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.
This can happen when you: Touch your mouth. If you don't wash your hands well after changing the diaper of a child who has shigella infection, you may become infected yourself. Direct person-to-person contact is the most common way the disease is spread. Eat contaminated food. Infected people who handle food can transmit the bacteria to people who eat the food.