Proteus vulgaris bacteria,scanning electron micrograph (SEM). This Gram-negative,rod-shaped bacterium is covered in flagella (thread-like projections),which are used for locomotion. These two cells are in the final stages of binary fission,a type of asexual reproduction. P. vulgaris forms a natural part of the intestinal flora in animals and humans,and is also found in water. In people whose immune systems are suppressed,for example those with AIDS or those taking immunosuppressant drugs,it can be pathogenic,infecting the urinary tract or causing pneumonia or septicaemia. Magnification: x22,500 when printed 10 centimetres tall |