M5 PART 1-3 Flashcards
gram-positive spore-forming bacilli
Bacillus
Clostridium
gram-positive spore-forming bacilli
aerobes
Bacillus
gram-positive spore-forming bacilli
anaerobes
Clostridium
- resting cells
- dormant
- highly resistant
- are formed when their environment is depleted
- resistant to heat so kahit lutuin buhay pa rin
ENDOSPORES
- a classical disease in the history of microbiology that is caused by Bacillus anthracis
- important disease of animals & occasionaly humans
- has potent toxins and is a major potential agent of bioterrorism & biologic warfare
ANTHRAX
causes food poisoning & occasionally eye or other localized infections
Bacillus cereus
Bacillus species
Large, ____, Gram-positive rods in chains
aerobic
Bacillus species
Possess virulence ____
PLASMIDS
Bacillus species
- most of this genus are ____, prevalent in soil, water, and air, and on vegetation
- they feed on decaying matter
SAPROPHYTIC
Bacillus species
Forms nonhemolytic gray to white colonies
(____)
MEDUSA HAIR, CURLED HAIR
Bacillus species
Spores are located ___
CENTRALLY
Bacillus anthracis
Cell wall is made up of amino acid: ______
poly-γ-D-glutamic acid
Bacillus anthracis
Disease: ____
ANTHRAX
- commonly found in animals (herbivores)
- has capsule
- non motile
- antiphagocytic
Bacillus anthracis
a disease of the herbivores
* ex. cow when eating grass can acquire from soil & can hawa from animal to humans
ANTHRAX
Bacillus anthracis
Pathogensis: based primarily on the production of ____
ANTHRAX TOXIN
Bacillus anthracis | ANTHRAX TOXIN
causes edema (swelling)
EDEMA FACTOR (EF)
Bacillus anthracis | ANTHRAX TOXIN
causes death of the cell by necrosis o hypoxia
LETHAL FACTOR (LF)
Bacillus anthracis | ANTHRAX TOXIN
- a protein that binds to specific cell receptors
- forms a membrance channel so that EF & LF can enter the cell
PROTECTIVE ANTIGEN (PA)
cell death
NECROSIS
cell does not have oxygen
HYPOXIA
Bacillus anthracis
- is usually acquired by the entry of spores through the injured skin
- form accounts for over 95% of anthrax cases
- forms black eschar
- A pruritic papule develops 1-7 days after entry of the spores
CUTANEOUS ANTHRAX
Bacillus anthracis
- rare case of anthrax in humans
- can be accumulated from food contaminated by anthrax
- abdominal pain, vomiting, diarrhea
GASTROINTESTINAL ANTHRAX
- Wool sorter’s disease: from wool of sheep
- severe case of anthrax
- 5% of anthrax cases
- once inhaled, mapunta sa alveoli of lungs, then papasok sa blood and then kakalat infection can be systemic
- mediastinal widening: important diagnostic criterion (by xray)
INHALATION ANTHRAX
Bacillus anthracis
- among persons who inject heroin contaminated with anthrax spores
- resembles cutaneous anthrax
- characterized by extensive, painless subcutaneous edema and the notable absence of the eschar
INJECTION ANTHRAX
Bacillus anthracis
Drug of Choice
Ciprofloxacin
Bacillus anthracis
Vaccine
AVA Biothrax Vaccine
Bacillus anthracis
Prophylaxis (prevention)
3 doses of biothrax vaccine
ciprofloxacin or doxycycline for 60 days
Bacillus cereus is also known as
FRIED RICE BACILLI
BACILLUS SPECIES
- causes food poisoning
- 2 distinct forms: emetic & diarrheal
- 1-5 hours incubation period
- hemolytic (destroys RBC)
- motile
BACILLUS CEREUS
incubation period of Bacillus cereus
1-5 hours
Bacillus cereus
- seen in fried rice, pasta, milk
- nausea, vomiting, abdominal cramps
EMETIC TYPE
Bacillus cereus
- meat dishes & sauces
- profuse diarrhea with abdominal pain & cramps
DIARRHEAL TYPE
B. cereus produce toxins that cause disease that is more of ____ than a food-borne infection
INTOXICATION
Bacillus cereus
EYE INFECTIONS
severe keratitis
endophthalmitis
Bacillus cereus
other clinical findings
ENDOCARDITIS
OSTEOMYELITIS
PNUEMONIA
CNS INFECTIONS
Bacillus cereus
catheter-associated ____
CLINICAL FINDINGS
BACTEREMIA
Bacillus cereus | TREATMENT
Foodborne infection
- self limiting
- stay hydrated – drink ORS
how to make ORS oral rehydration salts
6 tsp sugar, half level tsp salt, 1L water
Bacillus cereus | TREATMENT
Non-foodborne infection:
▪ ____ or ____ with or
without an aminoglycoside
Vancomycin
Clindamycin
Bacillus cereus | TREATMENT
Non-foodborne infection:
▪ ____ - wound infections
Ciprofloxacin
- large, anaerobic, gram +
- saprophytes
- spore is placed centrally, subterminal (gitna ng dulo at central), or terminally (dulo)
- can ferment variety of sugars & digest proteins
CLOSTRIDIUM SPECIES
Clostridium species
Large, ____, Gram-positive ____rods
Anaerobic, motile
Clostridium species
Spore is placed
3
centrally, subterminally, terminally
Clostridium species
can ____ variety of ____ and ____
ferment variety of sugars & digest proteins
- causes botulism
- produce 7 antigenic varieties of toxin
- toxin is potent
- found in soil, occasionally in animal feces
- highly resistant to heat, withstanding 100ºC for several hours
CLOSTRIDIUM BOTULINUM
Clostridium botulinum
Disease:
BOTULISM
Clostridium botulinum
Antigenic varieties affecting humans:
types A,B,E & F
Clostridium botulinum
Botulinum toxin blocks the release of
____ resulting to _____
ACETYLCHOLINE, FLACCID PARALYSIS
clostiridia grow well on what culture media
BLOOD-ENRICHED MEDIA
some clostiridia form colonies that ____ on the agar surface
spread or swarm
many clostiridia produce a zone of ____ on blood agar
β-hemolysis
characteritically produces a double zone of β-hemolysis around colonies
Clostiridium perfringens
Clostridium botulinum
types that have been associated with variety of foods
A & B
Clostridium botulinum
types that have been predominantly associated with fish products
E
Clostridium botulinum
type that produces limberneck in birds
C
Clostridium botulinum
type that causes botulism in mammals
D
Clostridium botulinum
type that is not associated with disease
G
Clostridium botulinum
once acquired -> go blood -> go brain (which part of the brain?)
presynapse, presynaptic membranes
Clostridium botulinum
- inhibits the release of acetylcholine at the synapse
- resulting in lack of muscle contraction & paralysis
- by the L chain of botulinum toxin
PROTEOLYSIS of the target SNARE proteins
Clostridium botulinum
SNAP PROTEINS
synaptobrevin
SNAP 25
syntaxin
most toxic substances known
C. botulinum toxins
Clostridium botulinum
what is needed to release acetylcholine
FUSION (snare proteins)
Clostridium botulinum
- canned good bacilli
- commonly seen in spiced, smoked, vacuum packed (because it has anaerobic environment)
- Botulism characterized by weakness of the eye muscles, drooping eyelids
- usual cause of death is respiratory related
- the effect is from head to toe (ulo muna pababa)
FOOD BOTULISM
Clostridium botulinum
- most frequent vehicle is honey
- the infant develops FLOPPY BABY SYNDROME
- Adults with gastrointestinal anatomical abnormalities or functional disorders may develop this
INFANT BOTULISM
Clostridium botulinum
- result of tissue contamination with spores
- seen primarily in injection drug users
WOUND BOTULISM
Clostridium botulinum
TREATMENT & PREVENTION
- Respiratory support
- Trivalent antitoxin (ABE)
Clostridium botulinum
TREATMENT & PREVENTION:
for infants
botulinum immune globulin (BIG)
- causes tetani
- Non communicable
- all share a common O antigen
- all produce the same type of antigenic type of neurotoxin
- uncontrollable muscle spasms
CLOSTRIDIUM TETANI
Clostridium tetani
Disease
TETANUS
Clostridium tetani
Neurotoxin produced:
TETANOSPASMIN
Clostridium tetani
blocks the release of inhibitory mediators resulting to hyperreflexia, muscle
spasms
TETANUS TOXIN
Clostridium tetani
tetanus toxin blocks the release of ____ resulting to _____
inhibitory mediators
hyperreflexia, muscle spasms
Clostridium tetani
forced grin
Risus sardonicus
Clostridium tetani
lock jaw
Trismus
Clostridium tetani
severe case of tetanus
OPSITHOTONOS
Clostridium tetani
tetanus vaccine
DPT
Clostridium tetani
TREATMENT
muscle relaxants, sedation & assisted ventilation
IV tetanus antitoxin
Clostridium tetani
ANTIBIOTIC
PENICILLIN
Clostridium tetani
PREVENTION
- wound cleaning & debridement
- Tetanus antitoxins & toxoid booster w penicillin (passive-active immunity)
Clostridium perfringens
Diseases
Gas gangrene
Food poisoning
Clostridium perfringens
Toxins porduced
- Alpha toxin
- Theta toxin
- Epsilon
- DNase and hyaluronidase
- Enterotoxin
Clostridium perfringens | TOXINS
hemolytic & necrotizing effect
ALPHA TOXIN (lecithinase)
Clostridium perfringens | TOXINS
the alpha toxin is a
lecithinase
Clostridium perfringens | TOXINS
forms pores in cell membranes
theta toxin
Clostridium perfringens | TOXINS
edema & hemorrhage
Epsilon toxin
Clostridium perfringens | TOXINS
causes the spread of bacteria
DNase & hyaluronidase
Clostridium perfringens | TOXINS
- food poisoning
- meat dishes
Enterotoxin
Clostridium perfringens
- spores reach the traumatized tissue or from the intestinal tract
- necrosis
- in large wounds cause by accidents
- vegetative cells multiply, ferments carbohydrates, and produce gas
GAS GANGRENE
Clostridium perfringens
Gas gangrene is also known as
Clostridial myonecrosis
Clostridium perfringens
- diarrhea & cramps
- source: poultry products
- enterotoxin (targets GI tract)
FOOD POISONING
Clostridium perfringens
TREATMENT
- surgical debridement
- hyperbaric oxygen
- penicillin G antibiotics
- polyvalent toxin
all that can cause food poisoning has
ENTEROTOXIN
Clostridium perfringens
TREATMENT:
food poisoning
symtpomatic treatment
common cause of nosicomial infection (hospital acquired)
CLOSTRIDIUM DIFFICILE
Clostridium difficile
- seen in patients w diarrhea & have been giving antibiotics
- produces potent enterotoxins (A & B)
- once produce enterotoxin, causes pseuodmembrane (inflammation of the membrane)
PSEUDOMEMBRANOUS COLITIS
Clostridium difficile
- characetrized by **mild to moderate diarrhea **
- less severe than Pseudomembranous colitis
ANTIBIOTIC-ASSOCIATED DIARRHEA
in Clostridium difficile, diarrhea may be
WATERY or BLOODY
Clostridium difficile
the very first antibiotics that has been found to cause Psuedomembranous colitis
CLINDAMYCIN
Clostridium difficile | TREATMENT
____ offending antibiotics
discontinue
Clostridium difficile | TREATMENT
new antibiotics that can be administered:
Metronidazole, ____, or
vancomycin
fidaxomicin
Clostridium difficile
a succesful & routine method for the treatment of Pseudomembranus colitis
FECAL TRANSPLANT
- club shaped rods that form metachromatic granules — can store phosphate
- arranged in palusades or in V or L shaped
- forms black colonies on tellurite media
- chinese-letter arrangement of cells Loffler’s serum medium
- 4 biotypes
- aerobic, pleomorphic (shape can vary)
- non motile
Corynebacterium diphtheriae
Corynebacterium diphtheriae
Shape:
club-shaped rods
Corynebacterium diphtheriae
Arrangement:
palusades or in V or L shaped
Corynebacterium diphtheriae
Forms black colonies on what media
tellurite media
Corynebacterium diphtheriae
Chinese-letter arrangement of cells what media
Loffler’s serum medium
Corynebacterium diphtheriae
how many biotypes
4
Corynebacterium diphtheriae
- is a polypeptide with 2 fragments
- heat-labile, single chain
- inhibits protein synthesis by ADP-ribosylation of elongation factor-2 (EF-2)
diphtheria toxin
Corynebacterium diphtheriae
2 fragments of diptheria toxin
fragment A & B
Corynebacterium diphtheriae
diphtheria toxin inhibits protein synthesis by ADP-ribosylation of ____
elongation factor-2 (EF-2)
Corynebacterium diphtheriae
- what fragment allows the entry of toxin
- for binding
fragment B
Corynebacterium diphtheriae | TRUE OR FALSE
all diphtheria had toxin
FALSE
some diphtheria are non toxinogenic
Corynebacterium diphtheriae
where does the diphtheria toxin reside
upper respiratory tract
Corynebacterium diphtheriae
Role of bacteriophage
carries the code for diphtheria toxin
Corynebacterium diphtheriae
acquisition happens in the presence of
bacteriophage
virus-infecting bacteria
bacteriophage
Corynebacterium diphtheriae
- acquired through airborne droplet
- has a chance to be a systemic infection
- a pseudomembrane is formed (commonly over tonsils down to the larynx)
- enlargement of regional lymph node & marked edema in the neck can cause a bull neck appearance
- Mycoarditis (necrosis in heart muscle) accompanied by arrhythmias & circulatory collapse
- nerve weakness or paralysis of the soft palate, eye muscles, or etremities
Respiratory diphtheria
Corynebacterium diphtheriae
Respiratory diphtheria can be acquired through
airborne droplet
Corynebacterium diphtheriae
what is formed in respiratory diphtheria
psueudomembrane
Corynebacterium diphtheriae
common location of pseudomembrane
RESPIRATORY DIPHTHERIA
over tonsils down to the larynx
Corynebacterium diphtheriae
enlargement of regional lymph node & marked edema in the neck can cause what appearance
RESPIRATORY DIPHTHERIA
bull neck appearance
Corynebacterium diphtheriae
- wound or skin diptheria
- a membrane may be formed on an infected wound that fails to heal
- localized infection
- occurs chiefly in tropics
- absorption of toxin is usually slight and the systemic effects are negligible
- matagal mag heal
- does not typically invade deep tissues & practically never enters the bloodstream
CUTANEOUS DIPHTHERIA
Corynebacterium diphtheriae
diphtheria occurs only in persons who possess NO ____
antitoxin antibodis (IgG)
Corynebacterium diphtheriae
antitoxin
Diphtheria antitoix (IM or IV)
Corynebacterium diphtheriae
ANTIMICROBIAL DRUGS
Penicillin
Macrolides
Corynebacterium diphtheriae
Vaccine
Diphtheria toxoid (DPT)
Corynebacterium diphtheriae
Diphtheria toxoid is produced in what animal
horse
Corynebacterium diphtheriae
test that detects the immunity to diphtheria
Schick test
Corynebacterium diphtheriae
Schick test:
check for reaction after how many days
4 - 7 days
Corynebacterium diphtheriae
Schick test:
if there is NO immunity, there will be ____
inflammation
Corynebacterium diphtheriae
Schick test:
if there is immunity, what will be observed
no inflammation
Corynebacterium species are typically ____ (motility) and ____ (catalase)
nonmotile
catalase +
Corynebacterium
grow slowly on sheep blood agar
lipophilic corynebacteria
- a psychotroph
- most common cause of food spoilage in refrigerated environments
- exhibits tumbling end-over-end motility but is temperature dependent (22-28C)
- motile
- β-hemolysis on a blood agar plate
- facultative anaerobe & catalase positive (kaya mag produce ng catalase enzyme)
- had **13 **serovars based on O (seen in cell wall) & H (in flagella) antigens
Listeria monocytogenes
Listeria monocytogenes
Pyschrophile or Psychrotoph?
psychrotoph
Listeria monocytogenes
Motility
tumbling end-over-end motility
Listeria monocytogenes
oxygen requirement
facultative anaerobe
Listeria monocytogenes
catalase
positive
Listeria monocytogenes
temperature needed
22 - 28°C
Listeria monocytogenes
type of hemolysis
β-hemolysis
Listeria monocytogenes
produce β-hemolysis on what type of culture media
blood agar plate
Listeria monocytogenes
how many serovars
13
Listeria monocytogenes
Virulence factors
- Internalins A and B
- Listeriolysin O
- Act A
- Filopods
- Siderophores
I Am Bad Like Omg, Acting lang Filipino kaSi
Listeria monocytogenes | VIRULENCE FACTORS
- has cell wall surface proteins called
- these interact with E-cadherin, a receptor on epithelial cells, promoting phagocytosis into the epitheial cells
internalins A & B
Listeria monocytogenes | VIRULENCE FACTORS
after phagocytosis, the bacterium is enclosed in a phagolysosome, where the low pH activated the bacterium to produce ____
Listeriolysin O
Listeria monocytogenes | VIRULENCE FACTORS
- a listerial surface protein
- induces host cell actin polymerization, which propels them to the cell membrane
Act A
Listeria monocytogenes | VIRULENCE FACTORS
elongated protrusions
Filopods
Listeria monocytogenes | VIRULENCE FACTORS
allows the adherence and entrance of bacteria & will be phagocytized by the phagolysosome
Internalins A & B
Listeria monocytogenes | VIRULENCE FACTORS
environment inside phagolysosome is acidic, allowing the secretion of ____ which punctured the phagolysosome releasing back the bacteria to the cytoplasm & replicated
(cannot be digested anymore kz sira na un phagolysosome)
Listeriolysin O
Listeria monocytogenes | VIRULENCE FACTORS
will propell the organism so that it would move & infect another cell
(itulak sa ibang cell na pede i-infect)
Act A protein
Listeria monocytogenes | VIRULENCE FACTORS
the panunulak of Act A protein will cause the formation of a bubble called
Filopod
Listeria monocytogenes | VIRULENCE FACTORS
steal iron from the cell
Siderophores
Listeria monocytogenes
Transmission
Vertical transmission
across the placenta to the fetus or during dlivery
Listeria monocytogenes
two forms of perinatal human listeriosis
early-onset
late-onset
Listeria monocytogenes | PERINATAL HUMAN LISTERIOSIS
early-onset is also called
garnulomatosis infantseptica
Listeria monocytogenes | PERINATAL HUMAN LISTERIOSIS
- the result of infection in uterus
- a disseminated form of the disease
- characterized by neonatal sepsis (death, overreaction of cells), pustular lesions, and granulomas (nagkakabukol ang organs)
Early-onset syndrome
granulomatosis infantseptica
Listeria monocytogenes | PERINATAL HUMAN LISTERIOSIS
- development of meningitis between birth and the third week of life
- nahawa ang baby during delivery
- mother is asymptomatic or mild influenza-like symptoms
Late-onset syndrome
Listeria monocytogenes | CLINICAL FINDINGS
- mild
- self-limiting; lasting 1-3 days
- incubation period: 6 - 48 hours
- fever, chills, headache, myalgias, abdominal pain, & diarrhea
Gastroenteritis
Listeria monocytogenes
- can develop Listeria meningoencephalitis
- more on brain infections
IMMUNOCOMPROMISED
Listeria monocytogenes
Vaccine
NO vaccine available
Listeria monocytogenes
Antibiotics:
for meningitis & sepsis
Ampicillin w/ or w/o gentamicin
Listeria monocytogenes
Antibiotics:
CNS infections for patients allergic to penicillin
trimethoprim-sulfamethoxazole
- short chains or nonbranching filaments
- disease of animals → erysipelas
- disease of humans → erysipeloid
- madalas nakukuha sa SWINE
- α-hemolytic on blood agar
- catalase negative
- distributed in land & sea animals
Erysipelothrix rhusiopathiae
Erysipelothrix rhusiopathiae
may be α-hemolytic on what type of culture media
blood agar
what is produced when Erysipelothrix is grown on triple sugar iron agar (TSI)
hydrigen sulfide
H2S
what will be the color of TSI when H2S is produced
butt black
Erysipelothrix rhusiopathiae is resistant to what drug
vancomycin
Erysipelothrix rhusiopathiae
- most common E. rhusiopathiae infection in humans
- usually occurs in fingers by direct inoculation at the site of a cut or abrasion
- called as seal finger or whale finger
- incubation: 2-7 days
- lesion is raised, well circumcised, violaceous in color
- pus is not present
- persons with greatest risk: fishermen, fish handlers, bucthers
ERYSIPELOID
Erysipelothrix rhusiopathiae
Treatment of erysipeloid
can resolve without treatment
Erysipelothrix rhusiopathiae
erysipeloid is acquired by
direct inoculation from animals or animal products
Erysipelothrix rhusiopathiae
Rare infections
diffuse cutaneous form
bacteremia w/ or w/o endocarditis
Erysipelothrix rhusiopathiae
drug of choice for erysipeloid
Penicillin G
- coccoid organisms that are modified acid-fast
- salmon pink smooth colonies
- common cause of necrotizing pneumonia
- present in soil & dung of herbivores
- cause disease in cattle, sheep, and swine
- can cause severe pulmonary & extrapulmonary infections in foals
Rhodococcus equi
Rhodococcus equi
modified ____ when stained by Kinyoun method
acid-fast positive
- thin, branching, beaded aerobic bacteria
- filamentous organisms with hyphae-like branching
- weakly acid fast
- opportunistic pathogens
- found in soil & water
- initiated by inhalation
- catalase positive
- produce urease
- cause systemic disease primarily in immunocompromised patients
Nocardia
Nocardia
oxygen requirement
aerobic
Nocardia
component of cell wall
mycolic acid
Nocardia
what type of pathogen
opportunistic
Nocardia
main clinical presentation
Pulmonary nocardiosis
Nocardia
primary route of bacterial exposure
inhalation
Nocardia
associated with most primary cutaneous infections that usually result from trauma
Nocardia brasiliensis
Nocardia
drug of choice
trimethoprim-sulfamethoxazole
Nocardia
species are best identified after recovery on routine media by ____
molecular methods
Nocardia
usual pathologic process
abscess formation
- short or club shaped, long thin, beaded filaments
- branched or unbranched
- aerotolerant
- produce colonies on agar that resemble molar teeth
Actinomyces
Actinomyces
disease
Actinomycosis
Actinomyces
shape
club-shaped
Actinomyces
- a chronic suppurative and granulomatous infection
- produces pyogenic lesions
- inititated by trauma
- causes swelling and may spread to neighboring organs, including bones
Actinomycosis
Actinomyces
- presents as swollen, erythematosus prcoess in the jaw area
- known as lumpy jaw
- mas becomes fluctuant, producing draining fistulas
- disease will extend to contiguous tissue, bone, and lymph nodes of the head & neck
Cervicofacial actinomycosis
Actinomyces
Cervicofacial actinomycosis is also known as
lump jaw
Actinomyces
- symptoms resemble those of a subacute pulmonary infection
- mild fever, cough, and purulent sputum
- lung tissue is destroyed, sinus tracts may erupt, invasion of ribs
Thoracic actinomycosis
Actinomyces
- often follows a ruptured appendix or an ulcer
Abdominal actinomycosis
Actinomyces
- rare occurenece in women
- results from colonization of an intrauterine device with subsequent invasion
Genital actinomycosis
Actinomyces
Treatment
administration of Penicillin for 6-12mos
Actinomyces
drug alternatives
Clindamycin
Erythromycin
- members of normal microbiota
- metabolic products include propionic acid
- highly pleomorphic
- curved, clubbed, or pointed ends; long forms with beaded uneven staining
Cutibacterium
- opportunistic pathogens
- cause the disease acne vulgaris
- produces lipase that split free fatty acids off from skin lipids
- fatty acids can produce tissue inflammation that contributes to acne formation
- cause of postsurgical wounds, particularly those that involve insertion of devices
Cutibacterium acnes
Cutibacterium acnes
disease
acne vulgaris
Cutibacterium acnes
causes acne vulgaris by producing ____
lipases
Cutibacterium acnes is formerly known as
Propionibacterium acnes
Staphylococcus
catalase, coagulase
catalase +, coagulase -
staphylococcus coagulase test
only ____ is positive in the test
S. aureus
only staphyloccocus that is coagulase positive
S. aureus
test for S. epidermidis & S. saprophyticus
novobiocin
STAPHYLOCOCCUS
has resistance in novobiocin
S. saprophyticus
STAPHYLOCOCCUS
susceptible in novobiocin
S. epidermidis
- catalase positive; coagulase negative
- nonmotile
- do not form spores
- grapelike irregular clusters
- slowly ferment carbohydrates, produce lactic acid but not gas
- rapidly develop resistance to any antimicrobial agents
- produce catalase
- resistant to drying & heat
STAPHYLOCCOCI
- major pathogen for humans
- forms golden yellow colonies
- ferments mannitol
- hemolyzes RBC
- halotolerant
Staphylococcus aureus
only staphyloccoci that ferments mannitol
Staphylococcus aureus
Staphylococcus aureus | MECHANISMS OF RESISTANCE
responsible for resistance to many penicillins
β-lactamase
Staphylococcus aureus | MECHANISMS OF RESISTANCE
what causes resistance to penicillins
β-lactam ring
Staphylococcus aureus | MECHANISMS OF RESISTANCE
what causes resistance to nafcillin, methocillin, oxacillin
mecA & mecC genes
Staphylococcus aureus | MECHANISMS OF RESISTANCE
how many types of SCCmec
12
Staphylococcus aureus
HA-MRSA (hospital acquired)
Types I, II III, VI & VIII
Staphylococcus aureus | MECHANISMS OF RESISTANCE
- CA-MRSA (community acquired)
- less resistant, more transmissible
type IV
Staphylococcus aureus | MECGANISMS OF RESISTANCE
partially resistance
Vancomycin-Intermediate S. aureus (VISA)
Staphylococcus aureus | MECGANISMS OF RESISTANCE
completely resistant; encoded by vanA gene
Vancomycin-Resistant S. aureus (VRSA)
Staphylococcus aureus | ANTIGENIC STRUCTURE
- thick polysaccharide polymer
- has endotoxin-like activities
- produce IL-1
- can be a chemoattractant
- can activate complement
PEPTIDOGLYCAN
Staphylococcus aureus | ANTIGENIC STRUCTURE
- polymers of ribotol phosphate
- mediate adherence
- important in cell wall metabolism
- can be antigenic
TEICHOIC ACID
Staphylococcus aureus | ANTIGENIC STRUCTURE
- found in the cell wall of S. aureus
- belongs to group of adhesins called microbial surface components recognizing adhesive matrix molecules (MSCRAMMs)
- binds to Fc fragment of IgG preventing complement activation
PROTEIN A
Staphylococcus aureus | ENZYMES & TOXINS
- produced by staphylococci
- converts hydrogen peroxide into water & oxygen
- positive for staphylococci, negative for streptococci
CATALASE
Staphylococcus aureus | ENZYMES & TOXINS
- an enzyme-like protein that clots oxalated or citrated plasma
- activate prothrombin to form enzyme thrombin
- considered synonymous with invasive pathogenic potential
COAGULASE
Staphylococcus aureus | ENZYMES & TOXINS
- an MSCRAMM
- responsible for the adherence of microorganisms to fibrinogen and fibrin
- induces a strong immunogenic response in the host
CLUMPING FACTOR
Staphylococcus aureus | ENZYMES & TOXINS
regulated by agr
HEMOLYSIN
Staphylococcus aureus | ENZYMES & TOXINS
Hemolysin:
acts on a broad spectrum of eukaryotic cell membranes
α-hemolysin
Staphylococcus aureus | ENZYMES & TOXINS
Hemolysins:
degrades sphingomyelin and therefore is toxic to many kinds of cells including human red blood cells
β-hemolysin
Staphylococcus aureus | ENZYMES & TOXINS
Hemolysins:
* dissociates into subunits in nonionic detergents
* it disrupts biologic mmebranes and may have a role in S. aureus diarrheal diseases
δ-hemolysin
Staphylococcus aureus | ENZYMES & TOXINS
Hemolysins:
* a leukocidin
* lyses white blood cells
γ-hemolysin
Staphylococcus aureus | ENZYMES & TOXINS
- kills WBCs
- important virulence factor in CA-MRSA
Panton-Valentine Leukocidin
Staphylococcus aureus | ENZYMES & TOXINS
- epidermolytic toxin
- dissolve mucopolysaccharide matrix of the epidermis
- toxins are superantigens
EXFOLIATIVE TOXINS
Staphylococcus aureus | ENZYMES & TOXINS
Exfoliative toxin:
* encoded by eta
* located on a phage
* heat stable
* resists boiling for 20 mins
Exfoliative toxin A
Staphylococcus aureus | ENZYMES & TOXINS
Exfoliative toxin:
* plasmid mediated
* heat labile
Exfoliative toxin B
Staphylococcus aureus | ENZYMES & TOXINS
- heat stable
- resistant ot the action of gut enzymes
- cause of food poisoning
- produced when S. aureus grows in carbohydrate & protein foods
- vomiting & diarrhea
ENTEROTOXIN
Staphylococcus aureus | ENZYMES & TOXINS
spreading factor
Hyaluronidase
Staphylococcus aureus | ENZYMES & TOXINS
formation of enzymes
Kinase
S. areus can destroy penicillin through formation of ____
biofilms
Staphylococcus aureus
Clinical findings
nose
skin
vagina
Staphylococcus aureus
Infection from S areus can be
pyogenic
toxin-mediated
Staphylococcus aureus | CLINICAL FINDINGS
- Abscess on foot
- Impetigo
- Folliculitis
- Carbuncle
Skin & soft tissue infections
Staphylococcus aureus | CLINICAL FINDINGS
Skin & soft tissue infections:
* vesicles w/ honey-colored crust
* usually around nose, lips
IMPETIGO
Staphylococcus aureus | CLINICAL FINDINGS
Skin & soft tissue infections:
* multiheaded abscess at the back of the neck
* worst
CARBUNCLE
Staphylococcus aureus | CLINICAL FINDINGS
post-operative wound infections or infections after a trauma (osteomyelitis & meningitis)
Infection from direct contamination of the wound
Staphylococcus aureus | CLINICAL FINDINGS
- Incubation period : 1-8 hours
- nausea, vomiting, diarrhea
- rapid recovery & no fever; no antibiotic needed
Food poisoning (Gastroenteritis)
Staphylococcus aureus | CLINICAL FINDINGS
- vomiting, diarrhea, myalgiad, hypotension w cardiac & renal failure
- often occurs within 5 days after the onset of the menses in young women
- toxin production happens during menstruation
TOXIC SHOCK SYNDROME
Staphylococcus aureus | CLINICAL FINDINGS
- Exofoliative toxin A - heat stable
- B - heat liable
- common in children (esp infants)
scalded skin syndrome
- coagulase negative
- novobocin-sensitive
- pyogenic
- major cause of sepsis
- part of the normal flora of the skin & mucous membrane
- commonly infects IV catheters & prosthetic implants
Staphylococcus epidermidis
Staphylococcus epidermidis
part of the normal flora of the ____ & ____
skin & mucous membrane
Staphylococcus epidermidis
commonly infects ____ & ____
IV catheters & prosthetic implants
- coagulase negative
- causes UTI, particularly in sexually active women
- novobocin-resistance
- pyogenic
- common cause of UTI (1st E. coli, 2nd ____)
Staphylococcus saprophyticus
Staphylococcus saprophyticus
causes ____ particularly in sexually active women
UTI
top 2 common causes of UTI
- E. coli
- S. saphrophyticus
Staphylococcus aureus | TREATMENT
Drug
Penicillin G
Staphylococcus aureus | TREATMENT
Skin infections
Mupurocin
Staphylococcus aureus | TREATMENT
multiple skin infections
Tetracycline
Staphylococcus aureus | TREATMENT
MRSA / NRSA:
drug of choice
Vancomycin
Staphylococcus aureus | TREATMENT
severe infections
Nafcillin
Cloxacillin
Staphylococcus epidermidis | TREATMENT
drug of choice
Dalbavancin
Tedizolid phosphate
Oritavancin
Staphylococcus epidermidis | TREATMENT
- long half life, 300 hours half life
- dosing: once a week (same with dalba)
ORITAVANCIN
Staphylococcus saprophyticus | TREATMENT
drug of choice
trimethoprim-sulfamethoxazole
fluoroquinolone (ciprofloxacin)
both are for UTI
- in chains or in pairs
- widely distributed
- catalase negative
STREPTOCOCCI
STREPTOCOCCI
- partial hemolysis
- Strep pnuemoniae
- Viridans
α-hemolytic
STREPTOCOCCI
- complete hemolysis
- Strep pyogenes
- Agalactiae
β-hemolytic
STREPTOCOCCI
- no hemolysis
- enterococcus
γ-hemolytic
STREPTOCOCCI
GROUP A
Strep. pyogenes
STREPTOCOCCI
Group B
Strep. agalactiae
STREPTOCOCCI
Group A, C, G
Strep. dysgalactiae
STREPTOCOCCI
Group D
Strep. bovis
STREPTOCOCCI
Group F
Strep. anginosus
STREPTOCOCCI | α-hemolytic
- optochin sensitive
- bile soluble
- has capsule
- quellung + (test)
Strep pneumoniae
STREPTOCOCCI | α-hemolytic
- optochin resistance
- bile insoluble
- no capsule
Viridans
STREPTOCOCCI | β-hemolytic
bacitracin sensitive
Strep pyogenes
STREPTOCOCCI | β-hemolytic
bacitracin resistant
Strep agalactiae
- produce capsules
- composed of hyaluronic acid
- cell wall contains proteins
- hairlike pili
Streptococcus pyogenes
Streptococcus pyogenes
capsule is composed of ____
hyaluronic acid
Streptococcus pyogenes
cell wall proteins
M protein
Streptococcus pyogenes
- main virulence factor
- if wala ito, S. pyogenes cannot cause a disease
M PROTEIN
Streptococcus pyogenes | ENZYMES
- dissolves blood clot
- transforms the plasminogen of human plasma into plasmin
STREPTOKINASE
Streptococcus pyogenes | ENZYMES
degrades DNA
DEOXYRIBONUCLEASE
Streptococcus pyogenes | ENZYMES
- spreading factor
- allows the bacteria to spread
HYALURONIDASE
Streptococcus pyogenes | ENZYMES
toxic shock syndrome & scarlet fever
Streptococcal Pyrogenic Exotoxins
SpeA
Streptococcus pyogenes | ENZYMES
Streptolysin O & S
Hemolysin
Streptococcus pyogenes | ENZYMES
- oxygen labile (sensitive to oxygen)
- can trigger antibody production
- colonies grow under the agar
Streptolysin O
Streptococcus pyogenes | ENZYMES
- stable
- not antigenic
- colonies grow on surface of agar
Streptolysin S
Streptococcus pyogenes | PATHOGENESIS
- lesions are raised
- POE: skin
- has well-demarcated line or margin of infection
ERYSIPELAS
Streptococcus pyogenes | PATHOGENESIS
- not raised
- can abot to subcutaneous tissue
- rapidly spreading
- line is indistinct
CELLULITIS
Streptococcus pyogenes | PATHOGENESIS
- flesh eating bacteria
- extensive & very rapidly spreading necrosis
NECROTIZING FASCIITIS
Streptococcus pyogenes | PATHOGENESIS
strep enters the uterus after delivery
PUERPERAL FEVER
Streptococcus pyogenes | PATHOGENESIS
infection of traumatic or surgical wounds
BACTEREMIA or SEPSIS
Streptococcus pyogenes | DISEASES
- most common infection
- caused by β-hemolytic pyogenes
- thin serous discharge & little fever
- cervical lymph nodes are usually enlarged
PHARYNGITIS
Streptococcus pyogenes | DISEASES
- local infection of superficial layers of skin, especially in children
- consists of superficial vesicles that break down and eroded areas whose denuded surface is covered with pus and later is encrusted
- spreads by continuity
- highly communicable, especially in hot, humid climates
IMPETIGO
Poststreptococcal Diseases
- most serious sequela of S. pyogenes
- results in damage to heart muscle & valve
Rheumatic Fever
All S. pyogenes are uniformly susceptible with
Penicillin G
S. pyogenes
alternative drugs for penicillin-allergic patients
Macrolides (Erythromycin& Clindamycin)
- β-hemolytic
- produce zones of hemolysis
- positive to CAMP
- part of the normal vaginal flora and lower gastrointestinal tract of women
- may cause ????
Streptococcus agalactiae
Streptococcus agalactiae
positive for
CAMP test
Streptococcus agalactiae
part of normal ____ in women
vaginal flora
Streptococcus agalactiae
Prevention
IV ampicillin
- α-hemolytic but can also be nonhemolytic
- growth is not inhibited by optochin
- colonies are not soluble in bile
- most prevalent members of the normal microbiota of the upper respiratory tract
- important for the healthy state of mucous membrane in URT
- principal cause of endocarditis on abnormal heart valves
Viridans Streptococci
Viridans Streptococci agalactiae
part of the normal microbiota of ____
upper respiratory tract
Viridans Streptococci agalactiae
may cause ____
endocarditis
Streptococcus pneumoniae
shape
lancet shaped
Streptococcus pneumoniae
positive for
capsule swelling test
quellung reaction
Streptococcus pneumoniae
TYPES OF PNEUMOCOCCI:
adults
type 1 - 8
Streptococcus pneumoniae
TYPES OF PNEUMOCOCCI:
children
types 6, 14, 19, 23
Streptococcus pneumoniae
production of disease
ability to multiply in the tissues
Streptococcus pneumoniae
what drug sila resistant
Penicillin G
Streptococcus pneumoniae | PREVENTION
Children younger than 24 mos
complete series of PCV 7 to PCV 13
Streptococcus pneumoniae | PREVENTION
Older children & those with underlying medical conditions
PCV 7 & single dose of PCV 13
Streptococcus pneumoniae | PREVENTION
Adults 19 y/o or older that are immunocompromised and 65 y/o
PPSV23
PCV13
Enterococci
part of the normal ____ microbiota
enteric
Enterococci
grow in the presence of ____
BILE
Enterococci
hydrolyze ____
esculin
Enterococci
grows in ____ NaCl
6.5%
Enterococci
- most commonly isolated species
- causing 85 - 90% of enterococcal infections
E. faecalis
Enterococci
causes 5 - 10% of entercoccal infections
E. faecium
Enterococci
most common form of enterococcal infection
UTI
Enterococci | INFECTIONS
- often polymicrobial
intraabdominal & pelvic infections
Enterococci | INFECTIONS
frequently associated with metastatic abscess and high mortality rates
bacteremia & endocarditis
Enterococci | INFECTIONS
infections of the respiratory tract
pneumonia, otitis, sinusitis
Enterococci | INFECTIONS
infection of the central nervous system
meningitis
Enterococci | INFECTIONS
can be acquired during vaginal delivery
neonatal infections
Enterococci | TREATMENT
drug of choice
penicillin or vancomycin plus
