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.
Shigellosis is a diarrheal disease caused by a group of bacteria called Shigella. Shigella causes about 500,000 cases of diarrhea in the United States annually 1. There are four different species of Shigella 1  : Shigella sonnei (the most common species in the United States).ymptoms of shigellosis typically start 1â2 days after exposure and include: 1  Diarrhea (sometimes bloody). 2  Fever. 3  Abdominal pain. 4  Tenesmus (a painful sensation of needing to pass stools even when bowels are empty).