MDL246 - Module 1 Learning Objectives

Describe the specimens that are acceptable for anaerobic culture.

wound, pleural fluid, brain abscess

Describe how anaerobes are cultured.

incubator or jar

Identify appropriate specimen source and media combinations for endocervical specimens, throat swabs (for Strep culture), sputum, wounds, CSF, and urine including patient preparation for each

Endocervical- CHOC, TM.

Throat- BAP.

Sputum- BAP, CHOC, MAC.

Wounds- BAP, CHOC, MAC.

CSF- BAP, CHOC, Broth.

Urine- BAP, MAC.

Differentiate enrichment media, selective media, and nutritive (supportive) media, in terms of purpose, culture ingredients, and use and provides examples of each

Enriched- Contains supplements. Enhance the growth of fastidious organisms (ex: TM for Neisseria). Examples are CHOC and BYCE (Buffered Charcoal Yeast Extract).

Selective- Contain antibiotics. Select for the growth of certain organisms. Examples are MAC and PEA

Differential- Contains factors that allow colonies of one bacterial species/type to exhibit specific culture characteristics. Examples are MAC and BAP

Supportive- Antibiotic removal (ARDs in blood culture media). Examples are BAP and CHOC.

Describe the chain of infection, including how to break the chain.

Wash your hands! The chain of infection is the cascade in which a pathogen causes infection in a host. It starts with the Pathogen, Exit, Route of Transmission, Entry, and Host

Describe examples of the spread of pathogens through direct contact

Droplet infection, smear infection, or $exual contact

Identify examples of organisms that are positive for forming endospores, using the spore stain.

bacillus and clostridium

Provide examples of common normal flora for the major body sites

Staphylococcus epidermidis

Escheria coli

Streptococcus viridans

Differentiate the types of hemolysis on a blood agar plate, including how it works and common organisms for each

Alpha- ph, green

Beta- clear agar under and around bacteria (or hazy)

Gamma- no hemolysis

Discuss MacConkey media in terms of purpose, key characteristics, common examples and how it works.

Differential and selective. Gram negative and lactose fermentation. Pink= lactose fermentation

Identify examples of organisms that are not able to grow on sheep blood agar plates but can grow on chocolate agar plates

Identify morphologic characteristics of Trichomonas vaginalis

Discuss Hektoen agar media in terms of purpose, key characteristics, common examples and how it works.

Describe the purpose of evaluating positive cultures.

Identify terms used to describe colony size and pigment

Describe how biological safety cabinets work to protect the laboratory worker

Protect lab workers from aerosol exposure to infectious disease agents. Class I only sterilizes exhausted air. Class II sterilizes air coming in and out (laminar flow hoods). Class III sterilizes air coming in and out, and cabinet is sealed so material within must be handled with attached gloves

Describe the safe handling and disposal of laboratory generated infectious wastes

Dispose of sharp objects in the sharps container, whether potentially infectious or not. Dispose of biohazardous waste in the biohazard bin. Most of the chemicals used in the microbiology laboratory can be washed down the drain.

Describe the purpose of transport media

Identify specimens which would be acceptable for anaerobic culture

Identify examples of bacterial colony shape or surface appearance

coccus, strepto, staphylo,

Describe the function of the Clinical Microbiology Laboratory

Identify media that is inhibitory and describe how inoculate of multiple plates occurs when some of the plates are inhibitory

Inoculate in order from least inhibitory to most inhibitory. CHOC, BAP, then MAC

Compare and contrast semi-quantitation and quantitation of organisms including how the media is streaked and how the results are reported.

Quantitation- purpose is just to see if it will grow and how much will grow, inoculated with one swipe down middle of the plate and then zig zag across said swipe in order to cover the whole plate.

Semi-quantitation- estimate the amount of bacteria and use normal quadrant streaking

Identify the purpose of the Calcofluor White stain and the India Ink stain

India Ink stain- demonstrate the presence of encapsulated bacteria and yeast in a CSF specimen

Calcoflour White stain- fluorescent stain for yeast and fungus

Describe how and where media inoculation of microbiological specimens is performed

under the hood

Describe when it is appropriate to perform gram staining on a primary specimen and when it should not be performed.

when verifying the quality of a specimen example CSF or throat swab. not appropriate for stool or endocervical

Describe the common growth requirements for most bacterial pathogens, including atmosphere and incubation temperature

35-37 aerobic or ambient