm). For essential oil treatment, mackerel was dipped in 0.75% TMO and CLO for 5 min. Moisture content of MVD and HAD samples was reduced to 30-32% in 1.2 h and 12 h, respectively. Rehydration ability and water absorption index of MVD samples were significantly higher to that of HAD samples. Mackerel dried by HAD showed significantly higher salt soluble and water soluble protein nitrogen fractions than that of MVD samples. Significantly higher hardness and chewiness values were observed for HAD samples. Color and appearance of uncooked MVD sample was superior to that of HAD samples. As per the results of PV and TBARS, TMO exhibited better antioxidant effect compared to CLO. The study demonstrated that fast drying can be achieved by microwave vacuum dryer and it can produce dried fish having better sensory and textural attributes.

Sardine oil loaded vanillic acid grafted chitosan microparticles, a new functional food ingredient: attenuates myocardial oxidative stress and apoptosis in cardiomyoblast cell lines (H9c2).

Fish oil has been widely recognized as an excellent dietary source of polyunsaturated n-3 fatty acids such as EPA and DHA. However, it can undergo oxidation easily resulting in the formation of toxic off flavor compounds such as hydroperoxides. These compounds adversely affect the nutritional quality and may induce several stress reactions in body. To solve this problem, a new antioxidant bio-material, vanillic acid-grafted chitosan (Va-g-Ch), was synthesized and used as a wall material for microencapsulation of fish oil. The sardine oil loaded Va-g-Ch microparticles could be a potential functional food ingredient considering the numerous health benefits of fish oil, chitosan, and vanillic acid. The current study aimed to investigate the possible protective effect of sardine oil-loaded Va-g-Ch microparticles against doxorubicin-induced cardiotoxicity and the underlying mechanisms. In vitro cytotoxicity evaluation was conducted using H9c2 cardiomyocytes. MTT assay revealed that effective cytoprotective effect was induced by a sample concentration of 12.5 µg/mL. Results of apoptosis by double fluorescent staining with acridine orange/ethidium bromide and caspase-3 evaluation by ELISA substantiated the above findings. Further, flow cytometric determination of membrane potential, relative expression of NF-κB by PCR, and ROS determination using DCFH-DA also confirmed the protective effect of encapsulated sardine oil against doxorubicin-induced cardiotoxicity. NF-κB expression was down-regulated nearly by 50% on cells treated with encapsulated sardine oil. Altogether, the results revealed that sardine oil-loaded Va-g-Ch microparticles demonstrated potential cell protection against doxorubicin-induced oxidative stress.

Draft Genome Sequence of a Methicillin-Resistant Sequence Type 39 Staphylococcal Isolate Obtained from Seafood.

The draft genome sequence of a methicillin-resistant Staphylococcus aureus (MRSA) sequence type 39 (ST 39) isolate obtained from the dried ribbonfish of Gujarat, India, is reported here. Staphylococcus-specific genes were present in this MRSA isolate. The whole-genome sequence of this strain contains 2,693 protein-coding genes and 70 RNAs within the 2.82-Mb genome.

Draft Genome Sequence of a Methicillin-Resistant Staphylococcus aureus Isolate (Sequence Type 1) from Seafood.

The draft genome sequence of a methicillin-resistant Staphylococcus aureus (MRSA) isolate (sequence type 1 [ST 1]) from the salted dried ribbonfish from Gujarat, India, is reported here. Staphylococcus genus-specific genes were present in this MRSA isolate. The whole-genome sequence of this strain contains 2,797 protein-coding genes and 80 RNAs within the 2.85-Mb genome.

Microencapsulation of sardine oil: Application of vanillic acid grafted chitosan as a bio-functional wall material.

Vanillic acid grafted chitosan (Va-g-Ch) was evaluated as a new antioxidant wall material for microencapsulation of polyunsaturated fatty acid rich sardine oil. A high grafting ratio of 305mg vanillic acid equivalent/g of polymer was achieved using a free radical mediated grafting reaction. Oil in water emulsion was prepared with an optimised combination of Va-g-Ch and Tween 20 (3.2:1). Sardine oil loaded microparticles (SO-M) were produced (∼75% yield) by spray drying. The average diameter and polydispersity Index (PDI) of the particles were found to be 2.3µ and 0.345. XRD spectra of SO-M showed reduction in crystallinity due to microencapsulation. After four weeks of storage, a moderate (∼12%) decrease in the EPA and DHA content and a low PV of 5.5±0.51meq/kg oil in SO-M demonstrated good oxidative stability. Satisfactory encapsulation efficiency (84±0.84%) and loading efficiency (67±0.51%) values, also demonstrated the suitability of Va-g-Ch for microencapsulation of sardine oil.

Evaluation of Requirements for Staging the Procedure of Reconstruction of Middle Ear After Canal Wall Down Mastoidectomy.

Cholesteatoma is a progressive destructive ear disease which can affect any age group. It has been found to be more severe in children and young adults. It erodes the surrounding bone of middle ear, mastoid and ossicles. It causes partial to total deafness, unpleasant smelling discharge, pain, tinnitus, vertigo and facial paralysis. It can even cause meningitis, brain abscess and death. The post-operative outcome of hearing, and the state of the reconstructed middle-ear cavity after concurrent and staged reconstruction of middle ear after canal wall down mastoidectomy was studied in 30 ears with middle-ear cholesteatoma. The reconstructed middle ear was re-aerated in 60.5 % of the cases, which was significantly higher than for the epitympanum (39.5 %). Tympanoplasty was successful in terms of hearing results in 68.9 % of all subjects and in 75.4 % of the ears having a re-aerated tympanic cavity, which was significantly better than the 38.5 % for ears in which the tympanic cavity was not re-aerated. The findings of recurrent cholesteatoma, tympanic atelectasis, and tympanic effusion were observed with significantly (p < 0.03) high incidence in ears with no re-aerated space in their reconstructed mastoid cavities. It was revealed that the post-operative outcome of this surgical technique was significantly related to the state of re-aeration of the reconstructed middle-ear cavity but not with either concurrent or staged reconstruction. Audiological results are same for both concurrent and staged reconstruction following canal wall down tympanomastoidectomy, and hence we reccommend that concurrent reconstruction is preferred in limited disease and staged reconstruction in severe disease.

Effect of curry leaf and clove bud essential oils on textural and oxidative stability of chill stored sutchi catfish fillets.

Effect of coating with curry leaf and clove essential oils (EO) on oxidative and textural stability of sutchi catfish fillets were evaluated during chilled storage. The changes in parameters associated with textural and lipid degradation was also evaluated to ascertain the interactive effect of polyphenols with muscle proteins. Further, the results were compared against vacuum and conventional polyethylene packaging practices. Prior to coating, the properties of antioxidants were evaluated in vitro based on total phenolic and flavonoid contents, 2, 2-diphenyl-1- picrylhydrazyl radical scavenging activity, inhibition of linoleic acid peroxidation, iron reducing power, and metal chelating ability. Coating with clove bud EO was found to be more effective in protecting the textural quality and retarding lipid oxidation of the fillets during chilled storage. Curry leaf EO was found to have only moderate effect. PRACTICAL APPLICATIONS: In addition to the well-studied antibacterial and antioxidant properties, plant polyphenols have become an intense focus of research for their ability to cross-link proteins that widens their applications for textural and functional modification of food and beverages. Currently, a number of carcinogenic chemicals such as ammonia and formalin are hazardously used to prevent texture deterioration in chilled fish associated with post-rigor changes and microbial reactions. This study evaluates the efficacy of polyphenols present in culinary herbs such as clove bud and curry leaf EO, in stabilising the texture of fish meat during chilled storage. From the results, it could be inferred that both the EO at 0.25% level mediated protein cross-linking/complexation and maintained textural integrity during chilled storage apart from exhibiting antioxidant activities.

Gelation and thermal characteristics of microwave extracted fish gelatin-natural gum composite gels.

In this study, the gelation and thermal characteristics of microwave extracted fish scale gelatin blended with natural gums such as gum arabic (AG), xanthan gum (XG), guar gum (GG), and tragacanth gum (TG) was evaluated. The nature of interaction and behavior of gelatin in presence of various gums was confirmed by particle size analysis, viscosity profile, FT-IR analysis and turbidity measurements. DSC data revealed that addition of AG, TG and GG remarkably improved the thermal stability of fish gelatin gel. The composite gels of TG, AG, and XG exhibited higher hardness and bloom strength values as compared to pure fish gelatin implying its textural synergy. Based on qualitative descriptive analysis, TG was found to be superior in improving the stability of fish gelatin gel, closely followed by AG. The results suggest that addition of these gums can reduce syneresis and retard melting of gelatin gels at ambient temperature, which are otherwise soft and thermally unstable.

Dietary supplementation of thiamine and pyridoxine-loaded vanillic acid-grafted chitosan microspheres enhances growth performance, metabolic and immune responses in experimental rats.

In the present investigation, the effect of dietary supplementation of thiamine and pyridoxine loaded vanillic acid-grafted chitosan microspheres (TPVGC) on growth, metabolic and immune responses in Wistar strain albino rats was studied. Eight experimental groups, namely four groups each for male and female rats were fed with 0, 0.4, 0.8 and 1.6% of TPVGC in the diet. At the end of 45days feeding trials, both male and female rats supplemented with TPVGC had higher weight gain% and specific growth rate than the control groups. Significantly (p<0.05) lower blood glucose level and higher respiratory burst activity were recorded in the treatment groups than the control groups of both male and female rats. Activity of metabolic enzymes (aspartate amino transferase, alanine aminotransferase, alkaline phosphatase and acid phosphatase) and antioxidant enzymes (superoxide dismutase, catalase and glutathione S-transferase) were significantly higher (p<0.05) in the control groups and a decreasing trend in the same was observed with a gradual increase in the inclusion level of TPVGC in the diet of the treatment groups. However, a reverse trend was observed for acetylcholine esterase. It was inferred that dietary supplementation of thiamine and pyridoxine loaded vanillic acid-grafted chitosan enhanced the growth performance, metabolic and immune responses in the animal-model.