Micro Flashcards
Prokaryotes or eukaryotes?
1. Cell wall containing peptidoglycan
- Membrane bound organelle
- Mitotic division
- Prokaryote
2 & 3. Eukaryote
Size of ribosome of prokaryotes & eukaryotes
Prokaryotes 70s (50s + 30s)
Eukaryotes 80s (60s + 40s)
Which of pathogenic microorganisms is prokaryotic?
Bacteria
Mobile genetic elemets, DNA piece that readily move from one site to another.
Also known as
Transposons aka jumping genes
Vacuolated neurons with loss of function and the lack of an immune response or inflammation
Spongiform encephalopathies
You can get it by cannibalism with cerebellar dyafunction (ex dystaxia)
Kuru
Bovinee spongiform encephalopathy(BSE)
Mad cow disease
Bacteria that are spirochetes
B-L-T
Bornelia
Treponema
Leptospira
- Smallest bacteria
- Largest bacteria
- Largest bacteria that is medically important
- Mycoplasma sp
- Thiomargarita namibiensis
- Bamelia burgdorferi
All bacteria have a cell wall composed of peptidoglycan except
Mycoplasma
Sugar backbone (glycan) + peptide side chains (peptido) cross linked by transpeptidazd
All gram positive bacteria have NO Endotoxin except
Listeria monocytogenis
- gram negative cells contains endotoxin, has Lipopolysaccharide & Periplasmic space
- gram positive cells have techoic acids
Gram staining
Primary stain
Mordant
Decolorizing agent
Counterstain
Crystal violet
Iodine
Alcohol/ acetone
Safranin
Bacteria not seen in gram stain
- Mycobacteria
- Spirochetes
- Mycoplasma spp
- Legionella spp
- Chlamydia
- Rickettsia
- Acid fast stain
- Darkfield microscopy
- None
- Silver stain
- Inclusion bodies
- Giemsa / tissue stain
Invagination of plasma membrane and participation in cell division and secretion
Mesosome
All bacterial capsules are composed of polysaccharide except
Bacillus anthracis (polypeptide of D-glutamate)
Bacterial growth curve
Phase 1-3 enumerate
Phase with zero growth rate, adaptation to new environment
Phase with rapid cell division
Phase 1 lag phase
Phase 2 log or exponential phase
Phase 3 maximum stationary phase
Phase 4 decline or death phase
Phase with exhaustion of nutrients of the accumulation of toxic products cause growth to cease completely (zero growth rate); spores are formed
Phase 3: Maximum Stationary Phase
Phase where most cells die because nutrients have been exhausted (negative growth rate)
Phase 4: decline or death phase
Oxygen metabolic generates toxic products such as _____ & ______
Superoxide & hydrogen peroxidase
Are neesed to survive in aerobic environments
Superoxide dismutase, peroxidase & catalase
2 aerobic
3 anaerobic
- Obligate aerobes
Microaerophiles - Facultative anaerobes
Aerotolerant anaerobes
Obligate anaerobes
- Utilize oxygen if it present, but can use fermentation in its absence
- Cannot grow in the presence of oxygen
- Use fermention but can tolerate low amounts bec they have superoxide desmutase
- Facultative anaerobes
- Obligate anaerobes
- Microaerophiles
- Exclusive anaerobic but insensitive to the presence of oxygen
Aerotolerant anaerobes
Remember: Obligate anaerobes 1. Actinomyces 2. Bacteroides 3. Clostridium
Obligate aerobes
- Neisseria
- Mycoplasma pneumonia
- Leptospira
- Pseudomonas
- Mycobacterium
- Bordetella
A measure of a microbe’s ability to cause disease
Virulence
Surface proteins are called _____ and 2 examples with it
Curli (salmonella.& e.coli)
Enzyme in bacteria which destroys both neutrophilic leukocytes and macrophages
Spread through subcutaneous tissue
Leukocidin
Collagenase & hyaluronidase
Accelerated formation of a fibrin clot coating the organisms with a layer of fibrin
Allows adherence to mucous membrane
Coagulase
IgA protease
Bacteria with IgA protease
SHINe My Gong
strep pneumonia
haemophilus influenza
Neisserria meningitidis
Neisseria gonorrhea
Difference of exotoxin & endotoxin in
- Heat stability
- Vaccines
- Typical disease
Exotoxin Endotoxin
- Destroys rapidly 1. Stable at
At 60c except staph. 100c for 1 hr
Enterotoxin - Toxoids. 2. No vaccines
- Tetanus, botulism. 3. Meningo
- Prevents complement activation
2. Widespread activation of the complement and coagulation cascades
- Protein A of S. Aureus
2. Superantugens
- All bacteria have cell walls composed of peptidoglycan except
- All bacterial capsules are composed of polysaccharides except
Mycoplasma pneumonia
Bacillus anthracis
Agar of the following
- N. Gonorrhea from nonsterile areas
- N. Gonorrhea from sterile areas
- Haemophilus influenza
- Clostridium perfringens
- Corynebacterium diphtheriae
- Staph
- Group D strep
- Thayer-martin
- Chocolate
- Chocolate + factors x and v
- Egg yolk
- Tellurite
- Mannitol salts
- Bile esculin
Read:
Mycobacteria tb : lowenstein-jensen
Vibrio cholera : thiosulfate-cutrate bile salts
Bordetla pertussis : bordet-gengou
Legionella pneumophilia : charcoal-yeast extract
Campy & helicobacter : skirrows
Borrelia burgdoferi : barbour-stoenner kelly
Mycoplasma pneumonia : eaton
Pseudomonas aeruginoa : cetrimide
Salmonella, shigella : xylose-lysine -deoxycholate
Leptospira interrogans : ellinghausen-mccullough-johnson-harris / fletcher
Cause cartilage dame and arthropathy in children
Quinolones
Bind to developing bone and tooth structurw, causing purplish brown discoloration of teeth, and even enamel hypoplasia
Tetracyclines
Slow acetylators of INH is at risk for __________
Fast acetylators like filipinos, is at risk for ___________
Polyneuritis
Hepatoxicity
2 drugs that binds to pus and get inactivated
Aminogycosides & polymixins
3 drugs that do not pass BBBB even with inflammation
Polymixin
1st and 2nd gen cephalosporins
Amphotericin b
Excellent for treatment of NCS infections w/ or w/o inflammation
-sulfonamides, chloramphenicol, fluconazole, rifampicin and isoniazid
Minimal or not good even with inflammation
-aminoglycosides, tetracyclines, lincosamides, macrolides
Major components of immune system
- b cell (antibody)
- t cell
- phagocytes
- complement
Recurrent infection with pyogenix bacteria indicate a ____ deficiency
Recurrent infections with fungi, viruses or protozoa indicate a ______ deficiency
B-cell deficiency
T-cell deficiency
Other term for x-linked aggamaglobulinemia?
Bruton’s agammaglobulinemia
- very low levels of immunoglobulins
- virtual absence of B crll due to tyrosine kinase mutation
- cell mediated immunity is normal
Treatment for x-linked / brutos aggamaglobulinemia
Pooled gamma globulin
Failure of isotype switching and recurrent bacterial sinus & lung infection.
Treatment?
Selective IgA deficiency
Treatment:
Defect in b-cell maturation to plasma cells
Most common form of severe antibody deficiency affecting both children and adults
Treatment?
Common variable immunodeficiency
Tx: pooled gamma globulin
Profound deficit of T cells
Failure of development of thymus and parathyroids
Due to a defect in 3rd and 4th pharyngeal pouches
Hummoral immunity is normal
Di george syndrome
-tetany due to hypocalcemia
Tx is transplant of fetal thymus
DiGeorge Syndrome
Catch-22
Cardiac defect (TOF) Abnormal facies Thymic aplasia Cleft palate Hypocalcemia 22q11.2 chromosomal deletion
Specific T-cell deficiency for Candida Albicans
Recurrent candidiasis in children
Chronic mucocutaneous candidiasis
Tx: azole antifungal drugs
X-linked: defect in IL-2 receptors in T-cells
Autosomal: ADA deficiency
Severe combined immunodeficiency (SCID)
-recurrent infection in early infancy
Tx: bone marrow transplant
x-linked (affects male infants)
Inability to mount IgM response
Wasp gene mutation
Wiskoyy-aldrich syndrome
Tx: bone marrow transplant
Tie a wasp
Thrombocytopenia
Infections
Eczem
IgA deficiency
Ataxia, telangiectasia, IgA deficiency
Autosomal recessive disease
Mutations in DNA repair enzymes
a-t-i
Ataxia telangiectasia
Ataxia
Telangectasia
IgA deficiency
Phagocyte disorder
Lack if nadph oxidase activity
Normal b and t cell
Chronic granulomatous
- recurrent infection with catalase-positive bacteria
- fungi
Tx: antibiotic chemop
Autosomal recessive disease
Failure of phagolysosomal fusion
Faulty microtubules impair neutrophil chemotaxis
Chediak higashi syndrome
Tx antibotics
Recurrent pyogenic infxn caused by staph and strep
Autosomal recessive disease Mutation in integrins Defective adhesions (LFA-1) proteins on the surface phagocytes
Leukocyte adhesion deficiency
-delayed separation of umbilical cord
Severe pyogenic infxn in infancy
Tx: antibiotics
2 complement disorders
Early complement deficiency
Terminal complement deficiency
Early - c2 & c3
Terminal c5-c9
Most common complement defect and usually asymptomatic
Recurrent pyogenic infxns due to staph aureus
Inability to form membrane-attack complexes, neisseria meningitidis & gonorrhea
C2 deficiency
C3 deficiency
Terminal complement deficiency
Tx: vaccination
Treatment for AIDS
Higly-active antiretroviral therapy (HAART)
Loss of cell mediated immunity
Infects and kills CD4 + helper T cells
B cells yes for everything except
T cell yea for everythinh except
B cells and t cells
Phagocytes, yes for
Complement
- Except fungi
- Except bacteria
- Yes all
- Phagocytes yes for fungi and bacteria
- Yes for bacteria alone
If catalase positive
If catalase negative
If coagulase positive
If coagulase negative
- Staphylococcus
- Streptococcus (chains)
- S. Aureus
- S. Epidermidis, S. Saprophyticus
Novibiocin resistant, novobiocin sensitive
Differentiate s. Epidermidis to S. Saphrophyticus
After novobiocin
S. sapro if resistant
S. Epidermidis if sensitive
Both catalase positive and coagulSe negative
Gram positive cocci in grape like clusters
B-hemolytic yellow or golden colonies
Salt tolerant on mannitol salts agar
Staph aureus
Habitat: human nose and skin
Mupirocin to eradicate
Virulence factor
- Protein A prevents complement activation
- Coagulase builds an insoluble fibrin capsule
Catalase detoxifies hydrogen peroxide
Hemolysins toxic to hemapoietic crlls
PV leukocidin specific for wbc
Penicillinase : inactivated penicillin derivatives
3 diseases you’ll find strawberry tongue
Scarlet fever
Kawasaki disease
Toxic shock syndrome
Novobiocin test
Novobiocin resistant - staph saprophyticus
Novobiocine sensitive - staph epidermidis
Scalded skin syndrome
Riter disease
2nd most common cause of UTIs in sexually active women
1st most common cause of utis
Staphylococcus saprophyticus
E. coli
- Catalase negative, gamma hemolytic
- Catalase neg, beta hem, bacitracin resistant
- Catalase neg, beta hem, bacitracin sensitive
Group d strep
Strep agalactiae
Strep pyogenes
Bile optochin sensitive?
Bile optochin resistant?
A. Step pneumoniae
B. Viridans streptococci
- A
2. B
Positie PYR test
Strep pyogenes
Group D streptococci
Protease that rapidly destroys tissue
Exotoxin B
Antibody that decrease efficacy of streptokinase in managing MI
Titers to document antecedent skin infection
Anti streptokinase
Anti-dnase b
Perioral blistered lesions wih honey colored crust. Accumulation of neutrophils beneath stratum corneum
Impetigo contagiosa
Superficial infection extending into dermal lympatics
Deeper infection involving subcutaneous/dermal tissues
Rapidly progressive infxn of deep subcutaneous tissues
Erysipelas
Cellulitis
Necrotizing fasciitis
Due to erythrogenic toxin, seen in lysogenized strains fever, strawberry tongue, centrifugal rash, sandpaper like, pastia’s lines, desquamation
Scarlet fever
Streptococcal toxic shock syndrome is due to
Pyogenic exotoxin A
Acute rheumatic fever
JONES CRITERIA
- Migratory polyarthritis
- Pancarditis
- Erythema marginatum
- Sydenham chorea
Subcutaneous nodule
Glomerulonephritis ssx:
DOC: parenteral and oral
Hematuria, htn & periorbital edema
Parenteral : pen G
Oral : pen V
Grow using LIM BROTH
Group b strep aka strep agalactiae
Hydrolyze hippurate
And camp test positive
Group b strep
Treatment for group b strep
Pen g!
For serious infxn pen g *+ aminoglycoside
All pregnant women should be screen for GBS colonization
35-37 weeks AOG
Gamma (nonhemolytic) colonies
Bile and optochin resistant
Can grown in 6.5 % nacl
Other term
Group d step
Aka enterococcus faecalis
UTis due to indwelling urinary catheters & urinary tract instrumentation
Group D strep
Treatment for group d strep
Penicillin plus gentamycin
Vancomycin
Linezolid
Gram positive lancet shaped cocci in pairs
strep pneumonia
-alpha hemolytic
Positive quelling reaction
Strep pneumoniae
Optochin sensitivity
Optohin
Viridans resistant
Pneumonia sensitive