Bacteriology Flashcards
The gold color of S. Aureus is due to the pigment
Staphylotoxin
Habitat of s. Aureus
Anterior nares
Beta hemolytic bacteria
S. Aureus
S. Pyogenes
S. Agalactiae
Listeria
Immunimodulator in S. aureus responsible for preventing complement activation
Protein A
Immunimodulator of S. aureus specific for WBC
Panton valentine leukocidin
Other name of hyaluronidase
Spreading factor
Toxin of staph aureus responsible for epidermal separation
Extoliatin
Toxin of s. Aureus that causes necrosis of the skin and hemolysis
Alpha toxin
Differentiate impetigo in staph and strep
Staph aureus - impetigo bullosa
strep - impetigo contagiosa
Most common cause of acute endocarditis
Staph aureus
Sequestered focus of osteomyelitis arising in the metaphyseal area of long bones
Brodie abscess
MC Cause of septic arthritis
Staph aureus
Most common cause of septic arthritis in sexually active people
N. Gonnorhoea
Mechanism of exfoliatin in SSSS
Exfoliatin cleaves desmoglein in desmosomes
In ritter disease, separation of the epidermis happens in what layer? In TEN?
Stratum granulosum
Dermo-epidemoid junction
Toxic shock syndrome is due to what toxin
TSST-1
Unique to toxic shock syndrome of staph compared to strep
No demonstrable focus and blood cs is negative
Usual risk factor/scenario in staph aureus TSS
Tampon-using
Nasal packing
Heirarchy of treatment of S.aureus
MSSA - penicillinase resistant penicillins (nafcillin, oxacillin,dicloxacillin)
MRSA- vancomycin
VRSA - linezolid
Morphology of staph epid in blood agar
Whitish
Non-hemolytic
Previously called staphylococcus albus
Mnemonic for novobiocin sensitivity
NO StRES
Novobiocin
Saprophyticus resistant
Epidermidis sensitive
Staph epid contains ____ that makes it adhere well to foreign bodies
Glycocalyx
Most common cause of prosthetic valve endocarditis/septic arth in prosthetic joints/VP shunts
S. epidermidis
Treatment of staph epid
Vancomycin (50% are resistant to Methicillin)
Treatment for catalase pos, coagulase neg bacteria
Vancomycin
2nd most common cause of UTI in sexually active women
S. Saprophyticus
Treatment for Staph saprophyticus
TMP-SMX
QUINOLONES
Catalase negative
Alpha hemolytic
Bile optochin sensitive
S. Pneumoniae
Catalase negative
Alpha hemolytic
Bile optochin resistant
Viridans streptococci
Catalase negative
Beta hemolytic
Bacitracin sensitive
S. Pyogenes
Catalase negative
Beta hemoytic
Bacitracin resistant
S. agalactiae
Catalase negative
Gamma hemolytic
Group D strep
Group A and Group B in strep are named ____ grouping
Lancefield grouping
A positive PYR test for a streptococci rule in
S. pyogenes and group D streptococci
Mnemonic for bacitracin sensitivity
B-BRAS
Bacitracin
B strep - resistant
A strep sensitive
Other name of DNase in strep pyogenes?
What is its function?
Streptodornase
Degases DNA in exudates or necrotic tissue
Toxin thag produced scarlet fever
Erythrogenic toxin
Oxygen labile and oxygen stable toxins of strep
Streptolysin O - oxygen labile
Streptolyson S - oxygen stable
Superantigen found in strep similar to TSST-1
Pyogenic exotoxin A
Protease that rapidly destroys tissue causing necrotizing fasciitis in strep pyogenes
Exotoxin B
Documents antecedent skin infection for s. Pyogenase
Anti-DNase B
In impetigo contagiosa, neutrophils accumulate in what layer of the epidermis?
Beneath the stratum corneum
Cellulitis is facilitated by what factor in strep pyogenes?
Spreading factor or hyaluronidase
Necrotizing fasciitis is facilitated by what toxin in strep pyogenes
Exotoxin B
Most common bacterial cause of sore throat
S pyogenes
Characteristic of rash in scarlet fever
Sandpaper rash
Found on armpits and inguinal area in scarlet fever
Pastia’s lines
Susceptibility test for scarlet fever
Dick test
In streptococcal toxic shock syndrome, there is no demonstrable focus and blood cs is usually negative. t or F
F
PSGN is most common post pharyngitis or post impetigo?
Postimpetigo
DoC in GABHS
Penicillin G
GBS can hydrolyze
Hippurate
Habitat of GBS
Vagina
Test to identify GBS
CAMP test
GBS can be cultured using what broth
LIM broth
Most common cause of neonatal meningitis
GBS
Drug of choice in GBS
Penicillin G
All pregnant women should be screened for GBS at what AOG
35-37 weeks
Chemoprophylaxis with what 4hrs prior to delivery should be done for GBS
IV penicillin
Ampicillin
4 hrs prior to delivery
group D strep hydrolyzes
Esculin
BEA - bile esculin agar
How do you differentiae E. Faecalis from s. Bovis?
E faecalis can grow in 6.5% NaCl
S. bovis does not
Endocarditis for patients who underwent GI surgery is usually due to
E. faecalis
_____ endocarditis is seen in patients with abdominal malignancy due to S. bovis
Marantic endocarditis
Lancet shaped cocci
Strep pneumoniae
Strep pneumonia is positive in what reaction
Quellung reaction
Mnemonic for optochin sensitivity
OVERPAS
Optochin
Viridans resistant
Pneumoniae sensitive
Mnemonic for Quellung reaction
Quellung- capsular swellung
Mnemonic for encapsulated bacteria
Some killers have pretty nice and shiny bodies
Strep pneumoniae Klebsiella Haemophilus influenza Pseudomonas aeruginosa Neiserria meningitidis Salmonella typhi B group streptococci
In strep pneumoniae, ____ reacts with CRP, ___ is for colonization, and ____ retards phagocytosis
C-substance
IgA protease
Capsule
Carrier protein of conjugated vaccine for pneumonia
Diphtheria toxoid
Viridans streptococci is a group if bacteria composed of
S. Mutans
S. Sanguis
S intermedius
Viridans strep implicated in dental caries
S mutans
Mnemonic for bile optochin resistance
Viridans strep live in the mouth hence they are not afraid OP THE CHIN (optochin resistant)
Viridans strep impliated in subacute bacterial endocarditis
S. Sanguis
Viridans strep implicated in brain abscess
S intermedius
Spore forming genus in gram positive rods
Clostridium
Bacillus
Aerobic non motile box car shaped gram positive rod
Bacillus anthracis
Spore forming gram positive rod
Anaerobic
Tennis racket like
Clostridium tetani
Type of paralysis in tetanus vs botulinum
Spastic - tetanus
Flaccid - botulinum
Medusa head morphology
Bacillus anthracis
Gram positive rod
Double hemolysis
Clostridum perfringens
Agar for clostridium perfringens
Egg yolk agar
Antibiotic associated diarrhea
C. Difficile
Aerobic, non motile
Chinese characters
Gram positive rod
Corynebacterium diphtheriae
Tumbling motility
Listeria monocytogenes
Anthrax habitat
Soil
Antiphagocytic capsule in anthrax
Poly d glutamate
2 factors in anthrax
Lethal factor and edema factor
Anthrax Factor that inhibits signal transduction in cell division
Lethal factor
Mediates entry of the 2 factors in anthrax
Protective antigen
In cutaneous anthrax, there is formation of
Malignang pustule
With eschar and central necrosis
Transmission of anthrax
Infected animals or inhalation of spores from animal hair or wool
Other name for bacillus anthracis
Woolsorter’s disease
When anthrax is inhaled, do we see the effects immediately?
No. There is a prolonged latent period of 2 months.
Death from inhalational anthrax is due to
Hermorrhagic mediastinitis
Most common cause of death is hemorrhagic mediastinitis in these diseases
Mediastinal anthrax
Weil’s syndrome
Congenital syphilis
Mortality rate in cutaneous anthrax compared to GI and inhalational
Cutaneous 20%
Inhalational and GI - 100%
DOC for cutaneous anthrax
Ciprofloxacin
DOC for inhalational or GI anthrax
Cipro or doxy plus 2 additional antibiotics
Enterotoxins in B.cereus
Heat labile enterotoxin and heat stable enterotoxin
Heat stable vs heat labile toxin of b. Cereus
Heat stable - staphylococcal like
Heat labile - cholera like
Spectrum of disease in B cereus
Emetic form
Diarrheal form
Ophthalmitis
Clostridium tetani spore is at one end rendering it with that _____ look
Tennis racket
Habitat of clostridium tetani
Soil
Tetanus toxin
Tetanospasmin
Action of tetanospasmin
Protease that cleaves proteins involved in the release of glycine in Renshaw cells
DOC for tetanus (differentiate between DOC in all other textbooks and harrisons)
PEN G
Harrisons- metrondiazole
If wound is clean,minor and the latieng has less than 3 doses of tetanus toxoid what do we do?
Administer TeANA (toxoid)
If a person has a contaminated wound with more than 3 doses of tetanus toxoid before more than 5 years ago, do we still give the toxoid?
Yes
Botulinum toxin is heat labile or stable?
Heat labile
How many typesnof toxins are seen in botulinum and what types are most common in humans?
8 types
Type A B E
Botox is a commercial preparation of exotoxin ___
A
Bulbar signs of food borne botulism
Diplopia
Dysphonia
Dysarthria
Dysphagia
Triad of botulism
Flaccid paralysis with prominent bulbar involvement
Absence of fever
Intact sensorium
Infant botulism is due to
Absence of competitive bowel microbes
Botokinum antitoxin
Trivalent (ABE)
Clostridium perfringens shows what type of hemolysis in blood agar
Double hemolysis
Clostridium perfringens grows on
Egg yolk agar
Gas gangrene in clostridium perfringens is caused by which of the ff toxins
Alpha toxin (lecithinase)
Exotoxin is found where in clostridium difficile infection?
Stool
Exotoxin in stool is detected by
Cytopathic effect on cultured cells or elisa
Transmission of C difficile
Fecal oral route
Hands of hospital personnel
Culprit antibiotics in c difficile infection
Clinda, 2 and 3rd gen cephalosporin
Ampicillin
Visual result of exotoxin A and B in c difficile
Pseudomembranes
Infection of c difficile can precipitate flare ups of
Ulcerative colitis
What causes psudomembranous pharyngitis
C diphtheriae
What causes pseudomembranous esophagitis?
Candidiasis
Treatment for c dofficile infection
Withdraw causative antobiotic
Treat with oral metronidazole or vancomycin
Club or comma shaped gram pos rods arranged in V or L
C diphtheriae
Chinese characters
C diptheriae
Granules found in diphtheria
Babes ernst granules/ volutin granules
C diphtheriae are black colonies in what agar?
Tellurite agar
Exotoxin of C. diphtheriae inhibits protein synthesis by adding ADP ribose to
Elongation factor 2 (EF2)
Subunit ___ of the exotoxin of diphtheria binds the toxin to cell surface while subunit ___ has ado robosylating activity
B
A
Exotoxin in diphtheria is encoded by a
Beta prophage
ABCDEFG of diphtheria
ADP ribosylatiob Beta prophage Corynebacterium Diphtheriae Elongation factor 2 Granules (metachromatic)
ABCDE of beta prophage encoded toxins
Shiga like toxin (EHEC) Botulinum toxin Cholera toxin Diphtheria toxin Erythrogenic toxin
Treatment of diphtheria
Antitoxin and pen G
Diphtheria toxid is usuallly combined with
Tetanus toxoid and pertussis
Motility of listeria
Tumbling
Pattern of hemolysis of listeria
Narrow beta hemolysis
Weird characteristic of listeria growth
There is paradoxical growth in cold temp (cold enhancement)
Transmission of listeria
(placenta or delivery)
Listeria can be ingested in
Unpasteurized milk products
Pathogenesis of listeria (3)
Internalin
Listeriolysin
Actin rockets
Escape from phagosomes is done by listeria through
Listeriolysin
Moa of internalin in listeria infxn
Interacts with E cadherin in the surface of cells
Early onset neonatal listeriosis is also known as
Granulomatosis infantiseptica
Late onset neonatal listeriosis usually manifests as
Meningitis
Treatment for listeria
Ampicillin with or without gentamicin
Encapsulated gram neg diplococci thag ferments maltose and glucose
N. meningitidis
Gram neg diplococci
Insignificant capsule
Ferments glucose
N. gonorrhoea
N meningitidis is known as a disease of ___ hence its high carriage rate in _____
Proximity
Close quarters
Only natural hosts of N. Meningitidis
Humans
Late acting complement components
C5-C9
Which form of meningitis is more severe? Presence of rash or headache and stiff neck
Rash - shows dissemination in meningococcemia
What do you call the purpuric rash in meningococcemia
Purpura fulminans
Most severe form of meningococcemia
Waterhouse friderichsen syndrome
Treatment for meningococcemia
Pen G
Meningococcal vaccine contains polysaccharide strains of
A C Y W135
Meningococcal vaccine is usually coupled to this carrier protein to enhance immunogenicity
Diphtheria toxoid
What drug do you give to close contacts for chemoprophylaxis of meningococcemia
Rifampicin
HACEK organisms
Haemophilis aprophilus Actinobacillus actinomycetemcomitans Cardiobacterium hominis Eikenella corrodens Kingella kingae
Capsule diff of meningitidis and gonorrhoea
Meningitidis - encapsulated
Gonorrhea - insignificant capsule
N meningitidis is oxidase positive in what agar while N gonorrhoea is oxidase positive in what agar?
Chocolate agar
Thayer martin agar
Thayer martin agar contains ___ to isolate growth of N. gonorrhoea
VCN
Vancomycin
Colistin
Nystatin
In gonorrhoea, there is usually co infection of
Chlamydia trachomatis
Most common cause of urethritis
N gonorrhea
Cervical infection with gonorrhea but with no complication of chlamydia
Uncomplicated gonococcal cervicitis
Treatment for gonorrhea
Ceftriaxone + doxycycline (for chlamydia)
Change doxy to azithromycin in pregnant patients
Cause of culture negative subacute bacterial endocarditis
Eikenella corrodens
Kingella kingae
Check HACEK group
Mnemonic for zoonoses
Bugs from your pets
Brucella abortus
Francisella tularensis
Yersinia pestis
Pasteurella multocida
Bordet gengou agar
Bordetella pertussis
Capsule of H influenzae
Type B Polyribitol phosphate
Agar medium for h. Influenzae
Chocolate agar with factor X (hemin) and factor V (NAD)
Legionella stain
Silver stain
Bacteria associated with airconditioning
Legionella
Agar for legionella
Charcoal yeast agar
H. Influenzae - S aureus relationship
Satellite phenomenon
Needs Factor V NAD of S. aureus
Most common cause of epiglotitis
H. influenzae
Most common cause of LTB
ParainfluenzA 1 and 2
Treatement for LTB
Racemic epinephrine
Mnemonic H influenzae
h influenzae causes
haEMOPhilus
EMOP
Epiglotitis
Meningitis
Otitis media
Pneumonia
Treatment for H influenzae infection
Ceftriaxone
Bacterial LTB
Bordetella pertussis
Culture media for bordetella pertussis
Regan Lowe charcoal medium
Causes whooping in pertussis
Tracheal cytotoxin
Pathogenesis of whooping cough
Filamentous hemagluttinin
Pertussis toxin
Tracheal cytotoxin
False adenylate cyclase
Other name for pertussis
Tuspirina
Tx for whooping cough
Erythromycin
Facultative intracellular bacteria mnemonic
Some Bugs May Live FacultitaveLY
Salmonella Brucella Mycobacterium Listeria Francisella Legionella Yersinia
3 most common causes of atypical pneumonia
Legionella
Mycoplasma
Chlamydia pneumoniae
Sole virulence factor of legionella
Endotoxin
Legionella causes atypical pneumonia. However there is a mild flulike illness that it also causes called ____
Pontiac fever
Comma shaped bacteria
CHV
Campylobacter jejuni
Helicobacter pylori
Vibrio cholerae
Mnemonic for lactose fermenters
Lactose is KEE, grow in MacConKEE agar
CKEE
Citrobacter
Klebsiella
Escherichi
Enterobacter
Campylobacter grows on
Skirrow’s agar
Mrophology of E coli on EMB agar
Green sheen (metallic)
Typing of E. Coli is by
O and H antigens
Enterotoxins of E coli
HST and HLT cause watery diarrhea
Verotoxin (shiga like) toxin causes bloody diarrhea
Mnemonics for enterobacteriaceae
MESSY SPECK
Morganella Escherichia Shigella Salmonella Yersinia
Serratia Proteus Enterobacter Citrobacter Klebsiella
Most common causes of neonatal meningitis
BEL
B group streptococci
E coli
Listeria
E coli strain that cause HUS
EHEC
E coli strain with bloody diarrhea but no HUS
EIEC
E coli strain in HIV
EAEC
Enteroadherent e coli
Salmonella culture
XLD medium
Xylose lysine deoxycholate medium