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 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 are the characteristics of Yersinia pestis?
Gram-negative bacilli, possible bipolar staining and a “safety pin” appearance. 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.
Is Yersinia pestis a virus or bacteria?
Plague is an infectious disease that affects animals and humans. It is caused by the bacterium Yersinia pestis. This bacterium is found in rodents and their fleas and occurs in many areas of the world, including the United States.
What is the bacteria Yersinia pestis?
Yersinia pestis (formerly called Pasteurella pestis) is a short gram-negative rod that causes plague. It is a disease of rodents (squirrels, rabbits, rats) that is transmitted to humans by flea bites or by person-to-person contact through aerosol inhalation.
How long has Yersinia pestis been around?
Y. pestis is believed to have emerged as a species 5,000–10,000 years ago, but the first known pandemic of plague in humans didn’t occur until the Justinian Plague that afflicted the Byzantine empire about 1,500 years ago. A recent discovery helped us investigate. Scientists successfully recovered DNA from Y.
What biosafety level is Yersinia pestis?
Yersinia pestis [Plague] – BSL-3.
Where is Yersinia pestis found in the world?
The organism that causes plague, Yersinia pestis, lives in small rodents found most commonly in rural and semirural areas of Africa, Asia and the United States. The organism is transmitted to humans who are bitten by fleas that have fed on infected rodents or by humans handling infected animals.
What makes Yersinia pestis so virulent?
“The plague bacterium Yersinia pestis needs calcium in order to grow at body temperature. When there is no calcium available, it produces a large amount of an amino acid called aspartic acid,” said Professor Brubaker from the University of Chicago, USA. “We found that this is because Y.
How long can plague bacteria survive?
How long can plague bacteria exist in the environment? Yersinia pestis is easily destroyed by sunlight and drying. Even so, when released into air, the bacterium will survive for up to one hour, depending on conditions.
Is the bubonic plague still around?
Bubonic plague may seem like a part of the past, but it still exists today in the world and in rural areas of the U.S. The best way to prevent getting plague is to avoid the fleas that live on rodents such as rats, mice and squirrels.
Is Yersinia pestis autotrophic or heterotrophic?
pestis is a chemoheterotroph, meaning that it must consume organic molecules for energy and carbon.
What is Yersinia pestis made up of?
pestis, which consists of more than 20 proteins, is composed of three parts: (i) six effector Yersinia outer proteins (Yops), including YopH, YopM, YopO, YopE, YopJ and YopT, which are translocated into the cytoplasm of eukaryotic cells, (ii) a number of Yops that mediate the delivery of the effector molecules into …
How long did the bubonic plague last?
The Black Death, which hit Europe in 1347, claimed an astonishing 20 million lives in just four years. As for how to stop the disease, people still had no scientific understanding of contagion, says Mockaitis, but they knew that it had something to do with proximity.
Is Yersinia pestis aerobic or anaerobic?
Yersinia pestis, the causative agent of plague, is a pleomorphic, gram negative coccobacillus in the family Enterobacteriaceae. It is an aerobic, facultatively anaerobic, and facultatively intracellular pathogen.
Is Yersinia pestis a pandemic?
The first historically documented pandemic caused by Yersinia pestis began as the Justinianic Plague in 541 within the Roman Empire and continued as the so-called First Pandemic until 750.
What kills Yersinia pestis?
Aminoglycosides: streptomycin and gentamicin
Streptomycin is the most effective antibiotic against Y. pestis and the drug of choice for treatment of plague, particularly the pneumonic form (2-6).
Is Yersinia pestis RNA or DNA?
Yersinia pestis, the etiologic agent of plague, is closely related to Yersinia pseudotuberculosis evolutionarily but has a very different mode of infection. The RNA-binding regulatory protein, Hfq, mediates regulation by small RNAs (sRNAs) and is required for virulence of both Y. pestis and Y.
What color is Yersinia pestis?
Yersinia pestis — Colony Characteristics
Growth at 24 hours is tiny, almost invisible, shiny gray, translucent “spots.” At 48 to 72 hours, colonies are 1 to 2 mm irregular, gray-white to slightly yellow in color, and have a raised, irregular, “fried egg” appearance, which become prominent as the culture ages.
How does Yersinia pestis damage host cells?
pestis against host phagocytes of the innate immune system, thereby allowing it to invade more tissues and organs and cause more severe impairment. Y. pestis carries both invasive factors, which promote contact with and entry into host cells, and antiphagocytic factors that inhibit uptake by host cells.
What is another name for Yersinia pestis?
bacillus Pasteurella pestis (now called Yersinia pestis, renamed after French bacteriologist Alexandre Yersin, who independently discovered the plague bacillus during the Hong Kong epidemic).
Did rats spread the Black Death?
Scientists now believe the plague spread too fast for rats to be the culprits. Rats have long been blamed for spreading the Black Death around Europe in the 14th century.
What are the 2 types of plague?
Plague can take different clinical forms, but the most common are bubonic, pneumonic, and septicemic.
How did humans get the Black Death?
The Black Death is believed to have been the result of plague, an infectious fever caused by the bacterium Yersinia pestis. The disease was likely transmitted from rodents to humans by the bite of infected fleas.
How many died during bubonic plague?
It was believed to start in China in 1334, spreading along trade routes and reaching Europe via Sicilian ports in the late 1340s. The plague killed an estimated 25 million people, almost a third of the continent’s population. The Black Death lingered on for centuries, particularly in cities.
How is Yersinia pestis harmful?
Artificially created aerosol containing plague bacilli can cause numerous and almost simultaneous cases of primary pulmonic plague in an exposed population. Persons exposed would most likely develop severe pneumonia with rapidly progressing respiratory and circulatory failure.
How does Yersinia pestis replicate?
Y. pestis primarily infects wild rodents, and accidental transmission to humans occurs primarily via the bite of an infected flea. The bacteria multiply at the site of the infection and spread to the lymph nodes, which swell and give rise to characteristic buboes.
Is Ebola a virus?
Ebola virus disease (EVD) is a deadly disease with occasional outbreaks that occur mostly on the African continent. EVD most commonly affects people and nonhuman primates (such as monkeys, gorillas, and chimpanzees).
Can the plague live in soil?
As part of a fatal human plague case investigation, we showed that the plague bacterium, Yersinia pestis, can survive for at least 24 days in contaminated soil under natural conditions.
What is the black plague called today?
Understanding the Black Death
Today, scientists understand that the Black Death, now known as the plague, is spread by a bacillus called Yersinia pestis.
How did the Black Death End?
The most popular theory of how the plague ended is through the implementation of quarantines. The uninfected would typically remain in their homes and only leave when it was necessary, while those who could afford to do so would leave the more densely populated areas and live in greater isolation.
Can you get bubonic plague twice?
It is possible to get plague more than once. How do you get plague? It’s usually spread to man by a bite from an infected flea, but can also be spread during handling of infected animals and by airborne droplets from humans or animals with plague pneumonia (also called pneumonic plague).
Why did the black plague spread so easily?
It was a disease spread through contact with animals (zoonosis), basically through fleas and other rat parasites (at that time, rats often coexisted with humans, thus allowing the disease to spread so quickly).
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.
What does Yersinia pestis need to grow?
Pgm Locus Including hms and Ybt. Virulent Y. pestis needs iron for growth and uses the pgm locus to adsorb hemin, which contains ferric iron in the form of ferriprotoporphyrin chloride. It is called pigmentation locus because it is responsible for binding Congo red dye in culture media as well as hemin.
Is Yersinia pestis stationary?
pestis reaches stationary phase. Additionally, all the sRNAs tested in Y. pestis require Hfq for their stability/expression which may explain the severe growth defect displayed by a hfq mutant of Y.
How did Yersinia pestis start?
It is caused by the bacterium, Yersinia pestis. Humans usually get plague after being bitten by a rodent flea that is carrying the plague bacterium or by handling an animal infected with plague.
What is macrophage?
Listen to pronunciation. (MA-kroh-fayj) A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells. Enlarge.
Is Covid 19 the biggest pandemic in history?
While challenging to directly compare, it is likely that COVID-19 will not eventuate as the most damaging pandemic to society, both historically and in the modern age. The other pandemics discussed herein have had significant impacts on societies globally, with larger rates of infection and mortality.
What is the deadliest pandemic in the world?
Plague of Justinian: 30-50 million people (541-549)
It was perhaps the first major outbreak of bubonic plague the world had seen and the record suggests that it extended across continents, reaching Roman Egypt, the Mediterranean, Northern Europe and the Arabian Peninsula.
Was there a plague in the 1500s?
Plague pandemics hit the world in three waves from the 1300s to the 1900s and killed millions of people. The first wave, called the Black Death in Europe, was from 1347 to 1351. The second wave in the 1500s saw the emergence of a new virulent strain of the disease.
How does Yersinia pestis respire?
Y. pestis uses aerobic respiration and anaerobic fermentation to produce and consume hydrogen gas for energy.
What order is Yersinia pestis?
Y. pestis uses aerobic respiration and anaerobic fermentation to produce and consume hydrogen gas for energy.
Does Yersinia pestis have Pili?
Yersinia pestis and many other Gram-negative pathogenic bacteria use the chaperone/usher (CU) pathway to assemble virulence-associated surface fibers termed pili or fimbriae.
When was the 2nd bubonic plague?
The second plague pandemic was a major series of epidemics of plague that started with the Black Death, which reached Europe in 1348 and killed up to half of the population of Eurasia in the next four years. Although the plague died out in most places, it became endemic and recurred regularly.
What were the 3 major plague pandemics?
However, this study goes beyond the genetic analysis of these remains to make claims about the three known plague pandemics: the Justinianic (541–750), the Black Death, which began in the 1340s, and the third pandemic, usually dated from the start of its spread around the globe from Hong Kong in 1894.
What was the first ever plague?
The first recorded case of the plague was in China in 224 B.C.E. But the most significant outbreak was in Europe in the mid-fourteenth century. Over a five-year period from 1347 to 1352, 25 million people died. One-third to one-half of the European population was wiped out!