Gram Positive Flashcards
What are your gram positive, aerobic bacilli?
- Listeria
- Bacillus
- Corynebacterium
What are your gram positive, anaerobic bacilli
Clostridium
Propionibacterium
What are your gram positive, aerobic, branching filaments
Nocardia
weakly acid fast
What are your gram positive, anaerobic, branching filaments
Actinomyces
not acid fast
Catalase positive facultative cocci
Staphylococcus
Catalase negative facultative cocci
Streptococcus
Catalase positive, coagulase positive cocci in clusters
S. aureus
Catalase positive, coagulase negative, novobiocin sensitive cocci in clusters
S. epidermidis
Catalase positive, coagulase negative, not novobiocin sensitive cocci in clusters
S. saprophyticus
[Hemolysis in streptococci]
green, partial
alpha hemolysis
[Hemolysis in streptococci]
comple, clear
beta hemolysis
[Hemolysis in streptococci]
no hemolysis, grows in bile
gamma hemolysis
to differentiate viridans and S. pneumoniae
Optochin Sensitivity
Bile solubility
Optochin sensitive,
alpha hemolytic
catalase negative cocci
S. pneumoniae
Optochin insensitive
Alpha hemolytic
Catalase negative
cocci
Viridans streptococci
How will you differentiate S. agalactiae and S. oyogenes?
Bacitracin
Bacitracin sensitive
beta hemolytic
coagulase negative
cocci
Group A
S. pyogenes
Bacitracin = beta
Bacitracin insensitive
Beta hemolytic
Catalase negative
cocci
Group B S agalactiae
Beta=Bacitracin= group B is negative bacit
How will you differentiate S. bovis from E. faecium and E. faecalis?
Growth in 6.5% NaCl
Grows in 6.5% NaCl
Gamma hemolysis
Catalase negative
cocci
Group D (Enterococcus)
E. faecium
E. faecalis
Does not grow in 6.5% NaCl
Gamma hemolysis
Catalase negative
cocci
S. bovis
The gold color of staphylococcus is due to the pigment:
staphyloxanthin
What are the immunomodulators of S. aureus
- Protein A
- Coagulase
- Cytotoxin
- PV Leukocidin
- Catalase
- Penicillinase
What are the compounds found in S. aureus that plays a role in tissue penetrans?
- Hyaluronidase
- Fibrinolysin
- Lipase
Which is an immunomodulator found in S. aureus
Hyaluronidase or Coagulase
Coagulase
What are the toxins produce by Staphylococcus
- Exfoliatin
- Enterotoxin
- TSST-1
- Alpha toxin
Toxin found in S. aureus that can cause marked necrosis of the skin and hemolysis
Alpha toxin
Toxin in S. aureus that can cause epidermal separation
Exfoliatin
What is the most common cause of acute endocarditis?
S. aureus
preferentially infects Tricuspid valve
___ abscess os a sequestered focus of osteomyelitis arising in the metaphyseal area of a long bone infected by S. aureus
Brodie abscess
S. aureus presents as acute onset gastroenteritis due to presence of ____
preformed heat-stable enterotoxin
___ disease
caused by exfoliatin found in S. aureus that cleaves desmoglein
Ritter disease (SSSS)
separation of epidermis at stratum granulosus
Lyell disease is distringuished from SSS since the separation occurs at the ____
Dermo-epidermal junction
Lyell Disease = TEN
[Diagnose]
fever, hypotension, strawberry tongue, desquamating rash, multiorgan involvement
Blood CS negative
Toxic Shock Syndrome
What is the DOC for MSSA?
- Nafcillin
- Oxacillin
- Dicloxacillin
What is the DOC for VRSA?
Linezolid
Component of S. aureus that prevents complement actiation
Protein A
Bacteria that are novobiocin senstiive
Novo resistant Saprophyticus
Novo sensitive epidermidis
____ that adheres well to foreign bodies and form biofilms (like in prosthetic joints amd vpl shunts)
S. epidermidis
Tx: Remove prosthetic device, treat with vancomycin
What is the second most common cause of UTI in sexually active women?
nitrite negative
S. saprophyticus
DOC: TMP-SMX
___ test
measures hydrolysis of 1-pyrrolidonyl beta naphthylamide and release of beta napththylamine
PYR test
Postive in S. pyogenes
Bacitracin sensitive organisms
Bacitracin
B Resistant
A Sensitive
Remember: BRAS
What is the spreading factor of S. pyogenes?
Hyaluronidase
What activates plasminogen in Streptococcus?
Streptokinase
What virulence enzyme present in
S. pyogenes that degrades DNA in exudates or necrotic tissue
DNAse or Streptodornase
What virulence enzyme present in
S. pyogenes that inactivates complement C5A
C5A peptidase
What toxin in S. pyogenes that cause scarlet fever?
Erythrogenic toxin
What toxin found in S. pyogenes that is highly antigenic that causes antibody formation?
Streptolysin O
Oxygen-labile
Toxin of S. pyogenes that is oxygen-stable and is similar to TSST?
Pyrogenic Exotoxin
Toxin of S. pyogenes that is oxygen-stable that is a protease that rapidly destroys tissue
Exotoxin B
What is the major virulence factor for group A strep which inhibits the activation of complement and protects the organism from phagocytosis
M protein
___ is the titer used to document antecedent pharyngitis
ASO
___ is the titer used to document antecedent strep skin infection
Anti-DNAse B
____ presence of this decrease the efficacy of streptokinase in managing MI
Anti-streptokinase
In impetigo contangiosa, neturophils accumulate in ___
beneath stratum corneum
Superficial infection of S. pyogenes that extends to dermal lymphatics
Erysipelas
Deeper skin infection caused by S. pyogenes extending to SQ facilitated by hyaluronidase
Cellulitis
Necrotizing fasciitis due to S. pyogenes is facilitated by
Exotoxin B
NecFas = deep SQ tissue, but not hyaluronidase
Quincy abscess due to S. pyogenes is seen in which part of the body
Retropharyngeal
[Diagnosis]
fever, strawberry -like, centrifugal sandpaper-like centrifugal rash, pastia lines, desquamation
Scarlet fever
___ is the method of susceptibility to scarlet fever by injection into the skin of 0.1 cm3 of scarlet fever toxin
Dick Test
Dick = Scarlet
___ is the method od diphteria toxin susceptibility testing
Schick test
Schick = Diptherria
Streptococcal Toxic Shock Syndrome is milder than S. aureus TSS. This is due to what toxin ___
Blood culture are often positive
Pyrogenic Exotoxin A
Antibodies developing due to S.pyogenes infection is due to what toxin ____
M proteins
What is the most common cause acute rheumatic fever?
S. pyogenes
DOC: pen G
[Diagnose]
Hematuria, hypertension, periorbital edema after tonsillitis
PSGN
Rheumatic fever is a classified as what type of hypersensitivityreaction?
Type II = IgG and IgM mediated
PSGN is what type of hypersensitivity reaction/
Type III = Immune complex
What are the predisposing factors for S. agalactiae infection?
- Intrapartum fever >38 degC
- PROM >18h
- Vaginal colonization
- Complement deficiency
All pregnant women should be screened for GBS colonization at ___ weeks
35 to 37 weeks AOG
Streptococcus that can cause UTI due to indwelling urinary catheter and urinary tract instrumentation
GDStrep
___ cause endocardities in patients who underwent GIT surgery
E. faecalis
Marantic endocarditis in patients with abdominal malignancy is due to ____
S. bovis
DOC: Penicilin + gentamicin
Cephalosporins are not active agains what microbes
- Enterococci
- Listeria monocytogenes
- MRSA
Lancet shaped, G+
S. pneumonieae
Optochin sensitive streptococcus
Optochin
Viridans Resistant
Pneumonia Sensitive
OVeR PaSS
What are your encapsulated bacteria?
- S. pneumoniae
- K. pneumoniae
- H. influenzae
- P. aeruginosa
- N. meningitidis
- S. typhi
- B group strep
What substance plays a role in colonization of S. pneumoniae?
IgA protease
What substance present in S. pneumoniae reacts with CRP
c-substance
[Diagnose]
Cough
blood-tinged, pink or rusty sputum
Pneumonia
S. pneumonia
most common cause of pneumonia
DOC: pen G
S. pneumoniae vaccin is conjugated with what carrier protein
Diphtheria toxoid
Viridans mutans enter the bloodstream during ____
dental procedures
Viridans step are known to cause damage in heart valves due to the presence of ___-
glycocalyx
Viridans mutans that can cause subacute bacterial endocarditis (most common cause of subacute and native valve endocarditis)
S. sanguis
Viridans mutans that can cause brain abscess
S. intermedius
box car shape
B. anthracis
Aerobic, motile, reheated fried rice
B. cereus
tennis racket like, anaeribic
C. tetani
Anaerobic, bulging cans
C. botulinum
Anaerobic, gas forming, lecithinase
C. perfringes
Anaerobic, pseudomembranous colitis
Clostridiodes difficile
chinese characters, curved, aerobic, non motile
C. diphtheriae
tumbling motility
aerobic, curved
L. monocytogenes
___ dry, ground glass surface and irregular edges with projection along lines of inoculation of B anthracis
Medusa head morphology
Woolsorters disease
B. anthracis
[B. anthracis virulence factors]
calmodulin-dependent adenylate cyclase
edema factor
[B. anthracis virulence factors]
inhibit signal transduction in cell division
lethal factor
[B. anthracis virulence factors]
mediates entry of the EF and LF
protective antigen
In inhalational anthax, what lymph nodes are massively enlarged
mediastinal
What is the DOC for cutaneous anthrax
ciprofloxacin
Most common cause of death is pulmonary hemorrhage in these organisms
- Anthrax
- Leptospirosis (Weil’s)
- Congenital syphilis
Toxin found in B. cereus that cause cholera-like enterotoxin
Heat-labile enterotoxin
Rapid onset vomiting after ingestion of B. cereus is due to what type of toxin
heat-stable toxin
Diarrhea after intake of fried rice is due to what toxin found in B. cereus?
heat-labile
Tetanospasmin cleaves proteins involved in the release of glycine from what cels in the spinal cord
Renshaw cells
Tetanospasmin cleaves GABA release by cleaving ____
synaptobrevin 2
What organism is seen in alkaline vegetables like green beans, pepper, mushroom that produces toxin?
C. botulinum
The flaccid paralysis in botulinum toxin ingestion has a __ _ pattern
Descending
Botox is a commercial preparation of what botulinum toxin
Toxin A
What are the bulbar signs of food-borne botulism
- Diplopia
- Dysphonia
- Dysarthria
- Dysphagia
What are the initial symptoms of C. botulinum?
muscle aches, trismus, myalgia
At the presynaptic terminal, tetanus toxin inhibits ___
release of GABA, resulting to rigidity
At the NMJ, tetanospasmin ____ release
blocks NT release, this weakness and paralysis
[Daignose]
symmetric descending flaccid paralysis, absence of fever, intact sensorium
Botulism
Infant botulism can happen after ingestion of household dust or honey because there is __-
absence of competitive bowel microbes
___ double hemolysis on blood agar
C. perfringes
Gas gangrene due to C. perfringes is due to ___
- alpha toxin (lecithenase)
Exotoxin in stool of this organism is detected by cytopathic effect in culture
Clostridioides difficile
What drugs are associated with C. difficile overgrowth?
- Clindamycin
- 2nd and 3rd generation cephalosporin
- Ampicillin
In C. difficile, these toxins inhibits GTPases leading to apoptosis of enterocytes
- Exotoxin A (enterotoxin)
- Exotoxin B (cytotoxin)
This results to pseudomembrane
What bacteria is implicated in flare ups of UC
C. difficile
What is the DOC for C. difficile?
Vancomycin
___ is associated with toxic shock syndrome associated with septic abortion
S. sordellii
Box-car shaped rods but lipase negative, lecithinase positive
C. perfringes
Horse-barn odor, ground glass appearing colonies
C. difficile
In potassium tellurite, corynebacterium grow as ____ colones
dark black
Loeffler’s medium is used for C. diptheriae. the stain used is
methylene blue
What test is used to detect toxigenicity of C. diphtheriae
Modified Elek Test
C. diptheriae has an exotoxin that inhibits protein synthesis by adding ADP ribose to ___
Elongation factor 2
Which exotoxin of C. diphteriae has ADP ribosylating activity?
Subunit A
Which exotoxin of C. diphteriae binds the toxin to cell surface?
Subunit B
What encosed C. diphtheriae exotoxin
beta-prophage
What are the characters of diphteria?
ADP-ribosylation Beta-prophage Corynebacterium Diphteriae Elongation Factor 2 Granules are metachromatic
V or L shape; paradoxical growth in cold temperature
L. monocytogenes
___ toxin of L. monocytogenes that interacts with E-cadherin
Internalin
___ toxin of L. monocytogenes that helps it escape from phagosome
listeriolysin
___ toxin of L. monocytogenes that helps the bacteria propel through the membrane of one human cell into anotehr
Actin rockets (actin polymers)
What are the characteristics of early onset neonatal listeriosis or granulomatosis infantiseptica?
- Late miscarriage or birth complicated by sepsis
- multiorgan abscess
- disseminated granulomas
What is the DOC for L. monocytogenes?
Ampicillin