Mycoplasma Species

Front 1

Class Mollicutes

Back 1

-"soft skin": no rigid cell wall
-pathogenic genera: Mycoplasma, Ureaplasma

Front 2

Mycoplasmas general characteristics

Back 2

-smallest prokaryotes
-0.12-0.5 nm
-smallest self replicating organisms
-small genome (0.6Mb)
-reduced metabolic capacity; lack many genes for biosynthesis
-slow growth
-enriched media: require exogenous cholesterol for cell membrane stability

Front 3

Mycoplasmas cell make up

Back 3

-no peptidoglycan in cell wall
-trilaminar plasma membrane (triple layered membrane)
-refractory to many antibiotics: can't treat with penicillin!

Front 4

Mycoplasmas epidemiology

Back 4

-mucus surfaces: conjunctiva, nasal cavity, oropharynx, intestinal and genital tracts of animals
-environment: fragile, don't persist for long periods in environment (because they don't have rigid cell wall)
-last for 3 days in the environment in tropical areas and up to 2 weeks in temperate zone
-host specific

Front 5

Mycoplasmas pathogenesis

Back 5

-no "classic" toxins
-adherence to host cells vital for virulence
-production of ROS (reactive oxygen species)
-capsule
-antigenic variation of surface proteins: immune invasion

Front 6

Mycoplasmas pathogenesis: adherence

Back 6

-needed for colonization of epithelial surfaces
-avoids physical removal by mucociliary activity
-attachment organelle located at bacterial pole serves to localize adhesins

Front 7

Mycoplasmas pathogenesis: production of ROS

Back 7

-leads to tissue damage
-cell lysis, lipid peroxidation, etc.

Front 8

Mycoplasmas pathogenesis: capsule

Back 8

-injection of the MmmSC capsule into calves evokes pulmonary edema

Front 9

pathogenic effects of mycoplasmas

Back 9

Front 10

Diagnosis of mycoplasmas

Back 10

-fresh samples: nasal swabs and/or broncho-alveolar washings (immediate transport, refrigeration, transport medium)
-isolation of bacteria
-FAT, ELISA, or PCR

Front 11

Diagnosis of mycoplasmas: enriched media for isolation

Back 11

-fastidious
-sterol source
-serum and yeast extract
-inhibitors (e.g. penicillin)
-37 degrees C up to 14 days
-fried egg microcolonies (very small: 0.1-0.6mm)

Front 12

Contagious bovine pleuropneumonia (CBPP)

Back 12

-severe contagious disease of cattle
-claimed to have caused more cattle deaths worldwide than any other disease except rinderpest
-caused by MmmSC
-only bacterial OIE (world organisation for animal health) List A disease

Front 13

MmmSC

Back 13

-Mycoplasma mycoides subspecies mycoides Small Colony type
-identifies in 1898 by Nocard and Roux

Front 14

Contagious bovine pleuropneumonia (CBPP): OIE List A disease

Back 14

"potenital for a very serious and rapid spread irrespective of national borders, or serious socio-economic or public health consequence, and of major importance in the international trade of animals and animal products"

Front 15

CBPP: History/evolution

Back 15

-molecular analysis distinguishes 3 main lineages of MmmSC: correlates with their geographical origins
-introduced to South Africa in 1853
-bulls imported from Netherlands
-spread rapidly through cattle production
-contributed to the mid-19th century decimation of the Xhosa people
-present in Northern Africa prior to 1853

Front 16

CBPP: Strains of European origin

Back 16

-not able to oxidize glycerol
-glycerol metabolism linked to H2O2 production
-may account for lower pathogenicity

Front 17

CBPP: distribution
USA, Canada, most of Europe

Back 17

-eradication 19th century
-persistent infection parts of Italy, Spain, Portugal in 1990s
-Portugal officially free 2003

Front 18

CBPP: distribution
Africa

Back 18

-endemic in many sub-Saharan countries (30 countries)
-most important cattle disease in Africa
-2 billion annual losses

Front 19

CBPP: distribution
Asia and South America

Back 19

-problem in China and India
-Never reported in South America

Front 20

CBPP transmission

Back 20

-aerosol spread
-close contact
-incubation 4-6 weeks
-naive cattle populations: up to 50% mortality, close to 100% morbidity

Front 21

CBPP: variation in disease expression

Back 21

-acute, subacute, chronic and unapparent forms
-epidemics: acute cases predominate initially
-as epidemic progresses, sub acute and chronic presentations more frequent
-hence difficult to detect clinical cases of CBPP in endemic areas

Front 22

Acute case of CBPP

Back 22

-characteristic stance: elbows abducted, head extended, arched back
-respiratory distress
-15-20 litres of pleural fluid in chest cavity

Front 23

CBPP port mortem

Back 23

-"marbling" (thickened intralobar septa): subacute lesion
-"sequestra" (fibrotic capsule containing necrotic lung tissue/dead bacteria): chronic lesion

Front 24

CBPP diagnosis

Back 24

-difficult
-herd serology: CFT (compliment fixation test), ELISA
-PCR
-isolation of bacteria: slow

Front 25

CBPP prevention and control: exotic

Back 25

-control imports
-slaughter of affected and in-contact

Front 26

CBPP prevention and control: endemic regions

Back 26

-control animal movement (difficult sub-saharan africa)
-attenuated live vaccine available: not 100% effective, may lead to increases in subclinical infection
-antibiotic treatment not used: illegal in many countries; thought to lead to carrier/subclinical animals and accelerated sequestra development

Front 27

Mycoplasma bovis

Back 27

-pneumonia in calves
-one of the causative agents of "enzootic pneumonia of calves" along with a range of other viruses and bacteria (such as RSV, PI3, M. haemolytica and P. multocida)
-stress as a precipitating factor
-also a cause of mastitis and arthritis
-reservoir and transmission: respiratory tract and milk
-affected cow can shed bacteria in milk

Front 28

Lung of calf with Mycoplasma bovis

Back 28

Front 29

Arthritic joint from calf with Mycoplasma bovis

Back 29

Front 30

Mycoplasma bovis diagnosis

Back 30

-clinical signs and pathological lesions of M. bovis infection are not distinctive
-laboratory diagnosis necessary for identification

Front 31

Mycoplasma bovis diagnosis: individual

Back 31

-isolation of M. bovis: lower respiratory tract (bronchoaveolar lavage)
-immunohistochemistry against Mycoplasma antigen in infected tissue
-PCR

Front 32

Mycoplasma bovis diagnosis: herd

Back 32

-serology: indirect ELISA

Front 33

Mycoplasma bovis treatment and control

Back 33

-pneumonia treatment: prolonged antibiotic therapy (2-3 weeks; tetracyclines)
-no vaccine
-mastitis: cull, no treatment, highly infectious
-pneumonia: improve management and environment

Front 34

Contagious agalactia

Back 34

-M. agalactiae main cause in sheep and goats
-found in Mediterranean, western Asia, North Africa
-infectious
-can be asymptomatic, acute, or chronic

Front 35

Contagious agalactia clinical signs

Back 35

-mastitis
-keratoconjunctivitis
-arthritis
-in lambs and kids: losses due to septicemia and pneumonia

Front 36

Contagious caprine plearopneumonia (CCPP)

Back 36

-M. capricolum subsp capripneumoniae
-one of the most sever diseases in goats
-respiratory disease: extremely contagious and frequently fatal
-naive flocks: morbidity up to 100%, mortality up to 80%
-causes major economic losses in endemic countries (E.g. East Africa and the Middle East)

Front 37

CCPP clinical signs

Back 37

-coughing, labored breathing
-posture
-lesions confined to thoracic cavity

Front 38

CCPP diagnosis and control

Back 38

-diagnosis: culture or PCR (preferred)
-some antibiotics, such as tetracycline, can be effective if given early
-vaccine available: inactive Mccp (provides protection for over 1 year)

Front 39

Atypical pneumonia

Back 39

-M. ovipneumoniae
-sheep and goats
-most commonly isolated mycoplasma from the respiratory tract of normal sheep
-disease linked to intensive management: stress triggers atypical pneumoniae (through inhibition of ciliary activity)

Front 40

Atypical pneumonia: clinical signs and diagnosis

Back 40

-chronic cough
-co-infection with Mannheimia haemolytica produces a more severe pathology
-PCR and ELISA for detection

Front 41

Ovine infectious keratoconjuntivitis

Back 41

-mycoplasma conjunctivae
-lambs: conjunctivitis
-adults: keratitis and corneal ulceration

Front 42

Ovine infectious keratoconjuntivitis: diagnosis and control

Back 42

-PCR or immunoflourescent antibody test (IFAT) on smears
-topical oxytetracycline for treatment (3-4 times/day)
-increase trough space, treat all additions to flock
-widespread throughout UK/Ireland

Front 43

Mycoplasma hypopneumoniae

Back 43

-causes porcine enzootic pneumoniae
-transmission: aerosol, close contact

Front 44

Mycoplasma hypopneumoniae: pathology and clinical signs

Back 44

-M. hyponeumoniae attaches to cilia, causing clumping and destruction
-loss of cilia function: invasion by secondary infections
-persistent dry cough
-loss of weight gain

Front 45

Mycoplasma hypopneumoniae: diagnosis and control

Back 45

-PCR, FAT, serology
-vaccination
-improved ventilation and housing

Front 46

Pig Mycoplasmas

Back 46

Front 47

Mycoplasma diseases of poultry: M. gallisepticum

Back 47

-chronic respiratory disease in chickens
-high morbidity, low mortality
-infectious sinusitis in turkeys
-infection for life
-egg transmission
-mild disease unless secondary invasion by E.coli (increased pathology)

Front 48

Mycoplasma diseases of poultry: M. synoviae

Back 48

-infectious synovitis (inflammation of synovial membrane) in chickens and turkeys
-upper respiratory infection which may become systemic and spread to joints
-infection by contact

Front 49

Mycoplasma diseases of poultry: M. meleagridis

Back 49

-turkeys
-egg transmission and AI
-reduced growth, hatchability, sinusitis, skeletal abnormalities

Front 50

Mycoplasma diseases of poultry: diagnosis and treatment

Back 50

-isolation of pathogen, ELISA, or PCR
-antimicrobials active against Mycoplasma and secondary invaders (e.g. macrolides)
-live vaccine available

Front 51

Mycoplasma diseases of poultry: eradication

Back 51

-improve hygiene and management
-treat breeder layers and eggs
-monitor for infection (seropositives) and cull positives

Front 52

Haemotropic mycoplasmas (aka haemoplasmas)

Back 52

-formerly known as Haemobartonella and Eperythrozoon
-small (<1nm)
-pleomorphic bacteria that attach to RBC of various mammalian species
-until 2000, classified with Rickettsia
-16S rDNA gene sequencing revealed closer relationship to the class Mollicute: reclassified as Mycoplasma

Front 53

Haemotropic mycoplasmas include:

Back 53

-Mycoplasma haemofelis (Haemobartonella felis)
-Mycoplasma haemocanis (Haemobartonella canis)
-Mycoplasma (Eperythrozoon) suis
-Mycoplasma (Eperythrozoon) ovis
-Mycoplasma (Eperythrozoon) wenyonii

Front 54

the haemoplasmas

Back 54

-parasitize erythrocytes: adhere to erythrocyte surface
-coccoidal shape, small <0.9 nm
-cannot cultivate in vitro
-stain well with Romanowsky-type stains: mixtures of methylene blue, azure, and eosin compounds (e.g Giesma)
-transmitted by arthropods
-sensitive to tetracyclines
-resistant to penicillin

Front 55

Mycoplasma (Haemobartonella) haemofelis

Back 55

-feline infectious anaemia (FIA)
-common infection worldwide
-large % population latent carriers

Front 56

Feline infectious anaemia (FIA) tranmission

Back 56

-blood
-biting, fighting (young tom cats)
-intrauterine
-blood transfusion
-biting arthropods

Front 57

Feline infectious anaemia (FIA) clinical signs

Back 57

-immunosuppression/stress precipitates clinical episode
-acute: fever, jaundice, anaemia, splenomegaly
-chronic: weakness, emaciatin, anaemia
-autoimmune attack on the parasitized cells: anaemia
-25-30% mortality
-lifelong carrier status in animals that survive

Front 58

Feline infectious anaemia (FIA) diagnosis and treatment

Back 58

-blood smears over several days (cocci or rods on surface of erythrocytes)
-cyclical bacteremia
-PCR
-haematology: anaemia
-concurrent FeLV or FIV infections: immunosupression worsen the anaemia
-treat with tetracycline