Microbiology Chapters 21-24

Compare and contrast bacterial vs viral infections of the CNS. In particular, discuss the various portals of entry, symptoms, treatment, and prevention.

- Examples of bacterial infections include whooping cough, strep throat, ear infection and urinary tract infection (UTI). -Viral infections include the common cold, flu, most coughs and bronchitis, chickenpox and HIV/AIDS. -Doctors usually treat bacterial infections with antibiotics. -Viral: managing symptoms, using antiviral medicines, preventing infection in the first place

Explain how colonization of the nasopharynx can facilitate transmission to the meninges and cause meningitis.

-A multi-step process that reflects the ability of bacterial pathogens to cross the oropharyngeal or digestive mucosal barrier, survive and replicate in the bloodstream, and to eventually cross the BBB.

Explain several reasons why salmonellosis can be such a widespread problem in the community.

-Acid-resistant -Incubation: 5-21 days -Invade the small intestine -S. typhi is transmitted by the five Fs: a)Flies b)Food c)Fingers d)Feces e)Fomites -Salmonellosis can be contracted from a variety of foods. -Salmonellosis is usually caused by S. enterica serotype Enteritidis or Typhimurium. -Salmonella serotypes are often found in unpasteurized milk or poultry products. -They can also be transmitted by live animals.

Infectious Diseases of the Oral Cavity Can Affect One's Overall Health. Write a paragraph explaining the importance of dental hygiene and the potential results of not maintaining hygiene.

-Acidogenic bacteria form biofilms (plaques) and ferment dietary carbohydrates into acids that attack enamel. --Dental caries --Periodontal disease: Gingivitis and Periodontitis -Poor oral hygiene leads to increased subgingival plaque, which can be populated by bacteria.

The Resident Microbiota of the Digestive System Is Enormous. Assess the effectiveness of the chemical, mechanical, and cellular defenses, including the digestive microbiome in preventing bacterial colonization.

-Chemical barrier: pH, bile, lysozymes,... -Mechanical barrier: mucus, wall of tract, flow of food content,... -Cellular barrier and Innate: IgA, Peyer patches of MALT,... -Digestive microbiome: antimicrobial agents, competition against nutrients, niches

Using your knowledge of C. difficile pathology and the human microbiome, hypothesize why fecal transplants are such an effective treatment for C. difficile infections.

-Fecal transplant for dysbiosis caused by broad spectrum antibiotics -The microbiota of mouth and large intestine represent extremely complex communities.

Who is most vulnerable to Clostridium difficile infections, and why are these infections so difficult to treat?

-Humans because of food poisoning through meat, poultry, and fish -Because they require a high infectious dose and take 8-24 hours to appear

Describe the most common ways that food and water contamination occur. What can be done to prevent it?

-Improper slaughter procedures -Food washed with contaminated water -Infected humans can infect food through the fecal-oral route -Wash hands, wear gloves, wash food before use

Describe how Mycobacterium leprae is spread and progresses.

-It is spread through nasal secretions -It progresses by: --disfigurement of skin and bones --twisting of limbs and curling of fingers --loss of facial features -Treatment is a dapsone combination

Using West Nile virus, prepare a drawing illustrating how the primary transmission cycle is linked to incidental infections in humans.

-Mosquito will bite an infected animal -The virus will circulate for a few days before settling in the salivary glands -Mosquito will then bite a human or larger animal -Human will become infected when mosquito inserts the virus into the bloodstream

Propose what precautions should be taken for someone who has been bitten by a dog that is believed to be rabid.

-Post-exposure immunization with the rabies vaccine can be done immediately after exposure. -Passive immune therapy with antirabies antibodies

Some Bacterial Pathogens Cause Foodborne Intoxications. Illustrate the types of precautions one might take to guard against the possibility of foodborne intoxications.

-Staphylococcal food poisoning --Food is often contaminated by ---boils or abscesses on a handler's skin ---through sneezing -Clostridial food poisoning --C. perfringens: Obligate anaerobe, Gram + rods, endospore forming -Proper handling, refrigeration, and heating help decrease the risk of contamination.

Distinguish between the two types of African sleeping sickness in terms of organisms, transmission, symptoms, and geography.

-T. brucei var. gambiense: chronic form of african sleeping sickness; bouts of fever, headaches, changes in sleep patterns and behavior, wasting, possible coma -T. brucei var. rhodesiense: acute form of african sleeping sickness; high fever and rapid coma preceding death -Both are transmitted by the tsetse fly

Judge how the structure of the nervous system attempts to protect itself from infection without having an indigenous microbiota.

-The Nervous System Is Composed of the Central and Peripheral Nervous Systems -The brain has a blood-brain barrier that controls what substances can enter the CNS.

Describe the anatomy and physiology of the nervous system. Relate its structure and function to the symptoms observed in meningitis and encephalitis.

-The Nervous System Is Composed of the Central and Peripheral Nervous Systems The brain has a blood-brain barrier that controls what substances can enter the CNS. The nervous system lacks an indigenous microbiota. -Meningitis: Sudden high fever,Headache and vomiting, Stiff neck, Coma and death (if left untreated), Deafness, Blindness, Paralysis -Encephalitis is an acute inflammation of the brain, pain in the head and neck, convulsions, coma

Compare and contrast the concept pairs listed below. Explain why these distinctions are clinically relevant. 1) Intoxication vs infection. 2) Toxic dose vs infectious dose

1) Intoxication: illnesses in which bacterial toxins are ingested with food and water. Infection: illnesses in which live bacterial pathogens are ingested and grow in the body. 2) Toxic dose: minimal dose required to produce adverse effects Infectious dose: the amount of pathogenic organisms that will cause infection in susceptible subjects

Digestive System Infections and Intoxications Can Be Caused by Viruses and Eukaryotic Microbes. Write comparative paragraphs describing the salient characteristics of hepatitis A and hepatitis E.

1. Hep A: Hep A Virus, nausea, vomiting, low-grade fever, indirect through food and raw shellfish, no specific treatment 2. Hep E: Hep E Virus, Nausea, muscle pain, low-grade fever, indirectly through water zoonosis, no effective treatment

GI Tract Pathogens Are Usually Spread Through Food and Water. Assemble a list of ways that food and water can become contaminated with bacterial-contained fecal matter.

1. Meat can be contaminated during improper slaughter procedure. 2. Fruits and vegetables can be washed with contaminated water. 3. Infected humans can contaminate food they handle through the fecal-oral route. 4. Infected humans can contaminate drinking water through the fecal-oral route.

Name and describe four different viruses that can be causes of viral gastroenteritis.

1. Rotavirus: can be a deadly infection in children. -dsRNA -Winter diarrhea -Fecal-oral route 2. Norovirus: is most deadly for children, adults over 65. -ssRNA 3. Hepatitis A virus:) belongs to the Picornaviridae family. -It is commonly transmitted by food or water contaminated by the feces of an infected individual. -Transmission can also occur by raw shellfish. 4. Hepatitis E virus: is an opportunistic, emergent disease. -It is caused by a member of the Caliciviridae family. -Young adults and pregnant women are most susceptible.

Distinguish between the typical symptoms of the following protozoal intestinal diseases: amoebiasis, giardiasis, balantidiasis, and cryptosporidiosis.

1. amoebiasis: Bloody stools, stomach pain, and cramping 2. giardiasis: nausea, gastric cramps, flatulence, foul-smelling watery diarrhea 3. cryptosporidiosis: watery diarrhea, dehydration, vomiting, nausea, stomach cramps, fever, and malaise

Compare staphylococcal food poisoning and salmonellosis with respect to causative organism, symptoms, incubation period, diagnosis, transmission method, sources, and other germane criteria.

1. staphylococcal food poisoning: -S. aureus, abdominal cramps, nausea, diarrhea, vomiting, foodborne, illness usually resolves without treatment 2. salmonellosis: -Salmonella serotypes, fever, diarrhea, vomiting and abdominal cramps, foodborne, fluid replacement antibiotic therapy

Differentiate between cryptococcal meningoencephalitis and Toxoplasmosis

=CM: -Symptoms: fever, headache, change in mental status -Transmission: infected bird droppings -Treatment: vaccine -Prevention: avoid bird droppings and birds; avoid dusty environments in endemic areas =T: -Symptoms: asymptomatic -Transmission: contact with contaminated cat feces; indigestion of contaminated food, water, or formites -Treatment:Antibiotics/vaccine -Prevention: practice good hygiene; avoid raw or uncooked meat and unpasteurized goat milk

Explain how such a small virus like the polio virus can cause such destruction on infecting a human that the disease may be life threatening.

=Transmission: Fecal-oral route =Multiply in: -gastrointestinal tract -lymph tissue -tonsils =Clinical types: 1. Abortive polymyelitis: Not neuroinvasive 2. Nonparalytic: Sometimes the viruses pass through the bloodstream to the meninges. 3. Paralytic: Paralysis of limbs and trunk.

Differentiate between cryptococcal meningoencephalitis and coccidioidal meningitis

=cryptococcal meningoencephalitis: -Fever, headache, change in mental status -Transmitted via the airborne bird droppings =coccidioidal meningitis: -Stiff neck, severe headache, nausea, vomitting -Transmitted by inhalation of spores

The central nervous system is surrounded by

All of the choices are correct

Eukaryotic parasite infections of the digestive system are associated with

Amoebiasis, ascariasis, cysticercosis, flatworm, giardiasis, roundworm, tapeworm, trichinellosis (trichinosis), hookworm disease

Many grains, peanuts, and hay can become contaminated with fungi that produce powerful toxins called aflatoxins. These toxins are produced by

Aspergillus flavus

Systemic viral diseases

Burkitt lymphoma, cytomegalovirus disease, dengue (breakbone) fever, dengue hemorrhagic fever

Bacterial gastrointestinal infections are associated with

C. difficile infection (CDI), campylobacteriosis, cholera, Shiga toxin, Shiga toxin-producing E. coli (STEC), Shigellosis, vibriosis

This is the causative agent of the most commonly reported bacterial foodborne illness in the United States.

Campylobacter jejuni

Which of the following bacteria does not cause foodborne intoxications?

Clostridium difficile

_______________ is typically found in healthcare settings. Symptoms include diarrhea and pseudomembranous colitis.

Clostridium difficile

Protozoal diseases affecting the nervous system involve

Correct primary amoebic meningoencephalitis (PAM), toxoplasmosis, African trypanosomiasis (sleeping sickness)

___________ is an inflammation of the brain.

Encephalitis

Compare and contrast meningitis and encephalitis. Which do you find most deadly? Is one more difficult to treat than the other?

Encephalitis; there is not a specific vaccine or treatment for this

Which one of the following conditions is not caused by Clostridium botulinum?

Inability to relax contracting muscles

Distinguish the clinical symptoms that might be of value in the diagnosis of botulism and listeriosis.

L- headache, stiff neck, confusion, loss of balance, convulsions B- foodborne and wound, difficulty swallowing, slurred speech, blurred vision, trouble breathing, flaccid paralysis

To identify microorganisms present in the cerebrospinal fluid, a ____________ is performed.

Lumbar puncture

A large number of cholera bacilli must be present in contaminated food for infection to be established because

Most will be destroyed by the stomach acid

Which of the following bacteria directly or indirectly injure periodontal tissues?

Porphyromonas gingivalis

Where can one pick up trichinosis?

Raw or poorly cooked pork

Identify the method of reproduction displayed by the tapeworms and compare it to the method employed by roundworms.

Roundworms: sexual reproduction between hermaphroditic and gender-specific species Tapeworms: sexual and asexual reproduction because they are hermaphroditic

Which of the following agents is transmitted through contaminated meat and eggs, and therefore can be spread by household pets that lay eggs, like ducks, tortoises, and iguanas?

Salmonella enterica

Travelers to regions of the world where cholera is endemic

Should only drink treated water

Create a list of bacteria that produce enterotoxins. For each bacterium, also list what disease it causes.

Streptococcus pyogenes: pharyngitis, tonsillitis, scarlet fever, cellulitis, erysipelas, rheumatic fever, post-streptococcal glomerulonephritis Staphylococcus aureus: staphylococcal food poisoning

Compare and contrast tetanus and botulism. For each, make sure to discuss the causative agent, mechanism of action, symptoms, treatment, and prevention.

Tetanus: Clostridium tetani; muscle stiffness in jaw and neck, trismus; wounds contaminated with soil, dust, and animal feces; tetanus antitoxin, penicillin; immunizing with toxoid vaccine Botulism: Clostridium botulinum; foodborne and wound, difficulty swallowing, slurred speech, blurred vision, trouble breathing, flaccid paralysis; contaminated canned food, contaminated wounds, consuming spores; antitoxin, breathing assistance; practicing good home canning, preparing and storing food properly, avoiding honey (infants)

Which of the following statements about Echinococcus granulosus is correct?

The definitive host is the dog and the intermediate host is a man.

Which of the following characteristics does not apply to Salmonella serotypes?

They can cause skin infections.

Which of the following is not a characteristic of giardiasis?

Transmission occurs by tick bites.

_____________causes an invasive gastroenteritis, primarily in children. Cells destroy tissue in the ileum and multiply in Peyer patches.

Yersinia enterocolitica

Viral diseases affecting the CNS involve

abortive poliomyelitis, arboviral encephalitis, aseptic meningitis, polio (poliomyelitis), rabies

Bacterial infections affecting the CNS involve

acute bacterial meningitis (ABM), Haemophilus meningitis, listerial meningitis, listeriosis, meningococcal meningitis

Circulatory diseases caused by bacterial species invlove

anaplasmosis, acute endocarditis, bacteremia, brucellosis (undulant fever), bubonic plague, bull's-eye rash, infective endocarditis, inhalational tularemia

The early signs and symptoms of campylobacteriosis

are not unique

Diseases of the oral cavity are associated with

biofilm, dental caries, dental plaque, enamel, gingivitis, periodontal disease, periodontitis

One of the distinctive characteristics of Yersinia pestis is

bipolar staining

Nervous system anatomy involves

blood-brain barrier, cerebrospinal fluid (CSF), "immune privileged" , meninges, microglia, neuron neurotransmitter, peripheral nervous system (PNS)

All the following may be symptoms of tularemia except

bloody urine

Bacterial intoxication affecting the CNS involves

botulism, wound botulism, tetanus, infant botulism, tetanospasmin

Salmonellosis is

caused by several serotypes of Salmonella.

Fungal infections affecting the nervous system involve

chronic meningitis, coccidioidal meningitis, coccidioidomycosis, cryptococcal meningoencephalitis, cryptococcosis, cryptosporidiosis, cyclosporiasis

Bacterial foodborne intoxications are associated with

clostridial food poisoning, staphylococcal food poisoning, enterotoxin, exotoxin

The side-effects of broad-spectrum antibiotic therapies are associated with

dysbiosis, C. difficile infection (CDI), human microbiome, pseudomembranous colitis

The _______________ lines the heart chambers and valves, and can be a target for microbial infections.

endocardium

In cases of giardiasis, the flagellated protozoa accumulate at the base of the brain and induce a deep coma in the patient.

false

Mortality rates in outbreaks of rabies tend to be low, even if the vaccine is not administered.

false

Naegleria is thermophilic and causes a deadly form of encephalitis.

false

The noroviruses are notable for the serious diseases of the central nervous system.

false

Viral meningitis is also called "aseptic meningitis" because bacteria are also present in the cerebrospinal fluid.

false

Infant botulism is also called

floppy baby syndrome

The central nervous system

has microglial cells to provide protection from infection.

Some forms of encephalitis are due to ___________________.

herpesviruses

A patient that lives in the northeastern U.S. complains of a growing rash where the lesions looks like a "bulls-eye" and is not itchy like a mosquito bite. Symptoms include fever and other flu-like symptoms. Which of the following is the best diagnosis?

lyme disease

_______________ filter the lymph that passes through the lymphatic system.

lymph nodes

Haemophilus influenzae is currently recognized as an important cause of

meningitis

Which of the following are symptoms of tetanus?

muscle stiffness

Once the symptoms have fully materialized in an individual, rabies has

one of the highest mortality rates of any human disease.

In the most serious form of polio, the virus infects the brain. Nerves are affected throughout the body, which can lead to paralysis. This form of polio is known as

paralytic poliomyelitis

Transmission of arboviruses can be reduced by

preventing mosquito bites

Another name for tularemia is

rabbit fever

The hepatitis A virus

results in liver damage

_____________ cause(s) bladder infections that produce bloody urine and painful urination.

schistosoma parasites

Erythema migrans (EM) is the distinctive skin lesion

that appears with lyme disease

The protozoal disease cryptosporidiosis is characterized by

transmission through contaminated water

Antibiotics are effective against tetanus, but not for botulism

true

B. cereus causes a GI intoxication

true

Severe cases of amoebiasis result in the microbe penetrating the intestinal wall and entering the bloodstream.

true

The causative agent of Valley Fever can also cause fungal meningitis.

true

The incubation periods for hepatitis A and hepatitis B are different, as are the viruses responsible for these diseases.

true

The life cycle of hookworms involves only a single host.

true

The most prevalent helminthic infection in the United States is from pinworms.

true

The vaccine for hepatitis B is made from hepatitis B surface antigens.

true

Transmission of hepatitis B usually involves direct or indirect contact with an infected body fluid such as blood, urine, saliva, or semen.

true

West Nile virus is an arbovirus.

true

Systemic protozoal diseases

trypanosomiasis, malaria (black-water fever), American trypanosomiasis (Chagas disease), babesiosis

Circulatory diseases caused by eukaryotic parasites.

trypanosomiasis, malaria (black-water fever), lymphangitis, elephantiasis, American trypanosomiasis (Chagas disease), babesiosis

A disease spread by ticks and causing skin ulcers is

tularemia

H. pylori secretes ______, which allows it to survive the acidic environment of the stomach.

urease

Viral infections of the digestive system are associated with

viral gastroenteritis, rotavirus gastroenteritis, norovirus gastroenteritis, hepatitis A, hepatitis E

Hansen's disease is difficult to diagnose, in part because it has an incubation period of 3 to 6

years