Recovery of Coccidioides immitis from blood and abscess fluid using the BacT/Alert system

Abstract

We report the recovery of Coccidioides immitis from the blood and abscess fluid of two separate patients by using two automated blood culture systems. In the first case, an aspirate from a neck abscess containing C. immitis spherules was serially diluted and inoculated into liquid media used by the BacT/Alert and the Bactec NR660 blood culture systems. BacT/Alert bottles inoculated with 10 5, 10 4, 10 3, 10 2, 10, and two spherules produced a positive signal at 19, 24, 35, 42, 57, and 62 h postinoculation, respectively. Bactec NR660 bottles containing >10 2 spherules and 10 spherules produced a positive signal after approximately 72 and 96 h of incubation, respectively. In the second case, a blood specimen incubated in BacT/Alert blood culture broth was signaled positive after 82 h of incubation. No organisms were detected by Gram stain of the broth, but C. immitis grew after blind subculture. Our observations demonstrate that these rapid blood culture systems are capable of supporting growth of C. immitis. To our knowledge, this report is the first to detect C. immitis by these blood culture systems.