Candida utilisfungaemia following endoscopic intervention on ureteral stent in a kidney transplant recipient: Case report and a review of the literature

Candida utilis candidaemia in premature infants: a retrospective single-centre study

This retrospective study was conducted in a neonatal intensive care unit in Beijing. Patients whose blood culture yielded Candida utilis during hospitalisation from January 2009 to December 2017 were enrolled. Thirteen preterm infants of median gestational age 29.85 weeks were included. Laboratory tests on the day of onset showed thrombocytopaenia in 11 patients, granulocytopaenia in eight and elevated C-reactive protein in seven. No fungal endophthalmitis, renal infection, carditis or involvement of other end organs was observed in any of the cases. All 13 patients were cured after fluconazole therapy.

An integrated transcriptomic and metabolic phenotype analysis to uncover the metabolic characteristics of a genetically engineered Candida utilis strain expressing δ-zein gene

Introduction

Candida utilis (C. utilis) has been extensively utilized as human food or animal feed additives. With its ability to support heterologous gene expression, C. utilis proves to be a valuable platform for the synthesis of proteins and metabolites that possess both high nutritional and economic value. However, there remains a dearth of research focused on the characteristics of C. utilis through genomic, transcriptomic and metabolic approaches.

Methods

With the aim of unraveling the molecular mechanism and genetic basis governing the biological process of C. utilis, we embarked on a de novo sequencing endeavor to acquire comprehensive sequence data. In addition, an integrated transcriptomic and metabolic phenotype analysis was performed to compare the wild-type C. utilis (WT) with a genetically engineered strain of C. utilis that harbors the heterologous δ-zein gene (RCT).

Results

δ-zein is a protein rich in methionine found in the endosperm of maize. The integrated analysis of transcriptomic and metabolic phenotypes uncovered significant metabolic diversity between the WT and RCT C. utilis. A total of 252 differentially expressed genes were identified, primarily associated with ribosome function, peroxisome activity, arginine and proline metabolism, carbon metabolism, and fatty acid degradation. In the experimental setup using PM1, PM2, and PM4 plates, a total of 284 growth conditions were tested. A comparison between the WT and RCT C. utilis demonstrated significant increases in the utilization of certain carbon source substrates by RCT. Gelatin and glycogen were found to be significantly utilized to a greater extent by RCT compared to WT. Additionally, in terms of sulfur source substrates, RCT exhibited significantly increased utilization of O-Phospho-L-Tyrosine and L-Methionine Sulfone when compared to WT.

Discussion

The introduction of δ-zein gene into C. utilis may lead to significant changes in the metabolic substrates and metabolic pathways, but does not weaken the activity of the strain. Our study provides new insights into the transcriptomic and metabolic characteristics of the genetically engineered C. utilis strain harboring δ-zein gene, which has the potential to advance the utilization of C. utilis as an efficient protein feed in agricultural applications.

Candida utilis and Stenotrophomonas maltophilia causing nosocomial meningitis following a neurosurgical procedure: A rare co-infection

Candida utilis and Stenotrophomonas maltophilia co-infections connected to meningitis are uncommon. We describe a patient who developed C. utilis and S. maltophilia after undergoing neurosurgery and received effective nosocomial meningitis treatment. Multiple neurosurgeries were required for a 16-year-old girl due to complications. For probable nosocomial meningitis, she was treated with cefepime with vancomycin. Meropenem and liposomal amphotericin B were prescribed after her seizure and positive CSF culture for Candida utilis. Consequently, S. maltophilia was discovered in the CSF, and ceftazidime and trimethoprim-sulfamethoxazole were prescribed. The patient has been hemodynamically stable for the past two months, and consecutive CSF cultures have been negative. To the best of our knowledge, this is the first case of C. utilis and S. maltophilia co-infection that has been successfully handled.

Epidemiological features of nosocomial candidaemia in neonates, infants and children: A multicentre study in Iran

Nosocomial bloodstream candidaemia is a life-threatening fungal infection with high morbidity and mortality, especially among paediatric patients undergoing intensive immunosuppressive therapy. Limited data on the epidemiology of candidaemia and susceptibility profiles are available for Iran. To characterise candidaemia epidemiology, comorbidity risk factors, species distribution, and antifungal susceptibility profiles among paediatric patients in Iran. This observational cross-sectional study enrolled 26 189 patients <18 years old at three reference paediatric hospitals in Mazandaran and Tehran over 2 years. Blood samples from patients with suspected fungal bloodstream infection were analysed using the BACTEC culture system. Fungal isolates were identified using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF) and DNA sequencing. Antifungal susceptibility testing was performed using the Clinical and Laboratory Standards Institute broth microdilution guideline. We observed 109 episodes of nosocomial candidaemia in paediatric patients with or without immunosuppressive therapy. The most common healthcare-associated factor was central vascular catheter use (97%). The all-cause mortality rate was 40%, of which 48% was attributable to candidaemia. While Candida albicans was the most frequent causative agent (49%), emerging and uncommon Candida species were also isolated. Candidaemia mortality by non-albicans Candida species was significantly higher than that by C. albicans (P < .05). All fluconazole-resistant species were non-albicans Candida species. Uncommon Candida species with reduced susceptibility to antifungals are emerging as major agents of nosocomial candidaemia in high-risk paediatric patients in Iran. Appropriate source control, antifungal regimens and improved antifungal stewardship are warranted for managing and decreasing the burden of nosocomial candidaemia.

Candida urinary tract infections in adults

Candiduria is commonly seen in hospitalized patients and most of the patients are asymptomatic, but it may be due to cystitis, pyelonephritis, prostatitis, epididymo-orchitis or disseminated candidiasis. Major risk factors are diabetes mellitus, indwelling urinary catheters, use of broad-spectrum antibiotics, urinary obstruction, and admission to intensive care units. Candida urinary tract infections can be caused by hematogenous spread following candidemia, or retrograde route via the urethra. The presence of Candida species in urine in asymptomatic patients does not warrant antifungal therapy except neutropenic patients, very low-birth-weight infants and patients undergoing urologic procedures. Fluconazole is the treatment of choice for symptomatic infections, it achieves high urinary levels. The other azole antifungals and echinocandins do not reach sufficient urine levels. Amphotericin B deoxycholate is the alternative antifungal agent if fluconazole can not be used because of resistance, allergy or failure.