Slow Lactose Fermenters - Edwardsiella spp.

Gram negative, facultatively anaerobic, rod shaped bacteria of the family Enterobacteriaceae

Occasionally opportunistic pathogen for humans

• Serratia

• Citrobacter

• Edwardsiella

• Arizona

Only clinically significant in humans of Edwardsiella spp.

• E. tarda

• E. hoshinae

• E. ictaluri

• True

• Alam mo na gagawin

• Kapag hindi pa, jusko naman

Resembles Citrobacter and Salmonella by its production of H2S on TSI agar

Grows well on differential media as it produce small, smooth, glistening, semi-translucent colonies

• E. tarda

• E. hoshinae

• E. ictaluri

Associated infections of E. tarda

• Bacterial gastroenteritis

• Wound infections: cellulitis or gas gangrene associated with

  trauma to mucosal surfaces

• Systemic disease: septicemia, meningitis, cholecystitis and

  osteomyelitis

Risk factors of E. tarda

• Exposure to aquatic environments or exotic animals

  (e.g., reptiles or amphibians)

• Pre-existing liver disease

• Conditions leading to iron overload

• Dietary habits (e.g., raw fish ingestion)

• Initially recovered from birds, reptiles, and water

• Recovered from human feces but is not known to cause diarrhea

• Motile

• E. tarda

• E. hoshinae

• E. ictaluri

• Recovered only from fish and presently has no clinical significance

• Nonmotile species that does not produce indole

• Causes enteric septicemia in catfish

• Low optimal growth temperature

• E. tarda

• E. hoshinae

• E. ictaluri

Edwardsiella spp. is susceptible in vitro to:

• Beta-lactams and Cephalosporins

• Aminoglycosides

• Fluoroquinolones

• Chloramphenicol

• All of the choices

Edwardsiella spp. is resistant to:

• Polymyxin B

• Colistin

• Penicillin (Occasionally)