Antifungal Drugs for Invasive Candida Infections (ICI) in Neonates: Future Perspectives

Invasive Candida Infections in Neonatal Intensive Care Units: Risk Factors and New Insights in Prevention

Invasive Candida infections represent a significant cause of morbidity and mortality in neonatal intensive care units (NICUs), with a particular impact on preterm and low-birth-weight neonates. In addition to prematurity, several predisposing factors for Candida colonization and dissemination during NICU hospitalization have been identified, including prolonged exposure to broad-spectrum antibiotics, central venous catheters, parenteral nutrition, corticosteroids, H2 antagonist administration, and poor adherence to infection control measures. According to the literature, the implementation of antifungal prophylaxis, mainly fluconazole, in high-risk populations has proven to be an effective strategy in reducing the incidence of fungal infections. This review aims to provide an overview of risk factors for invasive Candida infections and current perspectives regarding antifungal prophylaxis use. Recognizing and reducing people's exposure to these modifiable risk factors, in conjunction with the administration of antifungal prophylaxis, has been demonstrated to be an effective method for preventing invasive candidiasis in susceptible neonatal populations.

Helium Cold Atmospheric Plasma Causes Morphological and Biochemical Alterations in Candida albicans Cells

(1) Background: Previous studies reported the promising inhibitory effect of cold atmospheric plasma (CAP) on Candida albicans. However, the exact mechanisms of CAP's action on the fungal cell are still poorly understood. This study aims to elucidate the CAP effect on C. albicans cell wall, by evaluating the alterations on its structure and biochemical composition; (2) Methods: C. albicans cells treated with Helium-CAP were analyzed by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) in order to detect morphological, topographic and biochemical changes in the fungal cell wall. Cells treated with caspofungin were also analyzed for comparative purposes; (3) Results: Expressive morphological and topographic changes, such as increased roughness and shape modification, were observed in the cells after CAP exposure. The alterations detected were similar to those observed after the treatment with caspofungin. The main biochemical changes occurred in polysaccharides content, and an overall decrease in glucans and an increase in chitin synthesis were detected; (4) Conclusions: Helium-CAP caused morphological and topographic alterations in C. albicans cells and affected the cell wall polysaccharide content.

Hepatic abscess due to Candida species in neonates: Case reports in Vietnam

Neonatal hepatic abscess (NHA) is a fatal condition in neonates. NHA can be caused by many organisms including bacteria, parasites, and fungi. Fungal NHA is a rare but troublesome cause in terms of diagnosis and treatment. We present three cases of fungal NHA caused by Candida. In these three cases, different underlying problems associated with NHA had been found.

Risk Factors, Diagnosis, and Treatment of Neonatal Fungal Liver Abscess: A Systematic Review of the Literature

(1) Background: Although invasive fungal infections are a major cause of neonatal morbidity and mortality, data on the incidence and outcomes of localized abscesses in solid organs due to fungal infections are scarce. The aim of this study was to consolidate evidence and enhance our understanding on neonatal liver abscesses due to invasive fungal infections. (2) Methods: An electronic search of the PubMed and Scopus databases was conducted, considering studies that evaluated fungal liver abscesses in the neonatal population. Data on the epidemiology, clinical course, treatment, and outcome of these infections were integrated in our study. (3) Results: Overall, 10 studies were included presenting data on 19 cases of neonatal fungal liver abscesses. Candida spp. were the most common causative pathogens (94.7%). Premature neonates constituted the majority of cases (93%), while umbilical venous catheter placement, broad spectrum antibiotics, and prolonged parenteral nutrition administration were identified as other common predisposing factors. Diagnosis was established primarily by abdominal ultrasonography. Medical therapy with antifungal agents was the mainstay of treatment, with Amphotericin B being the most common agent (47%). Abscess drainage was required in four cases (21%). Eradication of the infection was achieved in the majority of cases (80%). (4) Conclusions: Even though fungal liver abscess is a rare entity in the neonatal population, clinicians should keep it in mind in small, premature infants who fail to respond to conventional treatment for sepsis, particularly if an indwelling catheter is in situ. A high index of suspicion is necessary in order to achieve a timely diagnosis and the initiation of the appropriate treatment.

Successful fluconazole combined with caspofungin treatment of candida bloodstream infection in preterm infant: A case report

RATIONALE

Candida bloodstream infection continues to be a significant cause of mortality in premature infants. Amphotericin B has been recommended as the primary treatment; however, its use is limited due to drug-induced nephrotoxicity and amphotericin B-resistant candidemia.

PATIENT CONCERNS

The gestational age was 29 (+6) weeks, and birth weight was 1760 g.

DIAGNOSIS

The infant was diagnosed with Candida parapsilosis bloodstream infection.

INTERVENTIONS

Fluconazole, 12 mg/kg/day, combined with caspofungin (loading dose 3 mg/kg, at a maintenance dose of 2 mg/kg every 24 h) therapy was administered to premature infant with Candida bloodstream infection. When fluconazole or caspofungin was used to treat Candida bloodstream infection in preterm infants, the blood cultures of the infant remained positive for Candida parapsilosis.

OUTCOMES

All persistent candidemia resolved on fluconazole combined with caspofungin therapy. There were no adverse effects, hepatotoxicity, nephrotoxicity, anemia, or thrombocytopenia.

LESSONS

Fluconazole combined with caspofungin successfully treated Candida bloodstream infection in premature infants at 29 + 6 weeks' gestational age, but large-scale clinical trials are required.

Micafungin injection for the treatment of invasive candidiasis in pediatric patients under 4 months of age

INTRODUCTION

Neonates and young infants with invasive candidiasis are particularly at increased risk of dissemination including hematogenous Candida meningoencephalitis. The echinocandins including micafungin have emerged as a preferred agent in most cases of candidemia and invasive candidiasis but data in pediatric patients under 4 months of age are limited.

AREAS COVERED

In this report, we review the micafungin use in infants younger than 4 months of age. Animal studies as well as clinical data that support its use in neonatal candidiasis are reviewed. In addition, the status of FDA approval and the rationale of micafungin dosing recommendations in infants <4 months are discussed.

EXPERT OPINION

A dose of 4 mg/kg was approved for treatment of candidemia, Candida peritonitis and abscesses excluding meningoencephalitis or ocular involvement in patients younger than 4 months of age. However, because of the risk of central nervous system dissemination as well as the difficulty in establishing this diagnosis, this dose is inadequate to treat ill infants with candidemia. More studies are needed to establish the safety and efficacy of micafungin daily dose of at least 10 mg/kg in infants younger than 4 months of age when hematogenous Candida meningoencephalitis or ocular involvement cannot be excluded.

Exploration of the Antimicrobial Effects of Benzothiazolylthiazolidin-4-One and In Silico Mechanistic Investigation

BACKGROUND

Infectious diseases still affect large populations causing significant morbidity and mortality. Bacterial and fungal infections for centuries were the main factors of death and disability of millions of humans. Despite the progress in the control of infectious diseases, the appearance of resistance of microbes to existing drugs creates the need for the development of new effective antimicrobial agents. In an attempt to improve the antibacterial activity of previously synthesized compounds modifications to their structures were performed.

METHODS

Nineteen thiazolidinone derivatives with 6-Cl, 4-OMe, 6-CN, 6-adamantan, 4-Me, 6-adamantan substituents at benzothiazole ring were synthesized and evaluated against panel of four bacterial strains S. aureus, L. monocytogenes, E. coli and S. typhimirium and three resistant strains MRSA, E. coli and P. aeruginosa in order to improve activity of previously evaluated 6-OCF3-benzothiazole-based thiazolidinones. The evaluation of minimum inhibitory and minimum bactericidal concentration was determined by microdilution method. As reference compounds ampicillin and streptomycin were used.

RESULTS

All compounds showed antibacterial activity with MIC in range of 0.12-0.75 mg/mL and MBC at 0.25->1.00 mg/mL The most active compound among all tested appeared to be compound 18, with MIC at 0.10 mg/mL and MBC at 0.12 mg/mL against P. aeruginosa. as well as against resistant strain P. aeruginosa with MIC at 0.06 mg/mL and MBC at 0.12 mg/mL almost equipotent with streptomycin and better than ampicillin. Docking studies predicted that the inhibition of LD-carboxypeptidase is probably the possible mechanism of antibacterial activity of tested compounds.

CONCLUSION

The best improvement of antibacterial activity after modifications was achieved by replacement of 6-OCF3 substituent in benzothiazole moiety by 6-Cl against S. aureus, MRSA and resistant strain of E. coli by 2.5 folds, while against L. monocytogenes and S. typhimirium from 4 to 5 folds.

8-hydroxyquinoline-5-(N-4-chlorophenyl) sulfonamide and fluconazole combination as a preventive strategy for Candida biofilm in haemodialysis devices

Introduction. The presence of Candida biofilms in medical devices is a concerning and important clinical issue for haemodialysis patients who require constant use of prosthetic fistulae and catheters.Hypothesis/Gap Statement. This prolonged use increases the risk of candidaemia due to biofilm formation. PH151 and clioquinol are 8-hydroxyquinoline derivatives that have been studied by our group and showed interesting anti-Candida activity.Aim. This study evaluated the biofilm formation capacity of Candida species on polytetrafluoroethylene (PTFE) and polyurethane (PUR) and investigated the synergistic effects between the compounds PH151 and clioquinol and fluconazole, amphotericin B and caspofungin against biofilm cells removed from those materials. Further, the synergistic combination was evaluated in terms of preventing biofilm formation on PTFE and PUR discs.Methodology. Susceptibility testing was performed for planktonic and biofilm cells using the broth microdilution method. The checkerboard method and the time-kill assay were used to evaluate the interactions between antifungal agents. Antibiofilm activity on PTFE and PUR materials was assessed to quantify the prevention of biofilm formation.Results. Candida albicans, Candida glabrata and Candida tropicalis showed ability to form biofilms on both materials. By contrast, Candida parapsilosis did not demonstrate this ability. Synergistic interaction was observed when PH151 was combined with fluconazole in 77.8 % of isolates and this treatment was shown to be concentration- and time-dependent. On the other hand, indifferent interactions were predominantly observed with the other combinations. A reduction in biofilm formation on PUR material of more than 50 % was observed when using PH151 combined with fluconazole.Conclusion. PH151 demonstrated potential as a local treatment for use in a combination therapy approach against Candida biofilm formation on haemodialysis devices.

Plant-Derived Substances in the Fight Against Infections Caused by Candida Species

Yeast-like fungi from the Candida genus are predominantly harmless commensals that colonize human skin and mucosal surfaces, but under conditions of impaired host immune system change into dangerous pathogens. The pathogenicity of these fungi is typically accompanied by increased adhesion and formation of complex biofilms, making candidal infections challenging to treat. Although a variety of antifungal drugs have been developed that preferably attack the fungal cell wall and plasma membrane, these pathogens have acquired novel defense mechanisms that make them resistant to standard treatment. This causes an increase in the incidence of candidiasis and enforces the urgent need for an intensified search for new specifics that could be helpful, alone or synergistically with traditional drugs, for controlling Candida pathogenicity. Currently, numerous reports have indicated the effectiveness of plant metabolites as potent antifungal agents. These substances have been shown to inhibit growth and to alter the virulence of different Candida species in both the planktonic and hyphal form and during the biofilm formation. This review focuses on the most recent findings that provide evidence of decreasing candidal pathogenicity by different substances of plant origin, with a special emphasis on the mechanisms of their action. This is a particularly important issue in the light of the currently increasing frequency of emerging Candida strains and species resistant to standard antifungal treatment.

Therapeutic Drug Monitoring Is a Feasible Tool to Personalize Drug Administration in Neonates Using New Techniques: An Overview on the Pharmacokinetics and Pharmacodynamics in Neonatal Age

Therapeutic drug monitoring (TDM) should be adopted in all neonatal intensive care units (NICUs), where the most preterm and fragile babies are hospitalized and treated with many drugs, considering that organs and metabolic pathways undergo deep and progressive maturation processes after birth. Different developmental changes are involved in interindividual variability in response to drugs. A crucial point of TDM is the choice of the bioanalytical method and of the sample to use. TDM in neonates is primarily used for antibiotics, antifungals, and antiepileptic drugs in clinical practice. TDM appears to be particularly promising in specific populations: neonates who undergo therapeutic hypothermia or extracorporeal life support, preterm infants, infants who need a tailored dose of anticancer drugs. This review provides an overview of the latest advances in this field, showing options for a personalized therapy in newborns and infants.

Combined effect of lasioglossin LL-III derivative with azoles against Candida albicans virulence factors: biofilm formation, phospholipases, proteases and hemolytic activity

Candida albicans has several virulence factors at its disposal, including yeast–hyphal transition associated with biofilm formation, phospholipases, proteases and hemolytic activity, all of which contribute to its pathogenesis. We used synthetic derivative LL-III/43 of antimicrobial peptide lasioglossin LL-III to enhance effect of azoles on attenuation of C. albicans virulence factors. LL-III/43 was able to inhibit initial adhesion or biofilm formation of C. albicans strains at 50 µM. Azoles, however, were ineffective at this concentration. Using fluorescently labeled LL-III/43, we observed that peptide covered C. albicans cells, partially penetrated through their membranes and then accumulated inside cells. LL-III/43 (25 µM) in combination with clotrimazole prevented biofilm formation already at 3.1 µM clotrimazole. Neither LL-III/43 nor azoles were able to significantly inhibit phospholipases, proteases, or hemolytic activity of C. albicans. LL-III/43 (25 µM) and clotrimazole (50 µM) in combination decreased production of these virulence factors, and it completely attenuated its hemolytic activity. Scanning electron microscopy showed that LL-III/43 (50 µM) prevented C. albicans biofilm formation on Ti-6Al-4 V alloy used in orthopedic surgeries and combination of LL-III/43 (25 µM) with clotrimazole (3.1 µM) prevented biofilm formation on urinary catheters. Therefore, mixture of LL-III/43 and clotrimazole is suitable candidate for future pharmaceutical research.

Antifungal Drugs

We reviewed the licensed antifungal drugs and summarized their mechanisms of action, pharmacological profiles, and susceptibility to specific fungi. Approved antimycotics inhibit 1,3-β-d-glucan synthase, lanosterol 14-α-demethylase, protein, and deoxyribonucleic acid biosynthesis, or sequestrate ergosterol. Their most severe side effects are hepatotoxicity, nephrotoxicity, and myelotoxicity. Whereas triazoles exhibit the most significant drug–drug interactions, echinocandins exhibit almost none. The antifungal resistance may be developed across most pathogens and includes drug target overexpression, efflux pump activation, and amino acid substitution. The experimental antifungal drugs in clinical trials are also reviewed. Siderophores in the Trojan horse approach or the application of siderophore biosynthesis enzyme inhibitors represent the most promising emerging antifungal therapies.