Transformation, conjugation and transduction are the methods of horizontal gene transfer in bacteria.
Conjugation:
orderly, deliberate transfer of DNA from one cell to another; programmed
by specialized genes and organelles.
Transformation:
uptake of environmental DNA into a cell.
Transduction:
transfer of DNA from one cell to another mediated by a virus.
Mucormycosis is a fungal infection caused by
molds (mucormycetes). These fungi are present in soil and in decaying organic
matter e.g., compost, rotten woods, dungs etc. Spores of these fungi are present
throughout in the environment. When any person with health issues (e.g., diabetes
etc.) and weak immunity come in contact with fungal spores they get mucormycosis.
Types
of mucormycosis
1. Rhinocerebral (sinus and
brain) mucormycosis: this infection spread to the
brain from sinuses and most common in persons with uncontrolled diabetes and in persons who have had a
kidney transplant.
Symptoms- One-sided
facial swelling, headache, nasal or sinus congestion, black lesions on nasal
bridge or upper inside of mouth that quickly become more severe, fever.
2. Pulmonary (lung)
mucormycosis: this is the most common infection in cancer
patient and in person who have had organ transplant.
Symptoms- Fever,
Cough, Chest pain, shortness of breath.
3. Gastrointestinal
mucormycosis: this infection is common in
lower age group people who have weak immunity.
Symptoms- Abdominal
pain, nausea and vomiting, gastrointestinal bleeding.
4. Cutaneous (skin) mucormycosis: spores enter in the body through skin. When any break in the
skin occurs (by injury etc.) spores of fungi get entered in the body through
broken skin.
Symptoms- Blisters
or ulcers, infected area may turn black, pain excessive redness, swelling
around the wound.
5. Disseminated mucormycosis: in this
infection spores transport through bloodstream to different organs. Brain is the commonly affected part; it can also affect spleen and
heart.
Symptoms- Mental
status changes, coma.
Causative
agent:
Rhizopus species, Mucor species, Rhizomucor species, Syncephalastrum species, Cunninghamella
bertholletiae, Apophysomyces species, and Lichtheimia (formerly Absidia) species.
Treatment
Mucormycosis is treated by antifungal medicine like amphotericin B (intravenous),
posaconazole (intravenous/oral), or isavuconazole (intravenous/oral). Often,
mucormycosis needed surgery to remove the infected part.
Nowadays, everyone is talking about 2-deoxy-D-glucose (2-DG).
Institute
of Nuclear Medicine and Allied Sciences (INMAS), a lab of Defense Research and
Development Organization (DRDO) has developed the therapeutic application of
2-DG against COVID-19 in collaboration with its industry partner Dr. Reddy’s
Laboratories (DRL). It is being claimed that 2-DG will help COVID-19 patients in fast recovery. The results of its clinical
trial were very positive and encouraging therefor, DCGI approves anti-COVID drug developed by DRDO for
emergency use.
When 2-DG is presented in cells it phosphorylated by hexokinase to 2-deoxy-D-glucose-6-phosphate (2-DG-P). 2-DG-P is not recognized by glycolytic enzymes and further metabolism of glucose cannot occur. We can say that 2-DG is a glycolytic inhibitor. Consequently, energy (ATP) production is stopped because end product of glycolysis (pyruvic acid) is the fuel for further energy producing pathways. Therefore, accumulation of 2-DG-P and depletion of ATP occur. In the same way it acts on COVID-19 infected cells. It accumulates in the virus infected cells and prevents virus growth by stopping viral synthesis and energy production.
Some images are attached here released by Press Information Bureau, Government of India.
Protein structure is stabilized by following interactions:
Covalent bond: Covalent bonds are formed when two atoms share equal electrons. Amino acids linked with each other through covalent peptide bonds and from dipeptide, tripeptide, oligopeptide and polypeptide. Covalent bonds are important to maintain the primary structure of protein.
Covalent disulphide bridges (-S-S-): Sulphur containing amino acid (cysteines) are involved in forming covalent disulphide bonds and play a pivotal role to maintain the tertiary structure of proteins.
Electrostatic interaction: This type of interactions is occur between oppositely charged molecules. in protein electrostatic interaction occur due to side chains of amino acids. Generally electrostatic interactions are found in tertiary and quaternary structure of proteins, and these interactions occur through their oppositely charged side chains (e.g., lysine and aspartic acid).
Hydrogen bond: Hydrogen bonds formed between hydrogen and electronegative atoms e.g., oxygen and nitrogen. Hydrogen bonds are the main reason behind the great stability of secondary, tertiary and quaternary structure of proteins.
van der Waals bonds: When the force of attraction and repulsion are equal it is known as London dispersion forces; and weak interactions resulting from this dispersive force are known as van der Waals bonds. These bonds are important in maintaining the three-dimensional structure of protein.
Hydrophobic bonds: Side chains of non-polar amino acids like valine etc. are involved in hydrophobic interactions. This interaction helps to minimize the contact between water molecule and side chains of non-polar amino acids. This provide stability to protein structure and important in folding.
Co-ordinate bond: Such type of interaction occur because in only one atom share the pair of electrons which are involve in bonding. Coordinate bond is found in metalloprotein.
