Week 11 Flashcards
1
Q
What are the 4 characteristics of prokaryotes that distinguish them from eukaryotes?
A
Prokaryotes
- Single-celled, free-living organisms
- Reproduce by binary fission with ss-circular DNA (only have one chromosome)
- Lack intracellular organelles
- Cell membrane = site of respiration
2
Q
What is the gram stain process and what are the ultimate stain colors of gram positive/negative?
A
- Gram Stain
- Cell wall structure determines how stain interacts with the bacterium
- Process: bacteria are fixed to a slide → crystal violet → iodine → alcohol (Gram- are destained) → counter-stain with safranin
- Gram negative: red/pink
- Gram positive: violet
3
Q
What are the three main types of morphology of bacteria?
A
- Morphology
- Coccus – spherical
- Bacillus – rod-like
- Spirillum – squiggly
4
Q
What is a general classification method used to identify bacteria?
A
- Classification: staining → morphology → respiration → grouping (clusters, pairs, spores…) → Genus
5
Q
What are the naming conventions/format of bacteria?
A
- Bacteria are mostly classified according to genus and species
- Names are italicized
- Genus species
6
Q
What are the 5 parts of the bacterial envelope?
A
- Flagella
- Axial filaments
- Fimbriae
- Pili
- Capsule and slime layer
7
Q
For flagella:
- What antigen is a target for drugs/immune system?
- What is the function of the flagella and what forms the flagella?
A
- Flagella
- H antigen (flagellar filament) – target for drugs/immune system
- Propeller for swimming
- Basal body is protein complex between cell wall and cytoplasmic membrane
8
Q
What are the motions of axial filaments?
A
Corkscrew motion
9
Q
What is the function of fimbriae, what gram stain are they more common on, and what type of molecule do they have?
A
- Fimbriae
- Common on Gram- bacteria
- Act as adhesion factor to bind to cell surfaces
- “Lectin” (sugar-binding) function
10
Q
What is the function of the pilus?
A
- Pili
- Transfer of genetic material via “sex pilus”
- Twitching motility on surfaces
11
Q
What is the function of the capsule and slime layer?
A
- Capsule and slime layer
- Coat outer layer of bacteria
- Often an immune escape mechanism, contributing to virulence
12
Q
For the cell wall:
- What is it composed of?
- What is targeted by drugs/immune system? What does this antigen lie on?
A
- Cell wall
- Composed of peptidoglycans
- O antigen (lipopolysaccharides (LPS)) – target for drugs/immune system
- Composed of peptidoglycans
13
Q
What kind of membranes do bacteria have? If relevant, which gram stains have what type of bacteria?
A
- Membrane(s)
- Cytoplasmic (inner) membrane
- Outer membrane (Gram- only)
- Creates periplasmic space
14
Q
Distinguish between gram positive and gram negative with the following:
- Layers (components of these layers)
- Color of gram stain
- Lipid content
- Presence of endotoxins (what endotoxin if relevant)
- Presence of periplasmic space
- Presence of porin channels
- Vulnerability to lysozyme/penicillin attack
- Production of spores
A
15
Q
What is the function of teichoic acid?
A
- In Gram+, teichoic acid activates innate immune system → septic shock
16
Q
What is the function of lipid A?
A
- In Gram-, lipid A (works as membrane anchor for lipopolysaccharide (LPS)) → septic shock
17
Q
What genus is neither Gram+ or Gram-? What susbtance do they carry?
A
- Neither Gram+ or Gram-
- Mycoplasma have no cell wall
- Mycobacterium have complex cell wall structure (TB)
- Mycolic Acid
- Waxy surface does not stain well
18
Q
What is the process of petidoglycan synthesis?
A
- L-lysine on MurNAc attacks peptide bond between two alanine on neighboring MurNAc2 → release of terminal alanine → builds network of sugar-peptide chains
19
Q
What drugs attack the peptidoglycan synthesis?
A
- Penicillin-binding proteins are enzymes that catalyzes these steps
- Ala—Ala peptide bond is site of attack by beta-lactam and vancomycin
20
Q
Define a spore (in terms of bacteria).
What genus are they characterisitic of?
In what situation are they produced?
A
- Spore – a dehydrated, multi-shelled structural form of protection
- Characteristic of Clostridium and Bacillis Gram+ species
- Vegetative cells are bacteria cells that are nutrient deprived → spore-formation
21
Q
What are two important characteristics of spores?
A
- Characteristics
- Highly resistant to degradation
- Dormant (survive for decades)
22
Q
What is the general structure of a spore?
A
- Structure
- Two peptidoglycan layers and outer protein coat
- Dipicolinic acid – high concentration in interior of spore to protect genome
23
Q
Define microbiota.
- Define:
- Normal flora
- Opportunists
- Pathogens
A
- Microbiota – ecological community of microorganisms found in and on our bodies
- Normal flora / indigenous microbiota – peaceful co-existence with our cells
- Opportunists – normally present and cause no disease but capable of causing disease when defenses are breached
- Pathogens – infectious organisms that almost always have potential to cause disease
24
Q
Compare colonization vs infection.
A
- Colonization: presence of community of bacteria with or without evidence of disease
- Infection: invasion/multiplication of microorganisms with may be clinically unapparent or result in cellular injury
- Local infection can lead to disease state
- May become systemic when they gain access to lymphatic/vascular system
25
What are the three things that can occur when you are exposed to a new organism?
* Clearance: no symtoms
* Persistence with no pathology
* Disease state with symptoms
26
In the human body, the flora increase as you...
go down the digestive tract. The stomach barely has any bacteria, while the large intestines has a lot!
27
# Define microbiome and metagenomics.
What things may change the microbiota in our body?
* Microbiome – collective genomes of microbiota at a particular site
* Microbiota differ between healthy individuals and patients
* Vary site-to-site, newborns have simple microbiota, affected by diet/antibiotics
* Metagenomics – study of genetic material from samples
28
Define dysbiosis and what can cause it?
* Dysbiosis – imbalance of host defense factors and bacterial capabilities
* Balance can be perturbed by changes in diet, infection, antibiotic use
29
Define probiotics and what their function is?
* Probiotics – microorganisms administered in attempt to manipulate the microbiota
* Enhances epithelial barrier with increased mucous or defensin production
30
Define prebiotics.
* Prebiotics – nutrients taken to promote maintenance of beneficial microbiota
31
What are three types of chemicals secreted by by epithelial surfaces?
* Provide examples of each type.
* Antimicrobial acids – sapienic acid, linoleic acid
* Defensins – highly charged, cationic peptides that create pores in bacterial membranes and lyse ‘em
* Alpha-defensins – intestinal tract
* Beta-defensins – respiratory tract
* Lysozymes – secreted in mucus, tears, saliva
* Breaks peptidoglycan bonds
* Leads to lysis of bacterial cell
32
What is a mechanism normal flora use to stay alive?
Fimbriae attachment to epithelial cells to prevent secretion
33
What are 4 mechanisms of evasion from macrophages and how do they work?
* Polysaccharide capsule or slime covers bacteria surface to act as camouflage
* Biofilms – aggregation of bacteria bound in polysaccharide/protein matrix
* Sabotage – certain bacteria can block innate response pathway
* *Staphylococcus aureus* produces protein factor.
34
What 3 bacteria species use the sabotage method to evade macrophages and how do they function?
* Salmonella spp. blocks NFkB nuclear translocation
* Yersina spp. sequesters NFkB in cytoplasm
* Bacteroides thetaiotaomicron blocks NFkB ability to transcribe genes
35
What three protein factors are produced by *Staphylococcus aureus?*
* Cytolytic toxins
* Protein A – binds Fc portion of ABs
* CHIPS – chemotaxis inhibitory protein of Staph
36
What are the mechanisms of pathogenic evasion and survival in macrophages of the following bacteria?
* *M. tuberculosis*
* *Listeria monocytogenes*
* *Salmonella sp*.
* *S. aureus*
* *M. tuberculosis* inhibits lysosomal fusion
* *Listeria monocytogenes* escapes the endosome
* *Salmonella sp*. produce factors that modify the phagosome environment
* *S. aureus* produces catalase and superoxide dismutase to neutralize ROS
37
Describe bacterial genomes and what extra choromosomal elements may be involved?
* Bacterial genomes
* Circular, single-stranded DNA
* One chromosome
* Extra-chromosomal elements contain bacteriophages and plasmids
38
What are some mobile DNA elements?
* Mobile DNA elements
* Bacteriophages (extra-chromosomal elements)
* Plasmids (extra-chromosomal elements)
* Insertion and transposon activity mediate “jumping” between sequences of bacteriophages, plasmids, and the chromosome
39
What are the 4 modes of genetic exchange and define each one?
* Modes of genetic exchange: can cause antibiotic resistance
* Transformation – released DNA taken up directly by neighboring cells, integrated by recombination
* Transduction – phages carry DNA to a new cell, either the bacteriophage or pieces of bacterial chromosome
* Conjugation – plasmid or chromosomal DNA is transferred to new cell via sex pilus
* Transposition – gene clusters hop between chromosome, bacteriophage, and plasmid DNAs
40
What is an example of transposition (provided in class)?
* Pathogenicity island – mobile gene cluster carrying functionally related genes
* LEE island on E. coli
41
What are the 4 phases of bacterial growth and what occurs at each step?
* Exponential growth of bacteria (most divide in 20 minutes)
* Lag phase – bacteria adapts to environment with no growth
* Log phase (exponential phase) – bacteria multiplies
* Stationary phase – exhaustion of nutrients with lack of growth; spore formation
* Decline – bacterial death due to exogenous/endogenous reasons
42
In terms of oxygen requirements, define the following:
* Obligate/strict aerobe
* Faculative
* Microaerophilic
* Obligate/strict anaerobe
* Oxygen requirements
* Obligate/strict aerobe – O2 required
* Facultative – growth with or without O2
* Microaerophilic – requires small concentration of O2
* Obligate/strict anaerobe – O2 is fatal
43
Compare and contrast aerobic respiration and anaerobic respiration in terms of ATP and what occurs.
* Aerobic respiration – 38 ATP produced
* Anaerobic fermentation – pyruvate is shunted to produce a variety of C1 to C4 products
44
LIST the 8 types of virulence factors?
CITI(ES)2
* **C**ytolysins
* **I**nvasins
* **T**eichoic acids
* **I**ron scavenging factors
* **E**xotoxins
* **E**ndotoxin
* **S**uperantigen
* **S**ecreted enzymes
45
# Define the following:
* secreted enzymes (in terms of virulence factors)
* invasins
* iron scavenging factors
* cytolysins
* Secreted enzymes – cause tissue damage
* Invasins – bacterial factors that promote penetration into cells
* Iron scavenging factors
* Infection leads to tissue damage → iron leaks out of cell → chemicals released by bacteria with lots of hydroxyl groups bind iron → bacteria take up iron
* Cytolysins – protein on bacterial cell surface that cause cell lysis
46
Define superantigen and what occurs in result?
* Superantigen – bridges T cell receptor and MHC class II without need of antigen
* Uncontrolled immune activation is highly destructive
47
Define endotoxin, what physiology occurs as a result, and provide an example.
* Endotoxin – lipid A in LPS
* Activates innate immune response (fever, leukocytosis, activation of complement, thrombocytopenia, disseminated intravascular coagulation (DIC), shock)
48
# Define exotoxins.
* What roles do the "B" and "A" subunit play here?
* What 4 bacteria have an exotoxin function and how do they each work and what occurs as a result of each one?
* Exotoxins – proteins secreted by bacteria that cause direct cellular and tissue injury (B subunit binds to cell and A subunit causes toxic effect)
* *C. diptheriae*
* Diphtheria toxin blocks EF2, inhibiting protein synthesis
* *V. cholerae*
* Cholera toxin increases cAMP → loss of electrolytes and water → diarrhea
* *C. tetani*
* Blocks end plate inhibitor → continuous stimulation → spastic paralysis
* *C. botulinum*
* Blacks release of ACh vesicle → stimulation blocked → flaccid paralysis
49
Define toxoids.
* Toxoids = inactivated bacterial toxin (vaccines)
50
Define biofilm and Quorum sensing.
* Biofilm – multi-species population enmeshed in a matrix of protein and polysaccharide
* Growth on teeth (dental plaque) and steel
* Quorum sensing – bacteria sense each other’s presence to regulate group behaviors needed for biofilm formation and/or coordinated production of virulence factors
51
Generally, how are bacteria samples cultured?
Several mL of blood are inoculated into liquid broth in bottles and grown until CO2 is detected
Liquid from bottles are placed on plates
52
What is the function of a blood agar plate?
* Blood agar plates: selective agar that reveals hemolysis to identify *Strep* (alpha/beta) or *Enterococcus* (gamma)
53
What is the function of MacConkey agar plates?
* MacConkey agar plates: selective agar that permits only GNRs to grow and differentiates between lactose fermenters (EEK) and lactose non-fermenters (P's and S's)
54
What bacteria are associated with the following infection?
* Otitis Media (ear infection) - 3 types
*Strep pneumoniae, H. flu, Moraxella catarrhalis*
55
What bacteria are associated with the following infection?
* Bacterial Meningitis - 4 types
* Bacterial Meningitis
* *Strep pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Listeria monocytogenes*
56
What bacteria are associated with the following infection?
* Community Acquired Pneumonia (CAP)
* generalized pneumonia (1 type)
* atypical pneumonia (3 types)
* post-influenza pneumonia (1 type)
* Community Acquired Pneumonia (CAP)
* *Strep pneumoniae*
* “Atypical” pneumonias
* *Mycoplasma pneumoniae*
* *Legionella pneumophila*
* *Chlamydophila pneumoniae*
* *Staph aureus* (post-influenza)
57
What bacteria are associated with the following infection?
* Hospital-Acquired Pneumonia (HAP) - 2 types
* Hospital-Acquired Pneumonia (HAP)
* GNRs (*Pseudomonas)*, *Staph aureus*
58
What bacteria are associated with the following infection?
* Abdominal Infections (two classes of bacteria)
* Abdominal Infections
* GNRs AND anaerobes
59
What bacteria are associated with the following infection?
* Non-purulent cellulitis (just erythematous)
* Purulent cellulitis (skin abscesses)
* Cellulitis
* Non-purulent cellulitis (just erythematous)
* Most likely *Strep pyogenes*
* Purulent cellulitis (skin abscesses)
* Either *Staph aureus* or *Strep pyogenes*
60
# Define minimal inhibitory concentration (MIC) and antibiotic suscpetibility testing.
* What is another name for antibiotic susceptibility testing?
* Minimal inhibitory concentration (MIC) – the lowest abx concentration that prevents visible growth
* Antibiotic susceptibility testing – tests an abx’s effectiveness on a bacteria from a particular patient
* Kirby Bauer (disk diffusion)
61
Define bacteriostatic and bactericidal.
* Bacteriostatic – abx that inhibits growth of bacteria
* Bactericidal – abx that kills bacteria
62
What are 5 general mechanisms of bacterial resistance?
* Mechanisms of resistance
* Enzymatic inhibition
* Decreased uptake
* Increased export
* Altered target
* Metabolic bypass
63
Define antimicrobial stewardship.
* Antimicrobial stewardship
* Involves rationing of antimicrobial treatments to slow resistance
64
Which antibiotics are bacteriostatic? There are three main types.
* tetracyclines
* macrolides
* clindamycin
65
Which antibiotics are bactericidal? There are six main types.
* penicilins
* cephalosporins
* vancomycin
* quinilones
* metronidazole
* aminoglycosides
66
Comapre the normal process and the mechanism of action of beta-lactams?
* Normal: transpeptidase (PBP) cleaves alanine-alanine peptide bond of peptidoglycan monomers → peptidoglycan polymer
* Beta-lactam drugs: BINDS to transpeptidase (PBP) and inhibits activity → weakened cell wall of bacteria
67
* What are penicillin toxicities?
* Type I hypersensitivity reaction including mild rash or anaphylaxis
68
* What is a beta lactamase and what is the mechanism of action of beta-lactamase inhibitors (clavulanate, sulbactam, and tazobactam)?
* Beta-lactamase: enzyme produced by staphylococci that cleaves the beta-lactam rings
* Inhibit beta-lactamase and expand coverage to anaerobes and MSSA
69
What are cephalosporin toxicities?
Type I hypersensitivity reaction including rash or anaphylaxis
70
* What are carbapenem toxicities?
* Seizures
* Type I hypersensitivity reaction
71
* What is the mechanism of action of vancomycin?
* BINDS to alanine-alanine motif → blocks transpeptidase (PBP) from binding
72
* How can bacteria resist vancomycin?
* Caused by a change in the peptide component from ala-ala to ala-lactate, which doesn’t allow the drug to bind
73
* What is the mechanism of action of daptomycin?
* Lipopeptide binds to cell membrane → depolarization of membrane → potassium efflux → rapid cell death
74
* What is the mechanism of action of fluoroquinolones?
* Inhibits topoisomerase activity of prokaryotes
75
* What is a potential adverse effect of fluoroquinolones?
* Tendon rupture
76
* What is the mechanism of action of metronidazole?
* DNA Breakage: Absorption of drug allows the formation of a highly active radical that binds to the DNA, destabilizing the DNA.
77
* What is the mechanism of action of 50s subunit inhibitors?
* They do not allow for the fMet-tRNA complex formation, therefore ceasing initiation.
78
* What are potential adverse effects of aminoglycosides?
* Ototoxicity (vertigo or hearing loss)
* Nephrotoxicity
79
* What is the mechanism of action of the tetracyclines?
* Bind to 30s and prevent attachement of aminoacyl tRNA to the A site
80
* What are potential adverse effects of tetracyclines?
* Chelates to bone (teeth staining)
* Phototoxicity
81
* What **three** classes inhibit initiation in protein synthesis?
* Tetracyclines
* Aminoglycosides
* Linezolid
82
* What **two** classes inhibit elongation in protein synthesis?
* Macrolides (azithromycin, clarithromycin)
* Clindamycin
83
* What is the mechanism of action of trimethoprim/sulfamethoxazole?
* Folate synthesis
* Bacteria must synthesize their own folate
84
Gram: +
Bacilli
aerobic
- Listeria
- Bacillus
- Corynebacterium
85
Gram: +
Bacilli
anaerobe
Clostridium difficile/perfringens
86
Gram: +
Cocci
aerobic
catalase: +
coagulase: +
S. aureus
87
Gram: +
Cocci
aerobic
catalase: +
coagulase: -
S. epidermidis
88
Gram: +
Cocci
aerobic
catalase: -
hemolysis: alpha
Strep peneumonia
89
Gram: +
Cocci
aerobic
catalase: -
hemolysis: beta
Strep pyogenes
90
Gram: +
Cocci
aerobic
catalase: -
hemolysis: gamma
enterococcus
91
Gram: -
Cocci
aerobic
(5)
- Neisseria gonorrhoeae (diplocooci)
- Neisseria meningitidis (diplococci)
- Haemophilus influenzae
- Bordetella pertussis
-Moraxella catarrhalis
92
Gram: -
Baccili
anaerobe
B. fragilis
93
Gram: -
Baccili
aerobe
Lactase: +
EEK
- Escherichia coli
- Enterobacter
- Klebsiella
94
Gram: -
Baccili
aerobe
Lactase: -
P's and S's
(PSPSPSPS)
-Psuedoonas
-Proteus
-Providencia
-Salmonella
-Shigella
-Serratia
95
Gram: indeterminate
Baccili
aerobe
Acid Fast: +
Mycobacterium tuberculosis
| (bacillus)
96
Spectrum:
* Gram(+): Strep, Enterococcus, mouth flora
* Gram(-): none
* Other: Spirochetes (Syphilis)
Clinical:
* Strep. Pyogenes (Group A)
* Dental Infection
Natural Penicillin (IV or PO)
97
Spectrum:
* Gram(+): Strep, Enterococcus, mouth flora (methicillin-sensitive staph)
* Gram(-): E.coli, Proteus, H. influenza, (B. fragilis)
Clinical:
* Simple community acquired Gram (-)
Ampicillin/(sulbactam) [iv]
Amoxicillin/(clavulanate) [po]
98
Spectrum:
* Gram(+): Strep, Enterococcus, mouth flora (methicillin-sensitive staph)
* Gram(-): Pseudomonas, Enterobacter, Acinetobacter, (B. fragilis)
Clinical:
* Hospital acquired Gram (-)
* Nosocomial aspiration pneumonia (caused by pseudomonas)
Piperacillin/(tazobactam) [iv]
99
Spectrum:
* Gram(+): staph, strep (MSSA)
* Gram(-): none
Clinical:
* Uncomplicated Cellulitis
Penicillinase – resistant penicillin (methicillin):
* Nafcillin
* Dicloxacillin
100
Spectrum:
* Gram(+): MSSA, beta strep, Strep pneumoniae
* Gram(-): E. coli
Clinical:
* Uncomplicated Cellulitis
* Surgery prophylaxis (heart)
1st Generation
* Cefazolin
* Cephalexin
101
Spectrum:
* Gram(+):MSSA, beta strep, Strep pneumoniae
* Gram(-): Neisseria meningitidis
* Other: Borrelia burgforferi (Lyme)
Clinical:
* Meningitis
* Lyme Disease
3rd Generation (Cross BBB)
* Ceftriaxone
* Cefotaxime
102
Spectrum:
* Gram(+): Broad coverage
* Gram(-): Broad including Pseudomonas
Clinical:
* Nosocomial aspiration pneumonia (caused by pseudomonas)
4th Generation (Cross BBB)
* Cefeprime
103
Spectrum:
* Gram(+): Broad coverage
* Gram(-): Broad including Pseudomonas
Clinical:
* Good for people w/ penicillin allergy
Aztreonam
104
Spectrum:
* Gram(+): staph, streph, Enterococcus faecalis
* Gram(-): Broad
* Other: Anaerobes
Clinical:
* (Broadest Antibiotic)
* Doesn’t treat MRSA
Meropenem
105
Spectrum:
* Gram(+):Broad including MRSA, Enterococcus
* Gram(-): none
Clinical:
* MRSA
Vancomycin
106
Spectrum:
* Gram(+):Broad including MRSA and VRE
* Gram(-): none
Clinical:
* VRE
Daptomycin
107
Spectrum:
* Gram(+): none
* Gram(-): Excellent!
Clinical:
* Only oral drug for pseudomonas
* Complex UTI
* Too strong for most Gram (+)’s
Ciprofloxacin
108
Spectrum:
* Gram(+): strep, staph
* Gram(-): Excellent!
Clinical:
* Only oral drug for pseudomonas
* High Risk Pneumonia
* Complex UTI
* Too strong for most Gram (+)’s
Levofloxacin
109
Spectrum:
* Gram(+): strep, staph
* Gram(-): Excellent!
* Other: Anerobes
Clinical:
* Only oral drug for pseudomonas
* High Risk Pneumonia
* Complex UTI
* Too strong for most Gram (+)’s
Moxifloxacin
110
Spectrum:
* Gram(+): none
* Gram(-): none
* Other: Mycobacteria
Clinical:
* TB
* In combo w/ other drugs b/c of development of rapid resistance
* Accelerates P450 Enzymatic activity of other drugs
Rifampin
111
Spectrum:
* Gram(+): Anaerobes (C. diff)
* Gram(-):Anaerobes
* Other: Protozoa
Clinical:
Metronidazole
112
Spectrum:
* Gram(+): cocci
* Gram(-): none
Clinical:
* Reserved for VRE & MRSA
Linezolid
113
Spectrum:
* Gram(+): MSSA
* Gram(-): H. flu, legionella, moraxella, chlamydia
Clinical:
* Community acquired Resp. tract infection (atypical pneumonia)
* Chlamydia
Azithromycin (Z-pack)
114
Spectrum:
* Gram(+): oral anaerobes, some MRSA
* Gram(-): none
Clinical:
* Oral infection if penicillin allergic
Clindamycin
115
Spectrum:
* Gram(+): none
* Gram(-): broad including multi-drug resistance bacteria (Pseudomonas & Klebsiella)
Clinical:
* LAST RESORT DRUG
* Hearing loss & vertigo
Aminoglycosides
* Gentamicin
* Tobramycin
* Amikacin
116
Spectrum:
* Gram(+): Staph (including MRSA)
* Gram(-): Broad
Clinical:
* THINK TICKS (Rickettsia, Lyme)
* Staph Soft tissue infection
* Chlamydia
Doxycycline
117
Spectrum:
* Gram(+): Staph (including MRSA)
* Gram(-): E. coli
Clinical:
* Pneumocystis jirovecii
* UTIs
* Staph Soft tissue infection
Trimethoprim/sulfamethoxazole
118
**Transmission:** Food and water contaminated with cysts
**Site of Infection:** Colon, Metastatic Liver infection
**Clinical Presentation:** Amebic dysentery: fever, abdominal pain, cramps, bloody stools (RBCs engulfed)
**Epidemology:** N/A
Entamoeba histolytica
119
**Transmission:** Food and water contaminated with cysts
**Site of Infection:** Small Intestine
**Clinical Presentation:** Chronic diarrhea, abdominal pain, bloating, foul smelling stool
**Epidemology:** Most common parasitic illness in USA, Transmission: person-person, daycare centers
Giardia lamblia,
* duodenalis
* intesitnalis
120
**Transmission:** Food and water contaminated with cysts
**Site of Infection:** Small Intestine
**Clinical Presentation:** Chronic diarrhea, abdominal pain, bloating,
**Epidemology:** Uncommon in USA
Cyclospora cayetanensis
121
**Transmission:** Food and water contaminated with cysts
**Site of Infection:** Small Intestine
**Clinical Presentation:** Chronic diarrhea, abdominal pain, bloating,
**Epidemology:** Transmission: daycare center
Cryptosporidium parvum
122
**Transmission:** Sexual Intercourse
**Site of Infection:** Vagina, urethra
**Clinical Presentation:** Usually Asymptomatic, Dysuria from urethritis
**Epidemology:** Worldwide
Trichomonas vaginalis
123
**Transmission:** Sexual Intercourse
**Site of Infection:** Vagina, urethra
**Clinical Presentation:** Usually Asymptomatic, Dysuria from urethritis
**Epidemology:** Worldwide
Trichomonas vaginalis
124
**Transmission:** Triatomine bugs (kissing bugs)
**Site of Infection:** Intracellularly muscle and nerves
**Clinical Presentation:**
* Organomegaly (i.e. cardiomyopathy, megacolon)
* Romaña’s Sign: swelling of eyelid
* Chagoma: ulcer at bite site
**Epidemology:** The Americas (south of the USA)
Trypanosomiasis cruzi (Americas) – Chagas
125
**Transmission:** Tsetse flies
**Site of Infection:** Extracellular
**Clinical Presentation:**
* Lymphadenopathy (Winterbottom’s sign)
* Encephalopathy/ coma
* Chancre: shallow ulcer
* Sleeping sickness
**Epidemology:** Africa, Antigenic Variation of parasite
Trypanosomiasis brucei (African)
126
**Transmission:** Sand flies
**Site of Infection:** Visceral and cutaneous tissues
**Clinical Presentation:**
* Visceral/cutaneous disease of Kala-azar
* Skin ulcers
**Epidemology:** Worldwide except for Australia/Antartica
Leishmania
127
**Transmission:**
* Foodborne (poorly cooked meat)
* Handling of cat feces
* Congenital Transmission
* Organ Transplantation
**Site of Infection:** Tissue cysts in any tissue
**Clinical Presentation:**
* Asymptomatic/limited flu sx in healthy people
* Retinochoroiditis
**Epidemology:** HIV patients can have reactivation
Toxoplasma gondii
128
**Transmission:** Ticks
**Site of Infection:** RBCs (tetrads form)
**Clinical Presentation:**
* Asymptomatic/flu-like sx
* Immunocompromised: anemia
**Epidemology:** Northeast/Midwest USA
Babesia
129
**Transmission:** Anopholes Mosquitoes
**Site of Infection:** Hepatocytes → RBCs → lysed RBCs → anemia
**Clinical Presentation:**
* Malaria
**Epidemology:** Africa, South Asia, Tropical Regions
Plasmodium
130
**Transmission:** Ingestion/penetration of skin
**Site of Infection:** Migratory
* In small intestine
* Travels to bile duct or pancreas
**Clinical Presentation:**
* Intestinal obstruction
* Pulmonary sx
Ascaris lumbricoides
131
**Transmission:** penetration of skin
**Site of Infection:** Migratory
* In small intestine
**Clinical Presentation:**
* Ground itch
* Anemia (attaches to epithelium and sucks blood)
* Bloody stools
* Transient pneumonitis
Hookworm
* Necator americanus
* Ancylostoma
132
**Transmission:** penetration of skin
**Site of Infection:** Migratory
* In small intestine
**Clinical Presentation:**
* Pruritic rash at site of penetration
* Pulmonary sx
* Autoinfection
Strongyloides
133
**Transmission:** ingestion
**Site of Infection:** non-Migratory
* colon/rectum
**Clinical Presentation:**
* Perianal itch
* Most common worm infection is USA
* Insomnia
Enterobius (pinworm)
134
**Transmission:** ingestion
**Site of Infection:** non-Migratory
* colon/cecum
**Clinical Presentation:**
* Painful passage of stool (blood, mucus)
* Rectal prolapse
Trichuris (whipform)
135
**Transmission:** Anopholes Mosquitos
**Site of Infection:** Lymphatic
**Clinical Presentation:**
* Elephantitis
Filaria: wuchreria bancrofti
136
**Transmission:** Flies (Simulium)
**Site of Infection:** Cornea
**Clinical Presentation:**
* River blindness, dermatitis
Filaria: onchocerca volvulus
137
**Transmission:** Flies
**Site of Infection:** Skin
**Clinical Presentation:**
* swelling of skin
Filaria: Loiasis (Loa loa)
138
**Transmission:** Midges and flies
**Site of Infection:** Skin
**Clinical Presentation:**
* dermatitis
Filaria: Mansonellosis
139
**Transmission:** Pork, wild animals
**Site of Infection:** Muscle Tissue
**Clinical Presentation:**
* muscle inflammation
Trichinellosis
140
**Transmission:** Insect bite, Swallowing crustaceans
**Site of Infection:** Blood and Tissue
**Clinical Presentation:**
* Incubated for one year, then NVD
* Blister formation
Dracunculiasis
141
**Transmission:** Solium: Undercooked pork/beef
**Site of Infection:** Migratory tissue cysts from small intestines to bloodstream
**Clinical Presentation:**
* Cysticercosis (formation of cysts)
Taeniasis
142
**Transmission:** Undercooked fish
**Site of Infection:** Small intestines
**Clinical Presentation:**
* Prolonged infection → B12 deficiency (megoblastic anemia)
Diphyllobatrium latum
143
**Transmission:** Sheep (Humans accidental)
**Site of Infection:** Lung and liver
**Clinical Presentation:**
* Asymptomatic, nonspecific
* Anaphylaxis
Echinococcus
144
**Transmission:** Ingestion via anthropods
**Site of Infection:** GI
**Clinical Presentation:**
* Nonspecific
* Nasuea, weakness, abdominal pain, loss of appetite
Hymenolepis nana
145
**Transmission:** Water exposure → penetration of skin
**Site of Infection:** Mesenteric/urogenital veins and super-migratory
**Clinical Presentation:**
* inflammatory reaction
Schistosomes
* hematobium: pelvic vein - hematuria
* mansoni: liver/spleen enlargement, portal hypertension
146
**Transmission:** Undercooked fish/watercrests (water plants)
**Site of Infection:** Small intestine → biliary system
**Clinical Presentation:**
* GI problems
* Biliary obstruction
* RUQ pain
Liver Flukes
* Clonorchis
* Fasciola
147
**Transmission:** Ingestion of undercooked crustaceans
**Site of Infection:** Migratory from GI to lungs
**Clinical Presentation:**
* Egg in sputum sample
* Acute infection
* Mimics TB
Lung Flukes
* paragohomus westermari
148
**Transmission:** Ingestion of water plants
**Site of Infection:** Intestines
**Clinical Presentation:**
* Asymptomatic
* Can lead to infection
Intestinal Flukes
* Fasciolopsis buski
