Part 10 Flashcards
Amphotericine B mechanism of action
Bind ergosterol and disrupt fungal cell membrane by making it leak intracellular content especially K+
Azoles mech of action and ADR’s
Inhibit synthesis of ergosterol disrupting fungal cell wall, inhibit hepatic p450 enzyme increasing serum concentration of other drugs
echinocandin drugs (3) and their MOA and use
- anidulafungin
- caspofungin
- microfungin
disrupt cell wall, used in IV for invasive aspergillosis and candida
Herpesvirus group and ones there is treatment for
- Herpes simplex
- Varicella zoster
- cytomegalovirus
- epstein barr (no treatment)
Acyclovir
Agent of choice for herpes symplex and varicella zoster virus functions to inhibit viral DNA poly and incorporate into strand of viral DNA blocking further growth through cell conversion into acyclo-GMP
valacyclovir use and ADR (rare) and advantage of acyclovir
More popular prodrug form of acyclovir, approved for PO therapy in immunocompetent host, can cause thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) in very immunocompromised hosts, advantage is dosing is less often (2x per day opposed to 5 for acyclovir
Docosanol
OTC treatment for herpes labialis, inhibits fusion btwn plasma membrane and viral envelope increasing healing with first sign of coldsore
Ganciclovir and the prodrug version valgancyclovir that can be used oral has use against what?
cytomegaolvirus,particularly CMV retinitis
Direct acting antivriral drugs (DAAs)
Target specific steps in HCV replication without damage to healthy cells, often used in combination to decrease viral resistance
Triple therapy regimen
Original standard of care for HepC until DAA development, includes pegylated interferon alfa (notorious for causing damage to host cell), protease inhibitor, and ribavirin
Unlike Hep C, for Hep B and A we have a preventative …
..vaccine
Neuraminidase Inhibitors and most common example and how soon does this need to be started
Modestly suppress influenza A AND B, prophylacitc and treatment, oseltamivir, within 48 hours
amantadine and rimantidine MOA and function
dopaminergic agonist and noncompetitive NDMA antagonist, and antagonistm against release of viral injection of material by influenza A but most have resistance now, indicated for drug induced parkinsonism, tardive dyskinesthia, and parkinsons
HART therapy for HIV can be hard on this drug metabolizing system
cytochrome p450 causing toxicity with other drugs
Gram + cocci catalase test results
Positive is staph, negative is strep
Gram + cocci coagulase test results
Positive is staph aureus, negative is staph epidermidis
Localized staph aureus infections with systemic effects (2)
- Scalded skin syndrome
- toxic shock syndrome
MRSA outpatient options (3) and inpatient treatment
Outpatient - clindamycin, bactrim, doxycycline
inpatient - vancomycin
Staph saprophyticus is a common cause of this….
….UTIs in young women
S. pyogenes common localized infections
Impetigo (not as common as with s. aureus), necrotizing fasciitis, gangrene, erysipelas
S. pyogenes common invasive infections
Bacterial pharyngitis Scarlett fever throat abscesses Rheumatic fever Glomerulonephritis
S. agalactiae medical significance
Group B B hemolytic strep number one cause of death in newborns causing neonatial sepsis and postpartum infections, rarely adult infections
Strep pneumoniae common invasive infections
Pneumonia, ottitis media, sinusitis, meningitis
Strep viridans is known to be a causative agent of these 2 things…
Bacterial endocarditis and dental caries
Treatment option for VRE
Linezolid
Clostridium perfringens
Often source of wound and surgical infections that lead to gas gangrene
Corynebacterium diptheriae shape
Club or V shaped gives distinct appearance
Diptheria causes these symptoms (1 key one)
Upper respiratory tract illness characterized by fever, sore throat, and adherent membrane (key) on tonsils, pharynx, or nose
Endotoxin
Derived from the LPS protein layer on the outermost membrane of gram - organisms, released upon cell death to cause malaise but rarely fatal
Exotoxin
Substances released by living bacterium, can cause major damage to host and are fatal in large quantities
3 common features of hemolytic uremic syndrome
- Hemolysis
- Thrombocytopenia
- Renal failure
Campylobacter
Leading cause of bacterial gastroenteritis, birds and poultry often reservoirs
Campylobacter treatment
Often preventative, disease self limiting
Vibrio cholerae infection
Secretory diarrhea from cholera toxin 24hrsr after -3 days , can cause rice stools with fishy odor, can kill within 6-12 hours of dehydration
Salmonellosis presentation and treatment
sometimes bloody diarrhea, fever, crmaps
Avoid antibiotics (highly resistant, unless bacteremia), avoid anti-diarrheal agents, supportive therapy
Typhoid fever presentation and causative agent
Incubation for 8-14 days, sustained high fever, chills, some develop rose spots, salmonella typhi
Shigellosis
Humans are only reservoir, spread fecal oral, common cause of bacterial gastroenteritis, highly contageous, bloody watery diarrhea, abdominal pain, tenesmus, self limiting
Klebsiella pneumoniae
Most healthy people do not get sick, can be nosocomial in a compromised immune system, part of normal flora, sometimes I see this in elderly UTI
Klebsiella pneumonia classic presentation
Thick purulent mucoid sputum (currant jelly), lung abscesses, acute cholangitis
Triad for acute cholangitis
fever, upper right quadrant abdominal pain, jaundice
Pseudomonas aeruginosa
Opportunistic, nosocomial often infection can also infect hot tubs or ears in healthy, highly virulent, has fruity grape odor
Legionella pneumophilia
Derived from stagnate man made water sources such as air cooling system in legionnaire convention, not contageous person to person, most common atypical pneumonia
Haemophilus 4 species
Haemophilus influenza A or B, ducreyi, haemolyticus
Haemophilus ducreyi classic disease caused
Chancroid forming, genital ulcer disease
Fitz hugh - curtis syndrome
Rare disease found almost exclusively in women, inflammation of membrane lining stomach and the tissues surrounding the liver sequealae from untreated pelvic inflammatory disease by gonorrhea or chlamydia
Niesseria meningitidis drug of choice
Vancomycin
Ascariasis presentation
Often asymptomatic disease following roundworm infection, abdominal cramping, dry cough, or seeing worm in stool are possibilities, can lead to obstruction of bowels follwoing roundworm (ascaris lumbricoides) infection
Ascariasis/necator amerricanus/enterobius vermicularis treatment options (3)
Mebendazole, pyrantel pamoate, albendazole
Necator americanus causes what infection and course
Hookworm, 2nd most common helminth infection, buries thru skin in foot and then lays eggs in intestine causing bloody diarrhea, iron deficiency
Trichinella spiralis source and disease course, diagnosis
Most often found in undercooked pork, enter into skeletal muscle and form spiral growths, manifests as muscle aches, fever, and abdominal pain, serum CK for muscle breakdown but muscle biopsy definitive
Enterobius vermicularis disease course and diagnosis
Pinworm, unique in that it does NOT cause eosinophilia, often females lay eggs in anus at night causing itching in the evening, fecal oral or clothing food route… Scotchtape test - on anus in the morning, tape to a slide and bring in to look for eggs
Wuchereria bancrofti disease course
Cause of filarial fever, sequelae elephantitis, transmitted via mosquito, causes eosinophilia, resides in lymphatic system
Schistosomiasis diseae course
Blood fluke flat worm infection, egg passes from feces into fresh water, hatch and infect snails as host, leave and penetrate humans in water to mature and lay eggs
Schistosomiasis treatmnet
Praziquantal for most
Taenia solium
Tapeworms, can cause bloating, abdominal pain and diarrhea, intestinal obstruction, occasionally results in cysticercosis
Taenia solium treatmneet
Praziquantal or niclosamide, surgery, albendazole or mebendazole
Giardia lamblia disease course, treatment of choice
Flagellated protozoan, causes traveler’s diarrhea, waterborne, spread via person to person contact, diarrhea, bloating, distension, treatment of choice is metronidazole
Pediuclosis and treatment
Body lice, permethrin cream
Scabies course and treatment
Intense itching and rash with tunnel like course often in the folds of skin or interdigital webs, treatment is permethrin cream, crotamiton cream, and lindane cream
4 stages of T. pallidum infection
Primary syphilis - painless chancre typically on genitals 10-90 days after exposure that disappears after 6 weeks
Secondary - rash and eruptions maculopapular rash on palms and feet, wart like lesions condyloma lata
Latent - seropositive but symptom negative
Tertiary - vascular and neurologic manifestations gummatous or neuro
DOC for primary and 2ndary syphilis vs tertiary
PCN G vs aqueous crystiline PCN
Borrelia burgdorferi
Causative agent of lyme disease, carried by tick bite, causes erythema chronicum migrans in early stage (bullseye rash)
name 2 common spirochete infections
syphilis and lyme disease
3 stages of lyme disease
Early stage - localized bullseye rash (erythema chronoicum migrans)
Disseminated stage - skin lesions, CNS facial nerve deficits
Late stage - persistent infection, rarely progresses to worse
Lyme disease treatmnet options (2)
Doxycycline, amoxicillin, no preventative vaccine
3 phases of TB
Primary - active symptoms, abnormal chest x ray and positive sputum smear, middle loung
Latent - no symptoms not contageous, positive PPD read
Reactivated - macrophages housing mycobacterium as reservoir allow for reactivation, immunocompetent low chance of reactivation, seen in upper lobes
Primary TB is seen in the ___ lobe but reactivated in the ____
Middle lung, upper lung
Miliary Tb
Widespread Tb that looks like a snowstorm on the x ray
Langhans giant cells
recruited by macrophages in the lungs to engulf Tb and form a necrotic mass
Ghon lesion
Necrotic mass of Tb, macrophages, and langhans giant cells on the lung tissue
Ghon complex
Presence of a ghon lesion with lymphoadenopathy on the same side
Ranke complex
Presence of a ghon lesion that has been calcified with lymphoadenopathy on same side
TB transmission
Tiny droplets from one with active TB to another individual
TB and HIV
TB is most commonc cause of death in patients with AIDS, AIDS patients won’t get positive ppd even if have active TB infection
3 types of TB
Pulmonary - dry cough, fever
Extrapulmonary - other organs, pott’s disease
Miliary - disseminated
Pott’s disease
Skeletal muscle disorder for spinal TB where a child comes in limping with a curve like scholiosis
different methods of TB testing
PPD test can screen for exposure (induration diameter NOT redness), chest x ray, 3 sputum samples , quanti-feron tests, culturing still gold standard, AFB smear - positive for all mycobacterium
Booster phenomenon of PPD
In 2 step ppd if 1st test is negative but 2nd is positive
Quanti-feron test
Blood test specific and sensitive for TB done in a single visit with results available in 24 hours avoiding booster effect and prior BCG vaccination, but expensive, and low data
Mycobacterium leprae
Hansen’s disease, spread exact same way as Tb via droplets, can treat contagiousness but not deformities, comes in 2 major forms tuberculoid impacting NS and lepromatous of the skin
Mycobacterium avium
AIDS defining illness, nontuberculus mycobacteria that naturaly occur everywhere, opportunistic
all mycobacterial infections require…
…multidrug therapy
Dermatophytes definition
Include tinea (ringworms) capitus - head, barbe - beard, corperus - body, pedis - feet
Dermatophytes diagnosis
KOH skin scrapings, wood’s light, culture
Retroviruses
Class of RNA viruses that can produce double stranded DNA copies of their genome and then integrate into the chromosome of the host cell using reverse transcriptase, key example being HIV
Influenza is what type of virus?
RNA virus
Coronavirus is what type of virus?
RNA virus
Rhinovirus is the most common cause of what…
Most common cause of common cold
Rhinovirus is what type of virus?
RNA virus
Adenovirus is what type of virus?
DNA virus
Adenovirus symptoms
URI (it is considered in that class), conjunctivitis, GI symptoms
Parainfluenza is also known as…
Croup
What type of virus is parainfluenza
RNA
Respiratory syncytial virus (RSV) is what type of virus?
RNA virus
Buzzword of RSV
Bronchiolitis
What type of virus is mumps?
RNA virus
Major feature of mumps
Bilateral parotitis and orchitis
Rotavirus is what type of virus
RNA virus
Rotavirus is the leading cause of what….
…severe gastroenteritis in children
Norovirus is what type of virus
RNA virus
Norovirus is the most common cause of…
non bacterial gastroenteritis
Coxsackievirus A frequently causes…
Hand-foot-and-mouth disease, fever and vesicles on mouth and hands and feet
Poliovirus symptoms
Nonspecific, fever, malaise, neck and back pain, motor weakness and long term paralysis
Rubeola virus causes…
Measles, most contagious disease known to humans
Koplik spot
Small bluish white raised spots on oral mucosa indicative of measles rubeola virus presence
What type of virus is rubeola?
RNA virus
Herpes simplex virus is what kind of virus?
DNA
Varicella zoster virus is waht type of virus?
DNA
Varicella zoster virus classic rasih description
vesicular dew drops on rose petal rash
Parvovirus B19 causes what disease and symptoms?
Fifth disease,
rash with erythematous color on cheeks looking slapped
Parvovirus B19 is what type of virus?
DNA
Epstein barr virus is what type of virus
DNA
Cytomegalovirus is the leading cause of ____ in HIV patients
Blindness via retinitis
Cytomegalovirus is what type of virus
DNA virus
Human papilloma virus (HPV) is what type of virus?
DNA virus
Flaviviruses
Zika, dengue, yellow fever and west nile
Zika virus often causes what in pregnant women’s children?
Microcephaly
Chikungunya often causes…
…Breakbone disease, intense joint pains
As with all flaviviruses, until dengue has been ruled out, we should avoid ___, why?
NSAIDS, dengue can increase bleeding risk
