9th lecture • Chlamydiosis • Mycoplasmosis • Coryza • ORT • Anatipestifer disease • Bordetellosis • Clostridial diseases Flashcards
Chlamydiosis
Pathogen
Other names of the disease:
– psittacosis – ornithosis
• Pathogen: Chlamydia psittaci
– 0,2-0,3 μm diameter, round, IC bacterium (difficult
cultivation!)
– different, virulent & less virulent strains
– often detected in the epithelial cell of intestines & respiratory tract
• All avian species are susceptible
– most often turkey, duck
– chicken is less sensitive
– goose in young age mainly
• Infection: with elementary bodies (EB)
– in the organism turn into reticulate bodies (RB)
– replicate in this form after a transient form (intermediate body, IB)
they become elementary bodies again
Chlamydiosis
Pathogenesis
Influential factors: virulence, age, stress, immune status Main feature of the disease: – respiratory lesions – mainly septicaemia – other disease • independent conjunctivitis • independent salpingitis Pathological lesions (septicaemia) – acute splenitis and hepatitis – sero-fibrinous pericarditis, serositis and air sacculitis • mild to severe – acute rhinitis – acute conjunctivitis • often heterophil granulocytic and lymphocytic leptomeningitis – meningitis and/or meningoencephalitis
Chlamydiosis
Diagnosis and Treatment
• Incubation time: 5-10 days • Diagnosis: – Typical clinical symptoms, lesions • swelling above the eye (nasal gland adenitis in turkey) – Serology, IIF, IHC, PCR – Isolation (cell culture) – histopath, lenyomat • Treatment – Prevention (vaccine Ø) – AB – Many countries: • Reportable disease
Mycoplasmosis
Pathogen
Many mycoplasma species
• MG, MS, MM, MI
– In different bird species
– Different diseases
Etiology:
– small (200 nm), bound by single cell membrane
– require complex laboratory background
– no cell wall
• insensitivity to AB degrading cell wall synthesis
• cephalosporins, ß-lactamases
• Other influencing factor:
– Other pathogens (virus, bacteria, fungi, parasites)
– Technopathies, nutritional deficiencies
In chickens: 2 main sp.
– Mycoplasma gallisepticum
– Mycoplasma synoviae
In turkey – Mycoplasma gallisepticum • turkey sinusitis • obligate pathogen – Mycoplasma synoviae – Mycoplasma meleagridis
In geese – Mycoplasma anseris – Mycoplasma cloacale – Acholeplasma laidlawi – M-1220 strain!!!
• In pigeon
– Mycoplasma columbae
Mycoplasmosis pathogenesis
mycoplasma sp. usually colonize in the air ways
– cause mainly respiratory disease
– respiratory mycoplasmosis
• Exemptions…….
– independent conjunctivitis
– independent salpingitis
– infertility caused by mycoplasma living in the
testicles and epididymis
• mycoplasmas are usually facultative pathogens
– Exemption in turkey: turkey sinusitis caused by
Mycoplasma gallisepticum
Mycoplasmosis in chickens
infection:
– vertical (in ovo), horizontal (with respiratory discharge)
– aerogenous, feed and water contaminated with mycoplasma p.o., through the conjunctiva, other ways……
• develops only after predisposing factors!!!
Specific predisposing factors
– Other respiratory pathogens
•IB, infectious laryngotracheitis
• Avian pox, Newcastle disease
• avian metapneumovirus
• vaccine viruses (fe. Newcastle disease)
• Avibacterium, ornithobacterium
Non specific predisposing factors
• overcrowding, bad climate conditions
• transport, grouping, handling the animals
• immunizations, blood sampling
• malnutrition, husbandry problems
Mycoplasmosis caused by M.
gallisepticum in adult age
In layer flocks – serous rhinitis – lacrimation – sneezing – snuffling – sinusitis – drop in egg production + – fertility of the layed eggs decreases Pathological lesions in layer flocks Respiratory lesions…. + • pericarditis, perihepatitis • peritonitis • salpingitis – sero-fibrinous •local complication: pneumonia • In rare cases: – encephalitis, leptomeningitis
• CRD
– Coryza, sneezing, nasal discharge, coughing
– Dyspnoe (open beak)
– growth rate slowed, rate of lay decreases>10-15 egg/hen
• Turkey: uni- or bilateral sinusitis
– prevents birds from opening the eyes
• Lesions:
– Catarrhal inflammation, fibrinous airsacculitis
Mycoplasmosis caused by
Mycoplasma synoviae in chicken
• Infection: as with M. gallisepticum
• Pathogens: they have affinity to synovial membranes!
– some strains have affinity to air ways too!!!
• Two forms exist: the classical and the respiratory
– arthritis, tenosynovitis and bursitis
• appearance:
– in 4-16 week old chicken
• Classic form
– disease of joint, tendon and synovial bursa
• tarsal joints, joints of the toes and the connected tendons
• bursa on the sternal cryst
• Pathological lesions:
– In the above mentioned affexted parts
• serous, sero-fibrinous, sero-purulent
• thick exudate
Mycoplasma melleagridis
Susceptible: turkey airsacculitis, late embrionic death subclinical disease exists – stunting, abnormal feathering, bone deformity – reduced hatchability
Mycoplasma iowae
Susceptible: turkey
– Late embrionic death (between dd 18-24, 5-20%)
• Lesions:
– embryos are small, congested, edematous, hepatitis
– groth retardation, feather abnormalities, leg deformities
– airsacculitis
Mycoplasma melleagridis
Mycoplasma iowae
• Diagnosis – Special laboratory conditions – identification of colonies (PCR) – serology • Treatment – eradication • biosecurity • vaccination • maybe AB in breeder flocks
Infectious coryza
Pathogen
• Haemophilus infection of chickens (+pheasant and guinea fowl)
• Pathogen:
– Avibacterium (Haemophilus) paragallinarum
– different serotypes (A, B, C)
– virulent and less virulent strains
– Av. avium, Av. endocarditis, Av. gallinarum
• disease of broilers and adults (but in every age)
• not often seen, but…
– causes multitudinous disease
– spreads rapidly
– main feature:
• sero-fibrinous inflammation of the upper respiratory airways
Infectious coryza • Pathogenesis:
• Spreading:
– Carrier birds (nasal discharge, feces)
• Infection:
– direct contact
– aerosol (through air ways)
– feed/ water contaminated with nasal discharge
• Pathogenesis:
– the pathogen replicates in the air ways• conjunctiva, nasal cavity, trachea
– at the beginning the discharge is serous
– later sero-fibrinous exudate occurs
– fills the nasal cavity too • get stuck there
– incubation period: 1-3 days
– mainly in 8-12 week-old age group
– spreads rapidly
– almost all animals get sick
• Clinical signs:
• at the beginning (in acute phase)
– nasal discharge
– drowsiness because of fever
– lack of appetite
– conjuctivits, lacrimation, oedema of the head
– delayed start of egg production or severly reduced (10-40%)
• scary clinical symptoms, low mortality
– the discharge becomes thick• fibrinous consistency –sinuses appear dilated – edema & cyanosis of the eyelids, appendixes of the head appear swollen, bluish-red – sneezing, snuffling Infectious coryza
– Chronic case • abnormal destruction of the stagnated inflammatory exudate • sweet-smelly odor in the stable – complications: • mycoplasmosis • respiratory inflammation by Pasteurella sp.
Infectious coryza
Diagnosis & Treatment
diagnosis: – epidemiology of the disease – clinical signs – upper respiratory symptoms – Isolation of the pathogen from nasal discharge – PCR • Treatments – „All in/all out”, vaccination, AB medicated water and/or feed
Ornithobacteriosis
Pathogen
• Ornithobacterium rhinotracheale – Gram -, non-ciliated, pleomorph – resistance: low – optionally pathogenous • different 18 serotypes are known (A-R) – frequent serotypes: A, B, D, E – in hens: in 54% of the cases type A infection • It was identified at the beginning of the ‘90s – new taxon – frequent in Hungary • belongs to the normal flora– in chicken and turkey • Infection – horizontal • aerosol, contaminated water/feed – vertical (?) • the pathogen was found in oviduct, egg or embryo
