Candidemia chronicles:Retrospective analysis of candidemia epidemiology,species distribution,and antifungal susceptibility patterns in Bahrain

BACKGROUND Invasive fungal infections,particularly candidemia,pose significant clinical challenges globally.Understanding local epidemiology,species distribution,and antifungal susceptibility patterns is crucial for effective management despite regional variations.AIM To investigate the epidemiology,species distribution,antifungal susceptibility patterns,and associated risk factors of candidemia among patients in Bahrain from 2021 to 2023.METHODS This retrospective study analyzed demographic data,Candida species distribution,antifungal susceptibility profiles,and risk factors among candidemia patients treated at a tertiary care hospital in Bahrain over three years.Data was collected from medical records and analyzed using descriptive statistics.RESULTS A total of 430 candidemia cases were identified.The mean age of patients was 65.7 years,with a mortality rate of 85.5%.Candida albicans(C.albicans)was the most common species,followed by Candida parapsilosis,Candida tropicalis(C.tropicalis),and emerging multidrug-resistant Candida auris(C.auris).Antifungal susceptibility varied across species,with declining susceptibility to azoles observed,particularly among C.albicans and C.tropicalis.Major risk factors included central venous catheters,broad-spectrum antibiotics,and surgical procedures.CONCLUSION This study highlights the substantial burden of candidemia among older adults in Bahrain,characterized by diverse Candida species.It also concerns levels of antifungal resistance,notably in C.auris.The findings underscore the importance of local epidemiological surveillance and tailored treatment strategies to improve outcomes and mitigate the spread of multidrug-resistant Candida species.Future research should focus on molecular resistance mechanisms and optimizing therapeutic approaches to address this growing public health concern.

Global Burden of Fungal Infections and Antifungal Resistance from 1961 to 2024: Findings and Future Implications

Background: Antifungal resistance (AFR) is a global public health problem with devastating effects, especially among immunocompromised individuals. Addressing AFR requires a One Health approach including Antifungal Stewardship (AFS). This study aimed to comprehensively review global studies published on fungal infections and AFR and to recommend solutions to address this growing problem. Materials and Methods: This was a narrative review that was conducted using published papers on fungal infections, AFR, and AFS between January 1961 and March 2024. The literature was searched using PubMed, Google Scholar, Web of Science, and EMBASE. Results: This found that there has been an increase in fungal infections globally, especially among immunocompromised patients. Due to this increase in fungal infections, there has been a proportionate increase in the use of antifungal agents to prevent and treat fungal infections. This increased use of antifungal agents has worsened the problem of AFR contributing to increased morbidity and mortality. Globally, fungal infections have contributed to 150 million infections annually and 1.7 million deaths per year. By the year 2023, over 3.8 million people died from fungal infections. Addressing AFR remains a challenge because the treatment of antifungal-resistant infections is difficult. Finally, the treatment of fungal infections is a global challenge exacerbated by the limited number of antifungal agents to treat invasive fungal infections. Conclusion: The results of this study indicated that fungal infections and AFR are prevalent across humans, animals, agriculture, and the environment. Addressing this problem requires the provision of solutions such as improving the awareness of AFR, conducting further research on the discovery of new antifungal agents, and implementing AFS programs. If this global problem is not addressed, the morbidity and mortality associated with AFR will continue to rise in the future.

Antifungal pipeline:Is there light at the end of the tunnel?

The misuse and overuse of classic antifungals have accelerated the development of resistance mechanisms,diminishing the efficacy of established therapeutic pathways and necessitating a shift towards alternative targets.Despite this pressing need for new treatments,the antifungal drug pipeline has been largely stagnant for the past three decades,primarily due to the high risks and costs associated with antifungal drug development,compounded by uncertain market returns.Extensive research durations,special patient populations and rigorous regulatory demands pose significant barriers to bringing novel antifungal agents to market.In response,the“push-pull”incentive model has emerged as a vital strategy to invigorate the pipeline and encourage innovation.This editorial critically examines the current clinical landscape and spotlights emerging antifungal agents,such as Fosmanogepix,Ibrexafungerp,and Olorofim,while also unraveling the multifaceted challenges faced in new antifungal drug development.The generation of novel antifungals offers a beacon of hope in the battle against antimicrobial resistance,but it is premature to declare them as definitive solutions.Their future role hinges on thorough clinical validation,costeffectiveness assessments,and continuous post-marketing surveillance.Only through strategic implementation and integration with market strategies we can transform the landscape of antifungal development,addressing both the resistance crisis and the treatment challenges.

Epidemiology, Clinical Features and Antifungal Resistance Profile of Candida auris in Africa: Systematic Review

Candida auris since it discovery in 2009 is becoming a severe threat to human health due to its very quickly spread, its worldwide high resistance to systemic antifungal drugs. In resource-constrained settings where several conditions are met for its emergence and spread, this worrisome fungus could cause large hospital and/or community-based outbreaks. This review aimed to summarize the available data on C. auris in Africa focusing on its epidemiology and antifungal resistance profile. Major databases were searched for articles on the epidemiology and antifungal resistance profile of C. auris in Africa. Out of 2,521 articles identified 22 met the inclusion criteria. In Africa, nearly 89% of African countries have no published data on C. auris. The prevalence of C. auris in Africa was 8.74%. The case fatality rate of C. auris infection in Africa was 39.46%. The main C. auris risk factors reported in Africa were cardiovascular disease, renal failure, diabetes, HIV, recent intake of antimicrobial drugs, ICU admissions, surgery, hemodialysis, parenteral nutrition and indwelling devices. Four phylogenetic clades were reported in Africa, namely clades I, II, III and IV. Candida auris showed a pan-African very high resistance rate to fluconazole, moderate resistance to amphotericin B, and high susceptibility to echinocandins. Finally, C. auris clade-specific mutations were observed within the ERG2, ERG3, ERG9, ERG11, FKS1, TAC1b and MRR1 genes in Africa. This systematic review showed the presence of C. auris in the African continent and a worrying unavailability of data on this resilient fungus in most African countries.

In Vitro Antifungal Activity of Dihydrochelerythrine and Proteomic Analysis in Ustilaginoidea virens

Dihydrochelerythrine(DHCHE)is an isoquinoline compound,which has distinct antifungal activity and can induce apoptosis.The antifungal activity of DHCHE against five rice pathogenic fungi was studied in vitro.At the concentration of 7.5 mg/L,DHCHE exhibited the highest efficacy among tested compounds in inhibiting mycelium growth,with an inhibition rate of 68.8%in Ustilaginoidea virens,which was approximately 2.4 times of that of validamycin(28.7%).After exposure to DHCHE,transmission electron micrographs revealed spores showed incomplete organelles,malformed cell walls and nuclear membranes,as well as irregular lipid spheres.Reactive oxygen species accumulation in treated spores was markedly higher than that in control spores.DHCHE induced cell damage increased in a dose-dependent manner,as indicated by the decrease in mitochondrial membrane potential and initiation of apoptosis.The differences of expression levels of Fip1,ACP1,PMS2 and COX13 that are important for oxidative phosphorylation and mismatch repair pathway were significant,which may be some of the reasons for the induction of apoptosis in DHCHE-treated U.virens.The protein levels of Fip1,ACP1,PMS2 and COX13 agreed with protein fold change ratio from parallel reaction monitoring Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathway of differentially expressed proteins were further analyzed.These findings will help to elucidate the mechanisms associated with antifungal and pro-apoptotic effects of DHCHE on U.virens,thereby aiding the potential development of novel pesticides.

The antifungal properties of terpenoids from the endophytic fungus Bipolaris eleusines

A series of terpenoids(1-17),comprising six new compounds designated bipolariterpenes A-F(1-6)and eleven rec-ognized compounds(7-17),were isolated from the wheat culture of the potato endophytic fungus Bipolaris eleusines.Their structures and stereochemistry were clarified by HRESIMS,NMR,DP4+probability analyses,and computations for electronic circular dichroism(ECD).All compounds are made up of six meroterpenoids,four sesterterpenes and seven sesquiterpenes.Among them,four sesterterpenes(4,5,10,11)were investigated for their antifungal,antibacterial and cytotoxic properties,and six meroterpenoids(1-3,7-9)were evaluated for their antifungal properties.The compounds 7,9,and 10 had substantial antifungal activity against Epidermophyton floccosum at a concentration of 100μM.No antibacterial and cytotoxic activities were observed.

Antifungal activity against Fusarium oxysporum of quinolizidines isolated from three controlled-growth Genisteae plants:structure-activity relationship implications

The Genisteae tribe belongs to the Fabaceae family.The wide occurrence of secondary metabolites,explicitly high-lighting the quinolizidine alkaloids(QAs),characterizes this tribe.In the present study,twenty QAs(1-20),including lupanine(1-7),sparteine(8-10),lupanine(11),cytisine and tetrahydrocytisine(12-17),and matrine(18-20)-type QAs were extracted and isolated from leaves of three species(i.e.,Lupinus polyphyllus(’rusell’hybrid),Lupinus muta-bilis,and Genista monspessulana)belonging to the Genisteae tribe.These plant sources were propagated under greenhouse conditions.The isolated compounds were elucidated by analyzing their spectroscopical data(MS,NMR).The antifungal effect on the mycelial growth of Fusarium oxysporum(Fox)of each isolated QA was then evaluated through the amended medium assay.The best antifungal activity was found to be for compounds 8(IC_(50)=16.5μM),9(IC_(50)=7.2μM),12(IC_(50)=11.3μM),and 18(IC_(50)=12.3μM).The inhibitory data suggest that some QAs could effi-ciently inhibit Fox mycelium growth depending on particular structural requirements deduced from structure-activity relationship scrutinies.The identified quinolizidine-related moieties can be involved in lead structures to develop further antifungal bioactives against Fox.

Development of Molecular Marker Linked with Cercospora Leaf Spot (CLS) Disease Resistance in Vigna radiata, Cloning, and Expression for Evaluating Antifungal Activity against Cercospora canescens

We developed a molecular marker for MAS of mungbean resistant varieties against CLS from the consensus sequence(MB-CLsRG)of identified RGAs(MB-ClsRCaG1 and MB-ClsRCaG2).The MB-CLsRG sequence-specific primer pair was used to screen Cercospora leaf spot(CLS)resistant varieties of mungbean in genomic analysis that showed congruency with phenotypic screening.Validation of molecular marker linkage with CLS resistance was performed using rtPCR in transcriptomic analysis.The sequenced PCR products showed 100%homology with MB-CLsRG sequence and putative disease resistance proteins that confirmed the linkage of molecular marker with CLS resistance in mungbean.The antifungal potential of MB-CLsRG gene encoding protein was assessed.The MB-CLsRG gene sequence was cloned in the E.coli expression vector for recombinant protein production.The recombinant protein was then investigated for its in vitro antifungal potential against Cercospora canescens.The in vitro investigation showed strong antifungal activity of recombinant protein as it restricted the growth of fungal mycelial mass.The results validated the linkage of developed marker with CLS-resistant mungbean varieties;therefore,it can be used to screen resistant varieties from a large population in MAS.Moreover,the recombinant protein of the MB-CLsRG gene sequence revealed antifungal potential,which proved the gene sequence could be suitable to use in transgenic plants technology to develop fungal-resistant transgenic crops.

Profiling of Antifungal Activities from the Leaf Extract of Selected Apiaceae Family Plants against Aspergillus fumigates

Many ethnic plants are used as a source of traditional medicine to cure a variety of illnesses in both humans and animals. Developing secondary metabolites in plants with antifungal characteristics, offer alternative medications for reasonably priced and safe treatments. In the present study, methanolic, ethanolic, hexane and ethyl acetate leaves extracts of fifteen Apiaceae family plants were taken on the premise of their ethno botanical uses. The antifungal activity was assessed against significant fungal strain;Aspergillus fumigates by measuring minimum inhibitory concentration (MIC) and Zone of inhibition compared with standard drug fluconazole. Ethanol and methanol extracts of the plants were more effective than the hexane and ethyl acetate extracts against A. fumigates. Extracts of Cuminum cyminum, Pastinca sativa, Carum carvi, Dacus carota, Centella asiatica, Anthriscus cerefolium, Trachyspermum ammi, Pimpenella anisum and Apium graveolens showed relatively low inhibition effects between 3.5 to 8.5 mm. The MIC value of extracts was determined ranging between 0.8 to 0.43 μg/ml. The extract of Petroselinum crispum, Foeniculum vulgare, Ferula assaefoetida, Bunium persicum, Anethum graveolens and Coriander sativum could be considered as potential source of antifungal compounds for treating diseases in humans. Conclude remarks that these six extracts show astonishing fungicidal properties that can be used to discover drugs of very high potential.

In Vitro Evaluation of the Antifungal Activity of Essential Oils of Thymus vulgaris and Cymbopogon citratus on Some Strains of Sclerotinia sclerotiorum, Agent Responsible for White Rot of Beans

The present work was aimed to the study of the antifungal activity of essential oils of two aromatic plants against three strains of Sclerotinia sclerotiorum responsible for white rot of bean. The two essential oils (EO) of the studied plants: Thymus vulgaris (HET) and Cymbopogon citratrus (HEC), used at different concentrations: C1 (0.75 ml/ml), C2 (1.5 ml/ml) and C3 (3 ml/ml) presented significant inhibitory activities on the three tested fungal strains namely Bia 1, Bia 2, and Njo 2. Two control treatments (T-: containing no antifungal substance and T+: synthetic fungicide) were also used. The antifungal activity here is related to the inhibition of mycelial growth especially with high concentrations of essential oils. Thus, against S. sclerotiorum, HET showed the highest activity comparable to that of T+ (100% inhibition) at all concentrations on the Bia 1 and Bia 2 strains and at concentration C3 on the Njo 2 strain compared to that of HEC, which certainly inhibited the mycelial growth of the different strains considerably (with a maximum of 78.15% on the Njo 2 strain) but not completely. According to their sensitivity, the Bia 2 strain showed a higher sensitivity to essential oils than the others while the Njo 2 strain was more aggressive. On the basis of MIC50 and MIC90 obtained on the Njo 2 strain, the HET turns out to be the most efficient with respective lower values of (1.73 and 23.34 ml/ml) against (4.76 and 26.03 ml/ml) for the HEC. These EO could thus be exploited as biodegradable antifungal substances, likely to control white rot of bean.

Efficacy and Safety Assessment of Antifungal Sequential Therapy from Micafungin to Liposomal Amphotericin B for Antibiotics-Refractory Febrile Neutropenia in Patients with Hematologic Malignancies

Invasive fungal infections are a major challenging problem in the management of febrile neutropenia (FN) in patients with hematologic malignancies. Liposomal amphotericin B (L-AmB) or micafungin (MCFG) has been widely used as a first-line empirical antifungal therapy for suspected fungal infection in such patients. However, there are several issues in patients receiving these agents: drug related toxicities for L-AmB and breakthrough fungal infections for MCFG. In order to make the best use of these 2 agents, we conducted a prospective study of sequential therapy from MCFG to L-AmB, and evaluated the efficacy and safety of this strategy in FN patients with hematologic malignancies. A total of 18 patients were enrolled, and 11 patients who fulfilled the protocol defined criteria were evaluated. Underlying diseases consisted of acute leukemia (n = 9), non-Hodgkin lymphoma (n = 1), and myelodysplastic syndrome (n = 1). Treatment success was achieved in 8 patients (72.7%). Drug-related adverse events occurred in 8 patients (72.7%). All of those adverse events except one case were below grade 2. Three patients required discontinuation of L-AmB. Although our empirical antifungal sequential therapy seems to be encouraging for antibiotics-refractory FN in patients with hematologic malignancies, further investigation in large-scale studies is warranted.

Antifungal Activity of Extracts from Clerodendrum Bungei Leaves against Two Species of Phytopathogens

The test was undertaken to reveal the antifungal activity of extracts from Clerodendrum bungei leaves against Pestalotia and Rhizoctonia solani, the results showed that optimal condition for best antifungal activity of extracts against pestalotia and Rhizoctonia solani are as follows： material-liquid ratio of 1：6,75% ethanol as extracting solvent, reflux at 90℃ for 1.5 h. The substances with good dissolubility in ethanol and water solution such as organic acid, bioflavonoid and alkaloid are main antifungal bioactive substances in Clerodendrun bungei.

A New Antifungal Flavonol Glycoside from Hypericum perforatum

In addition to six known flavonoids quercitrin, hyperoside, avicularin, rutin, quercetin and kaemferol, a new flavonol glycoside named 6″_O_acetyl quercetin 3_O_β_ D _alloside (1) was isolated from the aerial parts of Hypericum perforatum L. The structures were determined on the basis of spectroscopic methods (UV, IR, FAB_MS, 1H_NMR and 13 C NMR). Antifungal assay of all compounds showed that metabolite 1, quercitrin and quercetin were inhibitory to the growth of phytopathogenic fungus Helminthosporium sativum Pamel King et Bakke with minimum inhibitory concentrations (MICs) of 25, 50 and 50 μg/mL, respectively. Moreover, glycoside 1 and quercitrin were also shown to be able to inhibit the growth of Fusarium graminearum Schw. with MIC of 100 μg/mL. The MICs of ketoconazole used as control against the test fungi were 0.5 μg/mL in our assay.

Screening of Two Biocontrol Strains of Bacillus subtilis against Ginseng Soil-borne Disease and Their Antifungal Activities

[ Objective] The paper was to obtain biocontrol strains with good control effects against ginseng soil-borne disease through screening. [ Method] Dilu- tion plate method and plate confrontation culture method were used to isolate and screen biocontrol bacteria from the rhizosphere soil of diseased ginseng. The strains were identified through morphology, physiological and biochemical characteristics and 16S rDNA. [ Result ] With Rhizoctonia solani, Fusarium oxysporum and Fu- sarium solani as the indicator strains, two biocontrol strains B59 and X1 with strong antagonistic effects were screened from the rhizosphere soil of diseased ginseng in Tieli farm of Heilongjiang Province, and they were identified to be Bacillus subtilis. The inhibition rates of two biocontrol strains against eight different fungi were all greater than 90%. The primary study indicated that B59 and X1 strains could secrete antifungal active substances. [ Conclusion] Two biocontrol Bacillus subti- lis strains 1359 and X1 all had strong antagonistic effect against ginseng soil-borne disease, which had certain potential for development and utilization.

Synthesis of a New Series of Chalcone Derivatives and Their Antifungal Activities

To study the antifungal effect of chalcone derivatives. Methods Sixteenchalcone derivatives were synthesized and confirmed by ~1H NMR and IR spectra, and tested forantifungal activity against four common pathogenic fungi. Their structure-activity relationship isdiscussed. Results Among 16 title compounds, there were 5 new compounds, which have not beenreported before. The preliminary antifungal test showed that all title compounds exhibitedantifungal activities to a certain extent. The activity of compound 8 against Trichophyton rubrumhad a potency equal to that of fluconazole, with a MIC of 4 μg·mL^(-1) . Conclusion Sixteenchalcones were prepared and their antifungal activities against four common pathogenic fungi invitro were examined. Some of them exhibited antifungal activities to a certain extent.

Antifungal Effect of Streptomyces 702 Antifungal Monomer Component DZP8 on Rhizoctonia solani and Magnaporthe grisea

The aim of this study was to investigate the in vitro antifungal effects of antifungal monomer component DZP8 isolated from Streptomyces 702 on the mycelium growth, sclerotium formation and germination of Rhizoctonia solani and on the mycelium growth, conidial formation, germination, appressorium formation of Magnaporthe grisea. The results showed that the antifungal monomer component DZP8 has strong antifungal effect on both the R. solani and M. grisea. The EC50 and EC90 of DZP8 were 1.81 and 3.35 μg/ml on Ft. solani respectively, and 37.01 and 136.21 μg/ml on M. grisea respectively. Under the treatment of 48.01 μg/ml DZP8, the sclerotium formation rate of R. solani was just 39.21%, the formation time delayed by 216 h and the dry weight decreased by 81.37% in comparison the con- trol; and 33.51 μg/ml DZP8 significantly inhibited the sclerotium germination. In the presence of 160.08 μg/ml DZP8, the sporulation of M. grisea was just 9.29% of control sample; 20.14 μg/ml DZP8 inhibited the conidial germination suppression rate by 95.16%, and the appressorium formation by 100%.

Screening and Identification of Myxobacterias with Antifungal Activity

[ Objective] The paper was to screen myxobacteria with antifungal activity, and identify its species. [ Method] 237 myxobacteria were isolated and pu- rified from 200 copies of soil samples collected from 23 provinces in China. The strains were fermented in four different media, and the fermentation products were extracted by methanol to obtain metabolites. With Candida albicans as the model, the secondary metabolites were carried out high-throughput screening. [ Result ] A strain of myxohacteria numbered ZJ2 was obtained after secondary screening, its secondary metabolites had activities against G. albicans. 16S rDNA cloning and sequencing results showed that ZJ2 was Myxococcus fidvus. [ Conclusion ] The secondary metabolites of ZJ2 strain had bioactive substances with significant inhibi- tion effect against the growth of C. albicans, which had potential pharmaceutical research and development value.

Isolation and Identification of Antifungal Bacterial Strain KL-1 against Plant Wilt Disease

[Objective] The antifungal bacteria of plant wilt disease was screened and identified to provide foundation for the study on bio-control preparation of plant wilt disease.[Method] Confrontation culture method was adopted to screen the bio-control bacteria with good antifungal effect against plant wilt disease,Biolog bacteria automatic identification system and 16S rDNA sequence analysis method were selected to identify its taxonomic status,the biological safety of the strain towards cotton and mice was also determined.[Result] 12 bacterial strains were isolated from rhizosphere of cotton.Among those strains,5 isolates showed antifungal activity against F.decemcellulare Brick,F.oxysporum f.sp.Diathi,F.oxysporum f.sp.vasinfectum.The antifungal effect of KL-1 strain against three target strains of pathogen reached 69.09%,80.78% and 78.89% respectively.Identification results of Biolog bacteria automatic identification system and 16S rDNA sequence analysis method showed that KL-1strain was Bacillus amyloliquefaciens;primary determination results of biological safety also showed that the strain KL-1 was safe and non-toxic towards cotton and mice.[Conclusion] KL-1strain of B.amyloliquefaciens had antifungal effect against several pathogens of plant wilt diseases,which was safe and non-toxic towards cotton and mice,being the bio-control strain with research and development potential.

Inhibitory Effect of Antifungal Substances from Chaetomium globosum ND35 on Pathogenic Fungi of Valsa canker

[Objective] Inhibition mechanism of the antifungal substances from Chaetomium globosum ND35 against pathogenic fungi of Valsa canker was investigated.[Method] The inhibitory effect of antifungal substances （AFS） produced by endophytic C. globosum ND35 on pathogenic fungi of Valsa canker was studied by means of dual culture,extraction,thin layer chromatography and bioassay of antifungal activity. [Result] The crude extracts of AFS could strongly inhibit Valsa sordida and V. mali. The suppression percentage of mycelial growth of two pathogenic fungi were 66.4% and 72.6%,respectively. The inhibition percentages of conidia germination of two pathogenic fungi were 92.2% and 80.4%,respectively. Separation of thin layer chromatography and bioassay of antifungal activity indicated that the fraction No.2 of AFS played an important role in the process of inhibition on pathogenic fungi,causal agents of Valsa canker. [Conclusion] The antifungal substances from C. globosum ND35 is potential for biological control on Valsa canker.

Antifungal Activity of Botanical Extracts against Botrytis cinerea and Alternaria solani

[Objective] The antifungal activity of the extracts from,Atractylodes macracephal Koidz and Pulsatilla chinensis Bunge Regel,against Botrytis cinerea and Alternaria solani were studied under the condition of laboratory,in order to develop and utilize these two plants.[Method] The mycelium growth rate test was applied to measure the antifungal activities of extracts against fungi.[Result] the extracts of all the two plants showed strong antifungal activity against the target pathogenic fungi,especially the antifungal activity of the extract from Pulsatilla chinensis Bunge Regel was stronger and more stable.The inhibition rate to the mycelium growth of Botrytis cinerea was 80.25%.At the same concentration,the extract from Atractylodes macracephal Koidz showed little inhibition to Botrytis cinerea and Alternaria solani.The petrolelum ether extract of Atractylodes macracephal Koidz showed stronger antifungal activities and the EC50 was 5.31 mg/ml,and the n-butanol extract of Pulsatilla chinensis Bunge Regel showed stronger antifungal activities and the EC50 was 2.93 mg/ml.[Conclusion] The extracts from Pulsatilla chinensis Bunge Regel showed the stronger antifungal activity against Botrytis cinerea and Alternaria solani.