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.
The list of signs and symptoms mentioned in various sources for Shigella flexneri includes the 10 symptoms listed below: 1  Diarrhea. 2  Blood in stool. 3  Mucus in stool. 4  Pus in stool. 5  Fever. 6  Nausea. 7  Vomiting. 8  Stomach cramps. 9  Flatulence. 10  Straining during bowel movements. 11  more information...Â».