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Microbiology - Systems

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eesohbel's version from 2015-08-03 22:05

Bugs Causing Food Poisoning

Question Answer
VibrioContaminated seafood (also can cause wound infections)
Bacillus cereusreheated rice iso
Staph aureusMeats, mayonnaise, custard
(preformed toxin)
Clostridium perfringensReheated meat dishes
C. botulinumImproperly canned foods (bulging cans), raw honey
E. coli 0157:H7Undercooked meat
SalmonellaPoultry, meat, eggs
campylobacterpoultry
what bug can be transmitted from domestic animals to humanscampylobacter
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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
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)
rotaviruswatery
noroviruswatery
adenoviruswatery
no erythrocytes or leukocytes in stoolcholera and E. Coli
mucus and sloughed epithelial cellscholera and E. Coli
hemorrhagic enteritis, rose spots on chest/abdomen, escalating feversalmonella typhi
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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, pseudomonas
enteric gram-negative rods
ImmunocompromisedStaphylococcus
enteric gram-negative rods
fungi
viruses
Pneumocystic jirovecii (with HIV)
AspirationAnaerobes (ex. Fusobacterciurm, Bacterorides, Peptostreptococcus, Prevotella)
Alcoholic/IV drug userStrep. pneumoniae
Klebsiella
Staphylococcus
CFPseudomonas
S. aureus
Strep. pneumoniae
PostviralStaph
H. influenzae
Strep. pneumoniae
AtypicalMycoplasma
Legionella
Chlamydia
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More on pneumonia

Question Answer
cavitary lesionaspergillus
interstitial patternatypical pneumonia
lobar pneumoniaklebsiella
currant jelly sputumklebsiella
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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 (greater than 250)
Dec. glucose
Fungal/TBInc. opening pressure
Inc. lymphocytes
Inc. proteins
Dec. glucose
ViralNormal/inc. opening pressure
Inc. lymphocytes
Normal/inc. protein (less than 150)
Normal glucose
neutrophilsbacterial meningitis
normal opening pressureviral meningitis
normal glucoseviral meningitis
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Causes of Osteomyelitis

Question Answer
If no other info is givenStaph A
Sexually activeSeptic arthritis
N. gonorrhoaeae (rare)
IV drug usersPseudomonas aeruginosa
Candida, s. aureus
Sickle cellSalmonella and S. Aureus
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
Positive leukocyte esterasebacterial
Positive nitrite testgram-negative bacteria (ex. E coli)
Positive ureaseproteus, klebsiella
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

Question Answer
chorioretinitis, hydrocephalus, intracanial calcifications, and or blueberry muffin rashtoxo
PDA, cataracts deafness and/or blueberry muffin rashrubella
hearing loss, seizures, petechial rach, periventricular calcifications and blueberry muffin rashCMV
encephalitisHSV-2
CNVIII deafness, facial abnormalititessyphillitis
what do you give to an HIV positive women during pregnancy to reduce transmissionHAART, intrapartum AZT, c-section, avoid breast feeding
neonatal encephalitis acquired howtypically through the birth canal. usually involves temporal lobes
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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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Nosocomial infections

Question Answer
CMV, RSVNewborn nursery
E.coli, Proteus mirabilisurinary cath
2 MCC of nosocomial infectionsE.coli (UTI)
Staph a (wound)
Pseudomonas aeruginosaVentilator
HBVWork in renal dialysis unit - at risk
Candida albicansHyperalimentation (IV feeding)
LegionellaWater aerosols
renal dialysis unit, needlestickHBV
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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. Thumbprint sign on x-ray
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Bug hints (if all else fails)

Question Answer
asplenic patientSHiN
branching rods in oral infections, sulfur granulesactinomyces
CGDcatalase positive microbes, especially staph aureus
"currant jelly" sputumklebsiella
dog or cat bitepasteurella
facial nerve palsylyme disease
fungal infection in diabetic or immunocompromised patientmucor or rhizopus
health care providerHBV
neutropenic patientscandida or aspergillus
organ transplantCMV
PAS positiveT. Whipplei
pediatric infectionH. Flu
pneumonia in cystic fibrosisburn infection
pus, empyema, abscesss. aureus
rash on hands and feetCocksackie A, Treponema pallidum, R. rickettsii
surgical wounds. aureus
traumatic open woundc. perfringens
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