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Mikrobiyoloji Bulteni Jan 2021Rhodotorula species are yeasts that are common in the environment,but are not frequently encountered as an infectious agent in humans. Rhodotorula mucilaginosa,...
Rhodotorula species are yeasts that are common in the environment,but are not frequently encountered as an infectious agent in humans. Rhodotorula mucilaginosa, Rhodotorula glutinis and Rhodotorula minuta are the species that cause disease in humans. Although its isolation from mucosa is doubtful in terms of the presence of true infection, it is more frequently encountered in daily practice due to the increasing number of invasive procedures, immune system deficiencies caused by immunosuppressive drugs and diseases. R.mucilaginosa growth isolated from various clinical samples between 2000 and 2018 in a tertiary university hospital was presented in this case report. The first case was an 82-year-old man with chronic lung disease, hypertension, congestive heart failure and acute leukemia causing severe immunosuppression. Use of broad spectrum antibiotics, history of immunosuppressive therapy, presence of jugular catheter were the risk factors in this patient. R.mucilaginosa was isolated from blood culture while the patient was receiving fluconazole treatment for Candida albicans grown in urine culture and the patient died before starting the treatment. The second case was a 34-year-old female patient with congenital heart disease. Discharge was observed at the intracardiac defibrillator site of the patient, a temporary pacemaker was inserted, and she used broad spectrum antibiotics for a long time. When the yeast growth was reported in the blood culture, caspofungin treatment was initiated. Although the treatment was switched to amphotericin B lipid complex after the culture result was reported as R.mucilaginosa, the patient died after 12 hours. The third case was a 70-year-old woman with hypertension, dementia, diabetes mellitus and rheumatoid arthritis admitted to the intensive care unit due to cerebrovascular accident. She received different immunosuppressive treatments and had invasive procedures. R.mucilaginosa was isolated from the blood culture taken from the patient's catheter, and there was no growth in the blood culture obtained from the peripheral vein. Anidulafungin was started empirically, which was changed to amphotericin B lipid complex after the identification of the yeast. The patient died for various reasons 10 days after the antifungal treatment was stopped. Our last case was a 55-year-old woman with metastatic ovarian cancer and secondary ascites. Broad-spectrum multiple antibiotics were used and invasive procedures were performed. R.mucilaginosa and C.albicans were isolated from the urine of the patient who had a urinary catheter. No growth was detected from urine after changing the urinary catheter. Therefore, growths were evaluated as colonization, and fluconazole was administered for C.albicans due to the high risk of invasive infection. The patient was lost for different reasons. The development and diversity of the treatment methods lead to the emergence of some opportunistic infectious agents that were not observed previously. Rhodotorula species are one of the rare agents that have increased over the years. Rhodotorula species should be considered as the cause of an infection if no clinical response is obtained after echinocandin and/or fluconazole treatment in patients with long-term immunosuppression and invasive procedures. Data on clinical pictures, treatment responses, follow-up and treatment results of this rare yeast are still limited. This case series was presented to draw attention to the risk factors related to R.mucilaginosa infection/colonization, clinical characteristics of the patients, follow-up results and treatment options and to contribute to the literature.
Topics: Adult; Aged; Aged, 80 and over; Antifungal Agents; Fatal Outcome; Female; Fungemia; Humans; Male; Middle Aged; Mycoses; Rhodotorula; Tertiary Care Centers; Turkey
PubMed: 33590984
DOI: 10.5578/mb.20188 -
Microorganisms Jul 2023Sugar-rich waste streams, generated in very high quantities worldwide, constitute an important source of environmental pollution. Their eco-friendly conversions into a...
Sugar-rich waste streams, generated in very high quantities worldwide, constitute an important source of environmental pollution. Their eco-friendly conversions into a plethora of added-value compounds through the use of microbial fermentations is currently a very "hot" scientific topic. The aim of this study, was to assess the potential of single cell oil (SCO), microbial mass and citric acid (CA) production by non-conventional yeast strains growing on expired ("waste") glucose. Six yeast strains (. DSM 4444, NRRL YB-252, NRRL Y-27012, LFMB Y-20, ACA-DC 50109 and DSM 70296) were initially grown in shake flasks with expired glucose used as substrate under nitrogen limitation, in order to "boost" the cellular metabolism towards the synthesis of SCO and CA, and their growth response was quantitatively evaluated. Initial glucose concentration (Glc) was adjusted at . 50 g/L. Besides , all other yeast strains produced noticeable SCO quantities [lipid in dry cell weight (DCW) ranging from 25.3% / to 55.1% /]. Lipids of all yeasts contained significant quantities of oleic acid, being perfect candidates for the synthesis of 2nd generation biodiesel. The highest DCW production (=13.6 g/L) was obtained by DSM 70296, while both strains did not accumulate noticeable lipid quantities, but produced non-negligible CA amounts. The most promising CA-producing strain, namely ACA-DC 50109 was further studied in stirred-tank bioreactor systems, while the very promising DCW- and SCO-producing DSM 70296 was further studied in shake flasks. Both strains were grown on media presenting higher Glc concentrations and the same initial nitrogen quantity as previously. Indeed, grown at Glc = 85 g/L, produced DCW = 34.0 g/L, that contained lipid =34.1% / (thus SCO was =11.6 g/L). The strain ACA-DC 50109 in stirred tank bioreactor with Glc ≈ 105 g/L produced CA up to 46 g/L (yield of CA produced on glucose consumed; Y ≈ 0.45 g/g). Finally, in fed-batch bioreactor experiment, the significant CA quantity of 82.0 g/L (Y = 0.50 g/g) was recorded. Concluding, "waste" glucose proved to be a suitable substrate for a number of non-conventional yeast strains. ACA-DC 50109 produced significant quantities of CA while DSM 70296 was a very interesting DCW- and SCO-producing candidate. These strains can be used as potential cell factories amenable to convert glucose-based residues into the mentioned metabolic compounds, that present high importance for food, chemical and biofuel facilities.
PubMed: 37513034
DOI: 10.3390/microorganisms11071863 -
Frontiers in Cellular and Infection... 2021The occurrence of multidrug-resistant isolates and the increased mortality associated with invasive infections or outbreaks due to this species have been reported in...
The occurrence of multidrug-resistant isolates and the increased mortality associated with invasive infections or outbreaks due to this species have been reported in many healthcare settings. Therefore, accurate and rapid identification at the species level of clinical isolates as well as their timely differentiation as susceptible or resistant to antifungal drugs is mandatory. Aims of the present study were to implement the MALDI-TOF mass spectrometry (MS) Bruker Daltonics Biotyper database with spectrum profiles and to develop a fast and reproducible MS assay for detecting anidulafungin (AFG) resistance in isolates. After creation of main spectra, a score-oriented dendrogram was generated from hierarchical cluster analysis, including spectra of isolates from and other (, , , , and ) or non- () species. Cluster analysis allowed to group and classify the isolates according to their species designation. Then, a three-hour incubation antifungal susceptibility testing (AFST) assay was developed. Spectra obtained at null, intermediate, or maximum AFG concentrations were used to create composite correlation index matrices for eighteen isolates included in the study. All six resistant isolates were detected as resistant whereas 11 of 12 susceptible isolates were detected as susceptible by the MS-AFST assay. In conclusion, our MS-based assay offers the possibility of rapidly diagnosing and appropriately treating patients with infection.
Topics: Antifungal Agents; Candidiasis, Invasive; Cross Infection; Humans; Microbial Sensitivity Tests; Rhodotorula; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 33796487
DOI: 10.3389/fcimb.2021.645049 -
Medicine Jul 2023Rhodotorula glutinis is a rare cause of fungal peritonitis in peritoneal dialysis (PD) patients. The combination treatment between aggressive PD catheter replacement and...
RATIONALE
Rhodotorula glutinis is a rare cause of fungal peritonitis in peritoneal dialysis (PD) patients. The combination treatment between aggressive PD catheter replacement and adequate antifungal treatment is crucial in managing peritonitis due to fungal infection and onychomycosis.
PATIENT CONCERNS
A 37-year-old man PD patient presented with cloudy effluent, abdominal pain, and black debris in the lumen of his PD catheter. Twelve days before admission, the patient traveled for 10 days to a high-temperature country, Saudi Arabia, for purpose of accomplishing haj. From the physical examinations, there was an onychomycosis in his right toenail.
DIAGNOSES
The result of the dialysate cell count confirmed the evidence of peritonitis (i.e., cell count of 187 cells per µL, however with polymorphonuclear 31%). The dialysate culture indicated R glutinis, with no growth of bacteria. Fungal culture of his toenail scrapings was obtained and the result was Penicillium sp.
INTERVENTIONS
Based on the high clinical suspicion of fungal peritonitis, fluconazole intraperitoneal (IP) was immediately given on the first day in addition to empirical antibiotics, that is, cefazolin and gentamycin IP. His peritoneal catheter was simultaneously removed and reinserted on the 4th day of treatment. Since there was a sign of fluconazole resistance, fluconazole IP was switched into oral voriconazole, without any antimicrobial treatment intraperitoneally. After 21 days of voriconazole, oral itraconazole was given until 3 months for his onychomycosis.
OUTCOMES
Clinical improvement was seen on the effluent where the leucocyte count falls below 100 cells after 21 days of giving voriconazole.
LESSONS
This case report suggests the need for comprehensive evaluations of the risk for fungal infection in continuous ambulatory PD patients, especially those who live in a tropical country.
Topics: Male; Humans; Adult; Peritoneal Dialysis, Continuous Ambulatory; Onychomycosis; Fluconazole; Voriconazole; Mycoses; Peritonitis; Dialysis Solutions
PubMed: 37443482
DOI: 10.1097/MD.0000000000034199 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Nov 2020p-coumaric acid is an important natural phenolic compound with a variety of pharmacological activities, and also a precursor for the biosynthesis of many natural...
p-coumaric acid is an important natural phenolic compound with a variety of pharmacological activities, and also a precursor for the biosynthesis of many natural compounds. It is widely used in foods, cosmetics and medicines. Compared with the chemical synthesis and plant extraction, microbial production of p-coumaric acid has many advantages, such as energy saving and emission reduction. However, the yield of p-coumaric acid by microbial synthesis is too low to meet the requirements of large-scale industrial production. Here, to further improve p-coumaric acid production, the directed evolution of tyrosine ammonia lyase (TAL) encoded by Rhodotorula glutinis tal gene was conducted, and a high-throughput screening method was established to screen the mutant library for improve the property of TAL. A mutant with a doubled TAL catalytic activity was screened from about 10,000 colonies of the mutant library. There were three mutational amino acid sites in this TAL, namely S9Y, A11N, and E518A. It was further verified by a single point saturation mutation. When S9 was mutated to Y, I or N, or A11 was mutated to N, T or Y, the catalytic activity of TAL increased by more than 1-fold. Through combinatorial mutation of three types of mutations at the S9 and A11, the TAL catalytic activity of S9Y/A11N or S9N/A11Y mutants were significantly higher than that of other mutants. Then, the plasmid containing S9N/A11Y mutant was transformed into CP032, a tyrosine-producing E. coli strain. The engineered strain produced 394.2 mg/L p-coumaric acid, which is 2.2-fold higher than that of the control strain, via shake flask fermentation at 48 h. This work provides a new insight for the biosynthesis study of p-coumaric acid.
Topics: Ammonia-Lyases; Coumaric Acids; Escherichia coli; Propionates; Rhodotorula; Tyrosine
PubMed: 33244931
DOI: 10.13345/j.cjb.200122