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.
Shigella are a group of germs (bacteria) that can cause gastroenteritis with dysentery. Gastroenteritis is an infection of the bowels (intestines). Diarrhoea is one of the symptoms of gastroenteritis.If the diarrhoea contains blood and mucus, this is known as dysentery.higella are a group of germs (bacteria) that can cause gastroenteritis with dysentery. Gastroenteritis is an infection of the bowels (intestines). Diarrhoea is one of the symptoms of gastroenteritis.