Virology and Microbiology

Vaccine is a biological preparation that provides Active acquired immunity to a specific disease. Vaccination is the most effective method of preventing infectious diseases. There are different types of vaccines which contain Inactivated micro-organisms (polio vaccine), attenuated micro-organisms (BCG vaccine), Inactivated Toxic compounds. Vaccines can interfere when two or more vaccines mixed together. Varicella vaccine is rarely associated with complications in Immuno deficient individuals.

Drug-drug interactions occur when a drug interacts with another drug and modify the way one or both of the drugs act in the body, or cause side effects. Hepatitis E has become a significant public health concern, as well as sporadic cases of acute hepatitis in developed countries. It is nothing but infection of the liver which is caused by different viruses such as hepatitis A to hepatitis E. Hepatitis E virus is still considered an emerging pathogen in developing countries.

Rhinovirus, coronavirus and adenovirus are the leading causes of the common cold. Upper Respiratory Infections spread from one person to another through aerosol droplets and direct hand-to-hand contact. Influenza viruses infect the upper respiratory system and even spread to the lungs causing pneumonia. Infection is the capture of an organism's body tissues by disease causing agents and the reaction of host tissues to these organisms and the toxins they produce. In childhood viral infections are rarely fatal, and are almost never serious. Infectious diseases in infants are caused by infectious agents like viruses, bacteria, nematodes, arthropods such as ticks, fungi like ringworm, and other macro parasites.

Viruses are only able to replicate themselves by confiscating the reproductive apparatus of cells and making them reproduce the virus's genetic structure instead. There are different life cycle process like viral entry, viral replication, viral shedding, and viral latency. Virotherapy is a treatment using biotechnology in which viruses convert into therapeutic agents by reprogramming viruses to treat diseases. There are different branches in Virotherapy like Oncolytic Virotherapy, viral gene therapy, viral immunotherapy. 

 Virus Evolution

The way viruses reproduce in their host cells makes them particularly susceptible to the genetic changes that help to drive their evolution. The RNA viruses are especially prone to genetic changes. In host cells there are mechanisms for correcting mistakes when DNA replicates and these kick in whenever cells divide. The genetic material inside the virus plays a major role in how rapidly a virus mutates, which in turn can impact how the illness can spread in the population. Viruses that replicate through DNA use the same mechanisms the host cell uses to create its own DNA. Many viruses (for example, influenza A virus) can shuffle their genes with other viruses when two identical strains infect the same cell. This phenomenon is called genetic shift.

Anti-virulence is the concept of blocking virulence factors, which are produced by viruses and enable them to achieve inhibition of the host’s immune response. These factors are used to promote colonization of the host. A major group of virulence factors are proteins that can control the activation levels of GTPases. Immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen is known as Cell-mediated Immunity. CD4 cells provide protection against different pathogens.

The hepatitis C virus particle consists of a core of genetic material (RNA) enclosed by an icosahedral protective shell of protein, and further covered in a lipid envelope of cellular origin. The p7 protein is nonessential for viral genome replication but plays a critical role in virus morphogenesis. Neurotropic viruses are said to be Neuroinvasive if it is capable of entering the nervous system and Neurovirulent if it is capable of causing disease within the nervous system. Neurotropic viruses have been reported to lead to various neurodegenerative diseases

Plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. These are pathogenic to higher plants. The first virus to be discovered was Tobacco mosaic virus (TMV). Viruses cause an estimated US$60 billion loss in crop yields worldwide every year. Aquatic bacteriophages are viruses that live as obligate parasitic agents in marine bacteria such as cyanobacteria. Aquatic micro-organisms are able to prepare their own food through Photosynthesis.

Plaques are clear zones formed in a lawn of cells due to lysis by phage. Lysogens begin to grow in the middle of the plaque, giving the plaque a turbid. The morphology of the plaque depends upon the phage, the host, and the growth conditions. Virus quantification is counting the number of viruses in a particular volume to determine the virus concentration. The plaque assay can be used to refine a clonal population of virus. An Oncolytic virus is a virus that specially infects and kills cancer cells. Viral oncology is concerned with treatment of human cancers / tumors with virus particles. Certainly, the infectious nature of specific tumors has important implications in their prevention, diagnosis, and therapy. In the 21st Century, the research on viral oncology field continues to be dynamic, with new significant and original studies on viral Oncogenesis and as a translational research from virology for the treatment of cancer.

Human Papillomavirus Infection (HPV) is caused by human papillomavirus, it is a DNA virus from the family Papillomavirus. More than 40 types of infections are transmitted through sexual contact and infect the anus and genitals. Risk factors for insistent HPV infections include early age of first sexual intercourse, multiple partners, smoking, and poor Immune function. HPV is typically spread by sustained direct skin-to-skin contact with vaginal and anal sex being the most common methods. Occasionally, it can spread from a mother to her baby during pregnancy. It does not spread via common items like toilet seats. People can become infected with more than one type of HPV. HPV only affects humans.

Monoclonal antibodies are antibodies that are made by identical immune cells. These can have monovalent affinity, in that they bind to the same epitope. In divergence, polyclonal antibodies bind to multiple epitopes and made by several different plasma cell lineages. These antibodies are secreted by different B cell lineages and are used for autoimmune diseases. Antigen prompts the B-lymphocytes to produce IgG Immunoglobulin’s.

About 24 million people in the United States are affected by an autoimmune disease.

Paleovirology is the term used to describe the study of viruses which cannot leave behind physical fossils. Virion structural protein derived from the amino-terminal domain of the Gag polyprotein. Phylogenetic analysis of Endogenous Viral Elements (EVEs) across multiple host species exhibit novel information about the evolution of diverse virus groups. EVEs have been adopted as inhibitors of viral infection.Viral infection occurs when an organism's body is invaded by pathogenic viruses, and virions attach to and enter susceptible cells. Viral infection is usually detected by clinical monitoring, for instance severe muscle and joint pains preceding fever, skin rash. Viruses are Intracellular obligate parasites that they cannot replicate their genes without the help of a living cell. Certain proteins on the virus particle must fit particular receptor sites on the particular host cell surface. Host cell provides the energy & system for the synthesis of viral proteins & nucleic acids. 

 Molecular biology

Molecular virology is the study of viruses on a molecular level. Viruses are sub-microscopic parasites that replicate inside host cells. Pure Microbiology provides a broad platform of a large plethora of research and more new insights into different areas of Molecular biology. Molecular genetics has been among the most prominent sub-fields of molecular biology. Molecular techniques are used to theorize historical attributes of populations (or) species, as in fields in evolutionary biology like population genetics and Phylogenetics.

Epidemiology
Viral epidemiology is the branch of medical science that deals with the frequency and spread of viruses in populations over time. It is used to break the chain of infection in populations during outbreaks of viral diseases. Host, virus and environmental factors are monitored to determine the dynamics of viral infections, the ultimate goal of which is to devise intervention strategies. Transmission of viruses can be vertical, means from mother to child (or) horizontal, means from person to person. The rate of transmission of viral infections depends on factors that include population density, the number of susceptible individuals, the quality of healthcare and the weather.