quiz 3 micro2420

Examine the status of MRSA infections in the United States today by completing each sentence. Then, arrange the sentences in a logical sequence.

*MRSA* stands for *methicillin*-resistant Staphylococcus aureus, even though these strains are usually resistant to multiple antibiotics. Because of its resistance, MRSA is classified as a *serious* threat in the CDC Antibiotic Resistance Report. S. aureus is a common and hardy contaminant on surfaces, and it can cause bloodstream infections in hospitalized patients, known as *healthcare-associated* MRSA. In 2004, MRSA infections began to appear in individuals with no history of hospitalization; these were classified as *community-associated* MRSA. CA-MRSA is more common in *younger* populations, and its incidence is *increasing*.

Features of Immunological Testing Examine the basis of several serological tests by completing each sentence.

*Serology* is a branch of immunology that traditionally deals with in vitro diagnostic testing of serum. *Sensitivity*, or the ability to detect even minute amounts of target antibodies or antigens, is an important characteristic of such in vitro tests, as is *specificity*, or the test's ability to eliminate reactions with unrelated or distantly related antigens. *Agglutination* tests, such as the *Weil-Felix reaction* test for rickettsial infections, are an example of accurate in vitro serological tests, which produce antibody-mediated cell clumping that can be visualized for positive identification of a microbial infection. In contrast, *precipitation* reactions produce insoluble antibody-antigen complexes in vitro that can be visualized for positive identification of a microbial infection.

Impetigo Select all of the statements that apply to the pathological aspects of impetigo, a skin disease.

- Staphylococcus aureus and Streptococcus pyogenes are the causative organisms. - The most common modes of transmission are direct and indirect contact.

What's the Diagnosis? Pathogen Identification Endospore staining was performed on a microbial culture from the lesion (see results below). In accordance with established guidelines, patient specimens were sent out to the CDC for PCR testing to confirm the patient's diagnosis. It was negative for any viral, fungal, or protozoan pathogens, but was positive for a gram-positive bacterium.

1. Based upon all of the information obtained through specimen testing, along with the patient's symptoms, the pathogen is most likely _______. -Bacillus anthracis 2. Based upon this identification, what was the most likely mode of transmission of this pathogen? -Direct contact with endospores 3. Based upon this diagnosis, what disease is the patient suffering from? -Cutaneous anthrax.

Sepsis Data Analysis

1. Based upon this data, at which time point could the infected patient expect to obtain a false-negative result on an ELISA HIV screening test? -1 week post-infection 2. Knowing that the screening tests cannot detect antibodies until they are present at a concentration of 20 micrograms/mL or more, which is the first time point the patient could be accurately tested? -4 weeks post-infection 3. Which of the following is an accurate description of the antibody response to HIV in this infected patient? -Antibody levels stabilize after 3 months into infection.

HIV Testing Please locate this article through an online search engine: Ham DC, Huang Y, Gvetadze R, Peters PJ, Hoover KW. Health Care Use and HIV Testing of Males Aged 15-39 Years in Physicians' Offices—United States, 2009-2012. MMWR Morb Mortal Wkly Rep 2016;65:619-622. DOI: http://dx.doi.org/10.15585/mmwr.mm6524a3. Read the article thoroughly, and then answer the questions below.

1. In 2014, the highest number of new HIV infection diagnoses was among what population? Males, age 20—29 2. In 2014, HIV incidence was highest in which racial/ethnic group? Black, non-Hispanic 3. Which statements best summarize HIV testing coverage in the United States as indicated by this report? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) -Because rates of health care visits are higher than testing rates, there is room for improvement in coverage at doctor's offices. -Opt-out testing and electronic reminders to physicians may improve testing rates. -Only about 1/3 of males over 18 years of age have ever been tested for HIV. 4. Black males are less likely to visit the doctor annually and less likely to be tested for HIV if they do visit the doctor. False 5. The CDC recommended routine HIV testing in 2006 in adults and adolescents. However, testing coverage is very low. Select some possible reasons for this. (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) -General practitioners may not assume responsibility for this intervention. -Physicians may not believe their patients are really at risk. -Testing recommendations are not known by public or medical professionals.

Agglutination and Precipitation Animation Please view this animation on agglutination and precipitation, and answer all questions to expand your knowledge.

1. In vitro tests are performed ________. -in a test tube and in cell culture 2. An agglutinate forms when ________. -soluble antibody reacts with insoluble particles 3. True or False: Hemagglutination occurs when certain viruses are mixed with lymphocytes. -False 4. True or False: The addition of measles-specific antibodies would not block hemagglutination from occurring when the measles virus is mixed with red blood cells. -False 5. Agglutination tests can be performed using serial dilutions of patient sera to determine ________. antibody titer 6. Precipitates can form when ________. -soluble antibody reacts with soluble particles 7. The zone of equivalence ________. -results in the greatest amount of precipitate formed

ELISA Concept Check #2

1. The ELISA test _______. uses enzymes and substrates 2. Place the following reactants in the proper order of their usage in the indirect ELISA test.1 = enzyme-linked antibody2 = known antigen3 = patient serum4 = substrate 2 3 1 4 3. What accounts for a color change in a direct ELISA? Binding between the second antibody and the substrate 4. An ELISA to detect the hCG hormone, elevated during pregnancy, would be classified as a(n) ________ ELISA. direct

ELISA View the following video that describes the ELISA procedure and answer the questions below.

1. The ELISA test can detect both antibodies and specific antigens. true 2. In direct elisa, what is added first to the microtiter well antibodies 3. What indicates the presence of the substance being tested for in the elisa test a color change 4. In indirect elisa, what is added first to the microtiter well antigen

NCLEX: Clinical Application (Lumbar Puncture for Meningitis) Concept Check

1. The RN provides education for the patient about the procedure. In her teaching, she states that the purpose of a lumbar puncture is to collect which type of body fluid? -Cerebrospinal fluid 2. The RN places the patient in which of the following positions for the procedure? -On her side with flexed neck and drawn knees or sitting upright with head and neck flexed forward 3. The patient verbalizes concern of the risk of paralysis from the procedure. Which of the following is the most appropriate response by the RN? -The puncture is done below the level of spinal cord termination 4. Following the procedure, all of the following are important interventions, except ________. -early ambulation

Agglutination and Precipitation Concept Check #1

1. The branch of medicine that tests a patient's serum for antibodies as indicators of infection is ________. serology 2. The basis for this type of diagnostic testing is ________. the specific binding of antigen to antibody 3. Which of the following is not a method used for visualizing the antigen-antibody reactions in diagnostic immunology? Bright-field microscopy

NCLEX: Clinical Application (Measles) Concept Check

1. The causative organism for measles is a ________. -Virus 2. Which of the following interactions is most likely to transmit the disease? -Sneezing 3. Which of the following is the most effective method of measles prevention? -Vaccination 4. Which of the following interventions would the RN expect to be utilized for treatment of this patient? -All of these would be interventions. 5. The RN provides education to the students at the college regarding measles symptoms. With a high index of suspicion for measles infection, all of the following presentations are likely contagious, except: -24-year-old male with no fever and resolving generalized rash

Sepsis Concept Check #2

1. The patient in this case was diagnosed with ________. septicemia 2. Why was the patient given antibiotics in this case? A bacterium was found in his blood 3. Which of the following is a correct pairing of a microbial identification test with its category type? D. Fermentation test—Phenotypic Method

Agglutination and Precipitation Concept Check #2

1. To determine antibody titer, you will need ________. -serial dilutions of the patient's serum 2. The antigens being tested for in precipitation reactions are ________. -soluble 3. The antigens being tested for in agglutination reactions are ________. -attached to whole cells

Measles (Analysis) Data Analysis You are a nurse with the World Health Organization. You are in charge of collecting data on worldwide vaccination rates and measles incidence reporting. You have recently collected the following data on cases of measles over the past 35 years. In addition, you have determined that vaccination rates have steadily climbed worldwide since 1980, and the current rate of adherence to measles vaccination worldwide is 85%. Read the graph, and answer all questions below.

1. True or False: Based upon the data, it appears that the measles vaccine should be taken off of the market as it is not effective. -False 2. You note that, for some unknown reason, in one year there was a significant reduction in the vaccination rate worldwide. Based upon the data, which year may this have been? -1980 3. Based on this data, which year exhibited the greatest reduction in the number of measles cases worldwide? -1984-1986

Sepsis concept check #1

1. True or False: In the case file, the patient's urine sample was obtained aseptically by the clean-catch method. -False 2. Specimen testing falls into one of three categories: ________, genotypic, or immunologic testing. -phenotypic 3. Why is it important to draw blood from two different sites for blood cultures? -All of these choices are correct.

NCLEX: Clinical Application (HIV Testing) Concept Check

1. What immunoassay test is utilized commonly as an initial antibody screening for HIV? ELISA 2. Which of the following tests is performed as verification for preliminary antibody-positive HIV screening tests? Western blotting 3. The second verification test for HIV is conducted on the patient's blood sample, and the test produced bands in the same area as the positive control. Based upon this information, what result would be reported to the patient? Positive test 4. Complement fixation tests and agglutination reactions represent which method of microbial identification? Immunologic

What's the Diagnosis? Identification of Drug Therapy

1. What was the most likely source of the endospores the patient came in contact with leading to infection? -Animals and animal hides 2. Which form of treatment should be administered to the patient at this time? -Levofloxacin 3. True or False: Vaccination could have prevented the development of this disease in the patient. -True

ELISA Concept Check #1

1. Which component of blood contains antibodies? Serum 2. ______ are molecules that stimulate a response by T cells and B cells Antigens 3. B lymphocytes _______ are activated by T helper cell interaction 4. Immunoassays are useful ______. all of these choices are correct.

Evaluate the case studies, and make your diagnoses based on the histories, manifestations, and test results.

A patient had unprotected sex two months ago, and has been experiencing flu-like symptoms within the past week. You order an indirect ELISA test which confirms that the individual has been infected with ____________ . -HIV You are about to start your clinical nursing rotations and have to go for some routine tests. You are injected with some purified protein derivative and within 72 hours you have a red, raised lesion at the site of the injection. This confirms you have been exposed to ____________ . -tuberculoses Your 13-year-old child received all routine vaccinations as an infant but has recently become very ill, having paroxysmal coughing with loud intakes of breath. The pediatrician took samples from the nose and throat that were subject to PCR analysis for rapid confirmation that your child has ____________ . -whooping cough You are a physician at an urgent care center. A patient comes in with a fever, severely swollen lymph nodes, white spots on the back of the tonsils, and difficulty swallowing. To save time, you do a rapid lateral flow immunochromatographic test which confirms your suspicion that the patient has ____________ . -strep throat

Detecting Whole Antigens What type of test will detect whole antigens?

Agglutination

Fifth Disease Fifth disease ________.

All of the choices are correct.

The lumbar puncture was especially uncomfortable for the patient. What step listed below is most important to be taken to ensure the procedure does not need to be repeated?

All of the choices are equally important.

NCLEX Prep - Question 1.1 The patient's CRP is markedly elevated. What does this indicate?

An elevated CRP points to inflammation from any of a variety of sources.

NCLEX Prep - Test Bank Scenario Question 2.4 The lesions are diagnosed as S. aureus impetigo. The nurse is educating the mother about why her daughter's affected skin seems so fragile and blisters easily. Which of the following statements is most appropriate?

An exotoxin produced by S. aureus targets a protein responsible for cell-to-cell binding, and blisters are the result.

Phenotypic Methods of Identification Which of the following is not a phenotypic method of identification?

Antibody response

NCLEX Prep - Test Bank Scenario Question 1.1 A mother brings her 7-year-old daughter to her pediatrician's office. It is written in the patient's chart that she is not immunized. The child has approximately 50 lesions, mainly concentrated on her trunk. Most of the lesions are vesicular, but a few have scabbed over. According to the mother, her daughter was previously healthy and developed this rash about five days ago. She denies any fevers and the rash appears to be persistently itchy. The RN observes the child itch open a vesicle, revealing a clear fluid. Based upon the patient's symptoms, the most likely diagnosis is ________.

Based upon the patient's symptoms, the most likely diagnosis is ________. chickenpox

Differentiation of Staphylococci What enzyme is not found in Staphylococcus epidermidis but is found in Staphylococcus aureus?

Coagulase

Diagnosing Infections Drag and drop the labels into the correct empty boxes to complete the concept map.

Direct and indirect are not correct in the picture they need to be swapped

Which of the following is not a genotypic method of identification?

Direct antigen testing

Test for Nonculturable Bacteria Which test is especially good for bacteria that are not readily cultivated in the lab?

Direct fluorescence antibody (DFA) testing

NCLEX Prep - Test Bank Scenario Question 1.3 The mother requests antibiotics to treat her daughter's infection. What is the most appropriate action by the RN?

Educate the mother that chickenpox does not respond to antibiotics, but is self-limiting and will heal on its own.

Complement Test Detection The complement fixation test looks for the presence of specific antigens in the patient's blood.

False

Immune Responses of the Eye Since the eye's primary function is vision, it is important to have a strong, easily initiated inflammatory response in this region.

False

Lysis of Blood Cells Lysis of sheep red blood cells indicates the patient has the antibody being tested for.

False

Cultivation of Specimens Match each statement with the correct isolation technique to test your understanding of how patient specimens are cultivated.

In the patient's specimen, the suspected pathogen is present in very small numbers. -enriched A patient's nonsterile fecal specimen contains an array of bacterial species in addition to the suspected pathogen. -selective A patient's specimen contains a suspected pathogen that will display a distinctive reaction with red blood cells. -differential

Bacterial Conjunctivitis Select all of the statements that apply to bacterial conjunctivitis.

It is caused by more than one type of bacteria. In children and adults, prevention is through good hygiene.

NCLEX Prep - Test Bank Scenario Question 1.4 The child shares a bedroom with her younger brother, who has not been vaccinated against or infected with chickenpox. He is supposed to go to summer camp in one week. The mother asks if it is safe to let him go to camp. How would the nurse best respond?

No, it is not safe for him to go. Since chickenpox has an incubation period of 10-20 days, he could begin exhibiting symptoms at camp.

Complement in the Blood Which is true? A patient positive for the disease will show an decrease in complement in his blood and thus give a positive test. All patients have equal amounts of complement in their serum. A patient positive for the disease will show an increase in complement in his blood and thus give a positive test. Patients differ in the amount of complement naturally found in their serum.

Patients differ in the amount of complement naturally found in their serum.

Categories of Diagnosis Which category of diagnosis is represented by studying a microbe's utilization of nutrients?

Phenotypic

Importance of Growth Conditions Which of the following diagnostic techniques is most likely to be affected by changes in growth conditions of the specimen?

Phenotypic

Sepsis Peptide Nucleic Acid FISH Test

Positive blood cultures can be tested for the specific identity of the blood-borne pathogen using the peptide nucleic acid FISH test. In the PNA FISH test, cultures are mixed with *probes* that have been labeled with a *fluorescent* molecule. These small pieces of DNA are *complementary* to rRNA sequences in a particular microorganism. If that organism is present in the cultured sample, this piece of DNA will *hybridize* to rRNA in the microbial cells. The culture can then be analyzed with a *microscope* to observe the presence of "glowing" cells. This is an example of a *genotypic* method of identification.

Use of Radioactive Isotopes Which test uses radioactive isotopes to label antibodies or antigens in order to detect minute amounts of corresponding antigen or antibody?

Radioimmunoassay (RIA)

Identifying Infectious Agents Which of the following is not one of the main categories for identifying microbes?

Radiologic

NCLEX Prep - Test Bank Scenario Question 1.2 A staff member in the office is concerned that the state health department needs to be notified of a suspected case of smallpox infection. The RN caring for the child discusses the distinct differences between the symptoms of chickenpox and smallpox. Which of the following is not true concerning the two diseases?

Smallpox lesions are filled with clear fluid, whereas chickenpox lesions are filled with a thick, opaque liquid and are distinctly indented in the center.

NCLEX Prep - Test Bank Scenario Question 2.2 In the lab, the specimen is Gram-stained and inoculated onto blood agar. Microscopic analysis of the slide reveals gram-positive cocci arranged in grapelike clusters, while the blood agar produces round, creamy colonies with clear areas of hemolysis. Which of the following would be the most likely causative organism?

Staphylococcus aureus

The indirect ELISA test is used to diagnose all of the following except ________.

Strep Throat

NCLEX Prep - Test Bank Scenario Question 2.1 The provider orders a specimen to be obtained for microbial analysis. What is the most appropriate site to culture in this case?

The lesion itself, since there seems to be a superficial infection

NCLEX Prep - Test Bank Scenario Question 2.3 The lab results indicate that the coagulase test was performed. Which result would be consistent with a diagnosis of S. aureus infection?

The sample completely coagulates

The patient's respiratory PCR results are reported as "insufficient cells available for testing." Which of the following statements by the student nurse indicates proper understanding of the findings?

The sample was inadequate, and the nasopharyngeal specimen collection must be repeated.

The patient's urine culture was collected using a clean-catch method. After inoculation and incubation, several organisms were identified in amounts that were reported as normal microbial flora. Which of the following statements by the student nurse indicates proper understanding of the findings?

This is a common finding due to contamination of a clean-catch urine sample with normal microbiota from the urogenital area.

Animal Inoculation Animals are required for the cultivation of ________.

Treponema pallidum

False Positive Tests When antibodies or other substances in serum cross-react with the test reagents, a false positive result can occur.

True

Infection and Human Gene Expression Bacterial infection causes the expression of different human genes than does viral infection.

True

Phenotypic Analysis Drawbacks If a phenotypic analysis requires culturing the organism before testing can begin, this is problematic for two reasons; i) rapid diagnosis may be critical and culturing can take up to 24 hours, and ii) a successful in vitro culturing method for a specific pathogen may not be feasible.

True

Presumptive and Confirmatory Data The analysis of infectious agents in laboratory specimens generates results that can fall into two categories: presumptive data and confirmatory data.

True

Types of MRSA Infections MRSA infections that occur in individuals who have had no recent history in hospitals or clinics are termed community-acquired or CA-MRSA cases.

True

Use of the Western Blot Test Western blotting is the second (verification) test for preliminary positive HIV screening tests because it can detect the presence of microbial-specific antigens or antibodies in a highly specific and sensitive manner.

True

Needle Aspirations Which sample is not typically collected by sterile needle aspiration?

Urine

Visualization of Results of Biochemical Testing Choose the phrase that best describes how most enzymatic reactions are observed in the biochemical testing of microbial specimens.

Usually visualized by a color change

Which test is the confirming test for people who initially tested antibody-positive in the screening ELISA test for HIV?

Western blot

Identification Using Biochemical Tests Microbes can be identified using automated biochemical tests, often without incubation. An example of this type of test would include ________.

a different pattern of bands

PFGE When using pulsed-field gel electrophoresis, mutations in a microbe's genome will show up as _______.

a different pattern of bands

Indirect ELISA A positive indirect ELISA result requires ________.

a known antigen, an unknown antibody, and a known antibody

First Step In the beginning of the complement fixation test, ________.

a patient's serum is heated to destroy complement and a measured amount of complement and antigen is added

Identification Using Biochemical Tests Microbes can be identified using automated biochemical tests, often without incubation. An example of this type of test would include ________.

a test for the presence of the enzyme urease, that would change the media from yellow to red

Viral Conjunctivitis Which is true of viral conjunctivitis?

caused by adenoviruses

Advantage of Genotypic Methods The primary advantage of genotypic methods of identification is ________.

culturing of the organism is not required

Serum Titers A serum titer involves ________.

determining the highest dilution of serum that produces a visible reaction

The Tuberculin Skin Test The tuberculin skin test is read ________.

from 48 to 72 hours

Skin Defenses Protective features of the skin include all but ________.

high pH

Detecting Biofilms Which of the following techniques is most likely to reveal that an infection is in biofilm form?

imaging

Characteristics of Smallpox Smallpox is a disease ________.

in which fever, prostration, rash, and possible toxemia and shock occur

Precipitation Tests In precipitation tests, the antigen ________.

is a soluble molecule

Skin Diseases Move the terms into the correct empty boxes to complete the concept map.

left side A. Necrotizing fasciitis B. Cellulitis C. Impetigo Right side Gas gangrene penicillin and clindamycin surgery oxygen therapy

Identifying Microbes The three main techniques for identifying microbes are ________.

phenotypic immunologic genotypic

Mass Spectrometry Mass spectrometry identifies microbes via _______.

protein fingerprints

Results of the Test In the complement fixation test, ________.

red blood cells settle to the bottom if the patient has antibody being tested for

Detecting Antibodies and Antigens The property of a test to detect even small amounts of antibodies or antigens that are test targets is ________.

sensitivity

Specificity vs. Sensitivity The ________ of a test means the test can detect even very small concentrations of the antigen or antibody being analyzed, whereas the ________ of a test focuses on the ability of a test to only detect the desired antigen or antibody without reacting with other unrelated substances.

sensitivity; specificity

False Positive Tests A test that results in a very large number of false positives probably has an unacceptable level of _______.

specificity

Interpretation of Serologic TB Test A positive serological test for tuberculosis indicates that ________.

the patient has been exposed to tuberculosis

In Vivo Testing In vivo testing is useful for diagnosing ________.

tuberculosis

Microbial Infections of the Skin and Eyes Label the image with the diseases (orange boxes) or causative agents listed for a review of microbial infections of the skin and eyes. Several pop-up hints have been provided to help you place the labels correctly.

wont let me find image use google other quizlets have it