Post on 26-Mar-2018
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Mycoplasmas, Ureaplasmas & Haemoplasmas
Illustration by David S. Goodsell, the Scripps Research Institute
Week 4, Lecture 20: PJL
Mycoplasma Group: Overview Facultative anaerobes, stain poorly
Tiny cell (0.3 – 0.8 um)
Trilaminar plasma membrane Lipoprotein & phospholipid
No peptidoglycan layer β-lactams – Penicillins & Cephalosporins
highly pleomorphic
Closely related to Streptococcus Cannot synthesize cholesterol
Infections are varied: Respiratory (Upper & Lower Resp. Tract)
Mastitis
Arthritis, Chondropathy, Otitis media
Urogenital tract infections
Week 4, Lecture 20: PJL
Transmission Electron Microscope
Scanning Electron Microscope
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Mycoplasma Group: Virulence
Highly host-adapted: prolonged carrier states Epi/Intracellular association
Insidious infections – chronicity
No LPS-endotoxin: no local or systemic signs
Strain virulence variation
Virulence Factors Antigenic variation
Biofilms (in-vivo & in-vitro)
H2O2 – ciliotoxic and hemolytic
Adhesins – varied non-fimbrial types
Capsules
Urease - ureaplasmas , IgA protease
Superantigens – T-cell and antigen presenting cell activation Week 4, Lecture 20: PJL
M. gallisepticum
- tip organelle
- trachea
Mycoplasmas: Culture-based Dx Culture followed by specific Ab-based and/or PCR based identification Gold-Standard but ….. Time ……. Weeks for some
Overgrowth or pre-sample Abx affect culture outcome
Dx samples: resp. tract (TTA, lung tissue), joint fluid, milk, conjunctiva
Week 4, Lecture 20: PJL
Pure
Culture
Mycoplasma
“fried-egg”
microcolonies
Digitonin Sensitivity Assay
DSA
Broth
Amplification
Digitonin binds membrane cholesterol Mycoplasma’s cannot synthesize – cell death
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Mycoplasma Group: Rapid Dx
Week 4, Lecture 20: PJL
PCR Serology - cheaper
Multiplex PCR
Microarray coming
Pathogenic Mycoplasmas Bovine
M. bovis
M. mycoides subsp. mycoides (SCV)– Contagious Bovine Pleuropneumonia (CBPP) Reportable
Porcine
M. hyopneumoniae
M. hyorhinis – polyserositis & arthritis in 3-10 wk old pigs (sporadic)
M. hyosynovitis – polyarthritis in 12-24 wk pigs (sporadic)
Avian
M. gallisepticum
M. synoviae – Infectious synovitis (chickens & turkeys); air-sacculitis, anemia
M. meleagridis – air-sacculitis & osteodystrophy (turkeys)
M. iowae – reduced hatchability, embryo mortality (turkeys)
Laboratory Animal Infections
M. pulmonis – mouse/rat pneumonia
M. neurolyticum – conjuctivitis & “Rolling Disease” in mice (neurotoxin)
Miscellaneous & Haemoplasmas
Global
Most relevant but: - sub-Saharan Africa, Asia
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Evolution of Mycoplasma bovis
ACVIM Consensus Statement: M. bovis Infections in Cattle. J Vet Intern Med 2011: 25-772
1961 USA
1964 Israel
1970 Australia
1974 France, UK
1989 Brazil
2005 S. Africa
2008 China
Mb-free N.Z & Norway
Pathogenesis
Dairy Beef
Otitis
Media?
Mastitis Herd
Waste
Milk
Calves/Heifers
Colonization
Mastitis
Pneumonia
BRDC Pneumonia
Feedlot
2%-to-100%
Proximity &
repeated contact
30-60%
UK
30-40%
Italy
60-80%
CPPS – tenosynovitis/arthritis
Dairy: 7-20%
Bacteremia
Dissemination
3-4 weeks
after arrival
Otitis, arthritis
Arthritis
Nicholas, R. (2011) Bovine mycoplasmosis: silent and deadly. Vet. Record 168:459.
Mycoplasma bovis ~ $150 million/yr (US) – dairy & beef
Caseonecrotic bronchopneumonia
Cranioventral lobes
Subclinical–to-clinical insidious
Acute: multifactorial (BVDV, Mh/Pm/Hs or A. pyogenes
Chronic Pneumonia & Polyarthritis Syndrome
Dx – serology, PCR (TTA, conjunctiva), culture
Intervention: Management – Mb-free stockers, stress (shipping, cold)
Vaccine (Pulmo-GuardJ MpB)
Not in Canada
Metaphylaxis - Draxxin
Quarantine
Label use Abx: Tulathromycin (Draxxin)
Gamithromycin (Zactran)
Week 4, Lecture 20: PJL
Nicholas, R. (2011) Vet. Record, 168:459.
Otitis media
Eustachian tube
Insidious
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Mycoplasma bovis - Mastitis
Variable presentations: Hx of Abx failure Severe mastitis outbreaks “contagious agalactia”
Endemic subclinical (+/- changes in SCC)
Mastitis Signs: Hx of Abx failure Multiple quarters, not painful, mild systemic signs
Milk changes
Agalactia can resolve (often permanent)
Transmission Milk, resp. secretions, frozen semen
Infusion cannula misuse, damp sponges
Calves - pneumonia, arthritis, otitis media
Week 4, Lecture 20: PJL
Mycoplasma bovis - Mastitis Dx - Abx unrewarding, agalactia, no fever Milk culture (Hayflick’s) – PCR rapid, available, technical challenges
Intervention: Herd-size is risk factor
Eliminating from animal &/or herd challenging Clinical signs can resolve but : chronic shedders
Dairy Biosecurity – Closed-herd concept Bulk tank hx of farm of origin pathogen free stock-sources Quarantine and check
ACVIM- Treatment … not recommended. Confirm i.d., quarantine, cull(?)
No vaccines in Canada
Management:
Bulk tank monitoring (culture, ELISA, PCR)
Week 4, Lecture 20: PJL
VIDO - GAPDH vaccine research - Glycolytic pathway - Also adhesin
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M. hyopneumoniae – “Enzootic Pneumonia” of Swine
Growing/finishing pigs (25-100 kg) Chronic catarrhal/suppurative bronchopneumonia High morbidity (direct & aerosol) Low mortality
Risk Factors Stress: stocking density, ammonia levels Co-infections – PRRSV, Pm, H. parasuis, APP, Bb
Signs – Subclinical-to-Clinical
Chronic nonproductive cough “cough-score” reduced ADG and FCE anorexia, pyrexia, dyspnea (co-pathogens)
Post mortem: cranial lung lobes Histo - bronchiolar lymphoid infiltration/hyperplasia
Global
M. hyopneumoniae: Dx & Intervention
Antemortem - Herd ELISA, PCR (nasal swab)
Post mortem Culture – (Friis), most definitive but 4-8 weeks
Faster - Immunohistochemistry on lung tissue, PCR
Difficult to eliminate Parenteral - Tulathromycin (Draxxin®)- label-use
Feed – Prescription mix - Lincomycin
Management Strategies: Biosecurity
Herd surveillance program, restock with SPF
Stocking density, ammonia levels,
Vaccines (sows/piglets): RespiSure-One® Co-pathogens vaccine status as well
CFIA (FYI) - Compendium of Medicating Ingredient Brochures - Summary of Feed Drug Clearances
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Severe fibrinous pericarditis in a pig also affected with enzootic pneumonia.
et al. Veterinary Record 2008;162:537-540
Copyright © British Veterinary Association. All rights reserved.
M. gallisepticum
Chronic Respiratory Disease (CRD) in chickens
Infectious Sinusitis (IS) in turkeys
Habitat Colonization of resp./repro. mucosa
Lateral and vertical (Eggs/semen) transmission
Signs (good hygiene equals milder signs) Chickens - nasal discharge, tracheal
rales, coughing sneezing
Turkeys - swelling of infraorbital sinuses, mild conjunctivitis
’d ADG/FCE and egg production
Mortality low but can approach 30%
If co-infections (viruses, or E. coli )
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M. gallisepticum : Dx and Txt
Culture – respiratory tract (Frey’s Media)
Rapid tests – Serology (flock surveillance) Serum Plate Agglutination (SPA) test (Intervet) cheap
mix commercial Antigen (MG, MS, MM) with 0.2 mL serum agglutination = positive
PCR- readily available (PDS) Swabs or broth culture i.d.
Intervention- goal is prevention
MG-free breeder flocks – Egg dipping/heating Biosecurity, (all-in, all-out) Live vaccine available – MycoVAC-L (intervet) ocular instillation Abx in Feed: Tetracycline or Erythromycin
Misc. Non-haemotrophic Mycoplasmas (FYI - except one)
Bovine: many species (mastitis, conjunctivitis, resp./repro. tract infections)
M. bovoculi - keratoconjunctivitis M. dispar – calf pneumonia Ureaplasma diversum – role in vulvitis, infertility
Caprine & Ovine: many species (first two are Notifable)
M. capricolum subsp. capripneumoniae – Contagious Caprine Pleuropneumonia M. agalactiae – contagious agalactia M. capricolum subsp. capricolum – septicemia, mastitis, arthritis & pneumonia M. mycoides subsp. capri - septicemia, pleuropneumonia, arthritis & mastitis M. ovipneumoniae – small ruminant pneumonia
Canine
M. cynos – part of kennel cough
Feline
M. felis – conjunctivitis, foals (pleuritis) & humans (immuncomp) M. gateae - arthritis
Z
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Haemotrophic Mycoplasmas
Obligate RBC parasites (prev. Order Rickettsiales ; Genera Haemobartonella & Eperythrozoon)
Insect vectors (mosquito, tick, flea), direct transmission, transfusion
Cannot culture on artificial media
Subclinical to clinical hemolytic anemias, ill-thrift, infertility
~ 9 species described to date
Haemobartonella felis → M. haemofelis (Feline Infectious Anemia)
Haemobartonella canis → M. haemocanis (canine haemobartonellosis)
Eperythrozoon suis → M. suis (porcine icteroanemia)
Eperythrozoon ovis → M. ovis (Ovine/Caprine eperythrozoonosis)
Eperythrozoon wenyonii → M. wenyonii (Bovine eperythrozoonosis)
Several others that remain poorly characterized
Haemoplasmas
Feline Infectious Anemia
Mycoplasma haemofelis
Prevalence (0-50%) significance ?
Signs: pale m.m., lethargy, anorexia, depression, dehydration, pyrexia – can relapse/recur
Infection route – fleas, fights blood transfusion donors
Diagnosis: anemia Blood smear
PCR-based (commercial & routine Dx labs)
Doxycycline, Enrofloxacin Blood smear: Wright-Giemsa
Global