3. Diag anthrax

contagious

What are the pathognomonic postmortem findings of anthrax?

Hemorrhages, blackberry jam splenomegaly, poorly clotted dark blood, incomplete rigor mortis

Where should necropsies for anthrax be performed?

Only in diagnostic institutes

What is specific for Bacillus anthracis capsule visualization?

McFadyean’s staining: pink capsule, dark blue cells; Giemsa staining: red capsule, dark red cells

How can Bacillus anthracis be cultured?

Turbinate bone spores on nutrient agar/broth under aerobic conditions at 37°C

What is a key differentiating feature of Bacillus cereus in culture?

Hemolytic colonies on 5% blood agar

Which Bacillus species can create capsules both in vivo and in vitro?

Bacillus cereus and Bacillus subtilis

How can old specimens of Bacillus anthracis be identified?

Special restrictive nutrient medium (PLET) or animal inoculation followed by postmortem capsule staining and culture

What is the Ascoli test used for?

Detecting Bacillus anthracis antigen in fluid using antibodies in serum, positive results cause precipitation

What are the limitations of the Ascoli test?

Low sensitivity and specificity

Why is immunofluorescence not viable for anthrax detection?

Cross-reactivity interferes with results

Are there highly specific serological tests for anthrax?

No

What is PCR used for in anthrax diagnosis?

Confirmation of virulence