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BRUCELLA Sharq Elneil College School of Medical Laboratory Sciences Department of Microbiology Medical Bacteriology course Mr.Mahadi Hassan Mahmoud Bsc, Msc, MIBMS Microbiology

Brucella mahadi ppt

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Page 1: Brucella mahadi ppt

BRUCELLA

Sharq Elneil College

School of Medical Laboratory Sciences Department of Microbiology

Medical Bacteriology course

Mr.Mahadi Hassan Mahmoud Bsc, Msc, MIBMS Microbiology

Page 2: Brucella mahadi ppt

Historical Background

1897 A.E. Wright ; pathologist in British

army - developed agglutination test.

What is the source?

“Mediterranean Fever Commission” 1904

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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.

Historical Background

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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

Historical Background

Page 5: Brucella mahadi ppt

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

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Important species

B. melitensis >> goats & sheep

B. abortus >> cattle

B. suis >> pigs

Important: All 3 species can infect man and domestic animals

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Brucella species gram-negative bacilli

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Brucella abortus

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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.

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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.

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LABORATORY DIAGNOSIS

1. 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

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Brucella melitensis colonies

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2. Serological Tests

Standard agglutination test

Mercaptoethanol test

Complement fixation test

Coobs’ test

3. Brucellin Skin Test

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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

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Biochemical tests

Gram stain: Gram negative cocco bacilli

Biochemicals:

Catalase

Oxidase

Dye inhibition test

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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

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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

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Prognosis

Preantibiotic era

Mortality 2% mainly endocarditis

Morbidity

High with B. melitensis

Nerve deafness

Spinal cord damage

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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.

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THANK YOU FOR ATTENTION