Candida albicans ; genetics ; pathogenicity ; Extracellular Matrix ; metabolism

Candida albicans is one of the major causes of invasive fungal infections and a serious opportunistic pathogen in immunocompromised individuals. The antimicrobial peptide AMP-17 has prominent anti-Candida activity, and proteomic analysis revealed significant differences in the expression of cell wall (XOG1) and oxidative stress (SRR1) genes upon the action of AMP-17 on C. albicans, suggesting that AMP-17 may exert anti-C. albicans effects by affecting the expression of XOG1 and SRR1 genes. To further investigate whether XOG1 and SRR1 genes were the targets of AMP-17, C. albicans xog1Δ/Δ and srr1Δ/Δ mutants were constructed using the clustered regulatory interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9) system. Phenotypic observations revealed that deletion of two genes had no significant effect on C. albicans growth and biofilm formation, whereas XOG1 gene deletion affected in vitro stress response and mycelium formation of C. albicans. Drug sensitivity assay showed that the MIC₈₀ values of AMP-17 against xog1Δ/Δ and srr1Δ/Δ mutants increased from 8 μg/mL (for the wild type C. albicans SC5314) to 16 μg/mL, while the MIC₈₀ values against srr1Δ/Δ: : srr1 revertants decreased to the level of the wild type SC5314. In addition, the ability of AMP-17 to inhibit biofilm formation of both deletion strains was significantly reduced compared to that of wild type SC5314, indicating that the susceptibility of the deletion mutants to AMP-17 was reduced in both the yeast state and during biofilm formation. These results suggest that XOG1 and SRR1 genes are likely two of the potential targets for AMP-17 to exert anti-C. albicans effects, which may facilitate further exploration of the antibacterial mechanism of novel peptide antifungal drugs.
Humans ; Candida albicans ; Antimicrobial Peptides ; Proteomics ; Peptides/pharmacology* ; Transcription Factors/metabolism* ; Antifungal Agents/pharmacology*

OBJECTIVETo investigate the genotypic profiles of Candida albicans isolates from erosive oral lichen planus (OLP) and nonerosive OLP, and then to compare the results with their virulence attributes.

METHODSA total of 112 isolates from healthy control (26), erosive OLP (62) and nonerosive OLP (24) were screened for genotypic profiles by using the randomly amplified polymorphic DNA (RAPD) assay. In addition, adhesion to buccal epithelial cells assay and phospholipase activity assay were used to evaluate the virulence attributes of these isolates.

RESULTSRAPD analyses with some random primer revealed 4 different genotypes among all isolates, and there was significant difference in the geneotypic constitution between every two groups. Statistically, in healthy group the major type was B and D, however, the major type in erosive OLP was A and C, and the major type in nonerosive OLP was A and D. The isolates with genotype A had the strongest adherence among 4 genotypes. The phospholipase activity of the isolates with genotype A and C were higher than that with genotype B and D.

CONCLUSIONSSome Candida albicans isolates with special genotypic profiles and virulence attributes may contribute to the development and progression of OLP.

Adhesiveness ; Candida albicans ; classification ; enzymology ; physiology ; Genotype ; Humans ; Lichen Planus, Oral ; microbiology ; Phospholipases ; metabolism ; Random Amplified Polymorphic DNA Technique

OBJECTIVETo explore the molecular mechanism of the differences in biofilm formation abilities of Candida albicans isolated from the respiratory tract.

METHODSThe biofilms formed by Candida albicans isolates from the respiratory tract and the standard strain ATCC90028 were examined for bacterial proliferation using XTT reduction assay. The mRNA expression of CPH1, EFG1, ALS3 and HWP1 in the isolates were measured with fluorescent quantitative RT-PCR.

RESULTSXTT reduction assay demonstrated a strong ability of biofilm formation in 8 clinical isolates, and a relatively low biofilm formation ability in 7 clinical isolates and ATCC90028 strain. The strong and weak biofilm formers showed significant differences in ALS3 and HWP1 mRNA expressions (P<0.05) but not in EFG1 or CPH1 mRNA expressions (P>0.05).

CONCLUSIONThe clinical isolates from the respiratory tract have different biofilm formation abilities under regulation by genes other than the transcription factors CPH1 and EFG1.

Biofilms ; Candida albicans ; classification ; genetics ; physiology ; DNA-Binding Proteins ; metabolism ; Exons ; Fungal Proteins ; metabolism ; Humans ; Membrane Glycoproteins ; metabolism ; Phenotype ; Respiratory System ; microbiology ; Transcription Factors ; metabolism

In Candida albicans, adaptation to environmental pH is relevant to its pathogenicity. Calcium signaling pathway involves in many stress responses and often accompany with Ca2+ fluctuation. We constructed CCH1 and MID1 mutant strains and studied their effect on calcium influx and further investigated the regulation by Crz1p transcription factor. We used PCR-directed gene disruption to construct cch1delta/delta and mid1delta/delta null mutant. By using a flow cytometry-based method we monitored the free cytosolic Ca2+ levels under alkaline stress. Moreover, we constructed pPHO89-LacZ plasmids and by beta-Galactosidase assays, we analyzed the changes of LacZ activities after gene disruption. The results showed that alkaline stress induced calcium burst reduced obviously in cch1delta/delta and mid1delta/delta mutant strains, also for LacZ activities, and fully abolished in crz1delta/delta mutant strain. Finally, by realtime PCR, we confirmed the regulation role of Crz1p in CCH1 and MID1 genes but in a calcineurin independent way. Studies on the effect of calcium pathway on response to alkaline stress will provide an important theoretical basis for Candida albicans infection-oriented treatment and new drug targets.
Calcium Channels ; metabolism ; Candida albicans ; genetics ; metabolism ; physiology ; Fungal Proteins ; genetics ; physiology ; Gene Expression Regulation, Fungal ; Hydrogen-Ion Concentration ; Signal Transduction ; Stress, Physiological ; Transcription Factors ; metabolism ; physiology

OBJECTIVETo examine the expression of nucleotide-binding oligomerization domain 1 (NOD1), nuclear factor-kappa B (NF-κB) and human beta-defensins in candidal albicans leukoplakia and to investigate the effect of candida albicans infection on key proteins in NOD1 signaling pathway and the expression of human beta-defensin.

METHODSForty cases of oral leukoplakia samples were collected and stained by hematoxylin-eosin staining, periodic acid-Schiff staining, silver staining and immunohistochemical methods. Nineteen samples were positive with these four methods and judged as candidal albicans leukoplakia, and the other twenty- one samples judged as leukoplakia without candidal albicans infection. Western blotting was used to detect the expressions of NOD1 and NF-κB in these forty samples. In addition, the immunohistochemical method was adopted to investigate the relationship between NOD1, NF-κB, human beta-defensin 1, 2, 3 expressions and candida albicans.

RESULTSThe positive rate of candida albicans in oral leukoplakia was 48% (19/40). The expressions of NOD1 and NF-κB in the candida albicans leukoplakia were lower than that in leukoplakia without candida albicans infection. The mean optical density value of NOD1, NF-κB, human beta-defensin 1, 2, 3 in candidal albicans leukoplakia were 0.25 ± 0.01, 0.30 ± 0.02, 0.35 ± 0.02, 0.42 ± 0.03, 0.36 ± 0.02 respectively, which were significantly lower than that in leukoplakia without candida albicans infection (0.31 ± 0.02, 0.47 ± 0.03, 0.42 ± 0.02, 0.53 ± 0.04, 0.47 ± 0.03) (P < 0.05).

CONCLUSIONSBy inhibiting the NOD1 signaling pathway, candida albicans infection may reduce the expression level of human beta-defensin 1, 2, 3 in oral leukoplakia.

Blotting, Western ; Candida albicans ; Candidiasis ; metabolism ; Humans ; Leukoplakia, Oral ; metabolism ; NF-kappa B ; biosynthesis ; Nod1 Signaling Adaptor Protein ; biosynthesis ; Nucleotides ; Signal Transduction ; beta-Defensins ; biosynthesis

OBJECTIVETo detect the effect of andrographolide on apoptosis of Candida albicans biofilm dispersion cells.

METHODThe morphological changes of apoptotic C. albicans biofilm cells were observed by using Hoechst 33258 staining Fluorescence microscope; changes of mitochondrial membrane potential (MMP) of C. albicans biofilm cells were detected by rhodamine 123 staining flow cytometry; and reactive oxygen species (ROS) was detected by DHR staining flow cytometry.

RESULT1 000, 100 micromol x L(-1) of andrographolide could cause pyknosis and dense staining of C. albicans biofilm cells, 1 000, 100, 10 micromol x L(-1) of andrographolide could decrease MMP and increase ROS of C. albicans biofilm cells.

CONCLUSIONAndrographolide of appropriate concentrations could induce apoptosis of dispersion cells of C. albicans biofilms.

Antifungal Agents ; pharmacology ; Apoptosis ; drug effects ; Biofilms ; Candida albicans ; drug effects ; physiology ; Diterpenes ; pharmacology ; Membrane Potential, Mitochondrial ; drug effects ; Reactive Oxygen Species ; metabolism

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

BACKGROUNDVulvovaginal candidiasis is caused by Candida albicans. The vaginal epithelium, as the first site of the initial stage of infection by pathogens, plays an important role in resisting genital tract infections. Moreover, lactobacilli are predominant members of the vaginal microbiota that help to maintain a normal vaginal microenvironment. Therefore, Lactobacillus crispatus was explored for its capacity to intervene in the immune response of vaginal epithelial cells VK2/E6E7 to C. albicans.

METHODSWe examined the interleukin-2 (IL-2), 4, 6, 8, and 17 produced by VK2/E6E7 cells infected with C. albicans and treated with L. crispatus in vitro. The capacity of L. crispatus to adhere to VK2/E6E7 and inhibit C. albicans growth was also tested by scanning electron microscopy (SEM) and adhesion experiments.

RESULTSCompared with group VK2/E6E7 with C. albicans, when treated with L. crispatus, the adhesion of C. albicans to VK2/E6E7 cells decreased significantly by 52.87 ± 1.22%, 47.03 ± 1.35%, and 42.20 ± 1.55% under competition, exclusion, and displacement conditions, respectively. SEM revealed that the invasion of C. albicans into VK2/E6E7 cells was caused by induced endocytosis and active penetration. L. crispatus could effectively protect the cells from the virulence of hyphae and spores of C. albicans and enhance the local immune function of the VK2/E6E7 cells. The concentrations of IL-2, 6, and 17 were upregulated significantly (P < 0.01) and that of IL-8 were downregulated significantly (P < 0.01) in infected VK2/E6E7 cells treated with L. crispatus. The concentration of IL-4 was similar to that of the group VK2/E6E7 with C. albicans (24.10 ± 0.97 vs. 23.12 ± 0.76 pg/ml, P = 0.221).

CONCLUSIONSL. crispatus can attenuate the virulence of C. albicans, modulate the secretion of cytokines and chemokines, and enhance the immune response of VK2/E6E7 cells in vitro. The vaginal mucosa has a potential function in the local immune responses against pathogens that can be promoted by L. crispatus.

Candida albicans ; pathogenicity ; Cell Line, Tumor ; Epithelial Cells ; immunology ; metabolism ; microbiology ; ultrastructure ; Female ; Humans ; Interleukin-17 ; metabolism ; Interleukin-2 ; metabolism ; Interleukin-4 ; metabolism ; Interleukin-6 ; metabolism ; Interleukin-8 ; metabolism ; Lactobacillus crispatus ; physiology ; Microscopy, Electron, Scanning ; Vagina ; cytology

OBJECTIVETo investigate whether Candida albicans-native phospholipomannan (PLM) induce an inflammation response through Toll-like receptor(TLRé2 in human acute monocytic leukemia cell line (THP-1) cells.

METHODSHuman THP-1 monocytes were challenged with PLM in vitro. The mRNA expressions of TLR2, TLR4, proinflammatory cytokine [interleukin(IL)-6], and chemokine (IL-8) were assayed by real time reverse transcription polymerase chain reaction. The secretions of IL-6 and IL-8 were measured by enzyme-linked immunosorbent assay. The expression of TLR2 was analyzed with Western blot.

RESULTSPLM increased the mRNA expressions and secretions of proinflammatory cytokines (IL-6) and chemokines (IL-8) in THP-1 cells (all P=0.0000). PLM up-regulated the mRNA and protein levels of TLR2 (P=0.0000), whereas the mRNA level of TLR4 was not altered. PLM hydrolyzed with β-D-mannoside manno hydrolase failed to induce gene and protein expressions of TLR2, IL-6, and IL-8. Anti-TLRS-neutralizing antibody blocked the PLM-induced secretions of IL-6 and IL-8 in THP-1 cells (P = 0.0003, P = 0.0010).

CONCLUSIONCanidada albicans-native PLM may contribute to the inflammatory responses during Candida infection in a TLR2-dependent manner.

Candida albicans ; chemistry ; Cells, Cultured ; Glycolipids ; pharmacology ; Humans ; Interleukin-6 ; metabolism ; Interleukin-8 ; metabolism ; Monocytes ; drug effects ; immunology ; metabolism ; Toll-Like Receptor 2 ; metabolism ; Toll-Like Receptor 4 ; metabolism