What are the characteristics of Yersinia pestis?
Yersinia pestis — Key Characteristics
- Gram-negative bacilli, possible bipolar staining and a “safety pin” appearance.
- Nonhemolytic.
- Growth is faster at 25 to 28 degrees C than at 35 to 37 degrees C.
- At 48 to 72 hours the colonies on sheep blood agar have a “fried egg” appearance.
- Catalase positive.
Is Yersinia Gram positive or negative?
Yersinia pestis is a nonmotile, slow-growing, facultative organism classified in the family Enterobacteriaceae. It appears as plump, gram-negative coccobacilli that are seen mostly as single cells or pairs, which may exhibit bipolar staining from a direct specimen if stained with Wright’s or Giemsa stains.
Is Yersinia Ruckeri motile?
Motility (Section 2, 3.8. C “Motility”) Yersinia ruckeri is motile. Non-motile isolates may be reported as negative for Y.
Why is Yersinia pestis unique?
Y. pestis is unique in being carried by fleas and is transmitted when the flea bites a new animal host. Y. pestis blocks the digestive tracts of fleas by forming biofilms.
What environment does Yersinia pestis live in?
Y. pestis has two main habitats—in the stomach of proventriculus of various flea species at ambient temperature or in the blood or tissues of a rodent host at body temperature (Perry 19997 in Prentice and Rahalison 2007). Y. pestis has been recorded to naturally infect over 203 rodent species and 14 lagomorph species.
How does Yersinia pestis look like?
Curved, straight or bean-shaped: bacilli come in many variants and are widely spread. Yersinia pestis is a facultative anaerobic, Gram-negative, rod-shaped bacterium of the Enterobacteriaceae family. It is the pathogen of Black Death (zoonosis).
Is Yersinia a coliform?
The coliform group, as defined above, includes species of the genera Citrobacter, Enterobacter, Escherichia, Hafnia, Klebsiella, Serratia and Yersinia.
What causes red mouth disease?
Enteric redmouth disease (ERM) is a serious septicemic bacterial disease of salmonid fish species. It is caused by Yersinia ruckeri, a Gram-negative rod-shaped enterobacterium. It has a wide host range, broad geographical distribution, and causes significant economic losses in the fish aquaculture industry.
How does Yersinia pestis infect cells?
During the initial encounter with macrophages during infection, Y. pestis enters the macrophage through binding of its surface proteins, such as Pla, Ail, YadBC, and OmpX, to undetermined receptors present on the macrophage surface. However, following release from the macrophage through another undefined mechanism, Y.
How does Yersinia pestis infect the body?
Bubonic plague is the most common form of plague. This occurs when an infected flea bites a person or when materials contaminated with Y. pestis enter through a break in a person’s skin. Patients develop swollen, tender lymph glands (called buboes) and fever, headache, chills, and weakness.