The epidemiology of Candida species isolated from urinary tract infections

Candida spp. are members of a genus, including closely related fungal species that cause a variety of infections. Objectives: The aim of this study was the isolation of various Candida species from vulvovaginitis and urethra of patients in Neyshabur, Northeast Iran from 2013 to 2015. Methods: This descriptive-analytical and cross-sectional study was performed to identify Candida spp. causing vulvovaginitis and Urinary Tract Infection (UTI) at a referral laboratory in Neyshabur district, Khorasan Razavi Province. A total of 451 vaginal and midstream urine samples were collected. Ten micro-liters of each specimen was cultured on CHROM agar plates and then incubated at 37°C for 24 to 48 hours, aerobically. Candida species were identified based on colony morphology, germ tube production and micro-morphology on corn meal agar including 1% Tween 80. Results: The mean age of the patients was 34.7_16.3. Candida albicans was the predominant species isolated. Moreover, age groups of 21 to 30 and 0 to 1 years were the most and the least infected individuals. Moreover, Candida spp. were significantly morecommon in females compared to males (P value 103. Conclusions: In this study, C. albicans was the most common species isolated from patients with vulvovaginitis and UTI, and significantly more common amongst females compared to males. The prevalence of candida spp. had significantly declined from 2013 to 2015. Moreover, the candida spp. counts were mostly higher than 103cfu/mL

IL-1 receptor antagonist ameliorates inflammasome-dependent inflammation in murine and human cystic fibrosis

Dysregulated inflammasome activation contributes to respiratory infections and pathologic airway inflammation. Through basic and translational approaches involving murine models and human genetic epidemiology, we show here the importance of the different inflammasomes in regulating inflammatory responses in mice and humans with cystic fibrosis (CF), a life-threatening disorder of the lungs and digestive system. While both contributing to pathogen clearance, NLRP3 more than NLRC4 contributes to deleterious inflammatory responses in CF and correlates with defective NLRC4-dependent IL-1Ra production. Disease susceptibility in mice and microbial colonization in humans occurrs in conditions of genetic deficiency of NLRC4 or IL-1Ra and can be rescued by administration of the recombinant IL-1Ra, anakinra. These results indicate that pathogenic NLRP3 activity in CF could be negatively regulated by IL-1Ra and provide a proof-of-concept evidence that inflammasomes are potential targets to limit the pathological consequences of microbial colonization in CF

Contribution of CgPDR1-Regulated Genes in Enhanced Virulence of Azole-Resistant Candida glabrata

In Candida glabrata, the transcription factor CgPdr1 is involved in resistance to azole antifungals via upregulation of ATP binding cassette (ABC)-transporter genes including at least CgCDR1, CgCDR2 and CgSNQ2. A high diversity of GOF (gain-of-function) mutations in CgPDR1 exists for the upregulation of ABC-transporters. These mutations enhance C. glabrata virulence in animal models, thus indicating that CgPDR1 might regulate the expression of yet unidentified virulence factors. We hypothesized that CgPdr1-dependent virulence factor(s) should be commonly regulated by all GOF mutations in CgPDR1. As deduced from transcript profiling with microarrays, a high number of genes (up to 385) were differentially regulated by a selected number (7) of GOF mutations expressed in the same genetic background. Surprisingly, the transcriptional profiles resulting from expression of GOF mutations showed minimal overlap in co-regulated genes. Only two genes, CgCDR1 and PUP1 (for PDR1 upregulated and encoding a mitochondrial protein), were commonly upregulated by all tested GOFs. While both genes mediated azole resistance, although to different extents, their deletions in an azole-resistant isolate led to a reduction of virulence and decreased tissue burden as compared to clinical parents. As expected from their role in C. glabrata virulence, the two genes were expressed as well in vitro and in vivo. The individual overexpression of these two genes in a CgPDR1-independent manner could partially restore phenotypes obtained in clinical isolates. These data therefore demonstrate that at least these two CgPDR1-dependent and -upregulated genes contribute to the enhanced virulence of C. glabrata that acquired azole resistance

A Role for the Unfolded Protein Response (UPR) in Virulence and Antifungal Susceptibility in Aspergillus fumigatus

Filamentous fungi rely heavily on the secretory pathway, both for the delivery of cell wall components to the hyphal tip and the production and secretion of extracellular hydrolytic enzymes needed to support growth on polymeric substrates. Increased demand on the secretory system exerts stress on the endoplasmic reticulum (ER), which is countered by the activation of a coordinated stress response pathway termed the unfolded protein response (UPR). To determine the contribution of the UPR to the growth and virulence of the filamentous fungal pathogen Aspergillus fumigatus, we disrupted the hacA gene, encoding the major transcriptional regulator of the UPR. The ΔhacA mutant was unable to activate the UPR in response to ER stress and was hypersensitive to agents that disrupt ER homeostasis or the cell wall. Failure to induce the UPR did not affect radial growth on rich medium at 37°C, but cell wall integrity was disrupted at 45°C, resulting in a dramatic loss in viability. The ΔhacA mutant displayed a reduced capacity for protease secretion and was growth-impaired when challenged to assimilate nutrients from complex substrates. In addition, the ΔhacA mutant exhibited increased susceptibility to current antifungal agents that disrupt the membrane or cell wall and had attenuated virulence in multiple mouse models of invasive aspergillosis. These results demonstrate the importance of ER homeostasis to the growth and virulence of A. fumigatus and suggest that targeting the UPR, either alone or in combination with other antifungal drugs, would be an effective antifungal strategy

Rare fungal pathogens – upcoming guidelines: hyalohyphomycetes

On behalf of the ECMM and EFISG Study group Hyalohyphomycosis is a heterogeneous group of infections characterized by the presence of hyaline hyphae in tissues. The infecting fungi, belonging to several genera (Fusarium, Scedosporium, Acremonium, Scopulariopsis, Purpureocillium and Paecilomyces), are ubiquitous in the environment and commonly isolated from soil. Histopathological findings of septate, branching, hyaline hyphae are similar to those of aspergillosis. Therefore a definitive diagnosis requires isolation of the pathogens from infected sites. Blood cultures are often positive in case of invasive infection. Due to the variable susceptibility of these fungi to antifungal agents identification of the fungus grown on culture is important. As species identification based on morphological characteristics is difficult, molecular identification methods are often required. Antifungal susceptibility testing is recommended under certain circumstances to guide antifungal therapy, even if the clinical breakpoints have yet to be defined. Several inhouse molecular diagnostic tests have been developed, they appear promising but should be used only to supplement conventional laboratory tests. Given the lack of clinical trials, the scarcity of data and the potential publication bias, no solid recommendations for the management of these mycoses can be provided. Voriconazole represents the first line treatment of infections due to Fusarium spp and Scedosporium spp. Therapy should include surgical debridement where possible

Effects of amphotericin B on Aspergillus flavus clinical isolates with variable susceptibilities to the polyene in an experimental model of systemic aspergillosis

OBJECTIVES: The aim of the present study was to evaluate the effects of amphotericin B (AMB) on clinical isolates of Aspergillus flavus. METHODS: MICs of both standard AMB and liposomal AMB (L-AMB) were determined using a broth dilution method for seven isolates of A. flavus. AMB MICs were also determined using the Etest. The activity of the polyene was then investigated in a murine model of systemic aspergillosis in which animals were infected intravenously, treated intravenously with several doses of the polyene (1-10 mg/kg/day) and observed for survival. RESULTS: Broth dilution AMB, broth dilution L-AMB and Etest AMB MICs ranged from 0.5 to 2.0 mg/L, 0.06 to >16 mg/L and 1.0 to >32 mg/L, respectively. There were two isolates for which all doses were effective at prolonging the survival. Their AMB MICs were 641.0 mg/L, regardless of the method/drug formulation utilized for testing. There were four isolates for which no regimen was effective. Their broth dilution AMB, broth dilution L-AMB and Etest AMB MICs ranged from 1.0 to 2.0 mg/L, 0.06 to >16 mg/L and 2.0 to >32 mg/L, respectively. There was one isolate for which only L-AMB given at 10 mg/kg/day was effective; broth dilution MICs of AMB and L-AMB were 0.5 mg/L, while the Etest MIC of AMB was 2.0 mg/L. CONCLUSIONS: Our data indicate that not all isolates of A. flavus should be considered resistant to AMB. The Etest represented the in vitro method that best correlated with the experimental infection. Finally, a clinical isolate showing an MIC 652.0 mg/L may be reasonably considered resistant in vivo to any dose/formulation of the polyene