Mycoplasma Flashcards
1
Q
What are Mycoplasmas?
A
- Bacteria with no cell wall
- Shapes: rod, coccus, spirallum
- Pleomorphic: ring-shaped, pear-shaped, spiral-shaped, filamentous
- Gram stain poorly
- Special Stains:
- Giemsa
- Castaneda
- Dienes, and more
- Special Stains:
2
Q
What are the General Characteristics of Mycoplasma?
A
- Tiny, obligate Parasite
- Able to pass through 0.22 and 0.45 micron commonly used filters for sterilization of liquid media
- Attach to the Epithelium
- Do NOT survive outside a host
3
Q
What antibiotics are effective against Mycoplasmas?
A
-
Cell Wall inhibitors - Not effective
- Penicillins
-
Protein Synthesis Inhibitors - Effective
- Tetracyclines, tylocin
-
DNA synthesis inhibitors - Effective
- Fluoroquinolones, Baytril
4
Q
What tissues do Mycoplasmas affect?
A
- Primary colonization site is epithelium
- Respiratory Tract
- Joints
- Mammary gland
- Urogenital tract
- Eyes
5
Q
How are mycoplasma transmitted?
A
- Aerosol
- Direct Contact
6
Q
What is the Pathogenicity of Mycoplasmas?
A
- Host Cell attachment
- Membrane associated products such as:
- hemolysins
- proteolytic enzymes
- Urease
- Endonucleases are virulence factor
- Primarily humoral immune response
- Antigenic variation is common
- Infection is associated with tress and other factors (virus, bacteria)
7
Q
How is a Mycoplasma infection diagnosed?
A
-
Culture method (3-10 days)
- Need sterols, vitamins in the media
- Rapid sample collection and culturing
- Cell wall inhibitors used in the media
- Biochemical test have no value
- Histopathology
- Immunofluorescence
- Serology for antibody detection
- Molecular methods -PCR
8
Q
What does Respiratory Disease Caused by Mycoplasma look like?
A
- Affects: Cattle, Small ruminants, Swine, Poultry, Laboratory Rodents and Humans
- Clinically silent and may become chronic
-
Upper respiratory track lesions
- Destruction of respiratory epithelium
- Secondary bacterial or viral infection
9
Q
What Mycoplasma cause Respiratory Disease in Cattle / Sheep / Goats?
A
- M. bovis
- M. dispar
- M. diversum
- M. capricolum ssp. capricolum
- M. capricolum spp. capripneumoniae
10
Q
What Symptoms are found in Respiratory Disease of Cattle / Sheep / Goats?
A
- Pneumonia
- Alveolitis
- Bronchiolitis
- Pleuropneumonia
11
Q
What is the Treatment for Mycoplasma Respiratory Infections?
A
- Oxytetracycline
- Erythromycin
- Tylosin
12
Q
How can Respiratory Mycoplasma infections be prevented?
A
- Strict Biosecurity protocol
- Avoid introducing infected calves to the herd
- Vaccines are not very effective
13
Q
How does Respiratory Disease affect Swine?
A
- Caused by:
- M. hyopneumoniae
- M. hyorhinis
- M. hyosynoviae
- Dry cough
- Worldwide occurrence: 30-70% of hogs
- High economic losses
- Controlled by tiamulin or tylosin therapy, or vaccine
14
Q
How does Respiratory Disease affect Poultry?
A
- Caused by:
- M. gallisepticum
- M. synoviae
- M. meleagridis
- Uncomplicated - low mortality
- Complicated infections: ~30% mortality
- Sinusitis, Air Sacculitis
- Economic losses:
- Downgrading meat
- Loss of egg production
- Medication and mortality
- Economic losses:
- Control by having clean stock, monitoring and removing susceptible flocks
15
Q
What is Bovine Mycoplasmal Mastitis?
A
- M. Bovis and M. californicum
- Bacteria shed in milk, urine, feces, and respiratory secretions
- Transmitted via milking
- Variable clinical signs:
- Acute, Chronic, Sub clinical
- Sudden drop in milk production, rapid involvement of multiple quarters, swelling
- Milk thickness decreases, yellowish, flaky, large clots leaving watery supernate
- Fibrosis: permanent loss of milk production
- Treatment:
- antibiotics are not very effective
- Animals may resolve without intervention
16
Q
How is Bovine Mycoplasmal Mastitis controlled?
A
- Screen newly acquired cows
- Isolate affected animals
- Market severely affected cows
- Return recovered cows to normal milking herd only after 2 negative cultures
- Impose strict hygienic measures
- Do not feed unpasteurized milk to calves
17
Q
What is Bovine Mycoplasmal Arthritis?
A
- Secondary to mastitis
- Primarily caused by M. bovis
- Mortality rate is ~10%
- Affected limbs are held stiff to minimize articular action and pain
18
Q
What is Poultry Mycoplasmal Arthritis?
A
- Caused by M. synoviae
- Lethargy, decreased growth, pale comb, breast blisters, lameness, and joint swelling
- Progresses to chronic stage and may resolve in some cases
- Severe infections in chickens, more than turkeys
19
Q
What is Swine Mycoplasmal Arthritis?
A
- M. hyosynoviae and M. hyorhinis
- Young pigs (6 weeks to 6 months)
- Decreased weight gain and growth
- Exacerbated by stress
- Polyarthritis in young pigs
- May induce respiratory disease
- Tiamulin and Tylosin Therapy
20
Q
What is Bovine Genital Disease?
A
- Four species are involved:
- M. bovis
- M. bovigenitalium
- M. alkalescens
- Ureaplasma diversum
- Abortion and other genital infections
21
Q
What does M. conjunctivae cause?
A
- Keratoconjunctivitis in sheep, goats, cattle, and birds
- Eyes recover in 2-3 weeks
- Control: Good hygienic practices
22
Q
How does Mycoplasma affect canines?
A
- M. edwardi - Upper respiratory tract and genital tract infections
- M. canis
- M. maculosum
- M. spumans from genital tracts
23
Q
How does Mycoplasma affect Felines?
A
- M. felis causes conjunctivitis and pneumonia
- M. feliminutum isolated from oral cavity- Significance
24
Q
How does Mycoplasma affect horses?
A
- M. subdolum - respiratory and genital tracts
- M. equigenitalium - reproductive tract
25
Why is *M. pneumoniae* of public health significance?
* Causes walking pneumonia in humans
* Can also infect oral and genito-urinary tracts
* AIDS and Chemotherapy patients most at risk
