BACILLUS SP Basmah almaarik Lab 9 v Spore

BACILLUS SP Basmah almaarik #Lab 9

v Spore forming facultative anaerobic bacteria. v Grow every where cause it produce spores. v Grow in wide rage 12 -45 ºC v Spore formation is best seen in 25 – 30 ºC v Grow on NA and BAP

v Bacillus anthracis: Causes anthrax; Mainly disease of sheep, cattle but human can be infected. Highly infectious and pathogenic. Need special precaution to work with. v Bacillus cereus: Produce toxin that cause food-poisoning. Toxin is produced when the bacilli sporulate, usually in rice that have been stored in warm temperatures. v Bacillus subtilis: Is not considered a human pathogen; it may contaminate food but rarely causes food poisoning

� B. anthracis � Aerobic � B. � Large � Non � Markedly irregular colonies with wavy edges. (Ground glass appearance. ) haemolytic or slightly haemolytic cereus � Aerobic irregular colonies with wavy edges. (Ground glass appearance. ) haemolytic

B. anthracis B. cereus

� Non motile. � Sensitive to Penicillin. � Capsulated B. anthracis � Motile � Resistant to penicillin. � Non-capsulated. B. cereus

ØAll Bacillus are Gram Positive Bacilli. ØHave spores; §Inside or outside the cells §Central or terminal � B. anthracis � Non-motile. � Capsulated. � B. cereus � Motile. � Non-capsualated.

1) 2) 3) Malachite Green (differential stain) Nigrosin Stain (negative stain) Ziehl-Neelsen Stianing

1. 2. 3. 4. 5. 6. 7. Add drop of saline on a clean slide. Touch organism with loop and emulsify in saline. Spread, then fixe slide in hot plate. Flood slide with warm malachite green for 5 m Wash with water. Counter stain with safranin 3 -2 m Wash then dray.

Spores can be inside or outside of cells. Central or terminal

1. 2. 3. 4. 5. 6. Add drop of saline on clean slide. Touch organism by loop; emulsify in saline but do not spread. Add 1 drop of nigrosin and 1 drop of safranin. Mix all together by wooden stick. Then spread by the edge of another slide. Air dray and examin

1 drop negrosin � Dark background � Bacilli � Spores Drop of saline with loopful of organism colorless red 1 drop carbol fuschin Mix al together then spread like blood film and examine.

� Back ground blue. � Bacilli blue � Spores red.