Exam I bacteria Flashcards
1
Q
Actinomyces spp.
A
- Virulence not well understood
- Habitat: mucosa of the oropharynx
- Facutative anaerobic & anaerobic spp. & capnophilic
- Catalase negative
- “molar tooth-like”
- Grow as colonies in center of lesion –> often forms draining tracts
2
Q
What common diseases are caused by Actinomyces spp.?
A
- Pyogranulomatous disease
- Polymicrobial infection within oropharyngeal flora
- Chronic infections –> bone lysis
3
Q
Actinomyces bovis
A
- Causes “Lumpy Jaw” - Pyogranulomatous osteomyelitis
- Gram-positive, club-shaped rods
- Localized, chronic, progressive granulomatous abscess in the mandible, maxillae, or bony tissues in the head
- Introduced via penetrating wounds
- Facial distortions, loose teeth, dyspnea are commonly found
4
Q
Actinomyces bovis diagnosis, treatment and control
A
Diagnosis: culture/microscopic exmanation –> must request aerobic and anerobic cultures
Treatment: Susceptible to penicillin G, iodides; long term treatment; surgical removal of froeign bodies
Control: minimize risk of mechanical injury
5
Q
Dermatophilus congolensis
A
- Epidermal abscesses with hyperkeratosis
- Filamentous branching –> divides into “tram-tracks”
- Aerobic; Catalase positive
- production of coccoid fragments –> motile zoospores
- zoospores have chemotaxis for CO2; attracted to moist and damaged skin
- all animals can be infected: Rain scald in horses; Strawberry footrot in goats; dermatophilosis in reptiles;
Virulence facotrs: chemotaxis of zoospores, keratinolytic activity
6
Q
Dermatophilus congolensis diagnosis, treatment, and control
A
Diagonsis: microscopic examination of scabs; use of Giemsa stain
Treatment: systemic antibitic treatment - penicillin G and tetracycline
Control: Treat and isolate infected invidiausl; eliminate predisposing factors
7
Q
Trueperella pyogenes
What’s the significance in Cattle?
A
- Suppurative infection in ruminant and swine
- Facultative anerobe; non-spore forming; non-motile; non-capsulated; capnophilic
- Found on mucous membranes –> most infections are endogenous
In Cattle: involved in most purulent infection of traumatic/opportunistic origin
- Common location - lung, pericardium, liver, uterus, renal, brain, bones
- Causes: abortion and summer mastitis (communicable disease among pasutred daily cattle during the dry period)
8
Q
Actinobaculum suis
A
- Causes cystitis and pyelonephritis
- Anaerobic; sexually transmitted pathogen
- Commensal diphteroid organism in prepucial mucosa of boars
- Death often follows as a result of renal failure
Virulence factor: UREASE
9
Q
Staphylococcus spp.
A
- Facultative anaerobic; catalase positive; cocci
Exceptions: Anaerobic spp: S. sacharolyticus, S. aureus subsp. anaerobius
- Opportunistic pathogen
- Habitat: Skin and mucous membranes
- Suppurative conditions - production of pus
Toxin mediated diseases (superantigens): Staphylococcal toxic shock syndrome (TSST-1); Staphylococcal food poisoning (enterotoxin); Staphylococcal scalded skin syndrome (Exfoliative toxins)
Virulence factor: Protein A - binds FC portion of IgG; Hemolysins; proteases; hyaluronidase; lipases; leukocidin; biofilm formation
10
Q
What is coagulase? what does it do?
A
Coagulase is an enzyme that is sued to convert fibrinogen to fibrin.
It is often used to differenitate between species
11
Q
Staphylococci pseudintermedius
A
- Most common isolate found in dogs
- Gram positive cocci in clusters
- Cuases pyoderma and folliculitis
Diagnosis:
- Direct examination of species
- Evidence of inflammation with high # neutrophils
- Culture infection
12
Q
Staphylococcus hyicus
A
- Greasy Pig Disease - Exudative epidermitis
13
Q
Staphylococcus aureus
- cattle
- Humans
- Sheep
- Birds
A
Cattle - Chronic and acute mastitis/gangrenous mastitis
Humans - Ulcerative pododermatits
Sheep - Cervical lymphadenitis (subsp. anaerobius)
Birds - Bumble Foot
Rodents, humans, horses - Botryomycosis - Chronic pyogranulomatous inflammation
14
Q
Staphylococcus aureus treatment
A
- Antimicrobial susceptibility testing is essential
- Common emergence of multidrug resistant staphylococci
- inducible Clindamycin resistance in macrolide resistant staphylococcus - isolates which are macrolide resisant is also clindamycin resistant
- Cephalosporins are first line treatment choice –> quinolones are second line
- Beta-lactamase-mediated resistance is common; Methicillin resistance becoming a problem (MRSA (zoonotic) & MRSP)
15
Q
Streptococcus spp.
A
- Gram-positive cocci found in pairs/chains
- Facultative anerobe (aerobic or anaerobic)
- Catalase negative; haemolytic activity used for classification (beta = pyogenic; alpha = non pyogenic)
- Some are capsulated
Diseases:
- Acute suppurative
- Subacute endocardidits
- Chronic mastitis
Superantigens:
- Streptococcal toxic shock syndrdome (STSS)
- Necrotizing fasciitis and myositis (NFM)
16
Q
Streptococcous virulence factors
A
- Capules
- Peptidoglycan layer with teichoic/lipoteichoic acid
- M protien*
- Ig binding proteins
- Streptokinase
- Streptococcal pyrogenic exotoxins (superantigens)
17
Q
Streptococcus pyogenes
A
- Scarlet fever in humans - Rheumatic fever; kidney disease; skin infection; abscesses of the throat; arthritis
18
Q
Streptococcus canis
A
- Commonly infects skin and mucous membranes
- Embolic lesions in heart and lung; septicemia; skin ulcerations; meningitis; necrotizing fasciitis; toxic shock-like syndrome
- Kittens and puppies
19
Q
Streptococcus suis
A
- gram positive cocci
- ZOONOTIC
- Perdominately infection in pigs (type 2 is most common)
- serositis, meningitis, polyarthritis, endocarditis
20
Q
Streptococcus iniae
A
- Infects fish
- zoonotic
- Septicemia in fish; central nervous system disruption
21
Q
Streptococcus procinus
A
Jowl abscess in pigs
22
Q
Streptococcus pneumoniae
A
Humans - Causes pneumonia, septicemia, and meningitis
Guinea pigs and rodents - pneumonia
Domestic pets - act as carriers
23
Q
Streptococcous equi
(S. equi subsp. equi)
A
Strangles in horses!!!
- hyaluronic acid capsule - mucoid appearance
- Use sugar fermentation test to distinguish between different species
- All ages are susceptible, average <2 yrs
- <4 mo are protected by maternal antibodies
- Enlargement of retropharyngeal lymph nodes
- HIGHLY contagious - direct transmission or indirect
24
Q
Streptococcus equi
Virulence factor
A
- Hyaluronic acid capsule
- M Proteins
- IgG Fc binding proteins
- Peptidoglycan/teichoic acid
- Streptokinase
- Hyaluronidase
- Streptolysin
- DNAase
- Exotoxins
25
Streptococcus equi
Clincal signs
- Fever
- Purulent nasal discharge
- Anorexia and dysphagia
- Moist cough
- Lymph node abscessation
- Can survive in pus for 6 - 8 weeks
- Guttural pouch empyema (pus formation)
Bastard strangles - disseminated infection --\> infection of lymph nodes in chest cavity
Purpura haemorrhagica
26
Streptococcus equi
Recovery
Diagnostic
Treatment
Control
Recovery - infected animals usually recover after abscesses mature and rupture
- 75% deelop immunity after recovery
Diagnostic
- Culture
- Serology - ELISA for M protein antibodies
PCR - for M protein
Treatment
- Most recover spontaneously
- symptomatic treatment to relieve pain
- Antibiotics only effective if given soon after exposure
Control
- REPORTABLE DISEASE
- apply isolation, hygiene, and disinfection practice
- Vaccines: Killed --\> effetive for pregnant mares and foals to maintain high level of anti-M protein opsonizing antibodies
- Live --\> similar to killed except in all other animals
27
Enterococcus
- inhibit GI tract
- nosocomial infection
- Causes persistant UTI
- Vancomycin resistance
- In vivo resistance
28
Listeria spp.
- Gram positive facultative anaerobic rods
- capable of growing in a wide range of temperature (4 - 44C) --\> what you find in your fridge!
- Carried in the GI tract of animals
- Outbreaks typically seen after feeding poor-quality silage --\> winter-spring disease as more silage is fed during this time
29
Listeria monocytogenes
- Circling disease - neurologic symptom; unilateral facial nerve paralysis
- Facultative intracellular bacteria --\> persists in macrophages (intracellular growth)
- Outbreak typically occur after feeding poor-quality silage --\> winter-spring disease as more silage is fed during thist time
- Diseases - encephalitis - travels up trigeminal nerve and affects brainstem
- abortions - focal hepatic necrosis
- Septicemia - common in monograstrics
Virulence factors - Internalin (adhesion, entry, phagocytosis)
- Listeriolysin - aids in intracellular multiplication
- Act A - intracellular movement --\> actin filmaent utlized to travel between cells
Lesions:
- Microabscesses and glial nodules infiltrated by neutrophils; acute vascular fibrinoid necrosis; leptomeningitis; neuronal necrosis;
30
Listeria monocytogenes
Diagnosis
Treatment
Control
Diagnosis
- CNS disease
- Circling disease
- Post-mortem - lesions in pons, medullam oblongata, and spinal cord
- Gram stained CSF short intracellular and extracellular gram positive bacteria
Treatment:
- Penicillin, ceftiofur, erythromycin
- high doses are required
Control:
- No vaccines
- Avoid high risk food
- minimize aerosol exposure
31
Erysipelothrix rheusiopathiae
in swine
- Gram-positive facultative anaerobic bacillus
- Non-sporeforming
- swine are the most susceptible (30 - 50% of healthy swine are carriers)
- Causes polyarthritis, vegetative endocarditis, and septicemia
Transmission and virulence factors:
- Primarily oral transmission --\> infection of palatine tonsils
Neuraminidase - adherence to endothelial cells
Heat labile capsule - resistants phagocytosis
32
Erysipelothrix rheusiopathiae
Sheep
Turkey
Marine mammals
Calves
Humans
Sheep - Fibrinopurulent polyarthritis and osteomyelitis
Turkeys - cyanotic combs, splenomegaly, haemorrhage, polyarthritis, endocarditis
Marine mammals - septicemia and similar skin lesions
Calves - polyarthritis
Humans - erysipeloid - localized skin lesions
33
Erysipelothrix diagnosis, treatment, and control
Diagnosis: culture
Treatment: antimicrobia treatment - penicillin & tetracycline
Control: treat and isolate infected animals
- vaccination
34
Bacillus spp.
- Large gram positive rods
- Endospore forming
- Thickpeptidoglycan layer - teichoic and lipo-teichoic acids
- Grows very rapidly
- Aerobic or facultative anerobes
35
Bacillus anthracis
- Koch's postulate is based on anthrax bacilli
- Aerobic, non-motile, square-ended gram positive rods in chains
- non-hemolytic --\> meusa head colonies
- Stains by McFadyean stain
Virulence factors:
- Capsule - polymers of D glutamic acid; produced in vivo
- Anthrax toxin: Edema factor = inhibition of neutrophils; lethal factors = cell death; Protective antigen = translocation into cells
\*\*BOTH FACTORS ARE REQUIRED FOR VIRULENCE\*\*
36
What is the pathogensis of Anthrax
Exposure to endospore --\> endorespores germinate within phagolysosomes of macrophages --\> intracellular survival factors allow growth initiation and phospholipase mediates escape from the phagocytic cell --\> capsule and edema factor inhibit phagocytosis of vegetative cells --\> cells grow rapdily in the body --\> complete anthrax toxin causes cell death and affects vascular permeability
37
What are the different forms of anthrax and what animals are susceptible?
Ruminants - septicemia
Horses - septicemia
Humans - Wool sorter's disease - pulmonary distress
Humans - Cutaneous lesions Q
PIgs and dogs - Pharyngeal lesions
Humans, pigs, and horses - Intestinal lesions
38
What are the pre-mortem and post-mortem signs of antrax baclli in...
Cattle/sheep/deer?
Horses?
Swine?
Carnivores?
Cattle/sheep/deer
Pre-mortem:
High fever; blooding from orifices; shock; respiratory distress
Post-mortem:
Dark and unclotted blood; incomplete rigour mortis; splenomegaly
Horses
- Colic and diarrhea; edema at point of infection
Swine
- Pharyngeal lesions; ulcerative lesion; lymphadenitis; obstructive edema --\> death; ulcerative haemorrhagic enteritis and mesenteric lymphadenitis
Carnivores
- Similar to swine
39
How do you diagnose Anthrax contamination? how do you treat and control it?
REPORTABLE DISEASE
Diagnosis:
- Blood smear exmaination
- Aerobic culture and PCR from blood
- DO NOT CONDUCT FIELD NECROPSY
- Spleen biopsy
- Staining with McFadyean's methylene blue
Treatment
- can only treat vegetative cells
- Antimicrobials - penicillin, tetracycline, doxycycline, ciprofloxacin
Control
- Vaccinate healthy animals
40
Anthrax symptoms/complications in humans
Cutaneous anthrax - subcutaneous edema and septicemia (80 - 90 % recover)
Gastrointestinal anthrax - pharyngeal lesions; lymphadenopathy; vomiting blood and bloody diarrhoea (40 - 75 recover)
Pulmonary or inhalation - pulmonary oedema; pneumonia; meningitis (100% fatality)
41
Corynebacterium spp.
- Gram positive pleomorphic caultative anaerobe rods
- Non-spore forming, non-motile, catalase positive
- Lipophilic spp - Facultative intracellular bacteria
- Non-lipophilic spp - pyogenic toxic
42
Corynebacterium renale
Contagious Bovine Pyelonephritis - inflammation of the kidney
- Disease of adult cows
- Antemortem signs - fever; painful urination; ammoniac odour of urine; acute abdominal pain (colic)
Postmortem signs: Multifocal abscess in kidney; enlarged renal lymph nodes; uremia
43
Corynebacterium pseudotuberculosis
Sheep and Goats
Caseous lymphadenitis
- Effects sheep and goats
- Gram positive facultative intracellular coccobacillus
- Abscess formation in or near major peripheral lymph nodes or within internal organs and lymph nodes
Virulence factor:
- Exotoxin phospholipase D --\> damage to endothelial cells and increasing vascular permeability
- External lipid coat --\> provides protection from hydrolytic enzymes from host
- "onion skin" apperance in the lymph node
Clincal signs:
- Caseous necrosis of lymph nodes
44
Corynebacterium pseudotuberculosis
Horses
Pigeon Fever (Colorado strangles or Dry-lan distemper)
- Cattle can also be infected
- Ucerative lymphangitis of lower extremities
- Abscesses in the pectoral region
- Found in western and midwestern states
- Enter through skin abrasions or arthropod vectors
45
Corynebacterium pseudotuberculosis
Diagnosis
Treatment
Control
Diagnosis:
- Culture of purulent materials
- Synergisitc hemolysin inhibition test (SHI) or you know.. (SHIT) - detects antiboides from phospholipase D exotoxin
- Positive test indicates: past resolved infection, recent exposure, recent vaccination, or active lesions
Treatment:
- Not a "curable" disease
- lancing and draining; surgical excision; systemic antibiotics (penicillin, Rifampin)
Control:
- Biosecurity practice
- Culling of infected animals
46
Corynebacterium kutscheri
- Murine pseudotuberculosis (old world rats!)
- Lung - suppurative pneumonia
- Lesions in kidney, liver, and heart
- Subcuticular abscess
- Lymphoid hyperplasia
47
Corynebacterium bovis
dermatitis in MICE!
hyperkertosis
48
Rhodococcus equi
Foal Pneumonia (1 - 4 month old; rare in \> 8 mo old)
- gram-positive aerobic rods/cocobacilli
- Non-spore forming, non-motile, catalse positive
- Facultative intracellular pathogen
- unique lipid-rich cell envelope structure rich in mycolic acid (acid fast positive)
Virulence factor:
- Capsule
- Virulence associated proteins (VAPs)
- Mycolic acid, teichoic acid/peptidoglycan
- Cholesterol oxidase
- Phospholipase C
Clinical signs:
- Lung - multiple coalescing firm casenecrotic foci
- GI - ulcerative enterocolitis over peyer's patches
Bronchial and mesenteric lymph node - pyogranulomatous lymphadenitis
Bone - Osteomyelitis
49
Rhodococcus equi in..
Cattle
Sheep
Goats
Pigs
Cats
Humans
Cattle - Metritis, lymphadenitis, pneumonia
Sheep - Caseous bronchial lymphadenitis
Goats - Pyogranulomatous lesions in liver and lungs; osteomyelitis of the vertebra and skull; entercolitis
Pigs - Tubercuolosis-like lesions in submaxillary and cervical lymph nodes
Cats - Pyogranulomatous skin lesions
Humans - zoonotic in immunocompromised inidividuals
50
Rhodococcus equi in humans
Lung - Pyogranulomatous pneumonia (alveoli filled with abundant macrophages); septal necrosis and atelectasis
Intestine - pyogranulomatous inflammation of lymphoid tissue
Lymph nodes - pyogranulomatous lymphdenitis
51
Rhodococcus equi
Diagnosis
Treatment
Control
Diagnosis:
- Evalulte the entire premise
- Screen for early detetion of disease
- Serology tests - Culture or PCR on transtracheal aspirate; cytologic evidence of sepsis
- Smears of affected tissue, transtracheal aspirates, bronchoalveolar lavages
Treatment:
- Prolonged treatment --\> expensive and adverse effects
- Combination of macrolide and rifampin
- Hyperimmune plasma and NSAID
Contorl:
- Hyper immune plasma can prevent penumonia
- Early detection, treatment, and environmental management
52
Norcardia asteroides
- Gram positive pleomorphic facultative intracellular bacterium
- Non-motile and non-sporeforming
- Appears as rods, cocci, or coccobacilli --\> long branching filaments
- AEROBIC
- most commonly isolated in species in dogs and cats (more ind ogs than cats)
- Opportunistic, noncontagious, pygranulomatous --\> suppurative disease
53
Norcardia asteroides
Horses
Cattle
Sheep
Swine
Humans
Horses - N. asteroides and N. braziliensis cause fibinopurulent pneumonia and pyothroax
Cattle - Bovine farcy - cutaneous nocardiosis --\> lymphangitis and lymphadenitis
Humans - defects with T cell mediated immunity
Horses, cattle, sheep, and swine - abortions
54
Norcardia asteroides
Diagnosis
Treatment
Control
Diagnosis
- Culture --\> acid fast strain --\> ID
Treatment:
- aminoglycoside + carbapenem
Control:
- Difficult --\> sporadic disease
55
Clostridium spp.
- Neurotoxic - binds to nerves and causes neuronal damage
- Histotoxic and invasive - invade tissues and causes damage
- Enteric/enterotoxigenic - infects the GI tract and produces toxins
Virulence factors:
- All clostridia produce one or more bacterial protein toxins or etracellular enzyme
- Requirement of anaerobic environment = necrosis as a predisposing factor
56
Clostridium tetani
TETANUS - "wooden horse syndrome"
- Anaerobic gram positive Rod
- Terminal endospores --\> grows in contaminated wounds
- Produces neurotoxin --\> spastic paralysis
Pathogensis:
wound infected with C. tetani --\> toxin produced --\> toxins enter nearest motor nerve --\> retrograde transport --\> neuromusclar ending --\> prevents release of neurotransmitters --\> spastic paralysis
57
Clostridium tetani
Diagnosis
Treatment
Control
Diagnosis:
- Culture is often unrewarding --\> takes too long
- Serolog is not very useful
- look for clinical signs: locked jaw + straightened and stiff limbs
Treatment:
- Antitoxin
- Anti-tetanus equine serum (IV or IM)
- Antimicrobial treatment --\> only stops production of toxin
- Supportive care
Control:
- Toxoid immunization
- Post exposure prophylaxis
- Prompt wound management
58
Clostridium botulinum
BOTULISM
- Botulinum neurotoxin --\> inhibits neurotransmitter release
- Food intoxication (vegetable and meats) --\> toxin absorbed and distributed in bloodstream
- Occasional toxico-infectious forms --\> wounds in intestine
- Commonly seen in babies given raw honey --\> honey is a good source of C. botulinum spores
- one gram of dried flesh can have enough botulinum to kill a cow
Clinical signs:
- Symmetrical flaccid paralysis
- Cranial nerve impariment (double vision, dysphagia)
- Hind limb paralysis
- Respiratory failure
HUGE problem in aquatic birds
- Maggots can carry C. botulinum --\> infect aquatic birds during feeding
59
Clostridium botulinum
Diagnosis
Treatment
Control
Diagonsis:
- Demonstration of toxin in serum, food/stomach contents
Treatment:
- IV or IM antitoxin --\> only use if toxin is still being absorbed
- Therapeutic drugs to enchance cholinergic neurotransmitters
Control:
- Toxoid immunization in high risk animals
- Avoid feeding suspected food
60
Features of histotoxic clostridial diseases
- mechanical injury --\> wounds --\> anaerobic environment --\> endospore growth
- Toxins cause tissue destruction --\> fermentation of msucle glycogen --\> gase accumulation
- Deposited endospores may remain dormant in the body for extended periods
61
What is necrotic myositis?
Necrosis of skeletal muscles
62
Clostridum chauvoei
BLACK LEG - Necrotic myositis - emphysematous swelling
- Cattle and sheep
- Lesions appear haemorrhagic
- Sudden death is common (100% fatality) --\> myocardium and diaphragm effected
Clinical signs:
- Fever, anorexia, depression, lameness
63
Clostridum novyi
Spores in intestine and reach liver --\> traumatic damage by liver fluke provides anaerobic conditions --\> germination of spores
64
Clostridium septicum
What does it cause in all species?
What does it cause specfically in sheep?
Malignant edema
- Fatal toxemia affect in all species of animals
- Local exotoxins = inflammation --\> edema, necrosis and gangrene
BRAXY in sheep
- Highly fatal infection
- Toxemia and inflammation of the abomasal wall
65
Clostridium chauvoei, septicum, novyi
Diagnosis
Treatment
Control
Diagnosis:
- Direct fluorescent antibody staining test (DFA)
Treatment:
- antimicrobial treatment (penicillin)
- Hyperbaric oxygen
Control:
- Routine vaccination
66
Clostridium perfringens
Necrotizing haemorrhagic enteritis
- Enteric clostridium
- Five types of toxins - Type D is more commonly found in small ruminants
Type D enterotoxemia - similar symptoms as listeria! - Edema and malacia
67
Clostridium difficile
Enterocolitis
- Affects humans, horses, pigs dogs, cats, laboratory rodents
- Risk factors: recent antibiotic use, increased age, hospitalization
- neonates are resistant
- Dysbiosis - disruption of normal flora --\> pseudomembraneous colitis
Tox A - Enterotoxin, fluid loss
\*Tox B - Cytotoxin, destroys cells rapidly
68
Clostridium difficile
Diagnosis
Treatment
Control
Diagnosis:
- Culture - obligate anaerobe --\> requires anaerobic median
- Direct toxin detection - antigen for Tox A and B
Treatment:
- Stop antibiotics
- Clindamycin should NOT be used in horses
- give probiotics
- avoid anti-diarrhoeal medication --\> accumulates toxin
69
Clostridum spiroforme
- Found in rabbits (4 - 8 weeks old)
- Entertoxemia --\> explosive diarrhoea
- Do not use lincomycin, clindamycin, and erythromycin --\> induces clostridium related enterotoxemia
70
Clostridium piliforme
Tyzzer's Disease
- GRAM NEGATIVE
- Focal liver necrosis --\> fatal diarrheal
71
Non-sporeforming anaerobes
- usually infects mucous membranes and skin
- require high levels of Vit K, hemin, and growth factors
- Endogenous origin
Virulence factors:
- Catalase and superoxide dismutase --\> protection from oxygen
Clinical signs:
- Foul smelling discharge (from necrotic tissue)
- Gas in tissues or discharge
- Pyogranulomatous lesions
- Infetions do NOT repsond to aminoglycosides
72
Fusobacterium necrophorum
Foot Rot and Liver abscess
- Extensive necrosis and keratinolysis in severe cases
Diagnosis:
- Culture and PCR
Treatment:
- Remove necrotic tissue
- Oxygenation
- Antimicrobials (penicillin, metronidazole, clindamycin chloramphenicol, doxycycline)
Control:
- Very difficult
