Step 1 - Bacteria (2)

colamember's version from 2016-12-07 18:02

Gram negative

Question Answer
Gram negative diplococci that look kidney shapedneisseria meningitides and gonorrhea
Army recruits, dorm dwellers at risk of infection by thisneisseria meningitidis
Gram negative with polysaccharide capsuleneisseria meningitides
Waterhouse Friedrichsen syndromeadrenal hemorrhage associated with N meningitides
Meningitis in infants (not neonates)neisseria meningitidis
How does meningitis in infants present? How can this be different than adults?Infants maybe just have fever, lethargy, vomitting, irritability. Adults and older children have classic stiff neck, brudzinski/kernig signs
Thayer Martin VCN mediaonly grows neisseria species
Meningococcal pili important for adherence tonasopharynx epithelial cells then get into vasculature then disseminate . Also has IgA protease to help it survive at mucosa
Treatment of neisseria meningitidisceftriaxone
Most common sexually transmitted diseases?chlamydia and N gonorrheae
Gonorrheae virulence factorspili that bind to epithelial cell surface
Gonorrheae in men causesurethritis
gonorrhea in women causesabdominal pain, painful intercourse, cervical discharge
Cervical motion tenderness, abdominal pain, fever, discharge, irregular bleedingPID
Fitz Hugh Curtiz syndromeinfection of liver capsule. Complication of PID
Scarring of fallopian tubes/infertility/fallopian ectopic pregnancy increased riskPID
Septic arthritis in sexually active individualsgonorrheae
opthalmia neonatorumgonococcus infection in newborns - can cause blindness via corneal damage
Newborns receive erythromycin eye drops to preventophthalmic infection by N gonorrheae
Treatment for sexually trasmitted gonorrheaCeftriaxone + azithromycin/doxy to cover chlamydia
HACEKculture negative endocarditis. Haemophilus, actinobacillus, cardiobacterium, eikenella, kingsella
Enterics are typically gram negativerods
ETEC toxinsST (heat stable) - actuvates guanylate cyclase --> increase in cGMP, LT (heat labile) - inactivated at higher temps - activates adenylate cyclase, increases cAMP(similar to cholera toxin)
Watery diarrheacholera or ETEC (traveler's)
Shiga toxin and shiga like toxin (EHEC) mechanisminhibit 60s subunit
Fever, anemia, thrombocytopenia, uremiaHUS, common with EHEC
Undercooked hamburger meat --> Bloody diarrhea/crampingEHEC
Fever, WBCs in stool, bloody diarrhea, crampsEIEC
Most common cause of UTIE coli
3 causes of meningitis in neonatesGroup B strep, E coli, listeria
Ecoli strains that cause neonatal meningitis have which antigen? How does this help the organism?K1 capsule that allows it to survive in bloodstream and establish meningeal infection
Nosocomial sepsis (2) organismsE coli, klebsiella pneumoniae
Alcoholic patients, aspiration pneumoniakelbsiella pneumonia
currant red jelly sputumklebsiella pneumonia
Alkaline urine, UTIproteus mirabilis. Has urease socleaves ammonia/CO2
Staghorn calculiproteus mirabilis - think of the stag patronus from harry potter!
Weil felix testuses proteus to determine if somebody has rickettsial infection because of its cross reactivity
Preschools, nursing home, bloody diarrheaShigella
Typoid feversalmonella typhi
Osteomyelitis in sickle cell patientssalmonella
Two most likely causes of osteomyelitis in patients with sickle cellsalmonella and S aureus
Vi antigencapsule for salmonella that protects it from opsonization and phagocytosis
Typhoid fever treatmentciprofloxacin or ceftriaxone
Pseudoappendicitisyersinia enterocolitica
Cholera toxin causes up regulation ofcAMP and therefore NaCl secretion in lumen
Vibrio cholerae is very sensitive togastric acidity
Antacid use/any condition that decreases acidity has what effect on vibrio cholera?lowers minimum infectious dose by a TON
Comma shaped organsimVibrio cholera
High alkaline media growthcholera
Thiosulfate-citrate-bile salt-sucrose agarvibrio cholera. This is the selective high alkaline medium it can grow on
Three leading causes of gastroenteritis in childrenCampylobacter jejuni, rotavirus, ETEC
Unpastteurized milkcampylobacter jejuni or listeria
Development of guillain barre syndromecampylobacter jejuni
Transmission of gastroenteritis (diarrhea mainly) from domestic animals (cattle, chicken, dogs) to humanscampylobacter jejuni
Ascending paralysis following gastroenteritisguillan barre after compylobacter jejuni infection
Duodenal ulcers, 2nd leading cause of GU as wellH pylori
IV drug users, right heart valve endocarditisStaph aureus - tricuspid valve murmur
Blue green, smells like grapespseudomonas aeruginosa
Burnspseudomonas aeruginosa
Pneumonia in CF patients, ventillator dependent patients and immunocompromisedpseudomonas aeruginosa
Otitis Media in diabetic patientspseudomonas aeruginosa
Pyelonephritis in immunocompromisedpseudomonas aeruginosa
When you see immunocompromised, first think of this bugpseudomonas aeruginosa
What is Ecthyma gangrenosum and what organism causes it?Necrotic cutaneous disease occurring with bacteremia/septicemia caused by pseudomonas aeruginosa. Common in immunocompromised patients (hospitalized, chemo, chronic indwelling catheters, burned victims etc)
Bacteroides fragilis normally lives inintestine
What causes bactericides fragilis to form abscesses?ruptures in intestine - trauma, iatrogenic, apendicitis, ischemia
Intraabdominal infections are polymicrobial. which two organisms are most prominent in these infections?B fragilis and E coli
H flu species usually acquired throughlungs
Hib (H flu type b) vaccine is againstprotein capsule
Haemophilus influenzae vaccine is conjugated to _____ to increased immunogenicitytetanus or diphtheria toxoid
EpiglottitisH flu
Haemophilus ducreyichancroid
Gonorrhea treatmentCeftriaxone + azitrho/doxy for chlamydia if its sexually transmitted
Clue cellsBV - gardener vaginalis
Stages of bordetella pertussiscatarrhal stage ensues (low-grade fever, runny nose, cough, sneezing), followed by the paroxysmal stage characterized by several episodes per day of violent coughing followed by an inspiratory “whoop” (gasp of air through a narrowed epiglottis).
Bordatella toxin effectdestroys ciliated epithelium along trachea/bronchial
Must swab this with calcium alginate because this organism won't grow on cottonBordatella pertussis
Bordet-Gengou mediumB pertussis - remember Bordet and bordetella
Household contacts bordetella pertussis preventionerythro or azithro
Pontiac feverlegionella
air condition units, whirlpools, mist machineslegionella pneumonphila
Very high fever in a smoker + diarrhea, confusion, and coughLegionella!
Fever, fatigue, chills, muscle aches, self resolving in one weekpontiac fever, legionella pneumonphila
High fevers, lobar consolidative pneumonia, low heart fate, elevated liver enzymeslegionella pneumonphila
legionella pneumonphila causes typical or atypical pneumonia?atypical
atypical pneumonias caused bylegionella pneumonphila, chlamydia psittaci, mycoplasma
Buffered charcoal yeast extract medium with L cystine + IronLegionella pneumonphilia
Animal bitespasteurella
Should you close animal bite wound? How should you treat?NO, penicillin or doxy

Pleomorphic bacteria

Question Answer
Elementary body, reticulate bodyForms of chlamydia. Elementary are metabolically inert but very small and infectious and go into cell/destroy lysosomes/grow. Reticulate bodies make own proteins but need host ATP
Trachoma - what is it and how do you treat it?chlamydia trachomatis - chronic conjunctivitis in children. Treat with azithro
Reiter syndrome (what's the triad)?triad of inflammatory arthritis, urethritis, and conjunctivitis commonly caused by chlamydia
Lymphogranuloma venerumpainless genital ulcer that disappears and is followed by enlargement of inguinal lymph nodes bilaterally, caused by chlamydia
Weil Felix reactionrickettsia
Dog tick or wood tick bite --> fever, conjunctival redness, ascending rashrocky mountain spotted fever caused by rickettsia rickettsii
Where is rocky mountain spotted fever most common?south east US
Cat scratch diseasebartonella henselae
Fever, malaise, swollen lymph nodes following cat scratch/ bitebartonella henselae, cat scratch fever/disease
Q fevercoxiella burnetii
Bacilary angiomatosisCat scratch fever can cause this (bartonella henselae) in immunocompromised patients.
Red purple papular skin lesions with scratchesBacillary angiomatosis caused by cat scratch fever ( bartonella henselae)


Question Answer
Three spirochetes to knowtreponema palladium, borrelia burgdorferi, leptospira interrogates
question mark shapedleptospira
How do you view these?Dark field microscopy
Condyloma latawartlike lesions in moist areas like the groin, associated with secondary syphilis
Gummastertiary syphilis
Argyll robertson pupiltertiary syphilis, not reactive to light
Positive romberg, ataxia, loss of pain/temperature sensationtabes dorsalis associated with tertiary syphilis
Saber shins and weird molars in kids with saddle nosecongenital syphilis
Syphilis txpenicillin
Jarisch herxheimer reactionfevers/headaches due to pyrogenic toxin release by syphilis when being killed
Giemsa/wright stainsborrelia and rickettsia
Erythema chronic migransbullseye rash with lyme
How do you treat early lyme? late?penicillin/doxy, ceftriaxone for late
Red conjunctiva, photophobialeptospirosis
animal urineleptospira


Question Answer
Beta lactams includepenicillins (penicillin, aminopenicillins, penicillinase resistant penicillins, antipseudomonal penicillins), cephalosporins, monobactams, carbapenems
What are the penicillins and what do they cover?Penicillin G and Penicillin V (oral) - cover Gram positive, actinomyces, and syphilis
What are the aminopenicillins and what do they cover?Ampicillin and amoxicillin - same as penicillin + some gram negative rods (H flu, coli, listeria monocytogenes, proteus marbles, salmonella, and enterococcus)
What side effect of amox happens when you give it to someone with EBV?bad rash
what are the penicillinase resistant penicillins? what are they used for?Methicillin, nafcillin, oxacillin, cloxacillin,dicloxacillin. Coverage for penicillin + MSSA - methicillin sensitive staph aureus
What are the antipseudomnal penicillins? What do they cover?Ticarcillin, Piperacillin, Carbenicillin. Same as penicillin + pseudomonas aeruginosa and anaerobes such as bactericides fragilis
What are the antipseudomonal cephalosporins?Ceftazidime, cefoperazone (both third generation) and Cefepime (4th generation)
What is a disfulam like reaction? What do you get it with?flushing, accelerated HR, shortness of breath, N/V - symptoms of a hangover essentially when you drink when you're on cephalosporins
Aztreonam coverage. Who are they used in?Gram negative aerobic bacteria only. Used in penicillin allergy people who can't tolerate B lactic antibiotics or patients with renal insufficiency who can't tolerate aminoglycosides
What are the "anti ribosomal antibiotics"?30s - Amingoglycosides, tetracyclines, 50s - chloramphenicol, clindamycin, erythromycin (and other macrolides), lincomycin, linezolid
How do aminoglycosides work?prevent formation of initiation complex at 30s subunit
What are the aminoglycosides? What do they cover?gentamicin, streptomycin, neomycin. Gram negative aerobic bacteria
How do tetracyclines work?Prevent aminoacyl-tRNA binding to ribosome-RNA complex
How do macrolides work?bind to 23s rNA of 50s subunit and block translocation/inhibit protein synthesis
What do macrolides act on?legionella, mycoplasma, chlamydia, and strep
How does rifampin work?inhibits DNA dependent RNA polymerase
Rifampin is used as prophylaxis following exposure toN meningitides or H influenzae
Treatment for TBRifampin, isoniazid, pyrazinamide, ethambutol ( RIPE)