Medical Microbiology 4 Flashcards

Terms Definitions
Rhinovirus Treatment
decongestant
antiviral
hand washing
Rhinoirus
picornavirus
over 100 serotypes
+ sense RNA
naked, likes it 33 degrees C
LOS
LPS without O antigen
Virbrio infections
sepsis
outer ear infection
gastroenteritis
wount infections 
Mycoplasma, legionella, chlamydia, coxiella are all treated with
Erythromycin
Cytokines
chemical messengers produces by leukocytes to send signals & bring in reinforcement
Zoonoses=
infectious disease transmissible under normal conditions from animals to humans
Etiology of Diarrhea
Bacteria:
Salmonella spp. (GNR)
Shigella spp. (GNR)
Campylobacter spp. (GNR
Escherichia coli (GNR)
Clostridium difficile - in hospitalized patients
Protozoa
Giardia lamblia
Cryptosporidium
Viruses
Rotavirus
Norovirus
Inside Virus DNA/RNA
nucleic acid
protein matrix
glycoproteins 
how does staph aureus bind?
fibronectin
Examples of intestinal protozoan infections
giardiasis
cryptosporidiosis
dientamoeba infection
blastocystis infection
amebiasis
Neisseria
enriched, selective agar w/ increased CO2 & humidity
Virulence factors
extracellular proteins help establish & maintain disease; enzymes aid colonization & growth; fibrin clots allow pathogens to live in body and not get attacked; have to be effective because of energy cost or will be cut lose
Vector Transmission=
Animate intermediary in indirect transmission of agent which carries agent from reservoir to host.
Actinomyces spp
strict anaerobe
gram + rod (non-sporeforming)
Group C, G, and F Strep
Cellulites
Endocarditis
Sinusitis
Abscess
Bacteremia
Pharyngitis 
Shigella's physical characteristics:
Gram negative rod
nonmotile
no lactose fermentation
epidemiology of hydatid cyst
China
Africa
Southern hemisphere
although worldwide
Rhinovirus Pathogenesis
upper to lower respiratory
binds to ICAM1
immunity is serotype specific
 
Normal flora
necessary to keep pathogens or competing bacteria away; intimately intertwined in physiology; w/o it, we wouldn't last a week
Molecular route
detect genetics, molecules or Ag's specific to that bug; can also do Ag-Ab test (PCR most common); amplification of nucleic acids
Specific mechanism
prior infection, body already built-up immune response for specific pathogen to be turned on (needs priming from repeated exposure to be more efficient) (secondary immune response)
Agent=
factor whose presence (too much, too little) or absence is essential to occurrence of disease.Can be living or non living
Taenia clinical signs
>Sx: indigestion, diarrhea, see segments>Dx: passing segments or eggsT.solium cyst stage can see scolex>Tx: cook meat, take Rx, meat inspection
Streptococci classification scheme
Beta (complete)Group A: pyogenesGroup B: agalactiaeAlpha (partial)PneumoniaeViridansGamma (Non)EnterococcusViridans
Bacterial DNA
Single circle of double stranded DNA
Complications in men due to Chlamydia
Reiter's Syndrome
Epididymitis 
Etiology of staphylococcus saprophyticus:
Gram positive staphylococci
 
Found primarily in sexually active females
is acute RF still a clinical challenge?
yes
histopath of neurocysticercosis
space ocupying lesions
as cysticerus dies, it elicits infammatory response
inflammatory response sets of seizures
Name six important members of the enterobacteriacea.
Shigella
Salmonella
Escherichia
Klebsiella
Proteus
Yersinia
 
(Mnemonic: SEKSY P. Mmm, that is one sexy pea that I'll eat and send to my GI tract.)
 
(Syllabus: 21-5)
Describe Giardia Lamblia structure
>endoplasmic reticulum and two separate nuclei, no mitochondria, sucking disk.>represents transitional state in eukaryotic evolution
Influenza A & B
genome: 8 - strand, segmented
enveloped
spikes: hemagglutin & neuraminidase (H&N)
attachtment: through H
replicate in the nucleus
Treatment of the Flu
amantadine & rimantadine
zanamivir & oseltamivir
vaccine
Nonspecific mechanism
always turned on, no prior stimulus from particular pathogen; can react towards anything (primary immune response)
Chlamydia
very hard to culture; cell culture & Ag detection or nucleic acid sequencing tests (can also determine if other infections)***for sexually abused - cannot run nucleic test bcz false (+); only cell culture for legal purposes
Vertical Transmission=
from mother to newborn either by pregnancy, childbirth, or breastfeeding
Toxocara canisToxocara catiInfectivity/life cyclePathogenicityPopulation
>Infectivity: Ascarid worm makes egg into poop, eat poop, live in gut. Humans come into contact (fecal-oral) with dog poo>Patho: larva migrates around looking for dog gut. Can get into eye (occular larva migrans) or make tracts along skin (cutaneous larva migrans) making a tract. Respiratory signs, fever, hepatomegaly>Population: kids, Hx pica, SES
Moraxella Catarrhalis

1. Gram stain
2. Causes which diseases?
1. Gram -
2. acute bronchitis
Virulence Factors of Mycobacteria
Waxes in cell wall
cord factor 
penicillin resistant cases of gonorrhea are treated with...
ceftriaxone IM single dose
 
Orally: cefixime, ciprofloxacin, or ofloxacin
Describe the characteristics of Klebsiella Pneumoniae
Gram negative enteric
 
Rod shaped
 
Ferments Lactose
 
Facultatively anaerobic
 
Highly mucoid colonies
dx of candidiasis
culture
germ tube tests (inoculate in 50% serum and germ tube forms if C. albicans)- yeasts form hyphal outgrowth during 2-3 hrs of incubation in serum at 37 C
biopsy for histopath
investigational assays
D arabinotol
enolase
beta glucan
PCR
tx neurocysticerosis
depends on if the cyst is "dead"
single ring enhancing lesion may resolve spontaneously (cysticerusis already dying)
give azole or praziquantel for multiple cysts or cysts without ring enhancement
steroids during larvicial therapy
Contrast pili from nonfrimbrial adhesions.
Pili: Long-rangeNonfimbrial adhesions: Short-range21-2
Describe pathogenesis of E.histolytica
>can move beyond colonic epithelium and invade submucosa to cause ulcers or perforate the colon. Can also get to liver to make abscesses or reach brain.
Stages of Viral Replication (3)
1. attachment and entry
2. synthesis
3. assembly and release
Physical & Chemical defenses
these are independent of immune system; secretions, blood, cilia, mucous, normal flora, skin, acidity, flushing, pH
Locus=
site on or in the body where infection originates
Cryptococcus neoformans1. Geographic location2. Where does it live?3. How does it get into the host?4. Virulence factors5. Presentation6. Diagnosis7. Therapy
1. Ubiquitous2. Soil, bird droppings, trees, rotted wood3. Inhaled4. Polysaccharide capsule - antiphagocytic, antidetection, source of the cryptococcus antigen. Melanin - protects it against radical oxygen species. It grows best at 37 degrees C.5. Most common and seriously is cryptococcal meningitis - usually a subacute meningitis (headache, vague neurological complaints, +/- fever). Also can cause pneumonia, cryptococcemia, skin lesions, prostatitis6. India ink stain of CSF, culture of CSF, or detection of cryptococcus antigen in blood or CSF7. Amphotericin + flucytozine, followed by fluconazole for maintenance
Borrelia Burgdorferi1. Characteristics2. Reservoir/Transmission/Location3. Pathenogenesis/Course of Disease4. Diagnosis and Treatment
1. Spirochete2. Ticks. Tick bite must be 48 hrs. Coastal areas of southern NE and New York, Midwest (Wisconsin, Minnesota, Michigan), Coastal woodlands of Calif and Oregon3. Osps = surface lipoproteins: tropism and tissue attachmentInvades skin and widely disseminates, getting into the blood and the CSF. 3 stages:a early:bulls-eye rash (erythema migrans) - absent in 50%general symptomsb early disseminated:10% have cranial neuropathy, meningitis. Some have iritis, retinitisc late:oligoarthritis in large joints (60%), which continues post-Lyme diseaseECM lesions lead from fatigue to dementiaChronic Lyme/Post-Lyme disease: resembles fibromyalgia and chronic fatigue, not caused by the infection.4. Diagnosis: by tissue culture from ECM. Serology - problem is you need to treat before you can see the Abs. ELISA followed by WB (similar to HIV test). Treatment: Early - amoxicillin or doxycycline. Late - IV ceftriaxone
peptidoglycan layer
or cell wall. Made up of repeating disaccharides with 4 amino acids in a side chain extending from each diaccharides
Vibrio cholarae can be found in humans and...
ocean epidemics
what after staph aureus is the second most responsible bacteria for IE?
strep viridans
Giardia lamblia: chronic giardiasis (symptoms, epidemiology)
epidemiology: toddlers
second to CF as cause of steatorrhea

symptoms
steatorrhea leading to increased fat excretion in stool
growth retardation
decreased serum carotene
abnormal xylose absorption
What bacterium is the most common cause of community-acquired urinary tract infections?
E. coli.
 
(Syllabus: 21-11)
Which cells primarily produce IFN-g?
NK cells and T cells
Environmenal Factors of Respiratory Disease (3)
1. occupation
2. day care
3. public transport
NA probes - Detection*
place specimen cells on filter; lyse cells & generate ss target DNA; add reporter-labeled probe; allow for reannealing to target; measure hybridization directly if reporter radioactive or fluorescent; add enzyme substrate if reporter enzyme; detect using radioactive detector, fluorimeter or colorimeter/visual inspection
Who is more susceptible to toxoplasmosis?
pregnant women -->during pregnancy, can give to fetusimmunocompromised patientsregular folks have few symptoms
What are the most common inhalation-associated pathogens in the following situations?1. CNS injury2. T cell deficiency3. IgG deficiency
1. aspiration pneumonia, abscesses. Caused by anaerobic streptococci, fusobacteria2. PCP, CMV3. infection by encapsulated microbes, e.g. pneumococcus
Deescribe the process of transduction
A bacteriophage infecting a cell accidentally puts a piece of bacterial DNA in its capsid instead of its own, then it infects another bacteria. That piece of DNA does homologous recombination with the host genome.- phages are usually host-restricted (i.e. happens between similar/same species)- host must have phage receptor
Leishmania spp1. Vector2. Geography3. Manifestations
1. Sandfly2. Central and South America, Middle East and Africa (Iraq - think veterans)3. Varies depends on the organism and host immune system. Can cause disfiguring skin ulcers, or can have visceral effects (=Kala azar - hepatosplenomegaly)
Life Cycle of Cestodes
eggs are passed in feces
eggs are eaten by intermediate host
larva develops in tissue
definitive host eats flesh of intermediate host
scolex attaches to wall of human intestine
adult worm grows
cycle repeats 
Matoux tuberculin skin test
inject small amount of PPD tuberculin into surface of skin, 48-72 hours later the injection should swell with redness larger than 15mm in a healthy person
40% of untreated women with chlamydia develope ___, and of those 40%, __% become infertile, __% experience debilitating, chronic ______ pain, and _% will have a life threatening tubal pregnancy.
PID; 20; 18; 9
Pneumocystis jirovecii (dx, tx for AIDS)
dx
sputum
bronchoalveolar lavage or biopsy
Giemsa or Gomori stain- stain black
methenamine silver stain- stain black
specific fluorescent monoclonal Ab stain

tx in AIDS
primary- when patient at risk (CD4 less than 200)
secondary- after patient had infection
amebic liver abscess symptoms
h/o symptoms for more than 4 weeks
fever
abdominal tenderness
hepatomegally
jaundice
diarrhea
weight loss
more common in men
cough
immigrant/traveler from endemic area
What is a siderophore?
Molecules with a high affinity for iron. E. coli produce them to steal our iron. Jerks!
 
(Syllabus: 21-7)
Which cells primarily produce IL-6?
Macrophages, endothelial cells and T cells
General features of isospora belli morphology
>infective oval oocysts with 2 sporocytes each>oocysts mature in 4 days>both sexual and asexual development in new epithelial cells
Viruses are Classified by: (4)
1. type of nucleic acid
2. size, shape, capsid
3. enveloped vs. naked
4. cell types they invade
Clinical signs of cutaneous Leishmania
>organisms stay in skin because they like the lower temperature better>forms ulcer with raised edges starting at the bite site.>can be scaring and spread.
Dermatophytes1. Yeast or mold?2. Where do they infect?3. Diagnosis
1. Molds2. Superficial keratin layer3. Skin scrapings ->culture or microscopy.
Syphilis diagnosis and treatment
Dx: can be by microscopy from skin scrapingsUsually done by serologyNon-treponemal:VDRL, RPR tests for Ab to cell membrane lipids and lecithin. The levels of these can be used to track how therapy is goingTreponemal:Antibodies to the bacteria itself - are positive for life and therefore can't be used to trackAlgorithm:ELISA for treponemal Ag, then if + RPR. If RPR- do treponemal Ab.Tx:Penicillin - highly effective
What bacterial pneumonias infect people who have the influenza A virus? What is the disease caused by the influenza A virus' primary infection?
Acute Lung disease is caused by Influenza A's primary infection, leading to infection by:
 
Streptococcus pneumoniae
 
Staphylococcus Aureus
Compare and contrast the morphology and biological properties of H. pylori and C. jejuni.
They are both curved, Gram-negative rods that are motile and microaerophilic. H. pylori grows well at 37°C, while C. jejuni prefers a tropical 42°C.
 
(Syllabus: 21-12)
What is the difference between Ab isotypes, allotypes and idiotypes?
Isotypes: different heavy chain constant region (IgE vs IgM); allotype: different polymorphic areas in the constant regions; idiotype: different variable region



Cell Damage or Death by Viruses as Pathogen
fuses cells: HSV, CMV
forms malignant transfromation: EBV, papilloma
cell death: rabies, polio
Name 3 parts of cestode.What is gravid?
scolex (head with hooks)neck (just behind head)Segments (proglottids)-segments, mature as get more posterior with eggs.Gravid=egg development complete segment
Trichomonas vaginalis1. Route of transmission2. Symptoms/Manifestations3. Diagnosis4. Treatment
1. STI2. Male - asymptomatic. Female - Vaginal irritation, soreness. Frothy discharge with characteristic fish odor3. Wet mount = pear shaped protozoa with flagella twitching around4. Metronidazole
what are the best tools in developing countries fo dxing diseases like rheumatic heart disease?
a good hx and physical
Life cycle of Echinococcus granulosus
adult worm lives in sheep dog small intestins
sheep ingest eggs and develops in liver

eggs are ingested
oncospheres hatch in small intestins
oncospheres enter bloodstream, penetrate tissue
cyst develops in liver or in another organalso you can have cysts in brain and lung
What are examples of acute phase proteins? what are their functions?
1. C-reactive protein (CRP), serum amyloid A, 2. bind to microbes to stimulate phagocytosis, also increase recruitment and activation.
What are the 2 species responsible for African Trypanosomiasis and where do they predominate?
T.b. gambiense - West Central AfricaT.b. rhodensiense - East southern Africa
Cultural gonorrhea is diagnosed by:
Taking a sample of a cervical swap or pus
 
Using a thayer martin media chocolate agar with antifungal agents, anti ram positive agents and anti gram negative enterics.
what after strep viridans is the second most responsible bacteria for IE?
CNS or coagulase negative staph such as staph epidermis
THIS E. coli infection is like EPEC, but with Shiga toxin.
What is EHEC (enterohemorrhagic E. coli)?
 
(Syllabus: 21-10)
What cause T cell integrins (LFA1) to increase their binding affinity for their ligand (ICAM1)?
TCR signals and chemokines (through receptor) released from APCs
What do the following serotypes of E. Coli correspond to?O148:H28O26:H11O157:H7O4:H5K1
O148:H28 = ETECO157:H7 = EHECO26:H11 = EPECO5:H4 = UTIK1 = meningitis
What are the three antigens used to distinguish different strains of E. coli?
O (surface--LPS), H (flagella), and K (capsule).
 
(Syllabus: 21-6)
How are T cells selected in the thymus?
T cells go through positive selection via thymic epithelial cells in the cortex and go through negative selection via dendritic cells in the medulla.
Candida spp1. 1st and 2nd most common infectious species2. Pathogenesis (normal habitat, etc.)3. Disease manifestations4. Treatment
1. C albicans (most common) and C Galbrata2. Normal flora of GI tract, mouth, vagina. - kept in check by local flora (AB therapy -> candidiasis) - kept in check by mucus membrane integrity (chemotherapy breaking down membranes and GI surgery -> candidiasis) - kept in check by immune system (corticosteroids and other IS -> candidiasis)3. A wide spectrum. Superficial infections of mouth (thrush), skin (diaper rash), esophagus, vagina. More seriously, can disseminate, causing blood infection, endocarditis, abscesses in multiple sites.4. Amphotericin, echinocandins, or azoles
I really want to get ETEC. How would I go about getting it, and what would I enjoy as my symptoms?
It's transmitted by contaminated food and water. It causes watery diarrhea.
 
(Syllabus: 21-8)
What are the two ways that NK cells kill targets?
1. Kill infected cells, 2. in response to IL-12 released by a macrophage with a phagocytosed microbe it will release IFN-g which stimulates the adaptive immune response and tells the macrophage to kill the microbe inside it.
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