Control of mycoplasma infection of poultry by antibiotics

Transcription

1 Control of mycoplasma diseases of poultry, swine and cattle Control of mycoplasma infection of poultry by antibiotics László Stipkovits and Susan Szathmáry RT-Europe Research Center, Mosonmagyaróvár, Hungary

2 Introduction Main characteristics of mycoplasma infections Control of mycoplasma infections by antibiotics 10/18/2012 2

3 Pathogenic Mycoplasma species of chicken and turkey M.gallisepticum M.synoviae M.meleagridis M. iowae Ureaplasma CRD, arthritis, nervous symptoms, embryo mortality, egg drop CRD, arthritis, nervous symptoms, embryo mortality, egg drop CRD, embryo mortality, lameness) Embryo mortality, leg problems Egg infertility, 10/18/2012 3

4 Main phenotypic properties of mycoplasmas Minimal genetic information (they are fastidious, difficult to culture), Lack of cell wall (closed association with host cells, selective antibiotic sensitivity, inhibition of phagocytosis), Invasiveness (chronic infection, difficult treatment, various antibiotic sensitivity), Changing of the antigen structure (low immunity, diagnostic problems) 10/18/2012 4

5 Attachment of Mycoplasmas to epithelial cells 10/18/2012 5

6 Tracheal mucosa of a chicken challenged by M. gallisepticum (100x) 10/18/2012 6

7 Chickens infected with M. gallisepticum 10/18/2012 7

8 Peritonitis of a chicken challenged by M. gallisepticum 10/18/2012 8

9 Airsacculitis due to M.synoviae 10/18/2012 9

10 Arthritis of a turkey challenged by M. synoviae 10/18/

11 RBCs from an experimentally M. gallisepticum-infected chicken after DIF staining Superimposed picture after FITC- and Alexa Fluor 633-labeling showing M. gallisepticum attached to the RBC s surface (yellow label) and inside the chicken RBC (red label) after experimental in vivo infection. The erythrocytes were visualized by differential interference microscopy. 10/18/

12 Inflammation of follicles in hen due to M. gallisepticum 10/18/

13 10/18/

14 Healthy vs infected semen 10/18/

15 Phagocytosis 10/18/

16 Airsacculitis due to M.gallispeticum & E. coli 10/18/

17 Prevalence of E. coli seropositivity and airsacculitis in M. gallisepticum infected flocks M.gallisepticum seropositivity (%) E. coli Airsacculitis E. coli seropositivity 0 5,0 7, ,7 5, ,2 7, ,9 10, ,2 21,8 10/18/

18 Egg transmission of E. coli in infected flock egg prod. % E.c. egg trans days 10/18/

19 70 Effect of E. coli infection on egg production and egg transmission in M. gallisepticum infected flock 60 % Infected Control E.coli inf days 10/18/

20 Effect of M. gallisepticum infection on other bacterial infections Parameters M.gallisepticum positive flock M.gallisepticum negative flock Pasteurella multocida septicemia Bordetella bronchiseptica septicemia Staphylococcus aureus septicemia 35.0% 3.4% 23.3% 1.8% 24.6% 1.6% 10/18/

21 Effect of M.gallisepticum infection on serological response and pathology induced by vaccines Parameters M.gallisepticum positive flock M. gallisepticum negative flock Seropositivity induced New castle vaccine Airsacculitis caused by New castle vaccine Seropositivity induced by Inf. bronchitis vaccine Airsacculitis induced by inf. bronchitis vaccine 67.9% 94.8% 15.2% 0.9% 76.8% 96.8% 13.9% 0.6% 10/18/

22 Effect of LPAI H3N8 virus on M. gallisepticum infection Parameters M.gallisepticum + LPAI H3N8 M. gallisepticum Difficult breathing Body weight (g) 1,432 1,677 Scores of airsacculitis Thickness of tracheal mucosa (nm) Tracheitis and bronchitis Isolation of mycoplasmas from inner organs /18/

23 Pathological lesions M. gallisepticum M. gallisepticum and LPAI H3N8 10/18/

24 Section of trachea of chickens Negative control LPAI H3N8 10/18/

25 Section of trachea of chickens M. gallisepticum M. gallisepticum + LPAI H3N8 10/18/

26 Losses caused by of Mycoplasma infection Direct losses: embryo mortality 5-20% chicken mortality 5-10% retarded growth 10-25% condemnation at slaughter 5-10% decrease of egg production 8-20% 10/18/

27 Economic impact of mycoplasma infection Increased mortality, FCR Decreased egg production, hatchability, downgrading of carcasses, Increased sensitivity to E. coli, H. paragallinarum, NC, IB and LT viruses even to vaccine viruses, stress factors of environment, Weak serological response to vaccines. 10/18/

28 Antimicrobials 10/18/

29 Control of M. gallisepticum infection by antibiotics to reduce economic losses Advantage Reduction of mycoplasma population, Prevent penetration of mycoplasmas in eggs, Possible eradication. Disadvantage Variability of antibiotic sensitivity of strains, Frequent usage, Development of resistance. 10/18/

30 Classification of antibiotics based on the mode of action Inhibitors of cell wall synthesis Beta-lactams (e. g. penicillin type of drugs), Beta-lactam + beta-lactamase inhibitor (such as Amoxicillin + Clavulanic Acid), no effect on mycoplasmas Inhibitors of membrane function Polymixin B, colistin moderate effect Anti-metabolites Sulfonamides or trimethoprim moderate effect 10/18/

31 Classification of antibiotics based on the mode of action Inhibitor of nucleic acid synthesis Fluoroquinolones good effect Inhibitors of protein synthesis Macrolides (erythromycin, tylosine, tilmycosin, lincomycin, kitasamycin, spiramycin, tylvalosin), aminoglycosides (gentamicin, tobramycin), Target:30S ribosomal sub-unit Tetracyclines (OTC, CTC, doxycycline) Target:30s ribosomal subunit Pleuromutilins (Tiamulin, valnemulin) Target: 50S ribosomal subunit good effect 10/18/

32 Principles of antibiotic treatment of M. gallisepticum infection Testing of MIC of isolates (mycoplasmas and bacteria) to antibiotics, Selection of dose taking into consideration of pharmacodynamic and pharmacokinetic properties of antibiotics (concentration in target tissues), Determination of treatment regime (appearance of disease, management), Application of combinations having synergistic effect. 10/18/

33 Eradication of mycoplasma infection Parent stock Mycoplasma infected Clinically diseased flock-50% egg transmission, In treated flock- 1% egg transmission. Eggs for hatching should be collected when the sufficient antibiotic level is in the eggs (in case of Tiamulin 0.2 microgram/ml) Treatment of eggs by injection or dipping or temperature treatment-egg transmission 0.03 % In case of hatching eggs offspring chicks will have 0.01 % infection. If these chicks are placed in one air space, the flock will be infected

34 Eradication of mycoplasma infection If the flock is divided in 2 groups, one group will be infected (50%), If the flock is divided into 4 groups, one group will be infected, 3 groups will be negative (75%), It is necessary to keep the groups separately and regularly monitor.

35 Perspectives of mycoplasma infections of poultry Individual testing procedure of mycoplasma infection is not perfect Genetic work (and production) needs to mix different groups of birds and mycoplasma infection should be always excluded, Continuous antigen variation of mycoplasmas should be followed by improvement of serological diagnostic tests, Intensive study of function immune system and development of test methods are needed 10/18/

36 Thank you for your attention

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