Publications by authors named "A Archana"

27 Publications

Neutralizing antibody response against subcutaneously injected bacteriophages in rabbit model.

Virusdisease 2021 Mar 10;32(1):38-45. Epub 2021 Mar 10.

Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, 221005 India.

Bacteriophage therapy is currently experiencing a renaissance. Therapeutic efficacy of bacteriophages depends on phage-bacterial and phage-host interactions. The appearance of neutralizing anti-phage antibody has been speculated to be one of the few reasons for bacteriophage therapy's failure. This study aimed to know whether there is a rise in the neutralizing antibody on the parenteral injection of bacteriophages in an animal model. This study included bacteriophages against five different bacteria, namely , , , and These bacteriophages were isolated, propagated and purified. Bacteriophage specificity was confirmed by spot testing on the respective bacterial lawn. Weekly subcutaneous injection of purified bacteriophages (10PFU) was given to five rabbits for six weeks. Blood samples were collected before administering the next dose every week. The antibody response was tested by phage neutralization followed by plaque assay by using double agar overlay method. The rise in anti-phage neutralizing antibodies was observed usually after the 3 week after immunization. Complete neutralization of bacteriophages could be seen between 3 and 5 weeks after immunization. A further rise in bacteriophage counts (PFU), especially on 1:1000 and 1:2000 serum dilutions, could be noticed by the end of 6th week against most bacteriophages injected. Background anti-phage neutralizing antibodies were observed against bacteriophage specific to However, it was absent against bacteriophages specific to other four bacteria. Bacteriophage interacts with mammalian host and induces anti-phages neutralizing antibody production. However, neutralization of phage depends on repeated administration and duration of therapy. The significant rise in neutralizing antibody could be seen at the end of 3rd week. Therefore, bacteriophage can be effectively used in acute cases where therapy duration is less than 2 weeks. However, for prolonged therapy, bacteriophage cocktail of different antigenicity may be suggested.
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http://dx.doi.org/10.1007/s13337-021-00673-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8093364PMC
March 2021

Modification of fatty acid profile and biosynthetic pathway in symbiotic corals under eutrophication.

Sci Total Environ 2021 Jun 22;771:145336. Epub 2021 Jan 22.

School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong Special Administrative Region; Swire Institute of Marine Science, The University of Hong Kong, Cape d'Aguilar Road, Shek O, Hong Kong Special Administrative Region. Electronic address:

Symbiotic corals receive energy not only by ingesting food (e.g. plankton, inorganic/organic matter, i.e. heterotrophy), but also by endosymbiosis, which supplies photosynthates (dissolved inorganic carbon, i.e. autotrophy). These two sources of energy have distinct fatty acid (FA) profiles, which can be used to differentiate corals by their primary feeding mode. FA profiles have been applied as biomarkers to evaluate the quality of nutrition in the midst of environmental change. However, species-specific responses of coral FA profiles and biosynthetic pathway under cultural eutrophication are still unknown. We collected two coral species (Acropora samoensis, Platygyra carnosa) from sites with different levels of eutrophication to test for variations in FA profiles. Gas Chromatography-Mass Spectrometry (GC-MS) was performed to identify FA profiles and quantify their concentration. Our main findings are threefold: 1) chronic eutrophication inhibits corals' ability to synthesize essential FA; 2) PUFA:SFA ratio and certain FA biomarkers or their pathway can be successfully utilized to determine the relative degree of autotrophy and heterotrophy in corals; 3) under eutrophication, different FA profiles of coral host tissue are attributed to different feeding strategies. Thus, our research provides significant new insights into the roles of FA as a risk assessment tool in coral reef ecosystems under the pressure of eutrophication.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145336DOI Listing
June 2021

A 5-year-old girl with bony deformities and disproportionate short stature: Answers.

Pediatr Nephrol 2021 Mar 17. Epub 2021 Mar 17.

Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, 605006, India.

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http://dx.doi.org/10.1007/s00467-021-05038-3DOI Listing
March 2021

A 5-year-old girl with bony deformities and disproportionate short stature: Questions.

Pediatr Nephrol 2021 Mar 17. Epub 2021 Mar 17.

Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, 605006, India.

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http://dx.doi.org/10.1007/s00467-021-05031-wDOI Listing
March 2021

Investigating the link between Pearl River-induced eutrophication and hypoxia in Hong Kong shallow coastal waters.

Sci Total Environ 2021 Jun 2;772:145007. Epub 2021 Feb 2.

Department of Earth Science, Swire Institute of Marine Science, The University of Hong Kong, Hong Kong, China. Electronic address:

We present geochemical analysis of 75 surface water samples collected in 2016 in Hong Kong coastal waters. We found that nitrogen distribution around Hong Kong can be characterized by two regimes driven by the influence of the Pearl River: 1) a regime where nitrate is the dominant species of nitrogen, associated with lower salinity and more faecal coliform and 2) a regime where dissolved organic nitrogen is dominant, associated with higher salinity and fewer faecal coliform. While the impact of the Pearl River on Hong Kong coastal waters is well characterized, we used the sharp contrast between the nitrogen regimes to produce new evidence about the role of the Pearl River on the generation of local hypoxia in Hong Kong. The impact of nitrate originating from the Pearl River on the generation of hypoxia in Hong Kong might be less important than previously thought, as no sign of eutrophication was found within the zones dominated by dissolved organic nitrogen and an historical decoupling of surface processes and bottom water oxygenation was observed. Moreover, we measured elevated ammonium levels and rapid cycling of ammonium and dissolved organic nitrogen in Victoria Harbour suggesting local sources, such as wastewater, might be rapidly oxidized and thus play an important role in the consumption of oxygen locally. A first-order calculation highlighted the potential for wastewater to drive the observed seasonal decline in oxygen. Taken together, these evidences suggest that eutrophication might not be the primary driver in the generation of seasonal hypoxia and that oxidation of ammonium released locally might play a bigger role than initially thought.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145007DOI Listing
June 2021