PCR-Based Detection of Bacillus anthracis in Formalin-Fixed Tissue from a Patient Receiving Ciprofloxacin

We demonstrate that Bacillus anthracis may be detected from a formalin-fixed, paraffin-embedded biopsy specimen, even after the patient has received antibiotic treatment. Although traditional PCR methods may not be sufficiently sensitive for anthrax detection in such patients, cycle numbers can be increased or PCR can be repeated by using an aliquot from a previous PCR as the template. Bacillus anthracis, the causative agent of anthrax, has been postulated to be a likely agent of biological warfare or terror-ism because of its physical properties and its virulence factors (8). Nonetheless, anthrax had not been encountered in the United States as a weapon of terror until the fall of 2001 (2). Current reports have documented 22 cases of anthrax that have met the Centers for Disease Control and Prevention (CDC) case definition; 12 cases (7 confirmed and 5 suspected) were of the cutaneous form (3, 10). Due to variation in symp-toms and findings in cases of cutaneous anthrax, a definitive diagnosis of infection requires identification of the organis