This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
Impetigo contagiosa is caused by 
Select and explain. 
A. Group A beta hemolytic streptococci, B. Staphylococcus, C. Hemophilus influenzae, D. Pseudomonas
A: Group A beta hemolytic streptococci
Answer: A: Group A beta hemolytic streptococci 
Explanation: Impetigo is caused by Streptococcus pyogenes belonging to a limited number of serotypes, usually high numbered M types, instead of the lower numbered M types which cause throat infection. Impetigo and streptococcal infection of scabies is the main cause of acute glomerulonephritis in children in tropics. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 215