E.Coli is a gram negative bacilli. Mostly found in the animal and human intestine as a commensals. Most strains are motile and some are encapsulated. They ferment lactose so in macconkey agar it produced pink colonies .E.Coli causes Hospital acquired and community acquired infection . Commonest cause for UTI is E.coli and it also causes neonatal meningitis , septicemia, peritonitis and Diarrhea
There four main diarrhea producing strains of E.Coli
1.Enteropathogenic E.Coli EPEC
2.Enterotoxigenic E.Coli ETEC
3.Enteroinvasive E.Coli EIEC
4.Enterohemorrhagic E.Coli EHEC
usually diseases caused by an endogenous pathogen from the host's normal flora and less commonly caused by exogenous pathogen from human or animal intestine in endogenous infection organism reach the site of infection from gut .exogenous infection organism contaminated with environment and then invade the human . diarrheagenic organism excreted from feces and contaminate with food and water and then through oral root organism reach to the gut
For diagnosis sample taken from site of infection eg - mid urine sample in UTI , stools in diarrhea , blood in septicemia CSF in meningitis and sample used for gram stain and culture and ABST
For Treatment following Antibiotic can be used
- Amoxicillin
- Cephalosporin
- Quinolone
- Aminoglycoside