Term
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Definition
Agents have no known potential for infecting healthy people |
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Term
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Definition
i. Most clinical labs fall into this category ii. Agents handled include all the common agents of infectious disease as well as HIV iii. Requires limited access and training of laboratory personnel iv. Hep B vaccine must be offered to all employees |
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Term
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Definition
i. Agents handled are unlikely to be handled in the routine clinical lab ii. Mycobacteria, mold stages of systemic fungi and other highly infectious agents iii. Special room and ventilation required as well as special protective clothing |
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Term
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Definition
i. Level 3 plus entrance through a separate room. Street clothing changed and replaced with laboratory clothing. All personnel and materials are decontaminated before leaving the area ii. Primarily research and public health facilities such as the CDC |
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Biosafety Cabinets Class I |
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Definition
allows room air to flow into the cabinet and around the area and material within |
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Biosafety Cabinets Class 2 |
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Definition
Sterilize both the air that flows over the infectious material and the air that is exhausted. Generally used in most hospital laboratories. |
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Term
Biosafety Cabinets Class 3 |
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Definition
Level II plus it is a closed system where rubber gloves are used in handling samples. There is no direct contact from outside the system. Generally used in Biosafety level 4 labs |
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Term
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Definition
The naming of microorganisms according to established rules and guidelines provides the accepted labels by which organisms are universally recognized. The genus and species of an organism are of most concern to microbiologists. |
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Term
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Definition
i) By convention the genus is always Capitalized and the species is not ii) Both are either underlined or italicized |
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Term
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Definition
relates to an organisms genetic makeup such as DNA or RNA |
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Term
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Definition
Macroscopic morphology – Growth patterns on artificial media ii) Microscopic morphology – Size, shape, appendages etc. iii) Staining characteristics – Ability of organism to stain a particular color iv) Environmental requirements – Temperature requirements v) Nutritional requirements – Carbon and nitrogen utilization patterns, carbohydrate fermentation vi) Antigenic properties – profiles by serologic methods vii) Subcellular properties – Cell wall and membrane components |
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Term
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Definition
i. Plural – Cocci meaning berries ii. Diplococci – pairs iii. Streptococci – chains iv. Tetrads – groups of 4 |
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Term
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Definition
i. Plural – bacilli meaning little staffs ii. Diplobacilli – pairs iii. Streptobacilli – chains iv. Coccobacilli – Bacilli that are oval and may appear more like Cocci |
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Term
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Definition
i. Vibrios – Bacteria that look like curved rods ii. Spirilla – helical or corkscrew shape and are rigid iii. Spirochetes – Helical or corkscrew shape and are flexible |
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Term
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Definition
o Staphylococcus o Streptococcus o Enterococcus |
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Definition
o Moraxella catarrhalis – diplococci o Neisseria gonorrhoeae – diplococci o Neisseria meningiditis - diplococci |
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Definition
o Bacteroides o Camplyobacter o Escherichia coli o Klebsiella o Salmonella o Shigella |
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Definition
o Actinomyces- branched o Bacillus- long wide, B. anthracis- “safety pins” o Clostridium o Corynebacterium ( diphtheroids)- palisades or Chinese letters o Listeria |
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Term
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Definition
o Gardnerella vaginalis - coccobacilli |
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Term
Cellular appendages-Capsule |
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Definition
Exterior to the outer membrane. Referred to as the slime layer, or glycocalyx, is composed of high molecular weight polysaccharides. Protects bacteria from phagocytic attack by cells of the immune system and increases adherence of colonization surfaces |
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Term
Cellular appendages-Fimbriae or pili |
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Definition
long hair like structures that extend from the cell membrane. Help attach to host cell surfaces |
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Term
Cellular appendages-Flagella |
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Definition
complex structures embedded in cell envelope. Responsible for cell motility if present |
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Term
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Definition
Under adverse conditions some bacteria are able to form spores. Involves from an active cell to a dormant cell with a decrease in cytoplasm and an increase in the thickness of the cell envelope. Frequently found in microbes living in soil such as B. anthracis |
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Term
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Definition
Microorganisms that are commonly found on or in body sites of healthy persons a. Different body sites have different or the same flora depending on the local conditions |
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Term
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Definition
colonize an area for months or years |
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Term
Transient microbial flora |
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Definition
temporarily present at a site, does not normally occur or stay at a particular site. Usually eliminated by immune response or competition w other normal flora |
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Term
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Definition
Host person who has established pathogenic flora with no disease present, they are however capable of transmitting disease |
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Term
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Definition
The condition of being a carrier for a pathogenic organism a. May be Acute, short lived or transient b. May be Chronic, lasting months, years or permanently |
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Term
Factors that Affect Normal Flora-Environmental Factors |
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Definition
a. Factors such as temperature, moisture. b. pH of the site has a great effect on colonization, as in the female genital tract where the normal pH in women of child bearing age is a very acidic 4.0-5.0. Most bacteria cannot survive in an environment with such a low pH. |
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Factors that Affect Normal Flora-Nutritional Factors |
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Definition
a. Presence of chemicals unique to certain body sites and uniquely used by certain species of organisms. presence of chemicals such as lipids (fats), bile, lysozymes, and fatty acids all affect the composition of organisms colonizing each area individually. Ex. Propionibacterium acnes colonize the ducts of hair follicles because it is able to break down the skin lipids into fatty acids |
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Term
Sterile Body Sites- Lower Respiratory Tract(were specimen and testing for) |
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Definition
Trachea, bronchi and lungs a. Specimen- Sputum, bronchial lavage b. Pathogens I. Streptococcus pneumonia ii. H. influenzae |
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Term
Sterile Body Sites-Upper Genitourinary Tract-(were specimen and testing for) |
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Definition
a. Specimen – Cath Urine, Surgical specimens b. Pathogens- generally coliform bacteria cause infections of the urinary tract i. E. coli ii. Proteus mirabilis iii. Staph saprophyticus |
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Term
Sterile Body Sites-CNS-(were specimen and testing for) |
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Definition
Brain, spinal cord and Cerebral Spinal fluid a. Specimen – CSF cerebral spinal fluid b. Pathogens i. E. coli ii. Neisseria meningitis |
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Term
Sterile Body Sites-Peritoneal Cavity(were specimen and testing for) |
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Definition
(abdominal cavity) a. Specimen – Ascites fluid b. Pathogens – Coliform bacteria from GI tract |
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Term
Sterile Body Sites-Synovial capsules(were specimen and testing for) |
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Definition
( fluid filled joints) a.Specimen – synovial fluid b. Pathogens i. N. gonorrhoeae ii. Staphylococcus aureus |
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Sterile Body Sites-Blood(were specimen and testing for) |
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Definition
a. Specimen – blood cultures are collected directly from the blood stream into enriched broth for incubation b. Pathogens – Many i. E. Coli, Staph aureus ii. Almost any infection site can become systemic when the bacteria from an infection site enter the blood stream and multiply iii. Condition known as Sepsis or Septicemia indicated by abrupt onset of fever and chills iv. Can be Aerobic or Anaerobic bacteria |
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Term
Laboratory diagnosis of infectious diseases involves |
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Definition
Direct examination of patient specimens for presence of etiologic agents ( bacteria, fungi) and for sample integrity. o Direct exam of a wet prep mount of vaginal secretions for report of white blood cells, trichomonas, yeast cells and clue cells o KOH prep – used to dissolve skins cells and detect the presence of fungal elements Isolation, growth and cultivation of the microbes Analysis of the cultivated organisms to establish identification |
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Term
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Definition
Methylene blue – imparts the same color to all parts |
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Term
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Definition
Gram Stain o Acid-fast Stain – Used to Stain Mycobacteria o Capsular Stain – o Endospore Stain o Flagella Stain |
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Term
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Definition
Primary Stain – crystal violet Mordant – iodine Decolorizer- alcohol or acetone Secondary Stain – Safrinin Gram positive organisms retain the purple crystal violet coloration Gram negative organisms release the crystal violet/iodine complex and stain pink with the Safrinin White blood cells appear pink to reddish orange in a gram stained specimen as opposed to the purple color seen in a Wright Stained blood smear |
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Term
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Definition
India Ink – dark background for use in visualizing the capsule surrounding certain organisms such as the yeast Cryptococcus which has a large capsule |
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Term
Specimen Collection and Handling-Wounds |
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Definition
a) Swabs are easily contaminated and dry out quickly b) If used, usually are placed in transport gel to retain specimen integrity c) Deep wound or abscess specimens are best collected by needle aspiration, NOT SWABS d) Note the type of sample and the anatomical site of collection |
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Term
Specimen Collection and Handling-Urine |
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Definition
clean-catch or nurse collected catheter specimen |
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Term
Specimen Collection and Handling-Sputum |
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Definition
a) Sputum samples may be refrigerated for transport in a sterile container b) Sputum vs. Saliva i) Sputum samples are gram stained upon receipt in the lab to determine specimen integrity. Specimens with >24 epithelial cells and multiple organisms are generally rejected due to contamination with oral flora. |
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Term
Specimen Collection and Handling-Spinal Fluid |
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Definition
suspected meningitis a) Should be handled stat and processed immediately. b) Gram stain always performed, normal specimen is sterile, no organisms seen c) Cultures are performed with specimen inoculated to chocolate agar and thio broth to enhance chances of recovering fastidious organisms d) May be held at 370c up to 6 hours prior to culture if needed |
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Term
Specimen Collection and Handling-Fecal Specimens |
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Definition
a) Collected to diagnose GI pathogens such as Salmonella and Shigella, common food poisoning assoc. organisms b) Preserve at 7.0pH if testing is to be delayed c) Special preservative vials are used for O&P samples to preserve those organisms |
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Term
Specimen Collection and Handling-Blood Cultures |
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Definition
collected directly into broth bottles a) Used to diagnose Bacteremia or Septicemia b) Sterile technique is imperative in collection of samples c) Normally collected at least two times form two different sites d) Avoid refrigeration |
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Term
Specimen Collection and Handling-Throat |
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Definition
a) Usually 2 swabs are collected, one may be used for rapid testing of Group A Beta Strep (S. pyogenes) b) The Second swab is used for culture c) Transport within one hour |
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Term
Specimen Collection and Handling-Anaerobic organisms |
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Definition
Some are very sensitive to environmental changes and will not be recovered on culture if not handled properly. a) Obligate Anaerobes – cannot live in the presence of oxygen. i) Specimens for anaerobes must be places immediately into anaerobic transport gel to preserve those organisms b) Facultative Anaerobes – many organisms isolated from the GI tract are facultative anaerobes. They can grow with or without the presence of oxygen. |
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