Fungal and bacterial co-infections of the respiratory tract among patients with COVID-19 hospitalized in intensive care units.

Backgrounds: The pandemic of COVID-19 has created a global public health crisis. ICU patients with COVID-19 are prone to infections of bacterial and/or fungal origins due to several risk factors. Consequently, the current study was conducted to evaluate the frequency, demographic characteristics, underlying conditions, and etiologic agents of fungal and bacterial co-infections of the respiratory tract among ICU patients with COVID-19 in Iran. Materials and methods: From May to October 2020, sputa and endotracheal aspirates were collected from ICU patients hospitalized with COVID-19 who also were suspected of bacterial and/or fungal co-infections according to inclusion criteria. The etiologic agents of bacterial co-infections were identified using the Vitek 2 identification method. For fungal identification, all samples were analyzed by direct microscopy using KOH 10% and culture. Furthermore, all isolates were subjected to sequencing method. Results: A total of 73 lung specimens were obtained from patients who met the inclusion criteria. Of these, in 15 cases (20.54%) fungal and/or bacterial co-infections were confirmed. Males were more infected (73.33%) and all of them were between 49 and 79 years. Candida albicans (n = 8, 61.53%) and Klebsiella pneumoniae (n = 5, 38.46%) were the most frequent etiologic agents related to fungal and bacterial co-infections, respectively. Pneumonia (n = 15, 100%) and diabetes mellitus (n = 8, 53.33%) were documented as the most prevalent underlying conditions. In the current study, 3 out of 15 patients (20%) died. Conclusion: The frequency of bacterial co-infections of the respiratory tract in ICU patients hospitalized with COVID-19 was relatively high. According to the results, one of the causes of death of these patients could be a secondary infection.

Peritoneal dialysis-associated peritonitis caused by Exophiala spinifera: A case report and review of literature.

Exophiala spinifera is a black ascomycetous yeast and is responsible for phaeohyphomycosis. We provide the first case report of peritoneal dialysis (PD)-associated peritonitis in a female patient with progressive impairment of visual capacity. The infection was caused by a cutaneous infection of her hands. The patient responded well with PD catheter removal and 2-week antifungal medication. This case emphasizes the importance of hand hygiene and regular eye evaluation in preventing environment-bound infection in patients on PD. 2012 Elsevier Ltd. All rights reserved.

Enhanced production of cordycepin in Ophiocordyceps sinensis using growth supplements under submerged conditions.

Cordycepin is a crucial bioactive compound produced by the fungus Cordyceps spp. Its therapeutic potential has been recognized for a wide range of biological properties such as anticancer, anti-diabetic, antidepressant, antioxidant, immunomodulation, etc. Moreover, its human random clinical trials depicted a promising anti-inflammatory activity that reduced the airway inflammation remarkably in asthmatic patients. But its overexploitation and low production of cordycepin in naturally growing biomass are insufficient to meet its existing market demand for its therapeutic use. Therefore, strategies for enhancement of cordycepin production in Cordyceps spp. are warranted. However, specifically, wild type Ophiocordyceps sinensis possesses a very low content of cordycepin and has restricted growth in natural mycelial biomass. To overcome these limitations, this study attempted to enhance cordycepin production in its mycelial biomass in vitro under submerged conditions by adding various growth supplements. The effect of these growth supplements was evaluated by reversed-phase high-performance liquid chromatography (RP-HPLC) which demonstrated that among nucleosides- hypoxanthine and adenosine; amino acids-glycine and glutamine; plant hormones- 1-naphthaleneacetic acid (NAA) and 3-indoleacetic acid (IAA); vitamin-thiamine (B1) from each group of growth supplements yielded a higher amount of cordycepin with 466.48 ±â€¯3.88, 380.23 ±â€¯1.78, 434.97 ±â€¯2.32, 269.78 ±â€¯2.92, 227.61 ±â€¯2.34, 226.02 ±â€¯1.69 and 185.26 ±â€¯2.35 mg/L respectively as compared to control with 13.66 ±â€¯0.64 mg/L. Further, at the transcriptional level, quantitative real time-polymerase chain reaction (qRT-PCR) analysis of genes associated with metabolism and cordycepin biosynthesis depicted significant upregulation of major downstream genes- NT5E, RNR, purA, and ADEK which corroborated well with RP-HPLC analysis. Taken together, the present study identified growth supplements as potential precursors to activate the cordycepin biosynthesis pathway leading to improved cordycepin production in O. sinensis.

The development of animal infection models and antifungal efficacy assays against clinical isolates of Trichosporon asahii, T. asteroides and T. inkin.

The present study developed Galleria mellonella and murine infection models for the study of Trichosporon infections. The utility of the developed animal models was demonstrated through the assessment of virulence and antifungal efficacy for 7 clinical isolates of Trichosporon asahii, T. asteroides and T. inkin. The susceptibility of the Trichosporon isolates to several common antifungal drugs was tested in vitro using the broth microdilution and the E-test methods. The E-test method depicted a lower minimal inhibitory concentration (MIC) for amphotericin and a slightly higher MIC for caspofungin, while MICs observed for the azoles were different but comparable between both methods. All three Trichosporon species established infection in both the G. mellonella and immunosuppressed murine models. Species and strain dependent differences were observed in both the G. mellonella and murine models. T. asahii was demonstrated to be more virulent than the other 2 species in both animal hosts. Significant differences in virulence were observed between strains for T. asteroides in the murine model. In both animal models, fluconazole and voriconazole were able to improve the survival of the animals compared to the untreated control groups infected with any of the 3 Trichosporon species. In G. mellonella, amphotericin was not able to reduce mortality in any of the 3 species. In contrast, amphotericin was able to reduce murine mortality in the T. asahii or T. inkin models, respectively. Hence, the developed animal infection models can be directly applicable to the future deeper investigation of the molecular determinants of Trichosporon virulence and antifungal resistance.