Exam One Flashcards
Do gram + and gram - have a plasma membrane, periplasmic space, and peptidoglycan?
Yes
Which class of bacteria has a thick peptidoglycan layer?
G +
Which class of bacteria has a outer membrane with LPS
G -
Which class of bacteria has mycolic acid outside of it’s peptidoglycan layer?
Mycobacteria
G- stains/G+ stains (color)
G +: violet/blue
G-: pink
Which class of bacteria’s membrane contains LPS?
G-
How do you measure bacterial growth?
colony counting, turbidimetry, flow cytometry
What is lipid A and how does it work?
Endotoxin, binds to receptor on MO and cytokines and inflammatory factors are released in response.
How can you test for Lipid A?
Limulus Amebocyte Lysate (LAL)
What bacteria don’t contain peptidoglycan?
mycoplasm and chymydia
Which class of bacteria contain teichoic acid on their cell walls?
G +
Which bacteria contribute to acid fast staining due to containing mycolic acid?
Mycobacteria
Flagella are used for?
locomotion/mobility
Fimbriae are used for?
adherence
Endoflagella/axial filaments are present in _______
spirochetes
What are exotoxins?
Produced inside pathogenic bacteria, G +, secreted, A-B toxins, membrane disrupting toxins, superantigens
What are endotoxins?
lipid portion of LPS in G-, liberated when the bacteria die
A-B toxins contain two polypeptides. What does A polypeptide do? Enzyme B?
A: active enzyme, kills the cell
B: binding component, binds to the cell, complete toxin is taken into the cell
What is transformation?
DNA taken up from surroundings
What is transduction?
DNA transferred by virus
What are obligate intracellular pathogens?
rickettsia, chlamydia
What is a facultative intracellular pathogen?
mycobacterium
What is the MIC?
minimum amount of drug required to inhibit bacterial growth. Drugs w/ lower MIC values are better choices.
What are G+ cocci?
Staphylococcus
Streptcoccus
Enterococcus
Micrococcus
Staphylococcus
faculatative anaerobic catalase + cocci
What Staphylococci is associated with Canine Dz?
Staph. pseudintermedius
What causes Greasy Pig Dz?
Staph. hyicus
What causes Sub-acute/Per-Actue mastitis in cows? What causes ulcerative pododermatitis and cervical lymphdenitis in sheep? Bumblefoot? Botryomycosis in rodents etc?
Staph. aureus
Sheep- S. auerus subsp anaerobius
M protein is a virulence factor for ______
Streptococcus
What causes Scarlet fever in humans?
Strep pyogenes
What organism causes Strangles?
Strep. equi subsp equi
What causes Group G strep infections in dogs and cats?
Strep canis
What causes septicemia in pigs and meningitis in humans?
Strep suis
What causes acute fulminating septicemia in fish and has a high zoonotic risk?
Strep. iniae
What causes Jowl Abscess in pigs?
Strep porcinus
What are virulence factors associated with Strep equi?
hyaluronic acid capsule and M protein
Is the G+ rod Rhodococcus a cocci bacteria?
No
What causes septicemic listeriosis in poultry? Which of these is associated with ruminant abortion? CNS form in ruminants
Listeria
Rum Abortion- Listeria ivanovii
CNS- Listeria innocua
Where do facultative intracellular bacteria persist?
macrophages
What are virulence factors for G + rods?
Internalin- adhesion, entry phagocytosis
Listeriolysin O- multiplication, release from phagosome
Act A- intracellular movement
What bacteria can cause circling dz (goats) and unilateral facial nerve paralysis?
Listeriosis
Dz outcome is dependent on
of organisms exposed to
route of exposure
virulence of strain
immune status of host
Erysipelothris rheusiopathiae
none spore forming G+
most common in pigs and birds, zoonotic
Causes Rhomboid shape lesions on
Vegetative endocardiditis in birds
Erysipelothrix tonsillarum
Not virulent in pigs, associated in canine dz
What causes Contagious Bovine Pylonephritis?
Coryrebacterium renale group
C. renale, C. cystiditis, C. pilosum
Corynebacterium stats
Has mycolic acid
g+
fac. anerobe
catalase +
How is Contagious Bovine Polynephritis contracted?
contaminated bedding, venereal transmission, non- sterile OB insturments
risk factors: trauma to bladder and urethra during partrution
What causes Caseous lymphadentitis in sheep and goats? Stats? How is this dz characterized
Corynebacterium pseduotuberculosis
Stats: g+, fac. anaerobe, intracellular cocoobacillus
Characteried: abscess in or near major peripheral lypmh nodes (external form goats) or w/i internal organs and lymph nodes (external form- sheep)
What causes Pigeon Fever/Colorado Strangles/Dry Land Distemper in Horses? Where can it be found? How do horses get it? What does the dz look like?
Nitrogen reducing biotype of C. pseudotuberculosis
Found in Midwestern and Western states
Can enter through skin abrasion or via arthopod vector
Dz: Abcesses in pectoral region/ventral abdomen, ulcerative lymphagitis of lower extremities
What are virulence factors for Corynebacterium?
Exotoxin phospholipase D
damage to endothelial cells and increasing vascular permeability
external lipid coat protects from hydrolytic enzymes
How do you dx Corynebacterium infection?
culture of purulent materials
SHI detects Ab to phosopholipase D endotoxin but you can’t tell if it’s past exposure or current
What causes Murine Pseudotuberculosis?
Corynebacterium Kutscheri
What species does Corynebacterium bovis infect?
Mice
What’s the main causative agent of foal pneumonia?
Rhodococcus equi
Where can Rhodococcus equi be found and what are it’s virulence factors?
Soil, virulence maintained in horses cholesterol oxidase (equi factor) capsule Virulence Associated Proteins (VAPs) (encoded on large plasmids, promotes survival in macrophages) Phospholipase C
How do you screen and dx Rhodococcus equi?
Screen: evaluate premesis, look for elevated plasma fibrinogen, visual inspection, serology NOT reliable
DX: culture or PCR on transtrachel aspirate and cytologic evidence of sepsis, smears
Nocardiosis is caused by what? Stats? What does the dz look like? What’s the main species isolated in dogs and cats?
Nocardia
Pleomorphic, G+, faculatative intracellular, non motile/non spore forming
Dz: mastitis, pneumonia, abcesses, and cutaneus/sq lesions
Main species in dogs and cats N. asteroides
What causes Bovine Farcy? What are the lesions associated with it?
N. asteroides, lymphagitis and lymphaddinitis
Nocardia Dx, Tx, Control
Dx- culture, acid fast
Tx: varies w/ species, aminoglycoside + carbapenum or single tx of timethoprim/sulfa
Control- difficult, dz is sporadic
Do actinomyces, Trueperella, Actinobaculum have mycolic acid?
No
Many antibiotics such as amphotericin, tetracyline, erthymycin, streptomycin, gentomycin are made from this bacteria
Actinomycetes
What’s the biggest cause of pneumonia in cattle?
Trueperella pyogenes
This is a common soil dwelling enviromental saprophyte that produces cell fragments that resemble fungal spores
Actinomycete
What is the habitat of pathogenic species of Actinomyces?
mucosa of oropharynx
What kind of Dz does actinomyces cause?
chronic, progressive, pyogranulomatous (actinomyces grow as colonies in the center)
It’s initiated by disruption of mucosal barrier often from plant material, bite wounds, or oral trauma
Chronic infections cause bone lysis
What causes Pyogranulomatous osteomylitis/lumpy jaw in cattle?
Actinomyces bovis
A hunting dog has a sublumbar abcess, on culture you see a pyogranulomatous lesion with something growing in the center. what do you suspect and how would you dx, tx and control?
Actinomyces hordeovulneris from foxtail
dx: aerobic and anerobic culture
tx- penicillain g long term, sx excision of foriegn body/lesion
control: minimize risk of foriegn bodies
What does Dermatophilus congolenis look like and how can you stain it?
It looks like train tracks
Can stain with Methyline blue (most common) and Giemsa
What causes Rain Scald and Strawberry Footrot?
Dermatophilus congolenis
What species does Dermatophilus congolenis affect and what’s the dz like?
Affects cattle, sheep, goats, and horses (less common pigs, dogs, cats)
Dz: Motile zoospores on moist damaged skin cause epidermal abcesses w/ hyperkeratosis
How would you culture Dermatophilus congolensis?
grows on selective and non-selective blood agar
catalase +, hemolytic carotenoid pigment
Trueperella pyogenes stats
pleomorphic, fac. anaerobe, non-spore forming, non-capsulated, capnophilic
What causes summer mastitis? Is it communicable?
Trueperella pyogenes
Yes, communicable in dairy cattle during dry period
Also causes abortions in cattle
A boar presents with cystitis and polynephritis 3-4 weeks after mating. What caused this?
Actinobaculum suis, anerobic STD,
What is the virulence factor for Actinobaculum suis?
UREASE
Bacillus stats
large G+ rod
endospore forming
Aerboic/fac anaerobe
vary in hemolytic activity
What are the virulence factors for Bacillus anthracis? What is special about them?
capsule
anthrax toxin
Both virulence factors are encoded on plasmids, both are needed for virulence
What’s the McFadyean Txn?
capsule stains w/ a pink shadow w/ polychromatic methyline blue
What 3 factors compose anthrax toxin and what do they do?
Edema- inhibits neutrophils
Lethal- zinc metalloprotease, causes cell death
Protective- cell binding, translocating into cell
What is Wool Sorter’s Dz
Pulmonary inf of Bacillus anthracis in humans
What are some ante-mortem signs of anthrax in cows/horses?
High fever, bleeding from orafices, shock, respiratory distress
What are some post-mortem signs seen in Anthrax?
Dark unclotted blood
incomplete rigor mortis
splenomegaly
What are some characteristics of swine with anthrax?
pharyngeal ulcerative lesions followed by regional lymphadentits
happens after eating contaminated meat and bone meal
Similar for dogs, dogs also get septicemia
How would you dx/tx/control anthrax?
blood smear
aerobic culture and PCR from blood
spleen samples
NO NECROPSY
TX: antimicrobials (penicillan, tetracycline, doxy, cipro)
Control: vx
What causes Tyszzer’s dz in lab animals?
Clostridium piliforme
Clostridium stats
large, endospore forming, G+ rods
What are Clostridium’s virulence factors?
bacterial protein toxins
require anaerobic conditions
necrosis common predisposing factor
What does tetanus cause?
Spastic paralysis
How do you dx Tetanus?
Basically look for a wound and clinical signs
How do you tx Tetanus?
Anti-toxin, Anti-tetanus, Antimicrobial tx, sx debridement, supportive care
What food poisoning neurotoxin bacteria causes symmetrical flaccid paralysis of muscles and eventually death by respiratory failure?
Clostriudium botulinum
Dx C. botulinum
toxin in animal
toxin in food/stomach contents
MALDI TOF
Tx of botulism
IV or IM antitoxin (unbound only)
Drugs that enhance ACH release
Supportive care
Black leg is caused by
Clostridium chauvoei
What does black leg do?
100% fatality in sheep and cattle, emphysemous swelling commonly affecting heavy muscles, myocardium, and diaphram
Black dz/Necrotic Hepatitis is caused by _______
C. novyi type B
C septicum causes
toxemia in all species/ages
exotoxins cause excessive inflammation, resulting in sever edema, necrosis and gangrene
What causes Braxy in sheep? What is Braxy?
C. septicum
Fatal infection w/ toxemia and inflammation of the abomasal wall
Dx of Clostridial necrotic myositis?
DFA (flurenscense)
Tx/Control of necrotic myositis?
penicillin
hyperbaric oxygen
surgical debridement/amputation
vx
C perfingens Type D causes _______
Pulpy kidney dz
How to dx C. perfingens
Culture (toxin genotype)
microscopic appearance
ELISA in dogs
Tx and Control for C. perfingens
hyperimmune serum
Control: vx
What do most infections of Clostridium difficile arise from?
Disruption of natural GI flora (Dybiosis) due to antibiotic use
What does C. dificil Toxin A do? Toxin B?
Toxin A: enterotoxin, fluid loss affect G proteins
Toxin B: cytotoxin, acts synergistically with Tox A
How to dx C. difficile?
Culture- obligate anaerobe, vegetative cells sensitive to handling/tx
Direct toxin detection
Stop antibiotics and avoid anti-diarrheals
What gives Rabbits antibiotic induced diarrhea?
Clostridium spiroforme
How could you culture a non-spore forming anaerobe?
Media enriched with vitamin K, hemin and other growth factors
What is a virulence factor of Fusobacterium necrophorum?
leukotoxin
What are virulence factors of non spore forming anaerobes
catalase and superoxide dismutase
synergistic activities- damage tissue for another organism
Anaerobic infections
Endogenous
Anaerobic
Localized
Mixed/Polymicrobial
Signs in anaerobic infection
Foul smell, gas in tissues, necrosis
Infections not responding to aminoglycosides
What causes foot rot in sheep?
Fusobacterium necrophorum and Dichelobacter nodosus
What causes calf diphtheria- necrotic laryngitis
Fusobacterium necrophorum
How to dx Fusobacterium necrophorum
Culture
Tx: remove necrotic tissue, oxygenate, foot baths, antimicrobials (metronidazole)
How can you ID anaerobes?
MALDI-TOF
Biochem test kits
16s rRNA gene sequencing