Random Comprehensive RNA Viruses-Fungi Flashcards
1
Q
Streptococcus Pneumoniae (pneumococcus)
A
- Gram(+) cocci
- pneumonia, sinusitis, otitis media, meningitis
- normal flora in oropharynx (opportunist)
- infection follows cold or influenza
- insults such as smoking and alcohol
- capsule blocks opsonization by complement C3b (inhibits macrophages, antibody needed to kill) -Self limiting, Not severe
1
Q
Creutzfeldt-Jakob Disease
A
- sporadic, familial, iatrogenic (from pituitary of cadaveric victims)
- neurodegenerative -myoclonus, behavioral changes, dementia
- New Variant (vCJD): associated with mad cow
- genetic susceptibility (met-met at codon 129 of gene PRNP -fatal (no cure)
2
Q
Herpes Simplex Virus 1 and 2
A
- HSV1: oral secretions
- HSV2: genital secretions
- painful ulcerating lesions on skin or mucous membranes
- Herpes encephalitis and hepatitis (rare HSV1)
- neonatal Herpes–serious complication of maternal genital herpes (high mortality)
- acyclovir effective
3
Q
Human Parvovirus B19
A
- Epidemiology: spreads person to person by respiratory route. Infection common and occurs in outbreaks, mostly among children.
- Pathology: gains entry to erythroid precursor cells via P erythrocyte antigen and produces certain cytopathic effects: enlarged nuclei with peripheral chromatin displacement and eosinophilic material nuclear inclusion bodies.
- Clinical Features: Mild exanthematous illness (rash) known as erythema infectiosum, accompanied by interruption of erythropoiesis (mostly asymptomatic). Potentially fatal anemia caused in hosts with chronic hemolytic anemia–transient aplastic crisis. Fetal infection leads to severe anemia, hydrops fetalis, and death in utero (10% of maternal infections).
4
Q
Tuberculosis (Mycobacterium tuberculosis hominis, M. bovis)
A
- Spreads by aerosols from person to person, enters into the lungs
- Forms GHON COMPLEX lesions in lungs (area of infection + lymph nodes) - contains caseous granuloma (necrotizing center) / hilar lymphadenopathy,
- Most cases of primary TB are asymptomatic. In progressive cases (kids, immunocompromised, homeless) non specific symptoms (fever, night sweats, weight loss, fatigue).
- Secondary TB (reactivation or reinfection) - T-cells are already familiar with antigen and cause necrosis and cavities in lungs. Same as primary symptoms + hemoptysis. Disease may disseminate (miliary) and become fatal.
- Todays treatment - long term antibiotics.
4
Q
Glanders
A
- Rare, granulomatous disease.
- Zoonotic; associated with horses.
- Burkholderia mallei aka pseudomonas mallei
- Transmission via cuts in the skin, via musoca, or inspiration.
- invade macrophages-acute granulomatous infection
- Nodular lesions in the lungs and ulceration of the mucous membranes in the upper respiratory tract.
- lymphadenitis + splenomegaly
- Acute bacteremia => Almost always fatal. Generally a 50% mortality rate and very small minimum infectious dose.
5
Q
Rocky Mountain Spotted Fever
A
- Tick-borne, caused by Rickettsia rickettsii , Gram (-) coccobaccilus.
- obligate intracellular pathogen
- Serious, life-threatening illness.
- Early presentation is non-specific, febrile.
- 2-5 days after fever
- Maculopapular or petechial rash spreading from limbs toward trunk.: from infection of vascular smooth muscle and endothelium of large and small vessels
- microthrombi–infarction + dic from hemorrhaging of blood vessels–fatalities
- other symptoms: pulmonary edema,
5
Q
Psittacosis (Ornithosis) (Chlamydiae psittaci)
A
- Spread from Birds in tropics–zoonotic.
- inhalation–atypical pneumonia: no lobar infiltrates
- obligate intracellular pathogen–alveolar cells + macrophages
- Self-limited interstitial pneumonia–alveolar cell lining necrosis and invasion of macrophages
- disseminates–necrosis in liver and spleen and mononuclear infiltrates (macrophages) in heart, kidney and brain. Rose colored spots appear: Horder’s spots
- splenomegaly
- death from complications from hepatitis, endocarditis, myocarditis, encephalitis (
5
Q
Pinta (Treponema carateum)
A
- spirochete, invade macrophages
- Skin-to-skin transmission
- Mexico, Central America
- Colored spots, scaly/flakey, disease limited to the skin; may leave behind areas of hyperpigmentation
6
Q
Actinomyces (Actinomycosis)
A
- filamentous, anaerobic, Gram(+) commensual saprophytes present in oropharynx, GI tract, vagina–requires trauma to cause disease (anaerobic environment)
- Cervicofacial: jaw injury or after dental surgery–leads to purulent abscesses in jaw. “lumpy jaw” -form sulfur granules made of Splendore-Hoeppli material (tangled masses of branching filaments in polysaccharide protein matrix)
- Sinus tracts that penetrate lobe to lobe in pulmonary infections
- progressive, slow growing (anaerobic), disease that is well controlled by antibiotics
- Fatal if untreated
6
Q
Tularemia (Francisella tularensis)
A
- reservoir in rabbits and rodents infection from contact; vector is ticks, deerflies, and mosquitoes.
- metastatic infection–survives within macrophages (granulomatous reaction)
- Acute febrile disease, lymphatic distribution.
- Distribute to major organs via lymph => enlarge, hard nodes => granulomas (necrotizing, described as ‘palisading’)
- Ulceroglandular: pustular lesions (necrosis) with lymphadenopathy and acute febrile illness–significant mortality if untreated
- Occuloglandular = Spread from eye to parotid gland
- Pneumonic-mimic TB with granuloma
6
Q
Human Papillomavirus
A
- person to person contact (STD) -genital warts + cervical cancer (common manifestations)
- depressed cell-mediated immunity with spread of HPV lesions
- koilocytosis: large squamous cells with shrunken nuclei in large cytoplasmic vacuoles.
8
Q
Endemic (Murine) Typhus
A
- Caused by Rickettsia Typhi
- Transmitted by flea; rodent pool.
- Similar phenotype to epidemic louse-bourne typhus, but less dangerous.
-Flea feces can be inhaled–pulmonary infection
9
Q
Cholera (Vibrio cholerae)
A
- aerobic, curved, gram(-) rod
- spread from ingesting contaminated food/water; shellfish are natural reservoir–sporadic outbreaks
- epidemics in areas where human feces pollute water supply -cholera exotoxin: binds GM1 ganglioside in enterocyte cell membrane to enter cell and activated adenylyl cylase- increase cAMP and increase Na+/H20 secretion into intestinal lumen. -severe watery diarrhea with flecked mucus (rice water stools)–leads to fluid and electrolyte loss that leads to shock
- 50% mortality rate in untreated patients (lacking electrolyte and oral rehydration therapy +antibiotis)
- vaccine available (50% effectiveness)
10
Q
Gerstmann-Straussler-Scheinker Syndrome
A
- rare transmissable spongiform encepalopathy
- Cerebellar degeneration–big identifier
- dementia common feature
- some rare sporadic cases, usually familial
12
Q
Blastomycosis (Blastomyces dermatitidis)
A
- Very similar to coccidiomycosis, granulomatous, but also suppurative pulmonary dissease–cavitary pneumonia and meningitis with cerebral abscesses.
- Endemic to Midwest, Mississippi river and Ohio river basins, and around the Great Lakes.
- Skin (>50%) and bones (>10%) are most common sites of extrapulmonary involvement.
- skin lesions from disseminated infection resembling squamous cell carcinoma.
- Usually self-limited (1/3 of patients)
13
Q
Chlamydiae trachomatis Infections
A
- most common STD
- Intracellular, cant make ATP -Elementary body attached to cell and becomes endocytosed
- Reticulate body becomes active inside cell, pirates the cell machinery.
- Genital and Neonatal Infections
- Serovars D through K -Asymptomatic in approx 60% women.
- Inflammation of GU tracts, exudate, PID
- Generally non lethal, can cause permanent damage to reproductive system.
- Lymphogranuloma Venereum
- Serovars 1 through 3
- Buboes or abscesses in the groin (inguinal) region where draining lymph nodes are located, progress to necrotizing lymphadenitis.
- Often seen with HIV.
- Trachoma
- Serovars A,B,C
- Leading cause of blindness in underdeveloped.
- Neonatal exposure from mom.
- Effects eyes: characteristic roughening of the inner surface of the eyelids. -Painful, Can lead to visual impairmnent.
14
Q
Sporotrichosis
A
- Rose Gardner’s disease
- accidental inoculation through breaks in skin from thorns piercing skin.
- chronic granulomatous skin infection with suppurative center-necrosis and ulceration–lead to secondary cellulitis
- can disseminate through lymphatic vessels-spread to joints and bone.
15
Q
Epstein-Barr Virus
A
- infectious mononucleosis: fever, malaise, pharyngitis, splenomegaly
- lymphadenopathy–spleen and lymph nodes (cervical)
- atypical lymphocytes
- heterophilic antibody–distinguishing lab test
16
Q
Anthrax (Bacillus anthracis)
A
- Gram-positive, endospore-forming, rod-shaped bacterium
- spore form in dead animals/soil and reservoir in goats/sheep/cattle/dogs/pigs/horses
- spread through inhalation, breaks in skin, ingestion with germination in body
- Malignant pustule: Cutaneous form (most common) papule/ulcer–lymphadenitis can lead to septicemia. (without dissemination–self-limited no complications)
- Pulmonary: “woolsorter’s disease” respiratory failure and shock within 24-48 hours.
- Septicemic: DIC, exotoxin depresses respiratory center–antibiotics ineffective against exotoxin
- Gastrointestinal: rare, eating contaminated meat: stomach + bowel ulceration–death caused by fulminant diarrhea and massive ascites
16
Q
Botulism (Clostridium Botulinum)
A
- neurotoxin present in improperly canned food (blocks acetylcholine release): Don’t feed newborns honey
- descending paralysis, blurred vision
- untreated: lethal
- antitoxin- 25% mortality
17
Q
Lyme disease (Borrelia burgdorferi)
A
- Zoonotic spirochete, Transmitted by ticks, reservoir = mice, deer.
- Stage 1: erythema chronicum migrans (characteristic annular red lesions), fever, malaise
- Stage 2: muscle, heart, and nerve problems, including meningitis and facial nerve palsy
- Stage 3: more joint, skin, and nerve problems - mimics rheumatoid arthritis
- Late manifestations (years later): acrodermatits chronica atrophicans, patchy atrophy and sclerosis of skin
- Diagnosis usually established using antibody titers
17
Q
Tropical Phagedenic Ulcer (Bacillus fusiformis and Treponema vincentii)
A
- a.k.a Tropical Foot, fusospirochetal infection
- Follows trauma (lesions) in the tropics, malnutrition is a factor.
- Painful leg legion with necrosis, sloughing of skin, and gray putrid exudate -May be complicated by tibial osteomyelitis and squamous cell carcinoma
- Deep wounds that persist for years, often need reconstructive surgery to fix
18
Q
Haemophilus influenzae
A
- aerobic, pleomorphic, gram(-) coccobacillus, nonencapsulated, capsulated(Type B): most virulent
- P2P spread: respiratory droplets and secretions
- Normal flora of oropharynx -pyogenic infection, MENINGITIS (#1 cause in
- broncopneumonia, epiglottitis (obstruct airway), septic arthritis (bacteremic), facial cellulitis (bacteremic)
- vaccine: nearly eliminated infantile meningitis
19
Q
Escherichia coli
A
- antigenically diverse, aerobic (facultatively anaerobic), gram(-) rod, most commensal and opportunistic
- synthesize vitamin K2, virulence after plasmid transfer
- 90% of all urinary tract infections -bladder mucosa infection–dysuria, pyuria (leukocytes in urine)
- Immunocompromised: Pneumonai, sepsis
- neonatal meningitis: colonizes vaginal canal
- Four strains:
- ENTEROTOXIGENIC: traveler’s diarrhea from contaminated water and food, self-limited (Africa, Latin America)–produce 3 enterotoxins–secretory dysfunction of small bowel (one similar to cholera-adenylyl cyclase, other acts on guanylyl cyclase)
- ENTEROPATHOGENIC: diarrheal illness in tropical regions among infants and children, spread from contaminated food and water, deforms microvilli of intestinal epithelial cells, fever + malaise
- ENTEROHEMORRHAGIC: bloody diarrhea, fever, cramping abdominal pain, hemolytic-uremic syndrome (anemia, acute kidney failure, thrombocytopenia), contaminated meat/milk, enterotoxin similar to Shigatoxin
- ENTEROINVASIVE: food-borne DYSENTERY, indistinguishable from shigella (similar toxin to shiga toxin)-self-limited, invades and destroys mucosal cells of ileum and colon. abdominal pain, fever, tenesmus (feeling of incomplete defecation), bloody diarrhea. week long illness
20
Q
A
20
Q
Noma / gangrenous stomatits / cancrum oris
A
- A disfiguring, smelly facial necrosis that destroys both soft tissue and bones of mouth and face
- Often targets malnourished kids in and immune compromised in the tropics
- Common bacteria: T. vincentii, B. fusiformis (fusospirochetal), Bacteroides, Corynebacterium
- Underlying bone may be revealed.
- Usually need antibiotics and reconstructive surgery
20
Q
Listeriosis (Listeria monocytogenes)
A
- reservoir: many species of mammals and birds–rare spread from animal to human
- spread: unpasteurized milk and dairy products
- evades intracellular + extracellular host responses: acidic phagosome activate listeriolysin O exotoxin–escape into cytoplasm and usurps cytoskeleton to form portrusions to dock with other cells (spread without staying in extracellular environmentz)
- Pregancy listeriosis: lead to abortion or premature delivery
- Septicemic listeriorsis: severe febrile illness in immunocompromised–shock and DIC: death without treatment (heavy duty antibiotic course needed)
- Self-limited in healthy host
21
Q
Cat-Scratch Disease (Bartonella henselae)
A
- proteobacteria
- spread from cat scratches inoculated skin or contact with eye.
- papule at site of infection
- invades macrophages–granulomatous–lymphadenopathy
- swollen lymph nodes persist for months
- Parinaud oculoglandular (granulomatous conjunctivitis with swollen facial lymph nodes) syndrome secondary to conjunctival infection
21
Q
Legionella pneumophilia
A
- small, aerobic bacillus, gram(-)
- respiratory spread: aerosols of infected sources, NOT CONTAGIOUS
- pneumoina: Legionaire’s Disease (life-threatening) and Pontiac fever (milder, self-limiting)
- proliferate inside resident macrophages (granulomatous)–macrophages show eccentric nuclei pushed aside by vacuoles containing L. pneumophila
- alveolar necrosis, bronchopneumonia fever, nonproductive cough followed by hypoxia leading to death.
- Silver grain stain, Urine antigen test for diagnosis
21
Q
Cytomegalovirus
A
- infects lymphocytes and monocytes–Infectious Mononucleosis
- symptomatic in immune suppressed patients (as is EBV)
- encephalitis, pneumonitis, GI hemmorhage
22
Q
Nocardia (Nocardiosis)
A
- respiration or cutaneous inoculation
- gram(+) aerobic filamentous
- May affect lungs, brain, skin or systemic dissemination in immunocompromised
- Disease of immunocompromised.
- Pyogenic: Pulmonary abcesses-pyogenic pneumonia w/ central necrosis.
- Fatal if untreated, long term antibiotics.
23
Q
Paracoccidioidomycosis (South American/Brazilian Blastomycosis)
A
- similar to coccidiodomycosis + blastomycosis
- chronic granulomatous infection (with purulent exudates) starting with lung involvement–dissemination in immunocompromised to skin, oropharynx, adrenals, and macrophages of lymphatic system.
- central + south america
- usually acute, self-limited and mild disease
24
Q
Staphylococcus Aureus (coagulase positive)
A
- natural flora on skin–innoculation following injury
- leading cause of infective endocarditis -furuncles, carbuncles, scalded skin syndrome (desquamantion), osteomyelitis, bacterial arthritis
- Septicemia, TSS, food posioning,
- MRSA-antibiotic resistance plus virulence factors (toxins + proteolytic enzymes) encoded on plasmids.
25
Q
Salmonella typhi
A
- P2P spread (chronic carriers commonly old women with gallstones or biliary scarring), and contaminated water/food–dairy and shellfish, oral-fecal route rarer
- granulomatous infection: proliferation inside infected macrophages
- Typhoid fever (SEVERE): degeneration of intestinal epithelium brush border (Peyer patch hypertrophy as well)–capillary thrombosis with ulcerated bowel tissue leading to infectious peritonitis; Systemic dissemination: focal granulomas in liver, spleen (typhoid nodules-macrophages with ingested bacteria,erythrocytes, dead lymphocytes)
- 10-14 day incubation period
- Signs: Bacteremia/invasion: daily increase in temperature (IL-1 + TNF), malaise, arthralgias, abdominal pain–Fastigium: fever/malaise increase–septicemia from release of endotoxin from dead bacteria and hepatomegaly and splenomegaly. Fever abates over weeks to months -10-20% mortality in untreated patients (complications including pneumonia)
- Typhoid antitoxin curative if given within 3 days of fever onset.
26
Q
Neisseria meningitides (Meningococcus)
A
- paired, bean-shaped, gram(-) cocci
- commensual nasopharynx (5-15% population)
- epidemic in crowded areas (military barracks)
- P2P spread: respiratory droplets
- confined to CNS or disseminated
- fulminant fever, stiff neck, headache
- meningococcal sepsis: fever, shock, mucocutaneous hemmorhages, diffuse vascular endothelium damage, petechiae, purpura
- Rare: vasculitis, thrombosis–Waterhous-Friderichsen Syndrome (adrenal hemorrhagic necrosis)
26
Q
Kuru
A
- prototypical prion disease
- neurodegenerative
- transmitted via ingestion (cannibalism of flesh)
27
Q
Clostridium Perfringens
A
- obligate anaerobe, spore forming, gram(+)
- bacterial benign, diarrheal food poisoning
- rare: necrotizing enteritis (enterotoxins-ulcerating ß-toxin)–necrosis: fatal
- GAS GANGRENE: myotoxin–alpha toxin (alpha lecithinase–phospholipase) that destroys cell membranes leading to severe hemolysis and muscle necrosis–SEVERE
28
Q
Chancroid (Haemophilus ducreyi)
A
- gram(-) bacillus, histology looks like school of fish
- P2P: sexually
- Chancroid: leading cause of genital ulcers in 3rd world countries (facilitate spread of HIV)
- opportunistic: enters through breaks in skin
- painful, unilateral, suppurative, inguinal lymphadenitis (bubo)
- erythromycin: effective treatment
