Does pre-exposure of Aspergillus fumigatus to voriconazole or posaconazole in vitro affect its virulence and the in vivo activity of subsequent posaconazole or voriconazole, respectively? A study in a fly model of aspergillosis.

OBJECTIVES: Voriconazole and posaconazole are effective as both prophylaxis and treatment for invasive aspergillosis (IA) in immunocompromised patients. Hence, it is important to determine whether Aspergillus pre-exposure to voriconazole or posaconazole diminishes subsequent posaconazole or voriconazole activity, respectively. METHODS: We used Aspergillus fumigatus (AF) 293 conidia with or without prior exposure to voriconazole or posaconazole [three serial passages on plates containing regular yeast extract-glucose (YAG) media, YAG+0.0625 mg/L voriconazole or YAG+0.025 mg/L posaconazole]. Toll-deficient Drosophila melanogaster flies were infected by injection, and 8 day survival was monitored. Following infection, flies were fed either regular food, food containing 1000 mg/L voriconazole (posaconazole-exposed conidia) or 1000 mg/L posaconazole (voriconazole-exposed conidia). Voriconazole and posaconazole concentrations in flies were confirmed by HPLC. RESULTS: AF inoculation resulted in 71% mortality 8 days post-infection (median survival 4 days). Prior conidial exposure to voriconazole or posaconazole did not affect mortality (73%, P = 0.8 for voriconazole pre-exposed and 76%, P = 0.49 for posaconazole pre-exposed). Voriconazole treatment post-infection had a protective effect, reducing mortality to 42% (P = 0.0002), while prior conidial exposure to posaconazole did not alter the protective effect of voriconazole (34% 8 day mortality, P = 0.35). Likewise, posaconazole treatment post-infection reduced mortality to 36%, while prior conidial exposure to voriconazole did not alter the protective effect of posaconazole (39% mortality, P = 0.92). Median fly homogenate concentrations of voriconazole and posaconazole were 0.44 and 2.05 mg/L, respectively. CONCLUSIONS: Prior exposure of AF to voriconazole or posaconazole did not affect the virulence of AF nor the subsequent activity of the alternate triazole in a Drosophila model of IA.

Fungal endophthalmitis in a tertiary care cancer center: a review of 23 cases.

Few data exist on the etiology, presentation, prognosis, and management of fungal endophthalmitis (FE) in cancer patients. FE cases were identified by reviewing the ophthalmology reports and microbiology cultures of patients at The University of Texas M. D. Anderson Cancer Center. We retrospectively reviewed the medical records and obtained information related to malignancy, fungal infection and its management, visual outcome, and mortality. We compared FE caused by Candida spp. (CE) to FE caused by molds (ME). Of the 102 cancer patients with a fungal infection for whom an ophthalmology consult was requested, 23 met the criteria for definite (N = 6) or probable (N = 17) FE (8 with CE, 15 with ME). All of the patients with ME had hematologic malignancies, whereas half of the patients with CE had solid tumor (P = .008). Only patients with CE had a history of surgery within 30 days of FE diagnosis (38%, P = .03). Fungal pneumonia [17 (74%)] and disseminated infection [14, (61%)] were common. The most common presenting symptoms were decreased vision [16 (70%)] and ocular pain [14 (61%)]. All treated patients received systemic antifungals (combination therapy in 72% of the cases). Seven patients (30%) underwent vitrectomy. Only one patient received intraocular injection of amphotericin B along with systemic antifungals. Four-week mortality was high [13 (57%)], especially in ME (73%, P = .04). Among the eight surviving patients where visual acuity could be assessed, visual outcome improved or remained stable in five (63%). FE in cancer patients occurs in the setting of severe, frequently disseminated opportunistic mycoses, is caused predominantly by hyalohyphomycetes, and is a marker for high 4-week mortality.

Zygomycetes hyphae trigger an early, robust proinflammatory response in human polymorphonuclear neutrophils through toll-like receptor 2 induction but display relative resistance to oxidative damage.

Human polymorphonuclear neutrophils (HPMNs) displayed attenuated hyphal damage associated with impaired O(2)(-) release following exposure to Rhizopus oryzae versus that with Aspergillus fumigatus. Exposure of HPMNs to R. oryzae hyphae resulted in upregulation in Toll-like receptor 2 mRNA and a robust proinflammatory gene expression with rapid (1-h) induction of NF-kappaB pathway-related genes.

Effects of vancomycin, teicoplanin, linezolid, quinupristin-dalfopristin, and telithromycin on murine gut colonization by Candida albicans.

Crl:CDI(ICR) BR adult mice were fed chow containing Candida albicans or regular chow. Both groups were subsequently given either antibiotics acting mainly against Gram-positive organisms or normal saline for 10 days. Stool cultures were performed before, at the end, and one week after discontinuation of treatment to determine the effects on the stool yeast concentration. Candida colonized mice treated with vancomycin, teicoplanin, linezolid, quinupristin-dalfopristin or telithromycin had higher colony counts of yeast in their stools than control Candida fed mice treated with saline. This increase was not statistically significant. Mice fed regular chow treated with the study drugs or saline did not have any yeasts in their stools. Dissemination of Candida was not observed in the visceral organs of any mouse.