Infectious disease--Diebel Flashcards
What micoorganisms are associated with Necrotizing Fasciitis?
Streptococcus pyogenes (gram + cocci)
and
Clostridium perfringens (gram + bacilli)
What organisms are associated with Acute Infectious Arthritis?
Staphylococcus aureus (gram + cocci)
and
Neisseria gonorrhoeae (gram - diplococci)
What microoganism is associated with Osteomyelitis?
Staphylococcus aureus (Gram + cocci)
Salmonella typhi (Gram - bacilli)
Pasteurella multocida (Gram - coccobacilli)
What microorganisms are associated with Myositis?
Clostridium perfringens (gram + bacilli)
Staphylococcus aureus (gram + cocci)
Coxackievirus A & B
ssRNA (+)
Group IV
Nonsegmented
Icosahedral
non-enveloped
picornaviridae
Coxsackie B virus accounts for 50% of cases of viral myocarditis
Dengue Fever Virus
ssRNA (+)
Group IV
Flavivirdae
Enveloped
Icosahedral
“breakbone fever” (fever with hemorrage and shock)
High fever (103), a swollen lower left leg with multiple necrotic-appearning lesions, and pain while walking.
What might this be?
What lab values would you expect?
walking pain = osteomyelitis
microorganisms = Staph aureus (Pseudomonas aeruginosa and streptococcus pyogenes less likely)
Expect high WBC (>11,000) and ESR
Gram stain and cultures to definitively diagnose
Rapid onset of skin discoloration, high fever, high HR, and low BP.
What might it be?
Labs?
Necrotizing fasciitis
Streptococcus pyogenes most likely. (Clostridium perfringens is another possibility)
high ESR, high CRP, high WBC
should see a high level of banded neutrophils
Start IV antibiotic and get surgical consultation fast!!
Necrotizing fasciitis
Deeper tissue injury, usually from anaerobic bacteria or S. pyogenes.
Results in crepitus from methane and C02 production.
“Flesh-eating bacteria.” Causes bullae and a purple color to the skin.
myositis
infection of the muscle that leads to muscle inflammation.
bacteremia
the presence of bacteria in the bloodstream
viremia
the presence of virus in the bloodstream
septicemia
bloodborne systemic infection. can lead ot spread of the infectious organism to other tissues, massive inflammation, septic shock, and rapid death. Associated with bacerial infections
almost always begin as a local infection in a specific organ
bacteremia and septicemia
nectrotizing fasciitis
deep tissue infection that destroys tissue below skin and above muscle. streptococcus pyrogenes and clostridium perfringens
WBCs and WBC count
Normal range = 4,500 to 11,000 cells/ml
C-Reactive Protein
produced in liver
IL-6 by innate immune response travels to the liver and stimulates the production of C-Reactive Protein
foul smeeling body fluid might suggest what?
obligate anaerobe infection
Acute infectious arthritis
staphylococcus aureus and neisseria gonorrhoeae
Osteomyelitis
Caused by bacteria, mycobacteria, or fungi. Common symptoms are localized bone pain and tenderness.
Diagnosis is by imaging studies and cultures.
Treatment is with antibiotics and surgery. Staphylococcus aureus (>50%), Salmonella typhi, Pasteurella multocida
Myositis
Infections of muscles leading to inflammation.
Many forms including clostridial myositis, viral infections, and helminth infections. Although myalgia can occur in most of these infections, severe muscle pain is the hallmark of pleurodynia (coxsackievirus B), trichinellosis, and bacterial infection. Clostridium perfringens, Staphylococcus aureus, Coxsackievirus A & B, Dengue Fever Virus
Neisseria Gonorrhoeae timescale
first week: detectable in blood
after that: gradually disappears from the bloodstream and takes residence in synovial fluid.
Most necrotizing fasciitis cases result from infection with ______________ or a mixture of aerobic and anaerobic bacteria such as …
group A streptococcus (Streptococcus pyogenes); such as Bacteroides species.
Gas gangrene
usually follows sever penetrating injuries.
Typically caused by Clostridium perfringens. This is a type of myositis!
