Anaerobic Infections Flashcards
<p>What is an anerobe?</p>
<p>organisms that requre reduced O2 for growth</p>
<p>i.e. fail to grow on the surface of solid media in 10% CO2 in air</p>
<p>What is the concept of colonization resistance?</p>
<p>concept that anaerobic bacteria occupy ecological niches that would otherwise be filled with potentially pathogenic organisms, by depleting oxygen & other nutrients, as well as producing various enzymes & toxic products.</p>
<p>What are the common characteristic of anaerobic infections?</p>
<p>-Frequently polymicrobial.</p>
<p>-Gas forming & foul smell.</p>
<p>-Failure to grow if not cultured properly under anaerobic conditions:</p>
<p>-do not respond to some usual antibiotics</p>
Why are many anaerobic infections diagnosed late or not at all?
They fail to grow if not cultured properly under anaerobic conditions
<p>What toxins are produced by C. difficile?</p>
<p><strong>-Toxin A: </strong>watery diarrhea</p>
<p><strong>-toxin B: </strong>cytotoxic to colon cells (degrades actin)</p>
<p><strong>-Binary toxin: </strong>increased virulence & resistance</p>
What is the most common cause of marked leukocytosis?
-C. difficile
How is C. difficile diagnosed?
-PCR-based toxin gene testing
<p>What is the most common scenario for botulism?</p>
<p>-Infants ingest spores, usually from <strong>honey</strong></p>
<p>-progresses for 1-2 weeks</p>
<p><strong>"floppy baby" </strong>syndrome</p>
<p>What are the symptoms of botulism?</p>
<p>-blurred vision</p>
<p>-diplopia</p>
<p>-ptosis</p>
<p>-expressionless facies</p>
<p>-regurgitation</p>
<p>-dysphagia</p>
<p>What are the important clinical features of botulism?</p>
<p>-No fever</p>
<p>-Symmetrical neurological manifestations</p>
<p>-Patients remain responsive</p>
<p>-Heart rate is normal or slow</p>
<p>-Sensory deficits do not occur</p>
<p>How do we treat botulism?</p>
<p>-botulism antitoxin</p>
<p>-only binds free toxin, current symptoms will not be reversed until later</p>
<p>-Human botulism immunoglobulin <strong>(infant botulism)</strong></p>
When does Clostridium tetani infection occur?
-acute injuries (punctures & lacerations)
<p>What are the four clinical forms of disease caused by tetanus?</p>
<p>-localized tetanus</p>
<p>-facial tetanus <strong>(risus sardonicus)</strong></p>
<p>-neonatal tetanus</p>
<p>-generalized tetanus</p>
What symptom does generalized tetanus generally begin with?
-trismus (lockjaw)
<p>How do we treat tetanus patients?</p>
<p>-Benzos for symptom relief -</p>
<p>abx: metronidazole or penicillin</p>
<p>-alpha and beta blockers</p>
<p>-passive & active immunization</p>
<p>What does Porphyromonas gingivalis cause?</p>
<p>-gingivitis</p>
<p>What are the 3 major aspiration syndromes?</p>
<p>-chemical pneumonitis 2' to gastric acid burns</p>
<p>-bronchial obstruction 2' to particulate matter</p>
<p>-bacterial aspiration syndromes</p>
<p>Is aspiration pneumonia more common in the right or left lung?</p>
<p><strong>Right </strong></p>
<p>-right main stem bronchus comes off at less of an acute angle</p>
<p>What are the Clinical Presentation of Anaerobic Pleuropulmonary Infections?</p>
<p>-Relatively insidious onset;</p>
<p>-Low-grade fever, malaise, weight loss, pleuritic chest pain & cough;</p>
<p>-Poor dental hygiene;</p>
<p>-Large amounts of sputum with foul taste:</p>
<p>*Odor of patient’s breath can be very <strong>offensive</strong>!</p>
<p>How do we diagnose aspiration pneumonia?</p>
<p>Sputum gram-stain is the diagnostic procedure of choice</p>
<p>*Anaerobic culture of expectorated sputum is unreliable, because of oral contamination.</p>
What is a buzzword for actinomyces?
sulfur granules
<p>What events can result in microorganisms within the peritoneal cavity?</p>
<p>-Organ perforation (ulcers, appendicitis, diverticulitis, etc.);</p>
<p>-Organ trauma (bullet, knife) or iatrogenic causes (“incidental” surgical accidents);</p>
<p>-Intraabdominal ischemia;</p>
<p>-Extension of inflammation or a preexisting infection.</p>
<p>What is 1' or spontaneous bacterial peritonitis?</p>
<p>-infections of the peritoneal cavity without an evident source</p>
<p>-usually caused by a single species of bug</p>
<p>When does spontaneous bacterial peritonitis occur?</p>
<p>-usually in kids with nephrotic syndrome, and adult cirrhotics</p>
<p><strong>Children </strong>= S. pneumoniae</p>
<p><strong>Adult </strong>= E. coli</p>
<p>What organisms are usually involved in pancreatic abscesses?</p>
<p>-E. coli</p>
<p>-enterococcus</p>
<p>-other enterobacteriaceae</p>