Microbio 4 2

Start Studying!

Terms

undefined, object

copy deck

what is the MOA for bacitracin?: disrupts cell membranes
all the bacteria discussed in the food & water borne infections lecture (basically) share what same characteristic?: they're all gram(-)
what is the main EHEC virulence factor to remember?: SLT -- shiga-like-toxin

stops protein synth; destroys intestinal epithelium --> blood slough
how big of an inoculum is required for salmonella infection?: large dose
what are the two virulence factors for salmonella?: (1) enterotoxin -- cholera-like

(2) cytotoxin -- inhib protein synth
when are the symptoms of Salmonella enterica Typhi seen?: 1-3 weeks after ingestion
what is a major point to remember about salmonella (typhoid) invasion system: type III --> ruffling --> "phagocytosis"
how does Shigella enter M cells of intestine?: "invasion plasmid antigens" (IpaBCD) to enter M cells, and pass through into lamina propria
what virulence factor does shigella need to spread from cell to cell?: IcsA -- Intracellular spread ATPase (actin polymerization)
how many organisms needed to ingest to become infected with V. cholera?: lots
what are the three genera of spirochetes: treponema, borrelia, and leptospira
what is the causative agent of syphilis?: T. pallidum
desc the three stages of syphilis: (1) primary stage

sex transmission; chacres develop w/in 2-4 wks exposure; highly infectious

(2) secondary stage

3-6 wks after primary; flu-like illness, fever, sore throat, headache, hair loss, etc; very infectious soars

(3) tertiary stage

may be LONG after secondary; organ and tissue distruction via gumma (granulamatous lesions of soft tissue and viscera)
what is the drug of choice for treatment of syphilis?: penicillin
what are bejel, yaws and pinta and where do they occur?: nonsexual versions of syphilis

bejel -- eastern meditteranean and w africa

yaws -- equatorial

pinta -- indians of mexico
yaws full name: T. pallidum subspecies pertenue
pinta full name: T. pallidum subspecies carateum
bejel full name: T. pallidum subspecies endemicum
which treponemal species is most strongly associated with periodontal disease?: T. denticola
vincents angina: an oral infection of the mouth and gums; a polymicrobial infection involving fusobacterium necrophorum and treponema vincentii
gram stain and morphology of neisseria species: small gram(-) arranged in pairs (diplococci) with flattened adjacent sides (resembling kidney beans)
motility and metabolism of neisseria: non-motile (no flagella)

aerobic metabolism -- oxidase positive
N. meningitidis produces acid from which of the following: glucose, maltose, lactose, sucrose: glucose, maltose
what determines N. meningitidis serogroup?: the capsular polysaccharide
what determines N. meningitidis immunotype?: Lipooligosaccharide (LOS)
reduces severity of neurological sequelae of N. meningiditis: dexamthazone (use is controversial)
chemoprophylaxis for N. meningiditis: oral rifampin (or ciprofloxacin)
N. gonorrhoeae - produces acid from what? - oxidase?: oxidase positive and produces acid from glucose only
phase variation of N. gonorrhoeae: shift b/t P+ (piliated) P++ (highly piliated) and P- (non-piliated), mediated by chromosomal recombination
does N. gonorrhoeae exhibit capsular polysaccharides?: NO
how do you distinguish the following organisms from Neisseria gonorrhea? Acinetobacter Kingella Moraxella: Acinetobacter: oxidase negative
Kingella: oxidase positive coccoid bacilli, catalase negative
Moraxella: does not produce acid upon fermentation of glucose
therapy for uncomplicated urethral, cervical, or rectal N. gonorrhoeae infection: ceftriaxone
what should you add to the treatment regimen for N. gonorrhoeae is patient if coinfected with Chlamydia trachomatis: ceftriaxone (for N. gonorrheoeae)

doxycycline or azithromycin added
desc the peptidoglycan layer of Chlamydia: they don't have one
transmission in C. psittaci: humans infected only by inhaling organisms in dried bird feces
what is the most common STD in the US: chlamydia trachomatis
what are the two forms of borrelial relapsing fever?: tick borne (TBRF)

louse borne (LBRF)
what is the treatment for borrelial relapsing fever?: doxycycline, erythromycin
reservoir for lyme disease: deer, mice, small mammals, lizards

ticks are not reservoirs, but they are the primary TRANSMITTERS
treatment for lyme disease: doxycycline in early phases

IV rocephin in later stages
where is the flagella of spirochetes located?: periplasmic endoflagella, in between the outer and inner membranes
what type of microscopy do you use to visualize spirochetes?: darkfield microscopy (cause they're thin)
what are the two ways to confirm a diagnosis of syphilis, and what stages are they useful for: non-treponemal (VDRL & RPR)
- secondary and latency
- best in neurosyphilis

treponemal (FTA & MHA)
- best for early and late stage
treatment of choice for syphilis - how 'bout for neurosyphilis - how 'bout for HIV patients?: penicillin

neurosyphilis --> chloramphenicol

HIV patients --> ceftriaxone
what is the only pathogenic gram(-) cocci?: neisseria
does N. gonorrheae have a polysaccharide capsule?: NO
N. meningitidis PorB: - translates into host cell membranes
- effects on apoptosis
- induces phagocytosis
which serogroup is the most common cause of epidemic meningitis?: Serogroup A
Waterhouse-Friderichsen Syndrome: systemic meningitidis infection
- adrenal glands destroyed
gonococcal opacity protein: (Opa) -- PII

- allows cell-to-cell adherence
- influences cell tropism
of the gonococcal porins, which one leads to disseminated and which one to localized infection?: PorB1A disseminated
PorB1B localized
what bug is the cause of opthalmia neonatorum?: N. gonorrhoaea
therapy for N. gonorrhoeae infection: ceftriaxone, ciprofloxacin
therapy for N. gonorrh coinfection with Chlamydia trachomatis?: ceftriaxone + doxycycline
desc the vaccine for N. gonorrhoeae: no vaccine available
differentiate b/t presumptive and definitive diagnosis of gonorrhoeae: The "presumptive diagnosis" only requires that 2 out of the 3 conditions be met. Thus, the presence of GNIDS in a urethral exudate and detection by an antigen detection test, in the absence of growth and isolation of N. gonorrhoeae, would be sufficient for a presumptive diagnosis. However, a "definitive diagnosis" requires both cultivation of N. gonorrhoeae from sites of exposure AND confirmation with biochemical tests.
what is special about the borrelia genome?: segmented genome -- linear and circular DNA
clinical picture of relapsing fever: - borrelia
- massive numbers of spirochetes in blood
what accounts for the "relapse" of relapsing fever: Vmp antigenic variation protein
- about 40 of em
- 1 expressed at a time
- immune syst kills bacteria --> some recombination --> relapse --> continue cycle
treatment for relapsing fever: doxycycline, erythromycin
is there any transovarial transmission for lyme disease?: NO
what is the specific ELISA test for lyme disease?: C6 peptide ELISA test
yersina pestis - general info: gram(-) rods, facultative anaerobes, enterobacteriaceae family, nonmotile
symptoms of bubonic plague: swollen ulcerated lymph node (bubo); surface hemorrhages may cause the skin to turn black (black death)
treatment for bubonic plague: antibiotics (streptomycin, chloramphenicol, or tetracycline)
pathogenesis of bubonic plague: flea bite --> blood stream --> PMNs (killed), nonactive macs (live) --> carried to mesenteric lymph node --> buboes --> leave mac and go through bloodstream --> subcutaneous hemorrhages
what are the three virulence factors for yersina?: (1) adhesins

(2) plasmid-encoded YOP proteins -- injected into host cells by Type III secretion

(3) Plasminogen Activator Protease -- prevents clots
Francisella Tularensis "tularemia" general info: small gram(-) rods, facultative anaerobe, require a rich medium + cystine
what is the most virulent organism to infect humans?: Francisella Tularensis
what are the three major manifestations of tularemia?: (1) ulceroglandular tularemia

(2) pneumonic tularemia

(3) typhoidal tularemia
which disease is associated closely with rabbit hunters?: tularemia (Francisella Tularensis)
why is francisella tularensis such a good potential biowarfare agent?: (1) EXTREME infectivitiy

(2) ease of dissemination

(3) substantial capacity to cause illness and death
Human Brucellosis -- aka: Malta fever
Human Brucellosis: reticuloendothelial system (RES) primarily infected producing prolonged febrile systemic illness
infected cat or dog bite -- what organism?: Pasteurella Multocida
Pasteurella Multocida - general desc: small gram(-) coccobacilli
what are the two smallest known free living bacteria?: mycoplasma and ureaplasma
what class do mycoplasma and ureaplasma belong to?: mollicutes
desc the unique structure of mollicutes: lack a cell wall or peptidoglycan and contain sterols in their membrane
what is referred to as walking pneumonia?: pneumonia caused by mycoplasma pneumoniae (for people aged 5-35)
what are the preferred antibiotics for mycoplasmal pneumonia and why?: erythromycin and doxycycline

Remember, cell wall inhibitors are ineffective
mycoplasma hominis: causes urethritis in males; sexual transmission
ureaplasma urealyticum: same diseases as Mycoplasma but may also be involved in urinary tract stones
what is the etiological agent of granuloma inguinale?: calymmatobacterium granulomatis
Rickettsia - general info: enter cells by induced phagocytosis

produce membrane disrupting phospholipase A (escape from phagolysosome fusion)

can obtain ATP from host mitochondria
what is the hallmark of rickettsial infections?: necrotizing vasculitis and INC vascular permeability
what are the three major groups of rickettsia?: (1) rocky mountain spotted fever (RMSF) group

(2) typhus group

(3) scrub typus group
rocky mountain spotted fever - transmitted by?: dermacentor ticks (dog or wood ticks) --> also maintained in ticks by transovarial transmission
clinical picture of rocky mountain spotted fever: fever, chills, headache and myalgia, 3-5 days later rash spreads
rickettsia prowazekii - causative agent of?: epidemic or louse borne typhus
Brill-Zinsser disease: epidemic typhus reactivating decades after initial infection
coxiella burnetti - associated with what condition?: Q fever
Q fever: primarily an occupational disease associated with working with cattle, sheep, or goats
coxiella burnetti - grows where in cell?: exclusively in phagolysosomal vesicle of cell
two variants of coxiella burnetti: (1) small cell variant (SCV) -- environmentally stable form

(2) large cell variant (LCV) -- metabolically active form
pathology of coxiella burnetti: respiratory (pneumonia) with high fever, which can last a LONG TIME; hepatomagaly and splenomegaly are common
HME: Human monocytic ehrilichiosis

HME is a tick borne infection caused by Ehrlichia chaffeensis
Sennetsu fever - caused by: Ehrlichia sennetsu
HGE - stands for - causative agent - tranmission by: Human granulocytic anaplasmosis

Anaplasma phagocytophilum

tick bite
Staphylococcaceae - gram stain: gram(+)
Staphylococcaceae - sugar fermentation: ferments glucose
what is the major test used to distinguish between virulent and avirulent species of Staphylococcaceae?: Coagulase test is the major test used to distinguish virulent (S. aureus; coagulase(+)) from avirulent (S. epidermidis, S. saprophyticus).
the characteristic lesion caused by staph is . . .: abscess
what is the major virulence factor of S. epidermidis?: biofilm formation

cause: Polysaccharide Intercellular Adhesin (PIA)
Protein A: e.g. Staphylococci

binds to Fc fragment of IgG subclasses preventing opsonization
MSCRAMMs - which species of Staph has it?: S. aureus
toxic shock syndrome toxin is a what?: superantigen
enterotoxin is a what?: superantigen
Staphylococci - what does toxin exfoliatin do?: cleaves desmosomes that hold the most superficial layer of skin together; results in blistering and loss of superficial skin layer
what is the most common cause of food poisoning?: S. aureus enterotoxin
what is the most common cause of pyogenic skin infections?: S. aureus
what is the major class of antibiotics used to treat staphylococcal infections?: B-lactams
what is the DOC for treating methicillin-resistant staphylococci?: vancomycin
from where do the staphylococci get resistance to antibiotics?: acquire individual genes, usually on plasmids
what organism is second to E. coli in causing UTIs in young sexually active women?: S. saprophyticus

Start Studying!

Deck Info

Number of cards 115