This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Misc., Subject name: Microbiology
Organism showing "Medusa head" appearance and "Bamboo stick" appearance in blood culture medium. What is the likely organism? 
Select and explain. 
A. Bacillus anthracis, B. Corynebacterium diphtheria, C. Clostridium perfringens, D. Vibrio cholerae
A: Bacillus anthracis
Answer: A: Bacillus anthracis 
Explanation: (A) Bacillus anthracis# APPEARANCES OF THE COLONIES:# Bacteria Appearance> Staphylococci - Oil paint appearance (nutrient agar)> Pneumococci - Draughtmann/ carom coin appearance (blood agar)> Corynebacterium - Chinese letter or cuneiform arrangement> Bacillus anthracis Bamboo stick appearance Medusa head appearance (agar plates ) Inverted fir tree appearance (gelatin stab culture)> Cl. perfringens Stormy fermentation (litmus milk) Target haemolysis (rabbit, sheep, human blood agar)> Cl. tetani - Drum stick appearance> Vibrio cholarae - Fish in stream appearance> Yersinia pestis Safety pin appearance Stalactite growth> H. influenzae - Satellitism> H. ducreyi - School of fish Rail road track appearance> Bordetella pertussis Thumb print appearance Bisected pearls / mercury drops (Bordet-Gengou medium) Aluminium paint appearance> M. leprae - Cigar bundle appearance> Mycoplasma - Fried egg appearance