scholarly journals Where the infection is isolated rather than the specific species correlates with adherence strength, whereas biofilm density remains static in clinically isolated Candida and arthroconidial yeasts

2021 ◽  
pp. 1-9
Author(s):  
Mei ElGindi ◽  
Rula Al-Baghdadi ◽  
Alex B. Jackman ◽  
Angelina S. Antonyan ◽  
Diana L. McMahon ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Fungi ◽  
Host Responses ◽  
Clinical Samples ◽  
Specific Species ◽  
Systemic Infections ◽  
First Time ◽  
Implanted Devices ◽  
Adherence Strength

To colonize and infect the host, arthroconidial yeasts must avoid being killed by the host’s defenses. The formation of biofilms on implanted devices allows fungi to avoid host responses and to disseminate into the host. To better study the mechanisms of infection by arthroconidial yeasts, adherence and biofilm formation were assayed using patient samples collected over 10 years. In clinical samples, adherence varies within species, but the relative adherence is constant for those samples isolated from the same infection site. Herein we document, for the first time, in-vitro biofilm formation by Trichosporon dohaense, T. ovoides, T. japonicum, T. coremiiforme, Cutaneotrichosporon mucoides, Cutaneotrichosporon cutaneum, Galactomyces candidus, and Magnusiomyces capitatus on clinically relevant catheter material. Analysis of biofilm biomass assays indicated that biofilm mass changes less than 2-fold, regardless of the species. Our results support the hypothesis that most pathogenic fungi can form biofilms, and that biofilm formation is a source of systemic infections.

scholarly journals Candida albicans forms biofilms on the vaginal mucosa

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3635-3644 ◽  
Author(s):  
M. M. Harriott ◽  
E. A. Lilly ◽  
T. E. Rodriguez ◽  
P. L. Fidel ◽  
M. C. Noverr
Keyword(s):  
Biofilm Formation ◽  
Ex Vivo ◽  
Microscopic Analysis ◽  
Vaginal Mucosa ◽  
First Time ◽  
Established Role ◽  
Type Strains

Current understanding of resistance and susceptibility to vulvovaginal candidiasis challenges existing paradigms of host defence against fungal infection. While abiotic biofilm formation has a clearly established role during systemic Candida infections, it is not known whether C. albicans forms biofilms on the vaginal mucosa and the possible role of biofilms in disease. In vivo and ex vivo murine vaginitis models were employed to examine biofilm formation by scanning electron and confocal microscopy. C. albicans strains included 3153A (lab strain), DAY185 (parental control strain), and mutants defective in morphogenesis and/or biofilm formation in vitro (efg1/efg1 and bcr1/bcr1). Both 3153A and DAY815 formed biofilms on the vaginal mucosa in vivo and ex vivo as indicated by high fungal burden and microscopic analysis demonstrating typical biofilm architecture and presence of extracellular matrix (ECM) co-localized with the presence of fungi. In contrast, efg1/efg1 and bcr1/bcr1 mutant strains exhibited weak or no biofilm formation/ECM production in both models compared to wild-type strains and complemented mutants despite comparable colonization levels. These data show for the first time that C. albicans forms biofilms in vivo on vaginal epithelium, and that in vivo biotic biofilm formation requires regulators of biofilm formation (BCR1) and morphogenesis (EFG1).

scholarly journals Deep assessment of human disease-associated ribosomal RNA modifications using Nanopore direct RNA sequencing

2021 ◽  
Author(s):  
Isabel S Naarmann-de Vries ◽  
Christiane Zorbas ◽  
Amina Lemsara ◽  
Maja Bencun ◽  
Sarah Schudy ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Clinical Samples ◽  
Sequencing Data ◽  
Rna Modifications ◽  
Flow Cells ◽  
Wide Range ◽  
Catalytically Active ◽  
Induced Pluripotent ◽  
First Time

The catalytically active component of ribosomes, rRNA, is long studied and heavily modified. However, little is known about functional and pathological consequences of changes in human rRNA modification status. Direct RNA sequencing on the Nanopore platform enables the direct assessment of rRNA modifications. We established a targeted Nanopore direct rRNA sequencing approach and applied it to CRISPR-Cas9 engineered HCT116 cells, lacking specific enzymatic activities required to establish defined rRNA base modifications. We analyzed these sequencing data along with wild type samples and in vitro transcribed reference sequences to specifically detect changes in modification status. We show for the first time that direct RNA-sequencing is feasible on smaller, i.e. Flongle, flow cells. Our targeted approach reduces RNA input requirements, making it accessible to the analysis of limited samples such as patient derived material. The analysis of rRNA modifications during cardiomyocyte differentiation of human induced pluripotent stem cells, and of heart biopsies from cardiomyopathy patients revealed altered modifications of specific sites, among them pseudouridine, 2-O-methylation of ribose and acetylation of cytidine. Targeted direct rRNA-seq analysis with JACUSA2 opens up the possibility to analyze dynamic changes in rRNA modifications in a wide range of biological and clinical samples.

scholarly journals Steroidal Glycosides from the Seeds of Hyoscyamus Niger L. and their Antifungal Activity

2007 ◽  
Vol 2 (1) ◽  
pp. 108-113
Author(s):  
Irina Lunga ◽  
Pavel Chintea ◽  
Stepan Shvets ◽  
Anna Favelb ◽  
Cosimo Pizza
Keyword(s):  
Nmr Spectroscopy ◽  
Antifungal Activity ◽  
Pathogenic Fungi ◽  
Phytochemical Analysis ◽  
Two Dimensional ◽  
Hyoscyamus Niger ◽  
Steroidal Glycosides ◽  
Spirostanol Saponins ◽  
First Time

Phytochemical analysis of the seeds of Hyocyamus niger L. (Solonaceae) resulted in the isolation of six steroidal glycosides, two furostanol (1, 2) and four spirostanol saponins (3, 4, 5, 6), which were found in this plant for the first time. The structures of these compounds were determined by detailed analysis of their spectral data, including two-dimensional NMR spectroscopy and MS spectroscopy. The antifungal activity of a crude steroidal glycoside extract, fractions of spirostanoles and individual glicosides was investigated in vitro against a panel of human pathogenic fungi, yeasts as well as dermatophytes and filamentous species.

scholarly journals Recurrent Vulvovaginal Candidiasis; a dynamic interkingdom biofilm disease of Candida and Lactobacillus

2021 ◽  
Author(s):  
Emily McKloud ◽  
Leighann Sherry ◽  
Ryan Kean ◽  
Christopher Delaney ◽  
Shanice Williams ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Treatment Options ◽  
Vulvovaginal Candidiasis ◽  
Clinical Samples ◽  
Vaginal Microbiome ◽  
Sequencing Technology ◽  
High Prevalence ◽  
Rrna Sequencing ◽  
Specific Health

AbstractVulvovaginal Candidiasis (VVC) is the most prevalent Candida infection in humans affecting 75% of women at least once throughout their lifetime. In its debilitating recurrent form, RVVC is estimated to affect 140 million women annually. Despite this strikingly high prevalence, treatment options for RVVC remain limited with many women experiencing failed clinical treatment with frontline azoles. Further, the cause of onset and recurrence of disease is largely unknown with few studies identifying potential mechanisms of failed treatment. This study aimed to assess a panel of clinical samples from healthy women and those with RVVC to investigate the influence of Candida, vaginal microbiome and antagonism between Candida and Lactobacillus on disease pathology. 16S rRNA sequencing characterised disease by a reduction in specific health-associated Lactobacillus such as L. crispatus, coupled with an increase in L. iners. In vitro analysis showed Candida albicans clinical isolates are capable of heterogeneous biofilm formation and show the presence of hyphae and C. albicans aggregates in vaginal lavage. Additionally, the ability of Lactobacillus to inhibit C. albicans biofilm formation and biofilm-related gene expression was demonstrated. Using RNA sequencing technology, we were able to exploit a possible mechanism by which L. crispatus may aim to re-establish a healthy vaginal environment through amino-acid acquisition from C. albicans. This study suggests RVVC is not entirely due to an arbitrary switch in C. albicans from commensal to pathogen and understanding interactions between the yeast and vaginal Lactobacillus species may be more crucial to elucidating the cause of RVVC and developing appropriate therapies.

scholarly journals In VitroAntifungal Susceptibility of Candida glabrata to Caspofungin and the Presence ofFKSMutations Correlate with Treatment Response in an Immunocompromised Murine Model of Invasive Infection

2014 ◽  
Vol 58 (7) ◽  
pp. 3646-3649 ◽  
Author(s):  
Fabiola Fernández-Silva ◽  
Michaela Lackner ◽  
Javier Capilla ◽  
Emilio Mayayo ◽  
Deanna Sutton ◽  
...  
Keyword(s):  
Murine Model ◽  
Hot Spot ◽  
Drug Efficacy ◽  
Invasive Infection ◽  
Content Type ◽  
Wide Range ◽  
Systemic Infections ◽  
First Time

ABSTRACTIt has been argued that thein vitroactivity of caspofungin (CSP) is not a good predictor of the outcome of echinocandin treatmentin vivo. We evaluated thein vitroactivity of CSP and the presence ofFKSmutations in the hot spot 1 (HS1) region of theFKS1andFKS2genes in 17 Candida glabratastrains with a wide range of MICs. The efficacy of CSP against systemic infections from each of the 17 strains was evaluated in a murine model. No HS1 mutations were found in the eight strains showing MICs for CSP of ≤0.5 μg/ml, but they were present in eight of the nine strains with MICs of ≥1 μg/ml, i.e., three in theFKS1gene and five in theFKS2gene. CSP was effective for treating mice infected with strains with MICs of ≤0.5 μg/ml, showed variable efficacy in animals challenged with strains with MICs of 1 μg/ml, and did not work in those with strains with MICs of >1 μg/ml. In addition, mutations, including one reported for the first time, were found outside the HS1 region in theFKS2gene of six strains with different MICs, but their presence did not influence drug efficacy. Thein vitroactivity of CSP was compared with that of another echinocandin, anidulafungin, suggesting that the MICs of both drugs, as well as mutations in the HS1 regions of theFKS1andFKS2genes, are predictive of outcome.

scholarly journals Assessment of Biofilm Formation among the Clinical Isolates of Escherichia coli in a Tertiary Care Hospital

2020 ◽  
pp. 26-32
Author(s):  
Bedobroto Biswas ◽  
Naik Shalini Ashok ◽  
Deepesh Nagarajan ◽  
Md Zaffar Iqubal
Keyword(s):  
Escherichia Coli ◽  
Tissue Culture ◽  
Biofilm Formation ◽  
Tertiary Care ◽  
Clinical Samples ◽  
Care Hospital ◽  
Plate Method ◽  
Culture Plate ◽  
Tissue Culture Plate

Aims: Identification and grading of the Escherichia coli according to their biofilm production capability. Study Design:  Cross-sectional study. Place and Duration of Study: This was conducted in Department Microbiology at M.S. Ramaiah Medical college and Hospital, Bengaluru from March 2017 to August 2017. Methodology: A total of 55 non repetitive Escherichia coli isolates were identified from various clinical samples like urine, pus ,tissue and peritoneal fluids .All the organisms were isolated in pure culture and biofilm formation was detected in vitro by Gold standard TCP (Tissue culture plate) method. Organisms were incubated for an extended period of 48 hours and the biofilms were detected by acetone alcohol elution method. Organisms were categorized as strong, moderate, weak and no biofilm producers based on the obtained OD value of the elute. Results: Majority of the isolates of Escherichia coli were obtained from catheterized urine culture (67.03%) followed by pus (25.50%).Most of the isolates were capable of forming biofilm in vitro by tissue culture plate method except a few (9.1%). 40% of the isolates were strong biofilm formers which had >4 ODC. 25.5% showed medium biofilm-forming capability and rest 25.5% showed weak biofilm formations in vitro. Conclusion: The ability to form biofilm from a species can give us a better understanding of the biofilm-related infections pertaining to the particular group. Detection of biofilms remains a most important determinant to approximate the incidence of such infections. Categorization of organisms according to their biofilm formation may help us understand the frequency of biofilm-associated infections, and thus take necessary precautions to avoid the problem. Further studies involving the detection of biofilm may be conducted and the tests can be implemented in routine diagnostic microbiology to assess the usefulness of the methods in detection of biofilm-related infections.

scholarly journals Biofilm Formation on Tracheostomy Tubes

2002 ◽  
Vol 81 (9) ◽  
pp. 659-661 ◽  
Author(s):  
William A. Jarrett ◽  
Julie Ribes ◽  
Jose M. Manaligod
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Bacterial Biofilms ◽  
Specific Material ◽  
Tracheostomy Tubes ◽  
Implanted Devices ◽  
Scanning Electron

An increased awareness of biofilms and their mechanisms has led to a better understanding of bacterial infections that occur following the placement of tracheostomy tubes and other implanted devices and prostheses. One aspect of biofilm formation that is still subject to debate is whether the specific material that is used to manufacture a tube has any bearing in the incidence of infection. We conducted a test of four different tube materials—polyvinyl chloride, silicone, stainless steel, and sterling silver—to ascertain how bacterial biofilms form on tracheostomy tubes and to determine if there is a material-dependent difference in biofilm formation. Scanning electron microscopy demonstrated that Pseudomonas aeruginosa and Staphylococcus epidermidis both formed bacterial biofilms on tracheostomy tubes in vitro. We also found that there was no difference in susceptibility to biofilm formation among the four tube materials tested.

Vesicular Lipid Nanoparticles (Liposomes) for the Treatment of Medical Device Infections

2011 ◽  
Vol 1316 ◽  
Author(s):  
Erik Taylor ◽  
Anubhav Kaviratna ◽  
Rinti Banerjee ◽  
Thomas J. Webster
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Lipid Nanoparticles ◽  
In Vitro Assay ◽  
Silver Sulfadiazine ◽  
Human Pathogens ◽  
Vitro Assay ◽  
First Time ◽  
Better Than

AbstractLiposomes (a phospholipid bi-layer which can be formulated to contain drugs or other reagents) composed of endogenous phospholipid dipalmitoylphosphatidylcholine (DPPC) in combination with dioleoylphosphatidylethanolamine (DOPE), lauric acid, and silver sulfadiazine were made into vesicular nanoparticles in this study using an optimized extrusion technique. Liposomes were then tested for antibacterial activity against a range of bacteria species including Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Bacillus subtilis (all are relevant human pathogens known to infect implants) and were also challenged to prevent the growth of adherent biofilms (a robust slimy extracellular matrix) through an in vitro assay relevant to device related infections. It was found that all liposomes reduced bacterial growth, and, most importantly, liposomes containing DPPC and DOPE reduced biofilm formation better than the commercially available antibiotic silver sulfadiazine. These results indicated for the first time that such liposomes might be a better approach to prevent device related infections.

scholarly journals In Vitro Evaluation of Antibacterial and Antifungal Activity of Biogenic Silver and Copper Nanoparticles: The First Report of Applying Biogenic Nanoparticles against Pilidium concavum and Pestalotia sp. Fungi

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5402
Author(s):  
Maryam Bayat ◽  
Meisam Zargar ◽  
Elena Chudinova ◽  
Tamara Astarkhanova ◽  
Elena Pakina
Keyword(s):  
Antifungal Activity ◽  
Copper Nanoparticles ◽  
Metallic Nanoparticles ◽  
Pathogenic Fungi ◽  
Synthesis Of Nanoparticles ◽  
Chemical Residues ◽  
Antibacterial And Antifungal ◽  
First Time ◽  
Synthesis Approach

There is increased attention paid to metallic nanoparticles due to their intensive use in various branches of agriculture and biotechnology, such as pest management, nanosensors, gene delivery, seed treatment, etc. There has been growing interest in applying environmentally friendly strategies for synthesizing nanoparticles without using substances which are hazardous to the environment. Biological practices for the synthesis of nanoparticles have been considered as possible ecofriendly alternatives to chemical synthesis. In the present study, we used biogenic silver and copper nanoparticles which were prepared by a previously reported green method. Moreover, the problem of chemical residues, which usually remain along with chemically synthesized nanoparticles and limit their application, was solved by developing such a green synthesis approach. To study the antibacterial activity of silver and copper nanoparticles, Pseudomonas aeruginosa was used; for the evaluation of antifungal activity, the pathogenic fungi Botrytis cinerea, Pilidium concavum and Pestalotia sp. were applied. To the best of our knowledge, this study represents the first time that the antifungal impact of a nanoparticle has been tested on Pilidium concavum and Pestalotia sp. Silver nanoparticles were found to be the more effective antimicrobial agent against all examined pathogens in comparison to copper nanoparticles. Data from such investigations provide valuable preliminary data on silver nanoparticle-based compounds or composites for use in the management of different pathogens.

scholarly journals In Silico Modeling of Biofilm Formation by Nontypeable Haemophilus influenzae In Vivo

mSphere ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Jonathan R. Brown ◽  
Joseph Jurcisek ◽  
Vinal Lakhani ◽  
Ali Snedden ◽  
William C. Ray ◽  
...  
Keyword(s):  
Haemophilus Influenzae ◽  
In Silico ◽  
Biofilm Formation ◽  
Host Responses ◽  
Model Parameters ◽  
Agent Based Model ◽  
Content Type ◽  
Agent Based

ABSTRACT Biofilms formed by nontypeable Haemophilus influenzae (NTHI) bacteria play an important role in multiple respiratory tract diseases. Visual inspection of the morphology of biofilms formed during chronic infections shows distinct differences from biofilms formed in vitro. To better understand these differences, we analyzed images of NTHI biofilms formed in the middle ears of Chinchilla lanigera and developed an in silico agent-based model of the formation of NTHI biofilms in vivo. We found that, as in vitro, NTHI bacteria are organized in self-similar patterns; however, the sizes of NTHI clusters in vivo are more than 10-fold smaller than their in vitro counterparts. The agent-based model reproduced these patterns and suggested that smaller clusters occur due to elimination of planktonic NTHI cells by the host responses. Estimation of model parameters by fitting simulation results to imaging data showed that the effects of several processes in the model change during the course of the infection. IMPORTANCE Multiple respiratory illnesses are associated with formation of biofilms within the human airway by NTHI. However, a substantial amount of our understanding of the mechanisms that underlie NTHI biofilm formation is obtained from in vitro studies. Our in silico model that describes biofilm formation by NTHI within the middle ears of Chinchilla lanigera will help isolate processes potentially responsible for the differences between the morphologies of biofilms formed in vivo versus those formed in vitro. Thus, the in silico model can be used to glean mechanisms that underlie biofilm formation in vivo and connect those mechanisms to those obtained from in vitro experiments. The in silico model developed here can be extended to investigate potential roles of specific host responses (e.g., mucociliary clearance) on NTHI biofilm formation in vivo. The developed computational tools can also be used to analyze and describe biofilm formation by other bacterial species in vivo.

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