Hersh's high yield things

Question 1

Streptococcus pyogenes

Answer 1

Gram + cocci in chains, catalase negative
B hemolytic, bacitracin sensitive, and pyrrolidonyl arylamidase (PYR) positive
transmitted by direct contact and respiratory droplets
-m ptn associated with acute glomerulonephritis.
Also contains several spreading fators including exotoxins A-C which cause pyrogeneiss and erythrogenesis.
Can cause pharyngitis, rheumatic fever (post infection), scarlet fever and pyroderma/impetigo

Question 2

Streptococcus agalactiae

Answer 2

Gram + cocci in chains, catalase negative.
Beta hemolytic and bacitracin RESISTANT
can hdrolyze hippurate and is CAMP test positive
Reservoir in the human vagina and GI and can be transmitted to newborns (prolonged labor after rupture of membranes)

Question 3

Streptococcus pneumoniae

Answer 3

Gram positive cocci, catalase negative, alpha hemolytic, optochin snsitive, lancet shaped diplococci and lysed by bile
reservoir in upper respiratory tract.
capsule makes it dangerous in asplenic patients and causes a positive Quellung rxn
most common cause of typical pneumonia especially in pts. in the 60s
Also the most common cause of adult meningitis

Question 4

Viridans streptococci

Answer 4

Gram positive cocci in chains, catalase negative. alpha hemolytic and optochin RESISTANT
normal flora of the human oropharynx
biofilm makes it dangerous for damaged heart valves (subacute endocarditis) and for dental caries

Question 5

Enterococcus faecalis

Answer 5

Catalase negative PYR+
Group D gram positive cocci in chains
can hydrolyze esculin in 40% bile and 6.5 NaCl
common cause of urinary and biliary tract infections
can cause subacute endocarditis in the elderly due to damaged heart valves

Question 6

Bacillus Anthracis

Answer 6

Gram positive rod that can form spores
Aerobic
Large boxcar-like appearance
toxin contains a protective antigen, lethal factor and edema factor
Can give a toxoid vaccine for high risk individuals

Question 7

Bacillus Cereus

Answer 7

Gram positive rod that can form spores
Aerobic
Found in nature
Associated with food that is kept warm, not hot
Has emetic preformed toxin associated with fried rice and a diarrheal toxin (watery diarrhea)

Question 8

Clostridium Tetani

Answer 8

Gram ositive spore forming rod that is anaerobic
has a “tennis racket” appearance under the microscope
Toxin formed binds to ganglioside receptors and blocks the release of glycine and GABA at spinal synapses, causing extreme muscle spasm
Organism is rarely isolated

Question 9

Clostridium botulinum

Answer 9

gram positive spore forming rod that is anaerobic
reservoir is dirt and udst
can be transmitted via food or via traumatic tansplantation
toxin is and A-B polypeptide neurotoxin that is highly toxic and heat liabile. Blocks the release of acetylcholine at the myoneuronal junction resulting in flaccid paralysis
Can be a problem for canned foods or in children that ingest honey

Question 10

Clostridium perfringes

Answer 10

Gram positive spore forming rod that is anaerobic
Stormy fermentation in milk media
Double zone of hemolysis
Foodborne and traumatic implantation
Identified by the Nagler rxn
Can cause gas gangrene and food poisoning

Question 11

Clostridium difficile

Answer 11

Gram positive spore forming rod that is anaerobic
has toxin A and B which damage the mucosa leading to fluid increase and lead to cytopathology, respectively
cause of pseudomembranous colitis
DOC is metronidazole

Question 12

Listeria monocytogenes

Answer 12

gram positive non-spore forming rod that is faultative intracellular
exhibits tumbling motility
can grow in the cold of the refrigerator in soft cheeses and hot dogs
can cause severe neonatal disease
MCC of meningitis with in renal transplant patients and adults with cancer

Question 13

Corynebacterium diptheriae

Answer 13

gram positive rod that is non-spore forming aerobic
club shaped
not invasive, the toxin causes an inhibition of ptn synthesis by adding ADP-ribose to eEF-2
Causes the appearance of a dirty gray pseudomembrane and can cause recurrent laryngeal nerve palsy and lower limb polyneuritis

Question 14

Actinomyces israelii

Answer 14

Anaerobic gram positive branching rod that is non-acid fast
normal flora of gingival crevices and in the female genital tract
disease causes “sulfur “ granules in exudate that can be used for microscopy or culture
only in tissues with low oxygenation
also, can cause a solitary brain abscess, NOT multiple abscesses

Question 15

Nocardia asteroides, nocardia brasiliensis

Answer 15

Gram positive branching rod that is aerobic and partially acid fast
Found in soil and dust
Can cause MULTIPLE brain abscesses if it spreads to CNS
No toxins or virulence factors are known

Question 16

Mycobacterium tuberculosis

Answer 16

Acid fast rods that are obligate aerobes
contains mycolic acids highly resistant to desiccation and many chemicals including NaOH
Appears fluorexcent apple green with auramine-rhodamine staining
Produces a heat sensitive catalase active at body temp.
Faculataive intracellular organism that can produce sulfatides, chord factor, and a surface protein that can cause delayed hypersensitivity and cell mediated immunity
Causes the formation of a Ghon complex(usually in the periphery of the lung)

Question 17

M avium intracellulare

Answer 17

Acid Fast rods that are obligate aierobes
Contains mycolic acids highly resistant to desiccation and many chemicals including NaOH
Causes pulmonary, GI, and disseminated disease
Presents in AIDS patients, cancer patients, and those with chronic lung disease
Nonchromogen
Tread AIDS patients prophylactically for this iwith a CD4 of less than 50
Macrolide plus ethambutol

Question 18

M Kanasasii

Answer 18

Acid fast rods that are obligate aerobe
Contains mycolic acids highly resistant to desiccation and many chemicals including NaOH
Causes pulmonary, GI , and disseminated disease
Presents in AID, cancer, and those with chronic lung disease
*Photochromogen
Treat AIDS pts phrophylactically for this with a CD4 of less than 50… again, Macrolide plus ethambutol

Question 19

M. Scrofulaceum

Answer 19

Acid fast rods that are obligate aeorbes
contains mycolic acids highly resistant to desiccation and many chemicals including NaOH
Can cause lymphadenitis
Transmitted via contaminated water sources
PResents as solitary cervical lymphadenopathy in children
Scotochromogen
Treat with surgery*

Question 20

M Marinum

Answer 20

Acid fast rods that are obligate aerobes
Contains mycolic acids highly resistant to desiccation and many chemicals including NaOH
Soft tissue infections
***Fish Tank one****
transmitted via abrasions
Presents in tropical fish enthusiasts
Photochromogen
Treat with INH, rifampin, or ethambutol

Question 21

Mycobacterium eprae

Answer 21

Acid fast rods that are obligate Aeorbes
Contains mycolic acids highly resistnat to desiccation and many chemicals including NaOH
Causes Hansesn’s disease
found via punch biopsy
Optimal growth at less than body temprerature
Transmitted via nasal discharge in untreated patients
Can have a strong CMI response or weak CMI
the former being more desirable
Give dapsone for close family contacts to prevent spread

Question 22

Neisseria meningitidis

Answer 22

gram negative diplococci with flattened sides
oxidase positive
particularly kidney bean shpaed
large capsule that can be picked up via latex partice agglutination
grows on chocolate agar and ferments maltose
can cause meningitis and waterhouse-friiderichsen syndrom
common in young adults with meningitis

Question 23

neisseria gonorrhoeae

Answer 23

gram negative diplococci with flattened sides
oxidase positive
reservoir is the human genital tract
sensitive to drying and cold
uses pili to attach to mucosal surfaces and has widely varying antigens
diesease presents as urethritis, proctitis, endovervicitis, PID, arthritis, procititis, and ophthalmia and rapid blindness when in newborns
Culture on Thayer-Martin medium (selects for pathogenic strains)

Question 24

Moraxella catarrhalis

Answer 24

Gram negative diplococcus that is a normal upper respiratory tract flora
most common cause of otitis media and sinusitis
most strains produce a beta lactamase

Question 25

Pseudomonas Aeruginosa

Answer 25

Gram negative rod that is oxidase positive Aerobic (nonfermenting Pyocyanin pigment and fluroexcent expression Can present with a grape-like odor on culture and has a slime layer has non-lactose fermenting colonies on EMB or MacConkey agar Umiquitous in water Exotoxin ADP ribosylates eEF-2, inhibiting protein syntheseis and the liver is the primary target can cause hot tub folliculitis,eye ulcers, and cellulitis in burn patients (blue-green puss) can be a major problem as a cause of typical pneumonia in patients with CGD or CF

Question 26

Legionella Pneumophila

Answer 26

Weakly gram negative organism that usually needs a fluorescent AB test to be visualized Requires cysteine and iron for growth in media No human to human transition; water organism Facultative intracellular (granulomatous response) Common problem in smokers over age 55 with high slcohol intake and in immunosuppressed patientss (renal transplant) Associated diseases are common due to air-conditioning systems that are unclean

Question 27

Francisella Tularensis

Answer 27

Gram negative small rod organism that is a facultative intracellular pathogen Can cause "rabit fecer" as a a zoonist Can be transmitted via dermacentor tick bites, traumatic implantation, aerosols, and via ingestion Treat with streptomycin

Question 28

Bordetella Pertussis

Answer 28

Gram negative small rods that are strict aerobes Encapsulated attaches to nasopharyngeal ciliated epithelial cells via filamentous hemagglutinin Toxin also aids in attachment Toxin causes lymphocytosis promotion, islet activation (can cause hypoglycemia), immune cell effector blockage, and increased histamine sensitivite Organism causes WHOOPING COUGH and is easiest to diagnose in the catarrhal stage (1-2 weeks) even though this tage does not have the typical cough the paroxysmal stage has the typical symptoms, but harder to find the organism in this stage Vaccination is protective

Question 29

Brucella abortus (cattle), melitensis(goats), and suis (pigs)

Answer 29

Gram negative rod that is aerobic zoonosis faculataive intracellular pathogen that is a potential biowarfare agent Causes an undulant fever usually when drinking unpasteurized milk or via work in a slaughterhouse

Question 30

Campylobacter jejuni

Answer 30

Gram negative curved rods with polar flagella looks like "gull's wings" Oxidase positive Microaerophilic, and grows well at 42 degrees C. Need as few as 500 organisms to be infectious Cases gastroenteritis with possibly 10 or more flankly bloody stools per day Can be a cause of Guillain Bare syndrom (serotype ):19. treatment is mostly supportive)

Question 31

Helicobacter pylori

Answer 31

spiral shaped gram negative bacilli with flagella Urease positive Causes chronic gastritis and duodenal ulcers

Question 32

Vibrio Cholerae

Answer 32

Gram negative curved rod with polar flagella Osidase positive and can grow on alkaline media Shooting start motility Fecal oral spread (sensitive to acid) Enterotoxin that ADP ribosylates Gs alpha, causing eflux of Fl and water RICE WATER STOOLS

Question 33

Vibrio parahaemolyticus

Answer 33

Gram negative curved rod with polar flagella oxidase positive and can grow on alkaline media Transmitted through undercooked seafood Causes self-limited gastroenteritis

Question 34

Vibrio vulnificus

Answer 34

Gram negative curved rod with polar flagella oxidase positive and can grow on alkaline media spread through swimming in blackish water or via consumption of raw seafood can cause gastroenteritis and cellulitis based on innoculation site difficult to treat if cellulitis; can require amputation

Question 35

Enterotoxogenic Escherichia coli (ETEC)

Answer 35

Gram negative rod that is facultative anaerobe Ferments glucose and lactose and is cytochrome C oxidase negative Can Reduce nitrates to nitrites Catalase positive, oxidase negative Can cause recurrent infections in patients with CGD Most common cause of UTIs and the second most common cause of neonatal meningitis Has a heat labie toxin that stimulates adenylate cyclase and a heat stable toxin that stimulated guanylate cyclase Causes non-inflammatory diarrhea *Rehydrate*

Question 36

Enteropathogenic E. Coli (EPEC)

Answer 36

Gram negative rod that is a facultative anaerobe Ferments glucose and lactose and is cyt c oxidase negative Can reduce nitrates to nitrites Catalase positive, oxidase negative Can cause recurrent infections in patients with CGD Most common cause of UTIs and the second most common cause of neonatal meningitis Causes noninflammatory diarrhea in babies of developing countries Adheres to M cells

Question 37

Enteroinvasive E. Coli (EIEC)

Answer 37

Gram negative rod that is a facultative anaerobe Ferments glucose and lactose and is cytochrom C oxidase negative Cand reduce nitrates to nitrites Catalase positive , oxidase negative Can cause recurrent infections in patients with CGD Mot common cause of UTIs and the sencond most common cause of neonatal meningitis *Invades the large bowel and causes inflammatory diarrhea* Can form actin fet trails

Question 38

Enterohemorrhagic E. Coli (EHEC)

Answer 38

Gram negative rod that is a facultative anaerobe Ferments glucose and lactose and is cytochrome C oxidase negative Can reduce nitrates to nitrites Catalase positive, oxidase negative Can cause recurrent infections in patients with CGD Most common cause of UTIs and the second most common cuase of neonatal meningitis Verotoxin producer which decreases protein synthesis by interfering with the 60S ribosomal subunit NOT invasive Antibiotics will increase the risk of HUS

Question 39

Klebsiella pneumoniae

Answer 39

Gram negative rods that have a capsule Causes the creation of a currant-jelly sputum can cause UTIs in association with catheters Oxidase negative and forms mucoid, lactose fermenting colonies on MacConkey agar Endotoxin causes septicemia Pneumonia of those who are alcoholics

Question 40

Shigella sonnei, flexneri, dysenteriae, boydii

Answer 40

Gram negative rod that is a non-lactose fermenter Non-motile spread via the fecal oral route Invades M cells and very shallow ulcers form Toxin is neurotoxic, cytotoxic, and enterotoxic Clips the ribosomal 60X subunit Disease characterized b a high fever, lower abdominal cramps, tenesmus, diarrhea (watery progressing to bloody) Severity depends on the patients age and on the strain

Question 41

Yersinia pestis

Answer 41

Gram negative rod that bipolar stains Facultative intracellular parasite and is coagulase positive Spread by fleas that vomit up the organism due to coagulase Can be spread via fleas or via respiratory droplets Causes bubonic Plague or pneumonic plague

Question 42

Yersinia enterocolitica

Answer 42

motile gram negative rod at 25C, but non motile at body temp Cold growth transmitted in unpasturized milk and in pork Prominent in northern climates Causes enterocolitis as pseudoappendicitis in kids and young adults and can cause reactive arthritis in adults

Question 43

proteus mirabilis vulgaris

Answer 43

gram negative rod that has peritrichous flagella EXTREMELY motile Non lactose fermenting and urease positive Facultative anaerobe, oxidase negative Can cause staghorn renal calculi (flank pain) Can cause UTIs

Question 44

salmonella typhi

Answer 44

gram negative rods that are non lactose fermenter Produces H2S and is sensitive to acid No animal reservoirs organism resides in the gall bladder Can resist macrophage killing Symptoms of disease include FEVER headache, abd. pain, constipation (more common than diarrhea) and can lead to necrosis of peyer patches if left untreated Thrombophlebitis, cholecystitis, pneumonia, abscess formation, etc.

Question 45

Salmonella enteritidis, typhimurium

Answer 45

Facultative gram negative rod, non lactose fermenting on EMB or MacConkey medium Motile and produces H2S Can detect antibodies in serum via the Widal test Transmitted largely through chicken products and reptile pets Needs a large innoculation dosage due to acid sensitivity Sickle cell disease with this infection predisposes to osteomyelitis MCC in these patients Culture on Hektoen agar (black colonies)

Question 46

Haemophilus influenzae

Answer 46

Gram negative pleomorphic rod Requires growth factors X and V for growth on nutrient or blood agar Has a polysaccharide capsule Causes meningitis commonly in unvaccinated children aged 3 months to 2 years Can cause bronchitis, pneumonia and epiglottitis in unvaccinated toddlers (children present with "catcher's stance" to aid in breathing)

Question 47

Haemophilus Ducreyi

Answer 47

Gram negative pleomorphic rod Requires growth factors X and V for gorowth on nutrient or blood agar Has a polysaccharide capsule Reservoir in human genitals and causes very painful soft chancres