The Genus Mycoplasma and Bovine Mycoplasmas Flashcards
Where do Mycoplasmas generally reside?
on host non-enteric mucosal surfaces
In general, what diseases do Mycoplasmas produce?
diseases that spread slowly and produce little or no mortality but there are exceptions
What class does Mycoplasma belong in?
Mollicutes
What genera are recognized in the class Mollicutes as important in gene production?
Mycoplasma and Ureaplasma
True or False - Mycoplasma is the largest living structure capable of growth in cell-free medium.
false - it’s the smallest
What is special about the cell wall of Mycoplasma?
it doesn’t have one - the outer layer of mycoplasmas is analogous to the inner cell membrane of other bacteria
Why are Mycoplasmas resistant to penicillin?
because they do not synthesize peptidoglycan
What is the morphology of Mycoplasma?
pleomorphic, coccoid to filamentous, often pear-shaped, faintly gram-negative, and usually non motile
What colonies of Mycoplasmas look like?
small and have a characteristic fried egg appearance due to growth of the center of the colonies down to the medium
What genus does Mycoplasma share an anscestor with?
Clostridia
In normal animals, where do mycoplasma live?
mucous membrane surfaces of the respiratory tract, eyes, urogenital tract, mouth, and mammary glands
In disease, where are mycoplasmas found?
lungs, conjunctiva, urethra, mammary glands, joints, serosal surfaces, and the brain
What are the optimal growth conditions for Mycoplasmas?
Ph: 7-8, high humidity, and increased CO2
What are some other characteristics of Mycoplasmas?
Immunosuppression, specialized attachment to host cells, hemolysis, ammonia, antigenic shift, and super antigens
What antimicrobials are routinely used to treat Mycoplasmas?
Linomycin and tylocin, tilmicosin, tulathromycin, zuprevo, tetracyclines, and tiamulin
What is the best way to prevent Mycoplasmas?
immunization
What are the common bovine mycoplasmas?
Mycoplasma mycoides subspcies mycoides SC, Mycoplasma bovis, Mycoplasma bovoculi, Mycoplasma dispar, Ureplasma diversum, Mycoplasma bovigenitalium
What is Mycoplasma mycoides subspecies mycoides SC the cause of?
contagious bovine pleuropneumonia (CBPP)
Where is Mycoplasma mycoides subspecies mycoides SC endemic to?
most of Africa and parts of Asia (India and China)
How is Mycoplasma mycoides subspecies mycoides SC transmitted?
by droplet, aerosol, and contact - primarily by inhilation
Mycoplasma mycoides subspecies mycoides SC primarily effects cattle, what other species can it affect?
buffalo, yak, reindeer, and bison
What tissues is bronchopneumonia caused by Mycoplasma mycoides subspecies mycoides SC limited to?
lungs with involvement of intrapulmonary lymphatics and thoracic lymph nodes
How is Mycoplasma mycoides subspecies mycoides SC diagnosed?
PCR testing, isolation, and CF test
What is the best preventative measure for Mycoplasma mycoides subspecies mycoides SC?
elimination of infected herds where possible
What immunization is given for Mycoplasma mycoides subspecies mycoides SC?
avirulent strains given intranasally
How do you treat Mycoplasma mycoides subspecies mycoides SC?
tetracylcines - but it is discouraged because the organism is only suppressed and chronic carriers result
What is the most serious Mycoplasma of cattle in countries where Mycoplasma mycoides subspecies mycoides SC is not present?
Mycoplasma bovis
How is Mycoplasma bovis transmitted?
by droplet, contact, direct contamination of the mammary gland or through milk or colostrum, and semen
What are the msot common disease processes associated with Mycoplasma bovis?
mastitis, pneumonia, otitis, and polyarthritis
What is Mycoplasma bovis occasionally involved in?
abortion, subcutaneous abcesses, and meningitis
What toxin does Mycoplasma bovis produce and what is its function?
a glycoprotein toxin that produces inflammation in mammary tissue and may include necrosis of lung tissue
How are cattle with Mycoplasma bovis treated?
they aren’t - they are usually culled or at least segregated from the rest of the herd until they can be culled
How is Mycoplasma bovis prevented?
pasteurization and immunization
Is immunization against Mycoplasma bovis effective?
yes for the respiratory infection and mastitis but it does not provide solid immunity
What infection does Mycoplasma bovoculi predispose for?
Moraxella bovis which produces pink eye
What diseases does Mycoplasma dispar cause?
pneumonia in calves
Where is Mycoplasma dispar commonly found?
in the respiratory tract
How long does the infection from Mycoplasma dispar usually last?
2-5 months
Mycoplasma dispar results in suprression of antibody response to __________ _______-.
Mycoplasma bovis
What appears to be important to the development of Mycoplasma dispar?
hypersensitivity
What disease has Ureaplasma diversum been incriminated in causing?
granular vulvo-vaginitis and infertility in cows
Recently Ureaplasma diversum has been revealed to be the major cause of what in cattle?
abortion
How does disease from Ureaplasma diversum occur?
new strains are entered into the herd because this organism is found in nasal passages and the vulvovaginal tract and in the prepuce and semen of males
What disease processes have been associated with Ureaplasma diversum?
abortions, severe erosive and pitting arthritis with synovitis, pneumonia in calves, and conjunctivitis
Where does arthritis and synovitis due to Ureaplasma diversum typically effect?
stifles, hips, and shoulders
How is Ureaplasma diversum diagnosed?
PCR on placenta, abomasal contents, and fetal tissue along with gross or histologic lesions
What diseases processes can Mycoplasma bovigenitalium cause?
seminial vesiculitis, epididymitis, orchitis, and urethritis
What is Mycoplasma bovigenitalium a common contaminant of?
semen
What has Mycoplasma bovigenitalium been isolated from?
Mastitis cases
