New Discoveries Toxins from Gram Negative Bacteria Escherichia coli (E. coli)

Escherichia coli is a member of the family Enterobacteriaceae and the enteric group Escherichia- Shigella. Although the genus Escherichia includes six species, E. coli is by far the most command the bacterial species most frequently isolated in the clinical microbiology laboratory. It is normally found in the gastrointestinal tracts of humans and animals. E. coli can be spread from person to person by the fecal-oral route and by contaminated food, unchlorinated water, raw milk, and improperly cooked beef. The source of contamination is usually bovine manure. E. coli causes both extraintestinal and gastrointestinal infections, including urinary tract infections, septicemia, healthcare-related pneumonia, and wound infections. The most common extraintestinal E. coli infections are urinary tract infections (UTI) in young women of childbearing age. In addition, E. coli catheter-associated UTI is the most common healthcare-related Infection. UTI can subsequently result in bloodstream infections. E. coli has now surpassed Streptococcus agalactiae as the leading cause of early-onset meningitis in neonates due to the adoption of screening and prophylaxis for group B streptococci in pregnant females. The strains causing gastroenteritis or enteritis can be grouped according to clinical presentation: the most common is enterotoxigenic E. coli (ETEC), associated with chronic, persistent diarrhea and possibly a common cause of diarrhea in infants, young toddlers, and adults; enteropathogenic E. coli (EPEC), the cause of infantile diarrhea worldwide that results in fever, vomiting, and watery diarrhea; enteroinvasive E. coli (EIEC), the E. coli type (pathovar) that is closely related to Shigella and that causes symptoms ranging from a mild form of diarrhea to a dysentery-like disease.