2 Objectives: 46-1 Define microbiology. 46-2 Describe how microorganisms cause diseases. 46-3 Describe how microorganisms are classified and named. 46-4 Explain how viruses, bacteria, protozoans, fungi, and parasites differ and give examples of each. 46-5 Describe the process involved in diagnosing an infection. Introduction to Microbiology
3 Objectives (cont.) 46-6 List general guidelines for obtaining specimens. 46-7 Describe how throat cultures, urine, sputum, wound, and stool specimens are obtained. 46-8 Explain how to transport specimens to outside laboratories. 46-9 Describe two techniques used in the direct examination of cultures specimens. 46-10Explain how to prepare and examine stained specimens. Introduction to Microbiology
4 Objectives (cont.) 46-11Describe how to culture specimen in the medical office. 46-12 Explain how cultures are interpreted. 46-13 Describe how to perform an antimicrobial sensitivity determination. 46-14 Explain how to implement quality control measures in the microbiology laboratory. Introduction to Microbiology
5 Introduction When microorganisms are pathogenic in nature or displaced from their natural environment, they cause infections and disease. You will learn: Processes in identifying microorganisms Culture medias used Antimicrobial testing Quality control You must understand different life forms of microorganisms, how they may be identified, and how to teach proper collection techniques for common specimens.
6 Microbiology and the Role of the Medical Assistant Microbiology – study of microorganisms (simple forms of life visible only through a microscope usually single celled) Found everywhere Cause infections Mild Severe
7 How Microorganisms Cause Disease By using up nutrients or other materials needed by cells and tissues they invade By damaging body cells by reproducing inside the cells By making body cells targets of bodys own defenses Resulting in: Fever Tiredness Aches Weakness Skin reactions Gastrointestinal upset Transmitted from one person to another by direct touching or by vectors, droplets, or contaminated food or drink.
8 Classifications of Microorganisms Classifications: Subcellular – DNA or RNA surrounded by a protein coat Prokaryotic – simple cell structure no nucleus or organelles Eukaryotic – complex cell structure with nucleus and specialized organelles
9 Naming of Microorganisms Types of microorganisms: Viruses Bacteria Protozoans Fungi Multicellular parasites Named by first word refers to genus (biologic classification between family and species) and second word refers to particular species Staphylococcus aureus
10 Viruses Smallest known infectious agents Cannot be seen by regular microscope Consist of only nucleic acid surrounded by a protein coat Causes: Colds Influenza Croup Hepatitis Hepatitis Virus
11 Bacteria Single-celled prokaryotic organisms Reproduce quickly Major cause of diseases Many different types and ways to identify them Rapid reproduction is why untreated infections can be dangerous Bacillus bacterial classification
12 Bacteria Classification Shape – coccus, bacillus, spirillum, virbrio Ability to retain certain dyes Ability to grow in presence or absence of air Biochemical reactions Spirillum bacterial classification
13 Protozoans Single celled eukaryotic organisms – larger than bacteria Found in soil and water Cause: Malaria Amebic dysentery Trichomonus vaginalis Protozoan Trichomonus vaginalis
14 Fungi An eukaryotic organism – rigid cell wall Grow mainly as single-celled Reduce by budding Yeasts Molds Cause superficial infections Athletes foot Ringworm Thrush Yeast a single- celled fungi
15 Parasites Organism that lives on or in another and uses that organism to provide nourishment Infections caused by parasites are called infestations Worms Insects -ticks
16 Apply Your Knowledge How is bacteria classified? Shape – coccus, bacillus, spirillum, virbrio Ability to retain certain dyes Ability to grow in presence or absence of air Biochemical reactions Answer -Answer
17 Diagnosing Infections Step 1 – Examine the patients signs and symptoms Step 2 – Obtain Specimens Step 3 – Examine the Specimens Directly Step 4 – Culture the Specimen Step 5 – Determine the Cultures Antibiotic Sensitivity Step 6 – Treat the Patient as Ordered
18 Specimen Collection If specimen is collected incorrectly, the organism will not grow in culture and then cannot be identified. If a specimen contains contaminants that are identified as causing the infection, the patient may be treated incorrectly.
19 Specimen Collection Devices Sterile swabs Absorbent material on the tip Collection and transporting systems Contains a polyester swab and a small thin-walled vial of medium in a plastic sleeve
20 Throat Culture Specimens Avoid touching any structures in the mouth Get the specimen from the throat area only Clinical medical assistants must know how to obtain a throat culture specimen correctly
21 Other Specimens Urine Obtain clean-catch midstream specimen to prevent contaminants Sputum Instruct patient to cough up mucus from the lungs Wound Use a swab Stool Use clean paper plate or waxed paper
22 Transporting Specimens Many offices do not perform microbiologic testing. You may send culture specimens to outside labs. There are three main objectives.
23 Transporting Specimens (cont.) Three main objectives: 1.Follow proper collection procedures and use correct device. 2.Maintain the samples in a state close to their original as possible. 3.Protect anyone who handles the specimen container from exposure to potentially infectious material.
24 Methods of Transportation Regularly scheduled daily pickups by the lab As needed pickup by the lab Through the mail
25 Direct Examination of Specimens Physician may examine specimens under the microscope to detect microorganisms. Two types of procedures: Wet mounts- permits quick identification Potassium Hydroxide (KOH) mounts – suspects a fungal infection of the skin, nails, or hair.
26 Stained Specimens Enables the doctor to differentiate between types of infections. The medical assistant should be able to prepare a specimen slide and perform a Grams stain.
27 Culturing Specimens You will need on-the-job training or additional courses to culture certain specimens. More common to send these specimens to outside labs. Culturing involves placing a sample of specimen on a culture medium.
28 Culturing Specimens (cont.) Culture media – liquid, semisolid, or solid forms Medium called – agar Special culture units – used to perform rapid urine cultures (Unicult)
29 Culturing Specimens (cont.) Inoculating a culture plate Transferring some of the specimen onto the plate Label the plate: Patients name Doctors name Source of sample Date and time of inoculation Your initials
30 Culturing Specimens (cont.) Streak the plate with the specimen swab for: Qualitative analysis – type of pathogen Quantitative analysis – number of pathogen present in the specimen Incubating Culture plates – to allow bacteria to grow (incubator set at 35 to 37 0 C) Allow to grow for 24 to 48 hours.
31 Interpreting Cultures This step is performed by physicians, microbiologists, or technicians who have been properly trained. They will look for: Characteristics of colony growth Relative number of colony growth Changes in the media surrounding the colonies
32 Determining Antimicrobial Sensitivity Taking a sample of the isolated pathogen and suspending it in a liquid medium and streaking it on a culture plate. Small disks of filter paper with antimicrobial agents are placed on top. Plate is incubated at 37 0 C for 24 hours. The antimicrobial that inhibited microbial growth will be effective in treating the infection.
33 Quality Control in the Office Ongoing system to evaluate the quality of medical care being provided. Provides an objective means to define, monitor, and correct potential problems. All media, staining solutions, and reagents should be evaluated frequently. Equipment must also be in proper running order.
34 Impact of CLIA 88 All labs must incorporate the appropriate policies and procedures to comply with CLIA 88 Proper documentation of lab policies and procedures, materials, and lab personnel qualification and training. Proficiency testing program monitors quality of laboratorys test results
35 Apply Your Knowledge How are pathogens tested to see if they can be treated effectively by antimicrobial agents? Small disks of filter paper with antimicrobial agents are placed on top of the inoculated culture plate, and if the antimicrobial agents stop the growth of the pathogens, it will be effective in treatment of the infection. Answer -Answer
36 Summary Medical Assistant Developing your clinical skills will be an asset to the office and will allow you to advance your career. Quality control in the microbiology laboratory is an important factor in ensuring high-quality medical care.