Microbiology Flashcards
Which are the microorganisms produce intraerythrocytic infections? and which are their characteristics?
- babesia—- intraerythrocytic rings, vector— tick—coinfection with borrelia (lyme disease)
- plasmodium spp
Which streptoccocal components produce scalet fever?
erythrogenic toxin
which is the mechanism through influenzae virus achieve antigenic shift? and how explain it?
Reassortment: enchange genetic material, it is possible because of segmented genome.
which is the cause and main characteristics of the renal struvite stones?
- Urease positive microorganisms: Proteus, Cryptococcus, H pylori, Ureaplasma,
Nocardia, Klebsiella, S epidermidis, S saprophyticus - Calculus fill entire renal pelvis
Congenital toxoplasmosis triad
- Chorioretinitis
- Hydrocephalus
- Intracranial calcifications
Relate these conditions with some parasites
- biliary tract disease and cholangiocarcinoma
- liver hidatid cyst
- microcytic anemia
- myalgias
- Vit B12 deficiency
- Clonorchis sinensis
- Echinococcys granulosus
- Necator- ancylostoma
- Trichinella spiralis
- Diphyllobothrium latum
8 families of naked virus
Papilomavirus, adenovirus, parvovirus, polyomavirus, calicivirus, picornavirus, reovirus and hepevirus.
7 families of DNA virus and exceptions
- Herpesvirus, Hepadnavirus, Adenovirus, Polyomavirus, Poxvirus, Parvovirus, Papillomavirus
- All are dsDNA except parvovirus
- All replicate in nucleus except Porxvirus (carries DNA -dependent RNA polymerase)
which are the main C. difficile pathogenic factor?
alpha toxin (phospholipase C) is a lecithinase—-disrupts membranes, damaging RBCs, platelets, WBCs, endothelial cells— massive hemolysis, tissue destruction, hepatic toxicity.
Mechanisms of bacterial resistance to aminoglucosides
- poor drug penetration through bacterial membrane
- failure to drug binding to 30s ribosomal subunit due to mutation
- Drug destruction by bacterial enzymes
ADHD treatment
Methylphenidate and anphetamines: Increase releasing of norepinephrine and dopamine from vesicular storage sites.
Blocking NE and dopame reuptake
antibiotics against anaerobic bacterias
- piperacilin-tazobactam
- carbapenems
- clindamycin
- metronidazole
Protein A
Part of peptidoglycan layer—virulence factor of S. aureus —- binds to fc portion of IgG— inhibiting complement activation and phagocytosis.
Enterotoxigenic E. coli
heat level toxin (LT)
activate cAMP —- increased Cl in gut and H2O efflux
“Cholera like toxin”
travelers diarrhea
- Candida
- Blastomyces
- Pseudohyphae with blastoconideas, budding yeast
- yeast with distinctive broad beased budding
- coccidiomicoses
- Cryptococco
- Hystoplasma
- spherules with endospores
- capsule (india ink)
- small oval yeast within macrophages
Legionella pneumophila
Silver stains
charcoat yeast agar suplemmented cysteine and iron
contaminates natural water
pneumoniae, diarrhea, hyponatremia
Influenza virus vaccine
Inactivated version of vaccine—- inducing neutralizing abs against hemagglutinin antigen— prevents virus entering the cell via endocytosis
Germ tubes
true hyphae—- specific for Candida albicans
Primaquine
Mus be added to treatment regimen against P. vivax and ovale—- to erradicate hipnozoites
Haemophilus
requires X factor (hematin) V factor (NAD+) to support growth.
Will grow around B hemolytic S. aureus because secrete factor V
Streptococo
alpha, beta y gamma hemolytic
- alpha: viridans (optohin resistant and bilis insoluble). pneumoniae (optochin sensitive and bilis soluble)
- beta: pyogenes (pyr positive and bacitracin sensitive), agalactiae (pyr negative and bacitracin resistance)
- gamma: enterococcus (pyr positive, grow in 6.5% NaCl), bovis (pyr negative and not grow in 6.5% NaCl)
coccidiodes immitis
dismorphic fungus
microscopic examination: thick wall spherules with endospores
immunocompetent localized infection: lungs
immunocompromised: systemic infection
Streptococo pyogenes
Beta hemolytic
Coagulase- catalase negative
PyR positive
Bacitracin sensitive
Q fever
Coxiella burnetti
animal waste
Acute: non specific fever- fatigue- severe debilitating headaches retroorbital, photofobia, pneumonia, thrombocytopenia, increase liver enzymes
Chronic: fatal if is untreated, endocarditis if the patient has valvular disease
Clostridium difficile enterocolitis
toxin A (enterotoxic) and B (cytotoxic) Toxin B more virulent: inactvated rho regulatory protein---------involved in signal transduction and actin cytoskeletal structure maintenance --- disrupction of intercelleular tight junction. Damaged cytoskeletal integrity
Which is the main cause of septic shock and septicemia of meningitis by N. meningitidis?
Lipoolygosacharide (LOS)
Endotoxin
Dynein and kinesin
In herpes zoster dynein: retrograde transport (skin to nerve)
Kinesin: anterograde transport (nerve to skin)
West nile virus
fever, rash and neurologic manifestations
most common in erderly patients
encefalitis and flaccid paralysis
RNA virus– flavivirus, transmitted by mosquito (culex)
Saline microscopy
best diagnstostic test to identify trichomonas
Why is the difficult to develop vit c vaccine?
has 6 o more genotypes—-the virion encodes RNA dependent RNA polymerase without 3´-5´ proofreading exonuclease activity: results in many errors during replication. — hypervariable genomic regions—-such sequences coding envelope glycoproteins
Acute hepatitis B
Systemic, skin, joint symptoms, hepatomegaly and elevated transaminases (> 10 times over normal limit).
May develop a serum sickness like syndrome: joint pain, lymphadenopathy and prurituc urticarial vasculitis rash
could or not be icteric
Elevated Pt: poor prognosis
three main mechanisms for genetic transfer between bacteria
- transformation: bacteria take up naked DNA for the environment.
- Conjugation: DNA is passed from one bacterium to another by direct cell-cell interaction
- transduction: bacteriophage - mediated transfer of genetic information
Difference between reassortment and phenotypic mixing
phenotypic mixing: the progeny of new strain remain unchanged
Ressortment: any genomic change is always present in subsequent progeny
Hepatitis D and B relation
Hepatitis D antigen isconsidered replication defective as it must be coaled by exteral coat hep B surface antigen————-to PENETRATE hepatocyte
How could minimized recurrent HSV-2 recurrent lesions?
daily valacyclovir, acyclovir or famciclovir
minimized replication
Novobiocin test
applying in coagulase negative microorganisms,
sensitive: Staphylococcus epidermidis
Resistant: S. saprophyticus
The most mediator of sepsis?
TNF alpha
Ecthyma gngrenosum
P. aeruginosa
Exotoxin A (protein synthesis inhibitor)
Elastase(degrades elastin— blood vessel destruction)
Phospholipase C (degrades cellular membrane)
Pyocianin (generates ROS)
*** perivascular bacterial invasion of arteries and veins—- dermis and subcutaneous tissue.
Absolute neutrophil count
0.6* Number of leucocyte
If it is less than 500 /mm3 = neutropenia
Roseola infantum
HHV 6
3-5 days with fever ——- then a blanching maculopapular generalized rash
Ghon complex
initial infection of M. tuberculosis
lower lung lobe lesion (fibrotic focus) + ipsilateral hilar adenopathy
Common intracellular pathogens
Chlamydia, francicella, laegionella, listeria, mycobacterium, N. gonorrhea, nocardia, ricketssia, salmonella and yersinia
** Cell mediated immunes response: INF gamma, TNF alpha, and IL-2
outer membrane is characteristic of…
gram negative
contain: LPS and LOS
Bacillary angiomatosis
produced muy bartonella henselae in immunocompromised patients (catscratch). Vascular lesions in skin as papules, and in viscera
