MBIOS 101 1st EditionExam # 2 Study Guide Lectures: 11 - 20Lecture 11 (February 12)1. How do we calculate how much bacteria have grown?a. Egg Salad Sandwich Examplei. The egg salad sandwich sits for 4 hours at 80 degrees Fii. Replicates once every 20 minutesiii. E. Coli has an inoculation of 10 cell organismsiv. Formula: Nt=No+2nv. To find n: n=60/20*4hrs=12vi. So Nt=10*2012=40,960 organisms vii. Is this safe to eat?viii. Most likely this is okay  most E. coli strains are okay and this in terms of bacterium is a decently small sample size2. Growth in environmentsa. Most environments have more than one type of bacteria growingb. Example Milk i. Primary Organisms in milk1. Streptococcus lactisa. Likes pH 7 (milk is pH 7)b. Loves lactose (a lot of lactose in milk)c. Because of this environment it thrives, overloads the system and starts to died. The waste products of streptococcus lactis makes the moreacidic2. Lactobacillusa. Likes a pH of 6.8b. So it waits to grow until streptococcus makes the milk more acidicc. Then it is grows, overloads the system and starts to grow d. The waste products make the milk even more acidic3. Yeasts and moldsa. Start to grow in the acidic environment – like pH of 4 b. Their waste products make the pH of the milk start to return to pH 7 4. Pseudomonas and spoilage organismsa. Likes pH of 7 b. Eats protein of milkc. This causes the milk to start curdling d. These organisms produce odor and so this gives old milk that nasty smelle. Their job is to decompose the milk f. Bacteria is important for this reason – to decompose materialLecture 12 (February 14)1. You are always being exposed to bacteriaa. In the kitchen – food made from bacteria and other bacteria grow in foodb. Bathroom- toothbrush, hairbrush, deodorant, toilet, etc. c. Utility room – litter boxes, stuff shoes track in d. Other places – handrails, office (keyboards, coffee cup,etc.)e. Gym – the equipmentf. Soda machinesg. Conference tablesh. Air conditioner i. Gas pumps j. Many more k. NOTE: Hydrogen peroxide has a ton of benefits – whitens teeth, cleans toothbrush, blood stains on white clothes, eliminates bad odors etci. Vinegar – 1. Calm upset stomach2. Leg cramps3. Cools a sunburn 4. Removes corns and callouses 5. Many more2. Microbial Control:a. History i. Ignaz Semmelweis 18471. Child birth fever- need to wash hands, people would go from doing an autopsy to directly checking if the women were dialted enough 2. Chlorine wash – the disinfectant in watera. Asked one half of the room to wash their handsb. The half of the room with hand washing had no problem with child birth feverii. Robert Lister (Listerine company) 18671. Antisepsis during the surgery a. Patient death from surgeryb. Got much better c. Because of this better protection – aprons, gloves, masks, etc. 2. Now the Listerineb. Where do you find organisms?i. Daily Life – your home, hospital, medical location, dental, nursing homes, etc.ii. Food production1. Water treatment 2. Micro labsa. Research b. Diagnostic3. Vet animals hospitals c. Terms to knowi. _______cidal: to kill, this means is kills what ever (viracidal- kills viruses)ii. _______static: to inhibit, this means to slow down (the fridge doesn’t kill the organisms but it slows down the growth)iii. Sterilization: process that destroys or removes all viable microorganisms (including viruses)1. There is no growth2. Used on inanimate objects – used on syringes, packaged food, etc.3. Agents: a. Heat (autoclave)b. Sterilants (Chemical agents capable of killing everything)iv. Disinfection: (1) physical processes or a chemical agent to destroy vegetative pathogens but not bacterial endospores, (2) removes harmful products of microorganisms (toxins) from material 1. Used on inanimate objects2. Common uses: boiling, 5% bleach3. Used on: tables, etc. 4. Kills organisms in vegetative state(growing) v. Sanitization/decontamination: cleansing technique that mechanically removes microorganisms as well as other debris to reduce contamination to safe levels 1. Used on areas when someone threw up, etc2. Agents: soap, detergents commercial dishwashers vi. Antiseptic/degermation: reduce number of microbes on the human skin1. Agent – alcohol Lecture 13 (February 19)1. Microbial Control Continued 2. Factors to choose control method?a. Type of microbes i. Bacteriaii. Virusiii. Parasiteiv. Mold/fungiv. Algaevi. Arthopods b. Range of Sensitive to Resistant i. Least resistant (most sensitive): enveloped virusesii. Most gram positive organsimsiii. Non-enveloped viruses iv. Fungi and fungal sporesv. Most Gram negative bacteriavi. Protozoan cystsvii. Staphylococcus and Pseudomonas viii. Mycobacteriumix. Bacterial endospores x. Most resistant (least sensitive): prions c. Concentration of microbes—contacti. High numbers and low numbers: 10  100,000  billionii. Some that die are used to protect the other living bacteriaiii. Slime layers and biofilms  how long does it take for the cleaner to reachthem? d. “Their” environmental conditionsi. pH, temperature, salt concentration, oxygen, contact time with cleanerii. Ex. Bleach1. TB – @ 50º C contact time has to be at 150 sec, @55ºC contact time for 60 sec iii. You must consider their environment in order to be able to kill or grow them e. Organicsi. What is the area to be cleaned?1. Is there blood/vomit (a lot of protein)?2. Is it feces/ dirt/grease/grime?3. Is it a body secretion?ii. How long does it take to denature the proteins in it?iii. Water  Spring Run Off  dirt, etc. 1. This is carried down2. Along with sewage treatment plants, dead animals, etc3. How do you filter a flood?f. Type of surface i. Non-living:1. Rough/smooth2. Examples: concrete, wood, plastic, metal, clothes, objects, etc. 3. Special considerations: “pet friendly motels”—Sudsy ammonia takes out the smell of urine ii. Living:1. Skin 2. Teeth3. Gums4. Body parts 3. Compatibility with material to be treateda. Will it melt?b. Will it break? (cold)c. Will it be damaged: metal, plastic, rubberi. Corrosive cleaners (bleach) – should not be usedd. Notes: Plastic water bottles (Dr. Pat Hunt – WSU faculty member) and animal cages i. The cleaner caused etching plasticii. Plastic released fumesiii. Tumors increased significantly in miceiv. That’s why there were only metal water bottles for a while but now there are plastic water bottles that don’t release these fumes4. Residue a. Is there a film left?i. Safe?ii. Toxic?iii.