Question

Describe the pathogenesis of the clinically relevant members of the family Enterobacteriaceae.

Answer 1

Enterobacteriaceae.

Enterobacteriaceae is a group of gram negative bacterias. These are rod shaped , non - spore forming, anaerobic bacterias.Some bacterias are pathogenic and some are non pathogenic.

These bacterias are the normal inhabitant of intestinal tract of humans and animals. This group includes number of pathogens such as klebsiella, enterobacter, citrobacter, salmonella, escherichia coli, shigella, proteus, serratia and other species. They ferment glucose, reduces nitrates to nitrite and are oxidase negative.

These bacterias cause nosocomial infections including those affecting lungs, urinary tract, intra abdominal cavity and intravascular devices.

This organism can be easily isolated from clinical specimen and biochemical test. This bacterial infections include bacteremia, lower respiratory tract infections, urinary tract infections, endocarditis, intra - abdominal infections, septic arthritis, osteomyelitis, CNS infections, ophthalmic infections etc.

Urinary tract infections are mostly caused by E. coli. These infections are obtained by catheter through urethra or Supra-pubic. Pneumonia spread by personnel and equipment. Abdominal infections are caused by flora of gastrointestinal tract. Like pneumonia meningitis are also nosocomial infection.

Like all other bacterias enterobacteriaceae can develop resistance to antibiotics including carbapenem. Carbapenem are refered as the last line of antibiotic treatment against resistant organisms.