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18 Cards in this Set
- Front
- Back
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What are the characteristics of Haemophilus? Is it hardy?
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• Small gram negative rods, fermentative
• Motile, facultative anaerobes, no growth on MacConkey • Wimpy- cannot survive outside of _host_ for very long. Culture ASAP after taking sample or freeze in dry ice |
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What is the hallmark of Haemophilus?
How can Staph play a role? |
They require X and V factors
X and V factors! • X = _hemin_ • V = _NAD_ Why Haemophilus won't grow on plain Blood Agar. You need to lyse the RBCs for them. Supplied by _Chocolate_ Agar: heated and lysed RBC/blood agar plates. Staph aureus can be used to release the factors from blood agar- “_Staph_ colonies” - surrounding Staph colonies. |
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Is Haemophilus commensal?
What disease does it cause in the different species? |
Yes
- Cows: septicemia, Thrombomeningoencephalitis (TME), pneumonia – Sheep: genital tract disease – Young pigs: Glasser’s disease – Infectious coryza of chickens: upper RT infection! |
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What is Glasser's Disease?
What bacteria causes it? |
H. parasuis- Glasser’s Disease
• _post-weaning_ pigs: maternal antibodies may be protective- but pathogen is transferred from sow to piglet. • Etiology confusing: May also involve a Strep infection-Similar disease assoc. with mycoplasma • Commensal pathogen that invades the _lower RT_ and can go systemic when animals are stressed • Clinical signs run the spectrum- mild disease, polyserositis, arthritis in chronic form. Peracute form: rapid death can occur. • Control by controlling environmental stresses, perhaps antibiotic prophylaxis. |
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What causes avian coryza or bird colds?
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Haemophilus paragallinarum.
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Is Histophilus somni as fastidious as Haemophilus?
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No
You want to aggressively address this disease Multisystemic disease of cattle and sheep – Respiratory, septicemic, urinary/genital tract! – Shed in urine, semen, oral, nasal.! – Systemic infections associated with capillary blockage • Can lead to secondary infections- Pasteurella, etc. • Disease often occurs rapidly- treatment needs to be aggressive. |
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Histophilus somni is normal flora of the genital and respiratory tracts. What might stimulate them to become pathogenic?
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Rapid shift to cold weather: may predispose animals to disease.
– Stressors “tip the balance”… |
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What are the three forms of histophilus somni?
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_reproductive_ form- can be transmitted sexually
– Death of fetus, abortion • _respiratory_ form-bronchopneumonia _septicemic_ form- bacteria adhere to endothelia |
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What is metaphylaxis?
In what human scenario was this used? |
Timely mass medication of a population to minimize the effects of an expected outbreak.
We used it with the anthrax outbreaks. |
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What kind of dz does Actinobacillus cause in humans? What is special about its toxins?
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Periodontal dz.
Has many hemolysins. |
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What is wooden tongue? How does it manifest in cattle?
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Actinobacillus in cow.
Abscesses in head and throat and under jaw. Lymphatics swell- tongue becomes immovable and not retractable • Abscesses at head end of rumen • Starvation, asphyxiation • Similar disease in sheep- no tongue involvement |
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There are vaccines against actinobacillus, but why would we not want to use it?
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You can't tell the vaccinated animals from the infected animals.
Also, the vaccines are species specific, vs. getting the infxn which, if recovered, protects an animal from the spectrum. Thought to be due to the fact that the vax are killed and not as effective as the live. |
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What vaccine can differentiate between vaccinated and infected animals?
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DIVA vaccines.
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What causes sleepy foal disease? What can this lead to?
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Actinobacillus equuli
Can lead to septicemia. Commensal in genital tract of mares- also oral cavity and GI tract • Foals infected in utero (?) or through the umbilicus after birth- can lead to rapid death of foal • Also- purulent nephritis, arthritis, pneumonia |
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Is actinobacillus suis commensal?
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Yes.
Commensal- infection can lead to disease in piglets • Many tissues can be infected- mortality can be high • Septicaemia, chronic mastitis, pulmonary probs. |
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What does bordetella use filamentous hemagglutinin for?
Does it produce toxins that affect eukaryotic cell cycles? |
Attachment.
Also has pertactin adhesins. Causes cell division by dermonecrotic toxin (DNT) |
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How do Bordetella bronchispetica and atrophic rhinitis work together?
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B. b. colonizes the same tissues in swine as does AR+ P. multicida. Can cause a nonprogressive rhinitis
• Colonization with B.b. predisposes a tissue for infection by P.m. • Prior infection by B.b. also facilitates colonization by other respiratory pathogens – Haemophilus parasuis -Glasser’s disease – Strep. suis- systemic diseases • Note that B. b. produces toxins that impair tracheal physiological defenses |
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What bug is kennel cough?
How does it work? |
Bordetella bronchiseptica
Canine infectious tracheobronchitis – Disease is usually self-limiting, can be complicated in some animals and sometimes by concurrent infections by other pathogens – _ciliastasis_ occurs rapidly after interaction between the pathogen and ciliated cells in upper RT. |
