Microbiology Flashcards
Bug: Pus, empyema, abscess
S. aureus
Bug: Pediatric infection
H. influenza
Bug: PNA in CF or Burn patients
Pseudomonas aeruginosa
Bug: Branching rods in oral infection; sulfur granules
Actinomyces israelii
Bug: Traumatic open wound
C. perfringens
Bug: Surgical wound
S. aureus
Bug: Dog or cat bite
Pasturella multocida
Bug: Currant jelly sputum
Klebsiella
Bug: Positive PAS stain
Tropheryma whipplei (Whipple’s disease)
Bug: Sepsis/meningitis newborn
GBS
Bug: Health care provider needlestick
HBV
Bug: Fungal infection in DM or IC host
Mucor or Rhizopus
Bug: Asplenic patient
Encapsulated: S. pna, H. influenza B, N. meningitis
Bug: Chronic granulomatous disease
Catalase-positive: S. aureus
Bug: Facial nerve palsy
Borreilia burgdorferi (Lyme disease)
Nosocomial: newborn nursery
CMV, RSV
Nosocomial: urinary catheterization
E. coli, Proteus mirabilis
The 2 most common causes of nosocomial infection:
- E. coli (UTI)
2. S. aureus (wound infection)
Nosocomial: respiratory therapy equipment
Pseudomonas (with air or burns)
Nosocomial: working in a renal dialysis unit
HBV
Nosocomial: TPN
Candida albicans
Nosocomial: water aerosols
Legionella
Unimmunized child with rash:
- Head down with post-auricular LAD
- Head down preceded by cough, coryza, conjunctivitis w/ Koplik spots
- Rubella
2. Measles
Unimmunized child with meningitis
H. influenza B [colonizes nasopharynx]
Poliovirus [myalgia and paralysis]
Unimmunized child with pharyngitis
- Grayish OP exudate
- Cherry-red epiglottitis, difficulty breathing
- Corynebacterium diptheriae
2. H. influenza B
Peds: Vesicular rash on palms & soles; ulcers in oral mucosa
Coxsackie A “Hand-foot-mouth disease”
Peds: Erythematous, sandpaper-like rash with fever & sore-throat
S. pyogenes “Scarlet fever”
Peds: Slapped cheek rash on face (that can cause hydrops fetalis in pregnant women)
Parvovirus B19 “Erythema infectiosum”
Peds: A macular rash over body that appears after several days of high fever; can present with febrile seizures
HHV-6 “Roseola”
UTI Bugs \+ LE \+ Nitrite \+ Urease - Urease
+ LE = bacterial
+ Nitrite = GN
+ Urease = Proteus, Klebsiella
- Urease = E. coli, Enterococcus
UTI: blue-green pigment and fruity odor; usually nosocomial and drug resistant
Pseudomonas aeruginosa
UTI: motility causes “swarming” on agar; produces urease; associated with struvite stones
Proteus mirabilis
UTI: nosocomial and drug resistant (3 examples)
Pseudomonas, enterobacter, serratia
UTI: some strains produce red pigment; often nosocomial and drug resistant
Serratia
UTI: top 3 causes
- E. coli: green metallic sheen
- Staph sapro (Coag-negative): sexually active women
- Klebsiella: large mucoid capsule and viscous colonies
Osteomyelitis: Assume if no other information is available
S. aureus
Osteomyelitis: sexually active
N. gonorrhoeae [Septic arthritis more common]
Osteomyelitis: diabetics & IVDU
Pseudomonas and Serratia
Osteomyelitis: Sickle Cell Disease
Salmonella
Osteomyelitis: prosthetic replacement
S. aureus & S. epidermidis
Osteomyelitis: vertebral disease
M. tb (Pott’s disease)
Osteomyelitis: cat/dog bite/scratch
Pasturella multocida
Osteomyelitis: classic lab finding
Elevated ESR/CRP
UTI: predisposing risk factors
Male risk factors
WBC casts in pyelo or cystitis
Female; obstruction; renal surgery; catheterization; GU malformation; diabetes; pregnancy
Male: congenital defect, VUR, BPH
WBC casts: pyelo
3 bugs that can mimic appendicitis
Yersinia; non-typhoidal Salmonella; Campylobacter jejuni
PNA: nosocomial (2)
Staph
Enteric GNR’s
PNA: IC hosts
Staph Enteric GNR Fungi Viral PCP (HIV)
PNA: aspiration
Anaerobes
PNA: ETOH/IVDU
Staph, S. pna, Klebsiella
PNA: CF
Staph, S. pna, Pseudomonas
PNA: Post-viral
Staph, S. pna, H. influenza
PNA: atypical
Mycoplasma, Legionella, Chlamydia
PNA: elderly
S. pna Influenza Anaerobes H. influenza GNR
PNA: adults 40-65 yo
S. pna H. influenza Anaerobes Viruses Mycoplasma
PNA: adults 18-40 yo
S. pna
C. pna
Mycoplasma
PNA: children < 18 yo
RSV, Mycoplasma, Chlamydia trachomatas (<3yo), C. pna (school-age), S. pna [Runts may cough chunky sputum]
PNA: neonates
GBS, E. coli
Normal dominant flora: skin
S. epi
Normal dominant flora: nose
S. epi; S. aureus colonization
Normal dominant flora: oropharynx
S. viridans
Normal dominant flora: colon
Bacteroides > E. coli
Normal dominant flora: vagina
Lactobacillus, E. coli, GBS
Culture medium: H. influenza
Chocolate agar with factors V (NAD+) & X (hematin)
Culture medium: NM + NG
Thayer-Martin: V
Virulence factor of E. coli that causes neonatal meningitis.
K-capsular polysaccharide
Inactivated toxin vaccines
C. diptheria
C. tetani
Live attenuated bacteria vaccines
M. tb, Francisella, Salmonella
Heat-killed bacterial vaccine
B. pertussis, V. cholera, Yersinia
Recombinant bacterial outer membrane protein vaccine
B. burgdorgeri
Aseptic meningitis in children generally caused by…
Enteroviruses: echo, polio, coxsackie
CMV cellular receptor
Cellular integrins
EBV cellular receptor
CR2 (CD21)
Rabies cellular receptor
Nicotinic ACh receptor
Rhinovirus cellular receptor
ICAM1 (CD54)
Pharynx –> lymphatics –> meninges. Bug?
H. flu
Pharynx –> mucosal epithelium –> B/S –> choriod plexus
N. m
Congenital toxo classic triad
Hydrocephalus, intracranial calcifications, chorioretinitis
Who has LOS: N. m or N. g?
N. m
Anti-phagocytic capsule is a primary virulence factor for:
S. pna, H. flu, N species
Hypervariable pili are characteristic of what bugs?
N. m/N. g
Protein A of this bug binds to the Fc portion of IgG preventing opsonization, phagocytosis, complement fixation
S. aureus
Varicella, mumps and adenovirus are spread by…
Respiratory secretions
T/F Cryptococcus polysaccharide capsule antigen is useful for diagnosis.
True
What fungus is present in soil and pigeon droppings?
C. neoformans
How is cryptococcus neoformans transmitted?
Respiratory route
T/F Oropharynx & nasopharynx are colonized by N. m. If so, what attaches the meningococci to the nasopharnyx?
True; pilus
T/F Staph epidermidis is a common cause of foreign body infections due to its ability to produce adherent biofilms.
True
The clinical presentation of restlessness, agitation, dysphagia and coma 30-50 days following exposure to cave bats is strongly associated with…
Rabies encephalitis
Mycoplasma vs. Mycobacterial (sterols vs. mycolic acid; cell wall?)
Mycoplasma: sterols; no cell wall
Mycobacterial: mycolic acid; high lipid content in cell wall
These bugs do not gram stain.
These rascals may microscopically lack color.
Treponema (thin), Rickettsia (IC), Mycobacteria (high lipid, AF), Mycoplasma (no cell wall), Legionella (IC), Chlamydia (IC; no muramic acid)
Most sensitive test for T. pallidum
Dark-field microscopy and fluorescent Ab staining
Giemsa stain
Certain bugs really try patience
Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium
PAS stain
Stains glycogen; mucopolysaccharides; used to diagnose Whipple’s disease (T. whipplei)
Ziehl-Neelsen stain (carbol fuchsin)
AF: Nocardia, Mycobacterium
India ink stain
Cryptococus neoformans (mucicarmine can be used to stain capsule)
Silver stain
Fungi (PCP), Legionella, H. pylori
Special culture: H. influenza
Chocolate agar with factors V (NAD+) and X (hematin)
Special culture: N. gonorrhea, N. meningitidis
Thayer-Martin media
VPN: Vanco (gram+), Polymyxin (gram-), Nystatin (fungi)
Special culture: B. pertussis
Bordet-Gengou (potato agar)
Special culture: C. diphtheriae
Tellurite, Loffler’s media
Special culture: M. tb
Lowenstein-Jensen agar
Special culture: M. pna
Eaton’s agar
Special culture: lactose-fermenting enterics
MacConkey’s agar (pink colonies)
Aside from MacConkey’s agar, E. coli can be grown on…
Eosin-methylene blue (EMB) as colonies with green metallic shenn
Special culture: Legionella
Charcoal yeast extract agar buffered with cysteine and Fe
Special culture: Fungi
Sabouraud’s agar
OIC bugs
Rickettsia, Chlamydia
* Cannot make own ATP
Facultative IC bugs
Some nasty bugs may live facultativeLY
Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia
Zoonosis: Bartonella
Cat scratch disease
Zoonosis: Borrelia burgdorferi
Lyme disease
Ixodes tick; lives on deer/mice
Zoonosis: Borrelia recurrentis
Recurrent fever
Louse
Zoonosis: Brucella
Brucellosis/undulant fever
Unpasturized dairy
Zoonosis: Campylobacter
Bloody diarrhea
Puppies, livestock (fecal-oral), undercooked
Zoonosis: Chlamydophilia psittaci
Psittacosis
Parrots/birds
Zoonosis: Coxiella burnetti
Q fever
Aerosols of cattle/sheep amniotic fluid
Zoonosis: Ehrlichia chaffeensis
Ehrlichoisis
Lone star tick
Zoonosis: Francisselala tularensis
Ticks, rabbits, derr fly
Zoonosis: Leptospira
Animal urine
Zoonosis: M. leprae
Armadillos and humans with lep. leprosy
Zoonosis: Pasteurella multocida
Cellulitis/osteomyelitis
Animal bite
Zoonosis: Rickettsia prowazekii
Epidemic typhus
Louse
Zoonosis: Rickettsia rickettsii
RMSF
Dermacentor tick bite
Zoonosis: Rickettsia typhi
Endemic typhus
Fleas
Zoonosis: Yersinia pestis
Plague Fleas (rats and prarie dogs = reservoirs)
Food poisoning: contaminated seafood
V. parahemolyticus, V. vulnificus
Food poisoning: reheated rice
Bacillus cereus
Food poisoning: Meats, mayonnaise, custard (preformed toxin)
S. aureus
Food poisoning: reheated meat dishes
C. perfringens
Food poisoning: improperly canned foods (bulging)
C. botulinum
Food poisoning: undercooked meat
E. coli 0157:H7
Food poisoning: poultry, meat, eggs
Salmonella
Bugs that can mimic appendicitis
Yersinia (mesenteric adenitis), Salmonella, Campylobacter
Most common cause of mesenteric adenitis
Yersinia enterocolitica
Antibiotics to avoid in pregnancy (And one antiviral, one antifungal)
* Explain the AE
SAFE Children Take Really Good Care Sulfonamides: kernicterus AG: Ototoxicity FQ: Cartilage damage Clarithromycin: Embryotoxic Tetracyclines: Teeth, bone growth Ribavirin: Teratogenic (antiviral) Griseofulvin: Teratogenic (antifungal) Chloramphenicol: Gray baby
Obligate aerobes
Nagging pests must breath
Nocardia, Pseudomonas, M. tb, Bacillus
Obligate anaerobes
Actinomyces, Bacteroides, Clostridium
Killed/inactivated vaccines include…
Salk (IM), rabies, IM influenza, HAV
Killed/inactivated vaccines induce humoral/cell-mediated immunity or both.
Humoral only (Salk (IM), rabies, IM influenza, HAV)
Recombinant viral vaccines include…
HBV, HPV
Live attenuated viral vaccines include…
Smallpox, yellow fever, VZV, Sabin (oral), MMR, intranasal influenza
Beta-inferferon can treat…
MS
Gamma-interferon can treat…
CGD
Kaposi’s sarcoma can be treated by…
Alpha-interferon
The only DNA virus not replicated in the nucleus.
Pox virus
The 2 RNA viruses not replicated in the cytoplasm
Retrovirus & Orthomyxovirus
The only DNA virus to acquire its envelope from the nucleus vs. the plasma membrane
Herpes virus
The only diploid RNA virus
Retrovirus
CD4 Cut off: AIDS oral thrush
< 400
CD4 Cut off: AIDS Cryptosporidium
< 200
CD4 Cut off: AIDS JC/PML
< 200
CD4 Cut off: AIDS PCP
< 200
CD4 Cut off: AIDS esophageal thrush
< 100
CD4 Cut off: AIDS histoplasmosis
< 100
CD4 Cut off: AIDS toxoplasmosis
< 100
CD4 Cut off: AIDS CMV retinitis
< 50
CD4 Cut off: AIDS cryptococcal meningitis
< 50
CD4 Cut off: AIDS MAC
< 50
The three HIV genes
Env: gp120, 41
Pol: p24
Gag: RT, P, Integrase
Early HIV uses this co-receptor on T cells; late uses
What about on macrophages?
CCR5; CXCR4
Macrophages: CCR5
UTI large mucoid capsule with viscous colonies
Klebsiella pneumonia
UTI red pigment
Serratia
UTI struvite
Proteus
UTI blue-gree pigment
Pseudomonas
UTI: What does leukocyte esterase mean?
Bacteria
UTI: What does nitrite positive mean?
Gram negative
UTI: What does urease positive mean?
Proteus, Klebsiella
UTI: What does urease negative mean?
E. coli, Enterococcus