infectious diseases 2
Terms
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-
viruses consist of either
______or _________ wrapped w/in a protein nucleocapsid - DNA or RNA
- VIRUSES ARE COVERED BY AN ENVELOPE OF _______AND_______
- GLYCOPROTEINS AND LIPIDS
- T/F VIRUSES POSSESS NO METABOLIC MACHINERY
- TRUE
- entirely dependent on host cells for _________and__________and are therefore obligate intracellular parasites
- protein synthesis and replication
- All must attach to receptors on the host cell and achieve entry into the cell through mechanisms that include: (3)
- receptor-mediated endocytosis, fusion, and pinocytosis
- Once within the cells, the virus uncoats, allowing its nucleic acid to utilize host cellular machinery to reproduce (___________) or to integrate into the host cell (___________).
-
productive infection
latent infection - influenza virus, cause disease by ________of infected cells
- lysis
- _____________, do not directly cause cell destruction but may involve the host immune responses in the pathogenesis of disease
- hepatitis B virus
- _____________, promote neoplastic transformation of infected cells
- human T-lymphotropic virus type 1(HTLV-1)
- By multiplying within host cells, viruses can avoid ____________antibodies
- neutralizing
- Some viruses can spread to uninfected cells by
- intercellular bridges
-
viruses capable of persisting latently for prolonged periods
(2) -
HSV
HIV - CAPABLE OF GENE REARRANGEMENT
- INFLUENZA
- ___________ : proteins that are responsible for a number of progressively fatal neurologic diseases in humans, such as kuru, Creutzfeldt-Jakob disease (CJD), and familial fatal insomnia, and animal diseases such as scrapie and bovine spongiform encephalo
- PRIONS
- Prions are encoded by
- host genes
- some prion diseases (e.g., familial CJD) are ________, others, including kuru and new variant CJD are acquired through consumption of infected ____________. There is no known treatment for these disorders
-
inherited
neural tissue - varied group of organisms that are generally capable of cell-free growth, although some produce disease as intracellular parasites
- BACTERIA
- COMMON STD CAUSED BY A BACTERIUM WHICH CAN DAMAGE A WOMAN'S REPRODUCTIVE ORGANS
- CHLAMYDIA TRACHOMATIS
- S/S OF CHLAMYDIA IN MALES
- DISCHARGE FROM PENIS
- T/F CHLAMYDIA CAN CAUSE "SILENT" INFERTILITY BEFORE A WOMEN RECOGNIZES THE PROB
- TRUE
-
MOST FREQUENTLY REPORTED STD
IN 2004= 929,462 REPORTS - CHLAMYDIA
- HOW MANY PEOPLE ARE INFECTED W/ CHLAMYDIA EACH YEAR?
- 2.8 MILLION
- Chlamydiae are also obligate intracellular parasites; they always contain both DNA and RNA, divide by ___________(rather than multiplying by assembly
- binary fission
- Chlamydia trachomatis causes _________, the major cause of _____________in the developing world, and a variety of sexually transmitted genitourinary disorders
-
trachoma
blindness - Chlamydia pneumoniae is a common cause of :(3)
-
atypical pneumonia, bronchitis,
sinusitis - the cause of a common infectious disease of birds, can produce a serious systemic illness with prominent pulmonary manifestations in humans
- Chlamydia psittaci
- Chlamydiae are susceptible to ________AND ________ antibiotics
- tetracyclines and the macrolide
- obligate intracellular parasites. They are primarily animal pathogens that generally produce disease in humans through the bite of an insect vector, such as a tick, flea, louse, or mite
- Rickettsiae and ehrlichiae
- With the exception of Q fever and human ehrlichiosis, _________________is a prominent manifestation of these often disabling febrile illnesses
- rash caused by vasculitis
- Rickettsiae and ehrlichiae are susceptible to:
- tetracyclines and chloramphenicol
- smallest free-living organisms and have no cell walls
- MYCOPLASMAS
- Mycoplasma pneumoniae is an agent of (2)
- pharyngitis and pneumonia
- primarily agents of genitourinary disease
- Mycoplasma hominis Ureaplasma urealyticum
- Mycoplasmas are sensitive to
- erythromycin, tetracycline
- organisms that are not readily seen under the microscope unless stained with silver or viewed under darkfield illumination
- SPIROCHETES
- 4 genera of spirochetes cause disease in humans. Treponema species include the pathogens of :
-
YAWS
PINTA
BEJAL
SYPHILIS - The illnesses caused by these organisms are chronic and characterized by:
- prolonged latency in the host
- t/f Penicillin is active against Treponema.
- TRUE
- LEPTOSPIRA CAUSES:
- ACUTE AND SUBACUTE FEBRILE ILLNESSES
- BORRELIA ARE ARTHROPOD BORNE THAT CAUSE:
- LYME DISEASE
- organisms that cannot grow in atmospheric oxygen tensions
- ANAEROBES
- cause well-defined systemic illnesses such as food poisoning, tetanus, and botulism
- Clostridium
- Clues to the presence of anaerobic infection include (2)
-
(1) a foul odor
(2) the presence of gas, which may be seen radiographically - Many pathogenic anaerobes are sensitive to penicillin. exceptions are:
- Clostridium difficile, which is almost always sensitive to metronidazole and vancomycin
- pink on a properly prepared Gram stain
- gram negative bacteria
- Gram-negative bacteria are the most common cause of:
-
cystitis
pyelonephritis - Haemophilus species are common pathogens of the respiratory tract and cause:
- otitis media, sinusitis, and pneumonia
- cause of meningitis, particularly in children
- Haemophilus
- Except for Haemophilus species, ___________are uncommon causes of community-acquired pneumonia but are common causes of nosocomial pneumonia.
- gram-negative bacteria
-
Enterobacteriaceae include:
(these are large gram - rods) -
Escherichia coli,
Klebsiella,
Enterobacter,
Serratia,
Salmonella,
Shigella,
Proteus - The Enterobacteriaceae can be thought of as ____________
- gut-related or genitourinary pathogens
- cause of enteritis
- salmonella
- agent of bacterial dysentery
- shigella
- can cause staghorn calculi (renal stones)
- proteus
- gram neg cocci
- neissaria and moraxella
- Neisseria meningitidis is an important cause of _______, and Neisseria gonorrhoeae causes _________
-
meningitis
gonorrhea - appear deep purple on Gram stain
- GRAM-POSITIVE BACTERIA
- can infect any organ system. It is a common cause of bacteremia and sepsis. The organism often colonizes the anterior nares
- staph aureus
- Hospital workers colonized with S. aureus have been responsible for __________
- hospital epidemics
- Staphylococci tend to form ____________
- abscesses
- Staphylococcal toxins also mediate the scalded skin syndrome and the multisystem manifestations of :
- toxic shock syndrome
-
GRAM + BACTERIA:
INCREASING PROPORTION IS _____ RESISTANT
_________REMAINS ACTIVE -
PEN
VANCOMYCIN - CAUSES UTI'S
- S SAPROPYTICUS
- CAUSES SKIN INFECTIONS AND PHARYNGITIS
- STREPTOCOCCI
- the most common cause of bacterial pneumonia and an important cause of meningitis and otitis media; use high dose PCN
- strept pneumoniae
- acid fast and retain dye when washed
- mycobacteria
- slow-growing (some require up to 6 weeks to demonstrate growth on solid media), obligate aerobes
- TB
- an important cause of disseminated infection among patients with AIDS
- M. avium complex (MAC)
- disease of skin and peripheral nerves
- leprosy
- produce osteomyelitis and abscess, pneumonia
- Nocardia and Actinomyces
- tx Nocardia w/:
- sulfonamides
- oval yeasts that often colonize the mouth, gastrointestinal tract, and vagina of healthy individuals
- CANDIDA
-
may produce disease by overgrowth and/or invasion.
_______often occurs in individuals who are receiving antibiotic or corticosteroid therapy - Candida stomatitis (thrush)
-
FUNGI COMMONLY CAUSE:
CANDIDA IN THE BLOOD CAN CAUSE: -
YEAST INFECTIONS
SEPSIS - Mucosal candidiasis can be treated with
- fluconazole
- fungus endemic to the Ohio and Mississippi River valleys. Mild febrile syndromes tx w/ ____________
-
Histoplasma capsulatum
amphotericin B - most common clinical manifestation of infection with this fungus is a chronic meningitis; seen in immunocompressed
- Cryptococcus neoformans
- mold that causes pneumonia
- aspergillus
- This organism causes life-threatening pneumonia in patients with impaired cell-mediated immunity; it is the most common major opportunistic pathogen in persons with AIDS
- Pneumocystis carinii
- Diseases caused by __________are among the most prevalent diseases in the developing world but are uncommon causes of illness in North America.
- helminths
-
HELMINTHS
HOOKWORMS CAUSE:
PINWORMS CAUSE: -
GI BLOOD LOSS
ANAL PRURITIS
- SCOTCH TAPE TEST - as a result of infection from a microbial parasite, pathological harm to the host becomes evident
- infectious disease
- groups of host defense mechanisms:
-
1. constitutive
2. inducible -
common to all healthy animals; provide general protection;
~"natural or innate" resistance - constitutive
-
defense mechanism that must be induced; not immediate after host is exposed to parasite
involves the immune responses to pathogen causing infection - inducible
-
skin and mucosal surfaces;
cough and gag reflexes to expel aspirated secretions;
chemical agents such as acids and defensins with antimicrobial properties. - ANATOMIC DEFENSES
- These defenses are primarily located at sites with proximate environmental contact
- ANATOMIC DEFENSES
- interference with anatomic defense mechanisms may increase the risk of:
- infection
- One of the most important of these humoral defenses is the
- complement system
- Complement activity results from the sequential interaction of a large number of:
- plasma and cell membrane interactive proteins.
- The classic complement pathway is activated by:
- antibody-coated targets or antigen-antibody complexes
- COMPLEMENT ENZYMES ARE INVOLVED IN:
-
-LYSIS OF CERTAIN BACTERIA, VIRUSES, AND OTHER MICROORGANISMS
-PHAGOCYTIC CHEMOTAXIS
-OPSONIZATION
-INFLAMMATORY RESPONSE - Ig_ AND _ CAN "FIX COMPLEMENT" B/C OF A BINDING SITE ON THE Fc
-
IgG
IgM - IgG AND Ag "CASCADE REACTION"
-
1. generate inflammatory factors(C3a, C5a)
2. attract phagocytes
3. enhance phagocytic engulfment
4. lysis of bacterial cells or virus infected cells - Persons with complement deficiencies, particularly deficiencies in terminal components, are especially at risk for repeated infections with gram-negative encapsulated bacteria, especially _________species.
- Neisseria
- large Y shaped protein
- antibody
- antibodies are used by the ________system to identify ________and________
-
immune system
bacteria and viruses - production of antibodies is the main function of:
- humoral immune system
-
immunoglobins are
-found in:
-synthesized and secreted by: -
blood,tissue fluids,secretions
plasma cells that are derived from B cells - B cells are activated upon binding to their specific antigen and differentiate into
- plasma cells
- cells that ingest microorganisms via phagocytosis; also involved with _______
-
phagocyte
apoptosis - phagocytes are useful in ________ RESPONSE TO TISSUE DAMAGE
- IMMUNE SYSTEM
- T cells are a type of ______that play a role in __________
-
WBC
CELL MEDIATED IMMUNITY - PART OF THE INNATE IMMUNE SYS; ATTACK CELLS INFECTED BY MICROBES, BUT NOT MICROBES THEMSELVES
- NATURAL KILLER CELLS
- PROTEINS PROD BY IMMUNE SYS IN RESPONSE TO VIRUSES, BACTERIA, PARASITES, AND TUMOR CELLS
- INTERFERONS
- INTERFERONS BELONG TO TO THE LARGE CLASS OF ______KNOWN AS ________
-
GLYCOPROTEINS
CYTOKINES - IMMUNE RESPONSE NOT INVOLVING Ab BUT MACS AND NK CELLS, AG SPECIFIC T LYMPHOCYTES, AND RELEASE CYTOKINES
- CELL MEDIATED IMMUNITY
-
BRANCH OF IMMUNE SYS W/
PROTECTIVE FX FOUND IN SERUM:
ASSOC W/ CELLS: -
HUMORAL
CELLULAR -
Streptococcus pneumoniae
The type-specific polysaccharide capsule is a major virulence factor because of its __________properties - antiphagocytic
- T/F In the absence of immunity, pneumococci reaching the alveoli are not effectively contained by the host
- TRUE
- ___________ of s. pneumo promotes oxidative burst activity causing destruction of the organism
- Opsonization
- Capsular polysaccharide also represents an important virulence factor for meningococci
- Neisseria meningitidis
- pathogenic Neisseria species produce an ___ protease that dissociates the ___ molecule;
-
IgA
IgA - patients lacking__________ are suceptible to meningococcal infection
- C6, C7, or C8
- escape intracellular digestion by secreting products that inhibit phagolysosomal fusion
- MYCOBACTERIUM TUBERCULOSIS
- any agent that can cause trouble to the immune sys
- pathogen
-
first line of defense against dz. not directed at particular pathogen:
defend against particular pathogen: -
nonspecific
specific - most important nonspecific defense
- skin
-
tissues that protect the interior surfaces of body;
sticky fluid that traps pathogens -
mucous membranes
mucus - trap viruses and bacteria in nose and throat
- mucus, cilia, hairs
- enzyme breaks down cell wall of bacteria
- lysozyme
- most common phagocyte (WBC)
- neutrophil
- substance that triggers the specific defenses of the immune sys
- antigen
- organs involved in immune response
-
bone marrow
thymus
lymph nodes
tonsils
adenoids
spleen -
manufactures WBCs:
filter pahtogens from lymph:
filters pathogens from blood: -
bone marrow
lymph nodes
spleen -
T cells mature in _______
_____ directly kill invaders
_____ help B & T cells -
Thymus
Cytotoxic Ts
Helper Ts -
B and Ts develop capability to prod Abs:
response to similar antigen is faster b/c B cells remember: -
primary response
sedondary response -
can det harmful or not and self from nonself:
no central control:
infinite possible Abs:
remembers antigens:
nonused cells are discarded, new cells created continuous: -
Recognition
Distrib.& Self Regulate
Diversity
Learning & Memory
Metadynamics -
TESTS FOR PRESENCE OF CRYPTOCOCCUS *MOST COMMON CNS FUNGUS*
causes pneumonia and can cause meningitis; seen in immunocompressed - INDIA INK
- DET PRESENCE OF FUNGI IN SKIN, NAILS OR HAIR
- KOH PREP
- Herpes blister scrapings are placed on a glass slide, air dried, and stained with Wright stain
-
TZANCK PREPARATION
"TZANCK god i don't have HERPES" - herpes background looks like ground glass and has dark spots called ________
- inclusion bodies
-
Diseases Often Diagnosed by Detection of Microbial Antigens:
Meningitis
Resp tract infection
GU tract infection
Hep B -
Latex agglutination
Immunoflourescence
Enzyme immunoassay
Radioimmunoassay -
Examine Host Response:
PMN's
Lymphocytic infiltrates
Eos
Granulomas -
Acute Bac.Infection
Virus,Fungal, and mycobac.
Helminthic infection
Fungal Infection - all viral pathogens that can be cultured require ___________in which to grow
- eukaryotic cells
-
**Strep Pneumo**
H flu
Less common: Staph, strep pyogenes, pseudomonas, moraxella - acute sinusitis
- bacteria causing CAP
- strep pneumo
-
Hepatitis
liver complications:
pregnancy risk:
fecal-oral:
Has vaccine: -
C
E
A,E
A,B - Chronic Hep C tx:
-
Interferon
Ribaviron - Gram negative bacteria that form a normal part of the human flora. They are a frequent cause of _________in children.
- endocarditis
- HACEK
-
Haemophilus aphrophilus and Haemophilus paraphrophilus
Actinobacillus actinomycetemcomitans
Cardiobacterium hominis
Eikenella corrodens
Kingella kingae -
normal bac flora in
skin
nose
mouth
plaque -
skin - staph epidemidis
nose - staph aureus
mouth - streptococci
plaque - strept mutans -
normal flora for
gingival crevices:
throat:
colon:
vagina: -
gingiva - anaerobes
throat - streptococci
colon - fragilis, E coli
vagina - bacillus, E coli - The classical triad of meningitis are:
- fever, headache, and nuchal rigidity ("neck stiffness")
- Bacterial meningitis is usually caused by:
- **Streptococcus pneumoniae and Neisseria meningitidis
- a medical history, a chest X-ray, and a physical examination. It may also include a skin test, a serological test, microbiological smears and cultures
- dx tests for TB
- Transmission occurs most commonly through blood and blood products, contaminated needles, and sexual contact. High-risk transmission groups include the following: sexual partners of acutely and chronically infected persons, with male homosexuals being at
- HBV
- isoniazid, rifampicin, pyrazinamide and ethambutol for two months, then isoniazid and rifampicin alone for a further four months
- tx for TB
- Rheumatic fever Jones Criteria
-
JONES crITERIA:
· Major criteria:
Joint (arthritis)
Obvious (Cardiac)
Nodule (Rheumatic)
Erythema marginatum
Sydenham chorea
· Minor criteria:
Inflammatory cells (leukocytosis)
Temperature (fever)
ESR/CRP elevated
Raised PR interval
Itself (previous Hx of Rheumatic fever)
Arthralgia - to dx RF, Need 2 major or 1 major and 2 minor criteria, plus evidence of recent ___infection
- GAS
- mnemonic that can be used to remember the bacteria that cause UTIs is SEEK PP
- Staph saprophyticus, E. coli, Enterococcus, Klebsiella, Proteus, Pseudomonas
-
Lyme Dz. symptoms
1.Acute(early)
2.Chronic -
1.Erythema migrans rash
2. Bell's Palsy or meningitis
3. Recurrent arthritis - Rocky Mountain spotted fever is the most severe and most frequently reported ________illness
- rickettsial
- If allergic to PCN, use:
-
clindamycin
azithromycin
clarithromycin - Some studies reported a correlation between use of aspirin or other salicylates in children and adolescents who have a viral infection such as influenza or chicken pox and causes liver failure
- Reye's syndrome
-
these bact are assoc w/:
botulinum
C perfringen -
clostridium botulinun dz
gas gangrene seen on x-rays -
vaccine for hep B
hep A -
0,3,6 mo
0,6 mo - 10 mil cfu/ml
- Bacteremia
- + leukocyte esterases suggests
- UTI
- Gram - causes ______in hospital pts
- sepsis
- ______ are resistant to gram stains.
- mycobacterium
-
early stage tx: doxycyclin, amoxacillin, cefuroximine, clarithromyacin, azithromyacin
Tx = 14-21 days
late state tx: ceftriaxone 3rd gen cephalosporine - tx for Lyme dz
- dental extraction in high risk pt w/ bacterial endocarditis tx w/
-
amoxicillan or a macrolide: erythromycin
azithromycin (Zithromax®)
clarithromycin (Biaxin®)
dirithromycin (Dynabac®)
roxithromycin (Rulid®, Surlid®) - __________ has replaced pcn and ampicilin for tx of gonorrhea
- ceftriaxone
- Chlamydiae are susceptible to:
- tetracyclines and the macrolide antibiotics(azithromycin)
-
how do you get g- salmonella/shigella
tx: -
water, food, fecal oral, and sex
tx = bactrim or fluoroquinolone -
immunocompromised
advanced age
alcohol - risk factors for CAP
- immunocompetent are recommeded to get pneumovac at age ___ every _____yrs
-
65
6 - causes nosocomial hospital acquired pneumonia
- staph
-
prob cause of septic arthritis of one joint in young female
labs: -
gonococcal
joint tap - # 1 cause of bac meningitis in a kid < 1
- s pneumo
-
immunoglobin assoc w
early response:
mast cell and paracytic infx: -
IgM
IgE - Silver stain for ________ and tx with _________
-
PCP in aids pts
tx = bactrim - walking pneumo causes
- chlamydia and mycoplasm
- tx of C Difficile:
-
1. flagyl (AKA Metronidazole)
2. vancomycin
3. stool transplant ? -
With the exception of aminoglycosides and certain azalide and macrolide antibiotics, agents (TCN) inhibiting protein synthesis at ribosomal sites are generally ___________.
_______ destroy the cell wall
ex: PCN -
bacteriostatic
bactericidal -
bacteriostatic
buy AT 30s:
CEll at 50s: -
30:aminoglycosides
tetracyclines
50:clarithromycin chloramphenicol, clindamycin, erythromycin -
fever >101 for 3 wks.
>105.5 -
FUO
hyperthermia -
name the cause
Q fever:
Lyme dz:
Toxoplasmosis from cat feces:
Leptospirosis from urine of infected dogs, cats, animals:
Brucellosis/Undulant fever: -
coxiella burnetii
borrelia burgdorferi
toxoplasma gondii
leptospira interrogans
brucella (cattle,pigs,goats unpasteurized dairy prods) -
causes of
malaria
TSS
syphilis and tx -
plasmodium
staph aureus
treponema pallidum
tx 2.4 mill Units of PCN - measles assoc with _____ spots:
- copplex spots
-
most common opportunistic pathogen in persons w/ AIDS:
seen in SW;produces pneumonia in immunocompromised pts;
treat w/ ampho B: -
PCP
coccidioides immitis -
Name the organism;
obligate intracell parasite,
always have DNA and RNA,
divide by binary fission,
depend on host for survival:
leading cause of blindnes in developing world: -
chlamydiae
C. Trachomatis -
Name the bacteria;
toxin mediates the multi system manifestations of TSS,
Abcess formers:
G - causes renal stones: -
Staph aureus
Proteus - prion dz acquired from consumption of infected neural tissue
- Kuru
-
Pneuococcus is assoc w/ what color sputum?
Rice water stools are assoc w/ which pathogen? -
rusty
vibrio cholerae - plague causing organism uses rodents and prairie dogs as its vector:
- Yersinia Pestis
-
this animal kills the most humans worldwide:
preferred tx for pneumococcal pneumonia? -
mosquitos
PCN G or 3rd gen cephalosporin -
agar in which N gonorrhea is grown on?
tx for gonococcal urethritis: -
chocolate
250mg IM ceftriaxone
100mg doxycycline po x 7d - Antibodies are large polypeptides that are produced by B lypocytes and plasma cells which may facilitate ingestion of the microbe by phagocytes in a process named?
- opsonization
-
name the Ig;
role in allergy by triggering mast cell activation,mediates responses in parasitic infections:
comprises the earliest immune response:
most prevelent in blood: -
IgE
IgM
IgG -
people w/ complement deficiencies are at risk for repeated infections w/ which bug?
woman + gonorrhea, + painful cervicitis present w/ what sign? -
Neisseria
chandelier sign - _________ means eating cell from greek word 'phagein'
- phagocytosis
-
grey baby
red man syndrome
orange-red urine, tears -
chloramphenicol
vancomycin
rifampin -
pseudomembranous colitis
tx leprosy -
clindamycin
dapson -
butterfly appearance
rash on hands -
SLE
syphilis -
SW
MISS AND OHIO RIVER VALLEYS
STATES EAST OF MISS RIVER AND CENTRAL AMERICA -
COCCIDIOIDOMYCOSIS
HISTOPLASMOSIS
BLASTOMYCOSIS