Term
examples of obligate anaerobies |
|
Definition
|
|
Term
Mechanism of anaerobe discovery in culture and how it is preserved |
|
Definition
- dependent on specimen handling and culture techniques
- exclude air from specimen
- anaerobic transport media can be utilized
- specimen should be promptly delivered to lab
- special jar, chamber to culture where oxygen can be excluded
|
|
|
Term
Where would we find anaerobic bacteria in normal body flora |
|
Definition
- mucosal surfaces
- oral cavity
- GI tract (dominate in distal ileium and colon while aerobes found more in proximal GI tract)
- upper resp. tract
- femal GU tract
|
|
|
Term
medically important anaerobes in the flora |
|
Definition
- gram neg. rods- bacteriods, fusbacterium, prevotella
- gram pos. rods- clostridia (spore forming), actinomyces (non spore forming)
- gram pos. cocci- peptococcus, peptostreptococcus
- gram neg. cocci- veillonella
|
|
|
Term
place in body with primarily aerobic flora |
|
Definition
|
|
Term
predisposing conditions/clinical characteristics of anaerobic infections |
|
Definition
- secondary invaders from normal flora
- predisposing conditions
- tissue destruction- tumor, trauma, vascular insufficiency (all lead to tissue anoxia and low oxygen tension)
- antecedent aerobic infection
- complex polymicrobial
- foul smell
- gas in tissue
- abscess formation
|
|
|
Term
cause of intraabdominal sepsis |
|
Definition
secondary to breach in colon |
|
|
Term
sources of intra-abdominal or pelvic infection |
|
Definition
- perforated appendix or diverticulum
- perforated colon cancer
- gunshot to abdomen
- post-op infection
|
|
|
Term
pathophysiology of intraabdominal sepsis according to rat model and what can prevent the various stages from occuring |
|
Definition
- breach in colon
- leads to fecal material being released into peritoneal cavity
- contains many anaerobic species
- usually Bacterioides fragilis and E coli
- two stages
- peritonitis stage- 40% mortality (dominated by E coli)
- prevent death via antibiotics
- abscess stage after 7-14 days (dominated by B. fragilis)
- must use antibiotics that will work against this bacteria to prevent abscess formation
|
|
|
Term
Ludwig's angina (cause, def., predisposing factors) |
|
Definition
- definition- infection in submandibular space (sublingual, submylohyoid)
- predisposing factors
- odontogenic infection
- trauma
- mandibular fracture
- foreign bodies
- neoplasm
- causative agents
- mixed oral aerobes, anaerobes
- sometimes S. aureus
|
|
|
Term
Clinical features of Ludwig's angina |
|
Definition
- mouth pain
- drooling
- dysphagia
- resp. distress
- hot potato voice
- edema on floor of mouth with swelling and displacement of tongue post. and sup.
- woody tender swelling of suprahyoid region of the neck
|
|
|
Term
predisposing conditions of anaerobic pneumonia/ lung abscess |
|
Definition
- altered consciousness
- alcoholism
- general anesthesia
- drug overdose
- esophageal dysfunction
- tonsillectomy/tooth extraction
|
|
|
Term
lung abscess clinical features and tx |
|
Definition
- present with cough, fever, coppious foul smelling sputum
- chest X ray with cavitation with air/fluid level
- sputum gram stain shows mixed gram negative and positive organisms
- increased incidence of penicillin R
- clindamycin most effect
|
|
|
Term
reliable diagnosis specimens in bacterial pulmonology infections |
|
Definition
- blood cultures
- direct lung punctures
- thoracotomy aspirates
- empyema fluid
- percutaneous transtracheal aspiration
- bronchospcopy with protected brush
|
|
|
Term
|
Definition
- mix of anaerobes and aerobes
- shown that anaerboes were by far dominant
- common aerobes- Strep. pneumonia, S. aureus, E coli
- common anaerobes- Clostridium, Bacteriocides
|
|
|
Term
predisposing factors to brain abscess |
|
Definition
- otitis media
- sinusitis
- dental infection
- pneumonia
- abdominal/pelvic infection
- endocarditis (S aureus, Strep.)
|
|
|
Term
etiology of brain abscess |
|
Definition
- primarly caused by oral flora
- 85% anaerobe
- gram positive cocci
- Fusobacterium, Bacteroids
- in setting of endocarditis- S aureus, Viridans Strep
|
|
|
Term
clinical presentation of brain abscess |
|
Definition
- subacute symptoms
- fever, altered sensorium
- focal neurologic defects
- increase intracranial P, papilledema
|
|
|
Term
diagnosis of brain abscess |
|
Definition
- imaging via CT, MRI
- aspiration and gram stain, culture
- blood culture
- CI: lumbar puncture due to risk of increased intracranial P
|
|
|
Term
examples of localized anaerobic soft tissue infections |
|
Definition
- DM, vascular ulcures
- decubitus ulcers
- human bites
- hydradenitis suppurtiva
- Meleney synergistic gangrene
|
|
|
Term
examples of diffuse infections in soft tissue caused by anaerobes |
|
Definition
- anaerobic cellulitis
- necrotizing faciitis
- synergistic necrotizing cellulitis
- myonecrosis syndromes
|
|
|
Term
risk factors of DM soft tissue infection |
|
Definition
- neuropathy- loss of sensation
- vasculopathy- impaired blood flow
- immunopathy- impaired WBC function
|
|
|
Term
compare and contrast the two types of necrotizing fasciitis |
|
Definition
- mixed
- rapid progression, substantial mortality
- maybe subtle skin findings initially
- pain out of proportion to clinical findings
- group A strep
- more rapid progress, higher mortality
- may have no skin findings
- even more painful
|
|
|
Term
Epidemiology, char, toxicology of clostridia |
|
Definition
- epidemiology- ubiquitous in soil, water, sewage (part of normal flora)
- char- gram positive spore forming bacilli
- produce multiple toxins
- cytotoxins
- enterotoxins
- neurotoxins
|
|
|
Term
Clostrium perfringes (toxins, what it causes) |
|
Definition
- gas gangrene (Clostridial myonecrosis)
- 12 toxins/enzymes
- alpha toxin- via PLC, causes hemolysis (cytotoxic)
- food poisoning
- enterotoxin (heat labile toxin released during spore formation)
|
|
|
Term
clinical features of gas gangrene |
|
Definition
- clincial syndrome char. by severe pain and marked toxicity
- patients alert with impending sense of doom
- usually with antecedent trauma
|
|
|
Term
|
Definition
make dx clinically (never via microbiologic dx)
palpable if cause is C repitus
visualize via X ray, CT, MRI |
|
|
Term
causative agents of gas in tissues |
|
Definition
- anaerobes- Bacteroids, Clostridia, anaerobic strept.
- aerobes if high glucose
|
|
|
Term
danger signs of gas gangrene |
|
Definition
- severe pain
- severe systemic toxicity
- hypoesthesia
- ecchymoses or bullae
- soft tissue gas
- rapid extension
|
|
|
Term
Char., toxins of C. tetani |
|
Definition
- char.- anaerobic spore forming rod
- tetanospasmin- dimeric toxin
- neurotoxin (produced during stationary phase of growth)
- block inhibitory transmitter release at inhibitory synapse in spinal cord (ex: GABA, Gly)
|
|
|
Term
different types of tetanus and incubation period |
|
Definition
- incubation- seven days usually (0-90 day range)
- localized- muscle spasms localized to area of primary infection
- generalized- lockjaw, persistent back spasm, autonomic dysfunction
- neonatal- associated with infection of umbilical stump (mortality 90%)
|
|
|
Term
|
Definition
- wound debriment
- antibiotics
- passive immunization (tetanus IG)
- active immunization (tetanus toxoid)
|
|
|
Term
|
Definition
- characteristics- spores heat resistent, present in soil
- VF- botulism toxin
- type A, B, E
- indiv. isolates prod. only one toxin
- type E with aquatic animals
- block ACh release at motor end plates leading to paralysis
|
|
|
Term
botulism (sources and what associated with) |
|
Definition
- food born (preformed toxin)
- associated with ingestion of home and commercially canned foods
- infant toxin formed in vivo (MOST COMMON IN US)
- associated with honey ingestion
- wound toxin formed in vivo
- associated with IV drug use
|
|
|
Term
foodborn botulusm (clinical symptoms, incubation period) |
|
Definition
- anticholinergic effects- vomitting, dry mouth, dilated pupils
- CN paralysis
- descending flacid motor paralysis
- incubation: 12-36 hrs
|
|
|
Term
|
Definition
- remove toxin (gastric lavage, wound debridment)
- resp. support
- polyvalent equine antitoxin
|
|
|
Term
Where are most of botulism cases in US? Why |
|
Definition
- Alaska
- traditional native foods ferment in conditions that favor spore forming bacteria
|
|
|
Term
|
Definition
- Char- spore forming, gram positive anaerboic bacillus (asymp. in colonic floor of most people)
- spores persist for months in envir.
- VF- enterotoxin (A) and cytotoxin (B)
|
|
|
Term
C difile associated with what clinical syndrome |
|
Definition
antibiotic associated diarrhea |
|
|
Term
Antibiotic associated colitis (pathogenesis) |
|
Definition
- antibiotic therapy
- up to six weeks after, alter colonic microflora
- germination of C dificile spores
- release toxin A and B from spore forming coat
- colonic mucosal injury and inflammation
|
|
|
Term
clinical manifestations of C difficile associated colitis |
|
Definition
- symp.
- profuse watery diarrhea
- abdominal pain
- leukocytosis
- fever
- complication
- dehydration
- electrolyte disturbance
- shock
- toxic megacolon
- reactive arthritis
|
|
|
Term
dx of C difficile associated diarrhea |
|
Definition
- endoscopic appearance: pseudomembranes
- fetal leukocytes in 50%
- cytotoxic assay
- ELISA for toxin A or B
- NOT culture
|
|
|
Term
clinical management of C difficile associated colitis |
|
Definition
- discontinue causative antibiotic
- initiate effective antibiotic
- metronidazole
- oral vancomycin
- rifaximin
- toxin bindin resins
|
|
|