MICROBIOLOGY.pptx unit Vmethods of control and destruction of microbes

This content under gnm syllabus.unit V various methods of control and destruction of microbes
Sterilization
Disinfection
Chemotherapy and antibiotics
Pasteurization
Medical and surgical asepsis
Bio medical waste management

1. MICROBIOLOGY UNIT V

2. CONTROL AND DESTRUCTION OF MICROBES Principles and methods of microbial control Sterilization Disinfection Chemotherapy Antibiotics Pasteurization

3. STERILIZATION

4. DEFINITION Sterilization describes a process that destroys or eliminates all forms of microbial life and is carried out in health care facilities by physical or chemical methods.

5. METHODS OF STERILIATION

6. Cont… S un light: It is a natural method of sterilization, it under natural condition e.g sterilization of water in tank, rivers and lakes . It has germicidal activity due to ultraviolet rays present in it. Drying: moisture is required for the growth of microbes. drying in air reduces the moisture content and produces deleterious effects.

7. HEAT Heat is most reliable methods of sterilization. It is the method of choice for material, which are not damaged by heat. T here are 2 types of heat . Dry heat . Moist heat Dry heat : Dry heat is preferred for sterilization of glassware such as glass syringe , test tube, petri plates. It is unsuitable for material such as fabrics, which may be damaged by heat.

8. Dry heat can be used in the following ways- a . Red heat It is an easy way of sterilization, but has limited application. Used for sterilization nonflammable material such as tip of forceps ,scissors and spatula. It is direct heating of instrument or object. b. Incineration : This is direct burning of materials at high temperature(800c-1000c ). Used for destroying materials such as soiled dressing, bedding patient , pathological materials.

9. Cont….. C. Flaming : Direct exposure for a few seconds by passing a few times through the Bunsen flame. May be used for scalpels, needles, glass slides, mouth of culture tube etc… d. Hot air oven : Hot air oven is the most widely used method of sterilization by dry heat. It has two walled chamber. -Inner wall of copper vessel -Outer wall of asbestos to reduce radiation of heat.

10. Parts of hot air oven

11. Cont… Thermometer is inserted at one of the corners. It is heated by electricity, with heating elements in the wall of the chamber. A fan is also fitted to ensure even distribution of air and elimination of air pockets. It is operated at 160c for one hour or 180c for 30 minutes. the thermometer is adjusted at the required level and recorded with the help of thermometer.

12. Cont.. After the specific time , electricity is cut down and material is allowed to cool. All glassware to be sterilized are covered with craft paper in a chamber. it allows fess circulation of air in between the object. On cooling , the material is taken from oven and used .

13. Hot air oven

14. Uses of hot air oven For sterilization of swabs. Used for sterilization of forceps ,scissors , scalpels, other surgical instruments. For sterilization of pharmaceutical products and glassware , pipettes , test tubes , glass bottles. Precautions : It should be not be overloaded. Glassware must be free from water traces and properly covered with papers. Any inflammable material should not be kept inside the oven. T he material should be properly arranged to allow free circulation of air .

15. Cont…. moist heat: It is efficient than dry heat in penetrating the material. It is commonly used for the sterilization of culture media prior to washing, laboratory coat , apron, glass syringe , surgical instruments. moist heat may be employed in following ways: A .Temperature below at100 c B. Temperature at 100 c C. Temperature at above 100 c

16. a.Temperature below 100 c Pasteurization: Holder method Flash method   Pasteurization • 63 C  for 30 minutes for holder method • Flash method 72 C for 15- 20 seconds followed by quick cooling to lower temperature .

17. Boiling: Boiling at 100 c for 10- 30 minutes kills almost all vegetative bacteria but does not ensure complete sterilization. Recommended for sterilization of pipettes , cylinder, rubber stoppers , scalpels forceps, scissors, etc. Not recommended for the sterilization of instruments used for surgical procedures. 2. Steaming: steaming at atmospheric pressure at 100c is used to sterilize culture media. One exposure for 90 minutes ensures complete sterilization. B.Temperature at 100 c

18. 3.Tyndallization: In this steaming of object is done at 100c for 30 minutes on three successive days. This ensure complete removal of spores, which might not be killed by a single steaming. The spores present will germinate on successive days and will be killed by second and third exposure.

19. c . Temperature above 100c It is the mostly widely used method of sterilization. Sterilization by steam under pressure is carried out at temperature between 108 C to 147 C. Dressing material, instruments, laboratory wares pharmaceutical products an be sterilized.

20. autoclave An autoclave is used to sterilize various requirements in the laboratory by wet sterilization method. According to boyle’s law when volume of the steam is kept constant the steam is kept constant, the temperature is directly proportional to pressure. At 15lbs pressure 121 degree Celsius temperature can be obtained. Moist heat coagulates cell proteins of the microorganisms and thus kills all the living entities in 15 to 25 minutes.

21. parts

22. Cont.. Precautions : Never heat too quickly to bring up the pressure and never leave the autoclave unattended while the pressure is rising. Never leave the autoclave to cool for too long without keeping the outflow valve open. Uses: All solid and liquid media, distilled water, saline solution, laboratory coats, swabs, syringes and needles, surgical instruments, dressing and pharmaceutical products .

23. filtration These thermolabile materials are made free from organisms by passing through filters. Filters are used for removal of microorganisms from the fluids or liquids that are thermolabile. Filtration is usually carried out under negative pressure.

24. Types of filters:

25. Cont… Candle filters : Used for purification of water on large scale. Asbestos filters: Composed of asbestos fibers. Disposable , single- use disc. Disadvantages : - alkalinize filtered liquids. -Has carcinogenic potential .

26. Cont… Membrane filters: Composed of cellulose esters and are called millipore or polypore filter. Available range of different range of pore size(0.05-12micron). Used for -water purification and analysis. -sterilization and sterility testing. Most suitable for preparing sterile solutions.

27. radiation The radiation has effect on microorganisms because they absorbs radiant energy. T ypes of radiation: 1.IONIZING RADIATION 2.NON IONIZING RADIATION (UVRAYS)

28. 1.Ionizing radiation : These include gamma rays, beta rays and x rays etc.. These are highly lethal to DNA and other vital cell constituents. They have high penetrating power. Gamma and beta rays are extensively used in industry mainly for sterilization of instruments and dressing pack such as plastic syringe ,swab>

29. Non-ionizing radiation (UV rays): There are short rays (wavelength 210-310nm) having low penetrating power. The wavelength between 240-280nm especially 254 nm is most efficient in sterilization. UV rays are able to kill cells, temporarily delay cell division and also the synthesis of certain substances by cell. most effective in absence of oxygen.

30. Cont.. Sources: UV rays are components of sunlight, sunlight has got bactericidal activity. UV rays can be produced artificially by special UV lamp. Application : In the control of air borne infections by air disinfection. Disinfection of drinking water.

31. ii.Chemical agents Several chemical agents are used as antiseptics and disinfectants. a. Alcohols: Ethyl alcohol and isopropyl alcohol are the most frequent used. Mainly used to disinfect skin and decontaminate clean surface. Methyl alcohol is effective against fungal spores ,vegetative bacteria.

32. Alcohol antiseptic

33. b. Aldehydes: Formaldehyde is used for sterilizing instruments and heat sensitive catheters and for fumigating wards , sick rooms and laboratories. c. Dyes: Dyes are used extensively as skin and wound antiseptics. Both are bacteriostatic in high dilution but are of low bactericidal activity. d. Halogens: Iodine in aqueous and alcoholic solution has been used widely as a skin infectant . It active against the tuberculous bacteria and viruses .

34. Cont… e. chlorine: chlorine and its compounds have been used as disinfectants for many years, water supplies swimming pools, food and dairy industries use chlorine. f. phenols: Various combinations of phenols are used in the control of pyogenic cocci in surgical and neonatal units of hospital.

35. iii. gases a.Ethylene oxide: This is a colorless liquid with a boiling point of 107 C and normal temperature and pressure is a highly penetrating gas with a sweet ethanol smell. It is specially used for sterilizing heart and lung machines, respirators, dental equipment, book and clothing. b.Formaldehyde gas: this is widely employed for fumigation of operation theatres and other rooms.

36. chemotherapy Definition : T he treatment of a disease with a chemical substance is known as chemotherapy and the chemical substance is called ‘chemo- therapeutic agents or drug ’. S ynthetic antibacterial Drugs: The group of synthetic antibacterial drugs includes 1.sulphonamides 2.Trimethoprim 3.Cotrimaxazole 4. Quinolones

37. 1.Sulphonamides: Mode of administration: sulpha drugs are normally given orally . Some are available as eye drops and eye ointments. Spectrum of activity : drugs are effective against a wide range of bacteria such as streptococcus pyogenes , Neisseria meningitis, E.coli .

38. Cont.. 2.Trimethoprim: I t is a broad spectrum drug and is similar to sulphonamides in mode of activity as well as spectrum of activity. It is marketed under trade name spectra. Spectrum: It is effective against many common pathogenic bacteria such as staphylococci , cornye bacterium diphtheria, salmonella shigella, vibrio cholerae . Side effects: Few patients may experience rashes, nausea and vomiting.

39. CONT…. 3.Cotrimoxazole: Administration: oral intramuscular, intravenous. Mode of action : it is bacteriostatic drugs. Spectrum : It is having broad spectrum activity against both gram positive and negative bacteria. Clinical uses : widely used for urinary and respiratory tract infection. Side effects: Nausea, vomiting, rashes, mouth ulceration.

40. Cont… 4.Quinoloes : These are broad spectrum synthetic drugs. Ciprofloxacin, norfloxacin and endofloxacin are the derivatives of nalidixic acid by addition of fluorine and are fluoroquinolones. Administration : mainly oral, also intravenous. Clinical uses : there are currently used in treating urinary tract infection, sexually transmitted disease, gastrointestinal infection, skin disease. Side effects : In general, these drugs are well tolerated

41. ANTIBIOTICS DEFINITION: Antibiotic are chemical compound produced by living microorganisms where in small concentration inhibit the growth of other micro organisms. Names: penicillin cephalosporin tetracycline quinolones

42. Cont.. PENICILLIN: Discovery : Flemming in 1929. Produced by: fungus penicillin species. Mode of action : inhibition of cell wall synthesis batericial

43. CONT…. CLASSIFICATION: Natural- benzyl penicillin –active against gram + ve . Semisynthetic penicillinase resistant-methicillin. Extended spectrum-amino penicillin , carboxyl penicillin.

44. PASTEURISATION DEFINITION: Heating of milk or other liquids to moderate temperature for a definite time, often 60 degree for 30 min. which kills most pathogenic bacteria. Uses : When strong heat may harm the quality of production as of market milk. When our aim is to kill pathogens as a in market milk. When the spoilage organisms are not heat resistant as in juices.

45. Methods of pasteurization Low temperature long time method: I n this method the temperature employed for sterilization is 63 degree for 30 minutes. High temperature short time method : In this method the temperature employed for sterilization is 71.2 degree for 15-20 seconds. Ultra pasteurization: high temperature is used for relatively short period of time 137 degree Celsius for two seconds in market milk.

46. Medical and surgical asepsis Asepsis: It is the freedom from disease causing micro organisms. In order to decrease the possibility of transferring micro organisms from one place to another place . Medical asepsis : medical asepsis refers to all practices the patients and his environment from the transmission of disease producing organisms (preventing of cross infection).

47. MEDICAL ASEPSIS

48. CONT… Surgical asepsis : surgical asepsis refers to all the procedures used to keep objects or areas sterile or completely free from all microorganisms.

49. Surgical asepsis

50. Bio safety and waste management DEFINITION: biosafety is the protective process involving various procedure and policies that are involved in ensuring a consistently safe atmosphere to the health care personnel, laboratory workers, etc…

51. Biosafety level

52. Cont… Bio medical waste is specifically the infectious waste that all or any one of the following categories like: H uman or animal diagnostic, treatment, or the immunizing procedure. The waste produced the related research activities. The waste formed during the manufacturing or testing of the immuno biological. The waste formed in any of the health camps activities.

53. Categories of biomedical waste management BMW segregation : BMW segregation means the separation of the mixed waste specifically at its point of generation as per the color coding specified under the BMWM rules. BMW collection : the collection is the process of taking away the segregated biomedical waste from its every point of generation in an HCF to be transported to the storage area with in the HCF.

54. CONT…. BMW transportation: The transportation trolleys must be used for the in house transportation. BMW storage(central waste collection room): must be away from the traffic areas with sufficient space and no general waste should be stored in here.

55. Categories of biomedical waste categories Biomedical waste type Description Category 1 Human anatomical waste Human tissues, human organ the human body parts and fetus below the viability period(MTP ACT1972) Category 2 Animal anatomical waste Experimental animal carcasses, animal body parts, animal body organ and tissues & the waste products from the experiments and tests conducted in veterinary hospital. Category 3 Solid waste Blood and body fluids contaminated items- dressings, plaster casts, cotton swabs and bags with blood components

56. Cont… categories Bio medical waste type Description Category 4 Discarded or expired medicine Pharmaceutical waste like antibiotics, cytotoxic drugs, glass/ plastic ampoules, vials Category 5 Chemical waste Generated during the production in biological and the discarded/used disinfectants Category 6 Chemical liquid waste Silver x ray film developing liquid, discarded formalin, infected secretions, aspirated body fluids, lab waste, floor washing liquids.

57. cont.… categories Bio medical waste type Description Category 7 Blood and body fluid contaminated linen, mattresses, bedding routine gown, mask Discarded linen contaminated with blood and body fluid, mask, head cover shoe covers disposable gown Category 8 Microbiology, biotechnology and other clinical laboratory Blood bags, laboratory culture, microbial stocks/ specimen, live or attenuated vaccines/ dishes used for culture Category 9 Disposable plastic waste items Tubing, bottles, intravenous sets/ tubes, catheters, urine bags, needles syringes, and gloves

58. Cont… categories Bio medical waste type Description Category 10 Used, discarded and contaminated waste sharp Used , discarded and contaminated metal sharps, needle syringes with fixed needles, needle tip cutter/ burner needle, puncture needle Category 11 Broken, discarded and contaminated glass excepts with cytotoxic waste and metallic implants Medicine vials and ampoules excepts those with cytotoxic waste and metallic body implants Category 12 General waste Kitchen waste, paper and tissues, water bottles, and cans,

59. Bmw segregation Yellow: human anatomical waste animal anatomical waste soiled waste discarded or expired medicine chemical waste Microbiology and biotechnology and other laboratory waste routine gowns and mask

60. Cont… Red : Recyclable contaminated waste / disposable plastic Waste items.