Clinician's view of pathogenic microbes Flashcards
what are the 4 types of pneumonia-meningitis bacteria?
- Strep pneumoniae (MCC meningitis > 18 y/o)
- Haemophilus influenzae
- Neisseria meningitidis (MCC of meningitis 1 month - 18 y/o)
- moraxella catarrhalis (bloodstream invasion rare)
what do all the bacteria that cause meningitis have in common?
they all have capsules (that make them resistant to phagocytosis)
what are the vaccines made of that protect against microbes causing bacterial meningitis?
made of capsular polysaccharide
what kind of pts are at an increased risk of overwhelming sepsis + meningitis?
asplenic pts
what kind of bacteria cause dental caries?
strep mutans (type of viridans strep)
what are the HACEK microbes?
H-hemophilus A-actinobacillus C-Cardiobacterium E-Eikenella K-kingella tiny, fastidious, G neg. bacilli that can cause endocarditis
the infections caused by the not so bad staph and strep are generally not fulminant except in what pts?
granulocytopenic pts
Staph Aureus likes to inhabit what part of skin?
ant. nares
staph aureus can cause pneumonia in what kind of pts?
pts on ventilators (ventilator assoc. pneumonia)
name the microbe: infects prosthetic devices & iv catheters by producing adherent biofilms, and csf shunts?
staph epidermis
name the microbe: G+, cocci, Cat+, clusters, Coag neg. novobiocin sensitive
Staph epidermis
what is erysipelas and what pathogen causes it?
a fiery-red, rapidly enlarging, painful patch of skin and subq tissue; caused by Strep pyogenes
where do group B strep (strep. agalactiae) like to live?
colon and vagina
which pathogen is the leading cause of sepsis and meningitis in the neonate?
Group B strep
how does the neonate acquire a group b strep infection?
acquired from birth through vaginal canal (can use antibiotics for prophylaxis if mom is carrier)
name the pathogen: cousins to strep, G+ cocci, seen in pairs, normal GU & GI flora of low virulence, usually part of mixed infections, can cause UTIs and endocarditis
enterococci (group D strep)
when you find enterococci in the blood stream what should be thinking about as far as sources?
IV catheters, GI lesions (esp. tumors)
which pathogens are considered the world’s most antibiotic-resistant bacteria?
enterococci (group D strep)
how do you treat enterococci infections?
takes 2: penicillin + aminoglycoside
which pathogen is considered to be the most famous nonfermenter and is a gram neg. rod, oxidase +
pseudomonas aeruginosa
which pathogen flourishes in pts treated with broad-spectrum antibiotics, and is an important cause of nosocomial infections esp. UTIs, & IV catheter
candida
name the pathogen: a diptheroid (club-shaped gram-positive rod) that is an important cause of meningitis in neonates
listeria monocytogenes
name the pathogen: cause of chronic meningitis in both normal & IC pts, distinctive capsule seen on india ink preps of CSF
cryptococcus (Y)
name the pathogen: causes a necrotizing sinusitis that invades the brain in pts with DKA & in severely IC or granulocytopenic pts
zygomycetes (M) dz = rhinocerebral mucormycosis
which systemic fungal pathogen is acquired in teh southwest and of the 3 (coccidioides, blasto, histo) is the most apt to invade the CNS to cause meningitis?
coccidioides (Y)
name the pathogen: yeast that causes lymphangitis in the form of subq nodular inflamm. lesions marching up a lymphatic vessel after a puncture wound, esp. in gardners who use sphagnum moss
sporothrix
which pathogens are considered the smallest free-living organisms?
mycoplasmas
which pathogens has no cell wall and is the leading cause of atypical pneumonia?
mycoplasma pneumoniae
what kinds of infections are caused by M. hominis & ureaplasma?
genital tract infections, esp. urethritis in men and postpartum endometritis in women
which pathogen is the MC sexually transmitted GU infection?
Chlamydiae trachomatis
which serotypes of chlamydia trachomatis cause lymphogranuloma venereum?
L1, L2, L3
which pathogen causes psittacosis?
Chlamydiae psittaci, severe febrile pneumonia acquired from birds
which bacterial pathogens can’t make their own ATP?
Chlamydiae (obligate intracellular organisms)
where do the rickettsiae replicate?
replicate intracellularly esp. in endothelial cells
which pathogen, that can be cultured on artificial media can ause cat-scratch disease, trench fever, bartonellosis, peliosis hepatis bacillary angiomatosis ( an AIDs disease)
bartonellae
which two pathogens are known to be causes of fever of unknown origin in normal and IC hosts?
bartonellosis ehrilichiosis
name the pathogen: monocytes with morula (berry-like ) inclusion in cytoplasm
ehrlichiosis
which helminth can live its entire cycle in humans?
strongyloides (threadworm)
what is the term for when strongyloides take e. coli with them to various organs?
piggyback sepsis
what is the most common parasitic disease worldwide?
ascariasis
what types of viruses tend to cause acute infections?
RNA viruses
name the pathogen: causes cold sores, rarely severe necrotizing encephalitis
HSV1
what is the most common manifestation of HSV1 in IC pt?
esophagitis
name the pathogen: causes genital herpes, severe infections in neonate
HSV2
how could you help prevent neonate from infection of HSV when mom has active genital herpes at the time of birth?
C-section
which virus causes roseola (aka exanthem subitum, baby measles)?
HHV-6
the roseola virus is cytopathic for what kind of cells?
CD4 cellS
subclinical reactivation of what roseola is common in what circumstances?
immunodeficiency and CMV infection
which virus causes Kaposi’s sarcoma?
HHV8
