Micro Exam 4 HW
B) Explain why we do we not vaccinate against Strep. Pyogenes.
Antibodies for some versions of the M protein cross react with our heart valves causing an autoimmune disorder known as rheumatic fever.
Secondary syphilis is characterized by the appearance of _____. A) gummas B) a rash C) a chancre
B) A Rash
List the causative agent and morphology (shape & arrangement) for each of the following diseases: 1 Rocky Mountain spotted fever 2 Lyme Disease 3 Plague 4 Anthrax
B) Shape and Arrangement 1 G-, small cocobacili 2 G-, helical shaped spirochete 3 G-, bacillus/rod 4 G+, bacillus, in chains, endospore forming
Which of the following is/are virulence factors seen in strains of Staphylococcus aureus? Select all that apply. A) Lipopolysaccharide (maybe not sure) B) Superantigens (has to do with TSS) C) Staphylokinase D) Enzymes to clot blood E) Exfoliative toxin
B) Superantigens (has to do with TSS) C) Staphylokinase D) Enzymes to clot blood E) Exfoliative toxin (has to do with scalded skin)
Why do villagers not boil water before drinking?
Boiling is not as common because fuel wood is in short supply and very costly
True or False? The M protein enhances the virulence of Streptococcus by preventing phagocytosis
True *In A-B exotoxins, the A component binds to the host cell receptor so that the B component can enter the cell. Biofilms provide pathogens with an adhesion mechanism and aid in resistance to antimicrobial agents.
True or False? Cystitis is another term for a kidney infection
False *Cystitis is inflammation of the bladder and only 25% of cases lead to kidney inflammation
Examine the graph to the right, which shows the results of an experiment comparing the incidence of cholera in villages that do not filter their water (control), filter water through a folded sari (cloth garment, 20μm mesh) or filter water through nylon mesh (150μm mesh). How would you interpret these results? Does filtration work?
Yes, filtration can reduce the cases of cholera by almost half
Explain why we have no adaptive immunity against gonorrhea. Why are people with gonorrhea more likely to get infected with other sexually transmitted pathogens?
Helper T-cells are not getting activated because of opa- proteins These opa proteins make us vulnerable to other STDS ( lecture time: 49:00)
What is the transmission route for Vibrio cholerae?
Humans through the fecal-oral route; contaminated food/water.
Superantigen (1)
Pryogenic toxin
Circle one from each pair: The lower respiratory tract has a diverse / sparse resident microbial community. Infections in the lower respiratory tract are common / rare and mild / severe.
Sparse Rare Severe
A bacteria isolated from an infected catheter of a patient is a Gram positive cocci in clusters seen on Gram stain. When grown in the lab, the bacterium is catalase positive and coagulase negative. What is the most likely pathogen causing this infection?
Staphylococcus epidermidis
Virulence factors associated with streptococcus pneumoniae (2)
capsule and alpha hemolytic
The M protein of Streptococcus pyogenes is strongly antigenic. A) Given this information, what type of vaccine (inactivated, live attenuated, subunit, toxoid) would seem to be well-suited for Strep. pyogenes?
subunit
You grow a bacterium from the blood of a patient that has vegetations (bacterial growths) on their aortic valve. The bacteria, when grown on a blood agar plate, are catalase negative, alpha-hemolytic, and stain as Gram positive cocci in chains. Based on the laboratory data, which microorganism is the most likely pathogen? (after L21)
(alpha-hemolytic) Streptococcus
List the causative agents and morphology (shape & arrangement, if applicable) of each of the following diseases. 1 Chlamydia 2 Gonorrhea 3 Syphilis
1 Chlamydia trachomatis, small cocci 2 Neisseria gonorrhoeae, diplococcus G- 3 Treponema pallidum, spirochete (unusual cell wall structure so PCN cannot get through) G-
Match the types of tuberculosis (latent, active) with their characteristics. 1 patient is not infectious 2 bacilli are contained by immune system 3 productive cough generates sputum 4 patient is contagious
1 Latent 2 latent 3 Active 4 Active
Instead of memorizing facts separately for each pathogen, try to look for patterns and exceptions. Identify the bacteria associated with each of the following statements. 1. This is the only bacteria in L20 that was an extracellular pathogen Lyme disease 2. This is the only bacteria in L20 that was not transmitted by an insect vector Anthrax 3. This is the only bacteria in L20 that had a non-living reservoir Anthrax - Bacillus Anthracis, (soil) • Which (one) bacteria in L20 had direct human-to-human transmission? Specify the type of disease associated with this transmission.
1 Lyme disease- Borrelia Burgdorferi 2 Anthrax - Bacillus Anthracis 3 Anthrax - Bacillus Anthracis, (soil) 4 Lyme disease- Borrelia Burgdorferi J) plaque *(rarely - untreated mother to fetus)
Predict the result of a tuberculin skin test (+ or -) for each of the following: BIOL 212, FA22 Homework 4 1 A person infected with TB 1 week ago (primary infection) 2 A person infected with TB 6 weeks ago (primary infection) 3 A person infected with TB 6 months ago (latent TB) 4 A person infected with TB 40 years ago (latent TB) 5 A person with active TB 6 A nurse who works with TB patients 7 A person who has had a TB vaccine 8 A person with AIDS and active TB
1 Negative 2 Negative 3 Positive 4 Positive 5 Postive 6 Positive 7 Positive 8 Positive
Dental caries occurs when sugars diffuse through plaque to _________________________ (name of bacteria), which in turn ferment the sugars into _______________ , which cannot diffuse out of the area, resulting in a gradual ___________________ of the enamel.
1 the embedded bacteria, streptococcus mutans which are attached to biofilm 2 Lactic Acid 3 Degradation
Gram reaction 1) Staphylococcus aureus 2) Streptococcus pyogenes 3)Streptococcus pneumoniae
1) + positive 2) + positive 3) + positive
List two laboratory diagnostic tests that could be used to differentiate Staphylococcus from Streptococcus.
1) Catalase test a) Staphylococcus - positive b) Streptococcus -Negative (microaerobic, does not want O2 around) *Catalase - Take glob of bacteria & put on a slide, add drop of hydrogen peroxide. If bacteria has catalase it will break HP down and bubble (positive)
Antibiotic Resistance? 1) Staphylococcus aureus 2) Streptococcus pyogenes 3)Streptococcus pneumoniae
1) Resistant to high salt, and chemical antimicrobial agents 2) in some species 3) Some resistant strains are emerging
Hardiness outside of host? 1) Staphylococcus aureus 2) Streptococcus pyogenes 3)Streptococcus pneumoniae
1) Tough 2) Delicate 3) Delicate; does not survive for long
Morphology and arrangement of: 1) Staphylococcus aureus 2) Streptococcus pyogenes 3)Streptococcus pneumoniae
1)Clusters of cocci 2)Chain of cocci 3)Diplococci
Based on the information in this article, how many people (globally) have Latent TB?
2 Billion people are infected with latent TB
What is the incidence of TB in 2006, expressed per 100,000 people? NOTE: the world's population in 2006 (which is when the data used in this article came from) was 6.7 billion.
2 bil/ 6.7 bil = 0.2985 x 100,000 = 29,851 per 100,000
List two laboratory diagnostic tests that could be used to differentiate Staphylococcus from Streptococcus.
2) MSA Plate a) Staphylococcus - Positive (resistant to high salt envo.) b) Streptococcus - Negative (delicate) *MSA plate - Grow bacteria on Agar MSA, If you are a bacteria that can handle salty env. you can grow.
How long is the "short course" anti-TB therapy?
6 Months
In 1882, when Mycobacterium tuberculosis was discovered, tuberculosis (TB) caused the deaths of one in every __________ people
7
Plaque on teeth is an example of which of the following? A Biofilm B Cavity C An infection D Dental caries
A Biofilm
A unique symptom of Lyme disease which is seen in 80% of cases is: A Bulls-eye rash at site of tick bite B Arthritis C Alzheimers symptoms D Fever and flu-like symptoms (these are all symptoms!)
A Bulls-eye rash at site of tick bite
Which of the following is/are a characteristic of Bacillus anthracis? Select all that apply A It is gram positive B It forms endospores C Found in soil D Produces endotoxins
A It is gram positive B It forms endospores C Found in soil *(Produces exotoxins!)
At what stage(s) is syphilis most easily spread? Select all that apply. A Primary syphilis (goes unnoticed) B Secondary syphilis Most contagious C Tertiary syphilis not contagious D Second latency less contagious
A Primary syphilis (goes unnoticed) B Secondary syphilis Most contagious
Which of the following lacks normal microflora? A Stomach B Mouth C Small intestine D Large intestine
A Stomach
How does Staphylococcus aureus cause gastrointestinal symptoms? A) By producing enterotoxins when growing in food B) By producing neurotoxins that are released into the food C) By reproducing in the intestines, causing enteritis D) By reproducing in the stomach, causing gastritis and ulcers
A) By producing enterotoxins when growing in food
List the causative agent and morphology (shape & arrangement) for each of the following diseases: 1 Rocky Mountain spotted fever 2 Lyme Disease 3 Plague 4 Anthrax
A) Causative Agent 1 Rickettsia 2 Borrelia Burgdorferi 3 Yersinia Pestis 4 Bacillus Anthracis
A persistent difficulty related to controlling the spread of gonorrhea is: A) The frequent emergence of antibiotic resistance B) Lack of adequate diagnostic tests C) Its transmission via aerosol droplets D) Increased needle sharing among IV drug users E) All of these
A) The frequent emergence of antibiotic resistance
The authors explain that combination therapy is used to combat different populations of bacilli. What is meant by "different populations of bacilli" in this context? A) There are several different subpopulations of M. tuberculosis that exhibit different growth rates B) The infection is mixed; both M. tuberculosis and other species of secondary infectious bacilli are in the lungs C) The bacteria exist in discrete populations in different parts of the lungs (e.g., some in the bronchi, others in the alveoli)
A) There are several different subpopulations of M. tuberculosis that exhibit different growth rates
How do asymptomatic Staphylococcus carriers (like hospital personnel) spread this bacterium? Select all that apply A) Via the skin B) By nasal droplets C) Fomites
A) Via the skin B) By nasal droplets C) Fomites
Select all THREE features that apply to pulmonary anthrax. A) caused by a spore-forming bacteria. B) a candidate for use as a bioterrorism agent (can be sent thru mail) C) bacteria secrete lethal exotoxins. D) has a lower fatality rate than cutaneous anthrax. E) reservoir are woodland mammals such as squirrels F) portal of entry is a tick or flea bite ( E, is wrong because reservoirs are livestock animals)
A) caused by a spore-forming bacteria. B) a candidate for use as a bioterrorism agent (can be sent thru mail) C) bacteria secrete lethal exotoxins. *( E, is wrong because reservoirs are livestock animals)
Which of the following bacterial STIs are sometimes asymptomatic? (Select all that apply) A) chlamydia B) gonorrhea C) syphilis (during early stages)
A) chlamydia B) gonorrhea C) syphilis (during early stages)
The lower respiratory tract is protected from infection by all of the following EXCEPT A) competition with the resident microflora of the lungs B) mucociliary escalator C) alveolar macrophages
A) competition with the resident microflora of the lungs
The upper respiratory tract consists of which of the following? Select all that apply. A) pharynx B) nasal cavity C) bronchi D) alveoli
A) pharynx B) nasal cavity
Women are more likely to develop cystitis than men because? A) the female urethra is shorter than the male urethra. B) urine in the male bladder is more acidic. C) the male urethra has a layer of mucus that the female urethra lacks. D) the male urethra is shorter than the female urethra. E) the anus and the urethra opening are farther apart in the female.
A) the female urethra is shorter than the male urethra.
Which THREE bacterial species causes lower respiratory tract infections by replicating inside alveolar macrophages? A) Streptococcus pyogenes B) Mycoplasma pneumoniae C) Mycobacterium tuberculosis D) Legionella pneumophila
B, C, D
Hemolysins A) Lead to a gamma-hemolytic pattern on blood agar if they can lyse RBC B) Are a type of endotoxin C) Are a common mechanism for pathogenic bacteria to acquire iron D) Destroy cell walls of bacterial pathogens
C) Are a common mechanism for pathogenic bacteria to acquire iron *(Gamma-hemolytic Do not lyse RBC at all, is an exotoxin, destroy cells walls of RBC) **rbc high in hemoglobin which is rich in iron (limiting nutrient) bacteria needs free iron in order to reproduce
Two men were admitted into the hospital with necrotic lesions resembling pieces of coal on their hands. They apparently contracted the skin disease while working with animal skins imported from Africa. The men were treated with ciprofloxacin and they recovered completely thanks to the prompt intervention, except for the scars where the lesions were. Their living quarters had to be thoroughly decontaminated, though, in case there were more spores from the animal skins that remained in the house. What did the men have and what was the causative agent? A) Septicemia most likely caused by species of Gram positive bacteria B) Bubonic plague caused by Yersinia pestis C) Cutaneous anthrax caused by Bacillus anthracis D) Rocky Mountain spotted fever caused by Rickettsia
C) Cutaneous anthrax caused by Bacillus anthracis *(C- Endospores enter skin abrasions)
Which of the following statements about Group B Streptococcus is FALSE? A) It is found in healthy carriers B) It causes sepsis and pneumonia C) It causes strep throat D) It causes infections in newborn babies
C) It causes strep throat
Which of the following is true of the chancre observed during primary syphilis? Select all that apply A) It lasts throughout all stages of syphilis. (In primary stage and sometimes second) B) It is painful C) It is usually found on the face. D) It is a hard, painless, lesion
C) It is usually found on the face (maybe) D) It is a hard, painless, lesion
Why are smokers more susceptible to respiratory infections? A) Nicotine destroys lysozyme and other antibacterial enzymes in mucus B) Their cells secrete less mucus than non-smokers C) Nicotine paralyzes cilia D) Smoker's cough inhibits immune function
C) Nicotine paralyzes cilia
What physical characteristic of children makes them more likely to develop Otitis Media? A) Small ears B) Small nasal cavity C) Short Eustachian tubes D) More robust immune response
C) Short Eustachian tubes
Virulence factors that help bacteria escape/avoid phagocytosis (4)
Capsule M Protein G Protein Hemolysins
Virulence factors associated with streptococcus pyogenes (6)
Capsule M protein G protein Hemolysins Streptokinase Hyaulorinidase
Which sexually transmitted bacterial pathogen is NEVER susceptible to penicillin?
Chlamydia, no peptidoglycan
Virulence factors associated with staphylococcus aureus (7)
Coagulase, Staphylokinase, Hemolysins, Capsule Pyrogenic toxin Exfoliative Toxin Enterotoxins
Explain the association between V. cholerae and copepods.
Copepods play a major role in multiplication, survival, and transmission of cholera.
Lyme Disease A) is rarely transmitted from human to human. B) can result in arthritis-like swelling of the joints and brain swelling. C) is caused by a spirochete. D) All of these answers are correct. (Explanation for (A): mother to fetus if it goes untreated)
D) All of these answers are correct. *(Explanation for (A): mother to fetus if it goes untreated)
The most common reservoir for Salmonella that cause enteritis is A) beef B) birds C) humans only D) soil E) poultry and dairy products
E) Poultry and Dairy Products *(Humans are also reservoirs!!)
Match each of the antibiotics in the anti-TB drug cocktail with their mechanism of action. You may have to refer to your lecture notes, OpenStax, or other sources Antibiotics 1 Rifampin 2 Isoniazid 3 Pyrazinamide 4 Ethambutol
Mechanism of Action 1) inhibits transcription 2)inhibits mycolic acid synthesis 3)causes accumulation of intracellular pyrazinoic acid (inhibits enzyme invovled in metabolism) 4) inhibits proper peptidoglycan formation
Based on what you learned about gonorrhea, what are 2 reasons why scientists have not been able to develop a gonorrhea vaccine?
Most strains of gonorrhea are multidrug resistant. Is resistant to penicillin since it produces beta-lactamase. Resistant to tetracycline. Gonorrhea constantly changes its own antigens and are multiple strains. Memory cells will not recognize it and must start off with primary cells again. Opa proteins bind to Helper T cells and prevent activation. Gonorrhea has high antigenic variability.
Why are villages in Bangladesh at high risk of cholera outbreaks during September and October?
Phytoplankton blooms, pathogenic microorganisms, occur the heaviest in september and october which in turn is followed by cholera outbreaks (in water supply)
Describe TWO reasons why syphilis can be challenging to diagnose
Symptoms are highly variable and it is difficult to stain and ID, therefore the only reliable method is to do an antibody test.
In your own words, briefly describe two reasons why TB is re-surging on a global scale.
TB is re-surging on a global scale due to lack of proper hygiene and limited access to health care for a lot of people
During the lecture, I listed three routes that systemic diseases could cause mortality. Which of these routes best describes how Bubonic Plague can cause death? A) The bacteria cause septicemia, which leads to septic shock and organ failure. B) The bacteria use the blood to travel to vital organs. Damage to the vital organs causes death. C) The bacteria secrete a toxin that either causes toxic shock or directly damages cells and tissues. (From notes: sepsis/ septic shock + toxins )
The bacteria secrete a toxin that either causes toxic shock or directly damages cells and tissues *(From notes: sepsis/ septic shock + toxins )
Treponema pallidum infections are systemic, as the bacteria can migrate to any tissue it likes. Yet, the predominant method of transmission is through sexual encounters. Why does Treponema usually require a sexual encounter to be transmitted?
The reason for this is because Treponema pallidum cannot survive outside the environment of mucous membranes in the body as well as it has to have an open lesion or sore to be able to contact it. J) It requires direct contact in order for it to be transmitted. The direct contact has to be from a broken chancre to spread. In addition, once it spreads to other body tissues and organs it is less contagious.
Match each bacterium with the corresponding statement. A) Strep. pneumoniae B) Klebsiella C) Legionella D) Mycoplasma E) Pseudomonas
_____A____ Which bacteria is the most common cause of bacterial pneumonia? ______E___ Which bacteria is an opportunistic pathogen commonly found on non-living surfaces, and can cause ear infections and pneumonia? _____B____ Which bacteria primarily infects immunocompromised patients, and causes severe damage to the lung, resulting in higher mortality? ______D___ Which bacteria causes walking pneumonia? ____C_____ Infections with this bacterium occur when people inhale aerosolized water droplets from a contaminated water source, for example air conditioning cooling towers.
