Serum interleukin-6 levels in murine models of Candida albicans infection

Risk factors associated with short-term mortality in patients with candidemia and the predictive value of serum cytokine level

BACKGROUND

Some pro-inflammatory and anti-inflammatory cytokines were significantly elevated in patients with candidemia patients, but no studies have included these cytokines in the analysis of risk factors for mortality of candidemia. This study aims to analyze the risk factors of short-term mortality of candidemia and the predictive value of serum cytokines.

METHODS

We retrospectively analyzed and compared the clinical features, risk factors and cytokine interleukin (IL)-6, interferon-γ (IFN-γ), IL-10 and IL-17 between survival group and death group in 53 patients with candidemia. Receiver operating of the characteristic curve (ROC) analysis was performed and figured up area under the curve (AUC), sensitivity and specificity values to assess the predictive power of independent factors associated with mortality.

RESULTS

The overall in-hospital mortality rate of candidemia was 62.3 % (33/53), and the 30-day mortality rate was 52.8 % (28/53). The C. albicans accounting for 17.0 % (9/53), and the non-albicans Candida was 83.0 % (44/53). Serum IL-6 (p = 0.041, HR = 1.009), IFN-γ (p = 0.013, HR = 1.007, 95 %), procalcitonin (PCT) (p = 0.010, HR = 0.899) and Candida score (p = 0.033, HR = 1.659) were independent risk factors, while Initiation of targeted antifungal therapy within 48 h of positive blood cultures (BC) (P = 0.015, HR = 0.266) was a protective factor. The AUC of ROC for Candida score, serum IL-6, PCT, IFN-γ, and Initiation of targeted antifungal therapy within 48 h of positive BC showed 0.933, 0.841, 0.801, 0.732, 0.714, respectively. IL-6 and IFN-γ comprised good performing model for predicting 30-day and 90-day mortality, while IL-6 and IL-10 were the best combinations for predicting 90-day mortality.

CONCLUSIONS

Serum IL-6, IFN-γ, PCT, and Candida score can predict short-term mortality risk in patients with candidemia, while prompt and targeted antifungal treatment may reduce mortality. IL-6 could serve as a possible biomarker for predicting short-term mortality of candidemia and its combination with IL-10 or IFN-γ may further improve the predictive value.

Nanoformulation of a novel potent ebselen analog for treatment of vulvovaginal candidiasis

Background: Vulvovaginal candidiasis is primarily caused by Candida albicans (C. albicans). Here, a novel organoselenium compound (G20) was synthesized and evaluated for anti-Candida activity. Methods: Growth-inhibition studies and medium acidification assays to assess the inhibition of the yeast plasma membrane H+-ATPase (Pma1p) were carried out in vitro using G20. A self-nanoemulsifying formulation (SNEP) of G20 was prepared and evaluated for antimycotic activity in a mouse model. Results: G20 inhibited the growth of C. albicans through a mechanism that, at least in part, involves the inhibition of Pma1p. The G20-SNEP formulation significantly reduced vaginal colonization and vaginal inflammation relative to yeast-infected but untreated control mice. Conclusion: G20-SNEP exhibits potent antimycotic activity in a mouse model of vulvovaginal candidiasis.

Tocilizumab Induces IL-10-Mediated Immune Tolerance in Invasive Candidiasis

The existence of a hyperinflammatory state has been observed in patients with invasive fungal infections (IFI). It is being postulated whether morbidity from IFI may, in part, be a consequence of an unnecessarily prolonged or exaggerated proinflammatory immune response including interleukin 6 (IL-6) post-infection, in a host with dysregulated or compromised immunity. This, in turn, induces collateral host injury at the tissue and organ level, leading to adverse outcomes. Tocilizumab has become widely used as an immunomodulator in the treatment of inflammatory conditions. Here, we evaluated the use of tocilizumab to curb post-infective inflammatory flare in the setting of an in-vivo mouse model for invasive candidiasis. Following Candida infection, the tocilizumab-treated mice showed improved short-term survival compared with the saline-treated control mice. There was a reduced inflammatory response mounted by the host, coupled with reduced IL-6 but increased IL-10 levels. TNF-α and IFN-γ responses were not affected. Tocilizumab facilitated immune tolerance by selectively inducing IL-10, producing CD8α+ conventional dendritic cells (DCs) and peripheral T-regulatory cells, over CD11b+ conventional DCs and plasmacytoid DCs. We demonstrate here the sequelae from immunomodulatory manipulation and the basis whereby the use of monoclonal antibodies may be further explored in IFI.

The effects of secreted aspartyl proteinase inhibitor ritonavir on azoles-resistant strains of Candida albicans as well as regulatory role of SAP2 and ERG11

BACKGROUND

Candida albicans, the main human fungal pathogen, can cause fungal infection and seriously affect people's health and life. This study aimed to investigate the effects of ritonavir (RIT) on C. albicans and the correlation between SAP2 as well as ERG11 and drug resistance.

RESULTS

Secreted aspartyl proteinases (Saps) activities and pathogenicity of C. albicans with different drug resistance were measured. M27-A4 broth microdilution method was used to analyze the drug sensitivity of RIT combined with fluconazole (FCA) on C. albicans. After that, SAP2 and ERG11 mutations were examined by polymerase chain reaction (PCR) and sequencing, and quantitative real-time PCR was utilized to determine the expression of the two genes. By analyzing pz values, the Saps activity of cross-resistant strains was the highest, followed by voriconazole (VRC)-resistant strains, FCA-resistant strains, itraconazole (ITR)-resistant strains, and sensitive strains. The pathogenicity of C. albicans in descending order was as follows: cross-resistant strains, VRC-resistant strains, ITR-resistant strains, FCA-resistant strains, and sensitive strains. With the increase of RIT concentrations, the Saps activity was gradually inhibited. Drug sensitivity results showed that there was no synergistic effect between RIT and FCA. Additionally, no gene mutation sites were found in SAP2 sequencing, and 17 synonymous mutations and 6 missense mutations occurred in ERG11 sequencing. Finally, the expression of SAP2 and ERG11 was significantly higher in the resistant strains compared with the sensitive strains, and there was a positive liner correlation between SAP2 and ERG11 messenger RNA expression (r = .6655, p < .001).

CONCLUSION

These findings may help to improve our understanding of azole-resistant mechanisms of C. albicans and provide a novel direction for clinical therapeutics of C. albicans infection.

New insight of red seaweed derived Callophycin A as an alternative strategy to treat drug resistance vaginal candidiasis

Marine natural products are recognised as one among the major contributors of several important biological functions. The arguments has made to utilization of natural products against different kinds of infectious diseases. In the present study, Callophycin A was successfully prepared and its anti-candidal activity was evaluated through in-vitro and in-vivo methods. The in-vitro results revealed that, Callophycin A significantly inhibits the azole resistant and sensitive C. albicans. Further, in-vivo animal experiments have shown the effective reduction in CFU of C. albicans from its beginning day of the treatment as compared to the disease control group. At the end of Callophycin A administration, there was a decrease in inflammatory response and immune molecules such as IL-6, IL-12, IL-17, IL-22, TNF-α, macrophages, CD4 and CD8 cells were observed. Whereas the animals in the disease control group expressed all the parameters with the elevated level as compared to the control group. There are no hematological abnormalities such as neutropenia, lymphocytosis and eosinophilia was observed in any animal groups except the disease control group. Finally, the evidence based prediction of anti-candidal efficacious of Callophycin A was demonstrated.

Diagnostic efficacy of serum cytokines and chemokines in patients with candidemia and bacteremia

BACKGROUND

The role of serum cytokines/chemokines in differential diagnosis between fungal infections and bacterial infections have not been fully understood. This study aims to measure the serum levels of cytokines/chemokines in cases of candidemia and to compare them with those observed in cases of bacteremia.

MATERIAL AND METHODS

Patients with febrile episodes and were identified as bloodstream infections through blood culture were enrolled, while healthy people were included as control group. Fourteen serum cytokine and chemokine levels were detected with multiplex platform. ROC analysis was performed and an area under the curve (AUC), sensitivity and specificity values were calculated to determine the efficacy of various cytokines and chemokines for candidemia and bacteremia. Binary logistic regression was performed to further explore the combination mode of cytokines and chemokines, which could increase the diagnostic efficiency.

RESULTS

We included 40 patients with an episode of microbiologically proven fungal infection, 175 patients with bacteremia (85 with Gram-positive bacteremia and 90 with Gram-negative bacteremia) and another 30 healthy controls. Routine laboratory parameters including CRP and PCT were not statistically significant between candidemia group and bacteremia group (both gram-positive and gram-negative). There were significantly higher levels of IFN-γ, TNF-α, IL-10 and lower levels of IL-3, IL-4 in candidemia group, compared with gram-positive and gram-negative bacteremia groups. G-CSF was significantly lower and MIP-1β was higher in candidemia group, when compared with gram-negative bacteremia group. While IL-6, IL-8 and IL-17 were all significantly higher in candidemia group, when compared with gram-positive bacteremia group. Combination of IFN-γ and IL-17 could improve the diagnostic efficiency between candidemia and gram-positive bacteremia, with the AUROC of 0.873 (95% CI: 0.767-0.929). While combination of G-CSF and MIP-1β improved the diagnostic efficiency between candidemia and gram-negative bacteremia, with the AUROC of 0.896 (95% CI: 0.792-0.939).

CONCLUSION

Our study demonstrates that serum cytokines and chemokines including IFN-γ, MIP-1β, IL-17 and G-CSF could be considered as diagnostic markers to distinguish between candidemia and bacteremia. Combination of these biomarkers might improve the diagnostic efficiency of candidemia when compared with bacteremia.

Diagnostic efficacy of serum cytokines and chemokines in fungal bloodstream infection in febrile patients

BACKGROUND

The role of serum cytokines/chemokines in early diagnosis of fungal infections has not been clearly clarified yet. This study aims to measure the serum levels of cytokines/chemokines in cases of fungemia and to compare them with culture-negative controls.

METHODS

In total, fourteen types of serum cytokines and chemokines from 41 patients with fungemia were compared with 57 patients with negative blood culture results. The cytokine and chemokine levels were detected with multiplex platform. We then performed statistical analysis as a two-tailed P < .05. ROC analysis was performed, and an area under the curve (AUC), and sensitivity and specificity values were calculated to determine the efficacy of various cytokines and chemokines for fungemia. Binary logistic regression was performed to further explore the combination mode of cytokines and chemokines, which could increase the diagnostic efficiency.

RESULTS

C-reactive protein and procalcitonin were significantly higher compared with those in negative control group, while white blood cell, percentage of neutrophil, percentage of lymphocyte, and ratio of neutrophil and lymphocyte did not differentiate between two groups. Serum levels of IFN-γ, TNF-α, MIP-1β, IL-6, IL-8, IL-10, IL-12p70, and IL-17 were significantly higher in patients with fungemia compared with the control group. Combination of MIP-1β and IL-17 could improve the AUC, sensitivity, and specificity for the diagnosis of fungemia.

CONCLUSION

Our study demonstrates that serum cytokines and chemokines including IFN-γ, TNF-α, MIP-1β, IL-6, IL-8, IL-10, IL-12p70, and IL-17 could be considered as diagnostic markers for fungemia. Combination of these biomarkers might improve the diagnostic efficiency of fungemia.

In Vivo Applicability of Neosartorya fischeri Antifungal Protein 2 (NFAP2) in Treatment of Vulvovaginal Candidiasis

As a consequence of emerging numbers of vulvovaginitis cases caused by azole-resistant and biofilm-forming Candida species, fast and efficient treatment of this infection has become challenging. The problem is further exacerbated by the severe side effects of azoles as long-term-use medications in the recurrent form. There is therefore an increasing demand for novel and safely applicable effective antifungal therapeutic strategies. The small, cysteine-rich, and cationic antifungal proteins from filamentous ascomycetes are potential candidates, as they inhibit the growth of several Candida spp. in vitro; however, no information is available about their in vivo antifungal potency against yeasts. In the present study, we investigated the possible therapeutic application of one of their representatives in the treatment of vulvovaginal candidiasis, Neosartorya fischeri antifungal protein 2 (NFAP2). NFAP2 inhibited the growth of a fluconazole (FLC)-resistant Candida albicans strain isolated from a vulvovaginal infection, and it was effective against both planktonic cells and biofilm in vitro We observed that the fungal cell-killing activity of NFAP2 is connected to its pore-forming ability in the cell membrane. NFAP2 did not exert cytotoxic effects on primary human keratinocytes and dermal fibroblasts at the MIC in vitro. In vivo murine vulvovaginitis model experiments showed that NFAP2 significantly decreases the number of FLC-resistant C. albicans cells, and combined application with FLC enhances the efficacy. These results suggest that NFAP2 provides a feasible base for the development of a fundamental new, safely applicable mono- or polytherapeutic topical agent for the treatment of superficial candidiasis.

The in vitro and in vivo efficacy of fluconazole in combination with farnesol against Candida albicans isolates using a murine vulvovaginitis model

Farnesol is a quorum-sensing molecule that inhibits biofilm formation in Candida albicans. Previous in vitro data suggest that, in combination with certain antifungals, farnesol may have an adjuvant anti-biofilm agent. However, the in vivo efficacy of farnesol is very questionable. Therefore, the in vitro and in vivo activity of fluconazole combined with farnesol was evaluated against C. albicans biofilms using fractional inhibitory concentration index (FICI) determination, time-kill experiments and a murine vulvovaginitis model. The median biofilm MICs of fluconazole-sensitive C. albicans isolates ranged between 4 -> 512 mg/L and 150-300 μM for fluconazole and farnesol, respectively. These values were 512 -> 512 mg/L and > 300 μM for fluconazole-resistant clinical isolates. Farnesol decreased the median MICs of fluconazole by 2-64-fold for biofilms. Based on FICI, synergistic interaction was observed only in the case of the sessile SC5314 reference strain (FICIs: 0.16-0.27). In time-kill studies, only the 512 mg/L fluconazole and 512 mg/L fluconazole + 75 μM farnesol reduced biofilm mass significantly at each time point in the case of all isolates. The combination reduced the metabolic activity of biofilms for all isolates in a concentration- and time-dependent manner. Our findings revealed that farnesol alone was not protective in a murine vulvovaginitis model. Farnesol was not beneficial in combination with fluconazole for fluconazole-susceptible isolates, but partially increased fluconazole activity against one fluconazole-resistant isolate, but not the other one.