Microbio (Boards)

5 years from now a new flu virus emerges. Scientists link it to birds, what is most likely to be the cause?

influenza A

prophage

integrated viral DNA

predominant bacteria on mucous memb of oral cavity

lactic acid bacteria + streptococci

Which of the following cell types produce IL-1?

macrophages

Rhinoviruses

main cause of common cold (no vaccine)

Influenza C

mild upper resp tract illness

Antigenic drift

minor changes caused by small genetic mutations (point mutations

negatie polarity (complimentary to mRNA)

must transcribe their own mRNA using negative strand as template

in addition to peptidoglycan, acid-fast cell wall of Mycobacterium contains large amt of glycolipids, esp ______ that make up 60% of acid-fast cell wall

mycolic acids

adenovirus

naked (nonenveloped) icosahedral nucleocapside + ds linear DNA genome

paramyxoviruses

negative sense ssRNA enveloped RNA-dependent RNA polymerase resembles orthomyxoviruses except they are larger, diff surface proteins, nonsegmented genomes

PicoRNAviruses

nonelnveloped ss positive sense RNA genome incapable of causing cell transformation

negative polarity or contain negative-sense RNA

orthomyxoviruses paramyxoviruses rhabdoviruses

bacteriophage w/ ability to form stable, nondisruptive relationship w/in bacetrium

temperate phage vs. virulent phage (lyses & kills host)

infarction causes

thrombosis obstruction from embolus/plaque aneurysm mechanical compression from tumor/hernia vessel rupture

The act of rough pneumococci, grown in the presence of DNA from dead smooth pneumococci, developing capsules is an example of

transformation (Genetic exchange b/w strains of bateria by transfer or incorporation of free DNA from another ruptured bacterial cell)

HSV-1

trigeminal ganglia oral secretions child under 10yo

Human adenoviruses are unlikely to target CNS b/c adenoviruses prefer epithelial cells for replication

true & related

RNA viruses

tx in cytoplasm (except for retroviruses + influenza viruses) tx involve sRNA-dependent RNA polymerase (except retroviruses)

DNA viruses

tx in nucleus (except for poxviruses) tx involves host-cell DNA-dependent RNA polymerase

widespread rash on trunk + face of child. mother states child has received vaccinia vaccine. child most likely infected w/

varicella-zoster virus 90% cases occur in children under 9yo. vesicles in skin -> disseminate ->become encrusted & fall off in 1wk administration of aspirin = CONTRAINDICATED (may increase incidence of REYE syndrome - encephalitis, liver impairment)

herpes virus infection that can be treated prophylatically by vaccine

varicella-zoster virus varicella - chickenpox herpes zoster - shingles attenuated varicella vaccine

DNA enveloped viruses

variola (smallpox) virus Hep B virus Epstein-barr virus NOT adenovirus

High fever (101-102F) that begins suddenly, muscle/bodyaches, chills, tiredness, sudden onset

Influenza

essential to f(x) of outer memb of gram-neg bacteria

LPS

Detection of protein A

Stphylococcus Aureus

T lymphocytes

CMV (cytomegalovirus) congenital infection (if mother becomes infected) infection in immunocompromised

Steps in replicative cycle of viruses

1) Attachment (receptor) 2) Entry (receptor-mediated endocytosis/membrane f(x)) 3) Uncoating (triggered by pH changes in endosomes) 4) Replication + viral protein production -all DNA viruses (except poxviruses) rep in nucleus using host cell RNA polymerase -all RNA viruses (except retroviruses, orthomyxoviruses) replicate in cytoplasm using their own RNA polymerase) 5) Assembly (new virus particles) 6) Release (budding thru host plasma memb or plasma memb ruptuer)

virus

1) Retroviruses contain RNA genome & reverse transcriptase 2) false - provirus = formed as viral RNA is directly incorporated into host DNA

bacteria

1) lancefield groups are based on antigenic characteristics of a cell wall carb called C substance 2)main pathogenic Lancefield groups for humans are A, B, C, D, G Group A (S. pyogenes), Group B (S. agalactiae)

Measles

1) paramyxovirus 2) resp droplets 3) ssRNA

4 characteristic phases of population growth of bacteria

1. Lag phase (cells are metabolically active but not dividing; resynthesis of EZs, coEZs, etc necessary for growth) 2. Log (logarithmic or exponential) phase (fastest growth period) 3. Maximum stationary phase (medium is being depleted in some nutrients) 4. Decline (Death phase)

Retroviruses

2 identical, ss +-sense RNA molecules RNA dependent DNA polymerase (reverse transcriptase)

nucleocapsid of HIV

2 ssRNA, reverse transcriptase, protease, integrase env gene (GP 120, GP41) pol gene gag gene (core proteins)

bacterial virus

Bacteriophage

Type 2

Cytotoxic, IgM or IgG, complement

Type 4

Delayed, CD4 + CD8, CD8 dominates

resting memory B lymphocytes

EB (Epstein Barr virus) primary: infectious mononucleosis secondary: Burkitt's lymphoma, B cell lymphoma, hairy leukoplakia, nasopharyngeal carcinoma

Sympathetic stimulation has an effect on carbohydrate metabolism because

Epi increases liver glycogenolysis

endotoxins = part of outer memb of cell wall of (lipopolysaccharides - LPS) LPS activates complement

Gram negative bacteria only

Staphylococcus aureus

Gram-positive Coagulase positive Causes infective endocarditis Possesses Surface protein A causes toxic shock syndrome hyaluronidase Catalase-positive Scalded skin syndrome

Lentiviruses

HIV 1 (AIDS) HIV 2 (AIDS)

virus

HSV type 2 mainly spreads by sexual contact can be spread from mother to infant during childbirth

trigeminal ganglion

HSV-1 primary: gingivostomatitis secondary: cold sore, keratitis, encephalitis

sacral gangli

HSV-2 genital herpes

Oncovirus

HTLV-1 (adult T-cell leukemia) HTLV-2 (myelopathy)

Influenza viruses = Orthomyxoviruses A + B most common in humans

Hemagglutinin (attachment) Neuraminidase (release) Negative-sense Lipoprotein coat Segmented Genome (Antigenic Shift - reassortment of genome pieces) negative sense ssRNA (Segmented) NOT ssDNA

cell w/in which a virus replicates

Host cell

Type 3

Immune Complex, IgG, complement

integration into host genome w/o killing host

Lysogenic cycle

viral multiplication w/in a host cell leading to destruction

Lytic cycle

Streptococcus pyogenes

M protein hyaluronidase rapidly destroys tissue

skin rash w/ Koplik spots

Measles (Rubeola)

painful swelling of parotid glands

Mumps

influenza C

NOT annual flu ONLY humans least severe ONLY antigenic drift

Inflammation of pharynx

Pharyngitis

virus

Retroviruses = RNA viruses that have genome surrounded by inner protein envelop & outer envelop that contains lipid & glycoprotein spikes, which serve to attach virus to host cells "retro" refers to possession of EZ reverse transcriptase (RNA-directed DNA polymerase), which tx's RNA to DNA during process of viral nucleic acid synthe

Flu-like symptoms & lymphadenopathy followed by rash on entire body

Rubella

crosses placenta TORCH - Toxoplasmosis, Others (syphilis, varicella, mumps, parvovirus, HIV), Rubella, CMV, Herpes Simplex

Rubella Herpes HIV Cytomegalovirus NOT measles

HSV-2

Sacral Ganglia sexual means (genitals)

produces hyaluroniase

Staph aureus Strep pyogenes Clostridium Perfrigens NOT Bordetella pertussis

Which family comprises 2 genera: Rubiviruses (rubella virus) + Alphaviruses (artrhopod-borne viruses)

Togavirus family

transfer of DNA from donor cell to recipient cell w/ DNA packaged w/in bacteriophage

Transduction

dorsal root + cranial nerve ganglia

VZV (varicella-zoster) primary: chickenpox secondary: singles

Antigenic shift

abrupt major change to virus by combining 2/more viruses to create mix of surface antigens

Mycobacterium species, along w/ members of a related genus Nocardia = classified as

acid-fast bacteria

What type of hypersensitivity reaction is mediated by IgE?

anaphylactic

Type 1 hypersensitivity

anaphylactic, IgE, IgG

influenza B

annual flu affects only humans not likely to change or pandemic ONLY antigenic drift

influenza A

annual flu infect animals (birds) + humans antigenic shift & drift -> rapidly changes & creates potential for pandemic

positive polarity (same as mRNA)

can use their RNA genome directly as mRNA

cariogenicity of S. mutans = ability to adhere to tooth surface. Attachment = largely due to presence of extracellular glycocalyx =

capsule protects cells against phagocytosis by eukaryotic cells mediates adherence identification purposes antiphagocytic polysach capsules

Congenital Rubella syndrome

cataracts heart defects deafness

Which of the following maintains a continuous antimicrobial effect (substantivity)?

chlorohexidine gluconate (12hr)

other staphylococci

coagulase negative

Amantadine

drug most commonly used to treat influenza

Herpresviruses

dsDNA nuclear membrane icosahedral nucleocapsid enveloped only viruses to obtain virion envelops by budding from host nuclear or Golgi membrane, not host plasma membrane

vaccinia vaccine

eliminated smallpox

Endotoxin

gram - LPS high potency low specificity not secreted; cell must due & lyse to release

Exotoxin

gram - and + protein extracellular high potency high specificity

members of Picornaviridae

hepaDNAvirus

ludwig's angina

infection of oral cavity infection of 3rd mand molar escapes oral cavity & fills submandibular + submental triangles migrating swelling can compress airway can be fatal w/o dental care

Epstein-barr virus = causative agent for all

infectious mononucleosis nasopharngeal carcinoma Burkitt lymphoma oral hairy leukoplakia

phage T4

infects E.coli

Influenza A

pandemics + epidemics

acid-fast wall components

peptidoglycan (prevents osmotic lysis) mycolic acids (impede entry of chemicals) surface proteins periplasm (contains EZs for nutrient breakdown)

largest & most complex DNA virus family

poxvirus family largest & most complex viruses known

virus

prions = generally quite resistant to proteases, heat, radiation, formalin treatments, altho their infectivity can be reduced by such treatments prion dx's = usually rapidly progressive & always fatal

Which of the following is true of Streptococcus pyogenes?

releases endotoxins (attach to host tissues, evade immune response, spread by penetrating host tissue layers) human pathogen causes strep throat, scarlet fever, impetigo, rheumatic fever, form of glomerulonephritis, mitral valve affected Scarlet fever = antibodies produced to fight S. pyogenes cross rxt w/ host heart tissue group of A beta-hemolytic, gram + streptococcus

paramyxovirus that causes many resp infection epidemics each winter. common cause of bronchiolitis in infants, complicated by pneumonia in approx. 10% of causes

resp syncytial virus (RSV) lacks envelop glycoproteins covered w/ spikes no vaccine or antibiotics available antigenic drift

positive sense RNA/ positive polairity

retroviruses

virus

rotaviruses = most common cause of gastroenteritis in children reoviruses have icosahedral capsid composed of outer + inner protein shell containing double-stranded segmented genome (nonenveloped)

capsules

s. mutans Klebsiella pneumoniae Cryptococcus neoformans

poliovirus (enteroviruses, rhinoviruses, hep A)

salk vaccine (killed-IV) sabin vaccine (live,attenuated-orally) picornaviridiae

Influenza B

smaller/localized outbreaks (camps, schools)

Orthomyxoviruses + Paramyxoviruses share

ssRNA enveloped negative-sense NOT segmented (only orthomyxoviruses)

In which muscular triangle of the neck will you initially find swelling in a Ludwig's angina clinical case?

submental + submandibular triangles

Adenosine arabinoside (vidarabine)

suppresses synthe of varicella-zoster & HSV tends to diminish new lesion formation & duration of fever prevents spread of virus thru viscera

lysogenic bacteirum

temperate bacteriophage