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5.3 Viral Classification: ICTV classification, Baltimore Classification and their comparison

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5.3 Viral Classification: ICTV classification, Baltimore Classification and their comparison 5.3.1 ICTV Classification Overview The International Committee on Taxonomy of Viruses (ICTV) is the global authority responsible for the classification and nomenclature of viruses. Established in 1966, the ICTV aims to develop a universal taxonomic framework for viruses based on their evolutionary relationships, ensuring consistency in naming and classification across the scientific community. Key Aspects of ICTV Classification Hierarchical Structure The ICTV classifies viruses into a hierarchical structure that includes the following taxonomic ranks: Order: Ortervirales Family: Retroviridae Genus: Lentivirus Species: Human immunodeficiency virus 1 (HIV-1) Criteria for Classification Viruses are classified based on several criteria, including: Type of nuclei...

Concentration and purity of the extracted DNA using spectrophotometry

To determine the concentration and purity of the extracted DNA using spectrophotometry, you would typically use a UV-Vis spectrophotometer. Here's a general overview of the process: Materials: Extracted DNA sample UV-Vis spectrophotometer Cuvettes or microvolume plates compatible with the spectrophotometer Distilled water (for blank measurements) Spectrophotometry software (for data analysis) Procedure: Prepare the Spectrophotometer : Turn on the spectrophotometer and allow it to warm up according to the manufacturer's instructions. Set the wavelength to 260 nm, which corresponds to the absorbance maximum of nucleic acids. Blank Measurement : Prepare a blank solution containing only distilled water in a cuvette or microvolume plate. Place the blank solution in the spectrophotometer and zero the instrument using the "Blank" or "Zero" function. DNA Sample Measurement : Dilute the extracted DNA sample to an appropriate concentration if necessary, ensuring that ...

Scrub typhus

Scrub typhus is a bacterial infection caused by the bacterium Orientia tsutsugamushi . It is transmitted to humans through the bite of infected larval-stage trombiculid mites, also known as chiggers. Scrub typhus is endemic to rural areas in the Asia-Pacific region, including countries like India, China, Japan, South Korea, and parts of Southeast Asia. Here are the key details about scrub typhus: Causative Agent : Scrub typhus is caused by the bacterium Orientia tsutsugamushi , a member of the Rickettsiaceae family. The bacterium is an obligate intracellular parasite, meaning it can only replicate within host cells. O. tsutsugamushi is primarily transmitted to humans through the bite of infected trombiculid mites (chiggers) during their larval stage. Transmission : Humans typically acquire scrub typhus through the bite of infected larval-stage chiggers, which are found in areas of dense vegetation, such as forests, grasslands, and scrublands. When an infected chigger bites a human, it...

Variants of SARS-CoV-2 virus

Since its emergence in late 2019, the SARS-CoV-2 virus, responsible for COVID-19, has undergone several genetic mutations, leading to the emergence of various variants. Here is an overview of notable variants of SARS-CoV-2 identified from its origin to 2024: Original Wuhan Strain : The initial strain of SARS-CoV-2, also known as the Wuhan or wild-type strain, was first identified in Wuhan, China, in late 2019. This strain served as the baseline for subsequent variants. Alpha Variant (B.1.1.7) : Identified in the United Kingdom in September 2020, the Alpha variant is characterized by multiple mutations in the spike protein, including N501Y, associated with increased transmissibility. It quickly spread to other countries and became a dominant variant in many regions. Beta Variant (B.1.351) : First identified in South Africa in May 2020, the Beta variant contains mutations in the spike protein, including E484K, which may affect antibody recognition and vaccine efficacy. It has been associ...