Mimivirus, illustration. Acanthamoeba polyphaga mimivirus (APMV), commonly known as mimivirus, consists of outer hairs, or fibrils, and a protein coat (capsid) enclosing a deoxyribonucleic acid (DNA) genome. Mimivirus is a genus of giant viruses, and has one of the largest capsid diameters known to date. It was initially mistaken as a bacterium due to the many fibres on its surface, which gives rise to the name, mimivirus, short for 'mimicking microbe'. APMV's classification as a pathogen is tentative, but it is now thought that it may cause viral pneumonia.