Week 2 - Staphylococcus Flashcards
Staphylococcus is a gram ______ cocci arranged in _____-_____ clusters.
positive, grape-like
Staphylococcus
Staphylococcus is a _________ anaerobe.
facultative
Do not require oxygen
Staphylococcus is _____-motile (______-_________).
non, non-flagellated
Staphylococcus is ______-spore forming.
non
Staphylococcus is _______ positive (detoxify ______).
catalase, H2O2
Normally MQ and neutrophils release reactive oxygen species such as hydrogen peroxide. Bacteria have a bullet? against HP = catalase which destroys ROS.
Staphylococcus grows on media containing?
Give an example media.
High salt (>or= to 6.5-10%).
Mannitol SALT agar.
What are the two widely used culture media for growth?
Mannitol salt agar containing high salt (NaCl) concentration (6.5-10%) & Blood agar
Beta
alpha
Gamma
Mannitol salt agar
Mannitol salt agar selectively supports growth of which Gram-positive bacteria?
- Staphlococcus
- Enterococcus
- Listeria
- Micrococcaceae
Mannitol salt agar inhibits the growth of most?
- Gram-negative bacteria
- Streptococcus (gram positive)
S. aureus ferments mannitol and changes the agar color from red to yellow.
S. epidermidis does not ferment manitol and no agar color color change (remains red).
Purple agar base containing 1% of maltose:
1. S. intermedius (left)
2. S. aureus (right; yellow)
3. S. hyicus (bottom)
Staphylococcal spp. classification using unique pigment production on mannitol salt agar and purple agar base with 1% maltose.
Blood agar allows determination of the _____ of _______ toxin produced by the isolates.
type, hemolysin
In addition to growing in the blood media, they are destroying the RBCs.
Alpha = incomplete
Hemolysis = green
Beta = complete
Hemolysis = clear
Gamma = no
Hemolysis = no change in media
Describe what is occurring in the top arrow of this image.
Yellow/golden colony due to a golden
colored carotenoid pigment
staphyloxanthin (it is antioxidant)
any staph with staphy = highly pathogenic
Describe what is going on in the bottom right of this image
Non-hemolysis (gamma) by Staph. epidermidis
Yellow colored Staph. aureus are more ________.
pathogenic
List the methods for diagnosis of Staphylococcus
isolates from suspected cases.
- Gram stain: shape/stain color
- Biochemical tests (biotyping) e.g. hemolysis, catalase, coagulase, and other typing methods
- Molecular biology e.g. PCR of nuc gene
Notes from this slide
1. Put a drop of hydrogen peroxide on glass slide
2. Pick colony
3. Mix
4. If catalase positive, immediately detach hydrogen and oxygen from each other –> bubbles; if bacteria is catalase negative, it simply looks like fluid –> nothing happens, no bubbles.
How do you diagnose staphylococcus by biochemical testing?
Gram stain, catalase are tests that assure you you are dealing with staph.
do blood agar to see if alpha, beta, gamma and coagulase test (e..g serum + colony –> incubate over night; if they are coagulase + = solidify serum; if coagulase - = serum is still in liquid form
_______ ______ strains are more pathogenic particularly strains with _______ _______.
Coagulase positive, beta-hemolysis
How do you classify major pathogenic Staphylococcus species using different tests?
By doing catalase test, you divide staph species into two groups: coag positive and negative
bacteria that coagulate your blood is pathogenic
Blood that hemolyze RBC with beta toxin is pathogenic
coag positive divided into two groups: gamma hemo and beta hemo.
schleiferi pseudo in pets ; know names
coag neg are less pathogenic; know names
notes from this slide
Many in humans that are Coag neg ones that do not clot serum.
Felis, caprae, carnosus = animals
aureus is famous in humans
Staphylococcus sp. is a normal commensal of _____ of mammals and birds, as well as?
skin, reptiles, fish
Staphylococcus normally lives in the ________ orifices of an animal’s body, including:
tubular, Nasal cavity: e.g. 20-40% of the population carry it, Buccal cavity, Naso-pharynx, Mammary gland, Groin region
What percentage of staphylococcus live in the nose of a dog?
31% (16-64%)
What percentage of staphylococcus live in the mouth of a dog?
57% (42-74%)
What percentage of staphylococcus live in the perineum-rectum of a dog?
52% (28-72%)
What percentage of staphylococcus live in the groin of a dog?
23% (16-38%)
What are the major risk factors of Staphylococcal diseases?
- Linked to parasitic, fungi, and viral infections
- Tick (Ixodus ricinus) infestation
- Sarcoptic mange and lice infestation
- Skin vesicles caused by a virus (such as parvovirus or pox virus …)
- Mycotoxin infections - Shearing in sheep
- Hair-cut in dogs
- Nutritional imbalance (zinc, vitamin deficiency)
Staphylococcus is an _________ pathogen.
opportunistic
What are the 3 broad virulence factors for pathogenicity?
Body structures for adhesion and binding, enzymes, toxins
enzymes destroy our CT
Exponential phase - Body structures for adhesion and binding
Stationary phase - enzymes and toxins
Cell wall – useful for bacterial _______, _______, protect the bacteria from attack by host ______.
viability, homeostasis, lysozyme
Protein A - bind ___ of ____ protects, _____ immune response, & ________.
Fc, IgG, blocks, opsonization
Before antibody grabs bacteria, latches on and renders it useless
Binding or clamping factors – attachment to host _______
proteins
Capsule (slime layer) – useful for _______, prevents _______, and inhibits _______ by polymorphonuclear _______.
adhesion, chemotaxis, phagocytosis, leukocytes
Chemotaxis factor won’t be released
Hyaluronidase - breaks down ______ tissue between ______ cells (digs deeper between cells)
connective, adjacent
Catalase – protects against host ______ _______ ______ (____) e.g. H2O2
reactive oxygen species, ROS
Coagulase - _____ blood to hide in it
clots
Staphylokinase - _____ clots (____) to come out of it and disperse _____
lyses, fibrin, itself
Lipase - digest ____, thus allows to colonize _____ surface & ______ glands
lipids, skin, sebaceous
Protease - destroys tissue ______
proteins
Beta-lactamases - _______ beta-lactam drugs’ thus, ______ treatment
inactivate, survive
Hemolysin (alpha, beta, or gamma) - destroys ____ blood cells, ______, _______, _______
red, neutrophils, macrophages, platelets
Cytolytic toxins (leukocidin)- destroy cell _______ of host cells (leukocytes)
membranes
Exfoliative toxin – separate skin ______, resulting in ______ & skin layer _____ _____
layers, impetigo, peel off
Toxic shock syndrome (TSS) toxin – causes
a. ____ &
b. __________ (Mass ___ cell activation i.e. ___% of all body ____ cells)
shock, superantigens, T, 20, T
shock b/c blood not traveling back to heart. superantigens stimulates too many cells –> destroys our tissues
Enterotoxins – ___ toxins in total. They cause
a. food ________ by stimulating the gut _____ (______) &
b. ________
20, poisoning, motility, vomiting, superantigen
Normal antigens activate only _______-_______% of the body’s T cells.
0.0001-0.001
Steps in Staphylococcal pathogenesis starts with entry of _____ of Staphyloccocci by breaching _____ ______
100s, body barriers
Describe the steps of staphylococcus breaching body barriers.
After attach and enter, some turn into biofilm, enter cytoplasm and hide, others are fighting with WBC
Abscess rupture may lead to _______
followed by diverse _____ infection
bacteremia, organ
In cases of abscess rupture, Organs that receive ______ cardiac output are the ______ _____ to get infected. These organs include?
higher, most likely, endocardium, lung, meninges, liver, kidney, uterus, bones, joints
Metastasis is a _____ and/or host immune
status dependent.
serotype,
List the coagulase positive species of Staphylococcus
S. aureus – mammals & birds
S. hyicus – pigs
S. pseudointermedius - pets
S. schleiferi - pets
List the coagulase negative species of Staphylococcus
S. chromogenes – mammals
S. felis – pets
S. epidermidis – foot odor
in humans
due to isovaleric acid production
following degradation of leucine in
sweat by bacterial leucine
dehydrogenase enzyme
Staphylococcus spp. advance from four directions. List these directions
cutaneous pus/abscess, ear, mammary, & urogenital
Staphylococcus spp. advance from four directions to become ?
Systemic & life-threatening infections
bacteremia/septicemia
endocarditis (hear valves)
metritis
pneumonia
osteomyelitis
meningitis
and
life-threatening toxicosis
toxicosis by releasing diverse toxins e.g food poisoning
shock (TSS)
Staphylococcus disease pathogenesis ranges:
from (6) to (5)
Staphylococcus disease pathogenesis ranges:
from scalded skin, pus/abscess, gangrene, ear/otitis,
mastitis, & urogentital infections to pneumonia, endocarditis (heart valves), meningitis, osteomyelitis, & toxicosis/shock
Staphylococcus aureus causes ______ (pus), ______, and _______ first before spreading to cause ?
abscess, dermatitis, mastitis, septicemia, endocarditis, meningitis, & osteoarthritis
What are the broad side effects of Staphylococcus aureus infection?
abscess, septicemia, surgical lesion, infection
What are the side effects of Staphylococcus aureus infection in cattle?
mastitis, teat base pustules/impetigo (>80-90% cases) or gangrenous teat
What are the side effects of Staphylococcus aureus infection in Pigs?
mastitis (impetigo), endometritis
What are the side effects of Staphylococcus aureus infection in Horses?
mastitis, botrymocosis of spermatic cord after castration
What are the side effects of Staphylococcus aureus infection in Sheep?
mastitis similar to cattle, Tick pyemia of lambs, dermatitis of torn skin, periorbital dermatitis
What are the side effects of Staphylococcus aureus infection in Poultry?
septicemia, Foot/joints, pyogranulomatous lesion
= “bumble-foot”, arthritis
What are the side effects of Staphylococcus aureus infection in Goats?
mastitis, Dermatitis, Subacute or peracute mastitis
What are the side effects of Staphylococcus aureus infection in Dogs and Cats?
suppurative lesion similar to S. pseudointermedius
Non- Staph. aureus spp damages what parts of the body?
damage skin, udder, ear,
& eye 1st to spread to lung, urinary bladder, uterus, bones, & joints
S. aureus, S. pedufintermdius (more dangerous than aureus and is more common in pets, S. schleiferi
Staphylococcus species – cause _______ _____, ______ of skin layers, and pus from ____
cutaneous pus, peeling, ears
Staph in humans; peeling of skin; exfoliative
Staph in pigs
Staph in dogs
What is a major sign of staph infection in humans?
Scalded skin
S. aureus infections in humans is characterized by skin layers ______ off; _______ epidermitis)
- widespread formation of _____-filled _____ that are ____ walled and ____ ruptured outer layer or
membrane
- _______ (peeling of skin layers or ______)
due to breakdown of ______ (______ ______)
of skin by _______ exotoxins (______)
slough, exudative, fluid, blisters, thin, easily, exfoliation, desquamation, desmosome, macula adherens, epidermolytic, exfoliatin
What are the signs of S. hyicus infection in pigs?
greasy pig disease (Exudative epidermitis)
(similar to human scalded skin disease)
S. hyicus infection in pigs is characterized by ?
- an acute generalized infection of suckling and weaned pigs.
- excess sebaceous secretion
- exfoliation and exudation of skin
- Poly limb lameness (polyarthritis)
- Metritis
- vaginitis
What two strains of staph can infect pigs?
S. hyicus, S. chromogenes (sometimes)
What are the clinical signs of S. aureus and S. schleiferi in dogs and cats?
Signs: pyoderma of dogs and cats
- erythema, pustule, papule, crust, scaling,
epidermal collarettes, and alopecia;
- cats most commonly present with multiple crusted
papules (“miliary dermatitis”) or erosive plaques
- areas affected in dogs are axillae, groin, ventral
neck, ventral abdomen, interdigital spaces;
- in cats are the face, neck and ventrum
- caused mostly by S. pseudintermedius
What are the clinical signs of S. pseudointermedius and S. aureus in dogs and cats?
- Otittis externa,
- pyoderma,
- Pyometra
What are the clinical signs of S. schlefieri and S. felis in dogs and cats?
Otitis externa
What staph strains lead to clinical signs in dogs and cats?
S. aureus, S. pseuodointermedius, S. schlefieri (less common), S. felis.
Staphylococci - pus and/or gangrene forming
bacteria in the (4)?
skin, udder, joints, wing
Staphylococci
Staphylococci
Staphylococci
Staphylococci
Staphylococci infection in ruminants is characterized by?
Mastitis
- chronic, acute or peracute udder ulcer (impetigo)
- gangrenous mastitis due to a toxin in postparturient cows
- caused by S. aureus
Subclinical ruminant mastitis is caused by what strain of Staph?
S. chromogenes
Of 4 major pathogens of mastitis, >__-___% of mastitis is caused by Staphylococcus
70-80
Mastitis causes loss of ~$__ _____ each year in the
USA alone.
2 billion
What are the four major pathogens that cause mastitis?
- Enterobacteriaceae
- Staph
- Streptococcus
- Mycoplasma
What are the clinical signs of staphylococci in sheep?
Tick pyemia (i.e. the spread in the bloodstream of pus-forming bacteria released from an abscess)
- common in lambs of 2-5 weeks if heavily infested with Ixodes ricinus
- chronic, acute and peracute.
- caused by S. aureus
What are the clinical signs of staphylococci in horses?
Signs: mastitis and skin botryomycosis in horse (botry = cluster of grapes)
- nodules on lips, limbs, scrotum
- multifocal/widespread papules/pustules.
- May have cutaneous and/or visceral involvement
- Scrotum infections after castration in male horses
- caused by S. aureus
What are the clinical signs of staphylococci in poultry?
Signs: Bumble foot in poultry
- A pyogranulomatous process of subcutaneous tissue of foot & the joints
- arthritis and septicemia in turkeys
- omphalitis – yolk sac infection, wing rot or gangrenous dermatitis infection in poultry
- caused by S. aureus
Describe the Isolation and identification methods for
diagnosis of Staphylococcus
Pus sample from skin, nasal sample, blood, etc, milk during mastitis, urogenital during pyometra, joint fluid when there is osteoarthritis; culture on manitol salt agar
How can Staph infections be treated and controlled?
Staphylococcus consists multi-drug resistant species
E.g. Staph. aureus is a member of the 6 gangs (ESKAPE).
•
Staph. aureus is well known globally for acquiring resistance to the following
two antimicrobials
1. Methicillin resistance
2. Vancomycin resistance
find which antimicrobial works (must test to see)
Staph infections can be controlled and prevented by?
Improving hygiene and wellbeing.
Staph infections can be mitigated by
- Improving the _____, ______, and ______ of each animal & its house/barn
- Lambs – _____ control by ____-__ or dipping in ______ periodically
- Proper ______ of wounds and surgical openings
- Carefully perform ______ in sheep, hair-cut in ____
immunity, feeding, hygiene, tick, pour-on, acaricide, cleaning, shearing, dogs
How can you control and prevent Staph infections in dairy animals?
- The fundamental control is good hygiene at milking time.
a. Single use paper towels to dry teats.
b. Milkers should wear gloves.
c. Teat dip after milking (1% Iodine) - Dry cow therapy at drying off.
- Separate all infected/positive cows.
- Cull cows if they remain clinical or cows with chronic mastitis
- Prevent reinfection into the herd.
- Culture to test for positivity all purchased cows before mixing to the herd.
