MT P1 Flashcards
1
Q
What is the morphology of Staphylococcus?
A
Perfectly spherical, Gram-positive cocci, approximately 0.5 to 1 μm in diameter, grow in clusters resembling a bunch of grapes.
2
Q
What are the two pigmented colony types of Staphylococcus?
A
- S. aureus – golden yellow
- S. epidermidis (formerly S. albus) – white
3
Q
Where does S. aureus primarily inhabit?
A
- Nasal passages
- Skin
- Oral cavity
- Intestinal tract
4
Q
Where does S. epidermidis primarily inhabit?
A
Primarily inhabits the skin.
5
Q
What are the main surface proteins of Staphylococcus that promote colonization?
A
- Facilitate attachment to host proteins such as laminin and fibronectin
- Fibrinogen/fibrin binding (clumping factor)
- Collagen-binding factor
6
Q
What factors inhibit phagocytosis in Staphylococcus?
A
- Capsule
- Immunoglobulin-binding protein A
- Capsular polysaccharide (serotype 5 or 8)
- Protein A
- Leukocidin
7
Q
What is the most potent membrane-damaging toxin produced by Staphylococcus?
A
Alpha Toxin
8
Q
What is the role of Beta Toxin in Staphylococcus infections?
A
Targets membranes rich in sphingomyelin and causes incomplete hot-cold lysis in sheep RBCs.
9
Q
What are superantigens in Staphylococcus, and what do they cause?
A
- Enterotoxins (serotypes A, B, C, D)
- Cause diarrhea and vomiting (staphylococcal food poisoning)
- Can cause toxic shock syndrome (TSS)
10
Q
What is the significance of Toxic Shock Syndrome Toxin (TSST-1)?
A
Responsible for 75% of TSS cases, including menstrual cases.
11
Q
What is the cultural characteristic of S. aureus?
A
Coagulase (+), Catalase (+), ferments mannitol.
12
Q
What is the cultural characteristic of S. epidermidis?
A
Coagulase (-), Catalase (+), does not ferment mannitol.
13
Q
What is the most important coagulase-negative staphylococci (CNS)?
A
Staphylococcus epidermidis
14
Q
What is the main disease caused by S. hyicus subsp. hyicus?
A
Exudative epidermitis (greasy pig disease) in swine.
15
Q
What are the methods used for the diagnosis of Staphylococcus?
A
- Smears
- Culture on blood agar plates (BAP)
- Mannitol salt agar (MSA)
- Coagulase test
- Deoxyribonuclease test
16
Q
What are the antimicrobial resistance mechanisms in Staphylococcus?
A
- Beta-lactamase production
- Methicillin-resistant S. aureus (MRSA) and multi-drug resistant strains
17
Q
What is the morphology of Streptococcus?
A
Gram-positive, non-motile, non-sporeforming, arranged in pairs or chains, capsulated, round to ovoid individual cells.
18
Q
What are the four classifications of Streptococcus?
A
- Sherman Classification
- Lancefield Classification
- Pyogenic
- Viridans
19
Q
What are the main virulence factors of Streptococcus?
A
- Hyaluronic Acid Capsule
- Protein M
- Lipoteichoic Acid
- Extracellular Products
20
Q
What does the CAMP Test indicate in S. agalactiae?
A
Synergistic hemolysis with staphylococcal beta toxin.
21
Q
What is the main disease caused by S. equi?
A
Strangles in horses.
22
Q
What is unique about Clostridium tetani’s morphology?
A
Straight, slender rod with a badminton-racket or drumstick-like appearance due to spore formation.
23
Q
What are the three toxins produced by Clostridium tetani?
A
- Tetanospasmin
- Tetanolysin
- Peripherally active non-spasmogenic toxin
24
Q
What is the pathogenesis of Clostridium tetani?
A
Found in soil, contamination of wounds, especially deep penetrating wounds that become necrotic.
25
How does Tetanospasmin affect the nervous system?
Prevents release of glycine, leading to continuous stimulation and tetanic spasms.
26
What is the primary portal of entry for Clostridium tetani in horses?
Nail wounds.
27
True or False: There is an effective vaccine available for Staphylococcus.
False
28
What are the types of nail wounds in horses?
Nail wounds in horses
29
What procedures are involved in lamb management?
Castration and docking in lambs
30
List some common procedures performed on cattle.
* Calving
* Dehorning
* Castration
* Nose-ringing
31
What is autointoxication?
Autointoxication: A condition where toxins produced within the body (e.g., from bacteria in the gut) accumulate and cause harm.
32
What is a common surgical procedure in swine?
Castration in swine
33
What types of animals can suffer from wound infections?
Dogs and cats
34
What is the significance of the umbilical cord in newborns?
The umbilical cord supplies oxygen and nutrients to the fetus and removes waste. After birth, it should be disinfected to prevent infections like navel ill (omphalitis).
35
Which species are naturally resistant to certain toxins?
Birds – naturally resistant, no antibodies, brain has no affinity
36
What type of antibodies do sheep and goats produce?
Neutralizing antibodies
37
Which animals have variable binding power with toxins?
Horses, dogs, pigs, humans – no antitoxin
38
How much hyperimmune serum from horses is protective?
1,500 units protective for 2-3 weeks
39
What is the composition of vaccines mentioned?
* 0.4% formalin-precipitated
* Aluminum potassium sulfate
* Suspended in saline
40
What is the vaccination schedule for horses?
* Toxoids at 6 to 8-week intervals
* Booster 6-12 months later
* Annual booster
41
What is the recommended treatment for toxin exposure?
* Antitoxin ASAP in a single IV or intracisternal dose of 100,000 to 200,000 units
* Large doses of penicillin
42
What are the key methods for diagnosing toxin exposure?
* Characteristic symptoms
* Drumstick-like spores
* Injection into mice
43
What is Clostridium botulinum known for?
Source of potent neurotoxin causing botulism, characterized by flaccid paralysis and respiratory failure
44
Where was Clostridium botulinum first discovered?
Belgium from imperfectly smoked ham
45
What are the forms of botulism?
* Intoxication
* Wound infection
* Infant botulism (intestinal colonization)
46
Describe the morphology of Clostridium botulinum.
Spores are oval, centric, and excentric
47
What is the major metabolic product of Clostridium botulinum strains?
Acetic acid
48
How do non-proteolytic and proteolytic types of Clostridium botulinum differ?
* Non-proteolytic types acidify but do not coagulate milk
* Proteolytic types slowly curdle milk and partially digest and darken curd
49
What are the serotypes of Clostridium botulinum?
6 serotypes, 7 toxin types
50
What are the strain hosts and diseases caused by Clostridium botulinum?
* A: Humans (Botulism)
* B: Humans, Cattle, Horses, Chickens, Mink (Botulism, Shaker foal syndrome)
* C: Ducks, Wild birds, Humans (Limberneck, Western duck disease)
* D: Cattle (Lamsiekte)
* E, F, G: Humans (Botulism)
51
What is the composition of botulinum toxin?
Complex of toxin molecules and hemagglutinin moiety
52
What is required for full toxic activity of non-proteolytic strains?
Proteolytic enzymes (e.g., trypsin)
53
What type of paralysis does botulinum toxin cause?
Flaccid paralysis progressing to respiratory failure
54
How does the botulinum toxin enter the body?
Ingestion → intestinal wall → bloodstream → peripheral nervous system → flaccid paralysis
55
Which animals are resistant to the botulinum toxin?
Swine and carnivores
56
What is the major cause of necrotizing myositis in horses?
Clostridium perfringens
57
How many types of Clostridium perfringens are there?
Five types (A-E), each producing four major lethal toxins
58
What are the cultural characteristics of Clostridium perfringens?
* Inner zone of complete and outer zone of incomplete hemolysis
* Produces lecithinase (phospholipase C)
* Stormy fermentation of litmus milk
59
What toxin does Type A of Clostridium perfringens produce?
Alpha toxin causes massive intravascular hemolysis and capillary damage
60
What disease does Type B of Clostridium perfringens cause?
Lamb dysentery, hemorrhagic enteritis in sheep and goats
61
List the diseases caused by Type C of Clostridium perfringens.
Enterotoxemia and acute hemorrhagic enteritis in pigs
62
What disease is caused by Type D of Clostridium perfringens?
Pulpy kidney disease (overeating disease)
63
What disease does Type E of Clostridium perfringens cause?
Hemorrhagic, necrotic enteritis in calves
64
How is Bacillus anthracis characterized?
Causes anthrax (Milzbrand in German, Charbon in French)
65
What is the susceptibility of herbivores to Bacillus anthracis?
Herbivores are highly susceptible; carnivores and birds are resistant
66
What is the morphology of Bacillus anthracis?
* Large, Gram-positive rods
* Forms long chains in cultures
* Spores formed at 15-40°C in the presence of air
67
What environmental conditions favor anthrax?
* Alkaline soil with high nitrogen levels
* Alternating periods of rain and drought
* Temperatures above 5.5°C
68
What are the sources of Bacillus anthracis infection?
* Soil
* Bone meal and vegetable protein
* Wool and hair
* Tannery effluents
* Bloodsucking flies and carrion eaters
69
What are the symptoms of anthrax?
* Edema
* Shock
* Hemorrhaging before death
70
What is the peracute form duration of anthrax?
1-2 hours
71
What is the acute form duration of anthrax?
Less than 24 hours
72
What is the diagnosis method for anthrax?
* Blood samples from ear veins
* McFadyean’s stain: organisms stain blue, capsules pink
* Ascoli test: capsular antigen detected via agar gel precipitation
73
What is the immunity status of recovered animals from anthrax?
Recovered animals have permanent immunity
74
What is the causative agent of swine erysipelas?
Erysipelothrix rhusiopathiae
75
What are the forms of disease caused by Erysipelothrix rhusiopathiae?
* Diamond skin disease
* Septicemia
* Polyarthritis
* Endocarditis
* Abortion
76
What is the morphology of Erysipelothrix rhusiopathiae?
* Gram-positive but easily decolorized
* Rough forms exhibit long filaments
* No spores, no flagella
77
What are the routes of infection for Erysipelothrix rhusiopathiae?
* Oral
* Skin scarification
78
What are the acute symptoms of swine erysipelas?
* High fever (41.1°C)
* Deep red patches on skin
* Enlarged and reddened spleen and lymph nodes
79
What type of disease does Erysipelothrix rhusiopathiae cause in humans?
Skin lesions known as erysipeloid
80
What is the protective immunity response for Erysipelothrix rhusiopathiae?
Involves both serum and cell-mediated responses
81
What are the symptoms associated with otic skin infections?
Droopy posture, development of diarrhea, and sudden death
## Footnote
Symptoms may include massive hemorrhages and petechiae in the muscles of the breast and legs.
82
Which animals are highly susceptible to certain diseases?
White mice
## Footnote
Other affected species include crocodiles and bottle-nosed dolphins.
83
What type of immunity is involved in protective immunity?
Both serum and cell-mediated responses
## Footnote
This includes the growth-agglutination test (Wachstumsprobe test).
84
Who developed the first attenuated vaccine?
Pasteur and Thiullier
## Footnote
This vaccine is used for EVA erysipelas.
85
What are the key differentiating symptoms between Hog Cholera and Erysipelas?
Hog Cholera: lethargic, do not eat, diarrhea common, wedge-shaped infarcts present; Erysipelas: bright and alert, continue to eat, diarrhea not common, spleen enlarged, bluish
## Footnote
Other symptoms for Erysipelas include lymph node hemorrhages, petechiae in subserosa, and highly inflamed, dark, bluish stomach.
86
What is the causative agent of human erysipeloid?
E. rhusiopathiae
## Footnote
Human erysipelas is caused by hemolytic streptococci species.
87
What is the only pathogenic species of Listeria to warm-blooded animals and humans?
Listeria monocytogenes
88
Describe the morphology of Listeria monocytogenes.
Gram-positive, non-acid fast, small rods with slight clubbing and diphtheroid appearance
## Footnote
Coccoid forms may also be observed.
89
What are the growth characteristics of Listeria monocytogenes?
Grows on most ordinary media, forms minute points with a narrow zone of beta-hemolysis, and appears bluish-white and transparent on surface colonies
## Footnote
It produces catalase unlike E. rhusiopathiae.
90
What are the two forms of infection for Listeria monocytogenes?
Neural form and visceral form
## Footnote
Neural form involves infection via branches of the trigeminal nerve, while visceral form is primarily through ingestion.
91
What are the main signs of listeriosis in ruminants?
Central nervous system signs include unilateral ataxia and meningitis
## Footnote
Outbreaks often occur in feedlots associated with feeding silage.
92
What is the primary mode of infection for the visceral form of Listeria?
Ingestion
93
How does Listeria monocytogenes escape from the phagosome?
Produces hemolysin listeriolysin O, which lyses cholesterol-containing membranes of eukaryotic cells
## Footnote
This allows the bacteria to escape into the cytoplasm.
94
What is the primary method for isolating Listeria monocytogenes?
Ground brain tissue stored at refrigerator temperature and recultured for up to 12 weeks
## Footnote
It grows well on ordinary media but is routinely isolated on blood agar.
95
What is the main treatment for listeriosis?
Effective antibiotics include chloramphenicol, tetracycline, sulfonamides, and penicillin
## Footnote
In humans, erythromycin and ampicillin are used.
96
What is the type species of Corynebacterium?
Corynebacterium diphtheriae
97
What are the characteristics of Corynebacterium renale?
Most frequently isolated from bovine mastitis, ureteritis, and pyelonephritis; predominantly affects female animals
## Footnote
Causes diphtheritic inflammation of the bladder, ureters, kidneys, and pelvis.
98
What is the main method of transmission for Corynebacterium species?
Contaminated urine droplets
## Footnote
Adherence is pilus-mediated.
99
What is the antibiotic of choice for Corynebacterium infections?
Penicillin in large doses
100
What is Corynebacterium pseudotuberculosis also known as?
C. ovis or Preisz-Nocard bacillus
101
What are the main clinical signs of caseous lymphadenitis?
Suppuration and necrosis of lymph nodes
## Footnote
It is prevalent in sheep and goats.
102
What are the serotypes of Corynebacterium pseudotuberculosis?
Serotype I and Serotype II
## Footnote
Serotype I predominates in sheep and goats, while Serotype II is found in buffalo and cattle.
103
What is the primary disease caused by the genus Eubacterium?
Cystitis and pyelonephritis in sows
104
What is the morphology of Eubacterium?
Pleomorphic, slim, Gram-positive, non-spore forming, non-motile
## Footnote
Exhibits branching and Chinese letter patterns.
105
What is the primary growth condition for Eubacterium?
Optimal growth under anaerobic conditions at 37°C
106
What type of organisms are identified in urine sediment smears?
Gram-positive, slender coryneform organisms
107
What agar media are used for urine aerobic and anaerobic cultures?
Blood agar and CNA agar
108
Which antimicrobial is R. equi sensitive to?
Penicillin
109
To which order does the genus Rhodococcus belong?
Actinomycetales
110
How many species comprise the genus Rhodococcus?
Nine species
111
What characteristic pigment do all species of Rhodococcus produce?
A characteristic red pigment
112
What is the most significant pathogenic species of Rhodococcus in animals?
Rhodococcus equi
113
What was Rhodococcus equi formerly classified as?
Corynebacterium equi
114
What are the bases for the reclassification of R. equi?
Numerical taxonomy, genetics, chemical composition, ecology
115
What morphological forms can R. equi exhibit?
Coccoid and bacillary forms
116
What type of capsule does R. equi possess?
Lamellar polysaccharide capsule
117
What are the colony characteristics of R. equi after 2 days of incubation?
Raised, moist, translucent, regular in outline, initially white then rose pink
118
What biochemical tests are positive for R. equi?
Catalase-positive and urease-positive
119
What is the primary route of transmission for R. equi?
Inhalation of contaminated dust
120
What disease does R. equi cause primarily in foals?
Purulent pneumonia
121
What is the mortality rate associated with R. equi infection in foals?
Can reach 64%
122
What type of immunity plays a critical role against R. equi?
Cell-mediated immunity
123
What is the primary characteristic of the immune response to R. equi?
Poor antibody responses from vaccination
124
What are the main antimicrobial agents R. equi is sensitive to?
Penicillin G, erythromycin, doxycycline, lincomycin, gentamicin, neomycin, streptomycin
125
True or False: R. equi can cause infections in immunocompromised individuals.
True
126
What is the primary pathogenesis of Actinomyces species?
Chronic suppurative infections with granulomatous lesions
127
What unique feature is diagnostic for infections caused by Actinomyces species?
Sulfur granules in exudate
128
What is the primary treatment for Actinomyces infections?
Antimicrobial therapy
129
Actinomyces bovis is known to cause which condition in cattle?
Lumpy jaw
130
What type of lesions does Actinomyces viscosus typically cause?
Abscesses and granulomas
131
What type of bacteria is Actinomyces suis primarily associated with?
Swine
132
What is a common treatment for localized infections caused by Actinomyces?
Iodine-based treatments
133
What is the primary characteristic of Actinomyces pyogenes?
Causes chronic suppurative infections
134
What is the immune response to Actinomyces pyogenes?
Poorly understood; no vaccines developed; relies on antimicrobial therapy.
## Footnote
Actinomyces pyogenes is an opportunistic pathogen, often evading phagocytosis and intracellular killing.
135
What is the antimicrobial susceptibility of Actinomyces pyogenes?
Highly sensitive to:
* Penicillin
* Erythromycin
* Chloramphenicol
Less sensitive to:
* Chlortetracycline
* Streptomycin
Resistant to:
* Polymyxin B
## Footnote
Early-stage lesions respond well to antibiotics, while larger lesions may require surgical excision.
136
What is the morphology of Actinomyces pyogenes?
Small, slender, Gram-positive rods, often slightly curved and clubbed at one end. Can form chains resembling streptococci.
## Footnote
Nonmotile, non-capsulated, and non-acid-fast.
137
Where is Actinomyces pyogenes found?
On mucous membranes of healthy cattle, sheep, goats, and swine.
## Footnote
It is an opportunistic pathogen that invades tissues following wounds or other infections.
138
What diseases are caused by Actinomyces pyogenes?
Causes abscesses in:
* Lungs
* Liver
* Joints
* Reproductive organs
Leads to:
* Mastitis
* Endometritis
* Pyometra
* Septic arthritis
## Footnote
Associated with abortion and periodontal disease in cattle.
139
What is the primary characteristic of the genus Nocardia?
Aerobic, nonmotile, Gram-positive organisms that form mycelial masses fragmenting into bacillary forms.
## Footnote
Most species are soil saprophytes, although some are opportunistic pathogens.
140
What is the cell wall composition of Nocardia species?
Composed of type IV meso-diaminopimelic acid, arabinose, and galactose; contains medium-sized mycolic acids and lipid-soluble nocobactins.
## Footnote
Mycolic acids include LCN-A, a lipid unique to Nocardia.
141
What are the clinically important species of Nocardia?
1. Nocardia farcinica
2. Nocardia asteroides
3. Nocardia caviae
4. Nocardia brasiliensis
## Footnote
Each species has unique pathogenic features.
142
What is the antimicrobial susceptibility of Nocardia farcinica?
Resistant to many antibiotics but may respond to:
* Trimethoprim-sulfamethoxazole
* Amikacin
* Cephalosporins
## Footnote
Infection typically follows wounds or exposure to contaminated environments.
143
What are the cultural features of Nocardia asteroides?
Aerobic growth producing raised, heaped, folded, granular colonies with irregular borders; yellow-orange pigments are common.
## Footnote
Optimal growth occurs at 28–30°C.
144
What type of infections can Nocardia asteroides cause in dogs?
Respiratory infection causing pleural effusion and pyothorax; systemic nocardiosis may cause fever, emaciation, coughing, and neurological signs.
## Footnote
More common in male dogs under 2 years.
145
What is the immunity response to Nocardia species?
Cell-mediated immunity is crucial; sensitized T lymphocytes bind to and kill Nocardia.
## Footnote
B cells play a minor role in immunity.
146
What are the characteristics of Nocardia brasiliensis?
Forms branched, filamentous cells that fragment into bacillary forms; produces yellow to orange colonies on rich media.
## Footnote
Causes mycetoma-like infections in animals and humans.
147
What is the antimicrobial susceptibility of Nocardia brasiliensis?
Sensitive to:
* Trimethoprim-sulfamethoxazole
* Aminoglycosides
* Cephalosporins
## Footnote
Minocycline has shown good efficacy in vitro.
148
Fill in the blank: Nocardia species are primarily found in _______.
soil
## Footnote
Some species are opportunistic pathogens in animals and humans.
