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Clinical bacteriology Flashcards

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1
Q

Gram positives

A

Can make exotoxins
Cocci
- Catalase pos (clusters) –> staph
- Catalase neg (chains) –> strep

Rods (bacilli)

  • Clostridium
  • Corynebacterium
  • Listeria
  • Bacillus
  • Mycobacterium

Branching enzymes

  • Anaerobe - not acid fast = actinomyces
  • Aerobe - acid fast = nocardia
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2
Q

Catalase positive cocci

A

Clusters, staphylococcus; coagulase pos or neg

  • Coagulase pos = S. aureus
  • Coagulase neg = S. epidermidis, S. saprophyticus

“NO StRESs
- Novobiocin - Saphrophyticus Resistant; Epidermidis Sensitive

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3
Q

Catalase negative cocci

A

Chains, steptococcus –> get a, B, gamma hemolytic bacteria

“OVRPS” (overpass) <– B-hemolytic
- Bacitracin - group B strep Resistant; group A sensitive

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4
Q

a-hemolytic bacteria

A

Partial hemolysis; form green ring around colonies on blood agar

  • Viridans - no capsule, catalase neg, optochin resistant, not lysed by bile
  • S. pneumoniae - has capsule, catalase neg, optochin sensitive

“OVRPS”

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5
Q

B-hemolytic bacteria

A

Complete hemolysis; clear ring around colonies on blood agar

  • S. aureus - catalase and coagulase +
  • Group A strep (strep pyogenes) - catalase neg, bacitracin sensitive
  • Group B strep (strep agalactiae) - catalase neg, bacitracin resistant

“B-BRAS”

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6
Q

Staph aureus

A

Gram positive, clusters (catalase +)
- Protein A virulence factor - binds Fc of IgG –> inhibit complement activation/phagocytosis

Skin infections, toxin-mediated disease, MRSA

Toxin mediated:

  • S. aureus food poisoning = ingestion of preformed enterotoxin (heat-stable), short incub (2-6hr)
  • TSST - binds MHCII/T-cell receptor, get polyclonal T-cell activation –> fever, rash, vom, shock, death
  • SSSS (scalded skin syndr) - makes exfoliative exotonin (+Niklosky sign)

Coagulase + = bad bc makes fibrinogen –> fibrin, coats bacteria and protects from phagocytosis

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7
Q

Staph epidermidis

A

Biofilms –> infects prosthetic devices/catheters
- Catalase negative, novobiocin sensitive

“NO StRES”

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8
Q

Staph saphrophyticus

A

2ns most common uncomplicated UTI in women (#1 = E. coli)
- Catalase negative, novobiocin resistant

“NO StRES”

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9
Q

Streptococcus pneumoniae

A

S. pneumoniae, lancet-shaped gram +s
- a-hemolytic, encapsulated, IgA protease, optochin sensitive

  • Causes MOPS = meningitis, otitis media, pneumonia, sinusitis
  • Pneumococcus - rusty colored sputum, sepsis in sickle cell anemia/spenectomy
  • If remove capsule, no virulence)

“MOPS are MostOPtochin Sensitive”

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10
Q

Viridans group strep

A

*Make dextrans from sucrose - help adhere to surfances (tooth caries, heart valves)

S. mutans (carries), S. sanguinis (endocarditis at damaged valves)
- a-hemolytic (partial), no capsule, optochin resistant

  • S. sanguinis makes dextrans (bind fibrin-plt aggregates on damaged valves)
  • Why we give abx before dental procedures in pts w/ heart valves
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11
Q

Strep pyogenes

A

Group A strep, B-hemolytic (catalase neg)

  • Pyogenic - pharyngitis, cellulitis, impetigo
  • Toxigenic - scarlet fever, TS-like syndrome, nec fasciitis
  • Immunologic - rheumatic fever (Jones criteria), acute glomerulonephritis

Pharyngitis can cause rheumatic “phever” and glomerulonephritis
- Impetigo - more before glomerulonephritis than pharyngitis

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12
Q

Strep agalactiae

A

Group B strep, colonizes vagina, B-hemolytic (catalase neg)

  • Pneumonia, meningitis, sepsis in Babies
  • Makes CAMP which incr hemolysis from s. aureus (Hippurate test +)
  • Screen pregnant women at 35-37 wks, if positive tx intrapartum w/ penicillin

“Group B for Babies!”

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13
Q

JONES criteria

A

Rheumatic fever (from s. pyogenes):

  • Joints - polyarthrtis
  • <3 - carditis
  • Nodules - subcutaneous
  • Erythema marginatum
  • Sydenham chorea
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14
Q

Scarlet fever

A

From S. pyogenes:

  • Scarlet rash (sandpaper texture)
  • Strawberry tongue
  • Circumoral pallor
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15
Q

Enterococci

A

Group D strep (E. faecalis), no hemolysis

  • Grows in bile/acidic env (nl in GI/GU)
  • VRE = vanc resistant enterococci –> cause nosocomial infection
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16
Q

Strep bovis

A

Group D strep, colonizes gut
- Bacteremia + acute endocarditis in colon cancer pts

“Bovis in Blood = Cancer in the Colon”

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17
Q

Rods

A

Bacilli

  • Clostridium
  • Corynebacterium
  • Listeria
  • Bacillus
  • Mycobacterium
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18
Q

Corynebacterium diptheriae

A

Causes diptheria - via endotoxin (from B-prophage)

  • Endotoxic inhibits protein synthesis (inhibit ADP-ribosylation of EF2)
  • Sx: pseudomembranes (gray-white membrane), lymphadenopathy, myocarditis, neuro toxicity (toxin penetrates blood:brain)
  • Dx - gram + with metachromatic (blue/red) granules + Elek test for toxin
  • Prevention - toxoid vaccine

“ABCDEFG” - ADP ribosylation, B-prophage, Corynebacterium, Diptheriae, EF2, Granules

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19
Q

Bacterial spores

A

Some bacteria make spores when nutrients limited

  • Spores = heat/chemical resistant
  • Must autoclave to kill spores (121C for 15min)*
  • Dipicolinic acid = core, no metab activity

Causing spores:

  • Soil - bacillus anthracis, Clostridium perfringens, C. tetani
  • Other: B. cereus, C. botulinum, Coxiella burnetii
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20
Q

Clostridia types

A

Gram positive, spore-forming, obligate anaerobic bacilli

  • C. tetani
  • C. botulinum
  • C. perfringens
  • C. difficile
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21
Q

C. tetani

A

Exotoxin = tetaniospasmin

  • Protease - cleaves release proteins for NTs
  • Blocks glycine/GABA release (inhib NTs) from Renshaw cells in spinal cord
  • Spastic paralysis, trismus (lockjaw), risus sardonicus (grin)
  • Vaccine = inactivated tetanus toxin
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22
Q

C. botulinum

A

Exotoxin = botulinum toxin –> preformed, heat-labile

  • Protease - cleaves release proteins for NTs
  • Inhibits ACh release at NMJ
  • Adults - eat preformed toxin (canned food, good anaerobic env)
  • Babies - eat spores in honey = floppy baby syndrome
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23
Q

C. perfringens

A

Toxin = a-toxin (lecithinase = phospholipase)

  • Causes myonecrosis (gas gangrene) and hemolysis
  • Myonecrosis from plt aggregation, adherance molecules, vasoocclusion + necrosis
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24
Q

C. difficile

A

Toxin A = enterotoxin, binds brush border of gut
Toxin B = cytotoxin - pseudomembranous colitis, diarrhea
- Secondary to abx use (amp/clinda)
- Dx - toxins in stool
- Tx = metranidazole or oral vanc

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25
Q

Anthrax

A

Bacillus anthracis - spore-forming rod, makes anthrax toxin
- Only bacteria w/ polypeptide capsule (D-glutamate)

Cutaneous anthrax - boil lesions, painless + become necrotis [rarely progresses]

Pulmonary anthrax - Inhalation of spores, flu-like –> fever –> pulm hemorrhage –> mediastinitis –> shock
*Woolsorter’s disease - inhaled from contaminated wool

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26
Q

Bacillus cereus

A

Food poisoning, spores survive cooked rice

  • Emetic type:
  • Cereulide = preformed toxin, get w/ rice or pasta, n/v in 1-5 hrs
  • Diarrheal type:
  • Watery, non-bloody diarrhea + GI pain, 8-18hr

Reheated rice syndrome

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27
Q

Listeria monocytogenesis

A

Facilitative INTRACELLULAR microbe

  • Rocket-tails (actin polym) allow them to move in cytoplasm to cell membrane (avoid Ab); tumbling motility
  • *Make LPS (only gram + to do this!)
  • *Narrow B-hemolytic, replicate at refrig temp (refrig food)
  • Ingesting unpasteurized dairy/deli meat, transplacental or vaginal at birth
  • Baby: amnionitis, septicemia, spont abortion, granulomatosis, meningitis
  • Immunocompromised - meningitis
  • Healthy - mild GI disease

Tx - GI = self-limited
- Ampicillin - empiric meningitis tx (babies, immunocompromised, elderly)

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28
Q

Branching filaments

A

Both gram positive

  • Actinomyces - not acid fast, in normal oral flora, get oral/facial abscesses with draining yellow “sulfur granules”
  • A. israelii = actinomyces, yellow sand in israel
  • Nocardia - acid fast, in soil, get pulm infections in immunocompromised
  • Tx = sulfonamides
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29
Q

Mycobacteria

A

All are acid-fast organisms

  • Mycobacterium TB = TB
  • M. kansasii - pulm, TB-like sx (water contaminant of municipal H2O system, not nature)
  • M. avium-intracellulare (disseminated non-TB in AIDS) –> ppx = azithromycin
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30
Q

TB

A

Primary - Ghon focus (mid lung)

  • Heal by fibrosis - immunity/hypersensitivity –> tuberculin +
  • Progressive lung disease (in HIV, malnutrition) = rare
  • Severe bacteremia = miliary TB = death
  • Preallergic lymphatic/hematogenous dissemination –> dormant tubercle bacilli in organs –> reactivation later

Secondary TB - reinfected, fibrous caseating granulomas (upper lobes)

  • See w/ reactivation of TB of lunds
  • Extrapulm TB - CNS (tuberculoma or meningitis), vertebral body (Pott)
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31
Q

PPD reading

A
  • PPD pos if current infection, past exposure or BCG vaccine
  • PPD neg if no infection, anergic (steroid, malnutrition, immunocompromised), or sarcoid
  • TH1-cell mediated delayed hypersensitivity response
  • IFN-gamma release assay has fewer false + (esp BCG vaccine)
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32
Q

TB vs. sarcoidosis

A 
TB = caseating granulomas
Sarcoidosis = non-caseating granulomas
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33
Q

Leprosy

A

Hansen disease; from mycobacterium leprae

  • Acid-fast bacillus
  • Likes cool temperatures, infects skin/superficial nerves (“glove + stocking” sensation loss)
  • Can’t grow in vitro
  • Reservoir = US armadillos

Lepromatous form - diffusely on skin, leonine facies (lion-like), communicable

  • Low cell-mediated immunity (humoral TH2 response)
  • Tx = dapsone, rifampin, clofazimine 2-5 yrs

Tuberculoid form - hairless plaques

  • High cell-mediated immunity (largely TH1 response)
  • Tx = dapsone + rifampin x6mo
34
Q

Gram negative bacteria

A
  • Diplococci
  • Coccoid rods
  • Rods - lactose fermenter vs. lactose non-fermenter
  • Oxidase +, comma shaped
35
Q

Penicillin and gram negatives

A

Gram negatives resistant to penicillin G/vanc!

  • May be susceptible to derivatives (ampicillin, amoxicillin)
  • Outer membrane layer inhibits entry of penicillin and vancomycin
36
Q

Diplococci

A

Gram negative bacteria:

  • Neisseria meningitidis
  • Neisseria gonorrhoeae
  • Both make IgA protease
37
Q

Neisseria gonorrhoeae

A

Diplococci, gram negative bacteria, STD

  • No polysaccharide capsule
  • No maltose fermentation (ferment glucose)
  • No vaccine bc rapid pilus proteins
  • Sx: gonorrhea, septic arthritis, neonatal conjunctiv, PID/Fitz-Hugh-Curtis syndrome
  • Tx = ceftriaxone (+ azithro/doxy for chlamydia co-infection)

Opaque exudate, intracellular organisms (in neutrophils)

38
Q

Neisseria meningitidis

A

Diplococcia, gram negative bacteria

  • Polysaccharide capsule
  • Maltose and glucose fermentation
  • Vaccine (except type B)
  • Have in respiratory/oral secretions –> pili adhere to oral mucosa
  • Sx: meningococcemia (purpuric lesions, shock, death), meningitis, Waterhouse-fridrichsen syndrome (adrenal destroyed)
  • Tx: ceftriaxone or penicillin G
39
Q

“Coccoid” rods

A

Gram negative bacteria

  • H. influenzae
  • Pasteurella
  • Brucella
  • Bordetella pertussis
40
Q

Haemophilus influenza

A

Gram negative coccoid rod, aerosol transmission

  • H. influenza B (type B) = CAPSULE, most invasive
  • Makes IgA protease
  • Cx on chocolate agar w/ factors V and X for growth
  • Can grow with E. coli - provides factor V
  • Sx: haEMOPhilus - epiglottitis (cherry red), meningitis, otitis media, pneumonia
  • Tx mucosal - amoxicillin, clavulanate
  • Tx meningitis - ceftriaxone; rifampin ppx for contacts
41
Q

H. influenza B vaccine

A

Type B capsular polysaccharide conjugated to protein

- Give age 2-18 mos

42
Q

Rods

A

Lactose fermenter vs. nonfermenters

Lactose fermenters:

  • Fast fermenters: Klebsiella, E. coli, Enterobacter
  • Slow fermenters: Citrobacter, Serratia
  • Grows on “macConKEE’S agar”

Lactose non-fermenters

  • Oxidase + = pseudomonas
  • Oxidase neg = shigella, salmonella, yersinia, proteus
43
Q

E. coli

A 
Gram negative, lactose fast-fermenter
Virulence factors:
- Fimbriae - cystitis/pyelonephritis
- K capsule - pneumonia, neonatal meningitis
- LPS endotoxin - septic shock

EIEC - Invasive; dysentery
ETEC - Traveler’s diarrhea (watery)
EPEC - Pediatric diarrhea
EHEC - Hemolytic-uremic syndrome

44
Q

EIEC

A

Microbe invades intestinal mucosa –> necrosis and inflammation
- Presents similarly to shigella

45
Q

ETEC

A

Heat-labile (HL) and heat-stable (HS) enterotoxins
- No inflammation/invasion –> TOXIN mediated

*Travel’s diarrhea from enteroToxins

46
Q

EPEC

A

No toxin made - bacteria adheres to apical surface, flattens villi, prevents absorption in intestine
*Diarrhea usually Pediatric

47
Q

EHEC

A

Dysentery –> toxin alone causes necrosis/inflam
O157:H7 most common
- Shiga-like toxin, inactivate 60S subunit of ribosome, causes Hemolytic-uremic syndrome (anemia, thrombocytopenia, acute renal failure)
*aka STEC (shiga toxin-producing E. coli)
- Microthromi form on epithelium damaged by toxin –> mechanical hemolysis (schistocytes), decr renal blood flow
**Microthrombi also consume plts = thrombocytopenia (thrombi + thrombocytopenia)

*Doesn’t ferment sorbitol or make glucuronidase (all other E. coli do)

48
Q

Klebsiella

A

Gram negative, lactose fast-fermenter

  • Normal intestinal flora –> lobar-pneumonia in alcoholics/DM when aspirated
  • “Red currant jelly” sputum (=intusussception of mouth!)
  • Nosocomial UTIs too

4A’s: aspiration pneumonia, abscess in lung/liver, Alcoholics, diAbetics

49
Q

Shigella

A

Gram negative, lactose non-fermenter, oxidase neg

  • No flagella, cell-to-cell transmission (no hematogenous)
  • Humans/primates = only animal reservoir
  • Shiga toxin inactivates 60S
  • invades intestinal mucosa (binds mucosal M cells) –> PMN response; often causes bloody diarrhea
  • Doesn’t make hydrogen sulfide
  • Abx - shorten fecal excretion of organism
50
Q

Salmonella

A

Gram negative, lactose non-fermenter, oxidase neg

  • Flagella (“salmon swim”), can disseminate hematogenously
  • Animal reservoirs
  • Invades intestinal mucosa –> monocytic response; can cause bloody diarrhea
  • Makes hydrogen sulfide
  • Abx - prolong fecal excretion of organism
51
Q

Salmonella typhi

A

Typhoid fever, only in humans

  • Rose spots on abd, fever, HA, diarrhea
  • Can stay in gallbladder = carrier state
52
Q

Yersinia enterocolitica

A

Gram negative, lactose non-fermenter, oxidase neg

  • From pet feces (puppies), contaminated milk or pork
  • Sx - mesenteric adenitis, mimic Crohn’s/appendicitis
53
Q

Pseudomonas aeruginosa

A

Aerobic gram negative, lactose non-fermenter, oxidase positive

  • Makes pyocyanin –> blue-green pigment on cx, smells like grapes
  • Comes from contaminated water
  • Makes endotoxin (fever, shock) and endotoxin A (inactivates EF-2)
  • Sx: wound/burns + *PSEUDOmonas = pneumonia (CF, biofilm), sepsis, external otitis, UTI, Drug use, Diabetic Osteomyelitis, hot-tub folliculitis (papulopustular rash)
  • Tx: amingoglycoside + extended-spectrum penicillin

Ecthyma gangrenosum - necrotic cutaneous lesion, immunocompromised pts, from pseudomonas

  • Aeruginosa = Aerobic; water connection w/ blue-green pigment
  • contaminated water, burn victims, CF (chronic pneumo)
54
Q

Oxidase +, comma shaped gram neg

A
  • Campylobacter jejuni - grow at 42C
  • Vibrio cholerae - grow in alkaline environment
  • Heliobacter pylori - produce urease
55
Q

Campylobacter jejuni

A

Gram negative bacteria, comma/S shaped, oxidase +, grows at 42C (campylobacter by hot camp fire)

  • Fecal-oral (meats/unpasteurized milk, puppies)
  • 500 org for innoculation
  • Sx: blood diarrhea (esp in kids)
  • *Common cause of Guillain-Barre syndrome + reactive arthritis
56
Q

Vibrio cholerae

A

Gram negative bacteria, comma/S shaped, oxidase +, grows in alkaline media

  • Enterotoxin permanently activates Gs –> cAMP
  • Profuse rice-water diarrhea via enterotoxin
  • Endemic to dx countries; need prompt ORS
57
Q

Heliobacter pylori

A

Gram negative bacteria, curve shaped, oxidase, catalase +; produces urease

  • Risks: gastritis, PUD (esp duodenal), lymphoma, adenocarcinoma, SMOKING
  • Creates alkaline environment
  • Tx = triple therapy (PPI, clarithromycin, amox/metronidazole)

*Dx - urea breath test (urea producing) or fecal antigen test

58
Q

Legionella pneumophilia

A

Gram negative rod, need silver stain

  • Grow on charcoal yeast w/ iron/cysteine
  • Aerosol transmission from water source (A/C, hot tub) –> NO PERSON-TO-PERSON
  • Tx: macrolide (eryth/clarith/azithro) or quinolone

Legionnaire’s disease = severe pneumonia, fever, GI/CNS sxs
Think Legionella when pneumonia and GI!!!

“Legionnaire - silver helmet, sitting w/ charcoal and iron dagger

59
Q

Spirochetes

A

Spiral-shaped bacteria with axial filaments
BLT
- Borrelia (Big) <– dark field microscopy

60
Q

Borrelia

A

Spirochete; Lyme disease = borrelia burgdorferi
- Transmitted by tick Ixodes; reservoir = mice
Disease progr:
1) Early = flu-like, erythema chromicum migrans (Bull’s eye/target)
2) AV block, Bell’s palsy
3) Chronic asym jt arthritis, encephalopathy
- Tx: doxycycline or ceftriaxone (penicillin-type)

FAKE = facial n palsy, arthritis, kardiac block, erythema migrans

61
Q

Leptospira interrogans

A

Spirochete, found in water contaminated w/ animal urine

  • Sx - flu-like, jaundice, photophobia conjunctival suffusion (red, no exudate)
  • See in surfers in the tropics (Hawaii)

Weil disease - iscterohemorrhagic leptospirosis = severe form w/ jaundice + azotemia (liver/kidney disfxn)

62
Q

Treponema pallidum

A

Spirochete, causes syphilis

  • Primary - painless chancre
  • Secondary - disseminated, rash on palms/soles
  • Tertiary - gummas, neurosphyilis (tabes dorsalis), Argyll robertson pupil
  • Congenital

*VDRL/RPR = non-specific; FTA-ABS confirm

63
Q

Primary syphillis

A

Localized - painless chancre

- Use dark-field microscopy to see treponema from chancre

64
Q

Secondary syphillis

A

Disseminated - constitutional sx, maculopapular rash on hands/soles, condylomata lata

  • Confirm with dark-field microsc
  • Eventually get latent syphillis (w/o sxs)
65
Q

Tertiary syphillus

A

Gummas (chronic granulomas), aortitis (vasa vasorum destruction, weakened aorta w/ AA-not dissection), neurosyphilis (tabes dorsalis), argyll robertson pupil

  • Sx - broad-based ataxia, +Romberg, charcot join, stroke w/o HTN
  • Dx - spinal fluid w/ VDRL/RPR (neurosyph)
66
Q

Congenital syphilis

A

Saber shins, saddle nose, CN VIII deafness, Hutchinson teeth, mulberry molars
- Tx mom early (transmission after T1)

67
Q

Argyll Robertson pupil

A

Constricts with accomodation, but does not react to lifht
- Tertiary syphilis

“Prostitute pupil” - accomodates but doesn’t react

68
Q

VDRL False positives

A

Nonspecific, react with beef cardiolipin

- VDRL - viruses (mono, hepatitis), drugs, rheumatic fever, lupus/leprosy

69
Q

Jarisch-Herxheimer rxn

A

Flu-like syndrome after start abx bc of killed bacteria releasing pyrogens

70
Q

Gardnerella vaginalis

A

Pleomorphic gram-variable rod - vaginosis

  • Gray vaginal discharge, fishy smell
  • Associated with sexual activity (not STD)
  • Overgrowth of certain anaerobic bacteria in vagina
  • Microscopy - clue (vagina epithelial) cells covered in bacteria
  • Tx: metronidazole or clinda

“I have no CLUE why I smell FISH in the VAGINA GARDEN!”

71
Q

Rickettsial disease and vector-borne illness

A

Tx for all = DOXY!

Rash common: “Rickettsi on wRists, Typhus on Trunk”

  • Rocky Mountain spotty fever
  • Typhus

Rash rare:

  • Ehrlichiosis
  • Anaplasmosis
  • Q fever
72
Q

Rocky mountain spotted fever

A

Rickettsia rickettsii –> tick vector

  • South atlantic (NC)
  • Obligate intracellular organisms - need CoA/NAD+ (can’t make ATP)

Sx triad: HA, fever, rash

  • Rash starts on wrists/ankles –> spreads to trunk, palms, soles
  • Coxsackievirus A (hand/foot/mouth), RMSF, 2 syphillis –> all rashes w/ palms+soles
73
Q

Typhus

A

Endemic (fleas) –> R. typhi
Epidemic (human body louse) - R prowazekii
- Rash starts centrally, moves out; spares palms/soles

74
Q

Ehrlichiosis

A

Ehrlichia –> tick vector

- Monocyte w/ morulae (berry-like inclusion) in cytoplasm

75
Q

Anaplasmosis

A

Anasplasma –> tick vector

- Granulocyte with morulae in cytoplasm

76
Q

Q fever

A

Coxiella burnetii - no arthropod vector

  • Tick feces/cattle placenta release spores, inhale as aerosols
  • Sx = pneumonia

Q fever = Queer bc no arthropod vector, no rash –> survives outside endospore
- Related to rickettsia genus (not part)

77
Q

Chlamydiae

A

Obligate intracellular (cloak = chlamys) organisms

  • Elementary body - infectious, enters via endocytosis –> becomes reticulate body
  • Reticulate body - replicates in cell via fusion –> reorganize into elementary body
  • Cycle
  • Dx - cytoplasmic inclusions on Giemsa/fluorescent ab-stained smear
  • Tx - azithromycin or doxy
78
Q

Types of chlamydia

A
  • C. trachomatis
  • C. pneumoniae + C. psittaci - atypical pneumonia (aerosol = atypical transmission)
  • Psittaci = avian reservoir
79
Q

Chlamydia trachomatis

A
  • Sx - reactive arthritis (Reiter syndr), follicular conjunctivis, nongonococcal urethritis, PID

Type A,B,C - Africa, blindness, chronic infection

Types D-K - urethritis/PID, ectopic pregn, neonatal pneumonia (staccato cough), conjunctivitis
* D-K = everything else

Type L1,L2,L3 - lymphogranuloma verenum = small, painless ulcers on genitals –> swollen painful inguinal LNs that ulcerates (buboes)

80
Q

Myoplasma pneumoniae

A

No cell wall (sterols for stability), not seen on gram stain

Atypical “walking” pneumonia, pts <30yo

  • Insidious onset, HA, nonprod cough, patchy/diffuse interstitial infiltrates
  • XR looks worse than pt
  • Cold agglutinins (IgM) - can agglutinate or lyse RBCs
  • Often in military recruits/prisons*

Tx - macrolide, doxy, fluoroquinolone. Penicillin doesnt work bc no cell wall!

Microbiology (7 decks)

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