Chapter 5

How big of a filter will only remove bacteria?

0.45 micrometers

Prions are thought to be sterilized at ______ degrees celsius for _______

132, 1 hour

BOILING

BOILING FOR 5 MIN DESTROYS MOST MICROORGANISMS AND VIRUSES, NOT ENDOSPORES 5 MIN: TREAT DRINKING WATER destroys most microorganisms and viruses doesn't sterilize, endospores can live

Types of Moist Heat

BOILING, PASTEURIZATION, AND PRESSURIZED STEAM (AUTOCLAVING)

Biosafety Levels

CDC guidelines for labs working with microbes range from BSL-1 to BSL-4

Critical Items

COMES IN CONTACT WITH BODY TISSUES NEEDS TO BE STERILE NEEDLES AND SCALPELS USED FOR HEART TRANSPLANTS

Semicritical Instruments

COMES IN CONTACT WITH MUCOUS MEMBRANES BUT DON'T PENETRATE BODY TISSUES CANNOT HAVE VIRUSES OR VEGETATIVE BACTERIA FEW ENDOSPORES BLOCKED BY MUCOUS MEMBRANES ENDOSCOPES, ENDOTRACHEAL TUBES, AND THERMOMETERS

DRY HEAT OVENS

DESTROYS CELL PARTS AND DENATURES PROTEINS LESS EFFICIENT THAN MOIST HEAT, NEEDS LONGER TIMES AND HIGHER TEMPS

FILTRATION OF FLUIDS

DIFFERENT PORES SIZES AVAILABLE 0.2 MICROMETERS IS COMMONLY USED TO REMOVE BACTERIA USED FOR BEER AND WINE AND TO STERILIZE SOME HEAT-SENSITIVE MEDS

TYPES OF FILTRATION

FILTRATION OF FLUIDS FILTRATION OF AIR

TYPES OF DRY HEAT

INCINERATION AND DRY HEAT OVENS

USES OF DRY HEAT OVENS

LAB GLASSWARE IS STERILIZED BY HEATING AT 160 TO 170 DEGREES CELSIUS FOR 2 TO 3 HOURS POWDERS, OILS, AND OTHER DRY MATERIALS ARE ALSO STERILIZED IN OVENS

Non-critical Instruments

ONLY TOUCH UNBROKEN SKIN LOW RISK OF TRANSMISSION COUNTERTOPS, STETHOSCOPES, BLOOD PRESSURE CUFFS DON'T NEED TO BE STERILIZED

High Pressure

PASTEURIZES AND PRESERVES CERTAIN COMMERCIAL FOOD PRODUCTS LIKE GUACAMOLE avoids problems with high temp pasteurization UP TO 13,000 PSI DESTROYS MICROBES BY DENATURING PROTEINS AND CHANGING CELL PERMEABILITY products maintain color and flavor associated with fresh food found in bottom of sea

Ultra-High-Temperature (UHT)

Shelf-stable boxed juice and milk aka ultra pasteurization milk: 140 degrees celsius for a few seconds, then rapidl cooled heating and cooling that destructs and denatures protein

Irradiation

approved to treat certain foods Mexico and Peru's vegetables are irradiated killing insects provides alternative, but damages some kinds of plastic gamma radiation short wavelengths can penetrate and kill organisms

Types of Highly Resistant Microbes

bacterial endospores, protozoan cysts and oocysts, Mycobacterium species, Pseudomonas species, and naked viruses

X-Rays

can damage DNA, but cannot kill bugs don't get it if you don't need it

Clostridium botulinum Endospores

can grow in canned food can make toxins that don't smell reduce 10 to the twelfth power to only 1 ( 12 D process) virtually impossible to have so many endospores

Bacterial Endospores

can only be completely destroyed in extreme heat or chemicals

Gamma Rays

can penetrate deep

Chemical Additives

can prevent spoilage

Ionizing Radiation

can remove electrons from atoms collect electrons from DNA and make radicals MAKES REACTIVE MOLECULES THAT DAMAGE OTHER CELL PARTS ITEMS CAN BE STERILIZED EVEN AFTER PACKAGING DESTROYS DNA DAMAGES CYTOPLASMIC MEMBRANES reacts with oxygen to make reactive oxygen species

Moist Heat

cannot be used to treat moisture-sensitive material pressure cookers and autoclaves moist heat is hotter permanently DENATURES PROTEINS boiling and pasteurization RELATIVELY FAST, RELIABLE, SAFE, AND INEXPENSIVE WIDELY USED

Crptosporidium parvum

causes diarrhea resistant to chemical disinfectants not killed with chlorination, first found in milwaukee

Beneficial skin microbata resides ______ on underlying layers of ____ and ________

deeper, skin, hair follicles

Preservation

delaying spoilage of foods and other perishable products adjust conditions add bacteriostatic preservatives putting food in freezer prevents microbes from growing

Principles of Control

different mechanisms to contain organisms sterilization, disinfection, decontamination, sanitized, preservation and pasteurization

What can interfere with heat, penetration, and action of chemicals?

dirt, grease, and body fluids important to thoroughly clean

Incineration

dry heat sterilization method oxidizes cell to ashes BURNS CELL PARTS TO ASHES destroys medical waste and animal carcasses lab inoculation loop sterilized by flaming swabs, gauze, and waste are incinerated in hospital

Radiation

electromagnetic radiation: radio waves, microwaves, visible and UV light, X rays, and gamma rays energy travels in waves, no mass TYPE OF CELL DAMANGE DEPENDS ON WAVELENGTH higher the wavelength, lower the frequency

Disinfection

eliminating most or all pathogens some viable microbes might stay always on surface very effective for killing flu (has a membrane) can use physical or mechanical method anticeptics and disinfectants

Commercially Sterile

endospores of some thermophiles can live usually not a concern; only grow at temps well above normal storage

UV

fairly strong, bad for skin and eyes, especially fair skin can only penetrate 2 mm in causes skin cancer directly destroys microbes DAMAGES DNA by making thiamin PENETRATES POORLY

T/F: pasteurization is a method of sterilization.

false

T/F: toxins will go away in the oven

false

How can chlorine react with natural chemicals?

form disinfection by-products (DBPs) some DBPs linked to long-term health risks

What has the FDA approved that gamma rays can be used on?

fruits, vegetables, grains, pork, poultry, beef, lamb, and pork

Important Forms of Ionizing Radiation

gamma rays and X rays used to sterilize heat-sensitive materials usually used after packing can be used on food, but consumer resistance has limited use

Decimal Reduction Time (D Value)

gauges commercial effectiveness time needed to kill 90% of population under specific conditions each D value is different for a different product used for heat, not hospitals

Sanitized

get a lot less microbial population that meets accepted health standards not a specific level of control

Decontamination

get less pathogens to a safe level to handle

Healthcare-Associated Infections

healthcare personnel: nurses, CNAs, doctors

Soap

helps mechanically remove organisms has mycels that will bind to dead skin and bacteria

Filtration of Air

high-efficiency particulate air (HEPA) filters get rid of almost all microbes from air some are charged, others aren't need sima holes expensive

Sodium Hypochlorite

household bleach can kill suspension of M. tuberculosis at 55 degrees Celsius in half the time as at 50 degrees Celsius freeze it: takes it half the time

Why is selecting an effective antimicrobial procedure complicated?

ideal method doesn't exist each method has drawbacks and procedural parameters choice depends on numerous factors

Heat

inappropriate for plastics and other sensitive items used for microbial control reliable, safe, relatively fasts, inexpensive, non-toxic can be used to sterilize or disinfect denatures proteins and unfolds them and some cannot go back to normal shape

Retort

industrial-sized autocalve

Bacteriostatic Preservatives

inhibits growth ex. glutamate and acids

Ozontation

kills everything, expensive, more effective than chlorination

Naked Viruses

lack lipid envelope more resistant to disinfectants

Dry Heat

less effective than moist heat longer times, higher temps 200 degrees Celsius for 90 minutes vs 121 degrees Celsius for 15 minutes hot air ovens oxidize cell parts and denature proteins

Mycel

lipids form layer and trap bacteria and dead material in soap

Bubbles

lots of ideation, lots of bacteria growing

Water Treatment Facilities

makes sure drinking water is free of pathogens chlorine

BSL-1

microbes not known to cause disease bunsen burner

Minimizing ______ in hospitals is very important

microbial population

Methods of Heat Treatment

moist and dry heat

High frequency has ______ energy than low frequency.

more

Heat Treatment

most common and reliable way to preserve food can alter flavor, appearance of products

High-Temperature-Short-Time (HTST)

most products method of pasteurization MILK: 72 DEGREES CELSIUS FOR 15S ICE CREAM: 82 DEGREES CELSIUS FOR 20S

Microwaves

not a good method of sterilization b/c they don't give uniform heat to whole thing form of radiation kill by generated heat, not directly heat food unevenly so cells can survive

BSL-4

organisms that don't have treatment Stanford and Baltimore death sentence

What can influence effectiveness of antimicrobial procedure?

pH and temperature even more effective at lower pH

What's more likely found in a hospital?

pathogens like feces, urine, respiratory droplets, and bodily secretions

Who's more susceptible to infection in hospitals?

patients, may undergo invasive procedures like surgery

FDA

regulates food preservation because risk of toxicity

Prions

relatively new concern and hard to kill protein that comes from goat and now comes in beef cannot be destroyed, only by incineration. Not by heat! self-growing polymerizing protein bind to protein from alpha to beta structure so they are all piled up like a block

Sterilization

removing all microorganisms free of microbes including endospores, bacteria, parasites and viruses, doesn't consider prions cannot be "sort of" sterile: it's either sterile or nonsterile

Pseudomonas Species

resistant to and can actually grow in some disinfectants most dangerous organisms can grow in air and water, without food absorbs food from air can cause infection in eye

Protozoan Cysts and Oocysts

resistant to disinfectants excreted inf eces causes diarrheal disease if ingested

Perishables

retain quality longer when contaminating microbes are destroyed, removed, inhibited keep them in a cold room

Filtration

retains bacteria KEEPS MICROBES WHILE LETTING THE SUSPENDING AIR OR FLUID TO PASS THRU SMALL HOLES filtration of fluids used extensively membrane filters and depth filters

BSL-3

room that's double contained

Microbiology Labs

routinely work with microbial cultures use rigorous methods of control must eliminate microbial contamination to experimental samples and environment careful treatment before and after aspetic techniques prevent contamination of samples, self, and lab

Pasteurization

shortly heating to get less spoilage organisms and destroys pathogens foods and inanimate objects only kills pathogenic bacteria JUICES ALSO PASTEURIZED high-temp-short-time and ultra-high-temp SIGNIFICANTLY REDUCES THE NUMBER OF HEAT-SENSITIVE MICROORGANISMS, INCLUDING SPOILAGE MICROBES AND PATHOGENS (EXCEPT SPOREFORMERS)

Physical Method

simple filtration or chemicals to disinfect or heat it

Microbial control methods depend on _____ and level of ______ needed.

situation, control

Membrane Filters

small pore size, .2 micrometers thin will remove everything - viruses and bacteria

Head is loaded with ______ and ____________

sporalitic bacteria and staph

BSL 2

spores and fungus

Uses of Autoclaving (Pressurized Steam)

sterilizes microbiological media, lab glassware, surgical instruments, and other items that steam can penetrate canning process renders foods commercially sterile

Autoclave

sterilizes using pressurized steam increased pressure raises temp and kills endospores sterilization typically at 121 degrees celsius and 15 psi in 15 min longer for bigger volumes flash sterilization at higher temp can be used

Facilities must keep ____ clean and relatively free of ______

surfaces, microbes

Depth Filters

thick porous filtration material, like cellulose bigger spores electrical charges trap cells get clogged easily

How does UV radiation have poor penetrating power?

thin films or covering can limit effect cannot kill microbes in solids or turbid liquids most glass and plastic block

Number of Microorganisms

time for heat and chemicals to kill affected by population size part of population dies in a certain amount of time bigger population = more time removing organisms by washing reduces time

Why do you have to sterilize instruments in hospitals?

to avoid introducing infection in deep tissues

Chlorine

traditionally used to disinfect water can react with natural chemicals/ORGANIC COMPOUNDS TO MAKE TOXIC CHLORINATED PRODUCTS some organism resistant to chemical disinfectants regulations require facilities to minimize DBPs and C. parvum in treated water attached to organic matter in water

T/F: Beneficial skin microbata is not adversely affected by regularly washing hands.

true

T/F: some materials cannot withstand heat treatment

true

Factors that Need to Be Considered When Choosing an Antimicrobial Procedure

type and number of microbes environmental conditions risk of infection composition of infected item

Biosafety Cabinet

under positive, high pressure hapa filter will trap all pathogens used for BSL-2

Disinfectants

used on inanimate objects and dead tissue aka biocides, germicides, bactericides

Antiseptics

used on living tissues

Commercial Canning Process

uses retort destroys Clostridium botulinum endospores important b/c endospores can germinate in canned foods cells grow in low-acid anaerobic conditions and make botulinum toxin canned food is commercially sterile

Hand Washing

washing and scrubbing with soaps and detergents achieves routing control most important stop in stopping spread of many infectious disease, very important in hospital

Mycobacterium Species

waxy cell walls makes it resistant to many chemical treatments coughing, sneezing makes bacteria go on walls

Color Indicatior

will turn black or colorless how we know it's clean