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1.
Iran J Microbiol ; 16(2): 280-284, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38854988

ABSTRACT

Background and Objectives: Amphotericin B is a broad-spectrum antifungal agent commonly used to treat Candida haemulonii infection. C. haemulonii was isolated from patients reported to be intrinsically resistant to amphotericin B, encoded by the ERG2 and ERG11 genes. However, there have been limited studies concerning amphotericin B-resistant C. haemulonii in Indonesia. The objective of this study is to explore the phenotypic and genotypic characteristics (ERG2 and ERG11) of C. haemulonii isolated from the ICU of a referral hospital in Indonesia. Materials and Methods: Identification and susceptibility tests were conducted using VITEK2. Thereafter, DNA was extracted and amplified using conventional PCR followed by DNA sequencing (Sanger method). Results: The results of the phenotypic susceptibility test showed that all C. haemulonii were resistant to amphotericin B. ERG2 and ERG11 sequences showed the same amino acid sequence and corresponded to references that are resistant to amphotericin B. Conclusion: The resistant properties of C. haemulonii against amphotericin B found in this study require further exploration, including comparing resistant and sensitive C. haemulonii to amphotericin B. In addition, it is necessary to analyze other genes besides ERG2 and ERG11.

2.
Iran J Microbiol ; 16(2): 273-279, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38854989

ABSTRACT

Background and Objectives: The presence of fungi in the respiratory tract as mycobiome, particularly Candida species (spp.), remains a serious problem due to increasing numbers of immunocompromised patients. The confirmed reliable existence of these pathogens due to frequent colonization is essential. This investigation aimed to recognize Candida spp. among isolates from bronchoalveolar lavage of immunocompromised and critically ill patients and to evaluate their susceptibility to antimycotic drugs. Materials and Methods: Bronchoalveolar lavage fluid was collected from 161 hospitalized patients presenting with suspected respiratory fungal infection /colonization. The specimens were examined by standard molecular and mycological assays. Candida spp. were recognized with sequence assessment of the D1-D2 section of the large subunit ribosomal DNA. The susceptibility of Candida isolates to common antimycotic drugs was distinguished by standard broth microdilution. Results: Seventy-one clinical isolates of Candida spp. were recognized. Candida albicans was the most frequent, followed by C. glabrata, C. krusei (Pichia kudriavzevii), C. dubliniensis, C. parapsilosis, and C. tropicalis. We found 5.1% of C. albicans isolates and 8% of C. glabrata isolates to show resistance to fluconazole. The whole of the Candida spp. were sensitive to amphotericin B and caspofungin. Conclusion: This study demonstrated that C. albicans and C. glabrata are the most common isolates of bronchoalveolar lavage fluid in patients, and the drug susceptibility screening confirmed that amphotericin B and caspofungin are effective against Candida spp. but some C. glabrata and C. albicans isolates showed resistance to fluconazole.

3.
Iran J Microbiol ; 16(2): 263-272, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38854986

ABSTRACT

Background and Objectives: Early diagnosis of candidemia is of vital importance in reducing mortality and morbidity. The main objective of the study was to determine the TTP (Time to Positivity) of different species of Candida causing bloodstream infection and to see whether TTP can help differentiate Candida glabrata which is frequently fluconazole resistant from Fluconazole sensitive Candida. Materials and Methods: TTP (Time to positivity) and AAT (Appropriate Antifungal therapy) were noted for Blood cultures becoming positive for Candida. Presence of Risk factors for candidemia like prolonged ICU stay, neutropenia, Total Parenteral Nutrition (TPN), use of steroids , broad spectrum antibiotics, use of Central Venous Catheter, Foleys catheter were also analyzed. Results: The most frequent isolates were Candida parapsilosis, Candida tropicalis and Candida albicans. The median TTP for all Candida isolates in our study was 34 hours. The diagnostic sensitivity of TTP for detecting C. glabrata and C. tropicalis in patients with candidemia was 88% and 85% respectively. TTP showed that there was no difference in survival between TTP <24 hrs. and > 24hrs. Initiation of antifungal therapy <24 hours and > 24hrs after onset of candidemia had no association with survival. Conclusion: Longer TTP maybe predictive of C. glabrata while shorter TTP may be predictive of C. tropicalis. In our study we found that fluconazole resistant Candida causing blood stream infection is quite unlikely if the TTP of the isolate is <48hrs.

4.
Radiol Case Rep ; 19(8): 3443-3448, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38872750

ABSTRACT

Mycotic pseudoaneurysms of the iliac arteries are extremely rare and are caused by infection of the artery wall. It is difficult to diagnose early due to its silent manifestation. We present a case of a 64-year-old man with an isolated left common iliac artery pseudoaneurysm caused by Candida albicans who presented with thrombophlebitis, abdominal pain, nausea and vomiting associated with fever, which was successfully treated with interposition grafting and antibiotic therapy. We present this case to highlight that aneurysms and other vascular lesions can affect different arteries in the body and may therefore only be discovered during routine investigations of non-specific symptoms.

6.
Arch Microbiol ; 206(7): 293, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38850421

ABSTRACT

Fungal infections are incurring high risks in a range from superficial mucosal discomforts (such as oropharyngeal candidiasis and vulvovaginal candidiasis) to disseminated life-threatening diseases (such as invasive pulmonary aspergillosis and cryptococcal meningitis) and becoming a global health problem in especially immunodeficient population. The major obstacle to conquer fungal harassment lies in the presence of increasing resistance to conventional antifungal agents used in newly clinically isolated strains. Although recombinant cytokines and mono-/poly-clonal antibodies are added into antifungal armamentarium, more effective antimycotic drugs are exceedingly demanded. It is comforting that the development of fungal vaccines and adjuvants opens up a window to brighten the prospective way in the diagnosis, prevention and treatment of fungal assaults. In this review, we focus on the progression of several major fungal vaccines devised for the control of Candida spp., Aspergillus spp., Cryptococcus spp., Coccidioides spp., Paracoccidioides spp., Blastomyces spp., Histoplasma spp., Pneumocystis spp. as well as the adjuvants adopted. We then expound the interaction between fungal vaccines/adjuvants and host innate (macrophages, dendritic cells, neutrophils), humoral (IgG, IgM and IgA) and cellular (Th1, Th2, Th17 and Tc17) immune responses which generally experience immune recognition of pattern recognition receptors, activation of immune cells, and clearance of invaded fungi. Furthermore, we anticipate an in-depth understanding of immunomodulatory properties of univalent and multivalent vaccines against diverse opportunistic fungi, providing helpful information in the design of novel fungal vaccines and adjuvants.


Subject(s)
Adjuvants, Immunologic , Fungal Vaccines , Mycoses , Fungal Vaccines/immunology , Humans , Mycoses/prevention & control , Mycoses/immunology , Animals , Fungi/immunology
7.
Microbiol Res ; 286: 127797, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38851008

ABSTRACT

Candida auris has drawn global attention due to its alarming multidrug resistance and the emergence of pan resistant strains. C. auris poses a significant risk in nosocomial candidemia especially among immunocompromised patients. C. auris showed unique virulence characteristics associated with cell wall including cell polymorphism, adaptation, endurance on inanimate surfaces, tolerance to external conditions, and immune evasion. Notably, it possesses a distinctive cell wall composition, with an outer mannan layer shielding the inner 1,3-ß glucan from immune recognition, thereby enabling immune evasion and drug resistance. This review aimed to comprehend the association between unique characteristics of C. auris's cell wall and virulence, resistance mechanisms, and immune evasion. This is particularly relevant since the fungal cell wall has no human homology, providing a potential therapeutic target. Understanding the complex interactions between the cell wall and the host immune system is essential for devising effective treatment strategies, such as the use of repurposed medications, novel therapeutic agents, and immunotherapy like monoclonal antibodies. This therapeutic targeting strategy of C. auris holds promise for effective eradication of this resilient pathogen.

8.
Environ Sci Nano ; 11(2): 637-644, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38841652

ABSTRACT

Infections caused by fungi are emerging global health challenges that are exacerbated by the formation of fungal biofilms. Further challenges arise from environmental contamination with antifungal agents, which promotes environmental acquisition of antifungal resistance. We report the generation of an efficient, sustainable, all-natural antifungal nanotherapeutic based on the integration of an antimicrobial natural essential oil into a gelatin-based nanoemulsion platform. Carvacrol-loaded gelatin nanoemulsions penetrated Candida albicans biofilms, resulting in death of C. albicans cells in biofilms, and displayed selective biofilm elimination without harmful effects on fibroblast cells in a fungal biofilm-mammalian fibroblast co-culture model. Furthermore, the nanoemulsions degraded in the presence of physiologically relevant biomolecules, reducing the potential for environmental pollution and ecotoxicity. Overall, the sustainability, and efficacy of the described gelatin nanoemulsion formulation provides an environmentally friendly strategy for treating biofilm-associated fungal infections, including those caused by drug-resistant fungi.

9.
Front Cell Infect Microbiol ; 14: 1375872, 2024.
Article in English | MEDLINE | ID: mdl-38846355

ABSTRACT

Introduction: Pseudomonas aeruginosa is notorious for its multidrug resistance and its involvement in hospital-acquired infections. In this study, 20 bacterial strains isolated from soil samples near the Hindan River in Ghaziabad, India, were investigated for their biochemical and morphological characteristics, with a focus on identifying strains with exceptional drug resistance and pyocyanin production. Methods: The isolated bacterial strains were subjected to biochemical and morphological analyses to characterize their properties, with a particular emphasis on exopolysaccharide production. Strain GZB16/CEES1, exhibiting remarkable drug resistance and pyocyanin production. Biochemical and molecular analyses, including sequencing of its 16S rRNA gene (accession number LN735036.1), plasmid-curing assays, and estimation of plasmid size, were conducted to elucidate its drug resistance mechanisms and further pyocynin based target the Candida albicans Strain GZB16/CEES1 demonstrated 100% resistance to various antibiotics used in the investigation, with plasmid-curing assays, suggesting plasmid-based resistance gene transmission. The plasmid in GZB16/CEES1 was estimated to be approximately 24 kb in size. The study focused on P. aeruginosa's pyocyanin production, revealing its association with anticandidal activity. The minimum inhibitory concentration (MIC) of the bacterial extract against Candida albicans was 50 µg/ml, with a slightly lower pyocyanin-based MIC of 38.5 µg/ml. Scanning electron microscopy illustrated direct interactions between P. aeruginosa strains and Candida albicans cells, leading to the destruction of the latter. Discussion: These findings underscore the potential of P. aeruginosa in understanding microbial interactions and developing strategies to combat fungal infections. The study highlights the importance of investigating bacterial-fungal interactions and the role of pyocyanin in antimicrobial activity. Further research in this area could lead to the development of novel therapeutic approaches for combating multidrug-resistant infections.


Subject(s)
Antifungal Agents , Candida albicans , Drug Resistance, Multiple, Bacterial , Microbial Sensitivity Tests , Plasmids , Pseudomonas aeruginosa , Pyocyanine , RNA, Ribosomal, 16S , Soil Microbiology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/metabolism , Pyocyanine/metabolism , Drug Resistance, Multiple, Bacterial/genetics , Antifungal Agents/pharmacology , Candida albicans/drug effects , Candida albicans/genetics , Candida albicans/growth & development , RNA, Ribosomal, 16S/genetics , India , Plasmids/genetics , Anti-Bacterial Agents/pharmacology , Antibiosis
10.
Front Glob Womens Health ; 5: 1339821, 2024.
Article in English | MEDLINE | ID: mdl-38847001

ABSTRACT

Introduction: Vaginal Candida colonization (CC) can lead to vulvovaginal candidiasis, the second most prevalent vaginal condition worldwide, and has been associated with adverse birth outcomes. However, no data on CC in the Democratic Republic of the Congo are available. We investigated the prevalence, Candida species, clinical correlates, risk factors and pregnancy outcomes in women with CC in the second trimester of pregnancy. Material and methods: In Bukavu, the Democratic Republic of the Congo, pregnant women were recruited during antenatal care between 16 and 20 weeks of gestation from January 2017 to October 2017 and followed until delivery. Sociodemographics, sexual behavioral, hygienic and clinical characteristics, microbiological data and pregnancy outcomes were collected. Candida detection and speciation was performed with microscopy (Gram-stained smears and wet-mount) and/or quantitative PCR. Multivariate regression models were used to estimate the different associations with CC. Results: The prevalence of CC by wet mount, microscopy of Gram-stain smears and qPCR was 27.9%, 28.1% and 38.2%, respectively. C. albicans was the most prevalent Candida species (91.0%). Previous genital infections, an intermediate vaginal microbiota, bacterial vaginosis, and the use of pit toilets were risk factors for CC. Clinically, CC was associated with itching only. Women with CC had twice the odds for preterm birth, if Candida concentration was high, the odds were four times higher. Conclusions: In Bukavu, the Democratic Republic of the Congo, the prevalence of CC was high and associated with microbiological and modifiable risk factors. Screening and treatment for CC during antenatal care should be investigated as a possible strategy to reduce preterm birth.

11.
Front Pediatr ; 12: 1397456, 2024.
Article in English | MEDLINE | ID: mdl-38827222

ABSTRACT

Urinary tract infections (UTIs) associated with indwelling urinary catheterization (IUC) in premature newborns (PNBs) pose a significant challenge in neonatal intensive care units (NICUs) due to the vulnerability of this population to infections and the necessity of invasive procedures. While bacterial UTIs have historically been predominant, there is a rising incidence of fungal pathogens, particularly non-albicans Candida strains like Candida glabrata and Candida tropicalis, attributed to broad-spectrum antibiotic use. Diagnosis of fungal UTIs in a PNB relies on culturing Candida spp. from properly collected urine samples, particularly critical in very low birth weight (VLBW) PNBs because of the risk of invasive candidiasis and associated complications. We present a case of an extremely premature newborn (EPNB) successfully treated for a UTI caused by C. glabrata with micafungin. Our case exhibits micafungin as a potentially safe and effective alternative for treating C. glabrata UTIs in neonates.

12.
Int J Nanomedicine ; 19: 4941-4956, 2024.
Article in English | MEDLINE | ID: mdl-38828194

ABSTRACT

Background: Due to its prevalence, recurrence, and the emergence of drug-resistance, Candida vaginitis significantly impacts the well-being of women. Although cinnamon essential oil (CEO) possesses antifungal activity, its hydrophobic properties limit its clinical application. Purpose: To overcome this challenge, a nanoemulsification technology was employed to prepare cinnamon essential oil-nanoemulsion (CEO@NE), and its therapeutic efficacy and action mechanism for Candida vaginitis was investigated in vivo and in vitro. Materials and Methods: CEO@NE, composed of 4% CEO, 78% distilled water, and 18% Tween 80, was prepared by ultrasonic nanoemulsification. The physical properties, anti-Candida activity, cytotoxicity, immunomodulatory potential and storage stability of CEO@NE were explored. Subsequently, the effect of intravaginal CEO@NE treatment on Candida vaginitis was investigated in mice. To comprehend the possible mechanism of CEO@NE, an analysis was conducted to ascertain the production of intracellular reactive oxygen species (ROS) in C. albicans. Results: CEO@NE, with the droplet size less than 100 nm and robust storage stability for up to 8 weeks, exhibited comparable anti-Candida activity with CEO. CEO@NE at the concentration lower than 400 µg/mL had no cytotoxic and immunomodulatory effects on murine splenocytes. Intravaginal treatment of CEO@NE (400 µg/mL, 20 µL/day/mouse for 5 consecutive days) curbed Candida colonization, ameliorated histopathological changes, and suppressed inflammatory cytokine production in mice intravaginally challenged with C. albicans. Notably, this treatment preserved the density of vaginal lactic acid bacteria (LAB) crucial for vaginal health. Co-culturing C. albicans with CEO@NE revealed concentration-dependent augmentation of intracellular ROS generation and ensuing cell death. In addition, co-culturing LPS-stimulated murine splenocytes with CEO@NE yielded a decrease in the generation of cytokines. Conclusion: This discovery provides insight into the conceivable antifungal and anti-inflammatory mechanisms of CEO@NE to tackle Candida vaginitis. CEO@NE offers a promising avenue to address the limitations of current treatments, providing novel strategy for treating Candida vaginitis.


Subject(s)
Antifungal Agents , Candida albicans , Candidiasis, Vulvovaginal , Cinnamomum zeylanicum , Emulsions , Oils, Volatile , Female , Animals , Oils, Volatile/chemistry , Oils, Volatile/pharmacology , Oils, Volatile/administration & dosage , Candidiasis, Vulvovaginal/drug therapy , Candida albicans/drug effects , Antifungal Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/administration & dosage , Mice , Administration, Intravaginal , Cinnamomum zeylanicum/chemistry , Emulsions/chemistry , Reactive Oxygen Species/metabolism , Humans , Nanoparticles/chemistry , Mice, Inbred BALB C
13.
In Silico Pharmacol ; 12(1): 48, 2024.
Article in English | MEDLINE | ID: mdl-38828443

ABSTRACT

The continuous search for more effective options against well-known pathogens such as Candida albicans remains the rationale for the search for novel lead compounds from various sources. This study aims to investigate the chemical structure, chemical properties, of 5-(2-((5-(((1S,3R) -3-(5-acetamido-1,3,4-thiadiazolidin-2-yl) cyclopentyl) methyl)-1,3,4-thiadiazolidin-2-yl)amino)-2-oxoethyl)-2-methyl-2,3-dihydro-1H-pyrazol-3-ide designated ATCTP using DFT method ωB97XD/-311 + + g(2d, 2p) and the biological potential of compound ATCTP against Candida albicans using molecular docking and ADMET studies. Geometry optimization was carried out in DMSO, ethanol. gas and water revealing minute discrepancies in bond length and wider differences in bond angles. Frontier molecular orbital investigations reveal HOMO-LUMO energy gap magnitude in decreasing order of ATCTP_Gas > ATCTP_Water > ATCTP_ethanol > ATCTP_DMSO inferring that water influences chemical stability of the compound the most compared to ethanol and DMSO. Density of state investigations have revealed electron density contributions at corresponding energy peaks. In silico pharmacokinetic predicts ATCTP not to be cytotoxic, hepatotoxic, immunotoxic or mutagenic but probable mutagen. Molecular docking investigation of ATCTP against aspartic proteinase of Candida albicans (ID: 2QZX) in comparison with standard drug Fluconazole. Compound ATCTP had higher binding affinity (- 8.1 kcal/mol) compared to that of the standard drug fluconazole (- 5.6 kcal/mol) which records 4 conventional hydrogen interactions compared to 2 formed in the interaction of ATCTP + 2QZX. ATCTP also reports binding affinity of - 7.2 kcal/mol which reportedly surpassed that of 2QZX interaction with fluconazole (- 5.7 kcal/mol). ATCTP binds with lanosterol14-α-demethylase (5v5z) with binding affinity of - 9.7 kcal/mol binding to active site amino acid residues of the protein compared to fluconazole + 5v5z (- 8.0 kcal/mol). ATCTP is therefore recommended to be a lead compound for the possible design of a new and more effective anti-candida therapeutic compound.

14.
Microbiol Mol Biol Rev ; : e0002123, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38832801

ABSTRACT

SUMMARYA significant increase in the incidence of Candida-mediated infections has been observed in the last decade, mainly due to rising numbers of susceptible individuals. Recently, the World Health Organization published its first fungal pathogen priority list, with Candida species listed in medium, high, and critical priority categories. This review is a synthesis of information and recent advances in our understanding of two of these species-Candida albicans and Candida glabrata. Of these, C. albicans is the most common cause of candidemia around the world and is categorized as a critical priority pathogen. C. glabrata is considered a high-priority pathogen and has become an increasingly important cause of candidemia in recent years. It is now the second most common causative agent of candidemia in many geographical regions. Despite their differences and phylogenetic divergence, they are successful as pathogens and commensals of humans. Both species can cause a broad variety of infections, ranging from superficial to potentially lethal systemic infections. While they share similarities in certain infection strategies, including tissue adhesion and invasion, they differ significantly in key aspects of their biology, interaction with immune cells, host damage strategies, and metabolic adaptations. Here we provide insights on key aspects of their biology, epidemiology, commensal and pathogenic lifestyles, interactions with the immune system, and antifungal resistance.

15.
Open Forum Infect Dis ; 11(6): ofae264, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38835496

ABSTRACT

Background: Reports of fluconazole-resistant Candida parapsilosis bloodstream infections are increasing. We describe a cluster of fluconazole-resistant C parapsilosis bloodstream infections identified in 2021 on routine surveillance by the Georgia Emerging Infections Program in conjunction with the Centers for Disease Control and Prevention. Methods: Whole-genome sequencing was used to analyze C parapsilosis bloodstream infections isolates. Epidemiological data were obtained from medical records. A social network analysis was conducted using Georgia Hospital Discharge Data. Results: Twenty fluconazole-resistant isolates were identified in 2021, representing the largest proportion (34%) of fluconazole-resistant C parapsilosis bloodstream infections identified in Georgia since surveillance began in 2008. All resistant isolates were closely genetically related and contained the Y132F mutation in the ERG11 gene. Patients with fluconazole-resistant isolates were more likely to have resided at long-term acute care hospitals compared with patients with susceptible isolates (P = .01). There was a trend toward increased mechanical ventilation and prior azole use in patients with fluconazole-resistant isolates. Social network analysis revealed that patients with fluconazole-resistant isolates interfaced with a distinct set of healthcare facilities centered around 2 long-term acute care hospitals compared with patients with susceptible isolates. Conclusions: Whole-genome sequencing results showing that fluconazole-resistant C parapsilosis isolates from Georgia surveillance demonstrated low genetic diversity compared with susceptible isolates and their association with a facility network centered around 2 long-term acute care hospitals suggests clonal spread of fluconazole-resistant C parapsilosis. Further studies are needed to better understand the sudden emergence and transmission of fluconazole-resistant C parapsilosis.

16.
Bio Protoc ; 14(6): e4958, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38841286

ABSTRACT

Candida glabrata is an opportunistic pathogen that may cause serious infections in an immunocompromised host. C. glabrata cell wall proteases directly interact with host cells and affect yeast virulence and host immune responses. This protocol describes methods to purify ß-1,3-glucan-bonded cell wall proteases from C. glabrata. These cell wall proteases are detached from the cell wall glucan network by lyticase treatment, which hydrolyzes ß-1,3-glucan bonds specifically without rupturing cells. The cell wall supernatant is further fractioned by centrifugal devices with cut-offs of 10 and 50 kDa, ion-exchange filtration (charge), and gel filtration (size exclusion). The enzymatic activity of C. glabrata proteases is verified with MDPF-gelatin zymography and the degradation of gelatin is visualized by loss of gelatin fluorescence. With this procedure, the enzymatic activities of the fractions are kept intact, differing from methods used in previous studies with trypsin digestion of the yeast cell wall. The protein bands may be eventually located from a parallel silver-stained gel and identified with LC-MS/MS spectrometry. The advantage of this methodology is that it allows further host protein degradation assays; the protocol is also suitable for studying other Candida yeast species. Key features • Uses basic materials and laboratory equipment, enabling low-cost studies. • Facilitates the selection and identification of proteases with certain molecular weights. • Enables further functional studies with host proteins, such as structural or immune response-related, or enzymes and candidate protease inhibitors (e.g., from natural substances). • This protocol has been optimized for C. glabrata but may be applied with modifications to other Candida species.

17.
Int J Biol Macromol ; : 132879, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38838899

ABSTRACT

The base of Flammulina velutipes (F. velutipes) stipe are agricultural wastes generated during the cultivation of edible fungus F. velutipes with high amount of chitin. Herein, this study firstly prepared chitosan from the base of F. velutipes stipe (FVC) and its structure was identified. It was confirmed that FVC acted as an antigenic substance to activate the immune system in vivo and in vitro, drive T cells to differentiate into Th-17 cells, and establish an effective mucosal immune barrier in the oral cavity, thus inhibited C. albicans infection; On the other hand, FVC maintained the oral flora stability and significantly reduced the abundance of Streptococcus spp., which was closely related to C. albicans infection. On this basis, the inhibitory effects of FVC on oral pathogens Streptococcus mutans and Lactobacillus casei associated with C. albicans infection were further verified, and it was demonstrated that FVC effectively interfered with the growth of pathogenic bacteria by inducing the production of intracellular ROS to damage bacterial cells. Therefore, FVC may be potentially exploited as a novel approach to the prevention and treatment of oral C. albicans infection.

18.
Microbiol Spectr ; : e0354023, 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38842332

ABSTRACT

Candida auris, initially identified in 2009, has rapidly become a critical concern due to its antifungal resistance and significant mortality rates in healthcare-associated outbreaks. To date, whole-genome sequencing (WGS) has identified five unique clades of C. auris, with some strains displaying resistance to all primary antifungal drug classes. In this study, we presented the first WGS analysis of C. auris from Bangladesh, describing its origins, transmission dynamics, and antifungal susceptibility testing (AFST) profile. Ten C. auris isolates collected from hospital settings in Bangladesh were initially identified by CHROMagar Candida Plus, followed by VITEK2 system, and later sequenced using Illumina NextSeq 550 system. Reference-based phylogenetic analysis and variant calling pipelines were used to classify the isolates in different clades. All isolates aligned ~90% with the Clade I C. auris B11205 reference genome. Of the 10 isolates, 8 were clustered with Clade I isolates, highlighting a South Asian lineage prevalent in Bangladesh. Remarkably, the remaining two isolates formed a distinct cluster, exhibiting >42,447 single-nucleotide polymorphism differences compared to their closest Clade IV counterparts. This significant variation corroborates the emergence of a sixth clade (Clade VI) of C. auris in Bangladesh, with potential for international transmission. AFST results showed that 80% of the C. auris isolates were resistant to fluconazole and voriconazole, whereas Clade VI isolates were susceptible to azoles, echinocandins, and pyrimidine analogue. Genomic sequencing revealed ERG11_Y132F mutation conferring azole resistance while FCY1_S70R mutation found inconsequential in describing 5-flucytosine resistance. Our study underscores the pressing need for comprehensive genomic surveillance in Bangladesh to better understand the emergence, transmission dynamics, and resistance profiles of C. auris infections. Unveiling the discovery of a sixth clade (Clade VI) accentuates the indispensable role of advanced sequencing methodologies.IMPORTANCECandida auris is a nosocomial fungal pathogen that is commonly misidentified as other Candida species. Since its emergence in 2009, this multidrug-resistant fungus has become one of the five urgent antimicrobial threats by 2019. Whole-genome sequencing (WGS) has proven to be the most accurate identification technique of C. auris which also played a crucial role in the initial discovery of this pathogen. WGS analysis of C. auris has revealed five distinct clades where isolates of each clade differ among themselves based on pathogenicity, colonization, infection mechanism, as well as other phenotypic characteristics. In Bangladesh, C. auris was first reported in 2019 from clinical samples of a large hospital in Dhaka city. To understand the origin, transmission dynamics, and antifungal-resistance profile of C. auris isolates circulating in Bangladesh, we conducted a WGS-based surveillance study on two of the largest hospital settings in Dhaka, Bangladesh.

19.
Front Pharmacol ; 15: 1400105, 2024.
Article in English | MEDLINE | ID: mdl-38831882

ABSTRACT

Candida albicans: (C. albicans) is a prevalent opportunistic pathogen that can cause severe mucosal and systemic fungal infections, leading to high morbidity and mortality rates. Traditional chemical drug treatments for C. albicans infection have limitations, including the potential for the development of drug resistance. Essential oils, which are secondary metabolites extracted from plants, have gained significant attention due to their antibacterial activity and intestinal regulatory effects. It makes them an ideal focus for eco-friendly antifungal research. This review was aimed to comprehensively evaluate the research progress, mechanisms, and clinical application prospects of essential oils in treating C. albicans infections through their antibacterial and intestinal regulatory effects. We delve into how essential oils exert antibacterial effects against C. albicans infections through these effects and provide a comprehensive analysis of related experimental studies and clinical trials. Additionally, we offer insights into the future application prospects of essential oils in antifungal therapy, aiming to provide new ideas and methods for the development of safer and more effective antifungal drugs. Through a systematic literature review and data analysis, we hope to provide insights supporting the application of essential oils in antifungal therapy while also contributing to the research and development of natural medicines. In the face of increasingly severe fungal infections, essential oils might emerge as a potent method in our arsenal, aiding in the effective protection of human and animal health.

20.
Front Oral Health ; 5: 1408255, 2024.
Article in English | MEDLINE | ID: mdl-38872986

ABSTRACT

In a murine model (LCΔMHC-II) designed to abolish MHC-II expression in Langerhans cells (LCs), ∼18% of oral LCs retain MHC-II, yet oral mucosal CD4 T cells numbers are unaffected. In LCΔMHC-II mice, we now show that oral intraepithelial conventional CD8αß T cell numbers expand 30-fold. Antibody-mediated ablation of CD4 T cells in wild-type mice also resulted in CD8αß T cell expansion in the oral mucosa. Therefore, we hypothesize that MHC class II molecules uniquely expressed on Langerhans cells mediate the suppression of intraepithelial resident-memory CD8 T cell numbers via a CD4 T cell-dependent mechanism. The expanded oral CD8 T cells co-expressed CD69 and CD103 and the majority produced IL-17A [CD8 T cytotoxic (Tc)17 cells] with a minority expressing IFN-γ (Tc1 cells). These oral CD8 T cells showed broad T cell receptor Vß gene usage indicating responsiveness to diverse oral antigens. Generally supporting Tc17 cells, transforming growth factor-ß1 (TGF-ß1) increased 4-fold in the oral mucosa. Surprisingly, blocking TGF-ß1 signaling with the TGF-R1 kinase inhibitor, LY364947, did not reduce Tc17 or Tc1 numbers. Nonetheless, LY364947 increased γδ T cell numbers and decreased CD49a expression on Tc1 cells. Although IL-17A-expressing γδ T cells were reduced by 30%, LCΔMHC-II mice displayed greater resistance to Candida albicans in early stages of oral infection. These findings suggest that modulating MHC-II expression in oral LC may be an effective strategy against fungal infections at mucosal surfaces counteracted by IL-17A-dependent mechanisms.

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