Flashcards About Micro Final Test

Gram Positive Bacteria, endospore forming, motile rods

• capsule
• exotoxins produce edema&death
• Primary habitat is soil
• zoonotic disease of sheep, cattle, goats
• Portal of Entry determines disease

skin, black eschar - least dangerous

Inhaled into lungs - most lethal

Contaminated meat, can be fatal

• Treated with penicillin, tetracyclin, or ciprofoxacin
• Vaccines
• Live spores and toxoid to protect livestock
• Purified toxoid
• used for high reisk occupations and military personnel
• toxoid - 6 innoculations

• Most serious Streptococcal pathogen
• Gram positive cocci
• facultative anaerobes
• non spore forming, non-motile
• can form capsules and slime layers
• 5-15% carry as normal flora
• Inhabits throat, nasophaynx, occasionally skin
• strict parasite; human only reservoir
• sensitive to drying, heat, and disinfectants
• transmission: contact, droplets, food, formites

• Pharyngitis, tonsillitis, impetigo, strep, scarlet fever
• necrotizing fasciitis (flesh eating disease, when bacteria produces enzymes and toxins that destroy tissue)
• skin infections
• septicemia
• Streptocoocal toxic shock syndrome
• Sequelae

• C-carbohydrates - protect against lysozyme
• fimbrae - adherence
• M-protein - contributes to resistance to phagocytosis
• Capsule - provokes no immune response
• Complement 5a protease - blocks complement and neutrophil response

• Streptolysins - cause cell and tissue injury
• Erythrogenic toxin (pyrogenic) - induces fever and rash
• Superantigens - strong monocyte and lymphocyte stimulants

• Streptokinase - digests fibrin clots
• Hyaluronidase - breaks down connective tissue
• Dnase - hydrolyzes DNA

• Gram positive cocci
• often called pneumococcus
• causes 60-70% of all bacterial pneumonias
• typical pneumonia
• causes 35% of otitis media - inner ear infection
• all pathogenic strains have large capsules
• vaccine for high risk people
• Does not survive long outside its habitat

• Gram positive, irregular shaped Bacilli
• Acid-fast staining
• Strict Aerobes
• possess mycolic acids and a unique type of peptidoglycan
• grow slowly
• 20 hour generation time
• does not produce capsules, flagella, or spores
• produces no exotoxins or enzymes

• complex waxes and cord factor that prevent destruction by lysosomes or macrophages

• inadequate nutrition, debilitation of the immune system, poor access to medical care, lung damage, and genetics
• 1/3rd world population and 15M in US carry it
• Bacillus very resistant to drying and disinfectants
• transmitted by droplets
• worldwide, leading cause of death from a bacterial infectious disease

• Mantoux Test- local intradermal injection of purified protein derivative (PPD)
• look for red wheal to form in 48-72 hours
• in vivo or tuberculin testing
• x-rays
• direct identification of acid-fast bacilli in specimen
• cultural isolation and biochemical testing

• 6-24 months of at least 2 drugs from a list of 11
• vaccine based on attenuated bacilli Calmet-Geurin strain of M.Bovis
• not used in US
• Used in other countries

• only 5-10% of infected people develop clinical disease
• untreated, the disease progresses slowly
• Majority of cases contained in lungs
• clinically divided into:
• Primary
• Secondary (reactivation or reinfection)
• Disseminated (extrapulmonary)

• Infectious dose 10 cells
• Phagocytosed by alveolar macrophages and multiply intracellularly
• after 3-4 weeks, immune system attacks, forming tubercles, granulomas consisting of a central core containing bacilli surrounded by WBCs - tubercle
• if center of tubercle breaks down into caseous lesions, they gradually heal by calcification

• If patient doesnt recover from primary tuberculosis, reactivation of bacilli can occur
• Tubercles expand and drain into the bronchial tubes and UR tract
• Gradually the patient experiences more severe symptoms
• Violent coughing, greenish or bloody sputum, fever, anoerexia, weight loss, fatigue
• untreated, 60% mortality rate

• During secondary illness, bacilli disseminate to regional lymph nodes, kidneys, long bones, gential tract, braing, and meninges
• complications are grave

• Small gram-negative coccobacillus
• capsule, adhesion molecules bind to ciliated respiratory epithelial cells, exotoxins destroy host cells
• causes pertussis, whopping cough- only vaccine preventable disease on the rise in the US

• tiny, gram-negative pleomorphic rods
• fastidious, sensitive to drying, temperature extremes, and disinfectants
• Hib-subunit vaccine available
• sensitive to drying, temp extremes, and disinfectants
• caues acute bacterial meningitis, epiglottitis, otitis media, sinusitis, pneumonia, and bronchitis

• have no cell wall
• highly pleomorphic
• filamentous, moldlike appearance, very small, slow growing
• causes primary atupical, or walking pnuemonia
• becomes a membrane parasite that adheres tightly and fuses with the host cell surface
• fusion makes destruction & removal difficult

1. Streptococcus pyogenes
2. Streptococcus pneumoniae
3. bacillus anthracis
4. Mycobacterium tuberculosis

1. Bordetella pertussis
2. Haemophilus Influenzae
3. Mycoplasma pnuemoniae

• methicillin-resistant Staphyloccus aureus
• carry resistance to many antibiotics
• often treated with Vancomycin as last resort

• occur in people who are or have been in a hospitl or other health care facility within the past year
• typically associated with invasive procedures or devices, such as surgeries, intravenous tubing or artificial joints
• bloodstream infections, surgical-site infections, or pnuemonia

• occur in otherwise healthy people who have not recently been in the hospital (athletes, daycare, military)
• mainly skin infections
• numberof CA-MRSA cases rising

• sinuses have no normal flora
• inflammatory condition of any of the 4 pairs of sinuses
• when sinus openings become lbocked or too much mucus builds, bacteria can grow and form a biofilm
• allergies and cold viruses can cause increased secretions and bacteria may grow

• coarse hairs in nose filter large particles from air
• mucus traps microbes (1-2 quarts)
• cilia moves microbes toward mouth
• lymphoid tissue of tonsils and adenoids
• alveolar macrophages in lungs engulf and destroy microbes
• coughing
• secretory IgA

• Causues over 50% of common cold
• exacerbates asthma
• over 100 types
• incubation of 1-2 days
• grows in temp found in the nose and large airways (33-35 degree C)
• 1 virus = infectious dose
• Bind to cell surface receptor ICAM-1 of the UR tract and dendritic and macrophages cells (attachment to the cells triggers anti-inflammatory response and dampens the immune response
• host inflammatory response causes symptoms and not RV directed cytopathic effects

• RVs disrupt epithelial cell barrier by destroying tight junctions facilitating the transmigration of bacteria
• RVs promote S. Aureus internalization
• RVs stimulate Strep. Pneu. adhesion to tracheal cells
• RVs suppress macrophages and dendritic cells

• Enveloped, crown appearance
• large RNA genome, mutations are common
• causes 10-20% of common colds
• Usually mild human pathogen, but can mutate
• SARS
• MERS
• Common serious vetrinary pathogen
• large animal reservoir

• Severe acute respiratory illness with symptoms of fever, cough, shortness of breath, diarrhea
• SARS mortality 12%
• MERS mortality 43%

• inflammation of lungs - caused by many microbes
• influenza virus
• RSV
• Streptococcus Pneumonia - typical
• Haemophilis infulenza (Hib)
• mycoplasma pneumonia - atypical (walking pnuemonia)

• Enveloped
• 8 RNA segments
• Hemaglutinin and Neuramidndase spikes
• virus attaches and infects cells in trachea - results in localized damagem, NO viremia
• kills 36K Americans/year
• antigenic drift and shift- virus changes&immune system doesn't recognize it
• large waterfowl reservoir

• (H) spike binds to host cells
• Mutations through antigenic drift and shift allow it ot avoid immune response and crossover to new speices

• droplet transmission
• virus attaches to respiratory tract
• attaches to the ciliated comunar epithelial cells lining the sinuses and airways
• replication and inflammation
• localized infection
• no viremia

• Trivalent vaccine each year (3 strains)
• includes 2 A and 1 B strain
• grown in ebryonated chicken eggs, purified H
• takes about 6 mos to produce
• ideal time for vaccination - October through mid-November
• routine annual influenza vaccination recommended for all persons aged 6 mos or older who do no have contraindications

• One of few viruses for which there is treatment available
• 4 anti-influenza drugs
1. amantadine
2. rimantadine
3. relenza spray - blocks neuraminidase
4. tamiflu= capsuel blocks neuraminidase

• most common resp. virus in infants
• infects virtually all by the age of 2 years
• usually causes cold like symptoms
• most common cause of bronchiolitis
• infects UR tract and produces giant multinucleated cells
• epithelia of nose and eye portal of entry- replicates in the nasopharynx
• fever, rhinitis, pharyngitis, otitis, croup
• treatments - Synagis - a monoclonal anitbody that blocks attachement and ribavirin antiviral drug

• Encodes the production of a viral envelope glycoprotein called hemaguttinin, which plays a role in binding to host cell receptors

• Encodes the production of neuramindase, which breaks down the protective mucus in the respiratory tract and plays many roles in viral reproduction

A toxoid; an inactivated toxin (Td or Tdap).  Booser needed every 10 years.

1. Clostridium difficile
2. S. aureus

1. H. pylori
2. Salmonella
3. E.coli

1. norovirus
2. hep a virus
3. hep b virus
4. hep c virus

• gram positive, endospore forming rods
• produces endotoxis A and B
• minor normal resident of intestine
• when antibiotics kill off normal flora, C. diff overgrows
• antibiotic associated coliltis- diarrhea, inflammed color, sloughs off pseudomembrane of fibrin and cells

• saliva
• normal flora of mouth and large intestine (microbial antagonism
• mucous secretions
• IgA
• acidity of stomach
• bile
• rapid movement of material exept through large intestine

• water diarrhea
• fever
• loss of appetite
• nausea
• abdominal pain and tenderness
• 80% healthcare related

• damages cells, triggering inflammation and fluid buildup
• inflamed cells burst and die
• c. diff spores leave colon via diarrhea and await next host
• endospores spread around hospital
• hands must be washed with soap and water; sanitizer does not kill spores
• if possible, stop antibiotics and/or treat with metronidazole or vancomycin

• Gram positive cocci
• Normally inhabits skin and mucous membranes
• withstands high salt
• produces several enzymes
• hemolysins
• leukocidins
• enterotoxins
• exfoliative toxin

• localized to systemic diseases
• abscesses, boils, empetigo, osteomyelitis
• pneumonia, bacetermia, endocarditis, toxic shock syndrome
• food poisoning, intoxication:  enertotoxin requiers 100 degrees C for 30 min to activate
• hands to food ----> temp abuse --> Staph multiplies and releases toxin and 1-6 hours symptoms

Cutaneous lesions and scaled skin syndrome in newborn

infects long bone

• gram negative, comma shaped bacteria
• produces urease, which breaks down urea, producing ammonia that neutralizes stomach acid
• responsible for 90% of peptic ulcers
• dogs and cats carry H. Pylori

• gram negative, facultatively anaerobic rods
• zoonotic- lives in intestinal tract of animals without making them sick
• Most infected with samonella develop diarrhea, fever, abdominal cramps 12-72 hours after infection
• most recover without treatment
• during infection, populations of host bacteria decrease, sugars become abundat, and host inflammation abounts

• gram negative facultative anaerobic rods
• cause 70% travelers diarrhea
• causes 50-80% urinary tract infection
• E.coli is in indicator organism for human fecal contamination

• can cause people to suffer from severe cramps, bloody diarrhea, vomiting, and a low grade fever for 5-7 days
• symptoms show up 3-4 days after ingesting bacteria
• self limited disease in most people
• can be serious and cause hemolytic uremic syndrome, which casues permanent kidney damage and death if left untreated

• presents as acute-onset vomiting, watery non-bloody diarrhea with abdominal cramps, and nausea
• occasionally a low grade fever occurs
• dehydration most common complication
• lasts 24-48 hours
• an infected person can spread the virus for 3 days or more ater diarrhea or vomiting stops
• immunity may be strain specific

• removes and destroys toxins
• stores vitamins, minerals, and sugars
• manufactures proteins involved in clotting, immunity, etc

• inflammation of the liver, producing swelling, tenderness, and sometimes permanent damage
• caused by at least 6 diff viruses:  HAV, HBV, HCV, HDV, HEV, AGV
• non-viral hepatitis may be caused by chemicals, drugs, or alcohol

• fecal-oral transmission
• non-enveloped RNA virus
• classified as an enterovirus
• milder, shorter term disease
• treatment with immune globulin
• vaccine both inactivated and attenuated available
• is not chronic

• transmission through contact with blood, sexual partners, and perinatally
• 7 week incubation period
• can lead to the development of hepatocellular carcinoma
• treatment through interferon and reverse transcriptase inhibitors
• recombinant vaccine produced by yeast available for prevention
• Member of the hepadnavirus, a groupe of enveloped DNA virus
• 50% cases are asymptomatic
• virus cannot be grown in tissue culture
• 10% become chronic carriers

• Transmission is primarily through contact with blood and blood products
• estimated that more than 3 million americans are infected by this RNA virus
• treated through interferon and ribavirin (old) and protease inhibitors (new)
• no vaccine available
• Can be chronic in about 80%
• 1/3 rd of all liver transplants for HCV damaged livers

1. handwashing
2. inactivated&attenuated vaccine available
3. immune globulin

• coagulase enzyme causes blood plasma to clot
• penicillinase enzyme allows s. aureus to grow in the presence of penicillin
• hyalauronidase enzyme promotes invasion of host tissues

1. necrotic tissue causes anaerboic conditions
2. germination of spores
3. production of tetanospasmin toxin
4. excess skeletal muscle contraction
5. respiratory muscles go into spastic, sustained contractions

• gram positive, endospore forming rods
• food poisoning
• found in soil, may contaminate vegetables
• improper canning does not kill spores and can produce botulinum neurotoxin
• neurotoxin blocks release of acetylchole and causes flaccid paralysis (muscles cannot contract).
• die from respiratory or cardiac failure

• Blocks nerve impulses, temporarily paralyzing the muscle that cause wrinkles while giving the skin a smoother appearance.
• relieves migraines, excessive sweating and muscle spasms in the neck and eyes

• Babies don't have well established normal flora
• babies my ingest endospores, which germinate and produce toxin in the body
• c. botulinum does not grow in adult intestines

• Gram positive bacilli, endospore forming rod
• common resident of soild and GI tracts of animals
• causes tetanus or lockjaw, a neuromuscular disease
• endospores usually enter through accidental puncture wounds, burns, umbilical stumps, frostbie, and crushed body parts
• bacteria grows and tetanospasmin - a neurotoxin that causes spastic paralysis

• blocks muscle relaxation
• death occurs from spasms of respiratory muscles
• Vaccine - DPT is a toxoid, inactivated toxin (td or Tdap)
• Vaccine booster needed every 10 years

• gram negative diplococci; meningococcus
• carried in nasopharynx, invades when resistance is lowered; enters bloodstream & meninges
• Symptoms are high fever, chills, lethargy, and a rash
• if meningitis is present, the symptoms will aslo include headache and neck stiffness (which may not be present in infants); seizures may also occur
• in overwhelming meningococcal infections (septicemia), shock, coman, and death can follow within several hours even with appropriate medical treatment
• about 9-12% of persons with meningococcal disease die.  Of those that recover, up to 20% suffer from serious after-effect, such as hearling loss, limb loss, or brain damage

• 5 types:  A, B, C, W135, and Y
• the MCV vaccine contains Neisseria meningitidis serogrop A, C, Y, and W-135 capsular polysaccharide antigens individually conjugated to diptheria toxoid protein
• vaccine does not contain live bacteria
• new vaccine portects against subtype B which casues about 1/3 of all the meningococcus cases in the US

• member of the Herpes virus family, which all cause chronic infections for life & recurrence disease
• 95% US population infected
• causes chickenpox and shingles

• Chickenpox - vesicles virus enters neurons and remains latent
• live chickenpox vaccine

• Shingles with vesicles localized to a dermatone on one side of trunk or face
• live virus shinges vaccine (14X stronger than chickenpox)
• most commonly occurs in people 50 or older or people who are immunosupressed
• shingles vaccine recommended at 60 years

• smallpox is most easily confused with chickenpox
• a single case of smallpox would be considered an act of bioterrorism
• chickenpox lesions at different stages- new lesions appear in crops every few days
• All smallpox lesions should be at the same stage of development
• centrifugal pattern of smallpox lesions

• smallpox was worldwide
• 15M people infected annually
• 2M died with millions more left disfigured and sometimes blind
• 1796-Jenner used cowpox to vaccinate against smallpox
• 1977-last natural cause of smallpox, occurred in Somalia
• 1980-smallpox was declared eradicated

• Largest and most complex virus known
• transmission does not occur until onset of rash, by then most are in bed with high fevers & malaise
• mortality rate 20%-30%

• most easily confused with chickenpox
• all smallpox lesions should be at the same stage of development
• chickenpox lesions at different stages - new lesions appear in crops every few days

• smallpox is stable in aerosol form
• stable on surfaces ~24 hours if not exposed to UV light
• stable on linens, clothes for extended periods
• spreads from person to person by
• aerosol expelled from the respiratory system
• direct contact
• fomites- contaminated clothing
• No known animal or insect reservoir

• Causes Rubeola or red measles
• 8th most frequent death worldwide
• VERY contagious through respiratory aersols
• sore throat, headache, Koplik's spots in mouth then rash, ear infections, pneumonia, ecephalitis, even death
• most serious complication is subacute sclerosing panecephalitis (SSPE) progressive neurological degeneration of the cerebral cortex - 1 in 1M cases
• less than 100 cases/year in US.  Cases have been increasing due to rise of anit-vaxers
• life attenuated measles vaccine, MMR, given 12-15 months

• 1981- CDC first reported new disease.  5 cases of PCP pneumonia in homosexual men
• 1983-Montagnier discovered the cause, a virus, HIV
• 1985- HIV blood test available
• 1996- effective treatment, protease inhibitors and combinations became available

• Sex - anal, vaginal, and oral
• Parenteral - IV drug use, needlesticks, transfusions, transplants
• Perinatal - mother to fetus
• only 25-33% of untreated HIV pass infection to babies
• less than 1% with treatment

• 1.1 M HIV infected people in the US
• 12.5% are unaware of their infection (1 in 8)
• ~50,000 Americans become infected with HIV each year since 1995
• 15,000 Americans die of AIDS each year
• Worldwide, over 33M are infected with HIV
• 30.8 million are adults
• 15.4 million are men
• 15.4 million are women
• 2.5 million are children under 15
• 95% are in developing nations that have 10% of the world's wealth

• semen
• blood
• vaginal secretions
• breast milk

• ssRNA virus, enveloped
• Virion contains 3 enzymes
• reverse transcriptase
• protease
• integrase
• HIV changes rapidly because it lacks correction mechanisms - every time the virus makes a copy there is at least one genetic mistake in the new virus

• 1900s benign simian virus - SIVcpz mutated into HIV1
• stayed in remote Africa until large population settlements established, trade routes, travel and the sexual revolution spread it worldwide

• MUST bind to CD4 and a co-receptor (CCR5 or CXRCR4)
• infects two types of cells
• T4 cells
• Phagocytes - macrophages, and dendritic cells
• infected macrophages travel to brain, lungs, bone marrow
• replicates rapidly and generates lots of mutant strains
• B cells produce antibodies to each new variant

• Binds to CD4 and a co-receptor (CCR5 or CXRCR4) and fuses to host cell surface
• HIV RNA, reverse transciptase, integrase, and other viral proteins enter the host cell
• viral DNA is formed by reverse transcription

• varies substantially among people
• Window period - time before seroconversion (anti-HIV antibodies are not detectable); false neg HIV tests; high viral replication, dangerous time when people might infect others
• usually anti-HIV antibodies are detected between 6 and 18 weeks after exposure to HIV
• Antiretroviral drugs recommended when HIV is diagnosed

• HIV destroys T cells, the body replaces them until body is overwhelmed
• Antiretroviral drugs slow replication
• Without medication, asymptomatic period may last 1-20 years, average is 10 years
• AIDS = less than 200 T4 cells/microliter, presence of HIV, opportunistic infections, and cancers

• blood test for antibodies reactive to HIV
• antibodies are detectable between 6-18 weeks
• window period- people don't produce detectable antibodies for 6 weeks to 1 year after infection.  False negative HIV tests, dangerous time when people may infect others
•  

• does not collect saliva, but a sample called oral mucosal transudate (OMT)
• NOT a saliva test
• OMT contain high levels of IgG antibodies
• tests for antibodies - not virus

• diseases caused by microbes that normally live in or on the body without causing disease in people with normal immune systems
• suppression of the immune system allows the harmless to become harmful
• casued by viruses, bacteria, fungi, and protozoa that are kept in check by an intact immune system
• caused by over 100 microbes
• cam become disseminated (systemic)

• abstinence or fidelity-most effective measure of prevention
• comprehensive sex education
• male circumcision reduces infection by 60%
• tests and get positive people into treatment
• antiviral medication reduces transmission by infected person to unifected person
• PrEP (Pre-Exposure Prophylaxis)-treatment of high risk individuals to prevent infection

• latex - use water based lubricant only
• polyurethane (plastic)- use any lubricant, more expensive, higher frequency of breakage, slippage
• lamb skin- porous, prevent pregnancy, NOT STDS!
• reduces but not eliminate HIV transmission
• Don't use male and female condoms at same time
• 1 in 140 condoms break
• must be used consistently and correctly
• Do not prevent HPV

• gloves
• gowns, masks, and goggles
• careful handling of needles
• disinfection with 1:100 bleach dilution
• preventive treatment after exposure

• valves of bladder prevent backflow of urine to kidneys
• Secretory IgA
• acidity of urine
• urine has lysozyme and lactoferrin
• flushing action of urine
• acidity and normal flora of vagina - microbial antagonism