This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Enterobecteriaceae, Subject name: Microbiology
[{'content': 'All are capsulated EXCEPT: \nSelect and explain. \nA. Klebsiella pneumonia, B. Hemophilus influenza, C. Bacillus anthracis, D. Escherichia coli', 'role': 'user'}, {'content': 'Answer: D \nExplanation: ANSWER: (D) Escherichia coliREF: Anantnarayan 8th ed various chapters, Jawetz 24th edition Chapter 16(Note: Although K strain of E. coli is capsulated it is the best possible answer amongst the optionsprovided)E cob are classifiedby more than 150 different heat-stable somatic O (lipopolysaccharide) antigens, more than 100 heat-labile K (capsular) antigens, and more than 50 H (flagellar) antigens.K antigens are external to O antigens on some but not all Enterobacteriaceae. Some are polysaccharides, including the K antigens of E. coli; others are proteins.Cell envelope (cytoplasmic membrane,peptidoglycan, outer membrane)A common mnemonic used to remember some encapsulated pathogens is:"Even Some Super Killers Have Pretty Nice big Cars"Escherichia coli (K strain), Streptococcus pneumoniae, Salmonella, Klebsiella pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, Neisseria meningitidis, Bacillus anthracis and Cryptococcus neoformans.', 'role': 'assistant'}]