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 well-known cause of traveler's diarrhea and illness throughout the world. Shigella are extremely infectious bacteria, and ingestion of just 10 organisms is enough to cause severe diarrhea and dehydration.higellosis (shigÂ´ÉlÅÂ´sis) , n an infection of the gastrointestinal tract caused by. Shigella bacteria, usually contracted by the ingestion of tainted food or drink. Symptoms include fever, abdominal pain, and diarrhea.