scholarly journals Use of an Oxygen Planar Optode to Assess the Effect of High Velocity Microsprays on Oxygen Penetration in a Human Dental Biofilms In-Vitro

2020 ◽  
Author(s):  
Yalda Khosravi ◽  
Raja Durga Prasad Kandukuri ◽  
Sara Palmer ◽  
Erin Samantha Gloag ◽  
Sergey M. Borisov ◽  
...  
Keyword(s):  
High Velocity ◽  
Antimicrobial Agents ◽  
Individual Species ◽  
Oxygen Penetration ◽  
16S Rna ◽  
Fluid Jets ◽  
Planar Optode ◽  
Causative Agents ◽  
The Impact

Abstract Background Dental plaque biofilms are the causative agents of caries, gingivitis and periodontitis. Both mechanical and chemical strategies are used in routine oral hygiene strategies to reduce plaque build-up. If allowed to mature biofilms can create anoxic microenvironments leading to communities which harbor pathogenic Gram-negative anaerobes. When subjected to high velocity fluid jets and sprays biofilms can be fluidized which disrupts the biofilm structure and allows the more efficient delivery of antimicrobial agents. Methods To investigate how such jets may disrupt anoxic niches in the biofilm, we used planar optodes to measure the dissolved oxygen (DO) concentration at the base of in-vitro biofilms grown from human dental saliva and plaque. These biofilms were subject to “shooting” treatments with a commercial high velocity microspray (HVM) device. Results HVM treatment resulted in removal of much of the biofilm and a concurrent rapid shift from anoxic to oxic conditions at the base of the surrounding biofilm. We also assessed the impact of HVM treatment on the microbial community by tracking 7 target species by qRT-PCR. There was a general reduction in copy numbers of the universal 16S RNA by approximately 95%, and changes of individual species in the target region ranged from approximately 1 to 4 log reductions. Conclusion We concluded that high velocity microsprays removed a sufficient amount of biofilm to disrupt the anoxic region at the biofilm-surface interface.

scholarly journals Use of an Oxygen Planar Optode to Assess the Effect of High Velocity Microsprays on Oxygen Penetration in a Human Dental Biofilms In-Vitro

2020 ◽  
Author(s):  
Yalda Khosravi ◽  
Raja Durga Prasad Kandukuri ◽  
Sara Palmer ◽  
Erin Samantha Gloag ◽  
Sergey M. Borisov ◽  
...  
Keyword(s):  
High Velocity ◽  
Antimicrobial Agents ◽  
Individual Species ◽  
Oxygen Penetration ◽  
16S Rna ◽  
Fluid Jets ◽  
Planar Optode ◽  
Causative Agents ◽  
The Impact

Abstract Background Dental plaque biofilms are the causative agents of caries, gingivitis and periodontitis. Both mechanical and chemical strategies are used in routine oral hygiene strategies to reduce plaque build-up. If allowed to mature biofilms can create anoxic microenvironments leading to communities which harbor pathogenic Gram-negative anaerobes. When subjected to high velocity fluid jets and sprays biofilms can be fluidized which disrupts the biofilm structure and allows the more efficient delivery of antimicrobial agents. Methods To investigate how such jets may disrupt anoxic niches in the biofilm, we used planar optodes to measure the dissolved oxygen (DO) concentration at the base of in-vitro biofilms grown from human dental saliva and plaque. These biofilms were subject to “shooting” treatments with a commercial high velocity microspray (HVM) device. Results HVM treatment resulted in removal of much of the biofilm and a concurrent rapid shift from anoxic to oxic conditions at the base of the surrounding biofilm. We also assessed the impact of HVM treatment on the microbial community by tracking 7 target species by qRT-PCR. There was a general reduction in copy numbers of the universal 16S RNA by approximately 95%, and changes of individual species in the target region ranged from approximately 1 to 4 log reductions. Conclusion We concluded that high velocity microsprays removed a sufficient amount of biofilm to disrupt the anoxic region at the biofilm-surface interface.

scholarly journals Use of an Oxygen Planar Optode to Assess the Effect of High Velocity Microsprays on Oxygen Penetration in a Human Dental Biofilms In-Vitro

2019 ◽  
Author(s):  
Yalda Khosravi ◽  
Raja Durga Prasad Kandukuri ◽  
Sara Palmer ◽  
Sergey M. Borisov ◽  
Michelle Starke ◽  
...  
Keyword(s):  
High Velocity ◽  
Antimicrobial Agents ◽  
Individual Species ◽  
Oxygen Penetration ◽  
16S Rna ◽  
Fluid Jets ◽  
Planar Optode ◽  
Causative Agents ◽  
The Impact

Abstract Background Dental plaque biofilms are the causative agents of caries, gingivitis and periodontitis. Both mechanical and chemical strategies are used in routine oral hygiene strategies to reduce plaque build-up. If allowed to mature biofilms can create anoxic microenvironments leading to communities which harbor pathogenic Gram-negative anaerobes. When subjected to high velocity fluid jets and sprays biofilms can be fluidized which disrupts the biofilm structure and allows the more efficient delivery of antimicrobial agents. Methods To investigate how such jets may disrupt anoxic niches in the biofilm, we used planar optodes to measure the dissolved oxygen (DO) concentration at the base of in-vitro biofilms grown from human dental saliva and plaque. These biofilms were subject to “shooting” treatments with a commercial high velocity microspray (HVM) device. Results HVM treatment resulted in removal of much of the biofilm and a concurrent rapid shift from anoxic to oxic conditions at the base of the surrounding biofilm. We also assessed the impact of HVM treatment on the microbial community by tracking 7 target species by qRT-PCR. There was a general reduction in copy numbers of the universal 16S RNA by approximately 95%, and changes of individual species in the target region ranged from approximately 1 to 4 log reductions. Conclusion We concluded that high velocity microsprays removed a sufficient amount of biofilm to disrupt the anoxic region at the biofilm-surface interface.

scholarly journals Use of an Oxygen Planar Optode to Assess the Effect of High Velocity Microsprays on Oxygen Penetration in a Human Dental Biofilms In-Vitro

2020 ◽  
Author(s):  
Yalda Khosravi ◽  
Raja Durga Prasad Kandukuri ◽  
Sara Palmer ◽  
Erin S Gloag ◽  
Sergey M. Borisov ◽  
...  
Keyword(s):  
High Velocity ◽  
Individual Species ◽  
Oxygen Penetration ◽  
Copy Numbers ◽  
16S Rna ◽  
Fluid Jets ◽  
Planar Optode ◽  
Causative Agents ◽  
The Impact

Abstract BackgroundDental plaque biofilms are the causative agents of caries, gingivitis and periodontitis. Both mechanical and chemical strategies are used in routine oral hygiene strategies to reduce plaque build-up. If allowed to mature biofilms can create anoxic microenvironments leading to communities which harbor pathogenic Gram-negative anaerobes. When subjected to high velocity fluid jets and sprays biofilms can be fluidized which disrupts the biofilm structure and allows the more efficient delivery of antimicrobial agents.MethodsTo investigate how such jets may disrupt anoxic niches in the biofilm, we used planar optodes to measure the dissolved oxygen (DO) concentration at the base of in-vitro biofilms grown from human dental saliva and plaque. These biofilms were subject to “shooting” treatments with a commercial high velocity microspray (HVM) device.ResultsHVM treatment resulted in removal of much of the biofilm and a concurrent rapid shift from anoxic to oxic conditions at the base of the surrounding biofilm. We also assessed the impact of HVM treatment on the microbial community by tracking 7 target species by qRT-PCR. There was a general reduction in copy numbers of the universal 16S RNA by approximately 95%, and changes of individual species in the target region ranged from approximately 1 to 4 log reductions.ConclusionWe concluded that high velocity microsprays removed a sufficient amount of biofilm to disrupt the anoxic region at the biofilm-surface interface.

scholarly journals Use of an oxygen planar optode to assess the effect of high velocity microsprays on oxygen penetration in a human dental biofilms in-vitro

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yalda Khosravi ◽  
Rala D.P. Kandukuri ◽  
Sara R. Palmer ◽  
Erin S. Gloag ◽  
Sergey M. Borisov ◽  
...  
Keyword(s):  
High Velocity ◽  
Oxygen Penetration ◽  
Planar Optode

scholarly journals Correction to: Use of an oxygen planar optode to assess the effect of high velocity microsprays on oxygen penetration in a human dental biofilms in-vitro

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yalda Khosravi ◽  
Rala D. P. Kandukuri ◽  
Sara R. Palmer ◽  
Erin S. Gloag ◽  
Sergey M. Borisov ◽  
...  
Keyword(s):  
High Velocity ◽  
Oxygen Penetration ◽  
Planar Optode

scholarly journals In VivoEfficacy of Anuran Trypsin Inhibitory Peptides against Staphylococcal Skin Infection and the Impact of Peptide Cyclization

2015 ◽  
Vol 59 (4) ◽  
pp. 2113-2121 ◽  
Author(s):  
U. Malik ◽  
O. N. Silva ◽  
I. C. M. Fensterseifer ◽  
L. Y. Chan ◽  
R. J. Clark ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Cyclic Peptide ◽  
Sequence Similarity ◽  
Infection Model ◽  
Content Type ◽  
Wide Range ◽  
Inhibitory Activities ◽  
The Impact

ABSTRACTStaphylococcus aureusis a virulent pathogen that is responsible for a wide range of superficial and invasive infections. Its resistance to existing antimicrobial drugs is a global problem, and the development of novel antimicrobial agents is crucial. Antimicrobial peptides from natural resources offer potential as new treatments against staphylococcal infections. In the current study, we have examined the antimicrobial properties of peptides isolated from anuran skin secretions and cyclized synthetic analogues of these peptides. The structures of the peptides were elucidated by nuclear magnetic resonance (NMR) spectroscopy, revealing high structural and sequence similarity with each other and with sunflower trypsin inhibitor 1 (SFTI-1). SFTI-1 is an ultrastable cyclic peptide isolated from sunflower seeds that has subnanomolar trypsin inhibitory activity, and this scaffold offers pharmaceutically relevant characteristics. The five anuran peptides were nonhemolytic and noncytotoxic and had trypsin inhibitory activities similar to that of SFTI-1. They demonstrated weakin vitroinhibitory activities againstS. aureus, but several had strong antibacterial activities againstS. aureusin anin vivomurine wound infection model. pYR, an immunomodulatory peptide fromRana sevosa, was the most potent, with complete bacterial clearance at 3 mg · kg−1. Cyclization of the peptides improved their stability but was associated with a concomitant decrease in antimicrobial activity. In summary, these anuran peptides are promising as novel therapeutic agents for treating infections from a clinically resistant pathogen.

scholarly journals The Effect of pH on Antibiotic Efficacy against Coxiella burnetii in Axenic Media

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Cody B. Smith ◽  
Charles Evavold ◽  
Gilbert J. Kersh
Keyword(s):  
Coxiella Burnetii ◽  
Antimicrobial Agents ◽  
Q Fever ◽  
Antimicrobial Treatment ◽  
Etiologic Agent ◽  
Growth And Survival ◽  
Intracellular Compartments ◽  
The Impact

AbstractCoxiella burnetii, the etiologic agent of Q fever, replicates in an intracellular phagolysosome with pH between 4 and 5. The impact of this low pH environment on antimicrobial treatment is not well understood. An in vitro system for testing antibiotic susceptibility of C. burnetii in axenic media was set up to evaluate the impact of pH on C. burnetii growth and survival in the presence and absence of antimicrobial agents. The data show that C. burnetii does not grow in axenic media at pH 6.0 or higher, but the organisms remain viable. At pH of 4.75, 5.25, and 5.75 moxifloxacin, doxycycline, and rifampin are effective at preventing growth of C. burnetii in axenic media, with moxifloxacin and doxycycline being bacteriostatic and rifampin having bactericidal activity. The efficacy of doxycycline and moxifloxacin improved at higher pH, whereas rifampin activity was pH independent. Hydroxychloroquine is thought to inhibit growth of C. burnetii in vivo by raising the pH of typically acidic intracellular compartments. It had no direct bactericidal or bacteriostatic activity on C. burnetii in axenic media, suggesting that raising pH of acidic intracellular compartments is its primary mechanism of action in vivo. The data suggest that doxycycline and hydroxychloroquine are primarily independent bacteriostatic agents.

scholarly journals Apotransferrin in Combination with Ciprofloxacin Slows Bacterial Replication, Prevents Resistance Amplification, and Increases Antimicrobial Regimen Effect

2019 ◽  
Vol 63 (5) ◽  
Author(s):  
Paul G. Ambrose ◽  
Brian D. VanScoy ◽  
Brian M. Luna ◽  
Jun Yan ◽  
Amber Ulhaq ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Bactericidal Effect ◽  
Bacterial Density ◽  
Infection Model ◽  
Time Curve ◽  
Content Type ◽  
Wide Range ◽  
Bacterial Replication ◽  
The Impact

ABSTRACT There has been renewed interest in combining traditional small-molecule antimicrobial agents with nontraditional therapies to potentiate antimicrobial effects. Apotransferrin, which decreases iron availability to microbes, is one such approach. We conducted a 48-h one-compartment in vitro infection model to explore the impact of apotransferrin on the bactericidal activity of ciprofloxacin. The challenge panel included four Klebsiella pneumoniae isolates with ciprofloxacin MIC values ranging from 0.08 to 32 mg/liter. Each challenge isolate was subjected to an ineffective ciprofloxacin monotherapy exposure (free-drug area under the concentration-time curve over 24 h divided by the MIC [AUC/MIC ratio] ranging from 0.19 to 96.6) with and without apotransferrin. As expected, the no-treatment and apotransferrin control arms showed unaltered prototypical logarithmic bacterial growth. We identified relationships between exposure and change in bacterial density for ciprofloxacin alone (R2 = 0.64) and ciprofloxacin in combination with apotransferrin (R2 = 0.84). Addition of apotransferrin to ciprofloxacin enabled a remarkable reduction in bacterial density across a wide range of ciprofloxacin exposures. For instance, at a ciprofloxacin AUC/MIC ratio of 20, ciprofloxacin monotherapy resulted in nearly 2 log10 CFU increase in bacterial density, while the combination of apotransferrin and ciprofloxacin resulted in 2 log10 CFU reduction in bacterial density. Furthermore, addition of apotransferrin significantly reduced the emergence of ciprofloxacin-resistant subpopulations compared to monotherapy. These data demonstrate that decreasing the rate of bacterial replication with apotransferrin in combination with antimicrobial therapy represents an opportunity to increase the magnitude of the bactericidal effect and to suppress the growth rate of drug-resistant subpopulations.

scholarly journals Evaluating the Rapid Emergence of Daptomycin Resistance in Corynebacterium: A Multi-Center Study

2021 ◽  
Author(s):  
Kaitlin F. Mitchell ◽  
Erin McElvania ◽  
Meghan A. Wallace ◽  
Lauren E. Droske ◽  
Amy E. Robertson ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Exposure Period ◽  
Corynebacterium Striatum ◽  
Before And After ◽  
Multi Center Study ◽  
High Level ◽  
The Impact ◽  
Repeated Subculture ◽  
Center Study

Background: Members of the genus Corynebacterium are increasingly recognized as pathobionts and can be very resistant to antimicrobial agents. Previous studies have demonstrated that Corynebacterium striatum can rapidly develop high-level daptomycin resistance (HLDR) (minimum inhibitory concentration [MIC] ≥256 μg/mL). Here we conducted a multi-center study to assay for this in vitro phenotype in diverse Corynebacterium species. Methods: Corynebacterium clinical isolates (n=157) from four medical centers were evaluated. MIC values to daptomycin, vancomycin, and telavancin were determined before and after overnight exposure to daptomycin to identify isolates able to rapidly develop daptomycin non-susceptibility. To investigate assay reproducibility, 18 isolates were evaluated at three study sites. In addition, stability of daptomycin non-susceptibility was tested using repeated subculture without selective pressure. The impact of different media brands was also investigated. Results: Daptomycin non-susceptibility emerged in 12 of 23 species evaluated in this study (C. afermentans, amycolatum, aurimucosum, bovis, jeikeium, macginleyi, pseudodiphtheriticum, resistens, simulans, striatum, tuberculostearicum, and ulcerans) and was detected in 50 of 157 (31.8%) isolates tested. All isolates displayed low (susceptible) MIC values to vancomycin and telavancin before and after daptomycin exposure. Repeated subculture demonstrated 2 of 9 isolates (22.2%) exhibiting HLDR reverted to a susceptible phenotype. Of 30 isolates tested on three media brands, 13 (43.3%) had differences in daptomycin MIC values between brands. Conclusions: Multiple Corynebacterium species can rapidly develop daptomycin non-susceptibility, including HLDR, after a short daptomycin exposure period.

scholarly journals High-Velocity Microsprays Enhance Antimicrobial Activity in Streptococcus mutans Biofilms

2016 ◽  
Vol 95 (13) ◽  
pp. 1494-1500 ◽  
Author(s):  
S. Fabbri ◽  
D.A. Johnston ◽  
A. Rmaile ◽  
B. Gottenbos ◽  
M. De Jager ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
High Velocity ◽  
Antimicrobial Agents ◽  
Cetylpyridinium Chloride ◽  
Complex Structure ◽  
Impact Angle ◽  
Shear Stresses ◽  
Bacteria Killing ◽  
The Impact ◽  
Velocity Water

Streptococcus mutans in dental plaque biofilms play a role in caries development. The biofilm’s complex structure enhances the resistance to antimicrobial agents by limiting the transport of active agents inside the biofilm. The authors assessed the ability of high-velocity water microsprays to enhance delivery of antimicrobials into 3-d-old S. mutans biofilms. Biofilms were exposed to a 90° or 30° impact, first using a 1-µm tracer bead solution (109 beads/mL) and, second, a 0.2% chlorhexidine (CHX) or 0.085% cetylpyridinium chloride (CPC) solution. For comparison, a 30-s diffusive transport and simulated mouthwash were also performed. Confocal microscopy was used to determine number and relative bead penetration depth into the biofilm. Assessment of antimicrobial penetration was determined by calculating the killing depth detected by live/dead viability staining. The authors first demonstrated that the microspray was able to deliver significantly more microbeads deeper in the biofilm compared with diffusion and mouthwashing exposures. Next, these experiments revealed that the microspray yielded better antimicrobial penetration evidenced by deeper killing inside the biofilm and a wider killing zone around the zone of clearance than diffusion alone. Interestingly the 30° impact in the distal position delivered approximately 16 times more microbeads and yielded approximately 20% more bacteria killing (for both CHX and CPC) than the 90° impact. These data suggest that high-velocity water microsprays can be used as an effective mechanism to deliver microparticles and antimicrobials inside S. mutans biofilms. High shear stresses generated at the biofilm-burst interface might have enhanced bead and antimicrobial delivery inside the remaining biofilm by combining forced advection into the biofilm matrix and physical restructuring of the biofilm itself. Further, the impact angle has potential to be optimized both for biofilm removal and active agents’ delivery inside biofilm in those protected areas where some biofilm might remain.

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