question

What is pneumococcal meningitis caused by?

answer

Streptococcus pneumoniae

question

Where is Streptococcus found normally?

answer

In the throat. Part of the normal microbiota.

question

This is a Gram+ lancet-shaped coccus. Often seen in pairs.

answer

Streptococcus Pneumoniae

question

Many strains of this bacteria are protected from phagocytosis by a polysaccharide capsule.

answer

Streptococcus Pneumoniae

question

What does Streptococcus pneumoniae commonly cause?

answer

Otitis media, sinusitus, and pneumonia...any of which can precede pneumoncoccal meningitis.

question

What is damage in Meningitis largely due to?

answer

The sever inflammatory response. Causes brain swelling and clots form in capillaries and block blood supply.

question

What is the most deathly form of meningitis?

answer

Streptococcus pneumoniae

question

What is used to treat pneumoncoccal meningitis usually?

answer

Penicillin

question

This bacteria is frequently responsible for epidemics of meningitis.

answer

Neisseria meningitidis

question

Where is Neisseria meningitidis usually found?

answer

commonly part of the normal respiratory microbiota.

question

Symptoms of this are similar to that of pneumococcal meningits, but also may include petechia. (purplish spots on the skin.)

answer

Neisseria meningitidis

question

this can lead to septic (endotoxic) shock

answer

Neisseria meningitidis

question

A gram - encapsulated diploccus. Like Niesseria gonorrhoeae, it can vary in its anitgens and acquire DNA through gene transfer easliy.

answer

Neisseria meningitidis

question

These bacteria attach by pili to mucous membranes and multiply. Proteins in their outer membranes all the bacterial cells to pass through the epithelial lining in the resp tract and into the blood to the meninges. (rare)

answer

Neisseria meningitidis

question

This bacteria releases blebs of the outer membrane and the endotoxin causes vasodilation and capillary leakage leading to drop in blood pressure and septic shock.

answer

Neisseria meningitidis

question

Avoid phagocytosis with capsule

answer

Neisseria meningitidis

question

Person to person transmission via respiratory droplets. Easy transmission in crowded, stressed populations

answer

Neisseria meningitidis

question

Meningitis is the most common result of the food-borne disease of this bacteria

answer

Listeria monocytogenes

question

Infections by this are usually mild in most healthy people. Fever and muscle aches and sometimes nausea or diarrhea.

answer

Listeria monocytogenes

question

Pregnant women who become infected usually miscarry or deliver terminally ill babies.

answer

Listeria monocytogenes

question

A motile, non-spore forming, facultative anaerobis, gram + rod that can grow at 4 degrees celcius. (Can grow on vaccum packed refrigerated foods)

answer

Listeria monocytogenes

question

Mode of entry of Listeria monocytogenes is usually what?

answer

The GI tract

question

These bacteria penetrate the intestinal mucosa through the M cells and into the Peyers patches and into the blood.

answer

Listeria monocytogenes

question

Can be killed with penicillin, but you must catch it quickly, especially in pregnant women.

answer

Listeria monocytogenes

question

This food borne disease can be killed by thouroughly cooking meat. Soft cheeses may carry as well as raw veggies.

answer

Listeria monocytogenes

question

Disfigurement, loss of limbs, and blindness can result from this bacteria.

answer

Mycobacterium leprae

question

Aerobic, rod-shaped, acid fast bacteria. Grows very slowly with a generation time of about 12 days.

answer

Mycobacterium leprae

question

Preferentially infects peripheral nerves. From there the course depends on the persons immune system.

answer

Mycobacterium leprae

question

When the cell-mediated immunity succeffully stops the proliferating bacteria Mycobacterium leprae, the disease is called what?

answer

tuberculoid leprosy

question

When cell-mediated immunity fails to develop or is suppressed.

answer

lepromatous leprosy

question

This bacteria causes a severe form of intoxication that can eventually lead to paralysis.

answer

Clostridium botulinum

question

What does the exotoxin produced by C.botulinum do? What type of toxin is it?

answer

It is an A-B toxin.
The A portion enters the nerve cell and inactivates proteins that regulate the release of neurotransmitter.
The B portion binds to specific receptors on the motor nerve endings.

question

This is a strictly anaerobic Gram +, spore-forming, rod-shaped bacterium that can cause paralysis if you ingest it. (via its' exotoxin)

answer

Clostridium botulinum.

question

There are several types of neurotoxin that Clostridium botulinum produces. What are three that are key to human cases?

answer

The A, B, and E type strains

question

How does Clostridium botulinum produce paralysis?

answer

the toxin attaches to the motor neurons blocking transmission of signals to the muscles.

question

Where does intestinal botulism usually occur?

answer

in infants. (Honey!)

question

In what way does Clostridium botulinum usually cause death?

answer

it causes respiratory paralysis.

question

Epidemic viral encephalitis is usually caused by what?

answer

Arboviruses (arthropod borne viruses)

question

THis is a group of enveloped, single stranded RNA viruses transmitted by insects, mites or ticks

answer

Arboviruses

question

What are some examples of arboviruses?

answer

Lacrosse encephalitis
West Nile encephalitis
eastern and western equinine viruses.

question

What type of bacteria is Staphylococcus aureus?

answer

It is a gram+ cocci in clusters. Coagulase positive. Facultative anaerobes. pyogenic (pus producing)

question

Where does Staphylococcus aureus normally reside?

answer

It is part of the normal microbiota. Up to 20% of healthy people carry it in their nose.

question

What can Staphylococcus aureus cause in the body?

answer

It plays a role in hair follicle infections(boils and carbuncles), Food-borne intoxication, Toxic shock syndrome, and is the leading cause of wound infections.

question

What is the medical significance of Escherichia coli? (E. coli)

answer

Normal microbiota of intestinal tract. Some strains cause
1. urinary tract infections
2. types of intestinal disease
3. some cause meningitis in newborns

question

What type of bacteria is E. coli?

answer

A gram - rod

question

What is an exotoxin?

answer

A protein that a pathogen produces that has very specific damaging effects

question

What does STEC stand for? What is the most common one? What does it cause?

answer

1. Shiga-toxin producing E.coli
2. The most common strain is 0517:H7
3. It causes colonization in the large intestine and leads to Fever, cramps, bloody diarrhea, and some hemolytic uremic syndrome.

question

What are ETEC? What do they cause?

answer

Enterotoxigenic E.coli. THey make pili that allow them to colonize the small intestine. secrete enerotoxins.

question

WHat are EIEC? What do they cause?

answer

Enteroinvasive e coli.
They invade the intestinal epithelium and cause disease similar to shigellosis.

question

What are EPEC? What do they cause?

answer

Enteropathogenic E.coli.
They produce pili that allow them to colonize the small intestine where they inject effector proteins that cause A/E lesions.

question

What are EAEC? What do they cause?

answer

Enteroaggregative E.coli. THey have pili and adhere to intestinal epith. They grow in characteristic aggregations in a thick mucous associatec biofilm. They produce enterotoxins and cytotoxins that damage cells and cause an inflammatory response.

question

DAEC? What do they cause?

answer

Diffusely adhering Ecoli. like EAEC, but they grow as a diffuse layer.

question

What does Streptococcus pyogenes cause?

answer

Strep throat, scarlet fever, wound infections(Flesh-eating disease).

question

What type of bacteria is Streptococcus pyogenes?

answer

a gram + coccus that grows in chains. Characterized by the A carb in the cell wall.

question

What are some of the mechanisms S.pyogenes uses to evade host response?

answer

a special adhesin to attach, M protein which also interferes with phagocytosis,

question

What do Psuedomonas aeruginosa infections cause?

answer

Opportunistic pathogen. Widespread in environment. health-care assoc infections, and outside hospital. Produces two pigments that color wounds green.

question

What type of bacteria is Pseudomonas aeruginosa?

answer

an aerobic, gram- rod with a single polar flagellum.

question

This type of bacteria is a non-invasive, anaerobic gram+ rod that produces am extoxin that prevents inhibitory neurons from releasing their neurotransmitter. (musles contract without control)

answer

Clostridium tetani

question

This is the exotoxin produced by C. tetani

answer

tetanospasm

question

This bacteria causes pain and swelling in wound infections, followed by discharge of a thin brown bubbly fluid and dark discoloration of overlying skin. THe toxin causes tissue necrosis.

answer

Clostridium perfringens

question

This is an alpha toxin producing anaerobe

answer

C. perfringens

question

What does C. perfringens produce?

answer

Clostridial Myonecrosis (Gas Gangrene)

question

How do you avoid/ fix gangrene?

answer

Clean wounds and remove dead tissue asap so that it doesn't have space to produce toxins

question

What are the most common ways wound infections occur?

answer

they happen easily in hospitals where the skin is broken. THey usually happen from normal microbiota of the environment.

question

What are the two bacteria that cause the most wound infections?

answer

S.aureus and S. epidermidis

question

what property of S. epidermidis help it to colonize plastic materials used in medical procedures?

answer

It binds to fibronectin the blood protein that quickly coats surgical implants in the body.

question

This is a Beta- hemolytic gram + chain forming, aerotolerant bacteria

answer

S. pyogenes

question

This protein also binds fibronectin like S.epidermidis. (An F protein)

answer

S. pyogenes

question

Strains of this produce exotoxin A, A superantigen that causes toxic shock and exotoxin B which is a protease that destroys tissue

answer

Strains of S. pyogenes

question

What is the bacteria that causes severe infection in burns that has a greenish tint?

answer

P. aeruginosa

question

This is a gram- facultatively anearobic coccobacillus. Most isolates have capsules. It usually causes infections due to animal bites.

answer

Pasteurella multocida

question

If untreated, bite wounds infected by this bacteria can cause bacteremia leading to endocarditis or meningitis.

answer

Pasteurella multocida

question

Cat scratch disease is caused by this curved, gram- rod.

answer

Bartonella henslae

question

THis is a short, curved, gram-, macroaerophilic bacterium that can cause peptic ulcers. It has multiple polar flagella covred by sheaths.

answer

Helibacter pylori

question

Infection by this bacterium can persist for year or even life. they produce urease(an enzyme that converts urea to ammonia) and burrow within mucous

answer

Helibacter pylori

question

What bacteria causes dental caries?

answer

Streptococcus mutants

question

these are gram+ cocci that live only on teeth.

answer

streptococcus mutants

question

an association of these three bacteria contribute to periodontal disease.

answer

1.porphyromonas gingivalis,2. Treponema denticola and 3.Tannerella forysthia

question

This is a ds enveloped virus that contains linear DNA. There are two types of the virus. One causes oral infections (cold sores) and the other causes genital infections(herpes)

answer

HSV-1 and HSV-2 Herpes Simplex Virus

question

WHy does HSV-1 cause reccurent cold sores?

answer

Because its non infectious DNA persists in sensory nerves and the DNA becomes the source of infectious virions that are carried to the skin or mucous membranes causing sores.

question

this type of toxin involved in intestinal infections causes water and electrolytes to flow from intestinal cells.

answer

enterotoxins

question

This type of toxin in intestinal infections causes cell death. some types can be absorbed into the blood stream resulting in systemic effects.

answer

cytotoxins

question

Characteristic damage caused when bacteria inject proteins that rearrange actin filaments resulting in the replacement of microvilli on the intestinal surface with a thick structure or "pedestal" under the bacterium.

answer

Attaching and effacing (A/E lesions)

question

What is the third way bacterium attack intestinal cells?

answer

through cell invasion. They go into and take over the cell.

question

This bacterium causes potentially fatal diarrhea. (watery diarrhea) Person can lose up to 20 liters a day! Rice water stool. Loss of fluids and electrolytes can cause death without oral rehydration therapy.

answer

Cholera caused by Vibrio Cholerae

question

This bacterium in killed by stomach acid, but if enough are ingested it can get in a produce an enterotoxin that activates ion transport channels causing chloride and other electrolytes to exit the cells.

answer

Vibrio cholerae

question

THis toxin in an A-B toxin. The b portion attaches irreversibly to receptors on the microvilli of epithelial cells ,the a (active) portion enters the cell and activates G prtoeins that usually regulate the in and outs of the cell.

answer

Vibrio cholerae

question

How are most intestinal infections spread?

answer

Via the fecal-oral route

question

These are gram- rods that classically cause dysentery.

answer

Shigella (S. dysenteriae)

question

THis species invades intestinal epithelial cells causing a strong inflammatory response.

answer

Shigella

question

Some strains of this produce a potent cytotoxin known as a shiga toxin(A-B toxin) It is responsible for HUS (hemolytic uremis syndrome)

answer

Shigella dysenteraie

question

This causes red blood cells to break up in tiny blood vessels resulting in anemia and kidney failure

answer

HUS (hemolytic uermic syndrome)

question

What two things can cause HUS?

answer

Shigella dysenterae and some E coli strains

question

This bacterium is not motile by itself but over takes the actin of the cells it invades and causes the cells to run into other cells and spread infection

answer

shigella syseteriae

question

This is a gram- rod that induces uptake by epithelial cells in the region btwn th esmall and large intestine. Bacteria multiply in the phagosome and then discharge at the base of the cell. inflammatory response increases fluid secretion.

answer

Salmonella enterica (S. enterica)

question

Ingestion of food contaminated by animal feces, especially poultry

answer

samlmonella enterica

question

What are typhoid and paratyphoid fever caused by?

answer

Typhoid fever is caused by Salmonella serotype Typhi. Paratyphoid fever by Salmonella serotype paratyphi

question

These are gram- members of the Enterobacteriaeceae family. They are serotypes of Salmonella

answer

typhi and paratyphi

question

This bacterium is a curved gram- microaerophilic rod

answer

Campylobacter jejuni (C. jejuni)

question

This bacterium has a low infected dose the bacteria multiplies within and beneath the epithelial cells causing inflammatory response.

answer

C. jejuni (Campylobacter jejuni)

question

This is a gram+, rod that is endospore forming and an obligate anaerobe. The endospores are highly resistant to common disinfectants.

answer

C. difficile (Clostridium difficile)

question

This bacteria has toxins that disrupt host cell actin, causing lethal effects to the intestinal epithelium.

answer

C. difficile

question

This disease primarily occurs in hospitalized patients on antibiotic therapy

answer

C. difficile (CDAC-Clostridium difficile associated disease.)

question

These type of virus account for nearly 500,000 deaths of children worldwide due to lack of fluid replacemtn

answer

rotavirus

question

These are naked viruses with double walled capsid and double stranded segmented RNA

answer

rotavirus

question

THese are naked, SS RNA viruses that are the most common cause of viral gastroenteris in the US.

answer

norovirus

question

This virus causes abdominal cramping vomiting and diarrhea lasting 12 to 60 hrs

answer

Norovirus

question

This is a naked, ss RNA virus of the picornavirus family. It usually has mild symptoms, but often prolonged full recovery. Vaccine is available

answer

Hep A

question

This is an enveloped DS DNA hepadnavirus that is transmitted through blood and semen. It often has acute symptoms and if chronic can lead to cirrhosis and cancer

answer

Hep B

question

This is an enveloped, SS RNA flavavirus . It has no vaccine. It usually has few symptoms, but liver damage can lead to cirrohsis and cancer

answer

Hec C

question

WHen an infection becomes ______, it means that it has been carried to all parts of the body, producing disease in one or more vital organs.

answer

Systemic

question

Illness that results from a circulating agent or its toxins

answer

sepsis (blood poisoning)

question

When a substance is circulating in the blood stream, the condition is given that specifies the nature of the substance. Ex?

answer

bacteremia, viremia, fungemia (Does not necessarily mean disease)

question

WHen sepsis causes blood pressure to fall to such low levels that blood flow to vital organs is insufficient.

answer

septic shock

question

This term is used to describe infections of the heart valves or the inner surfaces of the heart.

answer

endocarditis

question

This starts suddenly with a fever and is usually caused by virulent species such as S. aureus and S. pneumoniae. Can infect normal and abnormal heart valves.

answer

Acute bacterial endocarditis

question

This is an infection of the heart valves and inner surfaces of the heart that is slower and not usually caused by virulent species. (less likely to be fatal)

answer

subacute bacterial endocarditis (SBE)

question

Where do bacteria in SBE come from usually?

answer

from dental procedures, tooth brushing, trauma.

question

What usually causes SBE?

answer

Staphylococcus epidermidis and other normal microbiota of the skin or mouth

question

Why do the microbes live in the heart valves?

answer

They get caught in thin blood clots formed around deformes heart valves or other areas with disturbed bloodflow. They multiply and create a biofilm.

question

How does a biofilm evade host immune response?

answer

They are protected from phagocytosis and antimicrobial medications.

question

How does SBE lead to sickness?

answer

The bacteria continually wash off into the bloodstream and pieces of the infected clot can break off and block important blood vessels which can lead to death of tissue.

question

This is a component of the outer membrane of the gram- cells that can cause symptoms such as fever and shock. Lipid A is responsible for the effects of this

answer

endotoxin

question

The most fatal cases of sepsis usually involve gram ____ bacteria like E.coli P. aeruginosa and other Enterobacteriacea species .

answer

gram negative bacteria

question

What is sepsis initially caused by?

answer

It usually begins with an infection somewhere in the body other than the bloodstream. It is initially due to and overstimulation of the inflammatory response.

question

Widespread clotting often associated with Sepsis and often accompanied by hemorrhage.

answer

Disseminated intravascular coagulation. (DIC)

question

What are the steps of sepsis?

answer

1. TLRs on macrophages and neutrophils detect endotoxin or other PAMPs, and phagocytess release pro-inflammatory cytokines. WHen this occurs systemically, a cytokine storm results and further activation of the complemnet system.

question

Bacteriocidcal antibiotics often lyse bacterial cells and release more endotoxin, resulting in worsening of this blood infection.

answer

Sepsis

question

What are some of the effects of sepsis?

answer

fever, impaired oxygen exchange, increased leakage of plasma from blood vessels, tissue damage from clotting, etc...

question

This disease is widespread in the US and found in rabbits, muskrats, and bobcats.

answer

Tularemia

question

This organism causes Tularemia

answer

Francisella tularensis

question

This is a non-motile, aerobic, Gram- rod that enters through breaks in the skin or mucous membranes and is carried to the regional lymoh nodes making them large and tender.

answer

Francisella tularensis

question

THis organism is ingested by phagocytic cells and grow within them, then spread throughout the body

answer

Francisella tularensis

question

This organism is considered a category A risk for bioterrorism.

answer

Francisella tularensis

question

This

answer

question

This is a part of the family Enterobacteriaceae, is a gram- rod, and is facultatively anaerobic. It is non motile and is spread widely through fleas.

answer

Yersinia pestis (Plague)

question

If transmitted through fleas, Y. pestis results in ______ ______.
If spread through inhalation, Y.pestis results in _______ ________.

answer

1.bubonic plague
2. pneumonic plague

question

If Y.pestis spread via the bloodstream, the person may develop ____ ______. Which could lead to DIC (disseminated intravascular coagulation)

answer

septicemic plague

question

This organism forms biofilms in the diegestive tract of infected fleas so that when they try to feed, they actually regurgitate the bacteria into the bite wound

answer

Yersinia pestis (plague)

question

This is a ds DNA virus of the herpesvirus family.

answer

EBV Epstein-Barr virus

question

What disease does EBV cause?

answer

Mono

question

This virus infects the mouth and throat and then becomes latent in another cell type.
After that, it is carried to the lymph nodes where is infects B lymphocytes where it can produce a productive or latent infection.

answer

Epstein-Barr Virus

question

This is a mosquito born viral disease similar to, but milder than yellow fever. It is caused by a ss RNA virus that has 4 closely related serotypes.

answer

DENV1, DENV2, DENV3, DENV4. (dengue fever)

question

This is transmitted primarily by the Aedes family of mosquitos

answer

Dengue fever

question

THis is generally self-limiting and rarely fatal, but a severe form of the disease can occur in patients who experience a second infection of the dengue virus.

answer

1.Dengue fever
2. Dengue hemororrhagic fever

question

In this model, preexisting (dengue) antibodies from a primary dengue infection recognize the virus and bind to them forming immune complexes. However, because they are for a different serotype, they instead facilitate viral entry into cells that express Fc receptors and more freely replicate in macrophages.

answer

Antibody-dependent enhancement (ADE)

question

This is an emerging disease and the fastest spreading mosquito-born viral disease in the world currently.

answer

Dengue fever

question

This is a sickness caused by a virus that is transmitted by mosquitoes of the Aedes family, similar to dengue fever. It is an alphavirus in the family of Togaviridea.

answer

CHIK

Microbiology Final Exam Test Questions – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards