Đang tải... (xem toàn văn)
After studying this chapter you will be able to: Explain the medical assistant’s role in microbiology, describe how microorganisms cause disease, describe how microorganisms are classified and named, discuss the role of viruses in human disease, discuss the symptoms of HIVAIDS and hepatitis, discuss the role of bacteria in human disease,…
CHAPTER 46 Microbiology and Disease © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-2 Learning Outcomes 46.1 Explain the medical assistant’s role in microbiology 46.2 Describe how microorganisms cause disease 46.3 Describe how microorganisms are classified and named 46.4 Discuss the role of viruses in human disease 46.5 Discuss the symptoms of HIV/AIDS and hepatitis 46.6 Discuss the role of bacteria in human disease © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-3 Learning Outcomes (cont.) 46.7 Discuss the role of protozoa in human disease 46.8 Discuss the role of fungi in human disease 46.9 Discuss the role of multicellular parasites in human disease 46.10 Describe the process involved in diagnosing an infection 46.11 Identify general guidelines for obtaining specimens © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-4 Learning Outcomes (cont.) 46.12 Carry out the procedure for transporting specimens to outside laboratories 46.13 Describe two techniques used in the direct examination of culture specimens 46.14 Carry out the procedure for preparing and examining stained specimens 46.15 Carry out the procedure for culturing specimens in the medical office 46.16 Describe how to perform an antimicrobial sensitivity determination © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-5 Introduction • Microorganisms • Medical assistant – Everywhere in the environment – Identification of microorganisms – Cause disease if – Proper collection techniques • Pathogenic in nature • Displaced from their natural environment – Testing procedures – Quality control © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part Microbiology and the Role of the Medical Assistant 46-6 • Microbiology – study of microorganisms • Microorganisms – Resident normal flora – Pathogens • Medical assistant – Assist the physician – Preparing specimens © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-7 Apply Your Knowledge What role does the medical assistant play in relation to microbiology? ANSWER: The medical assistant may assist the physician in obtaining specimens, obtain specimens herself, prepare specimens for direct examination or transport to a reference laboratory, and possibly perform microbiologic procedures © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-8 How Microorganisms Cause Disease • Extensive variety of pathogens • People normally are able to avoid infection • Cause disease in variety of ways • May remain localized or become systemic • Transmitted directly or indirectly © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part Classification and Naming of Microorganisms 46-9 • Classification by structure – Subcellular – Prokaryotic – Eukaryotic • Standardized naming – Genus ~ biologic classification – Species of organism ~ distinct type of microorganism © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-10 Classification and Naming of Microorganisms (cont.) • Standardized naming – Genus • Category of biologic classification • Example – Staphylococcus – Species of organism • Represents a distinct type of microorganisms • Examples – Staphylococcus aureus and Staphylococcus epidermidis © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-49 Culturing Specimens in the Medical Office • Place a sample of specimen on a culture medium – Medium ~ nutrients – Place in incubator for growth – A colony develops as microorganism multiplies © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-50 Culture Media • Liquid, semisolid, or solid containing agar • Types – Selective – Nonselective • Special culture units © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-51 Inoculating a Culture Plate • Transfer some of the specimen onto a culture plate • Label the plate correctly • Qualitative analysis – determination of type of pathogen • Quantitative analysis – number of bacteria present in sample © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-52 Inoculating a Culture Plate (cont.) • Qualitative • Quantitative © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-53 Culturing Specimens (cont.) • Incubating culture plates • Interpreting cultures – Characteristics of colonies – Relative number – Changes to media around colonies © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-54 Determining Antimicrobial Sensitivity • Appropriate antimicrobial • An outside lab reports – Sensitive – Intermediate – Resistant • Inoculate and place antimicrobial discs • Incubate and evaluate © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-55 Apply Your Knowledge What is the process for culturing a specimen? ANSWER: Selective culture media allows the growth of only certain kinds of bacteria Unselective culture media support the growth of most organisms The office received a culture sensitivity report on a bacteria that said it was resistant to an antimicrobial What does this mean? ANSWER: It means that the bacteria was not killed by the antimicrobial and that there was an overgrowth of the bacteria © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-56 In Summary 46.1 As an office medical assistant, you may assist the physician with several microbiologic procedures that aid in diagnosing and treating infectious diseases 46.2 Microorganisms can cause disease by using up nutrients or other materials needed by the cells and tissues they invade, damaging body cells, and producing toxins 46.3 Microorganisms are classified on the basis of their structure Specific microorganisms are named in a standard way © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-57 In Summary (cont.) 46.4 Viruses are among the smallest known infectious agents causing common diseases, including the common cold, influenza, chickenpox, croup, hepatitis, and warts 46.5 The initial symptoms of AIDS are usually severe flulike symptoms followed later by systemic, respiratory oral, gastrointestinal, nervous system, and skin complaints The general symptoms of hepatitis include jaundice, diminished appetite, fatigue, nausea, vomiting, joint pain or tenderness, stomach pain, and general malaise © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-58 In Summary (cont.) 46.6 Bacteria are single-celled prokaryotic organisms that reproduce very quickly 46.7 Protozoans are single-celled eukaryotic organisms found in soil and water 46.8 Fungi are eukaryotic organisms including molds and yeasts 46.9 Multicellular parasites include roundworms, tapeworms, flatworms, ticks, lice, and mites © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-59 In Summary (cont.) 46.10 The steps involved in diagnosing an infection are to: examine the patient; obtain one or more specimens; examine the specimen directly either by wet mount or smear; culture the specimen; and determine the culture’s antibiotic sensitivity 46.11 The general guidelines for obtaining specimens are to: – obtain the specimen with great care to avoid causing the patient harm, discomfort, or undue embarrassment; – collect the material from a site; – obtain the specimen at the proper time; – use appropriate collection devices; – obtain a sufficient quantity of the specimen; and – obtain the specimen before antimicrobial therapy begins © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-60 In Summary (cont.) 46.12 When transporting specimens to outside laboratories, the medical assistant should: – Follow proper collection techniques using specific containers provided by the laboratory; – Maintain the samples in a state as close to their original as possible; and – Protect anyone who handles a specimen container from exposure to potentially infectious material 46.13 Direct examination of culture specimens is accomplished in two ways: wet mounts and KOH mounts © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-61 In Summary (cont.) 46.14 To prepare a stained specimen, the medical assistant must first prepare a smear, fix the sample to the slide so it does not wash off during the staining process, and follow a specific staining procedure 46.15 To culture a specimen, the medical assistant should place a sample of the specimen on or in a specialized culture medium and allow it to grow in an incubator for 24 to 48 hours © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-62 In Summary (cont.) 46.16 Performing an antimicrobial sensitivity test involves taking a sample of the isolated pathogen, suspending it in a small amount of liquid medium, and streaking it evenly on the surface of a culture plate Small disks of filter paper containing various antimicrobial agents are placed on top of the inoculated agar plate The plate is then incubated at 37º C, and the results are evaluated the following day © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part 46-63 End of Chapter 46 Each organism's environment, for the most part, consists of other organisms ~ Kevin Kelly © 2014 by McGraw-Hill Education This is proprietary material solely for authorized instructor use Not authorized for sale or distribution in any manner This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part .. .46- 2 Learning Outcomes 46. 1 Explain the medical assistant’s role in microbiology 46. 2 Describe how microorganisms cause disease 46. 3 Describe how microorganisms are classified and named 46. 4... 46- 3 Learning Outcomes (cont.) 46. 7 Discuss the role of protozoa in human disease 46. 8 Discuss the role of fungi in human disease 46. 9 Discuss the role of multicellular parasites in human disease. .. website, in whole or part Microbiology and the Role of the Medical Assistant 46- 6 • Microbiology – study of microorganisms • Microorganisms – Resident normal flora – Pathogens • Medical assistant –