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Microbiology - Systems

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usmlevan's version from 2015-04-23 05:21

Bugs Causing Food Poisoning

Question Answer
VibrioContaminated seafood (also can cause wound infections:V.vulnificus-->shellfish,water)
Bacillus cereusreheated rice
Staph aureusMeats, mayonnaise, custard
(preformed toxin)
Clostridium perfringensReheated meat dishes
C. botulinumImproperly canned foods (bulging cans)
E. coli 0157:H7Undercooked meat
SalmonellaPoultry, meat, eggs
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Bugs that can mimic appendicitis

Question Answer
Bugs that can mimic appendicitisYersinia enterocolitica
nontyphoidal Salmonella
Camplyobacter jejuni
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Bugs causing diarrhea

Question Answer
CampylobacterBloody
Comma or S-shaped organisms
growth at 42°C
SalmonellaBloody
Lactose negative
Flagellar motility
Has animal reservoir, especially poultry and eggs
ShigellaBloody
Lactose negative
very low ID50 (dose that will infect 50%)
produces shiga toxin (human reservoir only)
Enterohemorrhagic E. coli (EHEC)Bloody
0157:H7
can cause HUS
makes Shig-like toxin
Enteroinvasive E. coliBloody
Invades colonic mucosa
Yersinia enterocoliticaBloody
Day-care outbreaks
pseudoappendicitis
Entamoeba histolyticaBloody,liver abscess
protozoan
Enterotoxigenic E. coliWater
Traveler's diarrhea
Produces ST and LT toxins
Vibrio choleraeWatery
Comma-shaped organisms
rice-water diarrhea
C. difficileWatery or bloody
Pseudomembranous colitis
C. perfringensWatery
Also causes gas gangrene
ProtozoaWatery
Giardia
Cryptosporidium (in immunocompromised)
VirusesWatery
Rotavirus
Norovirus
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Common causes of pneumonia

Question Answer
Neonates (under 4 weeks)Group B strep
E coli
Children (4 wks-18 yrs)Runts May Cough Chunky Sputum
RSV (viruses)
Mycoplasma
Chlamydia trachomatis (infants - 3 yrs)
C. pneumoniae (school-aged)
Streptococcus pneumoniae
Adults (18-40 yrs)Mycoplasma
C. pneumoniae
S. pneumoniae
Adults (40-65 yrs)S. pneumoniae
H. influenzae
Anaerobes
Viruses
Mycoplasma
ElderlyS. pneumoniae
Influenza virus
Anaerobes
H. influenzae
Gram-negative rods
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Special groups (pneumonia)

Question Answer
NosocomialStaphylococcus
enteric gram-negative rods
pseudomona
ImmunocompromisedStaphylococcus
enteric gram-negative rods
fungi
viruses
Pneumocystic jirovecii (with HIV)
AspirationAnaerobes
Alcoholic/IV drug userStrep. pneumoniae
Klebsiella
Staphylococcus
CFPseudomonas
S. aureus
Strep. pneumoniae
PostviralStaph
H. influenzae
Strep. pneumoniae
AtypicalMycoplasma
Legionella
Chlamydia
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Common causes of Meningitis

Question Answer
Newborn (0-6 months)Group B strep
E. coli
Listeria
Children (6 Mo - 6 yrs)Strep. pneumoniae
Neisseria meningitidis
H. influenza type B
Enteroviruses
6-60 y/oStrep pneumoniae
N. meningitidis (#1 in teens)
Enteroviruses
HSV
60+ yrsStrep pneumoniae
Gram-negative rods
Listeria
Tx of meningitisceftriaxone and vancomycin empirically
add ampicillin if Listeria is suspected
Viral causes of meningitisenteroviruses (esp. coxsackie)
HSV-2 (HSV-1 = encephalitis)
HIV
West Nile
VZV
HIV - meningitisCryptococcus
CMV
Toxoplasmosis (brain abscess)
JC virus (demyelination)
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CSF findings in meningitis

Question Answer
Bacterialinc. opening pressure
inc. PMNs
Inc. protein
Dec. glucose
Fungal/TBInc. opening pressure
Inc. lymphocytes
Inc. proteins
Dec. glucose
ViralNormal/inc. opening pressure
Inc. lymphocytes
Normal/inc. protein
Normal glucose
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Causes of Osteomyelitis

Question Answer
If no other info is givenStaph A
Sexually activeSeptic arthritis more common
N. gonorrhoaeae (rare)
Diabetics and IV drug usersPseudomonas aeruginosa
Serratia
Sickle cellSalmonella
Prosthetic replacementS. aureus
Staph epidermidis
Vertebral diseaseMycobacterium tuberculosis (Pott's disease)
Cat and dog bites or scratchesPasteurella mulocida
Classic labs in osteomyelitisElevated CRP and ESR (not specific)
in children
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UTI bugs

Question Answer
UTI testsPositive leukocyte esterase test → bacterial
Positive nitrite test → gram-negative bacterial
Positive urease test → proteus, klebsiella
Negative Urease test → E. coli, Enterococcus
Leading cause of UTI
Colonies show green on EMB agar
E. Coli
2nd leading cause of community-acquired UTI (sex-active women)Staph saprophyticus
3rd leading cause of UTI
Large mucoid capsule and viscous colonies
Klebsiella pneumoniae
Red pigment
often nosocomial and drug resistant
Serratia marcescens
Often nosocomial and drug resistantEnterobacter cloacae
Motility causes "swarming" on agar
Produces urease
Associated with struvite stones
Proteus mirabilis
Blue-green pigment and fruity odor
usually nosocomial and drug resistant
Pseudomonas aeruginosa
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ToRCHeS infections

AgentTransmissionMaternal manifestationsNeonatal manifestations
Toxoplasma gondiicat feces or ingestion of undercooked meatusually asymptomatic:mom has lymphadenopathychorioretinitis, hydrocephalus, intracranial calcifications
RubellaRespiratory dropletsmom has rash (face, trunk, limbs - 3 days long), lyphadenopathy, arthritisPDA or pulm artery hypoplasia, cataracts, deafness. may have bluberry muffin rash
CMVSexual contact, organ transplantsmom has a mono like illnesshearing loss, seizures, petechial/"blueberry muffin" rash
HIVSexual contact, needlestickmom has many possible infections assoc w/low CD4 countrecurrent infections, chronic diarrhea
HSV-2Skin or mucous membrane contactusually asymptomatic:mom has a vesiculo pustular lesionencephalitis, herpetic (vesicular) lesions
SyphilisSexual contactmom has a chancre, hand foot rashstillbirth, hydrops, facial abnormalities (notched teeth, saddle nose with hemorrhagic rhinitis, short maxilla, yellow-brown hue), saber shins, CNVIII deafness,rhagades:linear scars at angle of mouth
ParvovirusContactLace-like, reticular rashhydrops fetalis b/c of B19 .... not really a torch, but whatevs
Nonspecific signs of many ToRCHeS infectionshepatosplenomegaly, jaundice, thrombocytopenia, growth retardation..
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Red Rashes of Childhood

Question Answer
Rubella virusTogavirus
Rash: begins at head → moves down into fine truncal rash - lasts 3 days
Postauricular lymphadenopathy
MeaslesA paramyxovirus
Rash begins at head and moves down
Rash preceded by cough, coryza, conjunctivitis, blue-white (Koplik) spots on buccal mucosa
VZVChickenpox
Vesicular rash begins on trunk → spreads to face and extremities with lesions of different ages
HHV-6Roseola
Macular rash all over body after several days of high fever
can present with febrile seizures
usually affects infants
Parvovirus B19Erythema infectiosum
"Slapped cheek" rash on face
Can cause hydrops fetalis in pregnant women
Strep pyogenesScarlet fever
Erythematous, sandpaper-like rash with fever and sore throat
Coxsackievirus type APicornavirus
Hand-foot-mouth disease
Vesicular rash on palms and soles
Ulcers in oral mucosa
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STDs

Question Answer Column 3
GonorrheaUreth/Cervicitis, PIC, prostatitis, epididymitis, creamy purulent discharge
arthritis
Neisseria gonorrhoeae
1° syphilispainless chancreTreponema pallidum
2° syphilisFever, lymphadenopathy, skin rashes, condylomata lata (wart-like lesion)Treponema pallidum
3° syphilisGummas (in liver, heart or other tissue - can cause heart valve disorder), tabes dorsalis, general paresis, aortitis, Argyll Robertson pupiltreponema pallidum
ChancroidPainful genital ulcer
inguinal adenopathy
Haemophilus ducreyi (PAINFUL → do cry)
Genital herpesPainful penile, vulvar, or cervical vesicles & ulcers
fever, headache, myalgia
HSV-2 (less HSV-1)
ChlamydiaUrethritis, cervicitis
conjunctivitis
Reiter's syndrome
PID (subacute)
Cervical motion tenderness (chandelier sign)
Chlamydia trachomatis (D-K)
Lymphogranuloma venereumInfection of lymphatics
painless Genital ulcers
painful lymphadenopathy
rectal strictures
Chlamydia trachomatis (L1-L3)
TrichomoniasisVaginitis, strawberry cervix & mucosa
motile in wet prep
Trichomonas vaginalis
AIDSOpportunistic infections
Karposi's sarcoma
Lymphoma
HIV
Condylomata acuminataGenital warts
Koilocytes
HPV-6,11
Hepatitis BJaundiceHBV
Bacterial vaginosisnoninflammatory, malodorous discharge (fishy smell)
positive whiff test, clue cells
Gardnerella vaginalis
PID - MC bugsChlamydia (subacute, often undiagnosed)
N. gonorrhoeae (acute)
Fitz-Hugh-Curtis syndromechlamydia
infection of the liver capsule and "violin string" adhesions of parietal peritoneum to liver=perihepatitis
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Nosocomial infections

Question Answer
CMV, RSVNewborn nursery
E.coli, Proteus mirabilisurinary cath
2 MCC of nosocomial infectionsE.coli (UTI)
Staph a (wound)
Pseudomonas aeruginosaVentilator,respiratory therapy equip
HBVWork in renal dialysis unit - at risk
Candida albicansHyperalimentation (IV feeding)
LegionellaWater aerosols
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Bugs affecting unimmunized kids

Question Answer
RashRubella - head→down w. postauricular lymphadenopathy
Measles - head→down w preceding cough, coryza, conjunctivitis, Koplik spots on buccal mucosa
MeningitisH. influenza type B - microbe colonizes nasopharynx
Poliovirus - also myalgias and paralysis
PharyngitisCorynebacterium diphtheriae - gray throat - toxin causes necrosis in pharynx, cardiac, and CNS tissue
EpiglottitisH. influenzae type B - fever w dysphagia, drooling, and difficulty breathing d/t edematous "cherry red" epiglottis
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Bug hints (if all else fails)

Question Answer
Pus, empyema, abcessStaph aureus
Pediatric infectionH. influenzae (incl. epiglottitis)
Pneumonia in CF, burn infectionPseudomonas aeruginosa
Branching rods in oral infection, sulfur granulesActinomyces israelii
Traumatic open woundClostridium perfringens
Surgical woundStaph aureus
Dog or cat bitePasteurella multocida
"Currant jelly" sputumKlebsiella
Positive PAS stainTropheryma whipplei
Sepsis/meningitis in newbornGroup B strep
Heath care providerHBV (From needle stick)
Fungal infection in diabetic or immunocomp. personMucor or Rhizopus spp.
Asplenic ptEncapsulated microbes - SHiN (Strep pneumo, H. influ, N. meningitidis)
Chronic granulomatous diseaseCatalase-positive microbes, esp. Staph a
Neutropenic ptsCandida albicans (systemic)
Aspergillus
Facial nerve palsyBorrelia burgdorferi (Lyme disease)
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