Microbiology Lecture: Exam Iii

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Chapter 21

1. Chlamydia

2. Rickettsia

Back 1

1. areintracellular (obligate) parasitesGramnegative Bacteria, very small rodsHavea very reduced genomeThreeknown species allare pathogens C.trachomatis causes trachoma (an eye disease)and one of the most common STDs; cannot make ATP

2. SeveralRickettsiaspecies cause human diseases (e.g.Typhus and Rocky Mountain Spotted Fever) need insect vectors

Front 2

1. Chlamydiaand Blindness- Trachoma

2. Rickettsia: Rocky Mt. Spotted Fever & typhus

Back 2

1. Chlamydiainfection - most common cause of preventableblindness in the world.

2. Require living host; Verysmall microbe parasites.Transmittedbloodsucking arthropods such as fleas, lice & ticks. Gram-negative,oval or rod-shaped bacteria;

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1. Rickettsia Epidemic: Typhus

2. Mycoplasma: Pneumonia

Back 3

1. transmitted by lice; 20percent mortality, it kills the victim after about seven days, Can cause gangrene of the tips of the fingersand toes.

2. Smallestorganisms lacking cell walls that can replicate themselvesCause disease in humans, animals, and plants. Can cause (walking) pneumonia

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1. Spirochetes: Treponema – syphilis&Borellia-Lyme Disease

2. Treponema pallidum - Syphilis

Back 4

1. Spirochetesare long and slender bacteriaafraction of a micron in diameter but 5 to 250 microns long. They are tightlycoiled, and so look like miniature springs. Membersof this group are also unusual with axial filaments, which are otherwise similar tobacterial flagella

2. Invade mucosa thru skin breaks; Primarystage: Chancre at site of infectionSecondary:Skin and mucosal rashesLatentperiod: No symptomsTertiary:Gummas on many organsCongenital:Neurological damagePrimaryand secondary stages treated with penicillin

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1. Tuskegee experiment

2. Borellia bergdorferi - Lyme Disease

Back 5

1. AnAmerican Medical MoralFailure

2. Carriedby deer ticks and other ticks; Spread to animals and humans through tick bites. These ticks are about the sizeof a sesame seed. The“bulls eye” rash appears in 75%. Other symptoms of Lyme disease include fever,chills, headaches, stiff neck, fatigue, muscle aches and joint pain; Longterm, arthritis and fatigue

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Treponema pallidum - Syphilis

1. Primary Stage

2. Secondary Stage

3. Latent period

4. Tertiary Stage

5. Congenital

Back 6

1. Chancreat site of infection

2. Skinand mucosal rashes

3. No symtoms

4. Gummas on many organs

5. Neurologicaldamage

*Primaryand secondary stages treated with penicillin

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Non enteric Gram negatives, andunusual bacteria

Back 7

1. Nonenteric pathogens, Yersiniapestis-plague, Pasteurellaanimal Haemophilusmeningitis

2. Spirochetes, Treponema– Syphillis, Borellia- Lyme

3. Curviforms, Helicobacter– Ulcers, Campylobacter– foodpoisoning•Vibriocholera

4. Obligateintracellular parasites, Rickettsia– Typhus,spotted fever -arth.Vector, Chlamydia:STDand Trachoma, blindness

5. Wall-less: Mycoplasma

Front 8

Chapter 22

Fungi as Infectious Agents

1. Molds and yeasts

2. Human mycoses

Back 8

1. Moldsand yeasts are everywhere: in air, dust, fomites, and normal flora, Humans are relatively resistant, Fungi are relatively nonpathogenic 100,000fungal species, 300 have been linked to disease in animals, Fungi:the most common plant pathogens

2. causedby fungal pathogens and opportunistic pathogens

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1. Thermal Dimorphism

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1. When fungal sporesfrom the environment gainentrance to a warm-bloodedanimal, they germinate intoyeasts and remain in thisphase in the host. Yeast cells leaving theanimal host return to theenvironment and revert tothe sporulating hyphal state.These conversions can bedemonstrated on artificialmedia in the laboratory.

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1. Yeasts

2. Dimorphism

Fungal Diseases =Mycoses

3. Systemic mycoses

4. Subcutaneous mycoses

5. Cutaneous mycoses

6. Opportunistic mycoses

Back 10

1. UnicellularfungiBuddingyeasts divide unevenly

2. Pathogenicdimorphic fungi are yeastlike at 37°C and moldlike at 25°C

3. Deep within body

4. Beneath the skin

5. Affect hair, skin, and nails

6. Caused by normal microbiota or environmental fungi; Weakened host

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Fungal Pathogens

1. Opportunist

2. True fungal pathogens

Back 11

1. haslittle or no virulence; host defenses must be impairedVaryfrom superficial -to potentially fatal systemic disease Anemerging medical concern; account for 10% of all nosocomial infections, Gotten in hospital

2. ageographical pattern – climate, soil

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1. Systemic Infections by TruePathogens

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1. Restrictedto endemic regions of the world, Infectionwhen soil w. conidia disturbed, Sporesgerminate in the lungs, Infectioncan become systemic; Causesimmunity

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1. Cutaneousmycoses: Ringworm

2. Preventing Ringworm

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1. Contagious On scalp,body, feet, or nails.Transmission: 1) Skin-to-skincontact with infected person or pet, 2) Indirect contact with object 3) rarely soil. Treatedwith anti fungal

2. Treat People and pets, Avoid contact, Do not share personal items, Clean common-use areas

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1. dermatophytoses

2. Ringworm infection or Tinea

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1. Infections strictly confined toepidermis (skin, hair, nails) ringworm and tinea; 39species in close related genera Trichophyton,Microsporum, Epidermophyton

2. Fungal cause #1 –asexual spores Trichophyton; Warm,moist areas, + minor injuriesSymptoms; Itchy, red, raised, scaly patches -may blister, ooze. Scalp or beard: bald patches. Nails: discolored, thick, crumble. Atone time ringworm was a common disease, Particularly- children of poor; Lack of soap & water. Epidemics

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1. Ringworm of scalp, beard, body

2. Epidermophyton

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1. Tinea capitis, tinea barbae, tina corporis

2. namemeans skinplant, Ringworm, Athlete’sfoot, Jock itch, Nail bed infection; ringworm causes athletes foot.

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1. SubcutaneousInfections: Sporotrichosis (Sporothrix schenckii)

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1. Themostcommon worldwide is sporotrichosis, In gardeners and farmers who come in direct contact withsoil. A chronic infection. 1st: a single pustule at the site ofinvasion. Then lymphatic spread, subcutaneous multiple, painless sores, Canspread to sores in muscles, joints,bones, GI system,etc….

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1. Subcutaneous: Blastomycosis

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1. attacks the weak, soilspores. Affectsthose with compromised immune systems, If spreads, skin or bone lesions: systemicUlcerated; InhaledSymptomsinclude cough and fevercutaneous,bone, and nervous system complications

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1. systemic fungal infections

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1. Infectionsof entirebodyTypicallymoreserious even fatal if immune weakened byAIDS, cancer… Spreadby spores Inhaled or in wound. Somepassed from animals or between humans. Mostboth- yeast & mold

Front 19

1. Coccidioides (valley fever)

2. Histoplasma Infection and Histoplasmosis (Ohio valley fever)

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1. found out west (california), get it from disturbing soil, gives airborne spores, enters through lungs gets into blood stream. Many tissue infections possible from here; true pathogen

2. from pigeon or bat droppings, deep systemic infection can be deadly

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1. Cryptococcus

2. Cryptococcus neoformans

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1. deadly if T cells, Canbe aharmless –lungs or..Meningitis.Dependson the host’s immunity. The most serious: patients with defective T-cell immunity. Such Transplantpatients, steroid patient HIV, Diabetics

2. Cryptococcus neoformanscauses cryptococcosisWidespreadyeast –w. capsuleinhabitssoil around pigeon roosts

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1. Candidaalbicans

2. ^^^ Causes of Candidiasis and due to

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1. Normalflora of oral cavity, genitalia, large intestine or skin of 20% of humansAccountfor 70% of nosocomial fungal infections; Normal flora, painful to eat, Pain, redness Sometimesa white coating or dischargemayhave no apparent cause.

2. Thrush, Vulvovaginal yeast infection, Cutaneous candidiasis inchronically moist areas of skin, Diaperrash and in burn patients; antibiotics because it kills normal flora which is part of immune system, Pregnancy & oral contraceptives, Diabetes, steroids, T cell deficiency. Early AIDS sign Immunosuppresivetherapy.

Front 22

1. OpportunisticFungal Infections: Aspergillosis

2. OpportunisticFungal infection: Pneumocystis

Back 22

1. Acutepulmonary infectionCancause illness 3 ways: Allergic reaction in asthmatics; Scarred lung tissue, Can spread

2. Renamed:Pneumocystis carini, Pneumocystis jiroveci.Aleading causes of illness and death in impaired immune system patients. History:outbreaks in malnourished infants in orphanages in Iran in the 1950s Formscysts in the lungsà

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1. Toxic Fungi Amanita

2. Claviceps purpurea

Back 23

1. deathcap mushroom

2. causesErgotpoisoning, halucinations, circulatory burning: SaintAnthony’s fire, Precursor LSD

Front 24

Chapter 23

Medically Important Protozoans –named by what moves them

1. Flagellates

2. Protozoa

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1. Archaezoa –the ancient ones, Euglena complex cell flagellates, Amebas, Ciliates, Sporozoans /Apicocomplans

2. Eukaryotic,UnicellularHeterotrophs100,000species, 25 are important pathogensVegetativeform-trophozoite.AsexualreproductionAlsoSexual reproduction by conjugation. Someform cysts-survive.

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1. Ancient Flagellates Archaezoa

2. Ancient Flagellate: GIARDIA

Back 25

1. Nomitochondria, Multipleflagella move them, Giardia lamblia & Trichomonas vaginalis

2. Twoforms: Active in gut & Inactive cyst survive for months inenvironment. when eaten Cyst opens in stomach. Watery, smelly diarrhea / soft, greasy stools Abdominalcramps, bloating NauseaFatigueWeightloss –10 to 15 pounds in adults Orno symptoms, but transmit.

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1. Giardia lamblia andGiardiasis

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1. PathogenicflagellateUniquesymmetrical heart shape with a suction cupCystsare small, compact, and multinucleateReservoirsinclude beavers, cattle, coyotes, cats, and humansCystscan survive for 2 months in environment

Front 27

1. Trichomonas vaginalis: Common protozoan STD

2. HemoFlagellates

3. Trypanosoma

4. Leishmania

Back 27

1. Trichomonas vaginalis is a sexually transmitteddisease (STD. Most people infected no symptomsIfSymptoms: White discharge &itching. Protozoans in secretions, Metronidazole

2. blood borne: Important ones Trypanosoma & Leishmania

3. Undulating membrane= flagella, transmitted by vectors.

4. Flagella form in sand fly vector

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1. Trypanosoma

Back 28

1. Sleeping Sickness & Chagas’disease, AfricanSleepingsickness is Spread by tsetse fly Sleepingsickness signs: high fever, weakness, headache, joint pains. As resistance weakens anemia, cardiovascular, kidney disease, abortion. Finally parasite invades the brain & behaviorchanges-lethargy. Coma & death follow.

Front 29

1. Trypanosoma cruzi – Chaga’sdisease

2. Leshmania

Back 29

1. Heartmuscle and large intestine harbor masses of amastigotes, Chronicinflammation occurs in the organs (especially heart and brain)Chaga’s disease in tropical Americas spread by “kissing bug “ Eye swells at bite wound or if fly feces were rubbed eye. Severe in 1% only

2. Flagellate infection, First:skin reactions – a large soreVisceral: fever, weight loss,swelling of liver & spleen; anemia

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1. Amoebas

2. AmebasEntamebahistolytica

Back 30

1. Moveby pseudopodsEntameba–medically important

2. Amebicdysentery Transmittedby fecal contamination in water and food, also direct contact: dirty hands or sex, or objects.Infectionmay be long term, GI distress or blockage cause rare fatalities.Cystsshed in feces, Asymptomaticin 90% of patientsAmebamay secrete enzymes that dissolve tissues and penetrate deeper layers of themucosaCausingdysentery, abdominal pain, fever, diarrhea, and weight lossCarriedby 10% of world population

Front 31

1. Naegleria fowleriand Acanthamoeba

2. Ciliophora (Ciliates)

Back 31

1. Amebic Infections of the Brain, Ordinarilyinhabit standing waterPrimaryacute meningoencephalitis is acquired through nasalcontact with water or traumatic eye damageInfiltrationof brain is usually fatal

2. Moveby ciliaComplexcellsBalantidiumcoli is the only human parasite. ex paramecium

Front 32

1. Balantidium coli

2. Sporozoansor Apicocomplans and types

Back 32

1. not free living, causes GI distress, Thisparasitic species infects the large intestineItcan invade the mucosa causing: Severecolitis with ulcerations like amoebic dysentery

2. All are parasites. Allare non movingHave"apical complex" (microtubules) at tip. Apical complex bores into host! Allhave complex life cycles. Plasmodium: malaria, Toxoplasma gondii - toxoplasmosis, Cryptosporidium & cyclospora – GI distress – emerging and in HIVpatients Babesia – a new tick born disease

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1. Plasmodium

Back 33

1. causes malaria, Spreadby the female Anopheles mosquito with parasites in itssalivaSerious and sometimes fatal. TheWorld Health Organizationestimates each year 300 million cases of malaria; Close to one millionpeople die of malaria. Symptoms: fever, headache, aches, tiredness, nausea, vomiting, and diarrhea. Anemia due to blood loss.Symptomsrecur in crisis periods

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1. Life stages Plasmodiuminfection (5 stages)

Back 34

1.Parasites enter host's blood when bittenby infected mosquito

2. Migrate to liver& multiply

3.Return to bloodstream to invade red blood cells...

4.Parasites multiply in red cells until they burst releasing many parasites into the blood

5.Crisis and fever Occursin cycles of 48 hours.

Front 35

Plasmodium life cycle terms

1. Sporozoites

2. Gametocytes

3. Trophozoites

4. Zygote

Back 35

1. infectivecells

2. sexcells of parasite

3. feeding forms

4. fertilizedegg

Front 36

1. Toxoplasma gondii and Toxoplasmosis

2. Cyclospora

Back 36

1. Intracellularapicomplexan parasite with extensivedistribution, Livesnaturally in cats that harbor oocysts in the GI tract, Acquiredby ingesting raw meats or substances contaminated by cat fecesFetus& HIV patients

2. Anemerging protozoan disease: flu like + watery diarrhea.Fecaloral, contaminated veggies

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1. Cryptosporidium

2. Babesia

Back 37

1. watery diarrheaDeadly in HIV patients; newly recognized intestinal pathogen, Noeffective drugs

2. newly recognized tick borne illness, Tick-transmitted, CausesMALARIA-LIKE symptoms and HEMOLYTIC anemia. Rare(200 cases) but can be serious. Emerging-public health significance in the U.S. increased reports of clinical, even fatal, cases

Front 38

1. Helminths (Parasitic Worms)

2. Phylum: Platyhelminthes

3. Phylum: Nematodes

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1. Eukaryotic,Multicellular animals, with organsHeterotrophicKingdom:Animalia

2. Flatworms- Class:Trematodes-Flukes- Class:Cestodes-Tapeworms

3. Roundworms

Front 39

1. Reproduction: Helminth Parasites

Back 39

1. Adultworms mate and produce fertilized eggs that hatch; larvae then mature in stages to adults, Thesexes may separate or hermaphroditicAdulthoodand mating occur in the definitive,primary hostLarvaldevelop occurs in the intermediatehostA transporthost experiences no parasiticdevelopment§Fourbasic patterns of life and transmission

Front 40

A. Nematodes/Roundworms

Types of roundworms

1. Pinworm

2. Ascaris

- Hookworm

3. Whipworm

4. Onchocerca

5. Trichinella

6. filarial

Back 40

A. Eggs can be Infective to Intestine

1. Enterobius

2. largeintestinal roundworm ->

3. Trichuris

4. Theriver Blindness parasite

5. causestrichinosis

6. TheElephantiasis parasites

Front 41

1. Ascaris

Back 41

1. Intestinal Roundworms, grows6 to 16 inches, & may grow as thick as a pencil. Commonworld wide. In areas of poor sanitation, everyone may have the worm. Amazingly,up to a hundred worms can infect one person. Carelessnesscauses ascaris. Human feces in streets, fields, and yards. Dogsand cats may pass a different species of ascaris, Rarelyfatal if brain infected or intestine blocked

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1. Ascaris lumbricoides

2. Whipworms

Back 42

1. Severeinflammatory reactions mark the migratory route; Allergicreactions can occur, Heavyworm loads can retard physical and mental development

2. a mild intestinal parasite Trichuris, Wormhas long, very thin, whiplike shape, Eggs develop outside body, warm, moist, shaded soil. Oftenno symptomsDiagnoseit by examining stool and finding eggs.Heavy infections: intermittent stomach pain, bloody stools, diarrhea-worms pierce intestine, weight loss.Incidenceof whipworm infection is high but symptom intensity is usually light. BUT can be fatal inchildren

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Concept check:

Hemoflagellates are transmitted by

Back 43

Insect Vectors

Front 44

1. Pinworms Enterobius

Back 44

1. Mostcommon roundworm parasite in US temperate areas even with good sanitation.InUS affects up to one-third of children some areas. Commonin day-care centers, schools, and camps.Pinwormsare small, threadlike roundworms found primarily in the colon and rectum

Front 45

1. Hookworms

Back 45

1. Characteristic curved ends and hooked mouths; Necator; Humans shed eggs in feces, which hatch into filariform larvae and burrow into the skin of bare feet;

Oneof the most common roundworm infections. Transmission:unsanitary conditions. Eggs are passed in feces onto the ground develop into infective larvae. Mostlytropical.

Larvalworms crawl to soil and extend their bodies into the air. They wave about until they come into contactwith skin of barefoot. Theybore in & go by blood -lungs, climb, then swallowed to gut.

Front 46

1. Trichinella spiralis and Trichinellosis

Back 46

A. Lifecycle entirely within mammalian host (pig)

1. Larvae encysted inanimal muscle are theinfectivestage

2. When ingested, cystshatch and mature in theintestinal lining.

3. Adults reproduceand form new larvae.These burrowthrough the intestineand enter thecirculation.

4. Larvae eventually formcysts in skeletal musclethat can remain for years.Circle shows a biopsy ofhuman skeletal muscleinfected with the coiledlarvaeof Trichinella spiralis

Front 47

1. Onchocerciasis

2. filarial roundworms

Back 47

1. river blindness, Transmittedby the bite ofsmall black fliesthat breed in streams and rivers ;major cause of preventable blindness.

2. Elephantiasis thickening of the skin andtissues, legs and genitals. obstructionsof the lymphaticvessels. Nematodescause lymphatic filariasis transmittedby mosquitoes.Theparasite occupieslymph vessels that drainthe lower extremities

Front 48

1. FLATWORMS

Back 48

1. TheBlood Fluke Schistosoma; ContractedSwimming, fishing Schistosomiasis: second most importantinfection hundreds of millions. Oraland ventral suckers. Blind-ending digestive system – no anus; All flatworms have this digestion. Many flukes are hermaphrodites

Front 49

1. Blood Fluke life cycle

Back 49

1. Adultworms enter blood vessels. Eggspassed through urine or feces to fresh waterSnailas intermediate host to mature; Clogged waterways hurtLarvainfects- penetrates skin. Separate sexes-female attached to smaller male

Front 50

1. Liver fluke disease

2. Chinese Liver Fluke

Back 50

1. Causedby sheep liver fluke Caninfect humans accidentally. Inagriculture, billions of dollars oflosses meat, milkFlukein liver, acute: Abdominal pain, enlarged liver, Fever, vomiting, diarrhea. Can last for months.Chronic-adultfluke in bile ducts

2. Raw fish

Front 51

1. Cestode (Tapeworm) Infestations

Back 51

1. Flatworms: Long,very thin, ribbonlike bodies composed of sacs (proglottids) and a scolex that grips the intestine. Eachproglottid is an independent unit adaptedto absorbing food and making and releasing eggs. Taenia saginataTaenia solium

Front 52

1. Tapeworm life cycle

2. Human primary host - intestinal symptoms

Back 52

1. Eggspass out in feces

2. Intermediate host -cyst forms, serious symptoms possible:: As humans: larvae encyst in our organs.

3. Cyst may be passed if predator eats rawmeat of intermediate

4. Definitive Host -intestinal symptoms

* Humans can be primary or intermediate host --------------------------------------------------------------

2. WeightlossVitamindeficiencyRarely,intestinal blockage

Front 53

1. More on Tapeworms

Back 53

1. Adulthas: Head or scolex, where worms attach to gut;plus, Neck, Segmented body contains male and female gonads. Rows of teeth to grab on with; Absorbsnutrients through skin as the host’s food passes by. Oldersegments pushed to tail, full of eggs. Eggsegments drop off to spread. Can be up to 30 feet.

Front 54

Different types of Tapeworms

A. The fish tapeworm

B. Beef tapeworm

C. Pork tapeworm

D. Rodent tapeworm

E. Dog tapeworm

Back 54

A. 30 feet Longest tapeworm to 4,000 segments

B. eating undercooked beef with worm cysts, 25 feet long.

C. up to 21 feet

D. intermediate carrier, such as fleas, beetles, and cockroach up to 20 inch long in the intestine.

E. usually children accidentally eat infected flea or louse to 24 inches.

Front 55

Chapter 24

1. Fusion

2. Releaseof an Enveloped Virus by

3. All DNA viruses are:

4. All RNA viruses are:

Back 55

1. Attachment,Penetration, and Uncoating

2. Budding

3. are double-stranded except for parvoviruses, which have ssDNA

4. aresingle-stranded except for dsRNA reoviruses

Front 56

1. EnvelopedDNA Viruses

2. Smallpox

Back 56

1. Poxviruses, Herpesviruses, & Hepadnaviruses

2. Eradicationand Bioterror, Smallpoxravaged Europe, then introduced to the Americas devastated the nativepopulation. It has shaped history. Vaccine available.

Front 57

1. Latentinfection in animal viruses: Herpes, HIV,Hep…

2. TheDNA Viruses: Herpes

3. TheStructure of Herpesviruses

Back 57

1. DNAviruses or retroviruses caninsert into host DNA, poppingback to the lytic active infection during stress or immune suppression. Herpes inserts into nerve cell roots, and shingles occurs along the nerve.

2. Herpesvirus, HSVsimplex 1, 2 Varicellazoster, EpsteinBarr, CMV-cytomegalovirus, Roseola, HumanHerpesvirus-8

3. Largeenveloped icosahedral dsDNA, Replicateswithin nucleus

Front 58

1. Herpessimplex 1&2

Back 58

1. Herpessimplex 1 causes cold sores, Fluidfilled blisters hurt, Herpessimplex 2 is genital herpes, an STD, Herpescan infect a newborn causing death orbrain damage, Bothtypes of the virus can be transmitted through direct contact.There'sno cure for herpes. Onceinfected it's in the body forever. Acyclovirhelps

Front 59

1. Herpeslabialis (type 1)

2. Genitalherpes – herpes genitalia (type 2)

Back 59

1. fever blisters, cold sores; most common, Vesicles, lesioncrusts over 2-3 days, heals inyoung children; fever, sore throat, swollen lymph nodes

2. startswith malaise, anorexia, fever, swelling and tenderness in the groin; clustersof sensitive vesicles; vesicles ulcerate, Recurrentbouts less severe, triggered by menstruation, stress, and concurrent bacterialinfection

Front 60

1. Herpesof the Newborn

Back 60

1. HSV-1and HSV-2§Potentiallyfatal in the neonate and fetus; Infantcontaminated by mother before or during birth; hand transmission by mother toinfant§Infectionof mouth, skin, eyes, CNS, Preventativescreening of pregnant women; delivery by C-section if outbreak at the time ofbirth

Front 61

1. Herpesviruses

2. Shingles

Back 61

1. Varicella-zostervirus (human herpes virus 3) Transmittedby the respiratory route, Causespus-filled vesicles; Virusmay remain latent in dorsal root ganglia

2. Reactivationof latent HHV-3 releases viruses that move along peripheral nerves to skin.

Front 62

1. EpsteinBarr

2. CMV = Cytomegalovirus.

3. Infectiousmononucleosis

Back 62

1. extremelycommon in US. Infectionin adolescence or young adulthood causes infectious mononucleosis 40% of thetime. Enlarged liver or spleen, fever& fatigue.

2. Newborns’, Transplant patients, HIV patients

3. sorethroat, high fever, cervical lymphadenopathy; develop after 30-50 dayincubation; Dormancyin B cells; reactivated; may be asymptomatic

Front 63

Chapter 13

A. Normal Microbiota

Flora of the Human Skin Two types:

1. Transients

2. Residents

Back 63

A. compete for you!, Microbialantagonism is a competitionbetween microbes. Normalmicrobiotaprotect the host by: Occupying places that pathogensmight occupy–Producing acids and bacteriocidins!

1. influenced by hygiene

2. stable, predictable,

Front 64

1. Flora of the Gastrointestinal Tract

2. Truepathogens

3. Opportunisticpathogens

4. virulencefactor

Back 64

1. GI tract: exposed to environment, Mucous membrane barrier Oral cavity, colon, rectum: most flora–Saliva: 5 x 109 cells/mL!

2. capable of causing disease in healthypersons with normal immune defenses–Influenza virus, plague bacillus,malarial protozoan

3. cause disease only–host’s defenses are compromised or –when they grow in part of the body thatis not natural to them, Severity determined by: virulence of pathogen

4. factors of microbe to cause disease

Front 65

1. Typical pathogen entry routes

2. Portals of Entry: Skin, GI, Respiratory, Urogenital, Transplacental

Back 65

1. mucous membranes, skin, Open wound, Parenteral; Without preferred entry, pathogen may beharmless

2. Skin: nicks, abrasions, punctures, incisions–

Gastrointestinal tract:food, drink, other ingested materials

Respiratory tract: oral and nasal cavities

Urogenital tract: sexual, displaced organisms

Front 66

1. Requirement for an Infectious Dose (ID)

2. Adhesion

3. Surviving Host Defenses: Antiphagocytic factors

4. Entering Host Tissues

Back 66

1. Minimum number of microbes required forinfection to proceed, Microbes with small IDs have greatervirulence , Lack of ID will not result in infection

2. binding between specific molecules onhost and pathogen: Fimbrae, Flagella, Glycocalyx, Cilia, Suckers, Hooks, Barbs

3. leukocidins, toxic to white blood cells, Slimelayer orcapsule, Ability to survive intracellularphagocytosis

4. Salmonella secrete virulence proteinsdirectly into the host cells

Front 67

Causing Disease

1. Virulence factors

2. Exoenzymes

3. Toxigenicity

Back 67

1. to invade and colonize host, May cause tissue damage– severity ofdisease

2. dissolve barriers, penetrate cells

3. produce toxins at the site ofmultiplication

Front 68

Bacterial Toxins: A Potent Source of Cellular Damage 2 Types:

1. Endotoxin

2. Exotoxin

Back 68

1.released after the cell is damaged; Composed of lipopolysaccharide (LPS), From outer membrane of gram-negative cellwalls, causes fever, not neutralized by antitoxin

2. toxin secreted by living bacterial cellinto tissue; Strong specificity for a target cell; are proteinssquirted outof the pathogen, Amongthe most potent toxins known: Botulism and tetanus toxin for ex. Heat labile,– because they are proteins, Anti-toxin can be made; Created mainly by Gram positives,Staphylococcus–Clostridium; a few Gram negatives–Cholera toxin

Front 69

The Process of Infection and Disease, 4 distinct stages of clinical infections:

1. Incubation period

2. Prodromal stage

3. Period of invasion

4. Convalescentperiod

STOPPED AT SLIDE 46

Back 69

1. initial contact to first symptoms, agent is multiplying but little damage, no symptoms; several hours to severalyears

2. vague feelings of discomfort;

3. multiplies at high levels; more specificsigns and symptoms

4. responding to the infection, symptomsdecline

Front 70

1. Local infection

2. Focal infection

3. Systemic infection

4. Septicemia, bacteremia

5. Primary vs Secondary

Back 70

1. ex. boils, in one area

2. ex. sinus infection, tooth abcess

3. ex. typhus

4. Bacteria growing in blood

5. Primary-Example: flu. - The patient is weakened & anotherinfection may take hold, such as pneumonia – the secondaryinfection

Front 71

1. Acute infection

2. Chronic infection

3. Signs of Infection in the Blood

4. Septicemia

5. Bacteremia

6. Viremia

Back 71

1. comes on rapidly, with severe butshort-lived effects, ex. flu

2. progress and persist over a long periodof time, ex. Hansen's disease

3. Changes in white blood cells–increase –decrease

4. microbes multiplying in blood –present in large numbers

5. small numbers of bacteria present inblood not necessarily multiplying

6. small number of viruses present notnecessarily multiplying

Front 72

1. Asymptomatic

2. Portals of Exit

Back 72

1. (subclinical) infections –infected, buthost shows few signs of disease–“walking” pneumonia, person doesn’tseek medical attention–Can spread the infection!

2. Pathogens depart by a specific avenue; greatly influences spread of infection: Respiratory– mucus, sputum, nasal drainage, saliva, Skin dandruff, Fecal, Urogenital, Removal of blood

Front 73

1. Latency

2. Chronic carrier

3. Reservoir

4. Source

Back 73

1. the microbe hides! Can become active and produce a recurringdisease;

2. person with a latent infection who shedsmicrobes

3. primary habitat of pathogen in thenatural world: Human or animal carrier, soil, water,plants; ex. AIDS, gonorrhea, animals

4. individual or object from which aninfection is actually acquired

Front 74

1. Typhoid Fever: Carrier infection

Back 74

1. Mary Mallon, an Irish immigrant near 1900worked as a cook. She had a subclinical case of TyphoidFever – never even knew it. She remained infective all her life, transmitted to 47 people, 3 died. Salmonella typhiremains on the hands from feces – evenafter washing

Front 75

1. zoonosis

Back 75

1. An infection indigenous to animals & Naturally transmissible to humans. Humans don’t transmit the disease to others . At least 150 zoonosesexist worldwide; make up 70% of all new emerging diseases, Impossible to eradicate the diseasewithout eradicating the animal reservoir

Front 76

2 kinds of Zoonosis

1. Direct transmission

2. Vector transmission

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3. Vector

Back 76

1. through the bite, saliva, scratch, etc ofthe infected animal.

2. Ex: Lyme, malaria, sleeping sickness

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3. A live animal that transmits from onehost to another( Most are arthropods – fleas, mosquitoes,flies, and ticks/Some larger animals can also spreadinfection – mammals, birds, reptiles)

Front 77

1. Biological vectors

2. Mechanical vector

3. Transmission- Vehicle

Back 77

1. actively participate in a pathogen’slife cycle

2. transports microbe without being infected; They walk on the food rather than bitingyou & carry their body the infectingmicrobe gotten from another source

3. by an inanimate shared reservoir-food, water, air, fomites, biological products

Front 78

1. Communicabledisease

2. contagious

3. Directcontact

4. Indirect contact

5. Airborne

Back 78

1. infected host can transmit to anotherhost

2. Highly communicable disease

3. physical contact or fine aerosol droplets

4. passes from infected host to intermediate conveyor and then to anotherhost

5. droplet nuclei, aerosols

Front 79

1. Nosocomial Infections

2. Universal Blood and Body FluidPrecautions

Back 79

1. Diseases that are acquired or developedduring a hospital stay from surgical procedures, equipment,personnel, and exposure to drug-resistant microorganisms, most common + cocci

2. Stringent measures to prevent the spreadof nosocomial infections, assume all pt have infect.

Front 80

1. Epidemiology

2. Prevalence

Back 80

1. The study of the frequency anddistribution of disease; Reportable, notifiablediseases must be reported to authorities: Centers for Disease Control andPrevention (CDC) keep track of infectious diseases nationwide

2. total number of existing cases withrespect to the entire population -a percentage of population

Front 81

1. Incidence

2. Mortality rate

3. Morbidity rate

Back 81

1. measures the number of new cases over acertain time period, as compared with the general healthy population

2. the total number of deaths in apopulation due to a certain disease

3. number of people afflicted with a certaindisease

Front 82

1. Endemic

2. Sporadic

3. Epidemic

4. Pandemic

Back 82

1. steady frequency over a long period oftime in a particular geographic area

2. occasional cases at irregular intervals

3. when prevalence of a disease isincreasing beyond what is expected

4. epidemic across continents

Front 83

1. Koch’s Postulates:

Back 83

Determining the causative agent of adisease:

1.Find evidence of a particular microbe inevery case of a disease

2.Isolate that microbe from an infectedsubject and cultivate it artificially in the laboratory

3.Inoculate a susceptible healthy animalwith isolated microbe and get the same disease

4.Reisolatethe agent from this subject

Front 84

Chapter 6

1. The Position of Viruses in the BiologicalSpectrum

2. Virionsize

Back 84

1. Discoveredvia Electron microscope, Perhapsmost abundant microbes on earth, Importantin evolution &ecology, obligateintracellular parasites - Layeredstructure

2. Sizerange – most <0.2 μm;requires electron microscope, can be crystallized

Front 85

General Structure of Virus

1. Capsids

2. envelope/naked

3. Capsidtype #1: Helical

4. Capsidtype #2: Icosahedral

Back 85

1. Proteincoat madeof identical protein subunits called capsomers

2. Someviruses have an external covering called an envelope;those lacking an envelope are naked (typical DNA virus)

3. formsa cylinder

4. 20-sidedwith 12 corners

Front 86

1. Viral envelope

2. spikes

3. Functions of Capsid/Envelope

Back 86

1. Mostlyanimal viruses–Stolenwhen the virus leaves the host cell!

2. forattachment of the virus to the host cell glycoprotein

3. Protectsthe nucleic acid when the virus is outside of the host cell, helpsthe virus bind to a cell surface and assists the penetration of the viral DNAor RNA into a suitable host cell

Front 87

Complex Viruses: Pox and phage

1. Complex

-bacteriophages

Viruses types: DNA or RNA

2. Double-strandedDNA

3. Single-strandedRNA (2 types)

Back 87

1. viruses:atypical viruses, Poxviruseslack a typical capsid, coveredby a dense layer of lipoproteins

–polyhedralnucleocapsid - Plushelical tail, pins and attachment fibers (they infect bacteria)

2. Ex.herpes &pox-bacteriophages

3. Mostare plus stranded(sense)actsasmessengerRNA, Someare minusRNA: an enzyme makes a new RNAstrandto be a messenger, Oneis double stranded RNA!(rotavirus)

Front 88

1. Viral Reproduction: Five Steps

2. Damage to Host Cell

3. Lysogeny

Back 88

1. ADSORPTION-–sticking

2. PENETRATION–And uncoating

3. SYNTHESIS–Ofnucleic acid & protein

4. MATURATION–assembly

5. RELEASE–Andrecoating

2. Cell lysis, Lyticcycle, Alter DNA, Transform cells into cancerouscells

3. When viruses Hide in host DNA: howsneaky!; virus is Temperate,no spreading or bursting, may be dormant

Front 89

1. The lytic cycle

2. Provirus

Back 89

1. conversion happens, Active & spreading infection

2. Viruslies dormantin infected cell, theirDNA within host cell, ViralDNA replicateswith host DNA. Thevirus is now called a PROVIRUS. Itexpressessome genes in host: Makehost immune tonew viral infection–Maymake atoxin:ex. diptheria –Somepromote CANCER Ex.HPV Calledoncovirus

Front 90

1. Growing Viruses

2. Prions

Back 90

1. Animalviruses may be grown in living animals or in embryonatedeggs. Animaland plants viruses may be grown in cell culture.

2. misfoldedproteins, no nucleic acid, Extremelyresistant to usual sterilization techniques, Causespongiform encephalopathies: fatal neurological diseases

Front 91

Prion disease

1. Scrapie

2. Bovinespongiform encephalopathies

3. Wasting diease

4. Creutzfeldt-Jakob Syndrome(CJS)

Back 91

1. insheep and goats

2. (BSE),a.k.a. mad cow disease

3. inelk

4. in humans

Front 92

Chapter 24 continued at slide 28

1. Cytomegaloviruses

2. Roseola- Herpesvirus 6

Back 92

1. CMV Producegiant cells with inclusions Transmittedin fluid secretions §latentin various tissues

2. Roseola is acommon disease of babies or young children, in which several days of very high fever arefollowed by a characteristic rash. Very common.

Front 93

1. Other Herpesvirusesand the Cancer Connection

Back 93

1. HHV-7is closely related to HHV-6 and causes similar diseases, Cancer link HHV-6 and Hodgkin’slymphoma, oral carcinoma, T-cell cancers, Epstein Barr: a type of lymphoma, nasopharynx cancer

Front 94

1. Human Herpes virus 8 – Kaposis sarcoma virus

Back 94

1. Human herpes virus 8: (HHV-8) is thought to cause Kaposi's sarcoma, a type of cancer prevalent among those with HIV. Symptoms? §In most infected people, HHV-8 lies latent. §in people with a weak immune system - particularly those with advanced HIV, HHV-8 can lead to Kaposi's sarcoma, resulting in purple lesions on the skin or inside the mouth, which become large, raised and painful.

Front 95

1. Varicella and zoster are caused by

2. Hepatitis

Back 95

1. the same virus

2. aninflammatory disease of liver cells that may result from several viruses, Interfereswith liver’sexcretion of bile pigments, §bilirubinaccumulates causing jaundice, a yellow tinge in skin and eyes, 3principal viruses involved in hepatitis: Hepatitis B, hepatitis A (RNAvirus), hepatitis C (RNA virus)

Front 96

1. Hepatitis B – DNA virus Risk liver cancer, fluids transmit

Back 96

1. Hep B is double stranded DNA virus, Hepatitis B is a contagious liver infection caused by the virus. 5,000deaths each year in the United States from chronic liver disease or livercancer. Jaundice,fatigue, muscle pain, GI discomfort HepatitisB vaccine available, Canbe transmitted by body fluids from an infected mother to her baby at birth, through unprotected sex, by sharing equipment for injecting street drugs occupationalcontact - healthcare

Front 97

1. Hepadnaviruses

2. Hepatitis B DNA Virus and Disease

Back 97

1. Enveloped DNA viruses, Never been grown in tissue culture

2. Multipliesin liver, which seeds blood with viruses – chronic 107 virions/mL blood, Minuteamounts of blood, blood products; or sexually transmitted, Highincidence among drug addicts Canbecome a chronic infection, Increasesrisk of liver cancer –

Front 98

1. HumanPapilloma Virus: Plantar warts and cervical cancer (DNA)

Back 98

1. 70different types. Transmittedthrough sex. Some of the HPVs can cause genital warts + low risk ofcancer. Sometypes of HPV are linked to cervical cancer. : all cervical cancers arepositive for high risk HPV. HPVinfection can be latent§ Mostpatients are not symptomatic, but can transmit, Plantarwarts -HPV invades the body through tiny cuts orbreaks in skin -bottom of the feet. Virions on contaminated floors of public lockerrooms, showers, swimming pools. Pressurefrom walking causes them to grow deepinto skin.

Front 99

1. Parvovirus: DNA virus, 5thDisease & Canine

Back 99

1. Fifthdisease is caused by infection with humanparvovirus B19. This virus infects only humans. Fifth disease is a mild rashillness that occurs most commonly in children. Pet dogs or cats may be immunizedagainst "parvovirus," A child cannot "catch"parvovirus from a pet dog or cat, Canine parvokills pups.

Front 100

Chapter 25

1. picoRNARhabdovirus: TheBullet:RABIES

Back 100

1. Rabies is fatal, Transmitted by an animal bite thatinoculates the virus into wounds. All mammals susceptible,but carnivores and bats most§ Itdiffers from region to region, dogs are the main reservoir in developingcountries, Rabies virus is negative strand RNA virus with a distinct"bullet" shape

Front 101

1. Filoviruses: Ebolaand Marburg

Back 101

1. Filoviruses include Ebola and Marburg. Fevers-from the mild to the usually fatal. Ebolaand Marburg are particularly deadly and mysterious. Ebolanamed after River in Zaire. - first epidemics occurred in ‘70s. Ebolais classic "emerging disease"- only recently entered human ecology. Theyare becoming increasingly common as human populations grow & climates warm

Front 102

1. Orthomyxovirus Flu & Avian Flu

Back 102

1. RNAinside, a helical capsid, Spherical.The envelope: "spikes” form a halo §Influenza A or B cause epidemics of disease in winter. In the US, illness in 15%of people& 36,000 deaths and 114,000 hospitalizations per year. Gettinga flu shot can prevent illness from types A and B influenza. Type C is mild§Avianflu, swine flus-2 mutations must occur§Humanhost§Transmissionhuman to human

Front 103

1. HIV Infections and AIDS

Back 103

1. Human immunodeficiency virus, Acquired immunodeficiency syndrome, First emerged in early 1980s, HIV-1 may have originated from achimpanzee virus