Hazards of Working with Biological Organisms and Material pedia/commons/e/ee/Reconstru cted_Spanish_Flu_Virus.jpg Reconstructed Spanish flu

Working with Fungi Fungi and molds everywhere – Mycosis disease caused by infection –Toxicity from mycotoxins –Allergies airborne spores day_old_Aspergillus_colonies_on_a_Petri_dish.png Photo: Adrian J. Hunter

Hazards of Working with Viruses Integration of viral genome content/uploads/2010/09/hiv_biology.gif

Calculating Risk Level Viruses differ in infectiousness Hepatitis B virions

Calculating Risk Level Different viruses have different consequences –HBV causes Hepatitis B –HIV causes AIDS Treatment or vaccine?

Viruses and Cancer Some viruses are oncogenic Moderate risk viruses –Include: papilloma virus, herpes virus, Epstein-Barr virus, and the Hepatitis B and C viruses irus_(HPV)_EM.jpg HPV

Working with Human Blood Products “Universal Precautions” –Minimizing use of needles and sharps and proper disposal of these –Wearing PPE –Decontaminating all work surfaces frequently –Decontaminating waste –Frequent hand washing –Biohazard sign posting

Working with Tissue Culture Tissue culture = in vitro propagation of cells taken from tissue of higher organism haithemsciences.com/Images/Cell _Culture_Mgt.jpg enetics.com/Portals /4/fibroblasts%20ph ase%20contrast.JP G

Primary Cell Culture –Newly isolated cells from tissue or blood –Can be infectious Note cells migrating from piece of tissue

Established cell lines –Many generations in culture –Less likely to pose unknown threat mmons/6/6c/HeLa_cells_stained_with_H oechst_33258.jpg Cultured HeLa cells

Disposal of Biohazardous Waste Biohazard waste –Discarded cultures of bacteria or cell culture –Out of date stock cultures –Human and animal waste –Used culture dishes and tubes –Biologically contaminated sharps Disposal –Place in labeled, closable, leak-proof bags –Place bags in secondary containers to prevent punctures –Usually decontaminate by autoclaving

Routine Clean-up: Disinfection Removal of all or almost all pathogens on a surface

Disinfectant Characteristics Chemicals that kill pathogenic microorganisms and other hazardous particles Ideal: –Broad spectrum –Water-soluble –Low toxicity –Inexpensive No ideal disinfectants

Factors affecting the effectiveness of disinfectants –Type of organism Least resistant: viruses like HIV, Herpes and Hepatitis B Then Bacteria Then Fungi Then small viruses like polio and rhinoviruses Most resistant are bacterial spores Bacterial spore

Disinfectants Effectiveness also affected by –Level of contamination –Chemical composition and concentration of disinfectant –Length of exposure to disinfectant –Texture of surface to be disinfected

Choosing disinfectants Low— –gets rid of most bacteria and SOME viruses and fungi –used for routine clean-up and decontamination Intermediate— –gets rid of most bacteria, viruses and fungi –Not spores –includes phenolics and 500 ppm chlorine bleach –used for clean-up of bodily fluids wikipedia/commons/9/93/Ag ar_plate_with_colonies.jpg _Blood_cells.jpg

Choosing disinfectants High— –gets rid of all microorganisms except large number of bacterial spores –included H 2 O 2 and 1000 ppm chlorine bleach –used for instruments that can not be autoclaved d.wikimedi a.org/wikip edia/comm ons/1/12/B acillus_ant hracis.png Bacillus anthracis containing spores (anthrax)

Sanitization General reduction of number of microbes on surface –antiseptic ages/Antibacterial_Hand_Soap.jpg

Sterilization Killing of all organisms on a surface oclave.jpg Autoclave

Biohazard spills For personal contamination –Remove all contaminated clothing and soak lab coats in bleach prior to washing –Wash skin areas vigorously for at least 10 minutes –Use an antiseptic if available –Inform supervisor immediately

Biohazard Spills For a small spill with a BSL-1 or BSL-2 organism –Wear protective clothing –Soak up spill with absorbent towels soaked in disinfectant (ie 10% bleach) –Dispose of towels in biohazard waste –Clean spill area with fresh towels and disinfectant erUploadedImages/102/ZEO- BZ001%20-%2072dpi%20800px.jpg

Biohazard spills For a BSL-2 organism: –First evacuate for 10 min. to let aerosols settle –Cover main spill area with towels soaked in disinfectant. Then flood secondary area with disinfectant. –Place all waste in biohazard bags. –Put additional disinfectant over spill area and let sit for at least 20 minutes for decontamination.