Microbiology: Viruses, CNS, Skin/Reproductive, Respiratory, and Immune System Infections

Comprehensive set of 120 vocabulary flashcards covering virology fundamentals, central nervous system infections, skin and reproductive herpesviruses, respiratory viruses, retroviruses, and immunology concepts from the course lecture notes.

Viruses

Acellular infectious agents lacking a cytoplasmic membrane, cytosol, functional organelles, and independent metabolism that require a host cell to replicate.

Virion

The extracellular, metabolically inactive infectious viral particle that directs the synthesis of viral components only after entering a host cell.

Bacteriophages

Viruses that specifically infect bacterial cells.

Viral Genome

The viral genetic material consisting of either DNA or RNA (never both), which may be single- or double-stranded, linear or circular.

Capsid

The protective protein coat surrounding the nucleic acid genome of a virus.

Nucleocapsid

The macromolecular complex formed by the viral protein capsid together with its enclosed nucleic acid genome.

Viral Envelope

A lipid membrane acquired from host cells by certain viruses, which is relatively vulnerable to environmental disruption.

Glycoprotein Spikes

Viral projections embedded in the lipid envelope that function to recognize and bind specific host-cell receptors.

Enveloped Viruses

Viruses surrounded by a host-derived lipid membrane; examples highlighted in the lecture include herpesviruses and HIV.

Nonenveloped (Naked) Virus

A virus that lacks a host-derived lipid envelope; the primary example identified in the notes is poliovirus.

Helical Capsid Symmetry

A viral structural symmetry in which repeating protein subunits form a spiral tube around the genome; exemplified in notes by tobacco mosaic virus.

Icosahedral Capsid Symmetry

A geometric capsid shell composed of triangular faces; examples in notes include poliovirus, rhinovirus, and adenovirus.

Complex Capsid Symmetry

A mixed or specialized viral architecture featuring additional components; exemplified by bacteriophage diagrams showing a head, tail, and attachment structures.

DNA Virus Replication

Viral replication that typically takes place in the host cell nucleus using DNA polymerases, after which viral mRNA is produced for host ribosomes to translate.

RNA Virus Replication

Viral replication that frequently occurs in the host cell cytoplasm, utilizing viral RNA polymerases to copy the genome.

Viral RNA Polymerase

An enzyme responsible for copying viral RNA genomes that is error-prone, causing RNA viruses to accumulate mutations rapidly and facilitate immune escape.

Viral Binding (Attachment)

The initial step of the viral life cycle where viral surface proteins or glycoprotein spikes engage specific receptors on the surface of a host cell.

Viral Uncoating

The life cycle step following viral entry and fusion wherein the viral capsid is degraded or removed to release the viral genome into the host cell.

Viral Assembly

The stage of the viral replication cycle where newly synthesized viral genomes and viral proteins are packaged into new virions.

Budding

A viral release mechanism in which an enveloped virus exits through a host membrane, acquiring its lipid envelope in the process.

Lysis

A viral release process in which the host cell breaks open, releasing progeny virions into the extracellular space.

Exocytosis

A cellular release pathway depicted in the lecture diagrams utilized by certain viruses to exit an infected host cell.

Antiviral Drug Targets

Specific points of viral replication targeted by therapeutics: attachment, fusion, uncoating, polymerases, reverse transcriptase, protease/maturation, and release.

Direct Viral Injury

Cellular and tissue damage caused directly by viruses via damaging host cells, disrupting host synthesis, or driving abnormal cell growth.

Immune-Mediated Damage

Tissue injury and clinical disease symptoms provoked by the host's own immune response reacting against a viral infection.

Meningitis

Inflammation of the meninges, especially affecting the leptomeninges.

Encephalitis

Inflammation involving the brain tissue itself (brain parenchyma).

Meningoencephalitis

An inflammatory condition involving both the meninges and brain tissue simultaneously.

Subarachnoid Space

The anatomical space that contains cerebrospinal fluid (CSF) to cushion the brain and spinal cord.

Total CSF Volume

The total volume of cerebrospinal fluid in the central nervous system, given as approximately $150\,\text{mL}$.

Daily CSF Production

The baseline physiological rate of cerebrospinal fluid formation, stated as about $500\,\text{mL}$ produced daily.

CSF Opening Pressure

The hydrostatic pressure measured during a lumbar puncture, normally falling below $200\,\text{mm H}_2\text{O}$.

Normal CSF Protein

The baseline protein concentration specified in the prework outline as $15\text{--}50\,\text{mg}$.

Normal CSF Glucose

The baseline glucose level specified in the prework outline as $45\text{--}100\,\text{mg}$.

Blood–Brain Barrier

A regulatory physiological boundary that controls exchange between the bloodstream and the central nervous system, affecting pathogen access.

CSF Pleocytosis

An elevated white blood cell count in the cerebrospinal fluid, defined in the outline as more than five white blood cells.

Nuchal Rigidity

Neck stiffness or resistance to passive neck flexion, representing a classic physical finding in meningitis.

Photophobia

Abnormal sensitivity and discomfort to light, frequently identified in patients with meningitis.

Phonophobia

Abnormal sensitivity and discomfort to sound, documented as a common clinical finding in meningitis.

Kernig Sign

A clinical test for meningeal irritation characterized by pain or resistance with knee extension while the hip is flexed.

Brudzinski Sign

A physical exam sign of meningeal irritation wherein passive neck flexion provokes involuntary hip and knee flexion.

Lumbar Puncture

A diagnostic procedure used to sample CSF to assess opening pressure, cell counts, differential, protein, glucose, and pathogen testing.

Polymerase Chain Reaction (PCR)

A molecular diagnostic technique that amplifies specific nucleic-acid targets using primers, a template, nucleotides, and reaction components.

Bacterial Meningitis CSF Profile

A cerebrospinal fluid presentation typically featuring neutrophil predominance, markedly elevated protein, reduced glucose, and often high opening pressure.

Viral Meningitis CSF Profile

A cerebrospinal fluid presentation typically featuring lymphocyte predominance, normal to moderately elevated protein, relatively preserved glucose, and normal or elevated pressure.

Leptomeninges

The innermost meningeal membranes primarily inflamed during an episode of meningitis.

Bacterial Meningitis Urgency

A medical emergency requiring prompt diagnostic evaluation and urgent antibacterial therapy.

Neutrophil Predominance

A high white blood cell differential pattern in cerebrospinal fluid that typically indicates bacterial meningitis.

Lymphocyte Predominance

A white blood cell differential pattern in cerebrospinal fluid that characteristically points to viral meningitis.

Encephalitis Clinical Clues

Neurological findings including altered mental status, confusion, personality change, sluggishness, agitation, fatigue, and seizures.

HHV-1 (HSV-1)

Human herpesvirus 1, an alpha herpesvirus commonly associated with oral herpes and cold sores, though capable of causing genital infection.

HHV-2 (HSV-2)

Human herpesvirus 2, an alpha herpesvirus commonly associated with genital herpes, though capable of causing oral infection.

HHV-3 (Varicella-Zoster Virus)

Human herpesvirus 3, an alpha herpesvirus that causes chickenpox during primary infection and shingles upon reactivation.

Alpha Herpesviruses

A herpesvirus subfamily characterized in lecture slides by establishing latency within sensory neurons.

Beta Herpesviruses

A herpesvirus subfamily characterized in lecture slides by establishing latency within white blood cells.

Gamma Herpesviruses

A herpesvirus subfamily characterized in lecture slides by establishing latency within lymphocytes.

Herpesvirus Latency

The biological state in which viral genetic material persists inside host cells without the continuous production of symptomatic lesions.

Trigeminal Ganglia

The sensory nerve ganglia in which HSV-1 establishes latent viral infection.

Sacral Ganglia

The sensory nerve ganglia in which HSV-2 establishes latent viral infection.

Herpes Prodrome

Early warning sensory symptoms, such as tingling or burning sensations at the site of infection, occurring before visible vesicles erupt.

Asymptomatic Viral Shedding

The transmission of infectious virus via saliva or genital secretions in an individual who lacks visible lesions or active symptoms.

Herpes Labialis

Recurrent herpes simplex virus lesions or cold sores that classically erupt near the lip border.

Herpetic Whitlow

A localized herpes simplex virus infection affecting a finger.

Herpes Gladiatorum

A cutaneous herpes simplex virus infection associated with close-contact sports.

Eczema Herpeticum

A serious, widespread cutaneous herpes simplex virus infection occurring in individuals with compromised or disrupted skin.

Herpetic Keratoconjunctivitis

An ocular herpes simplex virus infection presenting with pain, redness, tearing, light sensitivity, blurred vision, and branching corneal lesions.

Neonatal Herpes

A potentially severe and life-threatening herpes simplex virus infection occurring in newborns.

Chickenpox

The primary clinical manifestation of varicella-zoster virus infection, characterized by a widespread, itchy vesicular rash.

Shingles (Herpes Zoster)

The clinical condition resulting from the reactivation of latent varicella-zoster virus, producing painful, localized dermatomal vesicles.

VZV Incubation Period

The time period from exposure to the onset of varicella-zoster virus symptoms, noted as approximately two weeks.

Varivax

A live-attenuated childhood vaccine used to protect against primary varicella-zoster virus infection (chickenpox).

Shingrix

A two-dose recombinant subunit vaccine indicated for eligible older or immunocompromised adults to prevent shingles.

Acyclovir

A guanosine analogue antiviral whose triphosphate form inhibits viral DNA polymerase and terminates viral DNA chain elongation.

Acyclovir Activation Sequence

The intracellular three-step enzymatic activation pathway: acyclovir $\rightarrow$ monophosphate $\rightarrow$ diphosphate $\rightarrow$ triphosphate.

Prodrug

A medication administered in an inactive or less active form that is subsequently converted by the body into an active drug.

Bioavailability

The proportion of an administered drug dose that successfully enters systemic circulation to exert its therapeutic effect.

Valacyclovir

An oral antiviral prodrug form of acyclovir cited in the outline for treating herpesvirus infections.

Famciclovir

An antiviral guanosine analogue appearing on the treatment slides used to manage herpesvirus infections.

Upper Respiratory Tract

The anatomical portion of the respiratory system that includes the nose, nasopharynx, pharynx, and larynx.

Lower Respiratory Tract

The anatomical portion of the respiratory system that includes the trachea, bronchi, bronchioles, and lungs.

Rhinovirus

A respiratory virus associated in lecture with rhinitis, laryngitis, and the common cold.

Rhinitis

Inflammation of the nasal cavity and nasopharynx, classically linked to rhinovirus.

Pharyngitis

Inflammation of the pharynx, caused by influenza and multiple other respiratory viruses.

Laryngitis

Inflammation of the larynx, listed with viral causes including rhinovirus.

Croup

An upper airway and tracheal infection classically associated with a barking cough and parainfluenza virus.

Parainfluenza Virus

A respiratory pathogen highlighted in the course as the classic causative agent of croup.

Bronchitis

Inflammation involving the bronchial airways, associated with multiple respiratory viruses.

Viral Pneumonia

An infection of lung tissue that can be caused by influenza and other respiratory viral pathogens.

Influenza A

An influenza type that infects humans and animal species, possesses a segmented RNA genome, and undergoes both antigenic drift and shift.

Influenza B

An influenza type that primarily circulates in humans, causes seasonal epidemics, and predominantly undergoes antigenic drift rather than major shift.

Influenza C

An influenza type that generally causes mild illness and is not a typical cause of major seasonal epidemics.

Hemagglutinin (H)

An influenza surface glycoprotein that mediates viral binding to host-cell sialic-acid receptors.

Neuraminidase (N)

An influenza surface enzyme that facilitates the release of newly formed virions from the host cell.

M2 Ion Channel

A protein channel found in influenza A that is involved in the uncoating process during viral entry.

Segmented RNA Genome

The fragmented genome structure of influenza A that enables genetic reassortment when different strains coinfect a single host cell.

Antigenic Drift

Gradual, smaller changes in viral surface antigens arising from accumulated mutations during error-prone viral RNA replication.

Antigenic Shift

Abrupt, larger changes in viral antigens resulting from genome segment reassortment, seen in influenza A and creating pandemic risk.

Zoonosis

An infectious disease that passes between animals and humans, acting as a reservoir for emerging viral pathogens.

Influenza Period of Infectiousness

The transmission window beginning approximately one day before symptoms appear and extending roughly five to seven days after illness onset.

High-Risk Influenza Groups

Populations identified in the outline as being at higher risk of complications, including young children, older adults, pregnant patients, and those with chronic cardiopulmonary illness.