BIOL 2460 Chapter 6 - Tagged

Acellular Pathogens

Pathogens that do not have cell(s), can be seen via TEM or SEM, and possess genetic material; includes viruses, viroids, virusoids, and prions.

Viruses

Acellular obligate intracellular parasites that hijack host cellular machinery to reproduce (virions) and do not belong to the tree of life.

what are componects of viruses

components of viruses include; capsid (capsomere subunit), genomic material (RNA or DNA), envelope (if present), and spikes (protein if present)

Bacteriophage

Viruses that specifically infect bacteria.

Bacteriophage infection can only be obtained via…

Direct contact (infected individual), Fomite (eating utensil, doorknobs, bedding etc), Mechanical vector - organism carries virus inside (ticks,mosquitos, bitting flies,etc)

what are virons ?

viral particles assembled in infected host host cell, with a ranging size of 20nm - 900nm

Lytic Cycle

The process by which virulent phages kill the host cell through lysis after replication.

Lysogenic Cycle

A viral life cycle where temperate phages integrate into the host genome and can remain dormant until induced.

Hemagglutination Assay

A test that detects viruses by observing the agglutination of red blood cells.

Viroids

Virus-like agents composed of circular RNA that can self-replicate, lacking a protein coat.

Virusoids

Non-self-replicating subviral particles that require a helper virus for replication.

Prions

Infectious agents consisting of misfolded proteins that cause other proteins to misfold, leading to diseases like mad cow disease, and CJD.

how are prions transmitted ?

transmitted between animals, animals to humans (via consumption of meat), and human to human via heredity. IT’S ALSO VERY DIFFICULT TO DESTROY (no treatment)

Nucleic Acid Amplification Test (NAAT)

A diagnostic method for detecting unique viral sequences, commonly using PCR (polymerase chain reaction).

Chronic Infections

Long-lasting infections where the host cannot successfully eliminate the virus, e.g., HIV.

Capsid

The protein coat surrounding the genomic material of a virus.

Viral Morphology

The structure and form of viruses, which can be classified by capsid shape and presence of an envelope.

Viral Growth Curve

The progression of virus propagation over time, typically including phases like inoculation, eclipse, burst, and burst size.

Epidemiology

The study and analysis of the distribution, patterns, and determinants of health and disease conditions in defined populations.

Provirus

Integrated viral genome in the host DNA as a result of retroviral infection.

International Committee on Taxonomy of Viruses (ICTV)

The organization responsible for the classification of viruses based on their genetics, chemistry, morphology, and mechanism of replication.

Transduction

The process of transferring genetic material between bacterial cells via bacteriophages.

Genomic material

The nucleic acids (DNA or RNA) that make up the genetic information of a virus.

Persistent Viral Infections

Infections where viruses remain in a host without killing it quickly, often leading to chronic or latent states.

Difference between enveloped viruses and naked viruses

Enveloped viruses have an outer lipid membrane derived from the host cell, which helps them evade the immune system, while naked viruses lack this envelope and are generally more resistant to environmental conditions.

ICD (International Classification of Diseases)

A standardized system used to classify and code diseases, symptoms, and procedures for health management and statistics, aiding in diagnosis, treatment, and the collection of epidemiological data.

Virulent Phages

Phages that exclusively follow the lytic cycle. Steps include: 1. Attachment to the host cell. 2. Injection of phage DNA. 3. Replication of phage components. 4. Assembly of new phage particles. 5. Lysis of the host cell to release the new virions.

Temperate Phages

Phages that can exist in a lysogenic cycle, with the following steps: 1. Attachment to the host cell. 2. Injection of phage DNA. 3. Integration of phage DNA into host genome (prophage state). 4. Replication of host cell with prophage until induction occurs, triggering the switch to the lytic cycle.

Generalized Transduction

DNA is random when transferred during lytic cycle

Specialized Transduction

occurs at the end of lysogenic cycle and can go transfer host DNA

Retrovirus

uses reverse transcriptase enzyme to synthesize cmplementary ssDNA (cDNA) from +ssRNA template (RNA to DNA)

what is bacteriophages and what are it’s steps

Bacteriophages are viruses that specifically infect bacteria, it’s steps include; inoculation (virus causes infection), eclipse (virus with no virions binds and penetrates), burst (virions released from lysed host cell), and burst size (release).

viral detection can be determined by

effects on host cells, hemagglutination assay, nucleic acid test, enzyme immunoassay

Cytopathic effects

cell abnormalities due to viral infections, such as changes in cell shape, shrinkage of nucleus, or loss of adhearence. fusion of cytoplasmic membrane forming multiple nuclei, and cell lysis.

Cytopathic effects of Paramyxovirus

Paramyxovirus can lead to cell fusion, forming syncytia, and cause local inflammation and cell death.

Cytopathic effects of Poxvirus

Poxvirus induces cytoplasmic effects resulting in cell lysis and necrosis, characterized by the formation of lesions.

Cytopathic effects of Herpesvirus

Herpesvirus causes lysis of infected cells, induces the formation of multinucleated giant cells, and can lead to latent infections.

Cytopathic effects of Adenovirus

Adenovirus triggers rounding of cells, cell death, and necrosis primarily in epithelial tissues.

hemagglutination Assay

detection of virus from patien serum, observes clumping (agglunation) of red blood cell, can be done without a microscope, viruses attach to RBC’s via spikes

what are EIAs

Enzyme Immunoassays (EIAs) are laboratory techniques used to detect and quantify proteins, hormones, or antibodies in a sample by using enzyme-linked ImmunoAssay (ELISA) and a substrate that produces a measurable signal.