ANSWER TO PHOTO QUIZ
The Gram-stained preparation was forwarded to a centralized laboratory, where a microbiologist noted yeast with size variation along with several apparent interfaces (see Fig. 1 in the photo quiz, arrows) between blastoconidia that collectively resembled a “Tinker Toy” configuration. The primary Gram stain report was amended to “Abundant Yeast Forms Highly Suggestive of Cryptococcus Species.” Such an intervention provides evidence for the value of quality assurance mechanisms in paradigms of decentralized specimen processing and primary Gram stain interpretation (4). Subsequent culture of cerebrospinal fluid (CSF) propagated yeast on blood agar following 2 days of incubation in 5% CO2 at 35°C. Isolated colonies produced a positive urease test result and generated a biochemical-based identification of Cryptococcus neoformans (Vitek 2; bioMérieux). This result was consistent with a reported CSF cryptococcal antigen titer of 1,024.
The suggestive C. neoformans morphology exhibited in Fig. 1 in the photo quiz is likely representative of polysaccharide capsule-rich blastoconidia being oriented in adjacent fashion. Bottone (1) reported a Gram-stained population of C. neoformans organisms from a bronchoscopy specimen resembling lipoid bodies. While CSF cryptococcal antigen detection has sensitivity that equals or exceeds that of culture (2, 5), observation of C. neoformans via Gram stain cannot be discounted. In a limited series, Coovadia and Solwa (2) noted that 50% fewer cases of cryptococcal meningitis were detected by India ink preparations than by Gram stain. Dunbar et al. (3) reported a sensitivity of 85.2% for CSF Gram staining in 27 culture-positive cases of cryptococcal meningitis. Furthermore, moderate or greater leukocyte semiquantitation was noted in 15 (55.6%) of these Gram-stained preparations.
C. neoformans recovery was one component of an HIV infection/AIDS diagnosis derived from this patient encounter. Screening and confirmatory HIV serology yielded significant data; the absolute CD4+ T-lymphocyte count was 29/μl, and the HIV viral load was 1.03 × 105 copies. Oral thrush was diagnosed, along with Kaposi sarcoma in the right pubic area. The patient was treated with liposomal amphotericin B and flucytosine during the hospitalization and was discharged on HIV/AIDS prophylaxis (including fluconazole for cryptococcal disease).
(See page 3415 in this issue [doi:10.1128/JCM.00894-12] for photo quiz case presentation)
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