scholarly journals Monitoring of Fluconazole and Caspofungin Activity against In Vivo Candida glabrata Biofilms by Bioluminescence Imaging

2018 ◽  
Vol 63 (2) ◽  
pp. e01555-18 ◽  
Author(s):  
Aranka Persyn ◽  
Ona Rogiers ◽  
Matthias Brock ◽  
Greetje Vande Velde ◽  
Mohamed Lamkanfi ◽  
...  
Keyword(s):  
Real Time ◽  
Biofilm Formation ◽  
Candida Glabrata ◽  
Bioluminescence Imaging ◽  
Firefly Luciferase ◽  
Antibiofilm Activity ◽  
Limited Information ◽  
Content Type ◽  
Abiotic Surfaces

ABSTRACT Candida glabrata can attach to various medical implants and forms thick biofilms despite its inability to switch from yeast to hyphae. The current in vivo C. glabrata biofilm models only provide limited information about colonization and infection and usually require animal sacrifice. To gain real-time information from individual BALB/c mice, we developed a noninvasive imaging technique to visualize C. glabrata biofilms in catheter fragments that were subcutaneously implanted on the back of mice. Bioluminescent C. glabrata reporter strains (lucOPT 7/2/4 and lucOPT 8/1/4), free of auxotrophic markers, expressing a codon-optimized firefly luciferase were generated. A murine subcutaneous model was used to follow real-time in vivo biofilm formation in the presence and absence of fluconazole and caspofungin. The fungal load in biofilms was quantified by CFU counts and by bioluminescence imaging (BLI). C. glabrata biofilms formed within the first 24 h, as documented by the increased number of device-associated cells and elevated bioluminescent signal compared with adhesion at the time of implant. The in vivo model allowed monitoring of the antibiofilm activity of caspofungin against C. glabrata biofilms through bioluminescent imaging from day four after the initiation of treatment. Contrarily, signals emitted from biofilms implanted in fluconazole-treated mice were similar to the light emitted from control-treated mice. This study gives insights into the real-time development of C. glabrata biofilms under in vivo conditions. BLI proved to be a dynamic, noninvasive, and sensitive tool to monitor continuous biofilm formation and activity of antifungal agents against C. glabrata biofilms formed on abiotic surfaces in vivo.

scholarly journals Accumulation-Associated Protein Enhances Staphylococcus epidermidis Biofilm Formation under Dynamic Conditions and Is Required for Infection in a Rat Catheter Model

2014 ◽  
Vol 83 (1) ◽  
pp. 214-226 ◽  
Author(s):  
Carolyn R. Schaeffer ◽  
Keith M. Woods ◽  
G. Matt Longo ◽  
Megan R. Kiedrowski ◽  
Alexandra E. Paharik ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Host Cells ◽  
Content Type ◽  
Microtiter Plates ◽  
Allelic Replacement ◽  
Abiotic Surfaces ◽  
Cell Accumulation ◽  
Accumulation Associated Protein

Biofilm formation is the primary virulence factor ofStaphylococcus epidermidis.S. epidermidisbiofilms preferentially form on abiotic surfaces and may contain multiple matrix components, including proteins such as accumulation-associated protein (Aap). Following proteolytic cleavage of the A domain, which has been shown to enhance binding to host cells, B domain homotypic interactions support cell accumulation and biofilm formation. To further define the contribution of Aap to biofilm formation and infection, we constructed anaapallelic replacement mutant and anicaADBC aapdouble mutant. When subjected to fluid shear, strains deficient in Aap production produced significantly less biofilm than Aap-positive strains. To examine thein vivorelevance of our findings, we modified our previously described rat jugular catheter model and validated the importance of immunosuppression and the presence of a foreign body to the establishment of infection. The use of our allelic replacement mutants in the model revealed a significant decrease in bacterial recovery from the catheter and the blood in the absence of Aap, regardless of the production of polysaccharide intercellular adhesin (PIA), a well-characterized, robust matrix molecule. Complementation of theaapmutant with full-length Aap (containing the A domain), but not the B domain alone, increased initial attachment to microtiter plates, as did intransexpression of the A domain in adhesion-deficientStaphylococcus carnosus. These results demonstrate Aap contributes toS. epidermidisinfection, which may in part be due to A domain-mediated attachment to abiotic surfaces.

scholarly journals Pneumococcal Interactions with Epithelial Cells Are Crucial for Optimal Biofilm Formation and ColonizationIn VitroandIn Vivo

2012 ◽  
Vol 80 (8) ◽  
pp. 2744-2760 ◽  
Author(s):  
Laura R. Marks ◽  
G. Iyer Parameswaran ◽  
Anders P. Hakansson
Keyword(s):  
Epithelial Cells ◽  
Biofilm Formation ◽  
Invasive Disease ◽  
Respiratory Epithelial Cells ◽  
Symptomatic Infection ◽  
Content Type ◽  
Abiotic Surfaces ◽  
Horizontal Spread ◽  
Respiratory Epithelial

ABSTRACTThe human nasopharynx is the main reservoir forStreptococcus pneumoniae(the pneumococcus) and the source for both horizontal spread and transition to infection. Some clinical evidence indicates that nasopharyngeal carriage is harder to eradicate with antibiotics than is pneumococcal invasive disease, which may suggest that colonizing pneumococci exist in biofilm communities that are more resistant to antibiotics. While pneumococcal biofilms have been observed during symptomatic infection, their role in colonization and the role of host factors in this process have been less studied. Here, we show for the first time that pneumococci form highly structured biofilm communities during colonization of the murine nasopharynx that display increased antibiotic resistance. Furthermore, pneumococcal biofilms grown on respiratory epithelial cells exhibited phenotypes similar to those observed during colonizationin vivo, whereas abiotic surfaces produced less ordered and more antibiotic-sensitive biofilms. The importance of bacterial-epithelial cell interactions during biofilm formation was shown using both clinical strains with variable colonization efficacies and pneumococcal mutants with impaired colonization characteristicsin vivo. In both cases, the ability of strains to form biofilms on epithelial cells directly correlated with their ability to colonize the nasopharynxin vivo, with colonization-deficient strains forming less structured and more antibiotic-sensitive biofilms on epithelial cells, an association that was lost when grown on abiotic surfaces. Thus, these studies emphasize the importance of host-bacterial interactions in pneumococcal biofilm formation and provide the first experimental data to explain the high resistance of pneumococcal colonization to eradication by antibiotics.

scholarly journals Biofilm Formation on Biotic and Abiotic Surfaces in the Presence of Antimicrobials by Escherichia coli Isolates from Cases of Bovine Mastitis

2014 ◽  
Vol 80 (19) ◽  
pp. 6136-6145 ◽  
Author(s):  
Vitor O. Silva ◽  
Larissa O. Soares ◽  
Abelardo Silva Júnior ◽  
Hilário C. Mantovani ◽  
Yung-Fu Chang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Expression Profiles ◽  
Bovine Mastitis ◽  
Pcr Analysis ◽  
Content Type ◽  
E Coli ◽  
Biofilm Production ◽  
Abiotic Surfaces

ABSTRACTEscherichia coliis a highly adaptive microorganism, and its ability to form biofilms under certain conditions can be critical for antimicrobial resistance. The adhesion of fourE. coliisolates from bovine mastitis to bovine mammary alveolar (MAC-T) cells, biofilm production on a polystyrene surface, and the expression profiles of the genesfliC,csgA,fimA, andluxSin the presence of enrofloxacin, gentamicin, co-trimoxazole, and ampicillin at half of the MIC were investigated. Increased adhesion ofE. coliisolates in the presence of antimicrobials was not observed; however, increased internalization of some isolates was observed by confocal microscopy. All of the antimicrobials induced the formation of biofilms by at least one isolate, whereas enrofloxacin and co-trimoxazole decreased biofilm formation by at least one isolate. Quantitative PCR analysis revealed that all four genes were differentially expressed when bacteria were exposed to subinhibitory concentrations of antimicrobials, with expression altered on the order of 1.5- to 22-fold. However, it was not possible to associate gene expression with induction or reduction of biofilm formation in the presence of the antimicrobials. Taken together, the results demonstrate that antimicrobials could induce biofilm formation by some isolates, in addition to inducing MAC-T cell invasion, a situation that might occurin vivo, potentially resulting in a bacterial reservoir in the udder, which might explain some cases of persistent mastitis in herds.

scholarly journals Multi-Modal Multi-Spectral Intravital Microscopic Imaging of Signaling Dynamics in Real-Time during Tumor–Immune Interactions

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 499
Author(s):  
Tracy W. Liu ◽  
Seth T. Gammon ◽  
David Piwnica-Worms
Keyword(s):  
Molecular Imaging ◽  
Single Cell ◽  
Real Time ◽  
Bioluminescence Imaging ◽  
Emission Spectra ◽  
Ccd Camera ◽  
Microscopic Imaging ◽  
Signaling Dynamics ◽  
Window Chamber

Intravital microscopic imaging (IVM) allows for the study of interactions between immune cells and tumor cells in a dynamic, physiologically relevant system in vivo. Current IVM strategies primarily use fluorescence imaging; however, with the advances in bioluminescence imaging and the development of new bioluminescent reporters with expanded emission spectra, the applications for bioluminescence are extending to single cell imaging. Herein, we describe a molecular imaging window chamber platform that uniquely combines both bioluminescent and fluorescent genetically encoded reporters, as well as exogenous reporters, providing a powerful multi-plex strategy to study molecular and cellular processes in real-time in intact living systems at single cell resolution all in one system. We demonstrate that our molecular imaging window chamber platform is capable of imaging signaling dynamics in real-time at cellular resolution during tumor progression. Importantly, we expand the utility of IVM by modifying an off-the-shelf commercial system with the addition of bioluminescence imaging achieved by the addition of a CCD camera and demonstrate high quality imaging within the reaches of any biology laboratory.

scholarly journals Abrogation of Neuraminidase Reduces Biofilm Formation, Capsule Biosynthesis, and Virulence of Porphyromonas gingivalis

2011 ◽  
Vol 80 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Chen Li ◽  
Kurniyati ◽  
Bo Hu ◽  
Jiang Bian ◽  
Jianlan Sun ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Biofilm Formation ◽  
Adult Population ◽  
Transcriptional Analysis ◽  
Wild Type ◽  
Content Type ◽  
Multiple Organs ◽  
Biochemical Analyses

ABSTRACTThe oral bacteriumPorphyromonas gingivalisis a key etiological agent of human periodontitis, a prevalent chronic disease that affects up to 80% of the adult population worldwide.P. gingivalisexhibits neuraminidase activity. However, the enzyme responsible for this activity, its biochemical features, and its role in the physiology and virulence ofP. gingivalisremain elusive. In this report, we found thatP. gingivalisencodes a neuraminidase, PG0352 (SiaPg). Transcriptional analysis showed thatPG0352is monocistronic and is regulated by a sigma70-like promoter. Biochemical analyses demonstrated that SiaPgis an exo-α-neuraminidase that cleaves glycosidic-linked sialic acids. Cryoelectron microscopy and tomography analyses revealed that thePG0352deletion mutant (ΔPG352) failed to produce an intact capsule layer. Compared to the wild type,in vitrostudies showed that ΔPG352 formed less biofilm and was less resistant to killing by the host complement.In vivostudies showed that while the wild type caused a spreading type of infection that affected multiple organs and all infected mice were killed, ΔPG352 only caused localized infection and all animals survived. Taken together, these results demonstrate that SiaPgis an important virulence factor that contributes to the biofilm formation, capsule biosynthesis, and pathogenicity ofP. gingivalis, and it can potentially serve as a new target for developing therapeutic agents againstP. gingivalisinfection.

scholarly journals An optimised GAS-pharyngeal cell biofilm model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Heema K. N. Vyas ◽  
Jason D. McArthur ◽  
Martina L. Sanderson-Smith
Keyword(s):  
Crystal Violet ◽  
Biofilm Formation ◽  
Cell Model ◽  
Matrix Material ◽  
Three Dimensional ◽  
Growth Period ◽  
Optimal Growth ◽  
Abiotic Surfaces

AbstractGroup A Streptococcus (GAS) causes 700 million infections and accounts for half a million deaths per year. Biofilm formation has been implicated in both pharyngeal and dermal GAS infections. In vitro, plate-based assays have shown that several GAS M-types form biofilms, and multiple GAS virulence factors have been linked to biofilm formation. Although the contributions of these plate-based studies have been valuable, most have failed to mimic the host environment, with many studies utilising abiotic surfaces. GAS is a human specific pathogen, and colonisation and subsequent biofilm formation is likely facilitated by distinct interactions with host tissue surfaces. As such, a host cell-GAS model has been optimised to support and grow GAS biofilms of a variety of GAS M-types. Improvements and adjustments to the crystal violet biofilm biomass assay have also been tailored to reproducibly detect delicate GAS biofilms. We propose 72 h as an optimal growth period for yielding detectable biofilm biomass. GAS biofilms formed are robust and durable, and can be reproducibly assessed via staining/washing intensive assays such as crystal violet with the aid of methanol fixation prior to staining. Lastly, SEM imaging of GAS biofilms formed by this model revealed GAS cocci chains arranged into three-dimensional aggregated structures with EPS matrix material. Taken together, we outline an efficacious GAS biofilm pharyngeal cell model that can support long-term GAS biofilm formation, with biofilms formed closely resembling those seen in vivo.

2021 Frank Stinchfield Award: A novel cemented hip hemiarthroplasty infection model with real-time in vivo imaging in rats

2021 ◽  
Vol 103-B (7 Supple B) ◽  
pp. 9-16
Author(s):  
William J. Hadden ◽  
Mazen Ibrahim ◽  
Mariam Taha ◽  
Kerstin Ure ◽  
Yun Liu ◽  
...  
Keyword(s):  
Real Time ◽  
In Vivo Imaging ◽  
Biofilm Formation ◽  
Joint Infection ◽  
Volumetric Analysis ◽  
In Vivo Model ◽  
Infection Model ◽  
Sprague Dawley ◽  
Hip Hemiarthroplasty

Aims The aims of this study were to develop an in vivo model of periprosthetic joint infection (PJI) in cemented hip hemiarthroplasty, and to monitor infection and biofilm formation in real-time. Methods Sprague-Dawley rats underwent cemented hip hemiarthroplasty via the posterior approach with pre- and postoperative gait assessments. Infection with Staphylococcus aureus Xen36 was monitored with in vivo photoluminescent imaging in real-time. Pre- and postoperative gait analyses were performed and compared. Postmortem micro (m) CT was used to assess implant integration; field emission scanning electron microscopy (FE-SEM) was used to assess biofilm formation on prosthetic surfaces. Results All animals tolerated surgery well, with preservation of gait mechanics and weightbearing in control individuals. Postoperative in vivo imaging demonstrated predictable evolution of infection with logarithmic signal decay coinciding with abscess formation. Postmortem mCT qualitative volumetric analysis showed high contact area and both cement-bone and cement-implant interdigitation. FE-SEM revealed biofilm formation on the prosthetic head. Conclusion This study demonstrates the utility of a new, high-fidelity model of in vivo PJI using cemented hip hemiarthroplasty in rats. Inoculation with bioluminescent bacteria allows for non-invasive, real-time monitoring of infection. Cite this article: Bone Joint J 2021;103-B(7 Supple B):9–16.

Real-time in vivo bioluminescence imaging of drug-induced oxidative stress

2016 ◽  
Vol 258 ◽  
pp. S234
Author(s):  
S. Seyed Forootan ◽  
F. Mutter ◽  
J. Clarke ◽  
A. Kipar ◽  
K. Park ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Real Time ◽  
Bioluminescence Imaging ◽  
Drug Induced ◽  
In Vivo Bioluminescence Imaging

scholarly journals A Light-Regulated Type I Pilus Contributes toAcinetobacter baumanniiBiofilm, Motility, and Virulence Functions

2018 ◽  
Vol 86 (9) ◽  
Author(s):  
Cecily R. Wood ◽  
Emily J. Ohneck ◽  
Richard E. Edelmann ◽  
Luis A. Actis
Keyword(s):  
Biofilm Formation ◽  
Galleria Mellonella ◽  
Alveolar Epithelial Cells ◽  
Ecological Niches ◽  
Type I ◽  
Pellicle Formation ◽  
Content Type ◽  
Alveolar Epithelial ◽  
Abiotic Surfaces ◽  
Cells Cultured

ABSTRACTTranscriptional analyses ofAcinetobacter baumanniiATCC 17978 showed that the expression of A1S_2091 was enhanced in cells cultured in darkness at 24°C through a process that depended on the BlsA photoreceptor. Disruption of A1S_2091, a component of the A1S_2088-A1S_2091 polycistronic operon predicted to code for a type I chaperone/usher pilus assembly system, abolished surface motility and pellicle formation but significantly enhanced biofilm formation on plastic by bacteria cultured in darkness. Based on these observations, the A1S_2088-A1S_2091 operon was named thephotoregulatedpilus ABCD (prpABCD) operon, with A1S_2091 coding for the PrpA pilin subunit. Unexpectedly, comparative analyses of ATCC 17978 andprpAisogenic mutant cells cultured at 37°C showed the expression of light-regulated biofilm biogenesis and motility functions under a temperature condition that drastically affects BlsA production and its light-sensing activity. These assays also suggest that ATCC 17978 cells produce alternative light-regulated adhesins and/or pilus systems that enhance bacterial adhesion and biofilm formation at both 24°C and 37°C on plastic as well as on the surface of polarized A549 alveolar epithelial cells, where the formation of bacterial filaments and cell chains was significantly enhanced. The inactivation ofprpAalso resulted in a significant reduction in virulence when tested by using theGalleria mellonellavirulence model. All these observations provide strong evidence showing the capacity ofA. baumanniito sense light and interact with biotic and abiotic surfaces using undetermined alternative sensing and regulatory systems as well as alternative adherence and motility cellular functions that allow this pathogen to persist in different ecological niches.

scholarly journals Probiotic Yeasts Inhibit Virulence of Non-albicans Candida Species

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Lohith Kunyeit ◽  
Nawneet K. Kurrey ◽  
K. A. Anu-Appaiah ◽  
Reeta P. Rao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Tropicalis ◽  
Biofilm Formation ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Candida Krusei ◽  
Probiotic Properties ◽  
Candida Auris ◽  
Content Type ◽  
Alternative Approach

ABSTRACT Systemic infections of Candida species pose a significant threat to public health. Toxicity associated with current therapies and emergence of resistant strains present major therapeutic challenges. Here, we report exploitation of the probiotic properties of two novel, food-derived yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (strain ApC), as an alternative approach to combat widespread opportunistic fungal infections. Both yeasts inhibit virulence traits such as adhesion, filamentation, and biofilm formation of several non-albicans Candida species, including Candida tropicalis, Candida krusei, Candida glabrata, and Candida parapsilosis as well as the recently identified multidrug-resistant species Candida auris. They inhibit adhesion to abiotic surfaces as well as cultured colon epithelial cells. Furthermore, probiotic treatment blocks the formation of biofilms of individual non-albicans Candida strains as well as mixed-culture biofilms of each non-albicans Candida strain in combination with Candida albicans. The probiotic yeasts attenuated non-albicans Candida infections in a live animal. In vivo studies using Caenorhabditis elegans suggest that exposure to probiotic yeasts protects nematodes from infection with non-albicans Candida strains compared to worms that were not exposed to the probiotic yeasts. Furthermore, application of probiotic yeasts postinfection with non-albicans Candida alleviated pathogenic colonization of the nematode gut. The probiotic properties of these novel yeasts are better than or comparable to those of the commercially available probiotic yeast Saccharomyces boulardii, which was used as a reference strain throughout this study. These results indicate that yeasts derived from food sources could serve as an effective alternative to antifungal therapy against emerging pathogenic Candida species. IMPORTANCE Non-albicans Candida-associated infections have emerged as a major risk factor in the hospitalized and immunecompromised patients. Besides, antifungal-associated complications occur more frequently with these non-albicans Candida species than with C. albicans. Therefore, as an alternative approach to combat these widespread non-albicans Candida-associated infections, here we showed the probiotic effect of two yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (ApC), in preventing adhesion and biofilm formation of five non-albicans Candida strains, Candida tropicalis, Candida krusei, Candida glabrata, Candida parapsilosis, and Candida auris. The result would influence the current trend of the conversion of conventional antimicrobial therapy into beneficial probiotic microbe-associated antimicrobial treatment.

Sign in / Sign up

Export Citation Format

Share Document