Cumulative Final Exam Flashcards
1
Q
What is PK?
A
What our bodies do to the antimicrobrials
Absorbtion, Distribution, Metabolism, Excretion
2
Q
What is PD?
in regards to microbiology
A
What the antimicrobrials do to the pathogen
links drug exposure to microbiological and/or clinical effect
3
Q
Gram Positive
Staphylococcus Coagulase (-) Organisms
Catalase + “clusters”
A
S. Epidermis
S. Saprophyticus
S. lugdunesis
S. Haemolyticus
S. Hominis
S. Warneri
Commonly live on human skin
4
Q
Gram Positive
Staphylcoccus Coagulase (+) Organisms
Catalase + “clusters”
A
S. Aureus
important
note: MRSA is methicillin-resistant staph aureus
5
Q
Gram Positive
Streptococcus Hemolysis α Organisms
Catalase - “pairs/chains”
A
S. pneumoniae
there are others but we never rlly discussed
6
Q
Gram Positive
Steptococcus Hemolysis γ Organisms
Catalase - “pairs/chains”
A
Enterococci:
- E. Faecalis
- E. Faecium
Group D Strep
7
Q
Gram Positive
Streptococcus Hemolysis β Organisms
Catalase - “pairs/chains”
A
Group A Strep = S. pyogenes
Group B Strep: S. agalactiae
Group C/G Strep = S. Dysgalactiae
8
Q
Gram Negative
Enterobacterales Organisms
A
Escherichia spp.
Klebsiella spp.
Plesiomonas spp.
Enterobacter spp.
Citrobacter spp.
Salmonella spp.
Shigella spp.
Proteus spp.
Providencia spp.
Serratia spp.
Edwardsiella spp.
Yersinia spp.
Morganella spp.
Hafnia spp.
9
Q
Gram Negative
Lactose Fermenting Spot Indole (+) Organisms
A
Escherichia coli
Klebsiella oxytoca
10
Q
Gram Negative
Lactose Fermenting Spot Indole (-) Organisms
A
Enterobacter cloacae
Citrobacter freundii
Klebsiella aerogenes
Klebsiella pneumoniae
11
Q
Gram Negative
Non-Lactose Fermenting Oxidase (+) Organisms
A
Pseudomonas
Vibrio
Aeromonas
Flavobacterium
Alcaligenese
Plesiomonas
Chromobacterium
12
Q
Gram Negative
Non-Lactose Fermenting Oxidase (-) Organisms
A
Acinetobacter
Salmonella
Shigella
Serratia
Edwardsiella
Yersinia
Morganella
Hafnia
13
Q
Gram Stain Tells us
Determines Cell Wall Form
A
gram positive: stains purple
gram negative: stains pink/red
other: stains clear
14
Q
Gram Stain Tells us
Determines morphology (shape)
A
cocci, bacilli, or other
15
Q
Gram Stain tells us
Acceptability of specimen
A
If site is non-sterile than other organisms will likely present
16
Q
Gram Stain Tells us
Quantification of Bacteria
A
is there a lot of bacteria? or not too much?
a lot of WBC= infection
a lot of epithelial cells= bad sample
17
Q
What is Bactericidal?
A
Kills organism through the action of antimicrobrial
18
Q
What is Bacteriostatic?
A
Halts organism growth through the action of the antimicrobrial
19
Q
Is Bacterio- static or -cidal better?
A
Depends on the concentration!
- Low concentrations of -cidal drugs can be -static
- High concentrations of -static drugs can be -cidal
20
Q
What is Broad Spectrum Activity?
A
Antimicrobrial targets many types of pathogens
21
Q
What is Narrow Spectrum Activity?
A
Target only a few types of pathogens
22
Q
What is Empiric Antimicrobrial therapy?
A
therapy that is started before pathogen and susceptibility are known because
- culture results are nto available/complete
- antimicrobrial susceptibility is not known
23
Q
What is Definitive Antimicrobrial therapy?
A
Therapy that is started after pathogen and susceptibility is known. AKA “directed therapy” or “step-down therapy”
24
Q
Frequent Blood Culture Contaminants
A
Staph Epidermis: skin cells
Corynebacterium spp.
Bacillus spp.
Cutibacterium acnes
Micrococcus spp.
Common skin cell contaminants when we see these we don’t always treat
25
NEVER Blood Culture Contaminants
| always represent true infection
Staph aureus, Staph lugdunensis, Gram-negatives, some anaerobes, Yeast
| ALWAYS TREAT THESE ORGANISMS
26
What to consider when there is a blood culture contaminant
- What is the clinical status of patient? Do they seem sick?
- Is this a common contanimant?
- Do they have an indwelling medical device
- Repeat the culture in another location - is the contaminant still there?
- Is it taking a long time for the organisms to grow?
- Are all the blood culture bottles positive?
27
What is Antimicrobrial Resistance?
The antimicrobiral concentration below that MIC at which a typical patient will usually respond given a typical dose
| pathogens gain the ability to not be killed by drugs at safe doses
28
Intrinsic Resistance
Natural resistance of microbes to antimicrobrials
| Resistance microbes are born with and is always expressed within species
29
Acquired Resistance
Obtained resistance of microbes to antimicrobrials -
Resistance microbes obtain to antimicrobials they were prevously susceptible to
30
# big purple chart
Methicillin-resistant Staphylococcus Aureus Treatments
Vanc (+13), Dappin up Lids, Caroline D'alba, Teleports Over Prissy Tigers& Teachers, Temporarily Clinching Rifle Delays
31
# big purple chart
Vancomycin-resistant Enterococci Treatment
Dappin up Lids Over Prissy TIgers& Frostbite Nights
32
# big purple chart
Atypicals Treatment
Fuck My Teachers
| lol not actually
33
# big purple chart
P. Auruginosa Treatment
Piper Aztec Amber Loves Delays ,
Polly Cips Cefs & Carbs
34
# big purple chart
Anaerobe Treatment
Piper Aims Amps ox&teet Carb Make Metro Tigers Delay
35
# big purple chart
Carbapenem-resistant Enterobacterales Treatment
| Only drug that treats this one and not others
Meropenem-vaborbactam
36
# big purple chart
pAMPC- Type Cephalosporinase Producing Organisms Treatment
| ones that only treat amp c
Cefepime and TMP-SMX
37
# bIg purple chart
Extended Spectrum Beta Lactamase Producers Treatment
| ones that only treat ESBL
Ceftolozane-tazobactam, Nitrofurantoin, Fosfomycin
38
# big purple chart
Treats ESBL and AmpC
Carbapenems/BLI and Fluoroquinolones
39
# big purple chart
Treats ESBL, AMPc, and CRE
| only ones that treat all 3
Polly & Amber Cef Tigers
40
What is Zone of Inhibition?
qualitative way to measure the activity of drug. organism grows on top of media and antibiotic diffuses on plate for 18-24 hours
↑zone of clearance = ↑antimicrobial activity
41
What is MIC?
Lowest concentration of given antimicrobial that will inhibit the visual growth of an organism after 18-24h incubation.
↓ MIC = ↑ antimicrobial activity
42
4 Methods of Susceptibility Testing
**Qualitative:**
1. Disk Diffusion
**Quantitative: **
2. Broth Dilution
3. Etest (agar diffusion)
4. Automated susceptibility testing
43
What is the relationship between zone of inhibition and MIC
Inverse relationship
↓ MIC = ↑ zone of inhibition
44
# Susceptibility
Susceptible Interpretation
antimicrobrial concentration is ABOVE the MIC
45
# Susceptibility
Intermediate Interpretation
antimicrobrial concentration is close to the MIC
46
# Susceptibility
Resistant Interpretation
antimicrobrial concentration BELOW the MIC
47
What are Local Antibiograms?
Overall antimicrobrial susceptibility profile of specific microorganisms to various antimicrobrials (typically at your hospital)
Informs the clinician of local institutional patterns and thus inform empiric antimicrobrial precribing patterns while we wait for culture results
| ↑ percentage = ↑ susceptible
48
What does MRSA mean?
Methicillin-resistant Staphylococcus Aureus
OR Nafcillin OR Oxacillin
49
What does MSSA mean?
Methicillin-susceptible Staphylococcus Aureus
OR Nafcillin OR Oxacillin
50
What does it mean if resistance report says: "S. aureus, mecA positive or PBP2a"
MRSA
51
Enterococcus Faecalis vs. Enterococcus Faecium
Faecalis is more common and less drug resitant
Faecium is less common and more drug resistant
52
Enterococcus Faecalis Treatment
Ampicillin
53
Streptococcus Pyogenes Treatment
Penicillin
**has absolutely no resistance to penicillin**
| ~gram positive~
54
Necrotizing Faciitis Treatment
Cell wall active agent (penicillin) plus toxin-inhibiting antibiotic (clindamycin)
55
Streptococcus Pneumoniae Treatment
- Penicillin
- 3rd Gen Cephalosporins: cefdinir, ceftriaxone, etc.
- Fluoroquinolones
- Vancomycin (highly resistant strains)
- Vaccines: PCV13 (prevnar) and PPV23 (pneumovax)
| ~gram positive~
56
Clostridioides Difficile Treatment
**Oral Vancomycin**
and discontinue offending antibiotic
- fidaxomicin
- metronidazole
- fecal transplant
57
C. diff risk factors
- exposure or previous history
- older age
- recent hospitalization
- immunocompromising conditions
- **CLINDAMYCIN**
- fluoroquinolones, carbapenems, 3rd/4th gen cephalosporins
| C. diff is gram positive
58
Enterobacterales Treatment
varies with type/severity of infection, patient history, abx susceptibility
- pipercillin/tazobactam
- ceftriaxone
- cefepime
- carbapenems
- fluoroquinolones
- nitrofurantoin
59
What is the most common Gram (-) Non-lactose fermenting organism?
Pseudomonas aeruginosa
| found in skin/soft tissue, urinary tract, & eye/ear infections
60
Yeast is divided into:
Candida Species and Cryptococcus Species
61
What are the candida species?
C.:
albicans, glabrata, parapsilosis, tropicalis, krusei, lusitaniae
62
What are the cryptococcus species?
C. neoformans
63
What are the Dimorphics?
Coccidoides immitis, Blastomyces dermatidis, Histoplasma capsulatum
64
What are the Molds?
Aspergillus fumigatus, Zygomycetes (Mucor), Fusarium spp., Scedosporium spp.
| Fuck (fusarium)
Zach's (zygo)
Ass (asp) has
Skid marks (sced)
65
What are primary yeast pathogens?
can infect otherwise normal and healthy hosts
66
What are opportunistic yeast pathogens?
typically require "abnormal/immunocompromised" hosts to establish infection
ex: Candida spp. or Cryptococcus neoformans
67
Which is the most prevalent fungal infection?
Candida albicans
- associated with UTI's, candidemia, CNS candidiasis, endocarditis
68
Risk factors for Invasive Candidiasis
immunosuppression, central venous catheters, surgery, paranteral nutrition, neutropenia, renal replacement therapy in ICU, implantable prosthetic devices, broad spectrum antibiotics
69
Candida spp. Oropharyngeal Infections
AKA thrush
- typically caused by C. albicans
- Sx: white patches in mouth
- Tx: swish and swallow and rinse mouth after ICS
70
Candida spp. Vulvovaginal Infections
AKA yeast infection
- Sx: itching, redness, irritation, cottage cheese discharge
- Tx: "One and done" dose of fluconazole!
| we familiar unfortunately
71
Candida spp. UTI
AKA Candiduria (rare compared to bacterial UTI)
- Sx: cystitis, blood in urine
- Dx: symptoms and urine culture
- **must distinguish colonization vs. infection**
72
Candida spp. Bloodstream Infections
AKA candidemia
- more common in hospital
- Sx: high fever, chills, malaise, sepsis
- Dx: blood culture
- **never a contaminant!!!**
73
Candida spp. Treatments
C. albicans (fluconazole-susc), C. lusitaniae, C. parapsilosis, C. tropicalis, C. glabrata (flu-susc) = fluconazole
C. albicans (fluconazole-res), C. glabrata or C. krusei (fluconazole-res) = Echinocandin or Amphotericin B
| usually start more empiric & eventually move to fluconazole if possible
74
Fluconazole-susceptible Treatment normal dosing
800 mg (or 12 mg/kg) loading dose
400 mg (6 mg/kg) once daily
75
C. glabrata (fluconazole-susceptible dose dependent) dosing
800 mg (12 mg/kg) once daily
76
Fluconazole PK/PD
The AUC and dose have a linear relationship, so when giving a dose you can assume the AUC is the same
77
Cryptococcus neoformans
Opportunistic pathogen that affects the CNS and is typically acquired through inhalation of aerosolized cells from environment
| **Causes meningitis!**
78
Cryptococcus neoformans treatment
Induction: liposomal amphotericin B + flucytosine for 2 weeks
Consolidation: Fluconazole for 8 weeks
Maintenance: Fluconazole for 12 months
79
More common opportunistic mold pathogens are?
Aspergillus spp. and Mucormycetes (zygo one)
80
Aspergillus spp. concepts
- opportunistic so host needs to be immunocompromised
- primarily inhaled
- aspergillosis is the fungal infection caused by pathogenand mortality is high!
81
Examples of immunosuppression risk factors for invasive Aspergillosis
- prolonged neutropenia
- allogeneic hematopoietic stem cell transplant
- solid organ transplant
- inherited/acquired immunodeficiencies
- immunosuppressie therapies (TNFalpha inhibitors and corticosteroids)
- others
82
Invasive Pulmonary Aspergillosis
- Most common in neutropenia or those recieving cytotoxic chemotherapy
- Sx: pulmonary infiltrates, pleuritic chest pain, hemoptysis, fever
- can range from mild to destructive
- Halo sign(early) and Air-crescent(late) sign can be seen on the computed tomography
83
Invasive Aspergillosis treatment
VORICONAZOLE!
84
Dimorphics Pathogenicity
Primary pathogens: Coccidoides immitis, Histoplasma dermatitidis, Blastomyces capsulatum
**Endemic pathogens: cause disease via inhalation of spored from specific environmental/geographical locations**
85
Where is Coccidoides spp. found?
Highly endemic in southwestern US (Arizona, New Mexico, California, Nevada, Texas, Utah)
AKA "valley fever" or Coccidioidomycosis
86
Coccidoidomycosis risk factors/treatment
Risk factors: ethnicity, 3rd trimester, males, cellular immunodeficiency, extremes of age
Treatment: mild forms may not need treatment but if needed **fluconazole**
87
Where is Histoplasmosis found?
highly endemic in Ohio and Mississippi River valleys
88
Where is Blastomycosis found?
highly endemic in Ohio, Mississippi River valleys, and Great Lakes
89
Histoplasmosis and Blastomycosis treatments
mild forms may not need treatment
mild-moderate: itraconazole
severe/disseminated: liposomal amphotericin B or itraconazole
90
What is a virus?
neither prokaryotic or eukaryotic
- non-living, intracellular parasites
- no organelles or ribosomes
- cannot make energy/proteins independently of a host cell
- genomes may consist of RNA or DNA (NEVER BOTH)
- morphology: naked capsid or envelope
91
How are viruses classified?
structure, biochemical characteristics, disease, means of transmission, host range, tissue or organ
92
Steps in Viral Infection of Host Cell
| IN ORDER
1. Recognition of target cell
2. attachment
3. penetration
4. uncoating/release of genome
5. transcription
6. protein synthesis
7. replication of genome
8. assembly of virus
9. lysis of naked capsid viruses or budding of enveloped viruses --> release
93
What are the Nucleo**s**ide Analogs?
- Acyclovir
- Valacyclovir
- Ganciclovir
- Valganciclovir
94
What is the Nucleo**t**ide Analog
Cidofovir
95
What is the Pyrophosphate Analog?
Foscarnet
96
What is the CMV DNA Terminase Complex Inhibitor
Letermovir
97
What is the Neuraminidase Inhibitor?
Oseltamivir
98
HSV-1 and HSV-2
Herpes Simplex Type 1 and 2
Spreads through close contact (STD)
Subfamilies: HHV-1 and HHV-2
Targets mucoepithelial cells
99
VZV
Varicella-zoster virus
subfamily: HHV-3
spreads through respiratory and close contact
Targets mucoepithelial cells and T-cells
100
EBV
Epstein-Barr virus
subfamily: HHV-4
spreads through saliva (its mono)
targets B-cells and epithelial cells
101
Cytomegalovirus
subfamily: HHV-5
spreads through close contact (STD), transfusions, tissue transplants, and congenital
targets monocytes, granulocytes, lymphocytes, and epithelial cells
102
HSV triggers
- Ultraviolet B radiation (skiing, tanning)
- Fever
- Emotional stress
- Physical stress
- Menstruation
- Foods (spicy, allergic, acidic)
- Immunosuppression
| basically body stresses
103
Orolabial and Mucocutaneous HSV
Clear vesicles that rapidly ulcerate
Sx: soreness, burning sensation, tingling, blisters, rashes
Dx: PCR
Tx: topical meds, oral acyclovir or valacyclovir
**recurrences are normal**
104
Genital HSV
Grouped 2-4 mm vesicles with underlying erythema that progress to ulcers
Sx: super painful ulcers/lesions, fevers, headache, myalgias
Dx: PCR
Treatment: oral acyclovir or valacyclovir
105
Varicella (Chickenpox)
Caused by Varicella Zoster
-more common in children
Tx immunocompetent: supportive care
Tx immunosuppressed: acyclovir, valacyclovir
106
Herpes Zoster (Shingles)
Results from reactivation of a patients latent virus acquired earlier in patients life
- severe pain precedes appearance of chicken pox-like lesions and can be fatal in immunocompromised
- Tx: Acyclovir or Valacyclovir and potentially analgesic for neuralgia
- Immunity wanes in elderly population so more common for them to get it
- lesions are viable virus so be careful around non-immune
107
Varivax Vaccine treats
Chickenpox
live attenuated vaccines
108
ProQuad Vaccine treats
Chickenpox
Live attenuated vaccine
109
Shingrix treats
Shingles
Inactivated Vaccine
110
Most novel coronavirus is?
SARS-CoV-2: virus name
COVID-19: disease name
111
What are the 4 structural proteins of SARS-CoV-2?
1. **Spike protein**: Vaccines work with this one. It mediates binding and fusion with host cell membrane. Forms the crown.
2. Membrane protein: viral assembly
3. Envelope protein: transmembrane protein
4. Nucleocapsid protein: forms nucleocapsid
112
COVID-19 Therapies
- monoclonal antibodies
- dexamethasone
- remdesivir
- paxlovid
- molnupiravir
113
# COVID-19
Remdesivir indications
antiviral: nucleotide analog prodrug
IV only
use in hospitalized patients requiring oxygen
114
# COVID-19
Dexamethasone indications
corticosteroid
use in hospitalized patients requiring oxygen, mechanical ventilator support, or extracorporeal membrane oxygenation
115
COVID-19 Tx WE DON'T USE
hydroxychloroquine and ivermectin
116
# COVID-19
Pfizer-BioNTech Vaccine
mRNA
MOA: encodes the prefusion spike glycoprotein of SARS-CoV-2
117
# COVID-19
Moderna Vaccine
mRNA
MOA: encodes the prefusion spike glycoprotein of SARS-CoV-2
118
# COVID-19
Janssen (J&J) Vaccine
Replication-incompetent adenovirus vector
MOA: vector expresses the SARS-CoV-2 spike glycoprotein
119
What is Antigenic drift?
small mutations in the genes that lead to changes in surface proteins of the virus
120
What is Antigenic shift?
Abrupt, major change due to reassortment that lead to changes in surface proteins of the virus
121
Influenza
"the flu"
Sx: malaise, headache, fever, chills, loss of appetite, weakness, fatigue
Tx: supportive care, Oseltamivir, Influenza cap-dependent endonuclease inhibitor
122
Influenza vaccine is recommended to?
Everyone at least 6 y/o once a year
123
What are the HIV risk factors?
- unprotected sex
- sharing contaminated injecting equipment
- accidental needle stick
124
How is HIV transmitted?
sexual contact, blood, breast milk, semen, vaginal secretions, and perinatal
125
HIV MOA
preferentially infects and kills helper T-lymphocytes (CD4+ cells) which results in a loss of cellular immunity and vulnerability to opportunistic infections
126
What is the HIV life cycle?
1. Binding
2. Fusion
3. Reverse transcription
4. Integration
5. Replication
6. Assembly
7. Budding
127
# HIV drug
What is an NRTI?
Nucleoside Reverse Transcriptase Inhibitor
- works on reverse transcription step
128
# HIV drug
What is an NNRTI?
Non-nucleoside Reverse Transcriptase Inhibitors
129
# HIV drug
What is an INSTI
Integrase inhibitors
130
# HIV drug
What is a PI?
Protease inhibitor
131
How to diagnose HIV?
HIV serology: detection of Ab against virus
HIV viral load: amount of HIV in blood
CD4 cell count: indicator of HIV progression
132
HIV treatment
2 NRTI's + INSTI or NNRTI or PI with PK enhancer
133
What is zoonoses?
diseases/infections naturally transmitted to humans from vertebrate animals either directly or indirectly through an insect vector
134
What does "vector-borne" mean?
When a blood-feeding arthropod is involved
ex: mosquito/tick
135
Dog Bite/Scratches organisms
Pasteurella canis or Pasteurella multocida
OR rarely Rabies lyssavirus
136
Cat bite organism
Pasteurella multocida
137
Cat scratch organism
Bartonella henselae
138
Small rodent bites organism
Streptobacillus moniliformis
139
Pasteurella canis and multocida Treatment
Amoxicillin/Clavulanate
140
Rabies treatment
Pre-exposure prophylaxis: rabies vaccine
Post-exposure prophylaxis: rabies vaccine + rabies immunoglobulin
141
Cat scratch disease treatment
Azithromycin +/- rifampin
or
Doxycycline +/- rifampin
| reminder this is Bartonella henselae
142
Rabbit/muskrat/praire dog/ticks/deer flies organism
Francisella tularensis
143
Francisella tularensis treatment
Gentamicin or doxycycline
144
# TIcks
Lyme Disease is caused by
Borrelia burgdorferi
145
# ticks
Ehrlichiosis is caused by
Ehrlichia spp.
146
# tick
Rocky Mountain Spotted Fever is caused by
Rickettsia rickettsii
147
How do you treat a tick-borne illness?
Doxycycline!
148
How do you get Toxoplasmosis?
CD4 counts <50-100
Cat feces
Eating undercooked meat
Gardening
149
Toxoplasmosis Prophylaxis and Treatment
Prophylaxis: TMP/SMX if CD4<100 and toxoplasma IgG is positive
Tx: Pyrimethamine + sulfadiazine + leucovorin
150
What is a Trophozoite?
Motile, active feeding stage of protozoa
151
# Parasite
What is a Cyst?
Nonmotile, nonmetabolizing, nonreproducing form. This form is dormant and resting. This is how it can survive outside of the host.
152
Trichomonas vaginalis
one of the most common STD's that infects squamous epithelium in the urogenital tract
- exists only in trophozoite form
- transmission is via sexual contact
153
Trichomoniasis treatment
Metronidazole whether asymptomatic or symptomatic
154
Malaria
Caused by Plasmodium and spreads to humans via Anopheles mosquitoes
155
4 different Malaria species
P. falciparum, P. vivax, P. ovale, P. malariae
156
Mild Malaria Treatment
Artemisinin-based combination therapy
157
Severe Malaria treatment
Start with Parentaral artesunate for 24 hours then complete treatment with artemisinin-based combination therapy
158
Enterobiasis
Pinworms
diagnosed by finding eggs on perianal tape swabs. eggs are rarely fond in stool.
159
Enterobiasis treatment
Albendazole
OTC: pyrantel pamoate
