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
After splenectomy, most common infection is 
Select and explain. 
A. Pneumococcus, B. Escherichia coli, C. Klebsiella, D. Streptococcus
A: Pneumococcus
Answer: A: Pneumococcus 
Explanation: Streptococcus pneumoniae cause infection when host resistance is lowered by contributory factors such as respiratory viral infection, pulmonary congestion, stress, malnutrition, immunodeficiency and alcoholism. Splenectomy and sickle cell disease are impoant predisposing conditions. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 227