Brucella mahadi ppt

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Brucella mahadi ppt

  1. 1. Sharq Elneil CollegeSchool of Medical Laboratory Sciences Department of Microbiology Medical Bacteriology course BRUCELLA Mr.Mahadi Hassan Mahmoud Bsc, Msc, MIBMS Microbiology
  2. 2. Historical Background 1897 A.E. Wright ; pathologist in British army - developed agglutination test. What is the source? “Mediterranean Fever Commission” 1904
  3. 3. Historical Background 1905 Zammit; Maltese physician - Goats were the source of infection. 1897 E. Bang; Danish veterinarian -described intracelular pathogen causing abortion in cattle named “Bacillus abortus”. 1918 A. Evans; American microbiologist -made the connection between Bacillus abortus and micrococcus melitensis & named it Bacteriaceae.
  4. 4. Historical Background  1920 Meyer and Shaw suggested BRUCELLA 1914 Mohler isolated organism from liver & spleen of Pigs--B.suis. 1957 B. neotome, 1963 B. ovis, 1966 B. canis
  5. 5.  Aerobic, Gram-negative bacilli  Appear as cocci, coccobacilli and short bacilli Non-motile, non-capsulate Optimum temp. >> 37oC Facultative intracellular parasites Essentially pathogens of goats, Cattle, sheep and pigs Causative agents of Brucellosis (typical zoonosis) worldwide Also known as Malta, Mediterranean or undulant fever
  6. 6.  Important species  B. melitensis >> goats & sheep  B. abortus >> cattle  B. suis >> pigs Important: All 3 species can infect man and domestic animals
  7. 7. Brucella speciesgram-negative bacilli
  8. 8. Brucella abortus
  9. 9. Transmission Zoonosis affecting domestic animals. Concentrated in milk, urine, genital organs.ROUTES OF TRANSMISSION Oral : unpasteurised milk & products raw milk or meet. Respiratory: lab workers. Skin: accidental penetration or abrasion  - at risk farmers & veterinarians. Other routes: Conjunctival, Blood transfusion, Transplacental, ? person to person.
  10. 10. PATHOGENESIS Incubation period: 10-30 days Symptoms may be delayed for months Enter the body through:  Skin abrasions, mucous membranes of the alimentary or respiratory tracts and sometimes the conjunctivae>> reach the blood through regional lymphatics. Symptoms may vary without the fluctuating temperature to act as guide. Bacteria localize in various parts of the reticulo-endothelial system resulting in complications in any part of the body. Symptoms include: malaise, low-grade fever, lassitude, insomnia, irritability and swelling around the joints.
  11. 11. LABORATORY DIAGNOSIS1. Blood Culture Specimen  Blood (10 ml volumes) Inoculate  Blood culture tubes or bottles (glucose-serum broth)  Incubate in 10% CO2  Cultures should be retained for at least 6-8 weeks before being discarded as negative
  12. 12. Brucella melitensis colonies
  13. 13. 2. Serological Tests Standard agglutination test Mercaptoethanol test Complement fixation test Coobs’ test3. Brucellin Skin Test
  14. 14.  Laboratory  WBC (N) or . monocytosis  ESR of little help  Blood cultures  slow growth = 4 weeks  new automated system BATEC identifies he organism 4-8 days  more recent (BACT/ALERT) - 2.8 days PCR
  15. 15. Biochemical tests Gram stain: Gram negative cocco bacilli Biochemicals: Catalase Oxidase Dye inhibition test
  16. 16. Laboratory Diagnosis  Serology  Main laboratory method of diagnosis  Serum agglutination test - most widely used measures agglutination for IgG, IgM, IgA 2ME - break sulf-hydrile bonds in IgM polymer - no agglutination
  17. 17. which level is diagnostic ?? 1 : 160 - non endemic area 1 : 320 - endemic area SAT - false negative  Prozone  Blocking antibodies Other tests: coombs, ELISA, CFT, FTA
  18. 18. Prognosis Preantibiotic era  Mortality 2% mainly endocarditis Morbidity  High with B. melitensis  Nerve deafness  Spinal cord damage
  19. 19. Antimiocrobial S.T Combination of streptomycin and tetracycline or rifampicin and doxycycline Vaccination of young cattle (6-8 months) Pasteurization of milk or milk products Eradication by compulsory testing animals and slaughtering positive reactors.
  20. 20. THANK YOU FOR ATTENTION

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