Fastidious microorganisms and safety precautions in microbiology lab

Fastidious microorganisms and safety precautions in microbiology lab - Dr. S. Sivasankara Narayani

1. 20UYC101 –Fundamentals of Microbiology – UniT V – Nutritional Types Dr. S. Sivasankara Narayani Assistant professor Department of Microbiology Ayya nadar Janaki ammal college sivakasi 07/09/20 Dr.SS

2. UNIT - III NUTRITIONAL REQUIREMENT AND MEDIA PREPARATION Nutritional requirements: Nutritional types of microbes- autotrophs - phototrophs, chemotrophs - organotrophs- lithotrophs – mixotrophs. Fastidious microorganism. Safety precautions adopted in microbiology laboratories. *Aseptic techniques: Physical methods - chemical methods. Different forms of media preparation: Nutrient broth – agar slope- agar deep -agar plate – semi solid - solid media. Types of culture media: Simple- enriched- enrichment- selective- differential - transport. 07/09/20 Dr.SS

3. Fastidious organism A  fastidious organism  is any  organism  that has complex or particular  nutritional  requirements. In other words, a fastidious organism will only grow when specific nutrients are included in its medium. The more restrictive term  fastidious microorganism  is used in  microbiology  to describe  microorganisms  that will grow only if special nutrients are present in their  culture medium . Thus  fastidiousness  is often practically defined as being difficult to   culture , by any method yet tried. An example of a fastidious  bacterium  is  Neisseria gonorrhoeae , which requires blood or hemoglobin and several amino acids and vitamins to grow.  Other examples include  Campylobacter  spp .  and  Helicobacter  spp . , which are  capnophilic  – require elevated  CO 2  – among other requirements. Fastidious organisms are not inherently "weak"—they can flourish and thrive in their particular ecological niche with its particular nutrients, temperature, and absence of competitors, and they can be quite difficult to kill off. But they are difficult to culture simply because it is difficult to accurately simulate their natural milieu in a  culture medium . For example,  Treponema pallidum   is not easy to culture, yet it is resilient in its preferred environment, being difficult to eradicate from all tissues of a person with  syphilis . 07/09/20 Dr.SS

4. Safety precautions adopted in microbiology laboratories 07/09/20 Dr.SS

5. Treat all microorganisms as potential pathogens While the majority of microorganisms are not pathogenic to humans and have never been shown to cause illness, under unusual circumstances a few microorganisms that are not normally pathogenic can act as pathogens. Treat all microorganisms—especially unknown cultures—as if they were pathogenic. A student who has a compromised immune system or has had a recent extended illness should talk with the instructor before working in the microbiology laboratory.

6. Sterilize equipment and materials All materials, media, tubes, plates, loops, needles, pipetes , and other items used for culturing microorganisms should be sterilized by autoclaving. Otherwise, use commercially sterilized products. Understand the operation and safe use of all equipment and materials needed for the laboratory.

7. Disinfect work areas before and after use Use a disinfectant, such as a 10% bleach or 70% ethanol solution, to wipe down benches and work areas both before and after working with cultures. Also be aware of the possible dangers of the disinfectant, as 70% ethanol can catch fire around open flame or high heat sources. Bleach, if spilled, can ruin your clothing. Either alcohol or bleach can be dangerous if splashed in the eyes. Students should know where the nearest eyewash station and sink are located.

8. Wash your hands Use a disinfectant soap to wash your hands before and after working with microorganisms. Nondisinfectant soap will remove surface bacteria and can be used if disinfectant soap is not available. Gloves may be worn as extra protection.

9. Never pipette by mouth Use pipette bulbs or pipetting devices for the aspiration and dispensing of liquid cultures

10. Do not eat or drink in the lab, nor store food in areas where microorganisms are stored.   Never eat or drink in the laboratory while working with microorganisms. Keep your fingers out of your mouth, and wash your hands before and after the laboratory activity. Cover any cuts on your hands with a bandage. Gloves may be worn as extra protectio

11. Label everything clearly. All cultures, chemicals, disinfectant, and media should be clearly and securely labeled with their names and dates. If they are hazardous, label them with proper warning and hazardous information.

12. Autoclave or disinfect all waste material All items to be discarded after a class, such as culture tubes, culture plates, swabs, toothpicks, wipes, disposable transfer needles, and gloves, should be placed in a biohazard autoclave bag and autoclaved 30 to 40 minutes at 121° C at 20 pounds of pressure. If no autoclave is available and you are not working with pathogens, the materials can be covered with a 10% bleach solution and allowed to soak for at least 1 to 2 hours

13. Clean up spills with care  Cover any spills or broken culture tubes with a 70% ethanol or 10% bleach solution; then cover with paper towels. After allowing the spill to sit with the disinfectant for a short time, carefully clean up and place the materials in a biohazard autoclave bag to be autoclaved. Wash the area again with disinfectant.  Never  pick up glass fragments with your fingers or stick your fingers into the culture itself; instead, use a brush and dustpan. If working with animal or plant pathogens, keep the area clear and notify your instructor.

14. Safety rules in labs Know locations of laboratory safety showers, eyewashstations , and fire extinguishers. The safety equipment may be located in the hallway near the laboratory entrance. Know emergency exit routes. Avoid skin and eye contact with all chemicals. Minimize all chemical exposures. No horseplay will be tolerated. Assume that all chemicals of unknown toxicity are highly toxic. Post warning signs when unusual hazards, hazardous materials, hazardous equipment, or other special conditions are present. Avoid distracting or startling persons working in the laboratory. Use equipment only for its designated purpose. Combine reagents in their appropriate order, such as adding acid to water. . 07/09/20 Dr.SS

15. Cont.. Avoid adding solids to hot liquids. All laboratory personnel should place emphasis on safety and chemical hygiene at all times. Never leave containersof chemicals open. All containersmust have appropriate labels. Unlabeled chemicals should never be used. Do not taste or intentionally sniff chemicals. Never consume and/or store food or beverages or apply cosmetics in areas where hazardous chemicalsare used or stored. Do not use mouth suction for pipetting or starting a siphon. Wash exposed areas of the skin prior to leaving the laboratory. Long hair and loose clothing must be pulled back and secured from entanglement or potential capture. No contact lenses should be worn around hazardous chemicals – even when wearing safety glasses. Laboratory safety glasses or goggles should be worn in any area where chemicals are used or stored. They should also be worn any time there is a chance of splashes or particulates to enter the eye. Closed toe shoes will be worn at all times in the laboratory. Perforated shoes or sandals are not appropriate 07/09/20 Dr.SS

16. Cont.. Determine the potential hazards and appropriate safety precautions before beginning any work. Procedures should be developed that minimize the formation and dispersion of aerosols. If an unknown chemical is produced in the laboratory, the material should be considered hazardous. Do not pour chemicals down drains. Do NOT utilize the sewer for chemical waste disposal. Keep all sink traps (including cup sink traps and floor drains) filled with water by running water down the drain at least monthly. Do not utilize fume hoods for evaporations and disposal of volatile solvents. Perform work with hazardous chemicalsin a properly working fume hoodto reduce potential exposures. 07/09/20 Dr.SS

17. Cont.. Avoid working alone in a building. Do not work alone in a laboratory if the procedures being conducted are hazardous. The PEL and the Threshold Limit Values (TLV) will be observed in all areas. If exposure above a PEL/TLV is suspected for an ongoing process, please contact EHS immediately. Laboratory employees should have access to a chemical inventory list, applicable SDSs, Department Laboratory Safety Manual, and relevant SOPs. Access to laboratories and support areas such as stockrooms, specialized laboratories, etc. should be limited to approved personnel only. All equipment should be regularly inspected for wear or deterioration. Equipment should be maintained according to the manufacturer’s requirements and records of certification, maintenance, or repairs should be maintained for the life of the equipment. Designated and well-marked waste storage locations are necessary. No cell phone or ear phone usage in the active portion of the laboratories, or during experimental operations. Clothing made of synthetic fibers should not be worn while working with flammable liquids or when a fire hazard is present as these materials tend to melt and stick to exposed skin. Laboratory coats should not be stored in offices or break rooms as this spreads contaminates to other areas. Computers and instrumentation should be labeled to indicate whether gloves should be worn or not. Inconsistent glove use around keyboards/keypads is a source of potential contamination. Avoid wearing jewelry in the lab as this can pose multiple safety hazards 07/09/20 Dr.SS

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19. Clarification 07/09/20 Dr.SS [email protected]

20. Questions to think Fastidious microorganisms Safety precautions adapted in microbiology lab 07/09/20 Dr.SS

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