Post-COVID-19 HSV encephalitis: a review.

BACKGROUND: Herpes simplex virus encephalitis (HSVE) is one of the most common infectious causes of sporadic encephalitis. Coronavirus disease (COVID-19) has been associated with immune dysregulation of the host that might increase the risk of infections like HSVE following SARS-CoV-2 infection. There is paucity of literature on post COVID-19 HSVE. This study was conducted with the aim of analyzing the clinical presentation, brain imaging, and outcome of patients presenting with HSVE within 6 weeks of COVID-19 and providing a comprehensive review on the possible mechanisms of post-COVID-19 HSVE. METHODS: This observational study included patients who had laboratory-confirmed HSVE (type 1 or type 2) and a history of COVID-19 within the previous 6 weeks. Patients were followed up for 3 months. RESULTS: Eight patients were included and all of them had type 1 HSVE. The mean latency of onset of neurological symptoms from being diagnosed with COVID-19 is 23.87 days and a majority of the patients have received injectable steroids with a mean duration of 6.5 days. Behavioral abnormality was the commonest neurological presentation and typical brain imaging involved T2 FLAIR hyperintensities of the medial temporal lobes. All patients received intravenous acyclovir 10 mg/kg every eight hourly for atleast 14 days. One patient with concomitant rhinocerebral mucormycosis succumbed while the majority had a complete recovery. CONCLUSION: Possible immune dysregulation in COVID-19 may increase the susceptibility of HSVE in patients with a history of recent SARS-CoV-2 infection. The clinical manifestations and laboratory findings of HSVE in such patients are similar to typical HSVE.

Tumour necrosis factor-alpha and nitric oxide response in different categories of tuberculosis patients.

OBJECTIVE: To compare the magnitude of tumour necrosis factor alpha (TNF-α) and nitric oxide (NO) response in different categories of active tuberculosis (TB) patients by ex vivo experiment. DESIGN: New, relapsed (recurrent), miliary and pleural effusion TB cases were recruited with matched healthy controls. TNF-α and NO were measured from the culture supernatant of peripheral blood monocytes derived from cases and controls with and without challenge with live Mycobacterium tuberculosis H37Rv. RESULTS: TNF-α and NO production varied significantly among the different categories of TB patients. The magnitude was highest among patients with pleural effusion and lowest in miliary TB cases. In between, progressive decreases in response were noted in new and relapse cases. Overall, positive correlations between TNF-α and NO were noted among the diseased and healthy groups. CONCLUSION: Distinct TNF-α and NO levels appear to be associated with different clinical forms of TB and might help to assess prognosis and contribute to a better understanding of underlying immunopathological mechanisms.

Water stress amelioration and plant growth promotion in wheat plants by osmotic stress tolerant bacteria.

Soil microorganisms with potential for alleviation of abiotic stresses in combination with plant growth promotion would be extremely useful tools in sustainable agriculture. To this end, the present study was initiated where forty-five salt tolerant bacterial isolates with ability to grow in high salt medium were obtained from the rhizosphere of Triticum aestivum and Imperata cylindrica. These bacteria were tested for plant-growth-promoting rhizobacteria traits in vitro such as phosphate solubilization, siderophore, ACC deaminase and IAA production. Of the forty-five isolates, W10 from wheat rhizosphere and IP8 from blady grass rhizosphere, which tested positive in all the tests were identified by morpholological, biochemical and 16SrDNA sequencing as Bacillus safensis and Ochrobactrum pseudogregnonense respectively and selected for in vivo studies. Both the bacteria could promote growth in six varieties of wheat tested in terms of increase in root and shoot biomass, height of plants, yield, as well as increase in chlorophyll content. Besides, the wheat plants could withstand water stress more efficiently in presence of the bacteria as indicated by delay in appearance of wilting symptoms increases in relative water content of treated water stressed plants in comparison to untreated stressed ones, and elevated antioxidant responses. Enhanced antioxidant responses were evident as elevated activities of enzymes such as catalase, peroxidase, ascorbate peroxidase, superoxide dismutase and glutathione reductase as well as increased accumulation of antioxidants such as carotenoids and ascorbate. Results clearly indicate that the ability of wheat plants to withstand water stress is enhanced by application of these bacteria which also function as plant growth promoting rhizobacteria.

Evaluation of Ochrobactrum anthropi TRS-2 and its talc based formulation for enhancement of growth of tea plants and management of brown root rot disease.

AIM: To evaluate Ochrobactrum anthropi TRS-2 isolated from tea rhizosphere and its talc based formulation for growth promotion and management of brown root rot disease of tea. METHODS AND RESULTS: Ochrobactrum anthropi TRS-2, isolated from tea rhizosphere could solubilize phosphate, produce siderophore and IAA in vitro and also exhibited antifungal activity against six test pathogens. Application of an aqueous suspension of O. anthropi to the rhizosphere of nursery grown tea seedlings of five varieties of tea (TV-18, T-17, HV-39, S-449, UP-3 and) led to enhanced growth of the treated plants, as evidenced by increase in height, in the number of shoots and number of leaves per shoot. Treatment with O. anthropi also decreased brown root rot of tea, caused by Phellinus noxius. Multifold increase in activities of chitinase, beta-1,3-glucanase, peroxidase and phenylalanine ammonia lyase in tea plants was observed on application of O. anthropi to soil followed by inoculation with P. noxius. A concomitant increase in accumulation of phenolics was also obtained. Further, talc based formulation of O. anthropi was prepared and its survival determined every month up to a period of 12 months. Ochrobactrum anthropi could survive in the formulation up to a period of 9 months with a concentration of 7.0 log(10) CFU g(-1), after which there was a decline. Talc formulation was as effective as aqueous suspensions in both plant growth promotion and disease suppression. CONCLUSION: Ochrobactrum anthropi, either in aqueous suspension or as talc formulation induced growth of tea plants and suppressed brown root rot disease. It induced defense responses in tea plants. SIGNIFICANCE AND IMPACT OF THE STUDY: Ochrobactrum anthropi and its talc based formulation can be considered as an addition to available plant growth promoting rhizobacteria (PGPR) currently being used for field application. The present study offers a scope of utilizing this bacterium for growth promotion and disease management which would help in reduction of the use of chemicals in tea plantations.

Characterization of antimicrobial compounds from a common fern, Pteris biaurita.

Methanol extract was prepared from the fronds of Pteris biaurita and partial purification was done by solvent partitioning with diethyl ether and ethyl acetate, followed by hydrolysis and further partitioning with ethyl acetate. The three fractions, thus obtained were bioassayed separately against five test fungi--Curvularia lunata, Fomes lamaoensis, Poria hypobrumea, Fuasrium oxysporum and a bacterium--Bacillus pumilus, by spore germination, radial growth and agar cup techniques. Results revealed that ethyl acetate fraction (III) contained the active principle. TLC plate bioassay of the active fraction revealed inhibition zone at an Rf of 0.5-0.65. Silica gel from this region was scraped, eluted in methanol and subjected to UV-spectrophotometric analysis. An absorption maxima of 278 nm was recorded. HPLC analysis of TLC-eluate revealed a single peak with retention time of 8.1 min. GC-MS analysis revealed six major peaks in the retention time range of 7.2-10.9 min. Comparison with GC-MS libraries revealed that the extracts may contain a mixture of eicosenes and heptadecanes.

Biochemical responses of Camellia sinensis (L.) O. Kuntze to heavy metal stress.

Three heavy metals-mercury (II), copper (II) and nickel (II), each at a concentration of 10 and 100 micrograms/ml, were tested for their effects on various biochemical constituents of tea leaves. Both NI (II) and Hg (II) decreased the phenolic contents, while Cu (II) increased it to some extent. The metal treatments enhanced the activity of phenyl alanine ammonia lyase (PAL), while the activity of poly phenol oxidase (PPO) showed a decline. Heavy metal stress also decreased the chlorophyll content of the leaves, along with a significant reduction in Hill activity. Proline content increased significantly in all treatments.

Detection of cross-reactive antigens shared by Fusarium oxysporum and Glycine max by indirect ELISA and their cellular location in root tissues.

Pathogenicity test of Fusarium oxysporum on ten cultivars of soybean revealed Soymax and Punjab-1 to be most resistant while JS-2 and UPSM-19 were most susceptible. Antigens were prepared from the roots of all the ten varieties of soybean and the mycelium of F. oxysporum. Polyclonal antisera were raised against the mycelial suspension of F. oxysporum and the root antigen of the susceptible cultivar UPSM-19. Cross reactive antigens shared by the host and the pathogen were detected first by immunodiffusion. The immunoglobulin fraction of the antiserum was purified by ammonium sulfate precipitation and DEAE-Sephadex column chromatography. The immunoglobulin fractions were used for detection of cross-reactive antigens by enzyme-linked immunosorbent assay. In enzyme-linked immunosorbent assay, antigens of susceptible cultivars showed higher absorbance values when tested against the purified anti-F. oxysporum antiserum. Antiserum produced against UPSM-19 showed cross-reactivity with the antigens of other cultivars. Indirect staining of antibodies using fluorescein isothiocyanate indicated that in cross-sections of roots of susceptible cultivar (UPSM-19) cross-reactive antigens were concentrated around xylem elements, endodermis and epidermal cells, while in the resistant variety, fluorescence was concentrated mainly around epidermal cells and distributed in the cortical tissues. CRAs were also present in microconidia, macroconidia and chlamydospores of the fungus.

Antagonism of Erwinia herbicola towards Leptosphaeria maculans causing blackleg disease of Brassica napus.

Phyllosphere micro-organisms of Brassica napus were isolated and their antagonism against Leptosphaeria maculans, causal agent of blackleg disease, was tested in vitro. In paired culture, Erwinia herbicola was found to be highly antagonistic to L. maculans. Bioassay of the culture filtrate of the bacterium against the test fungus revealed that Erw. herbicola secretes an antifungal substance into the culture medium. This substance was partially thermolabile and markedly reduced the germination and germ tube length of L. maculans. Aqueous bacterial suspensions and cold-sterilized culture filtrates, when applied to the seedlings prior to inoculation, significantly reduced the severity of blackleg disease.

An immunogold assay system for the detection of antigen or antibody.

A colloidal gold-based semi-quantitative manual immunoassay method for the detection of antibody or antigen has been developed. The colloidal gold particles are coated with an organic reagent which, in turn, is attached to the antibody by covalent bonds. The antibody or the antigen are immobilized on simple chromatography paper. The paper strips are developed with an appropriate immunogold reagent in a test tube in the presence of urine (Pregnancy or Ovulation test) or serum (Rubella test). The mixture migrates up the strips towards the test band. A purple band develops which indicates the presence of the corresponding antigen (Pregnancy, Ovulation test) or antibody (Rubella test). In this format, 50 mIU or more of hCG in urine can be detected in 5 minutes or less, and antibody to Rubella virus at an HAI titer equivalent of 8 or above in serum can be detected in 10 minutes or less. These test kits, known as Result Plus test systems, are simple, rapid, highly sensitive, and require no instruments to perform.

Synthesis and antilipolytic activities of quinolyl carbanilates and related analogues.

A series of quinolyl carbanilates was prepared and tested as antilipolytic agents. These compounds inhibited production of glycerol from rat adipocytes and inhibited liberation of free fatty acids from triolein by canine cardiac triglyceride lipases. An extensive structure-activity relationship study indicated that 8-quinolyl 4-methoxycarbanilate (1) contained features necessary for maximum potency in vitro. Substituting a benzofuranyl group for the quinolyl group of 1 provided the most interesting compound on the basis of both potency and structural novelty. 7-Benzofuranyl 4-methoxycarbanilate (44) has IC50's of 16 and 0.3 microM in the myocardial lipase and rat adipocyte assays, respectively. In vivo, compound 44 was orally active as an inhibitor (97% at 25 mg/kg) of lipolysis in the rat.

Substituted arylmethyl phenyl ethers. 1. A novel series of 5-lipoxygenase inhibitors and leukotriene antagonists.

A series of new substituted arylmethyl phenyl ethers has been prepared. These compounds were tested as inhibitors of 5-lipoxygenase (5-LO) in rat neutrophils, in vitro antagonists of leukotriene-induced contraction of guinea pig (GP) lung parenchymal strips, and inhibitors of slow reacting substance of anaphylaxis (SRS-A) mediated bronchospasm in the GP in vivo. Most representatives of this new class of potential antiallergic/antiinflammatory agents showed potent inhibition of 5-LO activity in rat PMNs. The most potent compound, 2-[[3-(1-hydroxyhexyl)phenoxy]-methyl]quinoline (33), had an I50 of 0.12 microM in the rat PMN 5-LO assay and an I50 of 3.6 microM in the leukotriene-induced contraction of GP lung parenchymal strips, and it also showed 91% inhibition of SRS-A-mediated bronchospasm in the GP in vivo at 10 mg/kg, administered intraduodenally. Some of the compounds in this series were also leukotriene antagonists in vitro, and several of them showed in vivo activity against SRS-A-mediated bronchospasm in the GP.

Role of rhizobitoxine in protecting soybean roots from Macrophomina phaseolina infection.

Bacterization of soybean seeds or roots with Rhizobium japonicum significantly reduced charcoal rot disease caused by Macrophomina phaseolina . Rhizobium japonicum inhibited the growth of M. phaseolina on both liquid and solid media. Replacement of nutrient medium with culture filtrate of R. japonicum significantly reduced mycelial growth of M. phaseolina . Whole culture extracts of R. japonicum yielded a toxic substance which was identified as rhizobitoxine after chromatographic, ultraviolet, and infrared spectrophotometric analyses. This compound also was detected in the roots of soybean inoculated with either R. japonicum alone or in combination of R. japonicum and M. phaseolina . Dosage response curves with rhizobitoxine showed it to be antifungal. The possible role of rhizobitoxine in protecting soybean roots from M. phaseolina infection is discussed.