Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Assisting in Microbiology and Immunology Chapter 54
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 2 Microbiology The medical assistant needs to understand the role of microorganisms. The main objective of microbiology procedures is to identify the organisms responsible for illness so that the physician can properly treat the patient. Microbiology procedures may be performed in the POL or in the microbiology department of a medical referral laboratory.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 3 Specimen Collection and Transport “In what ways can I prevent extraneous microorganisms from contaminating this sample?” “What can I do to prevent myself from becoming infected while I collect this sample?”
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 4 Specimen Collection and Transport Transport media – Stuart medium or Amies medium The medical assistant must strictly follow the directions. Transport specimen directly after collection or by courier.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 5 Containers for Transport
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 6 Collection Devices
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 7 Classification of Microorganisms Bacteria, fungi, protozoa Parasitic worms Viruses
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 8 Naming of Microorganisms Binomial system of nomenclature – Assigns two names: the first is the genus, and the second is the species – Neisseria gonorrhoeae
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 9 Typical Pathogenic Bacteria Bacteria are single-celled prokaryote organisms that reproduce by binary fission. Often classified by their shape, staining characteristics, and the environmental conditions. Three types of cell wall structures: gram positive, gram negative, acid fast.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 10 Bacterial Shapes
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 11 Bacterial Oxygen Requirements Aerobes Anaerobes Facultative anaerobes
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 12 Bacterial Physical Structures Flagella Capsules Endospores
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 13 Unusual Pathogenic Bacteria Chlamydia Mycoplasmic Rickettsiae
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 14 Fungi Mycology Fungi are eukaryotes, larger than bacteria Present in soil, air, and water Few cause disease Transmission
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 15 Parasites Parasitology Transmitted by ingestion during the infective stage, direct penetration of the skin, inoculation by a vector Identified in urine, sputum, or tissue fluid or through tissue biopsy Helminths Protozoa
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 16 Parasites
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 17 The Microbiology Laboratory Most laboratories have: – Refrigerator, autoclave, safety cabinet, microscope, and incubator
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 18 Inoculating Equipment Inoculating loops and needles
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 19 Incineration Equipment Fastest way to sterilize reusable equipment Used to heat-fix smears Bunsen burner
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 20 Incineration Equipment (cont’d)
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 21 Culture Media Solid, liquid, or semisolid
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 22 Inoculation of Media Quadrant streak Lawn or spread streak After inoculation, plate is inverted
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 23 Identification of Pathogens in the Microbiology Laboratory Assessing a culture – Throat culture – Urine culture Staining – Gram’s stain – Acid-fast stain
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 24 Identification of Pathogens in the Microbiology Laboratory (cont’d)
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 25 Identification of Pathogens in the Microbiology Laboratory Gram stain
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 26 Identification of Pathogens in the Microbiology Laboratory Biochemical testing – Performed to identify the genus and species Rapid identification methods – Designed to give the physician a positive indication of the problem – Rapid strep testing – Influenza A and B testing – RSV testing
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 27 Identification of Pathogens in the Microbiology Laboratory (cont’d)
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 28 Antimicrobial Susceptibility Testing “Culture and sensitivity” test. The physician’s decision for antimicrobial agents is based on numerous factors. – Test results, physical examination, and the knowledge of the patient Kirby-Bauer Antimicrobial Susceptibility Test.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 29 Antimicrobial Susceptibility Testing (cont’d)
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 30 Miscellaneous Microbiology Testing Testing for pinworms – Specimens best collected at night or early before bowel movement, urination, or bathing. – Petroleum jelly paraffin swabs used to collect eggs. – Parent may also be instructed to bring child to office.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 31 Immunology Testing Provides information about past or present infections with bacteria or viruses and certain cancers Demonstrates the reaction between antigen and antibody – Agglutination, precipitation, immunochromatographic assay
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 32 Immunology Testing The medical assistant may perform CLIA-waived tests for infectious mononucleosis, H. pylori, HIV, and Lyme disease.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 33 Patient Education List of teaching topics to help educate patients – An explanation of patient’s type of infection – How infection spreads – Normal barriers to infection – Risk factor – Patient preparations, collection – Hand washing, proper storage and cleaning