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1.
Health Policy Open ; 6: 100122, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38779080

ABSTRACT

Background: Socioeconomic conditions are strongly associated with breast and cervical cancer incidence and mortality patterns; therefore, social protection programmes (SPPs) might impact these cancers. This study aimed to evaluate the effect of SPPs on breast and cervical cancer outcomes and their risk/protective factors. Methods: Five databases were searched for articles that assessed participation in PPS and the incidence, survival, mortality (primary outcomes), screening, staging at diagnosis and risk/protective factors (secondary outcomes) for these cancers. Only peer-reviewed quantitative studies of women receiving SPPs compared to eligible women not receiving benefits were included. Independent reviewers selected articles, assessed eligibility, extracted data, and assessed the risk of bias. A harvest plot represents the included studies and shows the direction of effect, sample size and risk of bias. Findings: Of 17,080 documents retrieved, 43 studies were included in the review. No studies evaluated the primary outcomes. They all examined the relationship between SPPs and screening, as well as risk and protective factors. The harvest plot showed that in lower risk of bias studies, participants of SPPs had lower weight and fertility, were older at sexual debut, and breastfed their infants for longer. Interpretation: No studies have yet assessed the effect of SPPs on breast and cervical cancer incidence, survival, or mortality; nevertheless, the existing evidence suggests positive impacts on risk and protective factors.

2.
Eur J Clin Microbiol Infect Dis ; 43(3): 605-610, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38112967

ABSTRACT

FASTinov® developed a rapid antimicrobial susceptibility test that includes the purification of a bacterial suspension directly from positive blood cultures (BC). In order to streamline laboratory workflow, the use of the bacterial suspension obtained through FASTinov® sample prep was tested for identification (ID) by matrix absorption laser deionization-time of flight mass spectrometry (MALDI-TOF MS) (Bruker) in 364 positive BC, and its accuracy assessed comparing with the MALDI-TOF MS ID of the next-day subcultured colonies. FASTinov sample prep was highly reliable for rapid ID directly from BC with proportion of agreement of 94.9% for Gram-positive and 96.3% for Gram-negative bacteria.


Subject(s)
Bacteremia , Blood Culture , Humans , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Bacteria , Gram-Negative Bacteria , Laboratories , Bacteremia/microbiology
3.
Commun Biol ; 5(1): 1118, 2022 10 21.
Article in English | MEDLINE | ID: mdl-36271293

ABSTRACT

The increasing prevalence of candidosis caused by Candida glabrata is related to its ability to acquire azole resistance. Although azole resistance mechanisms are well known, the mechanisms for azole import into fungal cells have remained obscure. In this work, we have characterized two hexose transporters in C. glabrata and further investigate their role as potential azole importers. Three azole susceptible C. glabrata clinical isolates were evolved towards azole resistance and the acquired resistance phenotype was found to be independent of CgPDR1 or CgERG11 mutations. Through whole-genome sequencing, CgHXT4/6/7 was found to be mutated in the three evolved strains, when compared to their susceptible parents. CgHxt4/6/7 and the 96% identical CgHxt6/7 were found to confer azole susceptibility and increase azole accumulation in C. glabrata cells, strikingly rescuing the susceptibility phenotype imposed by CgPDR1 deletion, while the identified loss-of-function mutation in CgHXT4/6/7, leads to increased azole resistance. In silico docking analysis shows that azoles display a strong predicted affinity for the glucose binding site of CgHxt4/6/7. Altogether, we hypothesize that hexose transporters, such as CgHxt4/6/7 and CgHxt6/7, may constitute a family of azole importers, involved in clinical drug resistance in fungal pathogens, and constituting promising targets for improved antifungal therapy.


Subject(s)
Azoles , Candida glabrata , Candida glabrata/genetics , Azoles/pharmacology , Azoles/therapeutic use , Drug Resistance, Fungal/genetics , Antifungal Agents/pharmacology , Glucose , Evolution, Molecular , Hexoses
4.
Antibiotics (Basel) ; 11(8)2022 Aug 19.
Article in English | MEDLINE | ID: mdl-36009999

ABSTRACT

Plasmidic AmpC (pAmpC) enzymes are responsible for the hydrolysis of extended-spectrum cephalosporins but they are not routinely investigated in many clinical laboratories. Phenotypic assays, currently the reference methods, are cumbersome and culture dependent. These methods compare the activity of cephalosporins with and without class C inhibitors and the results are provided in 24-48 h. Detection by molecular methods is quicker, but several genes should be investigated. A new assay for the rapid phenotypic detection of pAmpC enzymes of the Enterobacterales group-I (not usually AmpC producers) based on flow cytometry technology was developed and validated. The technology was evaluated in two sites: FASTinov, a spin-off of Porto University (Portugal) where the technology was developed, and the Microbiology Department of Ramón y Cajal University Hospital in Madrid (Spain). A total of 100 strains were phenotypically screened by disk diffusion for the pAmpC with the new 2 h assay. Molecular detection of the pAmpC genes was also performed on discrepant results. Forty-two percent of the strains were phenotypically classified as pAmpC producers using disk diffusion. The percentage of agreement of the flow cytometric assay was 93.0%, with 95.5% sensitivity and 91.1% specificity. Our proposed rapid assay based on flow cytometry technology can, in two hours, accurately detect pAmpC enzymes.

5.
J Clin Microbiol ; 59(10): e0054421, 2021 09 20.
Article in English | MEDLINE | ID: mdl-34346718

ABSTRACT

The FASTinov flow cytometry kit, an ultrarapid antimicrobial susceptibility test, was directly evaluated on positive blood cultures (BC) at two sites: (i) FASTinov, S.A., in Porto, Portugal, using BC spiked with well-characterized bacteria, and (ii) Ramón y Cajal University Hospital in Madrid, Spain, using positive BC from patients. Two kits were evaluated, FASTgramneg (Enterobacterales, Pseudomonas, Acinetobacter) and FASTgrampos (Staphylococcus, Enterococcus). Dedicated software for cytometric data analysis and interpretative reporting, including both CLSI and EUCAST criteria, was used. The FASTgramneg kit also provides information about the presence of resistant mechanisms, including extended-spectrum beta-lactamases (ESBLs) and carbapenemases. After 1 h of incubation at 37°C, bacteria were analyzed using a CytoFLEX cytometer (Beckman, CA). Disk diffusion was performed as the reference susceptibility method. Overall, 447 positive BC were included, 100 from hospitalized patients. Categorical agreement values for the FASTgramneg panel were 96.8% based on EUCAST criteria and 96.4% based on CLSI criteria. For the FASTgrampos panel, categorical agreement was 98.6% when using both criteria. When EUCAST criteria were used, the percentages of errors for the FASTgramneg panel were 2.1% minor errors (mE), 1.3% major errors (ME), and 0.6% very major errors (VME). When CLSI criteria were used, 2.9% mE, 0.9% ME, and 0.4% VME were found. VME were mainly observed with amoxicillin-clavulanate, cefotaxime, ceftazidime, and gentamicin. The FASTgrampos panel showed 0.3% mE, 1.4% ME, and 0.4% VME when EUCAST criteria were used (VME with respect to gentamicin and Staphylococcus) and 0.4% mE, 1.4% ME, and no VME when CLSI criteria were used. The FASTinov flow cytometry kits represent a rapid alternative for direct antimicrobial susceptibility testing from positive BC, showing time to results of <2 h, and can be used to personalize antibiotic and stewardship practices.


Subject(s)
Anti-Bacterial Agents , Blood Culture , Anti-Bacterial Agents/pharmacology , Bacteria , Flow Cytometry , Humans , Microbial Sensitivity Tests
6.
Clin Microbiol Infect ; 26(11): 1559.e1-1559.e4, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32835792

ABSTRACT

OBJECTIVES: Both EUCAST and CLSI recommend broth microdilution for antimicrobial susceptibility testing of colistin, but this method is cumbersome and takes 16-24 h to give results. Our objective was to evaluate a rapid quantitative colistin MIC susceptibility assay based on flow cytometry analysis (FASTcolistin MIC) in comparison with standard broth microdilution assay. METHODS: One hundred and sixteen Gram-negative bacilli (78 Enterobacterales, 28 Pseudomonas aeruginosa and 10 Acinetobacter baumannii) were studied in parallel using standard broth microdilution following EUCAST recommendations and FASTcolistin MIC kit. In the last one, a bacteria suspension (0.5 MacFarland) was prepared, diluted in Muller-Hinton broth, incubated in the susceptibility panel containing different colistin concentrations (range 0.125-64 mg/L) with a fluorescent probe and incubated 1 h at 35ºC. After that, a flow cytometry analysis using CytoFLEX (Beckmam) was performed. Using a dedicated software (BioFAST) an automated MIC result was obtained after 1.5 h. Performance evaluation was performed according to the ISO standard 20776-2. Reproducibility and repeatability, categorical (CA) and essential agreement (EA), and lot-to-lot variation and operator-to-operator variability, as well as time to results were determined. RESULTS: Overall, 100% CA (CI 97-100%) and 95.7% EA (CI 90-98%) was obtained with high repeatability (100%; CI 80-100%)and reproducibility (97%; (CI 83-99%)). Absence of lot-to-lot variations or differences in the operators' performance was observed. CONCLUSIONS: FASTcolistin MIC is an accurate, reliable and ultra-rapid method (1 h incubation versus 24 h) for susceptibility testing of colistin of common Gram-negative bacilli recovered in clinical laboratories.


Subject(s)
Acinetobacter baumannii/drug effects , Colistin/pharmacology , Enterobacteriaceae/drug effects , Pseudomonas aeruginosa/drug effects , Flow Cytometry , Microbial Sensitivity Tests , Reproducibility of Results , Time Factors
7.
Eur J Clin Microbiol Infect Dis ; 39(10): 1907-1914, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32483685

ABSTRACT

The urgent need for rapid antimicrobial susceptibility is broadly apparent from government reports to the lay press. Accordingly, we developed a flow-cytometry assay (FCM) for evaluating ceftolozane-tazobactam (C/T) susceptibility directly on blood cultures (BC) requiring < 2 h from flag positivity to report. The protocol was optimized with C/T-susceptible and C/T-resistant gram-negative bacilli inoculated in BC aerobic bottles (Becton-Dickinson, USA), and afterward optimized for different C/T concentrations (1/4, 2/4, 4/4, and 8/4 mg/L) for 1 h incubation (37 °C), followed by FCM and software analysis. Fluorescent membrane permeability and membrane potential dyes were comparatively used to detect early cell lesions using the CytoFLEX cytometer (Beckman-Coulter, USA). Repeatability, reproducibility, and stability of the assay up to 48 h after BC positivity were determined. Internal validation was performed in spiked BC bottles with 130 Enterobacterales and 32 Pseudomonas aeruginosa isolates from Porto University (Portugal), including 13 ATCC isolates. Additionally, 64 gram-negative bacilli recovered from positive BC at Ramon y Cajal Hospital (Madrid, Spain) were tested. Categorical agreement (CA) and analytical errors were calculated comparing FCM with broth microdilution results. Only the membrane potential dyes clearly distinguished CT-susceptible and CT-resistant isolates. Excellent repeatability, reproducibility, and inter-method concordance was observed. Overall, CA was 99.1% using EUCAST criteria with 2 major errors and 98.7% with CLSI criteria with 2 major and 1 minor errors. A new, accurate, and ultra-rapid FCM (< 2 h) for testing C/T susceptibility gave accurate results and would expand current FCM antimicrobial susceptibility assay.


Subject(s)
Gram-Negative Bacteria/isolation & purification , Gram-Negative Bacterial Infections/diagnosis , Gram-Positive Bacteria/isolation & purification , Gram-Positive Bacterial Infections/diagnosis , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Blood Culture , Cephalosporins/pharmacology , Cephalosporins/therapeutic use , Flow Cytometry , Gram-Negative Bacteria/drug effects , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/microbiology , Gram-Positive Bacteria/drug effects , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/microbiology , Humans , Portugal , Spain , Tazobactam/pharmacology , Tazobactam/therapeutic use
8.
Article in English | MEDLINE | ID: mdl-30348666

ABSTRACT

Candida glabrata is an emerging fungal pathogen. Its increased prevalence is associated with its ability to rapidly develop antifungal drug resistance, particularly to azoles. In order to unravel new molecular mechanisms behind azole resistance, a transcriptomics analysis of the evolution of a C. glabrata clinical isolate (isolate 044) from azole susceptibility to posaconazole resistance (21st day), clotrimazole resistance (31st day), and fluconazole and voriconazole resistance (45th day), induced by longstanding incubation with fluconazole, was carried out. All the evolved strains were found to accumulate lower concentrations of azole drugs than the parental strain, while the ergosterol concentration remained mostly constant. However, only the population displaying resistance to all azoles was found to have a gain-of-function mutation in the C. glabrataPDR1 gene, leading to the upregulation of genes encoding multidrug resistance transporters. Intermediate strains, exhibiting posaconazole/clotrimazole resistance and increased fluconazole/voriconazole MIC levels, were found to display alternative ways to resist azole drugs. Particularly, posaconazole/clotrimazole resistance after 31 days was correlated with increased expression of adhesin genes. This finding led us to identify the Epa3 adhesin as a new determinant of azole resistance. Besides being required for biofilm formation, Epa3 expression was found to decrease the intracellular accumulation of azole antifungal drugs. Altogether, this work provides a glimpse of the transcriptomics evolution of a C. glabrata population toward multiazole resistance, highlighting the multifactorial nature of the acquisition of azole resistance and pointing out a new player in azole resistance.


Subject(s)
Antifungal Agents/pharmacology , Azoles/pharmacology , Candida glabrata/drug effects , Candida glabrata/genetics , Drug Resistance, Fungal/genetics , Candida glabrata/isolation & purification , Clotrimazole/pharmacology , Ergosterol/metabolism , Fluconazole/pharmacology , Gene Expression Regulation, Fungal/drug effects , Humans , Membrane Transport Proteins/genetics , Microbial Sensitivity Tests , Transcription Factors/genetics , Transcriptome/genetics , Triazoles/pharmacology , Voriconazole/pharmacology
9.
Front Microbiol ; 8: 2455, 2017.
Article in English | MEDLINE | ID: mdl-29312169

ABSTRACT

Laboratory assessment of antimicrobial susceptibility is a prerequisite for adequate management of infections. The aim of this research was to evaluate the performance of the novel FASTinov® kit for antimicrobial susceptibility testing (AST) of Gram negative bacilli directly on positive blood cultures. One hundred and two positive blood cultures from patients of a Portuguese University Hospital were included. AST were performed with routine method, Vitek2, with FASTinov® kit, and with the gold standard microdilution. Bacteria directly extracted from blood cultures were used to inoculate the FASTinov® kit. Time-to-result as well as the number of patients receiving initially inappropriate therapy (and those in whom de-escalation would have been done) and length of stay (LOS) was recorded. Seventy percent of patients were over 70 years old and 18.6% were admitted in intensive care units. Regarding the isolates, 88.2% were Enterobacteriaceae, 9.8% Pseudomonas spp. and 1% Acinetobacter spp. Extended spectrum ß-lactamases producing-Enterobacteriaceae were found in 7.8% of cases and 10.8% were multi-drug resistant. Fifty-one hours was the mean of time-to-result for routine test (Vitek2) vs. 2 h response regarding Fastinov® test. The overall agreement between FASTinov® and the reference microdilution method was 98%. According to the susceptibility phenotype, 16.7% of patients received initially inappropriate therapy and the mean hospital LOS of these patients was significantly higher. FASTinov® kit revealed an excellent correlation with the AST standard method and provided much earlier results than Vitek2.

10.
Front Microbiol ; 7: 526, 2016.
Article in English | MEDLINE | ID: mdl-27148215

ABSTRACT

For years, antifungal drug resistance in Candida species has been associated to the expression of ATP-Binding Cassette (ABC) multidrug transporters. More recently, a few drug efflux pumps from the Drug:H(+) Antiporter (DHA) family have also been shown to play a role in this process, although to date only the Candida albicans Mdr1 transporter has been demonstrated to be relevant in the clinical acquisition of antifungal drug resistance. This work provides evidence to suggest the involvement of the C. glabrata DHA transporters CgAqr1, CgQdr2, CgTpo1_1, and CgTpo3 in the clinical acquisition of clotrimazole drug resistance. A screening for azole drug resistance in 138 C. glabrata clinical isolates, from patients attending two major Hospitals in Portugal, was performed. Based on this screening, 10 clotrimazole susceptible and 10 clotrimazole resistant isolates were selected for further analysis. The transcript levels of CgAQR1, CgQDR2, CgTPO1_1, and CgTPO3 were found to be significantly up-regulated in resistant isolates when compared to the susceptible ones, with a level of correlation that was found to be similar to that of CgCDR2, an ABC gene known to be involved in the clinical acquisition of resistance. As a proof-of-concept experiment, the CgTPO3 gene was deleted in an azole resistant C. glabrata isolate, exhibiting high levels of expression of this gene. The deletion of CgTPO3 in this isolate was found to lead to decreased resistance to clotrimazole and fluconazole, and increased accumulation of azole drugs, thus suggesting the involvement of this transporter in the manifestation of azole resistance.

11.
Am J Hematol ; 91(6): 575-80, 2016 06.
Article in English | MEDLINE | ID: mdl-26955792

ABSTRACT

The multicenter retrospective study conducted in 38 centers from 20 countries including 172 adult patients with CNS MM aimed to describe the clinical and pathological characteristics and outcomes of patients with multiple myeloma (MM) involving the central nervous system (CNS). Univariate and multivariate analyses were performed to identify prognostic factors for survival. The median time from MM diagnosis to CNS MM diagnosis was 3 years. Thirty-eight patients (22%) were diagnosed with CNS involvement at the time of initial MM diagnosis and 134 (78%) at relapse/progression. Upon diagnosis of CNS MM, 97% patients received initial therapy for CNS disease, of which 76% received systemic therapy, 36% radiotherapy and 32% intrathecal therapy. After a median follow-up of 3.5 years, the median overall survival (OS) from the onset of CNS involvement for the entire group was 7 months. Untreated and treated patients had median OS of 2 and 8 months, respectively (P < 0.001). At least one previous line of therapy for MM before the diagnosis of CNS disease and >1 cytogenetic abnormality detected by FISH were independently associated with worse OS. The median OS for patients with 0, 1 and 2 of these risk factors were 25 months, 5.5 months and 2 months, respectively (P < 0.001). Neurological manifestations, not considered chemotherapy-related, observed at any time after initial diagnosis of MM should raise a suspicion of CNS involvement. Although prognosis is generally poor, the survival of previously untreated patients and patients with favorable cytogenetic profile might be prolonged due to systemic treatment and/or radiotherapy. Am. J. Hematol. 91:575-580, 2016. © 2016 Wiley Periodicals, Inc.


Subject(s)
Central Nervous System Neoplasms/diagnosis , Central Nervous System Neoplasms/mortality , Multiple Myeloma/mortality , Multiple Myeloma/therapy , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , Central Nervous System Neoplasms/secondary , Central Nervous System Neoplasms/therapy , Chromosome Aberrations , Combined Modality Therapy , Female , Humans , Male , Middle Aged , Multiple Myeloma/complications , Multiple Myeloma/pathology , Prognosis , Radiotherapy , Retrospective Studies , Survival Analysis , Survival Rate , Treatment Outcome
13.
Antimicrob Agents Chemother ; 59(10): 6629-33, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26248365

ABSTRACT

Candida parapsilosis is the second most prevalent fungal agent causing bloodstream infections. Nevertheless, there is little information about the molecular mechanisms underlying azole resistance in this species. Mutations (G1747A, A2619C, and A3191C) in the MRR1 transcription factor gene were identified in fluconazole- and voriconazole-resistant strains. Independent expression of MRR1 genes harboring these mutations showed that G1747A (G583R) and A2619C (K873N) are gain-of-function mutations responsible for azole resistance, the first described in C. parapsilosis.


Subject(s)
Fluconazole/pharmacology , Fungal Proteins/genetics , Transcription Factors/genetics , Voriconazole/pharmacology , Candida/drug effects , Candida/genetics , Drug Resistance, Fungal , Fungal Proteins/physiology , Gene Expression Regulation, Fungal/drug effects , Gene Expression Regulation, Fungal/genetics , Molecular Sequence Data , Mutation/genetics , Transcription Factors/physiology
14.
Antimicrob Agents Chemother ; 59(7): 4289-92, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25845879

ABSTRACT

Candida albicans is the most prevalent cause of fungemia worldwide. Its ability to develop resistance in patients receiving azole antifungal therapy is well documented. In a murine model of systemic infection, we show that ibuprofen potentiates fluconazole antifungal activity against a fluconazole-resistant strain, drastically reducing the fungal burden and morbidity. The therapeutic combination of fluconazole with ibuprofen may constitute a new approach for the management of antifungal therapeutics to reverse the resistance conferred by efflux pump overexpression.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Antifungal Agents/therapeutic use , Candidiasis/drug therapy , Fluconazole/therapeutic use , Ibuprofen/therapeutic use , Animals , Candida albicans/drug effects , Candida albicans/genetics , Candidiasis/microbiology , Drug Resistance, Fungal/genetics , Drug Synergism , Female , Fungal Proteins/genetics , Fungal Proteins/metabolism , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Mice , Mice, Inbred BALB C , Microbial Sensitivity Tests
15.
Front Microbiol ; 6: 205, 2015.
Article in English | MEDLINE | ID: mdl-25814989

ABSTRACT

We have performed the characterization of the adhesion profile, biofilm formation, cell surface hydrophobicity (CSH) and antifungal susceptibility of 184 Candida clinical isolates obtained from different human reservoirs. Adhesion was quantified using a flow cytometric assay and biofilm formation was evaluated using two methodologies: XTT and crystal violet assay. CSH was quantified with the microbial adhesion to hydrocarbons test while planktonic susceptibility was assessed accordingly the CLSI protocol for yeast M27-A3 S4. Yeast cells of non-albicans species exhibit increased ability to adhere and form biofilm. However, the correlation between adhesion and biofilm formation varied according to species and also with the methodology used for biofilm assessment. No association was found between strain's site of isolation or planktonic antifungal susceptibility and adhesion or biofilm formation. Finally CSH seemed to be a good predictor for biofilm formation but not for adhesion. Despite the marked variability registered intra and inter species, C. tropicalis and C. parapsilosis were the species exhibiting high adhesion profile. C. tropicalis, C. guilliermondii, and C. krusei revealed higher biofilm formation values in terms of biomass. C. parapsilosis was the species with lower biofilm metabolic activity.

16.
J Antimicrob Chemother ; 70(4): 1083-93, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25558078

ABSTRACT

OBJECTIVES: The objective of this study was to clarify the antifungal properties of cerium, a lanthanide member, against Candida species. A comprehensive study with planktonic and sessile cells was performed. The ability of cerium nitrate (CN) to impair in vitro and in vivo biofilm formation was evaluated and its potential use in biofilm treatment was also evaluated. METHODS: Forty-eight clinical isolates of different Candida species and the type strain ATCC 90028 were tested according to the protocol M27-A3. The MICs and minimum lethal concentrations were determined. A time-kill assay was performed and a cytometric kinetic study was performed using live/dead markers. Biofilm inhibition and biofilm susceptibility in the presence of cerium was evaluated by quantification of the biofilm metabolic activity and total biomass with XTT and crystal violet assays, respectively. CN in vivo efficacy as a coating for medical indwelling devices was evaluated for the first time for Candida parapsilosis, using a mouse subcutaneous foreign body model using polyurethane catheter segments. Scanning electron microscopy was used to assess biofilm architecture after CN treatment. RESULTS: The MICs for planktonic cells correlated with severe cellular metabolic activity impairment and membrane damage after 3 h of incubation. Moreover, CN efficiently prevented biofilm formation both in vitro and in vivo in segments of polyurethane catheters. At higher concentrations, it was also able to disorganize and almost eradicate preformed biofilms. CONCLUSIONS: Our results strongly suggest that CN application in the clinical setting might be effective in preventing the formation of biofilm-associated infections, namely through catheter coating and ultimately as an antimicrobial lock therapy.


Subject(s)
Antifungal Agents/pharmacology , Biofilms/drug effects , Candida/drug effects , Candida/physiology , Cerium/pharmacology , Animals , Candida/isolation & purification , Candidiasis/microbiology , Catheters/microbiology , Female , Foreign Bodies/microbiology , Gentian Violet/metabolism , Humans , Mice, Inbred BALB C , Microbial Sensitivity Tests , Microbial Viability/drug effects , Microscopy, Electron, Scanning , Staining and Labeling , Tetrazolium Salts/metabolism
17.
mBio ; 4(4)2013 Aug 30.
Article in English | MEDLINE | ID: mdl-23800396

ABSTRACT

UNLABELLED: In the human fungal pathogen Candida albicans, the CUG codon is translated 97% of the time as serine and 3% of the time as leucine, which potentially originates an array of proteins resulting from the translation of a single gene. Genes encoding cell surface proteins are enriched in CUG codons; thus, CUG mistranslation may influence the interactions of the organism with the host. To investigate this, we compared a C. albicans strain that misincorporates 28% of leucine at CUGs with a wild-type parental strain. The first strain displayed increased adherence to inert and host molecules. In addition, it was less susceptible to phagocytosis by murine macrophages, probably due to reduced exposure of cell surface ß-glucans. To prove that these phenotypes occurred due to serine/leucine exchange, the C. albicans adhesin and invasin ALS3 was expressed in Saccharomyces cerevisiae in its two natural isoforms (Als3p-Leu and Als3p-Ser). The cells with heterologous expression of Als3p-Leu showed increased adherence to host substrates and flocculation. We propose that CUG mistranslation has been maintained during the evolution of C. albicans due to its potential to generate cell surface variability, which significantly alters fungus-host interactions. IMPORTANCE: The translation of genetic information into proteins is a highly accurate cellular process. In the human fungal pathogen Candida albicans, a unique mistranslation event involving the CUG codon occurs. The CUG codon is mainly translated as serine but can also be translated as leucine. Leucine and serine are two biochemically distinct amino acids, hydrophobic and hydrophilic, respectively. The increased rate of leucine incorporation at CUG decoding triggers C. albicans virulence attributes, such as morphogenesis, phenotypic switching, and adhesion. Here, we show that CUG mistranslation masks the fungal cell wall molecule ß-glucan that is normally recognized by the host immune system, delaying its response. Furthermore, we demonstrate that two different proteins of the adhesin Als3 generated by CUG mistranslation confer increased hydrophobicity and adhesion ability on yeast cells. Thus, CUG mistranslation functions as a mechanism to create protein diversity with differential activities, constituting an advantage for a mainly asexual microorganism. This could explain its preservation during evolution.


Subject(s)
Antigenic Variation , Antigens, Fungal/biosynthesis , Candida albicans/immunology , Candida albicans/metabolism , Fungal Proteins/biosynthesis , Membrane Proteins/biosynthesis , Protein Biosynthesis , Animals , Cell Line , Fungal Proteins/genetics , Fungal Proteins/immunology , Fungal Proteins/metabolism , Host-Pathogen Interactions , Leucine/genetics , Leucine/metabolism , Macrophages/immunology , Macrophages/microbiology , Mice , Phagocytosis , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Recombinant Proteins/metabolism , Saccharomyces cerevisiae/genetics , Serine/genetics , Serine/metabolism
18.
FEMS Yeast Res ; 9(4): 626-33, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19385998

ABSTRACT

Candida parapsilosis is a common isolate from clinical fungal infectious episodes. Resistance of C. parapsilosis to azoles has been increasingly reported. To analyse the development of resistance in C. parapsilosis, four azole-susceptible clinical strains and one American Type Culture Collection type strain were cultured in the presence of fluconazole, voriconazole and posaconazole at different concentrations. The isolates developed variable degrees of azole resistance according to the antifungal used. Fluconazole was the fastest inducer while posaconazole was the slowest. Fluconazole and voriconazole induced resistance to themselves and each other, but not to posaconazole. Posaconazole induced resistance to all azoles. Developed resistance was stable; it could be confirmed after 30 days of subculture in drug-free medium. Azole-resistant isolates revealed a homogeneous population structure; the role of azole transporter efflux pumps was minor after evaluation by microdilution and cytometric assays with efflux pump blockers (verapamil, ibuprofen and carbonyl cyanide 3-chloro-phenylhydrazone). We conclude that the rapid development of azole resistance occurs by a mechanism that might involve mutation of genes responsible for ergosterol biosynthesis pathway, stressed by exposure to antifungals.


Subject(s)
Antifungal Agents/pharmacology , Candida/drug effects , Fluconazole/pharmacology , Pyrimidines/pharmacology , Triazoles/pharmacology , Biosynthetic Pathways/genetics , Drug Resistance, Fungal , Ergosterol/biosynthesis , Humans , Microbial Sensitivity Tests , Mutation , Voriconazole
19.
BMC Microbiol ; 8: 9, 2008 Jan 17.
Article in English | MEDLINE | ID: mdl-18201378

ABSTRACT

BACKGROUND: The administration of non-antifungal drugs during patient hospitalization might be responsible for discrepancies between in vitro and in vivo susceptibility to antifungals. Propofol is often administered to intensive care units as a sedative. The purpose of this study was to evaluate the effect of propofol lipidic infusion upon the growth and susceptibility profile of pathogenic fungi. Candida and Aspergillus were studied regarding the ability to grow and its susceptibility profile to antifungals in the presence of propofol infusion (Fresenius(R)) (1.25, 2.5 and 5 mg.ml-1) and its lipidic vehicle. The intensity of fluorescence after staining with FUN1, in the presence and absence of propofol infusion, was determined by flow cytometry. Radioactivity assays were also performed in order to quantify the input of [3H]- itraconazole into the fungal cell in the presence of propofol. Assays were repeated after addition of sodium azide, in order to block efflux pumps. RESULTS: Propofol infusion promoted budding of Candida and the germination of Aspergillus, latter forming a lipid layer around the hypha. An increase of minimal fungicidal concentrations regarding both Candida and Aspergillus strains was found for all antifungals when incubated simultaneously with propofol infusion. A decrease of the intensity of fluorescence of Candida cells was systematically observed, as well as a significant reduced intracellular uptake of [3H] itraconazole in cells treated with propofol infusion, even after the blockade of efflux pumps. The results obtained when testing with the lipid vehicle were similar. CONCLUSION: Propofol infusion, due to its lipidic vehicle, increased the fungal germination and promoted resistance to antifungals. This effect seems to be related to the reduced access and/or permeabilization to fungal cells by antifungals.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus/drug effects , Candida/drug effects , Flow Cytometry/methods , Itraconazole/metabolism , Propofol/pharmacokinetics , Drug Resistance, Fungal , Itraconazole/pharmacology , Lipids , Microbial Sensitivity Tests/methods , Propofol/pharmacology
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