Infectious Diseases Flashcards
What does linezolid (Zyvox) cover?
Linezolid is bacteriostatic against enterococci and staphylococci and bactericidal against most strains of streptococci [Retrieved from LexiComp]
Generally, what is the mechanism of action of linezolid (Zyvox)?
It inhibits bacterial protein synthesis. [Retrieved from LexiComp]
What species of organisms is Zosyn effective against?
Alcaligenes species
Bacteroides species
Enterobacter species
Prevotella species
Pseudomonas aeruginosa
Serratia species
[Retrieved from Lexicomp: http://online.lexi.com/lco/action/doc/retrieve /docid/patch_f/7499#dcolist-ext]
What are the basic characteristics of pseudomonas aeruginosa?
Pseudomonas aeruginosa is motile and rod shaped, measuring about 0.6 × 2 μm. It is gram-negative and occurs as single bacteria, in pairs, and occasionally in short chains. Pseudomonas aeruginosa is an obligate aerobe. [Retrieved from Access Medicine: Jawetz, Melnick, & Adelberg’s Medical Microbiology, 27e, http://accessmedicine.mhmedical.com.libproxy .usouthal.edu/content.aspx?sectionid=94107120&bookid=1551&jumpsectionID =94107125&Resultclick=2]
What are the basic characteristics of the Bacteroides species?
The Bacteroides species are very important anaerobes that cause human infection. They are a large group of bile-resistant, non–spore-forming, slender gram-negative rods that may appear as coccobacilli. [Retrieved from Access Medicine: Jawetz, Melnick, & Adelberg’s Medical Microbiology, 27e, http://accessmedicine.mhmedical.com. libproxy.usouthal.edu/content.aspx?sectionid=94107632&bookid=1551&jumpsectionID =94107648&Resultclick=2#1114734543]
What is Hutchinson sign (related to herpes zoster/ophthalmology)?
Relates to involvement of the tip of the nose from facial herpes zoster. It implies involvement of the external nasal branch of the nasociliary nerve (branch of the ophthalmic division of the trigeminal nerve) and thus raises the specter of involvement of the eye.
[Retrieved from https://radiopaedia.org/articles/hutchinson-sign-disambiguation]
What are the drugs of choice to cover Enterococcus faecalis?
penicillin G
ampicillin
amoxicillin
vancomycin
teicoplanin
What are the drugs of choice to cover MSSA?
cefazolin
nafcillin
oxacillin
cloxacillin
flucloxacillin
dicloxacillin
fusidic acid
linezolid (+ only)
A sexual assault victim should be offered all of the following as prophylaxis:
azithromycin and ceftriaxone
Plan B
metronidazole
post-exposure prophylaxis for HIV
[from Board Vitals; American Family Physician, 2010]
The risk of transmission of HIV from a mother to her baby is believed to be related to the _____ ____.
The risk of transmission is as high as __% in untreated mothers, to as low as > _% in mothers who receive perinatal antiviral medication.
viral load
33%
7%
What is currently the drug of choice for treating Listeria monocytogenes infections?
Ampicillin
Which drugs are members of the aminopenicillins?
ampicillin, amoxicillin, (and others that are not available in the U.S.)
Klebsiella is always resistant to ________________.
aminopenicillins
[Dr. Echaiz]
Which class of antibiotics tend to fail when treating pneumonia?
aminoglycosides
What is the drug of choice for coverage of Morganella species?
cefepime
Why is cobicistat included in many HIV regimens?
Cobicistat is an inhibitor of the cytochrome P450 3A (CYP3A). Cobicistat increases the systemic exposure of CYP3A substrates atazanavir and darunavir. Used only in the treatment of HIV-1 infection.
Giemsa stain is used to…
….identify intracellular organisms such as chlamydiae and Plasmodium (malaria) and other parasites.
[from Clinician’s Pocket Reference]
What is a Wright stain?
Wright’s stain is a histologic stain that facilitates the differentiation of blood cell types. It is classically a mixture of eosin (red) and methylene blue dyes. It is used primarily to stain peripheral blood smears, urine samples, and bone marrow aspirates which are examined under a light microscope.
Name the 3 commonly used aminoglycosides.
Are these drugs effective against Pseudomonas aeruginosa?
gentamicin, tobramycin, amikacin
Yes, usually; (+) rating in Sanford
Which carbapenem is the only one that doesn’t cover Pseudomonas?
ertapenem
Triumeq is a combination of 3 drugs (____________ + ________ + __________), given as a _____ daily regimen.
dolutegravir + abacavir + lamivudine
once
The majority of clinically reported cases of TSS have been due to what organism?
methicillin-susceptible Staphylococcus aureus
What 4 antibiotics are considered drugs of choice for coverage of Bartonella species…
gentamicin
azithromycin
clarithromycin
doxycycline
(Sanford Guide)
What are the drugs of choice for coverage of Pasteurella species?
What can you use in a patient with PCN allergy?
penicillins – including penicillin G, penicillin VK, ampicillin, ampicillin-sulbactam
levofloxacin
aztreonam
Stenotrophomonas maltophilia is intrinsically resistant to virtually all __________ (penicillins, cephalosporins, aztreonam, and carbapenems) due to the presence of zinc-dependent metallo-beta lactamase.
beta-lactams
From Sanford Guide
What are the former names of Stenotrophomonas maltophilia?
- Xanthomonas maltophilia*
- Pseudomonas maltophilia*
What is the morphology and Gram classification of Stenotrophomonas maltophilia?
Gram negative bacilli
Nosocomial Klebsiella pneumoniae pulmonary infections usually present as ______________ or __________. In a series of 198 cases of acute K. pneumoniae pneumonia, the majority of which were nosocomial, the most common CT findings were ground glass opacities (100 percent), alveolar consolidation (91 percent), intralobar reticular opacities (86 percent), and pleural effusions (53 percent) [34].
bronchopneumonia or bronchitis
What are the risk factors for MRSA infection?
Septic shock
Respiratory failure requiring MV
Gram + cocci in clusters on Gram stain
Known colonization with MRSA
Recent influenza-like illness
Antimicrobial therapy (particularly with a fluoroquinolone) in the prior 3 months
Necrotizing or cavitary pneumonia
Present of empyema
Risk factors for MRSA colonization:
ESRD
Men who have sex with men
Living in crowded conditions
Incarceration
Injection drug use
Contact sports participation
[From algorithm 4 in UpToDate article: “Overview of community-acquired pneumonia in adults”]
What are the risk factors for Pseudomonas?
Structural lung abnormalities (e.g. bronchiectasis)
Frequent COPD exacerbations requiring frequent glucocorticoid or antibiotic use
Gram-negative bacilli seen on sputum Gram stain
[From algorithm 4 in UpToDate article: “Overview of community-acquired pneumonia in adults”]
Chikungunya virus is an arthropod-borne alphavirus transmitted by __________ that causes ____ _______ ___________ and inflammatory arthritis as well as acute cutaneous eruptions and other systemic manifestations. The name chikungunya is derived from an African language and means “that which bends up” or “stooped walk” because of the incapacitating arthralgia caused by the disease.
mosquitoes
acute febrile polyarthralgia
[From UpToDate: “Chikungunya fever: Epidemiology, clinical manifestations, and diagnosis”]
Chikungunya is transmitted by the mosquito vectors _____ _______ and _____ __________. Infected travelers can import chikungunya into new areas; in areas with Ae. aegypti and/or Ae. albopictus mosquitoes, local transmission can follow. This has been described in many Asian and European countries as well as in the Americas and Australia.
Aedes aegypti and Aedes albopictus.
[From UpToDate: “Chikungunya fever: Epidemiology, clinical manifestations, and diagnosis”]
_____ and _____ viruses are transmitted by the same mosquito vectors as chikungunya virus. The viruses can cocirculate in a geographic region, and coinfections have been documented.
Dengue and Zika
[From UpToDate: “Chikungunya fever: Epidemiology, clinical manifestations, and diagnosis”]
“The more we expose microbes to antibiotics, the more opportunity they have to develop resistance. What you are left with, after a course of antibiotics, after all, are the most resistant microbes.”
Antibiotics are about as nuanced as a hand grenade. They wipe out good microbes as well as bad.
From Bill Bryson’s book, The Body, Chapter 3: Microbial You
There is an association between group D streptococci bacteremia, infective endocarditis, and _______ _________.
colonic neoplasia
The association of Streptococcus bovis bacteremia with colon tumors has been known since the late 1970s (3). Later, it was established that this association corresponded to biotype I (6). The association of S. bovis biotype II is less known. A few studies have related biliary tract infections and cirrhotic bacteremia (1, 5, 6, 8).
Extensive taxonomic changes have occurred in this group, and strains formerly known as human S. bovis isolates are now designated different species (2, 7). Thus, in human pathology today, there are two species of principal interest: Streptococcus gallolyticus, with the subspecies gallolyticus (formerly S. bovis I) and pasteurianus (formerly S. bovis II/2), and Streptococcus infantarius (formerly S. bovis II/1), with the subspecies coli and infantarius.
[From https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2292944/]
Streptococcus suis is an emerging zoonosis that causes meningitis in Asia and has been linked to exposure to ____ [15]. It is the most frequent cause of _________ __________ in adults in southern Vietnam and has caused outbreaks in China.
pigs
bacterial meningitis
[From UpToDate:
https://www.uptodate.com/contents/epidemiology-of-bacterial-meningitis-in-adults?search=strep%20suis&source=search_result&selectedTitle=1~4&usage_type=default&display_rank=1]
What organisms does the BioFire PCR meningitis/ encephalitis panel test for?
Bacteria:
- Escherichia coli K1*
- Haemophilus influenzae*
- Listeria monocytogenes*
- Neisseria meningitidis*
- Streptococcus agalactiae*
- Streptococcus pneumoniae*
Viruses:
- Cytomegalovirus (CMV)*
- Enterovirus (EV)*
- Herpes simplex virus 1 (HSV-1)*
- Herpes simplex virus 2 (HSV-2)*
- Human herpesvirus 6 (HHV-6)*
- Human parechovirus (HPeV)*
- Varicella zoster virus (VZV)*
Yeast:
Cryptococcus neoformans/gattii
[Retrieved from: https://www.biofiredx.com/products/the-filmarray-panels/filmarrayme/?gclid=EAIaIQobChMI1LCsgvPa6gIVNAnnCh1FNwR8EAAYASAAEgIBzfD_BwE]
What is a mycotic aneurysm?
An infection of a vessel wall which can be bacterial, fungal, or viral in origin; rare but severe complication of systemic infection and atherosclerosis
[From https://www.ncbi.nlm.nih.gov/books/NBK560736/]
What agents cover “all the anaerobes above the diaphragm”?
What about below?
clindamycin
cipro + flagyl, OR Zosyn
