PubMed · 7765141
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J M Luengo, M A Peñalva. 1994. Penicillin biosynthesis.. https://pubmed.ncbi.nlm.nih.gov/7765141/
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Polymerase chain reaction (PCR) products of nuclear 5.8S and internal transcribed spacer regions (ITS2) of rDNA from reference cultures of Acremonium obclavatum (a rarely recognized species first reported from India) were compared with cultures of Acremonium spp. isolated from Georgia, USA. Digestion of amplicons sequentially with Hinfl and Sau3AI divided the isolates into four restriction fragment length polymorphism (RFLP) groups. A representative isolate of primary colonizers of insulation facings from a building in Georgia appeared identical to the type culture of A. obclavatum, whereas other cultures from Indian soils showed variation in the ITS2 region that divided them into further subgroups. Reference cultures of A. kiliense (ATCC 14489) and A. strictum (ATCC 10141) and two additional isolates from metropolitan Atlanta, assigned to this latter species complex on a morphological basis, represented two additional RFLP groups both of which were distinct from the RFLP groups in A. obclavatum. A. kiliense and A. strictum could be placed into similar subgroups on the basis of morphological differences and distinct RFLP patterns.
PURPOSE: This study aimed to present two patients with delayed-onset, endogenous fungal keratitis after treatment for fungal endophthalmitis after cataract surgery. METHODS: The authors retrospectively reviewed the clinical course of two patients in whom deep stromal fungal keratitis developed 2 weeks and 3 months, respectively, after apparent successful aggressive therapy for fungal endophthalmitis. Before the onset of the keratitis, both patients underwent vitrectomies with intraocular injection of 7.5 to 10.0 mcg amphotericin B, as well as treatment with systemic fluconazole and topical antifungal therapy. In case 1, a pre-existing prosthetic intraocular lens and lens capsular bag were removed at the time of vitrectomy, whereas in case 2, the intraocular lens was left in place and a posterior capsulectomy was performed. RESULTS: The keratitis worsened in both patients, despite intensive systemic and topical antifungal therapy. Both patients underwent therapeutic penetrating keratoplasties. In case 1, this resulted in successful resolution of the infection and no recurrences 3 months after the transplant. The corneal transplant was complicated by an expulsive choroidal hemorrhage in the other patient. Fusarium solani was cultured from the initial vitrectomy specimen in patient 1, and although it was not cultured from the keratitis, septate hyphal elements were present on histopathologic examination. The causative organism in case 2 was Acremonium kiliense, which was cultured from both the original vitrectomy specimen and the deep corneal stromal infiltrate. CONCLUSIONS: Fungal organisms may not be eradicated completely from eyes with endophthalmitis despite aggressive therapy and apparent initial successful treatment. These patients need to be monitored for prolonged periods, and treatment should be reinitiated at the earliest sign of recrudescence of infection.
Nontraditional human pathogenic fungi, including Fusarium, Paecilomyces, and Acremonium species, have been increasingly documented as agents of infection in immunocompromised patients and, occasionally, in normal hosts. Although definitive identification of these fungi requires culture, they often can be identified provisionally in tissue sections by a combination of histologic features, including hyaline septate hyphae and characteristic reproductive structures known as phialides and phialoconidia. These morphologic characteristics, although familiar to mycologists, are easily overlooked by histopathologists; as a result, Fusarium species and Paecilomyces lilacinus are frequently misidentified in tissue sections as Aspergillus or Candida species. We identified 19 culture-proved cases of infection with species of Fusarium, Paecilomyces, or Acremonium; retrospectively reviewed histologic specimens stained by routine hematoxylin and eosin, Gomori methenamine silver, and/or periodic acid-Schiff stains; and delineated morphologic criteria that will help pathologists make a preliminary identification of these fungi by histopathology. Adventitious sporulation was found in 9 of 9 infections caused by Paecilomyces species, 7 of 10 infections caused by Fusarium species, and in the single case of infection caused by Acremonium strictum. Histologic recognition of these morphologies may help clinicians select appropriate initial antifungal treatment and manage the infection.