Salmonella species can cause diseases ranging from gastroenteritis to typhoid fever, and can be transmitted through the ingestion of contaminated food or water. Upon entering the host cell there is an increase in the levels of intracellular free calcium as well as a rearrangement of the cell cytoplasm. Salmonella also ruffles the membrane, which appears to be an important part in the entry process. The most common Salmonella infections (generally by Salmonella enterica serovar Enteritidis) generally cause diarrhea, fever, or abdominal cramps. Salmonellosis can usually resolve itself without treatment 5-7 days after infection unless the host becomes severely dehydrated or if the infection spreads. While it generally can be treated with ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin, some of the bacteria have become resistant to certain antibiotics as a result of using antibiotics to promote the growth of feed animals. Although most people with this type of Salmonella infections usually recover completely, a small amount of people develop Reiter's syndrome which causes pains in their joints, irritation of their eyes, and painful urination. This syndrome can last for months, years, or can even lead to chronic arthritis (CDC).