Microbiology Exam 2 3/29/22
mechanical, chemical, and cellular defenses protect the GI tract from ___
pathogen colonization
cephalosporins and carbapenems are not ___
penicillins
4 main lower respiratory tract diseases
pertussis (whooping cough), tuberculosis, pneumonia, Legionnaire's Disease
4 main diseases that affect upper respiratory tract
pharyngitis, diphtheria, meningitis, otitis media
how do cold temperatures affect microbial growth?
slows microbial growth
elevated ___ is a common physical control method for microbial growth
temperature
TB treatment
· Exclusive treatment for TB: Isoniazid (takes out the cell wall) o Rifampin can also be used (not only for TB, but one you can use)
TB, if no treatment:
dead within two years, infection spreads beyond lungs (disseminated TB)
define the antimicrobial spectrum
drugs have a range of pathogens on which they will work
bacteria: hemorrhagic colitis
enterohemorrhagic E. coli (EHEC)
define selective toxicity
. We want the drug to attack the bacteria and leave our cells untouched. We want to know special features of each so we can decide how to attack.
catarrhal stage of whooping cough
Catarrh is an excessive buildup of mucous in a cavity.
what are the 3 stages of whooping cough?
Catarrhal stage Paroxysmal stage Convalescent stage
main mode of transmission of toxoplasma gondii
Cats: they will shed cyst stage through feces (fecal oocytes)
which parasitic protists causes malaria?
Plasmodium
bacteria: malaria
Plasmodium: 4 types -P. falciparum -P. vivax -P. ovale -P. malariae
air can be filtered using ___
a high-efficiency particulate air (HEPA) filter
skin wound infections can be the result of ___
a resident microbiome
hydrogen peroxide is beneficial in killing ___
anaerobic bacteria
2 main arthropod borne diseases
-lyme disease -rickettsial diseases (Rocky Mountain spotted fever)
why are amoebas unique?
- have unique means of locomotion with pseudopods
boiling water sterilization
-100 degrees for 2 hours in boiling water -boil water for 2 hours straight to kill spores. -Not a great method. Will reduce infectious microorganisms, but some hearty microbes could stay after small amount of boiling
there are over ___ species of protists. some are ___
-200,000 -human parasites
bacterial ribosomes makeup
-70 S total (50S/30S)
eukaryotic ribosomes makeup
-80S total (60S/40S)
which antibacterial agents work to inhibit nucleic acid synthesis?
-DNA replication (quinolones) -RNA transcription (rifampin)
two separate categories of organs in digestive system
-GI tract -accessory digestive organs (ex. gall bladder)
3 types of pneumonia
-Healthcare acquired pneumonia (HAP) -community acquired pneumonia -atypical pneumonia
4 main types of meningitis
-acute bacterial -meningococcal -pneumococcal -Haemophilus
2 types of chemical sterilants
-aldehydes -sterilizing gases
which antibacterial agents work to inhibit translation?
-aminoglycosides -chloramphenicol -tetracyclines -macrolides -clindamycin -streptogramins -oxazolidinones
antibiotic resistance involves different protection strategies: what are the 5?
-antibiotic hydrolysis -antibiotic modification -membrane modification/efflux -target modification -metabolic pathway alteration
3 main types of antimicrobial drugs
-antibiotics -semisynthetic drugs -synthetic drugs
3 main chemical control methods (depend on object to be treated)
-antiseptics, disinfectants, degerming
___ is used in BCG immunization, but ___
-attenuated M. bovis -has limited effectiveness in adults
which microbes are susceptible to chemical sterilant?
-bacterial endospores (bacillus, clostridium)
what do we target that results in death of microbe?
-cell wall/membrane -denaturing DNA/proteins
2 other beta-lactam antibiotics
-cephalosporins -carbapenems
phenol and phenolic compounds ___
-denature cell membrane proteins -intermediate level
define antibiotics and where they're found. Give example.
-derived from the metabolism of living organisms. o Fleming observed Penicillium mold produces a substance (penicillin) that kills Gram(+) bacteria. o Found in nature - from bacteria, fungi, and have antimicrobial properties
define hot air ovens
-do not penetrate materials easily, but long-term exposure to high temperatures can be used for sterilization. (heated air) o 160ºC for 2 hours will sterilize most objects. o Ability of dry heat to penetrate through objects takes a long time o We would need high temperatures to sterilize with oven o You'll also need a cool down period o Plastics, rubbers can't go in there
What are the non-beta lactam cell wall inhibitors?
-glycopeptide antibiotics like vancomysin -no ring (just a sugar and a protein)
2 main types of parasites
-helminths (worms) -protists
describe how HEPA filters work
-help filter out air, there is still air flow - air flow goes in grates, recycled through filters found inside (air behind working glass is then sterile)
what are the 3 methods of pasteurization?
-holding/batch method -flash pasteurization -ultra high temp sterilization (UHT)
define flash pasteurization
-increases temperature to decrease time -microbes would be killed at 72 degrees for 15 seconds -shelf life: weeks
define endotoxins
-lipid portions of lipopolysaccharides (LPSs) that are part of outer membrane of cell wall of gram negative bacteria. -liberated when bacteria die and cell wall breaks apart
skin diseases cased by staphylococcus aureus/toxin associated S. aureus contact diseases
-localized skin infections -impetigo -scalded skin syndrome -toxic shock syndrome (TSS)
define degerming
-mechanically removing organisms from an object's surface -ex. rubbing hand sanitizer between hands (uses mechanical force to help remove microbes) -ex. lysol wipe to rub down counter (disinfecting and degerming at the same time) -ex. hand washing
3 types of sterilization
-microbicidals -bactericidals -fungicidals
3 types of disinfection
-microbiostatics -bacteriostatics -fungistatics
killing a microbe via targeting cellular structures
-most targeted: the bacterial cell envelope -cell wall damage -phospholipids/cell membrane proteins
is milk with a short shelf life in the fridge sterile?
-no -bacteria still present in milk
which microbes are susceptible to high level disinfectant?
-nonenveloped viruses (polio) -protist cysts (entamoeba) -mycobacterial species (tuberculosis)
define UHT
-not called pasteurization, but method is the same -liquid passed through heating element -microbes would be killed at 140 degrees in 3 seconds -shelf life: months, shelf stable
which antibacterial agents work to block cell wall synthesis?
-penicillins -cephalosporins -vancomycin -bacitracin -carbapenems
what happens at temperatures above the growth range?
-proteins and nucleic acids are destroyed (overheating interferes wit proteins ability to be folded) -water is removed (affects the cell membrane, as it is full of phospholipids and lipids are full of fluid) -- fluidity is increased and membrane is destroyed
define exotoxins
-proteins produced inside pathogenic bacteria (most commonly gram positive), as part of their growth and metabolism -secreted or released into surrounding medium following lysis
define holding/batch method of pasteurization
-refrigeration required after -any bacteria still present that could make you sick would be killed at 63 degrees Celsius in 30 minutes -shelf life: days
what are the two major ways to kill a microbe?
-some agents act in one of the two, and some can do both -targeting cellular structures or interfering with metabolic activities
bacteria: otitis media
-streptococcus pneumoniae -haemophilus influenzae -moraxella catarrhalis
3 types of synthetic antibacterial agents
-sulfonamides -quinolones -isoniazid
When is aseptic technique used?
-surgical settings, prevents contamination
2 main types of soil borne bacterial infections
-tetanus -gas gangrene
___ are the vectors of two different diseases:
-ticks -Lyme disease, rickettsial disease
define pressurized steam
-type of moist heat · used in an autoclave as a more dependable way to sterilize a variety of objects. (instruments, glass, liquids) o Pressure of 15 psi at 121ºC for 15-30 minutes, depending on the object being sterilized, will kill bacteria. -moisture and pressure added into heat -gives enhanced penetration of heat to go through objects -anything that disintegrates in water can't go through
5 types of invasive gastroenteritis
-typhoid fever -salmonellosis -hemorrhagic colitis -listeriosis -peptic ulcer disease
define antiseptics
-used to destroy pathogens (reduce number of microbes) on living tissue -ex. alcohol swab before injection
define pasteurization
-uses moist heat -reduces bacterial populations in food and drink. (reduce number of pathogenic microbes in liquids meant for human consumption - ex. Milk, juice)
which microbes are susceptible to low level disinfectant (and above)? These are also susceptible to ___
-vegetative bacterial genera (staphylococcus, pseudomonas) -enveloped viruses (Flu, HIV) boiling water
oven sterilization
160 degrees for 2 hours in the oven
___ people are infected with TB globally
2 billion
define liquid filtration
As fluid passes through a membrane filter, organisms above a certain size threshold are trapped in the pores.
bacteria: Lyme disease
Borrelia burgdorferi
define surgical skin wounds
Can introduce indigenous microbes to tissues and cause an infection.
bacteria: gas gangrene
Clostridium perfringens
bacteria: tetanus
Clostridium tetani
how do bacteria in soil cause human infection?
Could ingest soil on vegetables or through spores (via ingestion, open wound), manure/animals going through soil
E. coli makeup
E. coli are gram-negative, so they have gram-negative cell walls § They have LPS (endotoxin) § Could have capsule and flagella § E. coli O157 in cell wall (O antigen), Flagella have 7 (H antigen)
bacteria: Traveler's Diarrhea
Escherichia coli
define chronic wounds
From predisposing conditions such as peripheral vascular diseases, result of lack of blood flow to body tissues, and are generally polymicrobial.
define impetigo
Highly contagious blisters. (golden crusty lesions on the face near mouth, although you could get it anywhere) - common in children
Why is the cell wall a good target for antibiotics?
Human cells don't have a cell wall, so a cell wall inhibitor won't affect our cells.
high levels of a certain endotoxin ___ is bad
Lipid A
what is the most commonly reported arthropod borne illness in the US?
Lyme disease
___ is affecting which antibiotics are used to treat TB
Multidrug-resistant Mycobacterium tuberculosis (MDR-TB)
mostly widely used antibiotic
Penicillin
what was the first beta-lactam drug?
Penicillin G
bacteria: acne
Propionibacterium acnes
Bacteria: Rocky Mountain spotted fever
Rickettsia rickettsii
what antibiotic inhibits nucleic acid synthesis?
Rifampin
define commercial sterilization
The process of killing all pathogens in a product, particularly in the food supply.
Arthropods a. what are they b. when a living organism, such as an arthropod, transmits disease agents, it is known as ___ c. arthropod-borne diseases occur primarily ___ d. often characterized by ___ e. general mechanism
a. Arthropods have jointed appendages and segmented bodies (ex. Insects- mosquitos, fleas, lice, ticks) b. a vector of disease. c. in the bloodstream d. high fever and a body rash. e. These diseases are spread through bite of arthropod, goes into bloodstream (COULD also be through just surface spreading, not a bite) - the bacteria lives inside the guts/salivary gland of the vector
Legionnaire's disease a. caused by b. disease development c. this is why you have to ___ d. ___ may develop
a. Atypical. Causative agent is Legionella pneumophila. b. It lives where water collects and becomes airborne in the wind (or ventilation system). - sick if you breathe in contaminated water aerosolized droplets o Named after American legion · Disease develops within a week of inhalation of contaminated droplets. c. run lines in dental offices d. Necrotizing pneumonia
Antibiotic Hydrolysis a. defintion b. example c. where does the enzyme come from?
a. Bacteria is producing enzyme that can degrade certain category of antibiotics o Enzyme is chewing up the antibiotic (antibiotic is chemically changed, inactivated, disintegrated) b. Ex. Staph, producing beta lactamase enzymes - bacteria with this will degrade beta lactam antibiotics c. Gene encodes for this enzyme, bacteria could get this gene and make the enzyme, leads to resistance
Chloramphenicol a. effect on subunit b. used to treat ___ c. adverse effects
a. Broad-spectrum antibiotic that binds 50S subunit and blocks peptide bond formation between amino acids b. typhoid, epidemic typhus, and Rocky Mountain spotted fever. c. Severe side effects, including aplastic anemia. o Quite toxic, used for things we don't have much else for
Aldehydes a. how do they work b. example
a. Cause cross-linking that inactivates proteins and nucleic acids; o Put in tissue you want to preserve to prevent invading bacteria from taking over b. formaldehyde
Gas Gangrene a. cause b. mechanism
a. Clostridium perfringens; endospores present in environment (opportunists - if they make their way into a wound in the skin, endospore can germinate in low oxygen, grows and divides) - makes lots of toxins and enzymes o Attacks areas with lower blood flow b. Massive tissue damage/death due to a group of toxins and hydrolytic enzymes. § More dead tissue = more favorable for this bacteria, bacteria can then increase its numbers o Dead muscle tissue blocks blood flow, causing gangrene and gas below the skin. § As bacteria is growing, it's actively metabolizing and releasing byproducts like fermentation gases (bubbling noises under skin when severe) § Discoloration due to necrosis
Tetanus a. caused by b. symptoms c. treatment/immunization
a. Clostridium tetani endospores enter deep puncture wounds and become vegetative. o Vegetative cells produce a neurotoxin called tetanospasmin that blocks the inhibition of muscle contractions, leading to muscle spasms. b. fixed smile (risus sardonicus), lockjaw (trismus), and opisthotonos (arching of the back). c. Treat with (antibiotics and antitoxins) § Untreated tetanus causes violent death via asphyxiation. § Kill the bacteria and neutralize the toxin d. Immunization DTaP vaccine and boosters.
Tetanus a. exposure b. mechanism c. neurotoxin
a. Do not get infected through ingestion - should be concerned if any of the endospores gain access to bloodstream via puncture wound to skin b. Wound that is created results in tissue death - area becomes necrotic § C. tetani are anaerobic organisms - obligate anaerobes § In order for them to survive is by forming an endospore - resistant to all environmental conditions § Need anaerobic environment if we want actively growing clostridium § The necrotic tissue creates that low oxygen environment for endospore to germinate - develops into infection of actively dividing C. tetani cells in wound c. When those cells are actively dividing, they create exotoxin (damage being caused by very potent exotoxin) - specifically, a neurotoxin (exotoxin that affects nervous system) Neurotoxin leads to spasms, contractions, paralysis
Hemorrhagic Colitis a. caused by b. most commonly identified EHEC c. what is it? d. a life threatening complication is: e. treatment f. produce can be ___ g. complication
a. Enterohemorrhagic E. coli (EHEC) strains cause disease by producing Shiga-like toxin, which inflames the intestinal epithelium and triggers gastroenteritis. § Thought that at some point, harmless strand of E. coli encountered Shigella, then through horizonal gene transfer, there was transfer of Shigellatoxin into strain of E. Coli. Now we have new virulent E. coli strain. b. E. coli O157:H7. c. the inflammatory response to the Shiga-like toxin, characterized by abdominal cramps, mild fever, and bloody diarrhea. d. hemolytic-uremic syndrome (HUS). e. No antibiotics can be used; supportive care and fluid-replacement is necessary. f. recalled g. clotting occurring in bloodstream - kidney is trying to filter them out - start passing through and getting trapped in there § Can result in impaired renal function - leads to kidney failure § Have to go on dialysis until you solve this
Vancomycin a. effective against ___ b. use c. what has now emerged?
a. Gram-positive bacteria such as staphylococci (Narrow-spectrum). b. Used as a drug of last resort, especially to treat MRSA. § Use if beta-lactam drugs aren't working and it's gram-positive c. Vancomycin-resistant Staphylococcus aureus (VRSA) strains
Streptococcus pyogenes a. ___ includes S. pyogenes b. pathogenicity proceeds by: c. transmission occurs by ___ d. One serious streptococcal soft tissue infection is:
a. Group A strep (GAS) b. attaching to cells and c. direct contact with the mucus from the nose or throat of infected individuals or through contact with infected wounds on the skin. d. necrotizing fasciitis
Haemophilus Meningitis a. cause b. prevention
a. Haemophilus influenzae type b (Hib) b. Prevented now in the United States with the Hib vaccine.
Malaria a. ___ is responsible for symptoms of malaria b. early signs c. cycle d. if untreated
a. Intraerythrocyte cycle b. shivers, then high fever, sweating, headache, delirium for several hours. c. The cycle repeats every 2-3 days (depending on the species) d. Severe anemia (low RBC count), organ failure, hemorrhages can be fatal when untreated.
Penicllins a. produced by ___ (natural) b. include a ___ c. active against ___ d. interfere with ___
a. fungus Penicillium notatum b. beta-lactam ring (Beta lactam must be present for beta lactam drug - integrity of ring is necessary for function of drug) c. many Gram + and some Gram - d. cell wall synthesis in rapidly growing cells, causing the cell to burst (bactericidal).
Listeriosis a. caused by ___ b. how contracted c. primarily affects d. treatment e. symptoms? f. starts in ___
a. Listeria monocytogenes. b. via ingestion of fecally contaminated food, water, or milk. § The pathogen can survive refrigeration and freezing. c. pregnant women, newborns, the elderly, and the immunocompromised, causing a form of meningitis. § Bacteria can reach fetus's brain and can kill them/cause complications § Pregnant women must avoid anything unpasteurized, deli meat, and fruits/vegetables must be washed thoroughly d. Antibiotic treatment must begin immediately following diagnosis. e. Most are fine when you ingest, could have no signs/symptoms (healthy immune systems) f. GI tract, can make its way to the brain - can cause bacterial meningitis
Helminths (Worms) a. cells b. fall within: c. 3 types
a. Multicellular b. animal kingdom c. · Trematodes (Flukes) - could live in bloodstream, liver · Cestodes (Tapeworms) · Nematodes (Roundworms)
Tuberculosis a. caused by b. as few as ___ can initiate an infection c. clinical TB develops within ___ d. staining
a. Mycobacterium tuberculosis enters the respiratory tract in small aerosolized droplets. b. 10 M. tuberculosis bacilli c. 3 months and can be transmitted to others d. Cannot be accurately gram-stained (use acid-fast stain)
Atypical Pneumonia a. cause b. mostly affects ___ c. epidemics tend to occur in ___ d. symptoms e. bacteria make up f. treatment
a. Mycoplasma pneumoniae causes primary atypical pneumonia, often called walking pneumonia. b. children and young adults, ages 6 to 20. c. overcrowded conditions, such as military bases, schools, and college dorms. d. not typical (dry cough) e. Has no well-designed shape - pleomorphic o M. pneumoniae has no cell wall. f. Cell wall inhibitors won't help, go to is protein translation inhibitor to treat this (Z-Pack)
Rocky Mountain Spotted Fever a. caused by b. limited to Rocky Mountains? c. symptoms d. mechanism e. why is it so dangerous?
a. Rickettsia rickettsii, which is transmitted by hard ticks. (Gram negative bacteria) - transfer of bacteria from infected tick, but species of tick is different b. no c. high fever, headaches, and maculopapular skin rash. d. Development of widespread rash on body within a few days of being bitten o Bacteria is infecting endothelial cells (which line vasculature in body) so everywhere you see rash, that's damaged blood vessel o Looks like little red spots - direct result of bacteria living inside endothelial cells § Lives INSIDE cells - intracellular bacteria e. Very dangerous infection - widespread damage to circulatory system o You can die within a week once you develop signs and symptoms if no treatment
Salmonellosis a. caused by b. transmitted by c. ___ cases each year globally d. immune cells e. likely to see ___ f. travel g. could persist for ___
a. Salmonella enterica serotypes are often found in unpasteurized milk or poultry products. b. fecal-oral route or by chickens, turkeys, eggs, and pet turtles. c. 94 million d. Intestinal ulceration less severe than typhoid, and immune cells can kill the bacteria. e. blood in diarrhea f. Can't break through intestines, more confined - doesn't travel through body g. 7-10 days
Protists a. cells b. pili? c. 4 types
a. Single-celled b. NOT bacteria, so no pili c. · Amoebas · Plasmodium (Malaria) · Toxoplasma · Giardia
Skin a. function b. microbiota c. epidermis: d. subcutaneous layers:
a. Skin protects underlying tissues from microbial colonization. b. Has a rich microbiota - microbiota considered part of innate immune system; can help prevent invaders on skin · Microbiome varies. There are dryer/oily parts of skin with different types of bacteria. · The microbiome of the skin varies by site o Sebaceous sites o Moist sites o Dry sites c. outer layer; these cells are essentially dead and will slough off (innate defense mechanism) d. vasculature
Localized Skin Infections a. caused by ___ b. what are the 3 types/levels? c. treatment: d. differences in diseases is ___
a. Staphylococcus aureus can create localized skin infections b. Folliculitis (on hair shaft, little bump) o Boils (on hair base, painful - deeper you go, the more it hurts) o Carbuncles (multiple infected hair follicles in close vicinity, pus formation, may require debridement of area - definitely treat with antibiotics) c. antibiotics and debridement. d. strain dependent
Community acquired pneumonia a. caused by b. acquired through: c. can involve (3): d. vaccines available for ___
a. Streptococcus pneumoniae causes pneumococcal pneumonia. b. aerosolized droplets or contact. c. Pneumococcal pneumonia can involve: § An entire lung lobe (lobar pneumonia). § Both lungs (double pneumonia). § Patches in the respiratory passageways (bronchopneumonia). d. children and elderly.
Clostridium difficile Infection (CDI) a. treatment options
a. Suspend antibiotics (if you developed this from taking broad-spectrum antibiotics for something else) § Treat with narrow-spectrum antibiotics to prevent widespread disruption of bacteria in body (vancomycin) - could take several rounds and C. difficile may not go away § Fecal transplant can cure 90% of patients with long-term C. difficile infections. · Looking for good intestinal bacteria in feces
Meningococcal Meningitis a. what is it? b. caused by c. symptoms d. vaccine? e. death
a. The most dangerous form of acute bacterial meningitis o It is the major cause of disease and mortality in infants globally. b. Neisseria meningitidis c. Rash that turns bruise-like (dark purple) · Can develop septicemia - if toxin is being shed into bloodstream, you develop characteristic rash · Underlying blood vessels are being damaged throughout body d. Vaccine to some serotypes available o CDC recommends meningococcal conjugate vaccines for first-year college students living in residence halls. e. Can die within a day upon developing signs/symptoms
Toxoplasmosis a. caused by b. affects c. pregnancy exposure d. not pregnant exposure
a. Toxoplasma gondii (widespread parasite) b. half the world's population. c. If exposed during pregnancy, mother might be fine, but could cause congenital infection in fetus d. Not pregnant? Usually nothing happens. Many people walk around and have no idea that they have it
Plasmodium a. what is it b. causes: c. transmitted by d. what are the 4 species of Plasmodium that cause malaria and which is most serious/virulent
a. a deadly blood parasite. b. Malaria affects 300-500 million people. c. Anopheles mosquito vector. d. P. falciparum, P. vivax, P. ovale, P. malariae. o Most serious and virulent bacteria is P. falciparum (highest death rate)
Streptococcal Pharyngitis a. otherwise known as b. caused by
a. strep throat b. Streptococcus pyogenes enters the upper respiratory tract through respiratory droplets.
Diphtheria a. what is it b. caused by c. mechanism d. death e. treatment
a. a local infection of the mucous membranes of the nasopharynx b. Corynebacterium diphtheriae. (pharynx or nasal passages) o respiratory droplet transmission. c. The bacteria produce an exotoxin that inhibits translation in host cells. § This results in the accumulation of a pseudomembrane on the tonsils or pharynx § Cytotoxin: cell killer - inhibits protein translation in surrounding cells (respiratory epithelial cells) § End result: accumulation in nasopharynx, dead respiratory epithelial cells, infiltration of our immune cells that are trying to help (White blood cell infiltrates), fibrin being laid down (part of inflammatory response) - pseudomembrane starts to be formed from a combo of everything d. Can be life threatening if pseudomembrane forms and blocks trachea - die by suffocating (Swelling of the epiglottis can block the trachea.) e. Treatment requires antibiotics and antitoxins. § Injection of diphtheria toxoid is used for vaccination (DTaP). § Pseudomembrane must be surgically removed, kill bacteria with antibiotics, stop exotoxin from working and killing cells (antitoxins neutralize toxin as well)
Acute Bacterial Meningitis a. begins when ___ b. spread through ___ c. symptoms ___ d. untreated acute cases can result in ___ e. test:
a. a localized infection invades the blood, then the meninges around the brain and spinal cord.; Gateway to meninges begins with upper respiratory tract · Bacteria make their way to meninges (layers that cover CNS) b. respiratory secretions c. high fever, headache, nausea, vomiting, and stiff neck. d. death within hours e. put your chin to your chest
Botulism a. caused by b. prevented by c. common sources
a. a potentially deadly neurotoxin released by the bacilli of Clostridium botulinum, the spores of which are often ingested with food. (one of the few bacterial species that can form endospores) - tough to kill, very resistant b. heating spore-contaminated foods: c. home-canned foods, salami/sausage, and honey.
Pneumococcal Meningitis a. what is it b. cause c. vaccine?
a. about 30% of meningitis cases, and has a high mortality rate. --Bacteria making it to your meninges, and it shouldn't be there. S. pneumonia is part of respiratory microbiota, can cause many things with overgrowth. b. Streptococcus pneumoniae c. Vaccines available: § Prevnar 13 (first 13 it protects against) § Pneumovax (get this when you're older)
Rickettsial Diseases a. spread by ___ b. involve a characteristic ___ c. treated effectively with ___ d. main associated disease
a. anthropods b. rash c. doxycycline or chloramphenicol. d. Rocky Mountain spotted fever
Aminoglycosides a. effect on subunit b. example c. when prescribed
a. attach irreversibly to small 30S ribosome, blocking translation (bactericidal); cause misreading of genetic code on mRNA b. streptomycin c. Only prescribed modernly as a co-drug for treatment of antibiotic-susceptible cases of tuberculosis.
Lincosamides a. effect on subunit b. example
a. binds to 50S subunit and prevents chain elongation b. Clindamycin is a semisynthetic drug used against penicillin-resistant bacteria.
Macrolides a. effect on subunit b. 2 examples
a. binds to 50S subunit and prevents chain elongation b. erythromycin (used against gram + bacteria); azithromycin (Zithromax/Z-pack)
Typhoid Fever a. involves ___ b. it is __ resistant, meaning ___ c. has ability to ___ d. mechanism e. can persist in ___ (and we'll see what system)
a. blood infection caused by Salmonella enterica serotype Typhi (S. Typhi). b. acid; it passes through the stomach to the small intestine, where it causes ulcers, bleeding, and pain. c. evade immune system d. Acts on intestinal wall and causes ulcerations (can pass through intestinal wall. Macrophages are first cell that Typhi will come into contact with. Macrophages engulf the salmonella but can't kill it. It survives inside macrophages. Macrophages are circulating throughout body in bloodstream. Now mixed in with white blood cells) o Can live inside macrophages and be transported in the bloodstream e. gall bladder
Tetracycline a. effect on subunit b. adverse effect c. used to manage ___ d. examples and what they treat e. effect on calcium
a. broad-spectrum antibiotics that block the attachment of tRNA to the small 30S ribosome subunit. b. They can destroy intestinal microbiota and cause staining of the teeth and stunted bones. c. periodontal disease (broad - can treat variety of infections) d. doxycycline (Lyme disease); minocycline (acne) e. Tetracycline is a chelator of calcium especially (calcium chelation can have skeletal effect on fetus and effects on teeth) - can't be used in kids under 8 or pregnant women; causes permanent staining (from inside out)
Cholera a. what is it b. caused by ___ c. outbreaks where
a. can involve enormous fluid loss through diarrhea. b. Vibrio cholerae c. in places with poor sanitation (natural disasters - breakdown in water sanitization)
Phenol a. phenol is ___ b. who was the first to use phenol as a disinfectant? c. we have phenol derivatives because ___ d. derivatives have:
a. caustic. b. Lister; (gold standard for years) c. straight phenol will burn d. o Greater germicidal activity. o Lower toxicity than phenol.
Acne a. definition b. mechanism c. treatment d. can you have the bacteria but not have acne?
a. chronic inflammation experienced by 85% of adolescents and young adults and is caused by excess sebum and Propionibacterium acnes. b. Hair follicles become swollen with sebum and keratinocytes. Open comedones are blackheads, whereas closed comedones are whiteheads. c. mild soap and benzoyl peroxide, severe cases may require antibiotics. d. yes
Alcohols a. how do they work b. what level c. effective against ___ d. used in many ___
a. denature proteins and disrupt membranes by lipid dissolution o Reliant on having right concentration for it to work o Can only work if it is in the presence of water b. intermediate c. vegetative cells, but not spores d. hand sanitizers
Hydrogen Peroxide a. what level b. how does it work?
a. high b. damages cellular components o Catalase in wounded tissue transforms it to oxygen and water. o The oxygen is effective against anaerobic bacteria. o Oxygen radicals also form o Oxygen converts into free radicals, oxygen free radicals can cause damage to membranes/proteins unless there are enzymes in the cell that can neutralize these
Escherichia coli Diarrhea a. where is E. coli found b. ETEC c. what is this also called d. get from ___ e. infection/antibiotics
a. human intestine, but certain serotypes are pathogenic. o Enterotoxigenic E. coli (ETEC) penetrate the intestinal epithelium and produce an enterotoxin that causes gastroenteritis. c. "Travelers Diarrhea" transmission occurs through the fecal-oral route and lasts 3-7 days. d. eating contaminated food e. Infection - will take some time to establish itself in the body § 2-3 days after eating contaminated food § Infection - do we want antibiotics? You won't be sent home with antibiotics; this infection will run its course via the diarrhea. You'll overcome this on your own.
Heavy Metals a. how do they work? b. what level? c. ___ are reactive with proteins d. thimerosal e. how does copper piping help?
a. interfere with microbial metabolism o They disrupt cellular metabolism by inactivating enzymes and denaturing structural proteins o Don't kill, but don't allowing further growth b. low c. Mercury, copper, and silver d. was used in vaccines as preservative (mercury compound - concern for neurological effects) e. helps ward off microbial growth
Rifampin a. effect b. effective against c. bacteriostatic or bacteriocidal
a. interferes with RNA synthesis by binding to the bacterial RNA polymerase; interferes with transcription b. tuberculosis, leprosy, and meningitis. c. Bacteriocidal
Liquid Filtration a. special type of ___ b. has to be designed with ___ c. liquid that passes through membrane should be ___ d. all ___ should not be able to pass through e. when is this useful?
a. membrane (consider pore size) b. specific pore size that will essentially allow for liquid to pass through membrane, but pores will be small enough that microbes remain trapped on other side of membrane c. microbe free d. bacteria e. useful if you have a solution that has to be microbe free but can't stand other ways of getting rid of them o i.e. heat intolerant liquid, this is a way to sterilize without heating
Antibiotic Modification a. mechanism
a. o Antibiotic administered; a molecule produced by bacteria (like protein) that binds up the antibiotic o Because it's bound to a "modifier," it can't get to the target molecule o Antibiotic can't get to target o Bacteria probably has a gene that encodes for this modifier
Membrane Modification/Efflux a. mechanism b. common mechanism in ___
a. o Antibiotic gets inside, but is then pumped back out o On the membrane of the bacteria, there is an efflux pump embedded in membrane o This pumps the antibiotic back outside o Prevents antibiotic from getting to its target b. cancer cells
Clostridium difficile Infection (CDI) a. describe clostridium difficile b. associated diarrhea
a. o Endospore former, this can be found in anyone's GI tract (could carry it around without developing sickness) - bacteria live in your GI tract, then move out via feces, gets exposed to oxygen § Clostridium is an anaerobe § When exposed to oxygen in environment, forms more endospores § You could ingest someone else's endospores § When you ingest and it goes to GI tract, oxygen goes down, bacteria start to grow again b. o Diarrhea associated with antibiotic use (dysbiosis). (occurs when this dangerous bacteria is increasing in numbers in GI tract) - easy for those with weakened immune systems to pick up the infection. As it grows and divides, it secretes toxins, damages lining of GI tract
Metabolic Pathway Alteration a. ex b. mechanism
a. o Ex. Sulfa drugs (take advantage of folic acid in our diet) b. o Interact with important enzyme in pathway so substrate can no longer bind o Solution: alternate pathway to get end-product
Target Modification a. mechanism
a. o Nothing happens to antibiotic, it's still free o Nothing chews it up or binds with it o We are now messing with its target molecule (Changes) o Cannot bind to target molecule anymore, won't work
Healthcare acquired pneumonia a. affects ___ b. what are the 3 types of bacteria involved c. some bacteria present ___
a. patients who have been on respiratory devices b. Staphylococcus aureus; Klebsiella pneumoniae; Pseudomonas aeruginosa c. only in healthcare setting
Peptic Ulcer Disease a. can be spread from ___ b. can survive in ___ c. caused by ___ d. mechanism e. treatment
a. person to person b. stomach acid c. Helicobacter pylori causes gastric ulcers and is likely transmitted via contaminated food or water § Secretes enzymes that neutralize pH of stomach d. The ammonia and an H. pylori cytotoxin destroy mucous-secreting cells, creating an ulcer. o Ulcers are very painful, causes weight loss o Long-term process can cause damage (stomach cancer) from extensively long inflammation e. Treated with antibiotics, combination therapy
Clostridium difficile Infection (CDI) a. one toxin can cause ___ b. explain how C. diff can be awoken
a. pseudomembranous colitis, which can lead to toxic megacolon. (signs and symptoms: mild diarrhea leads to persistent diarrhea, can then develop pseudomembranous colitis, which can cause damage) b. Let's say you're someone who walks around with this bacteria and you're usually fine. You get pneumonia, and you take antibiotics. Now you have unexplained diarrhea. You could have created disruption of good bacteria, bad bacteria (C. difficile) overgrows
Necrotizing Fasciitis a. what is it b. spreading c. treatment d. mechanism
a. severe GAS infection, "Flesh-eating" disease that destroys muscle, fat, and soft skin tissue. b. often spreads very quickly c. IV antibiotics, debridement and possible amputation. d. If bacteria makes its way into a wound, it can spread, rapidly destroying epidermis, dermis, adipose tissue, muscle tissue o At the beginning, there is a lot of pain but you can't see much
Cholera a. V. cholerae is susceptible to ___ b. Cholera toxin c. if untreated: d. treatment
a. stomach acid, so a large infectious dose of 1 to 100 million cells is needed to colonize the intestines b. Once cholera is in GI tract, it's making cholera toxin - acts on epithelial cells on lining - triggers cell to release water - prevents intestines from absorbing water, so it gets sent out of cells. Opposite of wat intestines should be doing - creates watery diarrhea c. fluid loss thickens the blood, leading to shock and coma. d. Antibiotics and oral rehydration therapy (fluid most important)
Detergents a. how do they work b. have ___ zone c. goal:
a. surfactants that cause cytoplasm leakage from microbial membranes b. hydrophobic and hydrophilic c. goal: to break big oily mess into smaller pieces by adding detergent. -hydrophobic part will be attracted to oily molecule/hydrophilic tail will be attracted to water. bridges and makes hell around fat molecule, makes droplets of oil. Once formed, completely surrounded by detergent. The droplets cannot then come together to make big drop of oil, get rid of grime.
Otitis Media a. acute: often results from ___ b. what are the frequent offenders for ear infection? c. describe chronic form d. common in
a. upper respiratory tract infection. b. Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis. c. Long-term infection, inflammation, and damage, often involving persistent biofilm colonization. o Respiratory microbiota can make its way to the ear o S. pneumoniae is part of our natural microbiota o Bacteria could establish biofilm in the ear (difficult to treat) d. young adults/children (Eustachian tube is wide, easier to get infections - harder as you age because Eustachian tube closes more)
Sterilizing Gases a. how do they work b. example c. why are these good/what are they good for?
a. used on heat-sensitive plastics. b. Ethylene oxide is used as the chemical counterpart to heat- and pressure-based autoclaves. c. Controlled, confined environment o Good for liquid that need sterilized but can't stand high temperature - material won't melt with gas o Get into nooks and crannies
Pertussis a. also known as b. highly __ c. caused by d. spread by e. leading cause of ___
a. whooping cough b. dangerous and contagious. c. Bordetella pertussis d. respiratory droplet transmission. e. infant meningitis (vaccine preventable)
Lyme Disease a. is a ___ b. caused by (explain bacterial makeup) c. symptoms (Early) d. symptoms (late) e. treatment
a. zoonosis b. Borrelia burgdorferi is transmitted by the bite of a small tick. - spirochete; specialized structure allows them to be mobile, also has endoflagella running along axis of bacteria c. A bull's-eye rash begins at the site of the tick bite with fever, aches and pains, and flu-like symptoms. e. If untreated it can spread to skin, heart, nervous system, and joints. Late stage develops chronic arthritis and swelling in the joints; cardiac issues, neurological issues f. Treatable by antibiotics in early stages. (doxycycline) - early treatment is essential if any suspicion of tick bite
Gas Gangrene a. treatment b. common in:
a.Treatment is debridement, antibiotics, hyperbaric oxygen therapy, and possible amputation. § Debridement - removal of all dead tissue (if we don't do this, infection will continue to spread and grow) - could result in loss of limbs § Hyperbaric chamber - clostridium is an obligate anaerobe, force increased levels of oxygen deeper into tissues - can help buy time (not favorable for growth) o Death occurs within days if not treated. b. elderly, diabetics
define broad spectrum drugs and examples
affect many taxonomic groups. (more than one group) - Streptomycin, tetracyclines, chloramphenicol o good for mixed infection (multiple species); however, could kill good bacteria
define narrow spectrum drugs
affect only a few pathogens. (will only kill a small variety of bacteria)
what do translation inhibitors do? Only ___ are bactericidal in this group.
affects ability of cell to make proteins aminoglycosides
define microbiostatics
agents that inhibit growth of all microbes
define bacteriostatics
agents that inhibit growth of bacteria
define fungistatics
agents that inhibit growth of fungi
define microbicidals
agents that kill microbes, germicidal
define bactericidals
agents that specifically target and kill bacteria
define fungicidals
agents that specifically target and kill fungi
what antibiotics bind to 30S subunit?
aminoglycosides tetracyclines
beta-lactam antibiotics target ___
bacterial cell wall synthesis
Are cell wall inhibitors bacteriostatic or bactericidal?
bactericidal (destroys entirely, does not just slow growth)
why don't we see cases of malaria in the US?
because we don't have Anopheles mosquitos
which tick is associated with Lyme disease?
black legged deer tick
bacteria: pertussis (whooping cough)
bordetella pertussis
___ is the botulism toxin (one of deadliest known to man)
botox
___ is a life threatening food borne intoxication
botulism
bacteria: diphtheria
corynebacterium diphtheriae
HAP - klebsiella pneumoniae
can cause a primary or secondary pneumonia infection in people with impaired pulmonary function.
HAP -pseudomonas aeruginosa
causes Pseudomonas pneumonia and is seen in immunocompromised patients.
what antibiotics bind to 50S subunit?
chloramphenicol, macrolides, lincosamides
3 types of inflammatory gastroenteritis
cholera, E. coli diarrhea, C. difficile infection (CDI)
bacteria: botulism
clostridium botulinum
bacteria: CD infection (CDI)
clostridium difficile
define waterborne
contamination in water supply
___ is a common but serious complication of gastroenteritis
dehydration
the healthy respiratory tract harbors a ___.
diverse resident microbiome; hundreds of symbiotic microbes inhabit the respiratory tract - spanning across multiple phyla
what tick species is associated with rocky mountain spotted fever?
dog tick
bacterial diseases of the GI tract usually are spread through ___
food and water
define foodborne
food contaminated from the source (manufacturing facility) or person handling food (cross contamination in the kitchen)
which microbes are susceptible to intermediate level disinfectant?
fungi (candida)
bacteria: haemophilus meningitis
haemophilus influenza type B (Hib)
bacteria: peptic ulcer disease
helicobacter pylori
carbapenems use
highly resistant to beta-lactamase enzymes
define cidal
immediately kills
What are the 3 toxin-associated S. aureus contact diseases?
impetigo, scalded skin syndrome, toxic shock syndrome
what leads to antibiotic resistance or superinfection?
improper or excessive use of antibiotics
middle ear infections represent ___
inflammation behind eardrum otitis media is a middle ear infection
pneumonia is ___
inflammation of the lungs
define pharyngitis
inflammation of the pharynx (throat)
define static
inhibits growth of microbes
bacteria: primary/secondary pneumonia
klebsiella pneumonia
bacteria: Legionnaire's Disease
legionella pneumophilia
bacteria: listeriosis
listeria monocytogenes
___ was designed to avoid beta-lactamases
methicillin
why don't we always use UHT?
milk at 140 degrees C would also lose the good stuff - denaturing proteins could make it difficult to digest
define vector-borne disease
mode of transmission is bite from arthropod
bacteria: tuberculosis (TB)
mycobacterium tuberculosis
bacteria: walking pneumonia
mycoplasma pneumoniae
bacteria: meningococcal meningitis
neisseria meningitidis
Describe life cycle of a tick (stages)
o 2 years long, undergo several morphological changes o Egg stage: female releases eggs, hang out in dry places (piles of leaves) § Eggs hatch o First stage: larva - can feed off of small animals (rodents). After blood meal (needed to survive), they change o Second stage: nymph - nymph will look for another blood meal to survive; could happen on larger or smaller animals (including humans), they change o Third stage: adult tick - hang out on deer, male and female ticks will meet and mate, female will drop off onto the ground to release the eggs o Life cycle repeats
purpose of making semisynthetic penicillin (amoxicillin, ampicillin)
o Amoxicillin covers gram-positive and gram-negative (while PCN better for gram-positive) o They can increase number of species susceptible to drug o Attempts to help with antibiotic resistance o Combat resistance by administering two drugs at a time (co-drug) · If you co-administer Clavulanic acid with Amoxicillin, it gives a chance for Amox to work
2 types of semisynthetic penicillins and what they're used for
o Ampicillin and amoxicillin are broader-spectrum drugs. § Can be used to prevent bacterial endocarditis before dental procedures
translation inhibitors and selective toxicity of ribosomes (include why numbers won't add up)
o Both pros and euks have ribosomes, but they are different (we all have ribosomes, but they are compositionally different) § We still have large subunit and small subunit § Numbers deal with how they move in a centrifuge, so they won't just add up
examples of bisphenol
o Chlorhexidine (oral rinse used for dental procedures for prevention of infection, post-surgery), triclosan (popular compound in antibacterial soap) § Soap was doing fine both with and without chemical, didn't need it
how does chlorine control microbial growth?
o Chlorine keeps bacterial populations low in municipal water supplies, pools (disinfect). § Bleach
define invasive gastroenteritis
o Damage to intestinal mucosa, diarrhea, abdominal pain, dysentery with blood and mucus in the feces. § Cause danger to most exterior layers, extend to sub mucosa - some can pass through muscle layer and reach blood stream
tetanus: early and late signs
o Early signs of tetanus: lockjaw (trismus), fixed smile o Arching of the back is later sign - fatal if untreated (permanently contracted diaphragm will not allow breathing - could die of asphyxiation)
If you realize a tick bit you, what should you do?
o Even if you're bit, if you're able to determine how long tick has been on your body, this helps § These ticks need to be feeding on our blood for at least 48 hrs to have enough bacteria transferred from tick to us § How do we know how long? Check engorgement. Is the tick full of blood? Usually they're very small. Ticks can also be sent out for testing.
example of detergents
o Ex. Quaternary ammonium compounds (Quats) react with cell membranes and destroy some bacteria and viruses. § Whenever ammonium is present (low level disinfectant)
how will freezing affect microbial growth
o Freezing foods below 0ºC inhibits metabolism and growth of microbes and can kill certain cells when ice crystals penetrate them. § Many pathogenic bacteria can withstand long periods in freezing temperatures and multiply rapidly when thawed.
define infections
o Infections are illnesses in which live bacterial pathogens are ingested and grow in the body. Pathogen actively growing/dividing in body. Results of that infection are causing signs and symptoms.
Why is Plasmodium falciparum so deadly?
o It's the worst because of the time it takes to go from one cycle to the next o There is no break in peak of signs and symptoms o The others have a little break in signs and symptoms
define MRSA and resistance
o MRSA = Methicillin-resistant Staphylococcus aureus is resistant to semisynthetic penicillins and natural penicillin o Beta-lactam antibiotics will not work with MRSA
Polymyxin B use
o Polymyxin B combined with neomycin and Bacitracin is sold as Neosporin (triple antibiotic ointment) - 3 different classes of antibiotics (polymyxin B kills gram-negative bacteria by attacking their cell membrane)
how to refrigerators affect microbial growth
o Refrigerators reduce food spoilage when kept near 5ºC. § Retards metabolic activity of microbes but does not kill them.
describe mechanism of rheumatic fever
o Rheumatic fever is body's immune response to presence of S. pyogenes - mechanism of immune attack § There is a protein in cardiac tissue that resembles protein produced by S. pyogenes. § Immune system detects bacteria, makes antibodies against pyogenes § They can get confused - mistake protein in heart for bacteria § With rheumatic fever, your own antibodies are attacking your heart - life threatening - mechanism of control: control immune system § Could lead to rheumatic heart disease (heart tissue cannot regenerate itself)
strep throat treatment/complications
o Some patients with strep throat may develop scarlet fever, exhibiting a rash caused by erythrogenic exotoxins. o Rheumatic fever is a serious complication of untreated streptococcal pharyngitis. o Easily treated with antibiotics that are effective against gram-positive bacteria o Do NOT let it run it's course o S. pyogenes is a group A strep, so it should be treated, as some complications can happen if it progresses - could develop scarlet fever (due to production of exotoxin)
Discuss strep throat transmission
o Some people are carriers for S. pyogenes (they have this in their upper respiratory tract, but they have good microbial antagonism, so it doesn't affect them. However, you can pass it to another person, and they can get sick) o Very transmissible
strep throat symptoms
o Starts with sore throat, white plaques on pharynx (often seen), fever -strawberry tongue o Could break out in a rash within days - bacteria are producing and secreting exotoxin - starts to circulate through bloodstream - end up with wide spread body rash
how do sulfa drugs work?
o Sulfa drug can bind to active site in first enzyme of folic acid metabolism o The disruption of folic acid synthesis by competitive inhibition o Folic acid is inhibited in these microbes - folic acid is a building block for nucleotides o If you block this, the bacteria won't have enough nucleic acids to keep going (interpheres with nucleotide production) o Good drug, selectively toxic because our good cells don't have this pathway (we get folic acid from diet), but bacteria do have this pathway o INDIRECTLY block DNA replication
Lyme disease technical name:
o Technical name: erythema migrans (ring starts off compacted, then red ring expands - why it's called migrans)
pertussis basic mechanism
o The disease progresses through three stages as the pertussis exotoxin paralyzes ciliated cells in the respiratory tract (trachea). o Pertussis endotoxin makes its way to ciliated epithelial cells (the ones that push mucus up and out of body) - paralyzes actions of cilia on these cells (cilia can't move) o Any mucus present in trachea becomes trapped - no way to cough out the mucus (you'll cough, but won't get it out)
describe the life cycle of Plasmodium
o The sexual cycle occurs in the definitive host (mosquito). § Host for which that protist is performing sexual phase of life cycle § Must be specific species: Anopheles mosquito o The asexual cycle occurs in the intermediate host (human). § Only asexual reproduction of protist is occurring in our body § These are always the respective hosts o This would be vector transmission · Some parasites need two sets of hosts or more
at what point can a human become affected?
o This bacteria doesn't become transferred to egg (even if mom was positive, eggs will be negative) o Larva will also be negative - if larva bites mouse, this is dangerous. If mouse is carrying bacteria, larva that turn to nymph, nymph will then be positive for bacteria. If you're bit by a nymph, you could get bitten and be exposed to bacteria o If mouse was negative, larva would turn to nymph without the bacteria. If nymph feeds on infected animal, we could have an infected adult tick. You could get infected if bitten by adult tick.
botulism treatment
o Treat using anti-toxin, not antibiotic o Children under 1 to avoid honey -Treated by antitoxins and life-support systems like ventilators
upper vs. lower respiratory tract
o Upper: could include sinuses, nasal cavities, pharynx, trachea o Lower: bronchitis, pneumonia o Upper respiratory defenses limit microbe colonization of the lower respiratory tract o There are many upper respiratory pathogens that can also cause ear pain o Pathogens often use upper respiratory tract to get to the meninges (triple layer that covers brain and spinal cord)
cephalosporins use
o Used in cases of penicillin resistance by the pathogen o Five generations of cephalosporins each with varying degrees of efficacy against Gram-negative and Gram-positive bacteria.
define inflammatory gastroenteritis
o Watery diarrhea, vomiting, fever for 1 to 3 days. § Superficial tissues: epithelial cells, mucus membranes
infant botulism
o accounts for 70% of annual cases ("floppy baby syndrome")
for bacterial ribosomes, antibiotics can:
o act on the small subunit (30S) and those that act on large subunit (50S)
define intoxications
o illnesses in which bacterial toxins are ingested with food and water. Ingested bacterial toxins - different from infection. You ingested toxins made by microorganism.
define fluoroquinolone
o including ciprofloxacin, are used to treat UTIs, STDs, and GI infections
how does iodine control microbial growth?
o used as a disinfectant and an antiseptic on wounds § Ex. Iodophores release iodine over a long period of time. § Many of the iodine compounds are iodophores · Slow release of active iodine element over time
halogens ___ proteins. What are the two main ones?
oxidize chlorine, iodine - high level
which antibacterial agents work to injure the membrane?
polymyxin B
bacteria: pseudomonas pneumonia
pseudomonas aeruginosa
___ prefer colder temperatures and can contaminate foods
psychrophiles
___ will continue to grow because they love the cold
psychrotrophs
define stratum corneum
reason why we have very good protection between epidermis and dermis. Not much can pass through stratum corneum. Thin layer of cells intact and together. Prevents fluid loss and pathogens accessing deeper layers of skin.
toxoplasma is a ___
relatively common blood infection
___ is responsible for 50% of all outbreaks of gastroenteritis
salmonella
bacteria: typhoid fever
salmonella enterica serotype typhi (S. Typhi)
bacteria: salmonellosis
salmonella enterica serotypes
most common foodborne intoxication:
staphylococcal food poisoning, caused by Staphylococcus aureus. o Enterotoxins are often consumed in protein-rich foods (meat, fish, dairy) o The enterotoxin causes gastroenteritis for several hours. o Staph hits the stomach and dies, enterotoxin not affected by acid, goes to intestine (could get this from food being left out too long)
bacteria: folliculitis, boils, carbuncles
staphylococcus aureus
bacteria: impetigo, scalded skin syndrome, TSS
staphylococcus aureus
bacteria: staphylococcal food poisoning
staphylococcus aureus
bacteria: staphylococcal pneumonia
staphylococcus aureus
cold temperatures/freezing are not ___
sterilizing (low temp will inhibit but won't kill)
bacteria: pneumococcal meningitis
streptococcus pneumoniae
Bacteria: Necrotizing fascilitis
streptococcus pyogenes
bacteria: streptococcal pharyngitis (Strep throat)
streptococcus pyogenes
which antibacterial agents work to inhibit DNA precursor synthesis?
sulfonamides
tetanus vs. botulism
tetanus paralysis due to constant contraction of muscle - opposite of botulism · Recall - botulism caused by constant relaxation of muscle § End result for both is paralysis
polypeptide antibiotics affect ___
the cell membrane
the effectiveness of heat for sterilization is a function of ___
time and temperature
bacteria: toxoplasmosis
toxoplasma gondii
what does filtration do?
traps microorganisms
the ___ can be used for early detecting of TB exposure
tuberculin reaction in the Mantoux test
Some protists exist in ___ stages
two different
2 types of irradiation that can be used to control microbial growth
ultraviolet light and ionization radiation
define disinfectants
used on inanimate objects to reduce or eliminate pathogens
bacteria: cholera
vibrio cholerae
mechanism of intoxication
§ Bacteria makes enterotoxin (exotoxin secreted out - entero says target is GI tract) § You eat food with bacteria making enterotoxins like crazy § Bacteria hit stomach and die, enterotoxins are not affected by stomach acid - will persist and make its way through digestive tract § "Poisoned"
HAP - staphylococcus aureus
§ Causes staphylococcal pneumonia. § Insertion of tubing into respiratory tract, staph can hide there
define rice water stools
§ Cholera toxin (exotoxin) causes loss of fluid and electrolytes through diarrhea called rice water stools (you can lose up to 1 L of fluid per hour) - causes dehydration; off white color
the fate of the oocyte has 3 possible fates:
§ Contamination through birds/rodents (toxoplasma forms cysts inside tissues like skeletal muscle) · When cat goes to chew on mouse, gets infected - cycle repeats § Oocytes make their way into livestock like pigs · They might become contaminated · Meat can be consumed by person - could cause infection in humans § Direct contact with Oocysts themselves · No animal intermediates · Ex. Human handles cat litterbox, any type of food/drink contaminated
explain how the GI tract already has innate defense mechanisms already built in
§ Ex. Stomach has acidic pH (if you have a high infectious dose - ingest heavily contaminated water - chance that a small percent of bacteria can make it past stomach and to intestines) § Ex. Process of peristalsis (things moving through intestine - this will also help move invading pathogens through system too)
S. Typhi is transmitted by the five Fs:
§ Flies, Food, Fingers, Feces, Fomites. § Flies landing on feces, then on your food - act as carriers § Fomites: inanimate object (fancy term) - ex. Fork, glass that could be contaminated
Typhoid Mary
§ Home chef from long ago (hundreds of years ago) - put in jail because families she was working for were dying § Turns out she was shedding bacteria into food
Several factors are important in etiological investigations into the cause and origins of an outbreak:
§ Incubation Period § Symptoms § Duration § Demographics
why are carbapenems not a first in line drug?
§ Not given first, try other things first § Be careful in manner in which we prescribe antibiotics § Less resistance to carbapenems in the world than amoxicillin § If it's your first time having strep, try a penicillin first, then work your way up § If we give this out too much, will no longer be effective
obligate anaerobes and hydrogen peroxide
§ Obligate anaerobes lack detoxifying enzymes, can't take care of damaging oxygen free radicals - deadly
paroxysmal stage of whooping cough
§ Patients experience multiple paroxysms of coughs, followed by an inhalation of breath that sounds like a "whoop."
killing a microbe via interfering with metabolic activities
§ Proteins and DNA: · Denaturation of proteins · Disruption of DNA function · (Denature protein - alter 3D shape, limits activity - could affect metabolic activities) - if you crosslink DNA, cell can't replicate or do gene expression
convalescent stage of whooping cough
§ Several weeks of sporadic coughing (Infection clearing, but you're still ill because you've killed your respiratory epithelial cells)
whooping cough vaccine
§ TDaP vaccine contains B. pertussis chemical extracts rather than killed cells. · (a stands for acellular - what today's vaccine) · TDaP given to kids, VTaP given to older people o Being vaccinated against the same thing, dose differs for children, adult version stronger
enveloped vs. non enveloped viruses
· Enveloped viruses have a lipid coat on the outside o These tend to be easier to kill off than the nonenveloped viruses
discuss how the effectiveness of autoclave sterilization is monitored
§ Use indicator to make sure it's working (autoclave tape) § Spore test - take vial that contains bacterial endospores and run autoclave, remove vial and inoculate nutrient rich broth with spores that have been § If there's any bacterial growth in culture broth, you know something went wrong, because endospores should be dead
define moist heat
· (like boiling water) is effective at a lower temperature than dry heat. o It kills microbes by denaturing their proteins. o Boiling water may not kill all spores or inactivate all viruses; unreliable. o Elevating temperatures in some amount of moisture - could be submerged in water or high humidity environment
define toxic shock syndrome (TSS)
· 1980s outbreak with ultra-absorbent tampons; high fever, sunburn-like rash, peeling skin. o Not limited to S. aureus, both staph and strep strains can cause this o TSS toxin circulates through body - you have localized staph infection, but TSS toxin spreads through circulation
describe latent TB
· About 90% of people who carry latent TB will never develop an active infection. o Never develop active disease, infection does not always equate disease o You have latent/dormant TB - you have the bacteria but they're just sitting there quietly o Other 10% could go to primary active TB - about 3 months after exposure - signs and symptoms show up
10% of infections become ___
· Active TB o Body is trying to make tubercles but TB breaks free
define semisynthetic drugs
· Antimicrobials produced by chemically modifying a naturally produced drug. o Base structure of naturally-occurring antibiotic, then modifying in lab.
why is antibiotic resistance a vital concern in the medical community?
· Any bacteria susceptible to the antibiotic should be one that is killed off · In any population, some are biologically different · If some are resistant, take the antibiotic and them kill off · Antibiotic resistant bacteria will bring it back, number will grow - all binary fission occurring for reestablished infection will result in daughter cells that are also resistant · Not antibiotic changing the genetics, it's selecting for what is already there and trying to become the dominant strain. · Resistant cell divides, persister cell (resistant is worse)
incubation period: bacterial GI infections vs. intoxications
· Bacterial GI infections have a longer incubation period than intoxications
describe life cycle of Anopheles mosquito (responsible for signs and symptoms of malaria)
· Begin with bite from female Anopheles mosquito - transfer of specific stage of plasmodium called sporozoites. This is the stage where it is infective to humans. Carried by mosquitos, transferred to us, gets into bloodstream. · Heads toward liver - asexual reproduction occurring to increase numbers · Morphological change into merozoites, which leave liver and attack red blood cells - continue asexual reproduction here · RBCs will burst open, release merozoites - these will then spread to other RBCs and repeat cycle (this is called the intraerythrocyte cycle) · Some merozoites will then change into gametocytes. Sometimes these also burst from RBCs. Some of these are programmed to be male and some are female. · If a mosquito bites a person who is infected by someone with plasmodium, if mosquito drinks blood with at least one male and female gametocyte, sexual reproduction can then occur inside the mosquito's gut · Cycle repeats
TB symptoms
· Blood tinged mucus, unexplained weight loss, night sweats, cough · In the lungs o Bacteria enter lung, body recognizes that they're there o Mounts immune response- immune cells come to lungs, alveolar macrophages engulf bacilli, but are unable to kill bacteria due to cell wall o Forms granulomas in lungs - called tubercles (what we're looking for on an x-ray)
botulism neurotoxin mechanism and source of contamination
· Botulinum toxin is a neurotoxin (target not GI tract, but rather nerves) - still consider foodborne disease - target organ is nervous system · Source of contamination is environmental - botulism spores can be found in ground, shed by animals via feces into soil · Bad idea if you're canning and try to seal something with clostridium botulinum (this bacteria is an anaerobe (low O2 signals spore to germinate and increase numbers) · The neurotoxin inhibits the release of acetylcholine, causing flaccid paralysis and respiratory arrest.
describe the issue with Lyme disease and the bullseye rash
· Bullseye rash is most commonly associated, but not everyone infected gets this rash · Rashes can also appear on parts of body where it's not obvious (i.e. hairline - you may not see bullseye rash if bitten on scalp)
endotoxin vs. exotoxin
· Component of cell wall - released only when cell dies (releases endotoxins) · Exotoxin is different - if a bacteria is producing these, they are synthesized inside cell, not part of structural component o Synthesized and secreted out, cell doesn't need to be dying to produce these o Neurotoxins act on nervous system o Enterotoxins act on GI tract o Typically named after target tissue they affect · Both toxins are bad, but different from each other
botulism symptoms and what it could lead to down the road
· Could lead to respiratory paralysis down the road- acting on muscle's ability to pass synapse - prevents muscle from contracting · Muscles permanently relaxed o Patients can often die because they can't retract diaphragm: called flaccid paralysis
how does one become infected with toxoplasmosis?
· Cyst enters body through various different ways. Excystment happens - active trophozoite is released from cyst. This trophozoite can multiply and, when it's time to exit body, encystment will occur. Trophozoite converts back to cyst stage so it can survive in environment again. Survival mechanism. · Bacteria goes into muscle and lodges there - stays there for life
explain how the digestive system's microbiota is large and diverse
· Differences in anatomy, physiology, and organization along the GI tract generate unique habitats for different species of symbiotic microbes. · Profile of bacteria change from oral cavity to esophagus to intestines/colon (changes as you move down GI tract. Consider oxygenation - large intestine tends to have obligate anaerobes due to the non-oxygen rich environment · Could also have loss of bacterial antagonism (overgrowth of species you don't want - dysbiosis)
gastroenteritis treatment - antibiotics?
· Do we need antibiotics? No. Nothing you can take for this, there's no infection. No antibiotics. Let it run its course.
two different stages of protists
· Exist in the soil in as cysts (similar to endospore of bacteria. Very resistant and dormant stage in life cycle of protist - can survive disinfection, conditions) · Excystment releases trophozoites (active, motile, feeding, dividing stage of some protists)
define acute wounds
· From cuts/bites or from tubes inserted into patients, like catheters or IVs, causing bloodstream infections in hospitalized patients.
gastroenteritis onset
· Gastroenteritis has a fast onset (1-6 hours after eating contaminated food) o As soon as symptoms hit, they're gone in about the same amount of time (24 hours, maybe less)
goal with antimicrobial drugs:
· Goal is to achieve selective toxicity o We want to target unwanted microbe while leaving healthy cells untouched
what happens if your immune status changes in life (TB)?
· If your immune status changes sometime in life, latent TB can be activated (secondary active TB) - ex. Chemo, radiation
define scalded skin syndrome
· In infants and young children; epidermis peels off. o Exfoliative toxins are associated with this - this toxin causes epidermis to peel off
90% of infections become ___
· Latent TB o The tubercle harbors the TB and it stays that way, doesn't affect you · Latent TB is walled off in tubercle - bacteria won't be actively dividing in lungs, but you won't be coughing anything out, so sputum sample should be negative for latent
describe mechanisms of defense of airway epithelium
· Mucociliary clearance traps microbes and particulates larger than 2 µm in a layer of mucus. o Mucus production is protective - microbes could get caught in mucus o Pathogens can be coughed out with mucus o Consider mucociliary elevator: eukaryotic cells are ciliated - movement of cilia in upward moment helps bring up debris /mucus so it can be spat out or swallowed o Certain bacteria interfere with this mechanism · Ciliated epithelial cells move mucus to the pharynx where it is swallowed and sent to the stomach.
describe the mechanism of how cell wall grows and how penicillin works
· Peptidoglycan is present in bacterial cell walls. Will mess with peptidoglycan's ability to make cell wall. o Cell wall can't stretch, gives shape to bacterium - doesn't change o How will it then allow for expansion of volume? Peptidoglycan molecule is made inside cell, inserts itself in the existing cell wall o Inserted between existing peptidoglycan molecules - lengthens layer of these molecules o Beta lactam drugs inhibit ability of bacteria to insert new peptidoglycan molecules into cell wall o Cell keeps getting more volume anyways, but it can't accommodate the volume, so it bursts. o This is how penicillin works o True antibiotic = found in nature = penicillin (made by mold) o Works best against gram-positive bacteria
L. pneumophilia can also cause
· Pontiac fever, an influenza-like infection. o Feel flu-like
problem with TB test and what we do if positive
· Problem with test: it can't differentiate between latent and active TB, it just knows that you came into contact with bacteria at some point · Need follow-up test · Anything positive looking = chest X-ray - this will show anything active · Also use sputum sample - acid-fast stain
problem with TB vaccine
· Problem: there are some countries that vaccinate for TB: BCG vaccine. Skin test/blood test would be positive (bacteria vs. vaccine)
define sanitization
· Reduces pathogen #s to levels considered safe by public health standards o Also disinfection, when we use the word sanitize - we have to disinfect to levels that meet public health codes
define disinfection and how it works
· Reduces the numbers of pathogens or discourages their growth on inanimate objects. o Eventually, microbes will come back (people walk by, chemicals disintegrate) o After a time microbes and potential pathogens will settle and grow on the disinfected object.
how could a skin infection go to bacteremia?
· Skin infections can begin localized, but if bacteria has virulence factors, they could penetrate and go into circulation - could cause bacteremia
describe malaria treatment/prevention
· Still no malaria vaccine · Aminoquinolines: Drugs that accumulate in parasitized red blood cells and interfere with the parasite's ability to break down and digest hemoglobin. o Quinine was the first · There is a lot of resistance to drugs that we use to treat · Since we have a lot of resistance to aminoquinolines, we have artemisinin. These can be taken for prevention, taking before going to area where malaria is prominent.
define primary TB
· The bacilli travel to the alveoli (Primary TB). · In response, macrophages accumulate in the lung, where they engulf but often fail to kill the bacteria. · After a month, the immune response localizes the infection with a multicellular giant mass of cells, including lymphocytes and fibroblasts. o This forms a tubercle that harbors M. tuberculosis.
are polypeptide drugs bacteriostatic or bactericidal?
· These are bactericidal because they lead to cell death (interfering with chemiosmosis/ gradient)
how are polypeptide drugs used? What is the issue with the use?
· These drugs have an unacceptable therapeutic window for internal use so they are generally used topically to treat skin infections. · Problem is that eukaryotes also have a cell membrane- therefore, many are restricted to topical use. If we took these, these drugs would act on our cell membranes too
Mycobacterium mechanism (TB)
· To kill Mycobacterium: use intermediate, high, or chemical sterilant (not low - cell wall too hard for low disinfectant to penetrate) · Has layer of mycolic acid (waxy substance - low disinfectant can't penetrate) · Divides very slowly - due to cell wall - to build layer of mycolic acid is a slow process · Due to slow generation time, someone can be infected by Mycobacterium and not know for up to 3 months · Have to wait period of time if you've encountered TB because may not show up on test
define sterilization
· Treatment of an object to ensure destruction of all living microbes, spores, and viruses. (microbe-free) - spores: fungal or endospores
describe rocky mountain spotted fever treatment
· Treatment: Rickettsias has their own category due to intracellular nature. Changes what antibiotic you'd use. Antibiotic must penetrate cells to get access to bacteria. Tetracyclines work well. Chloramphenicol works but has horrible side effects (aplastic anemia - life threatening).
why is tuberculosis resistant to gram staining?
· Tuberculosis is resistant to gram staining because of different cell wall composition (waxy- contains glycolic acid). Due to this, this is one of the toughest bacteria to eradicate.
discuss thermal death time
· What is the temp that they can't withstand? Thermal death time - if you do not expose microbe long enough, you may reduce numbers but not eradicate.
describe dysbiosis
· When dysbiosis occurs, pathogens can act as opportunists. · Upper respiratory tract filled with many species- prevent pathogens from taking over · Microbiota takes up space so new invader has little room to go - competing for nutrients (number of bacteria decreases when you go lower) · Potential dysbiosis is wherever you have a shift in balance of microbiota
commonalities of protists:
· all nucleated, all single-celled organisms; these organisms must survive by taking advantage of a living host
define gastroenteritis
· an inflammation of the GI tract, usually resulting in vomiting and diarrhea. (also abdominal pain, nausea). Could be caused by infection or intoxication.
co-drugs, such as ___, have been developed to ___. Give example.
· beta-lactamase inhibitors -work synergistically with the penicillin. o Example: Amoxicillin with clavulanic acid (Augmentin)
many penicillin-resistant species produce ___. What do they do?
· beta-lactamases (enzymes that inactivate penicillin) o Beta-lactamases hydrolyze/chew up beta lactam drugs
How do quinolones work?
· block DNA replication in bacteria by inhibiting an enzyme needed for the process. o They work on Gram(+) and Gram(-) bacteria. o DIRECTLY blocks DNA (DNA replication halts - gyrase)
define sulfonamides and what they target
· broad-spectrum drugs and are bacteriostatic. o "Sulfa drugs" target folic acid metabolic reactions. § Preventing nucleic acid synthesis and thus DNA replication. o Target specific metabolic pathway involved in folic acid metabolism
define bisphenol and what they're commonly used for
· combinations of two phenol molecules. (popular derivative) o They are commonly used in disinfection and antisepsis.
TB used to be called:
· consumption because it affects the whole body if untreated
"food poisoning" illnesses can be the result of ___
· enterotoxins: exotoxins that target the intestines.
define microbial antagonism
· healthy respiratory tract Helps prevent infections by outcompeting invading pathogens through the process of microbial antagonism. · Let's say you take an antibiotic to get rid of infection. You could also mess with numbers of good bacteria. Bad bacteria can take advantage of opportunity to overgrow. This would be a dysbiosis (imbalance) o Ex. Bacterial vaginosis, perio
define isoniazid
· interferes with cell wall synthesis only in species of Mycobacterium. o Narrow-spectrum, bactericidal o ONLY mycobacterium - specific to this genera because it interferes with mycolic acid (only found in cell wall of mycobacterium) -block cell wall synthesis
what are polymyxins?
· polypeptides that increase membrane permeability of Gram-negative rods, leading to cell death (Narrow, bactericidal).
how do soaps work?
· remove microbes by emulsifying and solubilizing particles on the skin. (low level)
define dry heat
· requires long periods of exposure to high temperatures. o The heat changes microbial proteins and removes water, slowly burning the microbes.
discuss how ionizing radiation works
· sterilizes materials. o X-rays and gamma rays force electrons out of microbial molecules; this affects cell metabolism and physiology. o Damage is to DNA, x-rays can cause double strand breaks (difficult to repair)
define synthetic drugs
· substance made in the lab to prevent illness or treat disease o Completely lab made, not in nature
define incineration and when it's used
· uses direct flame to kill microbes. (dry heat with direct flame) o In healthcare settings, disposable hospital gowns, dressings, and certain tools can be incinerated. o Decontaminate for disposal (hospital incinerator)
