OBJECTIVE: To evaluate the synergy of the Burkholderia signaling molecule cis-2-dodecenoic acid (BDSF) and fluconazole (FLU) or itraconazole (ITRA) against two azole-resistant C. albicans clinical isolates in vitro and in vivo. METHODS: Minimum inhibitory concentrations (MICs) of antibiotics against two azole-resistant C. albicans were measured by the checkerboard technique, E-test, and time-kill assay. In vivo antifungal synergy testing was performed on mice. Analysis of the relative gene expression levels of the strains was conducted by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). RESULTS: BDSF showed highly synergistic effects in combination with FLU or ITRA with a fractional inhibitory concentration index of ⪕ 0.08. BDSF was not cytotoxic to normal human foreskin fibroblast cells at concentrations of up to 300 μg/mL. The qRT-PCR results showed that the combination of BDSF and FLU/ITRA significantly inhibits the expression of the efflux pump genes CDR1 and MDR1 via suppression of the transcription factors TAC1 and MRR1, respectively, when compared with FLU or ITRA alone. No dramatic difference in the mRNA expression levels of ERG1, ERG11, and UPC2 was found, which indicates that the drug combinations do not significantly interfere with UPC2-mediated ergosterol levels. In vivo experiments revealed that combination therapy can be an effective therapeutic approach to treat candidiasis. CONCLUSION The synergistic effects of BDSF and azoles may be useful as an alternative approach to control azole-resistant Candida infections.
Antifungal Agents ; pharmacology ; Burkholderia cenocepacia ; chemistry ; Candida albicans ; drug effects ; physiology ; Candidiasis ; drug therapy ; Drug Resistance, Fungal ; Fatty Acids, Monounsaturated ; adverse effects ; Fluconazole ; pharmacology ; Humans ; Microbial Sensitivity Tests ; Triazoles ; metabolism

Antifungal drug resistance is a significant clinical problem, and antifungal agents that can evade resistance are urgently needed. In infective niches, resistant organisms often co-existed with sensitive ones, or a subpopulation of antibiotic-susceptible organisms may evolve into resistant ones during antibiotic treatment and eventually dominate the whole population. In this study, we established a co-culture assay in which an azole-resistant Candida albicans strain was mixed with a susceptible strain labeled with green fluorescent protein to mimic in vivo conditions and screen for antifungal drugs. Fluconazole was used as a positive control to verify the validity of this co-culture assay. Five natural molecules exhibited antifungal activity against both susceptible and resistant C. albicans. Two of these compounds, retigeric acid B (RAB) and riccardin D (RD), preferentially inhibited C. albicans strains in which the efflux pump MDR1 was activated. This selectivity was attributed to greater intracellular accumulation of the drugs in the resistant strains. Changes in sterol and lipid compositions were observed in the resistant strains compared to the susceptible strain, and might increase cell permeability to RAB and RD. In addition, RAB and RD interfered with the sterol pathway, further aggregating the decrease in ergosterol in the sterol synthesis pathway in the MDR1-activated strains. Our findings here provide an alternative for combating resistant pathogenic fungi.
ATP-Binding Cassette Transporters ; genetics ; metabolism ; Antifungal Agents ; chemistry ; metabolism ; pharmacology ; Azoles ; pharmacology ; Biosynthetic Pathways ; drug effects ; genetics ; Candida albicans ; chemistry ; drug effects ; metabolism ; Cell Membrane ; chemistry ; metabolism ; Coculture Techniques ; Drug Resistance, Fungal ; drug effects ; Ergosterol ; metabolism ; Fungal Proteins ; genetics ; metabolism ; Lipids ; chemistry ; Molecular Structure ; Permeability ; Phenyl Ethers ; chemistry ; metabolism ; pharmacology ; Sterols ; chemistry ; metabolism ; Stilbenes ; chemistry ; metabolism ; pharmacology ; Triterpenes ; chemistry ; metabolism ; pharmacology

Cross Infection ; microbiology ; therapy ; Drug Resistance, Multiple, Fungal ; Fungi ; classification ; drug effects ; isolation & purification ; Humans ; Mycoses ; microbiology ; therapy ; Patient Care Management ; methods ; Singapore

Adult ; Aged ; Antifungal Agents ; administration & dosage ; adverse effects ; classification ; Candida ; drug effects ; isolation & purification ; Carcinoma ; pathology ; therapy ; Cross Infection ; microbiology ; therapy ; Drug Resistance, Multiple, Fungal ; Female ; Fractures, Bone ; surgery ; Humans ; Male ; Middle Aged ; Mycoses ; microbiology ; therapy ; Patient Care Management ; methods ; Pulmonary Disease, Chronic Obstructive ; complications ; therapy ; Surgical Wound Infection ; microbiology ; therapy ; Symptom Flare Up ; Treatment Outcome

BACKGROUNDDuring the past decades, the incidence of invasive aspergillosis (IA) caused by Aspergillus fumigatus has increased dramatically. The aims of this study were to investigate the susceptibility of clinical isolates of A. fumigatus to triazole and the underlying cyp51A mutations in triazole-resistant A. fumigatus.

METHODSA total of 126 A. fumigatus clinical isolates from 126 patients with proven or probable IA were obtained from four large tertiary hospitals in Nanjing, China, between August 2012 and July 2015. The determination of minimal inhibitory concentrations (MICs) for itraconazole, voriconazole, and posaconazole was performed by broth microdilution according to the European Committee on Antimicrobial Susceptibility Testing reference method.

RESULTSA total of 4 A. fumigatus isolates (3.17%) were confirmed to be itraconazole resistant, with MICs of ≥8 mg/L, and one isolate (0.8%) was confirmed to be voriconazole resistant and posaconazole resistant, with MICs of 4 mg/L and 0.5 mg/L, respectively. We found that two of the 4 isolates of triazole-resistant A. fumigatus had the L98H amino acid substitution in combination with a 34-base pair tandem repeat in the promoter region, one isolate had an M220I mutation, and another itraconazole-resistant isolate did not have a substitution in the cyp51A gene.

CONCLUSIONSThis study shows that triazole-resistant A. fumigatus clinical isolates are present in Nanjing, China, which is a new challenge to the clinical management of IA.

Antifungal Agents ; pharmacology ; Aspergillus fumigatus ; drug effects ; genetics ; China ; Drug Resistance, Fungal ; Itraconazole ; pharmacology ; Microbial Sensitivity Tests ; Promoter Regions, Genetic ; genetics ; Tandem Repeat Sequences ; genetics ; Triazoles ; pharmacology ; Voriconazole ; pharmacology

BACKGROUNDVulvovaginal candidiasis (VVC) was a common infection associated with lifelong harassment of woman's social and sexual life. The purpose of this study was to describe the species distribution and in vitroCandidaCandida spp.) isolated from patients with VVC over 8 years.

METHODSSpecies which isolated from patients with VVC in Peking University First Hospital were identified using chromogenic culture media. Susceptibility to common antifungal agents was determined using agar diffusion method based on CLSI M44-A2 document. SPSS software (version 14.0, Inc., Chicago, IL, USA) was used for statistical analysis, involving statistical description and Chi-square test.

RESULTSThe most common strains were Candida (C.) albicans, 80.5% (n = 1775) followed by C. glabrata, 18.1% (n = 400). Nystatin exhibited excellent activity against all species (<4% resistant [R]). Resistance to azole drugs varied among different species. C. albicans: clotrimazole (3.1% R) < fluconazole (16.6% R) < itraconazole (51.5% R) < miconazole (54.0% R); C. glabrata: miconazole (25.6% R) < clotrimazole (50.5% R) < itraconazole (61.9% R) < fluconazole (73.3% R); Candida krusei: clotrimazole (0 R) < fluconazole (57.7% R) < miconazole (73.1% R) < itraconazole (83.3% R). The susceptibility of fluconazole was noticeably decreasing among all species in the study period.

CONCLUSIONSNystatin was the optimal choice for the treatment of VVC at present. The species distribution and in vitroCandida spp. isolated from patients with VVC had changed over time.

Antifungal Agents ; pharmacology ; Candida ; drug effects ; pathogenicity ; Candidiasis, Vulvovaginal ; microbiology ; China ; Clotrimazole ; pharmacology ; Drug Resistance, Fungal ; Female ; Fluconazole ; pharmacology ; Humans ; Itraconazole ; pharmacology ; Miconazole ; pharmacology ; Microbial Sensitivity Tests

OBJECTIVETo perform a transcriptomics study in differential genes after Xianglian External Lotion (XEL) induced the recovery of drug-resistant Candida albicans strains sensitive to Fluconazole.

METHODSBroth microdilution antifungal susceptibility test was used to detect minimal inhibitory concentration (MIC) of drug-resistant Candida albicans strains induced by XEL. Transcriptome sequencing (RNA-Seq) was used to determine and compare the transcription of primary drug-resistant Candida aIbicans strains and sensitive strains induced by XEL. High expressed genes and signaling pathways strains were analyzed by gene ontology (GO) method.

RESULTSXEL could induce drug-resistant strains of the 6th generations to recover sensitivity. Transcriptome sequencing showed that, as compared with primary drug-resistant strains, there were 165 genes with up-regulated RPKM index and 144 genes with down-regulated RPKM index after XEL induction. GO analyses found that all genes were mainly classified as GO:0015903 (fluconazole transport).

CONCLUSIONSXEL could induce the recovery of drug-resistant Candida albicans strains sensitive to Fluconazole. By analyzing transcriptomes, authors speculated that XEL could recover strain sensitivity to fluconazole by opening fluconazole transport pathway.

Antifungal Agents ; pharmacology ; therapeutic use ; Candida ; Candida albicans ; drug effects ; genetics ; Candidiasis ; drug therapy ; Drug Resistance, Fungal ; drug effects ; genetics ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Fluconazole ; pharmacology ; Microbial Sensitivity Tests

OBJECTIVETo investigate the effects of ethyl acetate extract of Huanglian Jiedu decoction (EAHD) , alone and in combination with fluconazole (FLZ) on FLZ-resistant Candida albicans.

METHODThe minimum inhibitory concentrations (MIC) and sessile MIC80 (SMIC80) of EAHD and FLZ to FLZ-resistant C. albicans were determined by CLSI M27-A3 microdilution method, and the synergy of EAHD combined with FLZ were examined by the checkerboard microdilution assay. Agar plate-method was adopted to observe the rate of antifungal activity according to time-kill curve. HPLC and qRT-PCR were utilized to evaluate the changes of ergosterol content and expressions of related genes, respectively.

RESULTMICs of EAHD ranged from 156 to 1,250 mg · L(-1), those of FLZ from 256 to above 2,048 mg · L(-1) with FICI approximate 0.066 in combination; SMIC80 of EAHD were higher than 1,250 mg · L(-1), SMIC80 of FLZ were higher than 512 mg · L(-1) and up to above 2,048 mg · L(-1). Combination group also showed synergy effect except one group showing addition effect. The results of T-K experiment also confirmed obviously fungicidal effect when treated for 12 h. When compared with control groups, the ergosterol was reduced 85% and 50% in the treatments of combination and EAHD alone by HPLC, respective- ly. The expressions of ERG1, ERG2, ERG6, ERG7 and ERG11 were upregulated, and ACS1, ACS2, MET6 were downregulated when exposed to FLZ. The expressions of the above genes were downregulated by treatment of EAHD. The expressions of ERG2, ERG6, ERG11 were upregulated, while ERG1, ERG7, ACS1, ACS2, MET6 were downregulated in combination group.

CONCLUSIONThe combination of EAHD and FLZ exhibited synergy against FLZ-resistant C. albicans through decreasing the synthesis of ergosterol, and resulting in the breakage of cell membrane.

Antifungal Agents ; pharmacology ; Candida albicans ; drug effects ; growth & development ; metabolism ; Drug Resistance, Fungal ; drug effects ; Drug Synergism ; Drugs, Chinese Herbal ; pharmacology ; Ergosterol ; biosynthesis ; Fluconazole ; pharmacology ; Microbial Sensitivity Tests

Due to substantial morbidity and high complications, diabetes mellitus is considered as the third "killer" in the world. Medicinal fungal polysaccharides, as water-soluble macromolecular substances with low toxicity, exhibit diversified pharmacological actions such as immune regulation, anti-tumor, antivirus, antioxidant, anti-aging, hypoglycemic effect and improving liver and kidney function. In recent year, a number of investigators reported medicinal fungal polysaccharides showed good anti-diabetes and hypoglycemic activity, and their acting mechanisms involved in glycometabolism and β cell function, e. g. promoting glycogen synthesis, promoting glycolysis, inhibiting the activity of α-glucosidase, promoting insulin secretion, increasing insulin sensitivity, enhancing antioxidation. Therefore, the hypoglycemic activity and its mechanisms of action of medicinal fungal polysaccharides showed characteristics of multiple effects, multi-target, and multi-pathway regulation. These finding suggest that medicinal fungal polysaccharides are a promising source for the development of discovery of anti-diabetic agent.
Animals ; Carbohydrate Metabolism ; drug effects ; Fungal Polysaccharides ; pharmacology ; Humans ; Hypoglycemic Agents ; pharmacology ; Insulin Resistance ; Insulin-Secreting Cells ; drug effects ; Oxidative Stress ; drug effects

BACKGROUNDAccording to data from the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) 2010, Candida tropicalis (C. tropicalis) is the third most common pathogen causing invasive candidiasis. Moreover, the majority of fluconazole-resistant C. tropicalis isolates were from a single hospital. Therefore, a molecular epidemiological survey is necessary to investigate the genetic relatedness of C. tropicalis isolates in China.

METHODSIn this study, 48 C. tropicalis isolates causing invasive fungal infections from four tertiary hospitals in China were studied. All the isolates were identified by sequencing the internal transcribed spacer region. Antifungal susceptibility to triazoles, amphotericin B, and caspofungin was determined by the Clinical and Laboratory Standards Institute standard broth microdilution method. Multilocus sequence typing (MLST) was performed, and phylogenetic analysis was further performed by the eBURST and maximum parsimony (MP) methods to characterize the genetic relatedness of isolates.

RESULTSMLST discriminated 40 diploid sequence types (DSTs) among 48 isolates, including 36 novel DSTs, and the XYR1 gene showed the highest discriminatory power. The DSTs obtained from this study were compared with those of previously reported C. tropicalis isolates, and there was poor type alignment with regional strains. Nine groups and 11 singletons were identified by eBURST, whereas two groups and 10 subgroups were clustered by MP analysis. Generally, there were no obvious correlations between clonal clusters generated and the specimen source or hospital origin. Seven fluconazole-resistant isolates were confirmed and assigned to three distinguishable branches.

CONCLUSIONSThe results suggested diverse origins of invasive C. tropicalis isolates in China. Although most invasive C. tropicalis strains in the mainland of China were clustered with previously characterized Asian isolates, major C. tropicalis clusters identified in this study were genetically distinct from those of other geographic regions.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antifungal Agents ; therapeutic use ; Candida tropicalis ; drug effects ; pathogenicity ; Candidiasis ; drug therapy ; China ; Drug Resistance, Fungal ; genetics ; Female ; Humans ; Male ; Middle Aged ; Multilocus Sequence Typing ; methods ; Phylogeny ; Young Adult