exists and is an alternate of . The sperm that reach the egg swim into it and attempt to penetrate the zona pelluca, which is the semi permeable outer membrane of the egg. Some sperm have a shape which makes this relatively easy, and others which are poorly formed are likely to have more difficulty.
1 Shigellosis is an infectious disease caused by a group of bacteria called Shigella. 2  Symptoms of Shigella infection include diarrhea (often bloody), fever, and stomach cramps starting a day or two after exposure to the bacteria. 3  Shigellosis usually resolves in 5 to 7 days.
1 Other causes of dysentery include the parasite amoeba and the bacteria E. coli, Yersinia, and others. 2  The shigella bacillus is typically spread via contact with the fecal matter of an infected person. 3  Failure to wash the hands thoroughly after a bowel movement may help to transmit shigellosis.acillary dysentery, also known as shigellosis, is a potentially dangerous and extremely contagious bacterial infection of the colon. Symptoms develop after an incubation period of one to four days and generally subside within 10 days.