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Infectious Lecture 4th Year 27-12-2016 Dr.Osamah Muwafk

Diseases associated with Mycoplasma spp.

1.  A class of Gram-negative bacteria
2.  consisting of cells bounded by plasma membrane
3.  Its  organisms  differ  from  other  bacteria  in  that  they  are

deficient in cell walls

4. Mycoplasmas are the smallest prokaryotes with autonomous

replication.

5. They are extracellular parasites with an affinity for mucous

membranes, where they exist as commensals or pathogens

6. Pathogenic mycoplasma have a predilection for the

respiratory system, urogenital tract mammary gland and
serous membrane

7. In general, mycoplasmas are not highly virulent but rather

induce chronic diseases

8. Clinically normal cattle harbor M. bovis in the upper

respiratory tract with no apparent adverse effect

9. may shed the organism through the nasal discharge for

months to years

10. direct contact between infected and susceptible animals is the

primary mode of transmission

11. Calves fed discarded milk from cows with mycoplasma

mastitis may develop pneumonia and otitis media

12. Calves fed discarded milk from cows with mycoplasma

mastitis may develop pneumonia and otitis media

Infectious Lecture 4th Year 27-12-2016 Dr.Osamah Muwafk

CONTAGIOUS BOVINE PLEUROPNEUMONIA

Etiology and Epidemiology:

1. Mycoplasma mycoides subsp. mycoides (Small colony) (M

mmSC)

2. occurs in cattle of the species Bos and allied animals

including buffalo, yak, bison and even reindeer

3. widespread in Africa and occurs in some countries of Asia

and Europe

4. Sporadic outbreaks have been recognized in the Middle East,

probably derived from importation of cattle from Africa

5. morbidity approaches 90%, the case mortality may be as

high as 50% and 25 % of the infected cattle remain as
recovered carriers with or without clinical signs

6. The focus of infection is often provided by recovered

'carrier' animals

7. pulmonary sequestrum preserves a potential source of

organisms for periods as long as 3 years

8. Transmission occurs from direct and repeated contacts

between sick and healthy animals

9. The principal route of infection is by the inhalation of

infective droplets from active or carrier cases of the disease.

10. It is sensitive to all environmental influences, including

disinfectants, heat and drying, and do not ordinarily survive
outside the animal body for more than a few hours

PATHOGENESIS

1. The organism invades the lungs of cattle and causes a

mycoplasmemia

Infectious Lecture 4th Year 27-12-2016 Dr.Osamah Muwafk

2. this results in localization in numerous other sites including

the kidneys and brain

3. resulting in high morbidity and mortality
4. thrombosis in the pulmonary vessels, probably prior to the

development of pneumonic lesions

5. Death results from anoxia and presumably from toxemia

CLINICAL FINDINGS:

A. Acute form

1.  After an incubation period of 3-6 weeks
2.  sudden onset of high fever (40°C; 105°F)
3.  fall  in  milk  yield,  anorexia  and  cessation  of

rumination

4. Coughing, at first only on exercise, and thoracic pain

are evident

5. affected animals are disinclined to move, standing

with the elbows out, the back arched and head
extended

6. Respirations are shallow, rapid and accompanied by

expiratory grunting

7. Pain is evidenced on percussion of the chest.
8. Auscultation reveals pleuritic friction sounds in the

early stages of acute inflammation

9. dullness, fluid sounds and moist gurgling crackles in

the later stages of effusion

10. Dullness of areas of the lung may be detectable on

percussion.

11. Edematous swellings of the throat and dewlap may

occur

12. swelling of the large 'movable joints may be present.

Infectious Lecture 4th Year 27-12-2016 Dr.Osamah Muwafk

13. In calves, valvular endocarditis and myocarditis may

occur

14. In fatal cases death occurs after a variable course of

from several days to 3 weeks

15. In the hyperacute form, affected cattle may die

within 1 week after the onset of respiratory distress

B. Chronic and subacute forms

1. Toxemia and unthriftiness due to inactive sequestrum

in the lung, with a necrotic center of sufficient size

2. a chronic cough, and mild respiratory distress on

exercise

3. These sequestra commonly break down when the

animal is exposed to environmental stress and cause
an acute attack of the disease

CLINICAL PATHOLOGY

1. Isolation or detection of organism
2. The polymerase chain reaction (PCR) has been used to

identify the specific organism and differentiate it from other
members of the cluster

3. Latex agglutination test
4. Serological tests: The complement fixation test (CFT),

ELISA

NECROPSY FINDINGS

1. Lesions are confined to the thoracic cavity and lungs and the

lesions are usually unilateral

2. The pleural cavity may contain large quantities of clear,

yellow-brown fluid containing pieces of fibrin

Infectious Lecture 4th Year 27-12-2016 Dr.Osamah Muwafk

3. Caseous fibrinous deposits are present on the parietal and

visceral surfaces of the lungs

4. The interlobular septae are prominently distended with

ambercolored fluid surrounding distended lymphatics.

5. lobules vary in color with red, gray, or yellow hepatization
6. Consolidation of the lungs with a typically marbled

appearance is characteristic

7. In chronic or advanced cases, a sequestrum of necrotic lung

varying size from 1-10 cm in diameter is surrounded by a
fibrous capsule

8. In affected calves, exudative peritonitis, arthritis, bursitis and

fibrinous arthritis of carpal and tarsal joints may be present

DIFFERENTIAL DIAGNOSIS:

1. Rinderpest erosive: stomatitis, dysentery, and erosions

throughout the alimentary tract

2. Foot and mouth disease: Salivation, lameness, fever, and

vesicular stomatitis

3. Hemorrhagic septicemia: Acute disease with death in 6 to 72

hours. Edema of the neck and brisket, lung lesions similar to
CBPP. Culture of Pasteurella spp.

4. Theileriosis (East Coast fever): Coughing, nasal and ocular

discharge, diarrhea, enlargement of peripheral lymph nodes,
ulceration of abomasum . No lung lesions

5. Ephemeral fever: Ocular discharge, drooling saliva,

lameness,  enlarged  joints,  self-limiting  disease  of  short
duration;  most  affected  cattle  recover  quickly;  fluctuating
fever; secondary pneumonia may occur

Infectious Lecture 4th Year 27-12-2016 Dr.Osamah Muwafk

6. Pulmonary abscesses: Large abscesses containing foul-

smelling purulent material; may have total destruction of
lung

7. Tuberculosis: Tubercular nodules may resemble CBPP

sequestra but they are degenerative cheese-like lesions, often
calcified

8. Farcy: Abscesses of lungs containing foul smelling material

and enlarged local lymph nodes

9. Actinobacillosis: Generalized lesions of lung and other

adjacent tissues

10. Echinococcal (hydatid cysts): Pulmonary cysts with a double

wall and containing clear fluid, often calcified when old

TREATM ENT

1. No therapeutic treatment is effective
2. Antibiotics can alleviate the clinical course of the disease

enabling some improvement in condition

3. Tilmicosin and danafloxacin were effective both in terms of

mycoplasmastatic, and mycoplasmacidal activity

4. Florofenicol and tetracycline were intermediate
5. spectinomycin was ineffective against some strains

CONTROL

The major obstacles to the control and eradication of the disease
are:

1. Difficulty in controlling the movements of cattle, especially

in sub-Sahara Africa

2.  Complications of applying quarantine and slaughter policies
3.  Lack of rapid pen-Side diagnostic tests
4.  Ineffective vaccines

Infectious Lecture 4th Year 27-12-2016 Dr.Osamah Muwafk

5. Insufficient funds to implement control policies
6. Civil strife and drought, which have an effect on the spread

of the disease in Africa.

The possible strategies used for control in affected countries or
regions are:

1.  Slaughter of all sick and in-contact cattle
2.  Slaughter of all sick cattle and vaccination of in-contact cattle
3.  Vaccination  of  healthy  cattle  with  slaughter  of  sick  cattle  in

an epidemic and revaccination of cattle at risk

On a herd basis:

1. Removal of sources of infection
2. Hygiene: Any procedure which brings the animals together

should be avoided

3. Vaccination : Current vaccine strains (T144 and T1SR) for

CBPP are made from freeze dried broth cultures of live
attenuated Mycoplasma mycoides subsp. mycoides SC

Infectious Lecture 4th Year 27-12-2016 Dr.Osamah Muwafk

CONTAGIOUS CAPRINE PLEUROPN EUMONIA

Etiology and Epidemiology

1.  Mycoplasma capricolum subsp. Capripneumoniae
2.  CCPP is one of the most serious fatal diseases of goats
3.  The disease is called Abu Nini in the Sudan
4.  Infectivity is high with a morbidity of 100%
5.  the  illness  is  acute  and  severe  with  a  case  mortality  rate  of

60-100 %

6. transmission by inhalation
7. carrier or infected animal is the source of infection

CLINICAL FINDINGS:

1. Cough, Dyspnea
2. Lagging, lying down a lot (but the animal can stand and

walk)

3. fever (40.5-41Se; 104.5-106°F)
4. in the terminal stages, mouth-breathing, tongue protrusion

and frothy salivation

5. death in two or more days

NECROPSY FINDINGS:

1. hepatization of parts of the lung
2. an increase in pleural fluid with a fibrinous pleuritis

TREATMENT

1. Tylosin tartrate 10 mg/kg BW or oxytetracycline (15

mg/kg/d) is highly successful in limiting the severity of
disease

Infectious Lecture 4th Year 27-12-2016 Dr.Osamah Muwafk

2. The severity of the disease is reduced but treated animals are

still sources of infection

Control :

1. Herd biosecurity to prevent contact with infected animals is

important

2. Vaccination with an inactivated mycoplasma F38
3. A booster dose 1 month after the first vaccination provides

additional protection