Mycoplasma Group: Overview

Transcription

1 Mycoplasmas, Ureaplasmas & Haemoplasmas Illustration by David S. Goodsell, the Scripps Research Institute Mycoplasma Group: Overview Facultative anaerobes, stain poorly Tiny cell ( um) Trilaminar plasma membrane Lipoprotein & phospholipid Transmission Electron Microscope 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 Scanning Electron Microscope 1

2 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) H 2 O 2 ciliotoxic and hemolytic Adhesins varied non-fimbrial types Capsules M. gallisepticum - tip organelle - trachea Urease - ureaplasmas, IgA protease Superantigens T-cell and antigen presenting cell activation 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 Pure Culture Mycoplasma fried-egg microcolonies Broth Amplification Digitonin binds membrane cholesterol Mycoplasma s cannot synthesize cell death Digitonin Sensitivity Assay DSA 2

3 Mycoplasma Group: Rapid Dx PCR Serology - cheaper Multiplex PCR Microarray coming Bovine M. bovis Pathogenic Mycoplasmas M. mycoides subsp. mycoides (SCV) Contagious Bovine Pleuropneumonia (CBPP) Reportable Porcine M. hyopneumoniae Most relevant but: - sub-saharan Africa, Asia M. hyorhinis polyserositis & arthritis in 3-10 wk old pigs (sporadic) M. hyosynovitis polyarthritis in wk pigs (sporadic) Global 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 3

4 1961 USA Evolution of Mycoplasma bovis Dairy: 7-20% Pathogenesis Proximity & repeated contact 1964 Israel 30-60% Dairy Nicholas, R. (2011) Bovine mycoplasmosis: silent and deadly. Vet. Record 168: Australia Herd Mastitis 1974 France, UK 1989 Brazil UK 30-40% Italy 60-80% Calves/Heifers Waste Milk Bacteremia Dissemination Beef Feedlot 2%-to-100% Otitis Media? 2005 S. Africa 2008 China Mb-free N.Z & Norway Pneumonia Colonization Mastitis Otitis, arthritis Arthritis Pneumonia 3-4 weeks after arrival BRDC CPPS tenosynovitis/arthritis ACVIM Consensus Statement: M. bovis Infections in Cattle. J Vet Intern Med 2011: 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 Otitis media Eustachian tube 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) Insidious Nicholas, R. (2011) Vet. Record, 168:459. 4

5 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 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 VIDO - GAPDH vaccine research - Glycolytic pathway - Also adhesin Management: Bulk tank monitoring (culture, ELISA, PCR) 5

6 M. hyopneumoniae Enzootic Pneumonia of Swine Growing/finishing pigs ( kg) Chronic catarrhal/suppurative bronchopneumonia High morbidity (direct & aerosol) Low mortality Global 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 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 CFIA (FYI) - Compendium of Medicating Ingredient Brochures - Summary of Feed Drug Clearances Management Strategies: Biosecurity Herd surveillance program, restock with SPF Stocking density, ammonia levels, Vaccines (sows/piglets): RespiSure-One Co-pathogens vaccine status as well 6

7 Severe fibrinous pericarditis in a pig also affected with enzootic pneumonia. et al. Veterinary Record 2008;162: 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 ) 7

8 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 8

9 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 Global 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 9