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 is a group of bacteria that cause shigellosis, a type of bacterial infection that affects the lining of the intestines. The most common sources of this bacteria exist in areas that have poor sanitation and crowded living conditions. It is most common among travelers who are visiting developing countries.