yibopugu's version from 2015-09-13 21:34

Bacterial Taxonomy What is the stain and Morphology of each bacterium?

Question Answer
StaphylococcusCoccus (circular) Gram positive, Catalase positive
S. AureusCoccus Gram Positive, Catalase positive, Coagulase positive
S. EpidermidisCoccus Gram Positive, Catalase positive, Coagulase negative,Novobiocin sensitive
S. SaprophyticusCoccus Gram Positive, Catalase positive Coagulase negative, Novobiocin resistant
StreptococcusCoccus Gram Positive, Catalse negative
Strep. PneumoniaeCoccus Gram Positive, Catalase negative, alpha hemolytic,optochin sensitive, capsule (quellung positive)
Strep. viridansCoccus Grams Positive, catalase negative, alpha hemolytic, optochin resistant, no capsule
Strep. pyogenesCoccus Gram Positive, catalase negative, beta hemolytic, bacitracin sensitive
Strep. agalactiaeCoccus Gram Positive, catalase negative, beta hemolytic, bacitracin resistant
Enterococcus faecalisCoccus Gram Positive, catalase negative, gamma hemolytic
Strep. BovisCoccus Gram Positive, catalase negative, gamma hemolytic, does not grow in bile, 6.5% NaCl
ClostridiumGram Positive Bacilli (rods), Anaerobes - spore forming
ListeriaGram Positive Bacilli (rods),motile, non spore forming
Corynebacterium DiphtheriaeGram Positive Bacili, non motile, non spore forming; Tellurite plate, Loffler's media
PseudomonasGram Negative Bacilli, Lactose nonfermenter,oxidase positive
ShigellaGram Negative Bacilli, lactose nonfermenter, oxidase negative
SalmonellaGram Negative Bacili, lactose nonfermenter, oxidase negative
ProteusGram Negative Bacili, lactose nonfermenter, oxidase negative
KlebsiellaGam Negative Bacili, lactose fermenter - fast fermenter
E. coliGram Negative Bacili, lactose fermenter - fast fermenter
Campylobacter jejuniGram Negative Coma-Shaped, oxidase positive, grow in 42C
Vibrio CholeraeGram Negative Coma Shape, oxidase positive, grow in alkaline media
Neisseria meningitidis Gram negative diplococci. maltose fermenter
Neisseria gonorrheaGram negative diplococci, maltose non-fermenter, VPN media or Thayer Martin
Haemophilus influenzaeGram negative coccobacilli, Chocolate agar with factor V (NAD) and X (hematin)
Bordetlla PertusisGram negativecoccobacilli, Bordet-Genghou agar
Mycoplasma PneumoniaeLowenstein Jensen agar, Ziehl Neelsen (carbol-fuchsin)
Mycoplasma TuberculosisEaton's agar, Ziehl Neelsen (carbol-fuchsin)
Lactose fermenting entericsPink colonies on MacConkey's agar
LegionellaCharcoal yeast extract agar buffered with cysteine and iron, silver stain
Which microbes are stained with Giemsa?Borrelia, Plasmodium, trypanosomes, Chlamydia
Which microbes do not stain well?Treponema, Ricketrsia, Mycobacteria, Legionella Pneumophila, Chlamydia

Microbe Special Groups

Question Answer
Which bacteria are obligate aerobes?Nocardia, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Bacillus (Nagging Pests Must Breathe)
Which bacteria are obligate anaerobes?Clostridium, Bacteroides, Actinomyces (Anaerobes Can't Breath Air)
Which enzymes do obligate anaerobes generally lack?Catalase, superoxide dismutase
Which bacteria are obligate intracellular?Rickettsia, Chlamydia (Stay inside cells when it is Really Cold)
Which bacteria are facultative intracellular?Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Yersinia Pestis (Some Nasty Bugs May Live FacultativeLY)
Which bacteria are encapsulated or quellung positive?Streptococcus Pneumoniae, Haemophilus influenzae type B, Neisseria meningitidis, Salmonella, Klebsiella pneumoniae, group B strep. (SHiN SKiS)
Which bacteria do asplenic individuals are at risk for severe infection?S. Pneumoniae. H. Influenzae, N. Meninigitidis, Salmonella, Klebsiella pneumoniae
Which organisms are catalase positive?S. aureus, Serratia, Pseudomonas, Actinomyces, Candida, E.coli
Which organisms are urease positive?Proteus, Ureaplasma, Nocardia, Cryptococcus, H. Pylori, Klebsiella (PUNCH K)
What pigment does Actinomyces Israelli produce?Yellow (Israel has yellow sand)
What pigment does S. aureus produce?yellow pigment
What pigment does Pseudomonas aeruginosa produce?blue-green pigment
What pigment does Serratia marceescen produce?red pigment
Which bacteria produce IgA proteases?S. pneumoniae, H. influenzae type B, and Neisseria (SHiN)
Which baterium undergo lysogeny, specialized transduction of toxins?ShigA-like toxin, Botulinum toxin, Cholera Toxin, Diptheria Toxin, Eythrogenic toxin of Streptococcus pyogenes

Endotoxins vs. Exotoxins

Question Answer
Source for ExotoxinCertain species of gram positive and gram negative bacteria
Source for EndotoxinOuter cell membrane of most gram negative bacteria
Exotoxin secreted?yes
Endotoxin secreted?no
Chemical composition of exotoxin?Polypeptide
Chemical composition of endotoxin?Lipopolysaccharide (structural part of bacteria, released when lysed)
Where is the location of genes for exotoxin?Plasmid or bacteriophage
Where is the location of genes for endotoxin?Bacterial chromosome
What are the clinical effects of endotoxins?Fever, shock
What is mode of action for endotoxins?Induces TNF and IL-1
What is the antigenicity of exotoxins?Induces high-titer antibodies called anti-toxins
What is the antigeniciy of endotoxins?Poorly antigenic
Vaccines for exotoxins?Toxoids used as antibodies
Vaccines for endotoxins?No toxoids formed and no vaccine available
Heat stability of exotoxins?Destroyed at 60 C (except for staphylococcal enterotoxin)
Heat stability of endotoxins?Stable at 100C for 1 hour

Bugs with Exotoxins

Question Answer
Which organisms inhibit protein synthesis?Corynebacterium diphtheriae, Pseduomonas aeruginosa, Shigella spp., E.coli (EHEC) including O157:H7
Which organisms inactivate EF-2 (elongation factor)?Corynebacterium diphtheriae, Pseudomonas aeruginosa
What is the toxin produced by C. Diphtheriae and its clinical manifestation?Diptheria toxin causes Pharyngitis and pseudomembrane in throat
What is the toxin produced by Pseudomonas aeruginosa and its clinical manifestation?Exotoxin A causes host cell death
Which organisms inactivate 60s ribosome by cleaving RNA?Shigella spp. E.coli EHEC including O157:H7
What is the toxin produced by Shigella and its clinical manifestation?Shiga toxin (ST) causes GI mucosal damage --> dysentry, ST also enhances cytokine release, causing HUS
What is the toxin produced by E.coli (EHEC) including O157:H7 and its clinical manifestation?Shiga-like toxin (SLT) causes enhances cytokine release, causing HUS, unlike Shigella, EHEC, does not invade host cells.
Which organisms increase fluid secretion?ETEC, Yersinia Enterocolitica, Bacillus anthracis, Vibrio Cholera
Which organisms increase fluid secretion by increasing intracellular cAMP levels?ETEC, Bacillus anthracis, Vibrio Cholerae
Which organisms increase fluid secretion by increasing intracellular cGMP levels?ETEC; Heat stabile toxin (stimulates guanylate cyclase)
What is the toxin produced by ETEC and its clinical manifestation?Heat Labile toxin (LT) and Heat Stabile (ST) Toxin causes watery diarrhea ; Heat labile toxin (ADP-Ribosyl Transferase activates GPCR adenly cyclase) and Heat Stabile toxin (stimulates guanylate cyclase)
What is the toxin produced by Yersinia Enterocolitica and its clinical manifestation? Heat Stable toxin causing watery diarrhea
What is the toxin produced by Bacillus Anthracis and its clinical manifestation?Edema factor which causes edematous borders of black eschar in cutaneous anthrax
What is the toxin produced by Vibrio Cholera and its clinical manifestation?Cholera toxin which causes voluminous "rice water" diarrhea; Cholera toxin AB toxin (ADP-ribosyl transferase) constituviely activates adenyl cyclase, leading to increased cAMP --> cAMP inhibits absorption across the epithelium and causes secretion of electrolytes
What is the toxin produced by Bordetella Pertussis and its clinical manifestation?Pertussis toxin, whooping cough - cough on expiration and whoops on inspiration
Which organisms inhibit neurotransmitter release with the cleaving of SNARE proteins?C.Tetani and C. Botulinum
What is the toxin produced by Clostridium tetani and its clinical manifestation?Tetanospasmin, causes muscle rigdity and "lock jaw"; toxin prevents release of inhibitory (GABA and glyine) neurotransmitters in spinal cord
What is the toxin produced by Clostridium botulinum and its clinical manifestation?Botulinum toxin, causes Flaccid paralysis, floppy babyl toxin prevents release of stimulatory (Ach) signals at musculoskeletal junction, --> flaccid

Bacterial growth curve

Question Answer
What is the lag phase?metabolic activity without division
What is the exponential/log phase ?rapid cell division. Penicilin and cephalosporins act here as peptidoglycan is being made.
Stationary phase?nutrient depletion slows growth. Spore formation in some bacteria.
Death phase?prolonged nutrient depletion and build up of waste products lead to death.

Causes of Pneumonia- What is it?

Question Answer
What is you differential for lobar pneumonia?Streptococcus pneumonia, Klebsiella pneumonia
What is your differential for broncho pneumonia?Staphlycoccus aureus, Haemophilus influenzae, Pseudomonas aeruginosa, Moraxella catarrhalis, Legionella pneumophila
What is your differential for interstitial pneumonia?Mycoplasma pneumoniae, Chlamydia pneumoniae, Respiratory synctial virus, cytomegalovirus, influenza virus, coxiella burnetti
What is your differential for aspiration pneumonia?Bacteroides, Fusobacterium, and Peptococcus
Most common cause of atypical pneumonia, usually affects young adults (classically, military recruits or college students living in a dormitory). Complications include autoimmune hemolytic anemia (IgM against I antigen on RBCs cayses cold hemolytic anemia) and erythema multiforme. Not visible on gram stain due to lack of cell wall.Mycoplasma Pneumoniae
Second most common cause of atypical pneumonia in young adultsChlamydia pneumonia
Most common cause of atypical pneumonia in infantsRespiratory Synctial virus (RSV)
Atypical pneumonia with posttransplant immunosuppresive therapyCytomegalovirus (CMV)
Atypical pneumonia in the elderly, immunocompromised, and those with preexisting lung disease. Also increases the risk for superimposed S. aureus or H. influenzae bacterial pneumoniaInfluenza virus
Atypical pneumona with high fever (Q fever); seen in farmers and veterinarians (the spores are deposited on cattle by ticks or are present in cattle placentas)Coxiella burnetti
Hos is Coxiella burnetti different from other rickettsiae?1) It causes pneumonia 2) it does not require arthropod vector for transmission (survives as high heat resistant endospores) and 3) does not produce a skin rash
Most common cause of secondary pneumonia (bacterial pneumonia superimposed on a viral upper respiratory tract infection), often complicated by abscess or empyemaStaphlyococcus aureus
Common cause of secondary pneumonia and pneumona superimposed on COPDHaemophilus influenzae
Pneumonia in cytic fibrosis patientsPseudomonas aeruginosa
Community acquired pneumonia and pneumonia superimposed on COPDMoraxella catarrhalis
Communityacquired pneumonia, pneumonia superimposed on COPD, or pneumonia in immuncompromised states; transmitted from water source. Intracellular organism that is best visulaized by silver stainLegionella pneumophila
Most common cause of community acquired pneumonia; usually seen in middle aged adults and elderlyStreptococcus pneumoniae
Affects malnourished and debilitated individuals, especially eldely in nursing homes, alcoholic, and diabetic enteric flora that is aspirated. Thick mucoid capsule results in gelatinous sputum (currant jelly), often complicated by abscessKlebsiella Pneumoniae
Is generalized asymptomatic, resulting in focal caseating necrosis in the lower lobe of the lung and hilar lymph nodes, Foci undergo fibrosis and calcification forming Ghon complexPrimary TB
Reactivation is commonly due to AIDs; may also be seen in aging; Occur at apex of the lung (high oxygen tension); Forms cavitary foci of caseous necrosis; may also lead to miliary pulmonary or bronchopneumonia. Clinical features include fevers and night sweats, cough with hemoptysis, and weight loss; Biopsy reveals caseating granulomas; AFB stain reveals acid fast bacilliSecondary TB infection