Clostridia, Coryne, Listeria, Staph Flashcards
Look into C.tetani toxin and treatment
What toxins does C.perfringens make
- Lecithinase: an alpha-toxin breaks down lecithin
-enterotoxins
what are the symptoms of C.perfringens?
Similar to B.cereus: nausea, vomitting, fever, self limiting
Where does Clostridia live?
typically in the soil or feces. Spores are the main vector
What bacteria causes gas production in the area of infection (wound)? how does this help the bacteria ?
-Clostridia
-interferes with blood supply
-tissue distention
-necrotizing toxin and hyaluronidase secretion
-tissue necroses -> hemolytic anemia -> toxemia
What is gas gangrene? what is it caused by ?
- Clostridial myonecrosis
- Caused by a mix of clostridia, cocci, and gram-negative organisms eating tissue
-characterized by gas production, distention
What is the clinical presentation of clostridium in an contaminated wound and food poisoning? where would you collect specimins
What tests can be used to ID clostridia?
-agar: hemolysis, anaerobic
-typcial signs: gas production during carb ferm test, lecithinase, activity
-ELISA for specific toxin
-PCR
What is treatment of invasive clostridia?
-removal of infected tissue
- use of antimicrobial drugs (penicillin)
-Hyperbaric oxygen: detoxification
- treatment with anti-toxins
- preventative measures: containment of wound
What are three geneus of aerobic non-spore forming gram-positive bacteria
Corynebacterium, Listreia, and Erysipelotthrix
What are the two geneus of gram-positive, spore forming aerobic bacteria?
What are the general characteistics of Corynebacterium
-aerobic
-non-sporeforming
-forms clubbed ends at the end of the rods = irregular rod shape
- High G-C content
-small
How do you ID CoryneBacteria diphtheriae?
-aniline dye/monochromatic dye is used to stain the bacteria, causing the clubbed ends to be purple and the body to be green
How does Coryne look under blood agar? What special agar can you use to help?
Small, granular, grey, irregular
-Tellurite agar: brown-black with brown-black halo (halo is unique)
What are the two types of Diptheria? How is it spread?
What is the toxin that C.diphtheriae produce? how does it work?
-small and breaks into fragments held by disulfide bond
FINISH
What is the pathology of respiratory diphtheria
-toxin is absorbed into membranes: destroys epithemium and starts inflammation response
-psuedomembrane forms: made of necrotic tissue, RBC, and WBC formed at the back of the throat
-Enlarged lymphnodes : “bull neck” due to edema of neck
-Toxin can disseminate systemically -> leads to paralysis
What is the pathology of cutaneous diphtheria?
-membrane forms around infected wound
-little toxin is absorbed due to skin
What is the clinical findings for resp diptheria
-Sore throat
-low-grade fever
-prostration
-dyspnea
-systematic irregulatiries: cardiac, vision, speech, swallowing, movement
How do you ID C.diphtheriae (3)? where do you get the samples from the patient(2)?
-take samples before antimicrobials
-swabs from nose, throat or lesion under visible membrane
-Stain -> clubed rods
-selective agars: tellurite
-toxin testing: antitoxin tests, PCR, ELISA
What factors cause resistence to C.diphtheria?
How do you treat diphtheria?
-Prevent toxin-producing baccteria
-antimicrob: penicillin, erythromycin
- specific anti-toxin at infection site: stops disease progression
What is a convalescent carrier?
A carrier of a pathogen who sheds pathogens for awhile after reported infection
What are the general characterisitcs of Listeria?
-ubiquitious: soil, vegitation, sewage, water, silage, slaughterhouse waste, healthy animals
-Hardy: large temp range, pH and O2 amount alowed for growth. Salt tolerant(halotolerant)
