Dr.Baha,Hamdi AL-Amiedi Ph. D.Microbiology

Transcription

1 BACILLUS ANTHRAX Dr.Baha,Hamdi AL-Amiedi Ph. D.Microbiology

2 BACILLUS ANTHRACIS

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4 BACILLUS ANTHRAX Dr.Baha,Hamdi AL-Amiedi Ph. D.Microbiology

5 Bacillus:General characters Anthrax is a zoonotic disease (could be transferred from animals to humans) caused by the spore-producing bacterium Bacillus anthracis. It is Gram positive,non-motile, rod shape, spore bearing, Aerobic bacilli occurring in chains. Two pathogenic species : Bacillus anthracis: causes Anthrax disease Bacillus cereus : causes (food poisoning ) gastroenteritis

6 Bacillus anthracis Causces anthrax, a disease especially prevalent in goats, sheep, and cattle It is a spore former, spores is very stable, resistant to dry, heat, Ultraviolent light play an important role in transmission to human & cause infection, they can survive in soil or skin of animals for years. It is unique in that it is only bacterium with protein(poly- capsule composed D-glutamic acid )

7 Clinical manifestation Bacillus anthracis causes three different forms of anthrax: 1-cutaneous anthrax 2-Pulmonary anthrax 3-gastrointestinal anthrax

8 Cutaneous anthrax the most common naturally occurring form of the disease and is characterized by local inflamatory necrotic lesion (eschar) at the site of inoculation transmitted through contact with spores in the infected animals or animal products (wool, hair, bone)

9 Cutaneous Anthrax

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11 PULMONARY ANTHRAX Also called( Woolsorters disease) : is a highly fatal form of disease characterized by rapid and massive edema in the cheast followed by cardiovascular shock and death transmitted occurs when spores inhaling from infected animals or animals products

12 PULMONARY ANTHRAX Inhalation of the dust or filaments of wool from infected animals, particularly in wool factories ( wool sorter s disease) Haemotogenous spread 50% meningitis

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14 Chest X-ray Chest X-rays is advised as an initial method of inhalation anthrax detection, but it is sometimes not useful for patients without symptoms. Find a widened mediastinum and pleural effusion. At day 1 At day 3

15 Gastroingtestinal anthrax Which result from ingestion of spores, is very rare but highly fatal transmitted when spores from infected animals or animals products these spores are ingested

16 INTESTINAL ANTHRAX Consumption of improperly cooked infected meat. Causes violent enteritis with bloody diarrhoea All clinical conditions lead to septicaemic anthrax if not treated early Highly fatal!!!

17 Pathogenesis/Virulence factors Bacillus anthracis contain several virulence factors: a- A capsule of D-glutamic acid is antiphagocytes and helps the microorganism to evade the immune system of the host

18 Pathogenesis/Virulence factors b- three exotoxins are product : 1-protactive antigen(pa): bind the anthrax toxin receptor (ATR) on the surface of host cells and facilitates the other ( translocation of the 2 exotoxins, edema factor (EF) and the lethal factor (LF) into the cell.

19 2-Edema factor ( EF): is an adenlyate cyclase that increase intracellular camp Stimuling an efflux of fluids and ions that results in edema 3-Lethal Factor (LF) is a mitogen activated protein kinase kinase (MAPKK) protease that Disrupts cell signaling causing cell death & tissue necrosis.

20 Mod of action of anthrax Toxin

21 Laboratory diagnosis 1-smear prepared from exudates, sputum show gram positive bacilli, non-sporing bacilli occur in chain 2-cultur: the material is inoculated on Nutrient Agar & Blood Agar nonhemolysin, with medosa head shape appearance,smear from cultur shows gram positive bacilli spore in the center of bacili with chain arrange

22 Gram stain Microscopy Gram stain for bacilli demonstration McFadyean s reaction for capsule demonstration. Spore staining for spore demonstration. McFadyaen s reaction Spore stain

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24 Culture Other non-selective media Nutrient agar colonies medusa head appearance on low power microscopy Blood agar usually non-haemolytic

25 Laboratory diagnosis 3-Macfadyen test: it is special stain for capsular of bacillus anthracis 4-Serological test(ascoli Test): it is precipitate & rapid diagnosis zone of precipitate at junction of tissue extract & antiserum within 5 minutes at room temperature means positive result of Ascoli Test. 5-Animal inoculation: injected subcutaneously in guinea big which dies within hours, smear from heart blood & spleen show gram positive bacilli

26 Ascoli Test

27 al-microbiology-ii/summary-of-bacterialpathogens/bacillus-anthracis olistname/page/ References