3 MICROBIAL YOU Flashcards
What is the most abundant element in the atmosphere?
Nitrogen
What role do bacteria play in nitrogen conversion?
They convert nitrogen into useful forms like ammonia.
What percentage of calories do microbes provide to humans?
About 10 percent
How many digestive enzymes do humans produce compared to bacteria?
Humans produce twenty; bacteria produce ten thousand.
What is horizontal gene transfer?
The process by which bacteria swap genes among themselves.
How quickly can E. coli reproduce?
Seventy-two times in a day.
What is the estimated weight of microbes in a human body?
About three pounds.
True or False: Each human has ten times more bacterial cells than human cells.
False
What is the approximate number of bacterial cells in a human body?
Between thirty and fifty trillion.
What term describes benign microbes living inside us?
Commensals
What is the total number of microbes known to cause disease in humans?
1,415
What are archaea?
A separate branch of life that causes no known diseases in humans.
Fill in the blank: A virus is a piece of bad news wrapped up in a _______.
[protein]
What is the size comparison between viruses and bacteria?
Viruses are much smaller than bacteria.
Who is credited with coining the term ‘virus’?
Martinus Beijerinck
How many species of viruses are known to infect mammals?
586
What did Lita Proctor discover about viruses in seawater?
A quart of seawater contains up to 100 billion viruses.
What is Pithovirus sibericum?
A virus discovered in permafrost that can spring into action after thousands of years.
What virus causes chickenpox and can later result in shingles?
Varicella-zoster virus
What is the common cold caused by?
A family of symptoms generated by multiple viruses.
What is the primary type of virus causing the common cold?
Rhinoviruses
What was the purpose of the Common Cold Unit in Britain?
Researching the common cold.
How many varieties of rhinoviruses exist?
About one hundred.
What was used to simulate the spread of a pathogen in the volunteer study?
A dye visible only under ultraviolet light
The study illustrated how germs can spread through social interaction.
How many times does the average adult touch their face in an hour?
Sixteen times
Each touch can transfer pathogens to various surfaces.
What was discovered about the transmission of cold germs in a study at the University of Wisconsin?
Kissing was found to be almost wholly ineffective in spreading cold germs
Transmission was primarily through physical touch.
Where do microbes thrive in subway trains according to a survey?
In the fabrics on seats and on plastic handgrips
Metal poles were found to be a hostile environment for microbes.
How long can flu virus survive on paper money if accompanied by nasal mucus?
Two and a half weeks
Without nasal mucus, survival is typically only a few hours.
What are the two main groups that fungi are divided into?
Molds and yeasts
Fungi are more closely related to animals than to plants.
What is Candida albicans responsible for?
Thrush
It can invade deeper parts of the body and cause serious infections.
What disease is caused by Cryptococcus gattii?
Serious lung and brain infections
This fungus developed virulence in 1999.
What is valley fever also known as?
Coccidioidomycosis
It primarily occurs in California, Arizona, and Nevada.
What are protists?
Anything that isn’t obviously plant, animal, or fungus
They include amoebas, parameciums, and diatoms.
What notable protist is responsible for malaria?
Plasmodium
Other diseases caused by protists include toxoplasmosis and giardiasis.
What was the Bradford coccus initially identified as?
A new bacterium
It was later recognized as a new type of virus.
What did Timothy Rowbotham discover in 1992?
A microbe unlike anything previously seen
This discovery changed the field of microbiology.
What is mimivirus known for?
Being much larger than any previously known virus
It has over a thousand genes.
What significant event occurred with the cooling tower related to mimivirus?
It was demolished, losing the only known colony of the virus
This occurred in the late 1990s.
What did the team led by Jean-Michel Claverie discover in 2013?
Pandoravirus, a giant virus with 2,500 genes
This virus contains 90% of genes not found elsewhere in nature.
Who was Robert Koch?
A German microbiologist who reported cholera was caused by a bacillus
His findings contributed to the germ theory of disease.
What was Salvarsan used to treat?
Syphilis
It had many drawbacks, including toxicity.
What did Alexander Fleming discover in 1928?
Penicillin
This discovery was accidental, stemming from mold contamination.
What is the significance of penicillin in medicine?
It was the first true antibiotic that effectively treated bacterial infections
It revolutionized the treatment of infectious diseases.
What challenge did Howard Florey face while producing penicillin?
It was very hard to produce in clinically useful quantities
Significant resources were needed to extract it from mold.
What tragic event occurred during the trial of penicillin on Albert Alexander?
He relapsed and died due to a shortage of penicillin
His case illustrated the vulnerability of humans to infections before antibiotics.
What was the initial effect of penicillin on Alexander?
Miraculous; he was sitting up and looking almost back to normal within two days.
This highlights the initial effectiveness of penicillin in treating infections.
What happened to Alexander after the supplies of penicillin were exhausted?
He relapsed and died.
This illustrates the critical importance of consistent antibiotic supply for effective treatment.
Where did the quest to produce bulk penicillin move during World War II?
U.S. government research facility in Peoria, Illinois.
This shift was necessary due to Britain’s preoccupation with the war.
Who discovered the potent mold that led to the mass production of penicillin?
Mary Hunt.
She brought in a cantaloupe with a mold that was two hundred times more potent than previously tested molds.
What was the outcome of American pharmaceutical companies after the discovery of the potent mold?
They produced 100 billion units of penicillin a month within a year.
This rapid production marked a significant advancement in antibiotic availability.
How many honors did Alexander Fleming receive for his contributions?
189 honors of all types from around the world.
This includes his Nobel Prize in Physiology or Medicine shared with Ernst Chain and Howard Florey.
What caution did Fleming express during his Nobel acceptance speech?
Microbes could easily evolve resistance to antibiotics if carelessly used.
This warning has proven to be prescient in light of current antibiotic resistance issues.
What is the elemental weakness of penicillin?
It can stimulate the evolution of antibiotic-resistant bacteria.
Antibiotics are broad-spectrum and can wipe out both harmful and beneficial microbes.
How many courses of antibiotics do most people in the Western world receive by adulthood?
Between five and twenty courses.
This cumulative effect raises concerns about microbial resistance.
What severe condition did Michael Kinch’s son develop?
A ruptured appendix and subsequent peritonitis.
This case highlights the serious consequences of antibiotic-resistant infections.
What alarming discovery was made regarding Kinch’s son, despite his limited antibiotic history?
He had gut bacteria that were resistant to antibiotics.
This indicates that resistance can develop even in individuals with minimal antibiotic exposure.
What is the trend in new antibiotic introductions since the 1990s?
Roughly one new antibiotic every other year.
This is a significant decline compared to the three introduced annually from the 1950s to the 1990s.
What percentage of antibiotic prescriptions in the U.S. are for conditions that cannot be cured with antibiotics?
Almost three-quarters.
This misuse contributes to the rise of antibiotic resistance.
What is the fate of the typical case of pneumococcal pneumonia treatment from 1945 to today?
It now requires more than twenty million units of penicillin per day due to resistance.
This demonstrates the increasing challenge of treating bacterial infections.
What is MRSA?
Methicillin-resistant Staphylococcus aureus.
MRSA is a drug-resistant strain that evolved shortly after the introduction of methicillin.
What is the annual death toll attributed to MRSA and its cousins?
Estimated 700,000 people worldwide.
This underscores the severity of antibiotic resistance as a global health crisis.
What is the projected impact of antimicrobial resistance by 2050?
Forecast to lead to ten million preventable deaths a year.
This projection emphasizes the urgent need for action against antibiotic resistance.
What are quorum-sensing drugs designed to do?
Keep bacterial populations below the threshold that triggers an attack.
This approach aims to disrupt bacterial communication without killing them.
What are bacteriophages?
Viruses that target specific bacteria.
They offer a potential alternative to antibiotics, making it harder for bacteria to evolve resistance.
What is the current state of the antibiotics crisis according to Kinch?
It is not a looming crisis; it is a current crisis.
This reflects the urgent reality of antibiotic resistance as demonstrated by personal experiences.
What was the initial purpose of antibiotics in agriculture?
To fatten farm animals.
This agricultural use of antibiotics has contributed to human exposure and resistance.
