What is the shape of Yersinia pestis?
What is the shape of Yersinia pestis?
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).
What is unique about Yersinia pestis?
The high pathogenicity of Y. pestis is to a significant extent due to the unique ability of the bacteria to overcome the defence mechanisms of both mammals and insects, thus ensuring their survival during the entire transmission cycle.
What did Yersinia pestis look like?
General characteristics. Y. pestis is a non-motile, coccobacillus, facultative anaerobic bacterium with bipolar staining (giving it a safety pin appearance) that produces an antiphagocytic slime layer. Similar to other Yersinia species, it tests negative for urease, lactose fermentation, and indole.
How do you differentiate Yersinia enterocolitica and Yersinia pestis?
Yersinia Species Species are differentiated by a variety of traits, such as production of urease (Y. pestis is negative), motility (Y. pestis is nonmotile at 25°C and 37°C), ornithine decarboxylase (Y. enterocolitica is positive), and rhamnose (Y.
What is the size of Yersinia pestis?
Gram negative rod-ovoid 0.5-0.8 µm in width and 1-3 µm in length (safety pin appearance), bipolar staining (Giemsa) facultative intracellular, non-motile.
What is the size of Yersinia pestis bacteria?
Is Yersinia pestis 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.
Does Yersinia pestis have flagella?
Yersinia pestis is nonmotile. Other species are nonmotile at 98.6°F (37°C) but motile at temperatures less than 86°F (30°C) by means of peritrichous flagella. They are aerobic and facultatively anaerobic, oxidase-negative and catalase-positive. They are nonlactose fermenters.
Is Yersinia pestis unicellular or multicellular?
Yersinia pestis is unicellular, placing it in the Bacteria domain. It is classified as a Prokaryotae because of its absence of a nuclear membrane and DNA that is not organized into chromosomes.
Is Yersinia pestis aerobic or anaerobic?
Yersinia are gram-negative bacteria and are described as facultative anaerobes, which means that they are capable of surviving in both aerobic and anaerobic environments.
What are the morphology and characteristics of Yersinia pestis?
MORPHOLOGY AND CULTURE CHARACTERISTICS OF YERSINIA PESTIS (Y. PESTIS) MORPHOLOGY OF YERSINIA PESTIS (Y. Shape – Yersinia pestis is a short, plump, ovoid, rod shape (bacillus) bacterium with rounded ends and convex sides. Size – The size of Y. pestis is about 1.5 mm × 0.7 mm (micrometer).
How does Yersinia pestis spread from person to person?
Yersinia pestis are not rich in nuterients and can grow at temperatures ranging from about 26 Celcius to 37 Celcius. Y. pestis causes diseases through the bite of an infected rat or flea, but can also be transmitted by air. Fleas can become infected by taking the blood of other infected animals.
What is the best temperature to grow Yersinia pestis?
⇒ Optimum temperature – The temperature for the growth of Yersinia pestis ranges from 2–45°C but the optimum temperature for the cultivation in the laboratory is 27°C and usually cultivated at this temperature in laboratories. However, the envelope develops best at 37° C.
Is the Yersinia pestis bacterium motile or non motile?
Motility – Y. pestis is a motile bacterium when in the host body but is non – motile when isolated in the laboratory. Flagella – Yersinia pestis is a flagellated bacterium with a peritrichous flagella arrangement.