1
|
Deng R, Shi Y, Zhang Y, Zhang X, Deng S, Xia X. Precise, Sensitive Detection of Viable Foodborne Pathogenic Bacteria with a 6-Order Dynamic Range via Digital Rolling Circle Amplification. ACS Sens 2024. [PMID: 39028985 DOI: 10.1021/acssensors.4c01069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/21/2024]
Abstract
The presence of viable pathogenic bacteria in food can lead to serious foodborne diseases, thus posing a risk to human health. Here, we develop a digital rolling circle amplification (dRCA) assay that enables the precise and sensitive quantification of viable foodborne pathogenic bacteria. Directly targeting pathogenic RNAs via a ligation-based padlock probe allows for precisely discriminating viable bacteria from dead one. The one-target-one-amplicon characteristic of dRCA enables high sensitivity and a broad quantitative detection range, conferring a detection limit of 10 CFU/mL and a dynamic range of 6 orders. dRCA can detect rare viable bacteria, even at a proportion as low as 0.1%, which is 50 times more sensitive than the live/dead staining method. The high sensitivity for detecting viable bacteria accommodates dRCA for assessing sterilization efficiency. Based on the assay, we found that, for pasteurization, slightly elevating the temperature to 68 °C can reduce the heating time to 10 min, which may minimize nutrient degradation caused by high-temperature exposure. The assay can serve as a precise tool for estimating the contamination by viable pathogenic bacteria and assessing sterilization, which facilitates food safety control.
Collapse
Affiliation(s)
- Ruijie Deng
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu 610065, China
| | - Yachen Shi
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu 610065, China
| | - Yong Zhang
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu 610065, China
| | - Xinlei Zhang
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu 610065, China
| | - Sha Deng
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu 610065, China
| | - Xuhan Xia
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu 610065, China
| |
Collapse
|
2
|
Kim KH, Lévesque C, Malkhassian G, Basrani B. Efficacy of the GentleWave System in the removal of biofilm from the mesial roots of mandibular molars before and after minimal instrumentation: An ex vivo study. Int Endod J 2024; 57:922-932. [PMID: 38374488 DOI: 10.1111/iej.14044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 01/29/2024] [Indexed: 02/21/2024]
Abstract
AIM To compare the efficacy of Enterococcus faecalis biofilm removal using the GentleWave System (GWS) (Sonendo Inc, CA) on non-instrumented versus minimally instrumented root canal systems. METHODOLOGY Thirty-four mandibular molars were autoclaved and allocated to four groups: Negative control (n = 5); positive control (n = 5); Group 1: non-instrumentation + GWS (NI + GWS) (n = 12); and Group 2: minimal instrumentation + GWS (MI + GWS) (n = 12). Of 34 samples, 24 samples with Vertucci type 2 configuration within the mesial root of each sample were allocated to Groups 1 and 2 and then matched based on the working length and root canal configuration. After inoculation of samples with E. faecalis for 3 weeks, the GWS was used on Group 1 without any instrumentation and Group 2 after instrumentation of mesial canals until size 20/06v. CFU and SEM analysis were used. RESULTS Log10 (CFU/mL) from the positive control, and Group 1 and 2 were 7.41 ± 0.53, 3.41 ± 1.54, and 3.21 ± 1.54, respectively. Both groups showed a statistically significant difference in the reduction of viable E. faecalis cells compared to the positive control (Group 1 [p = .0001] and Group 2 [p < .0001]), whilst showing no significant difference between the two tested groups (p < .05). CONCLUSION The use of GWS on the non-instrumented root canal system could be an effective disinfection protocol in removing the biofilm without dentin debris formation.
Collapse
Affiliation(s)
- Kwang Ho Kim
- Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Céline Lévesque
- Microbiology, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Gevik Malkhassian
- Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Bettina Basrani
- Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
3
|
Doğan Çankaya T, Uğur Aydın Z, Erdönmez D. The effect of the enzymes trypsin and DNase I on the antimicrobial efficiency of root canal irrigation solutions. Odontology 2024; 112:929-937. [PMID: 38280114 DOI: 10.1007/s10266-023-00894-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 12/19/2023] [Indexed: 01/29/2024]
Abstract
The purpose of this study was to evaluate the antibacterial efficacy of using 2.5% NaOCl, 2% chlorhexidine (CHX), Irritrol, and chitosan-coated silver nanoparticles (AgCNPs) alone or in combination with deoxyribonuclease I (DNase I) and trypsin pre-enzyme applications in dentin samples contaminated with Enterococcus faecalis (E. faecalis) by CLSM. 144 dentin blocks with confirmed E. faecalis biofilm formation were divided randomly according to the irrigation protocol (n = 12): NaOCl, CHX, Irritrol, AgCNPs, trypsin before NaOCl, CHX, Irritrol, AgCNPs, and DNase I before NaOCl, CHX, Irritrol, AgCNPs. Dentin blocks were stained with the Live/Dead BacLight Bacterial Viability Kit and viewed with CLSM after irrigation applications. The percentage of dead and viable bacteria was calculated using ImageJ software on CLSM images. At a significance level of p < 0.05, the obtained data were analyzed using one-way Anova and post-hoc Tukey tests. In comparison with NaOCl, CHX had a higher percentage of dead bacteria, both when no pre-enzyme was applied and when DNase I was applied as a pre-enzyme (p < 0.05). There was no difference in the percentage of dead bacteria between the irrigation solutions when trypsin was applied as a pre-enzyme (p > 0.05). AgCNPs showed a higher percentage of dead bacteria when trypsin was applied as a pre-enzyme compared to other irrigation solutions (p < 0.05), while the pre-enzyme application did not affect the percentage of dead bacteria in NaOCl, CHX, and Irritrol (p > 0.05). No irrigation protocol tested was able to eliminate the E. faecalis biofilm. While the application of trypsin as a pre-enzyme improved the antimicrobial effect of AgCNPs, it did not make any difference over other irrigation solutions.
Collapse
Affiliation(s)
- Tülin Doğan Çankaya
- Department of Endodontics, Faculty of Dentistry, Alanya Alaaddin Keykubat University, Antalya, Turkey.
| | - Zeliha Uğur Aydın
- Department of Endodontics, Gülhane Faculty of Dentistry, University of Health Sciences, Ankara, Turkey
| | - Demet Erdönmez
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Düzce University, Düzce, Turkey
| |
Collapse
|
4
|
Chiang CC, Anne R, Chawla P, Shaw RM, He S, Rock EC, Zhou M, Cheng J, Gong YN, Chen YC. Deep learning unlocks label-free viability assessment of cancer spheroids in microfluidics. LAB ON A CHIP 2024; 24:3169-3182. [PMID: 38804084 PMCID: PMC11165951 DOI: 10.1039/d4lc00197d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Accepted: 05/22/2024] [Indexed: 05/29/2024]
Abstract
Despite recent advances in cancer treatment, refining therapeutic agents remains a critical task for oncologists. Precise evaluation of drug effectiveness necessitates the use of 3D cell culture instead of traditional 2D monolayers. Microfluidic platforms have enabled high-throughput drug screening with 3D models, but current viability assays for 3D cancer spheroids have limitations in reliability and cytotoxicity. This study introduces a deep learning model for non-destructive, label-free viability estimation based on phase-contrast images, providing a cost-effective, high-throughput solution for continuous spheroid monitoring in microfluidics. Microfluidic technology facilitated the creation of a high-throughput cancer spheroid platform with approximately 12 000 spheroids per chip for drug screening. Validation involved tests with eight conventional chemotherapeutic drugs, revealing a strong correlation between viability assessed via LIVE/DEAD staining and phase-contrast morphology. Extending the model's application to novel compounds and cell lines not in the training dataset yielded promising results, implying the potential for a universal viability estimation model. Experiments with an alternative microscopy setup supported the model's transferability across different laboratories. Using this method, we also tracked the dynamic changes in spheroid viability during the course of drug administration. In summary, this research integrates a robust platform with high-throughput microfluidic cancer spheroid assays and deep learning-based viability estimation, with broad applicability to various cell lines, compounds, and research settings.
Collapse
Affiliation(s)
- Chun-Cheng Chiang
- UPMC Hillman Cancer Center, University of Pittsburgh, 5115 Centre Ave, Pittsburgh, PA 15232, USA.
- Department of Computational and Systems Biology, University of Pittsburgh, 3420 Forbes Avenue, Pittsburgh, PA 15260, USA
| | - Rajiv Anne
- UPMC Hillman Cancer Center, University of Pittsburgh, 5115 Centre Ave, Pittsburgh, PA 15232, USA.
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, 3700 O'Hara Street, Pittsburgh, PA 15260, USA
| | - Pooja Chawla
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, 3700 O'Hara Street, Pittsburgh, PA 15260, USA
| | - Rachel M Shaw
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, 3700 O'Hara Street, Pittsburgh, PA 15260, USA
| | - Sarah He
- UPMC Hillman Cancer Center, University of Pittsburgh, 5115 Centre Ave, Pittsburgh, PA 15232, USA.
- Carnegie Mellon University, Department of Biological Sciences, 5000 Forbes Avenue, Pittsburgh, PA, 15213, USA
| | - Edwin C Rock
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, 3700 O'Hara Street, Pittsburgh, PA 15260, USA
| | - Mengli Zhou
- UPMC Hillman Cancer Center, University of Pittsburgh, 5115 Centre Ave, Pittsburgh, PA 15232, USA.
- Department of Computational and Systems Biology, University of Pittsburgh, 3420 Forbes Avenue, Pittsburgh, PA 15260, USA
- Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Jinxiong Cheng
- UPMC Hillman Cancer Center, University of Pittsburgh, 5115 Centre Ave, Pittsburgh, PA 15232, USA.
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, 3700 O'Hara Street, Pittsburgh, PA 15260, USA
| | - Yi-Nan Gong
- UPMC Hillman Cancer Center, University of Pittsburgh, 5115 Centre Ave, Pittsburgh, PA 15232, USA.
- Department of Immunology, University of Pittsburgh School of Medicine, 3420 Forbes Avenue, Pittsburgh, PA, 15260, USA
| | - Yu-Chih Chen
- UPMC Hillman Cancer Center, University of Pittsburgh, 5115 Centre Ave, Pittsburgh, PA 15232, USA.
- Department of Computational and Systems Biology, University of Pittsburgh, 3420 Forbes Avenue, Pittsburgh, PA 15260, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, 3700 O'Hara Street, Pittsburgh, PA 15260, USA
- CMU-Pitt Ph.D. Program in Computational Biology, University of Pittsburgh, 3420 Forbes Avenue, Pittsburgh, PA 15260, USA
| |
Collapse
|
5
|
Lopes ABS, R Lima A, D Bronzato J, Herrera DR, Francisco PA, Carvalho MCC, Abuna G, Sinhoreti M, Gomes BPFA. Influence of different presentation forms of chlorhexidine on contaminated root canals during agitation. AUST ENDOD J 2024. [PMID: 38803063 DOI: 10.1111/aej.12862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 04/11/2024] [Accepted: 05/14/2024] [Indexed: 05/29/2024]
Abstract
This in vitro study aimed to verify the influence of chlorhexidine (CHX) (gel and solution) in association with different activation protocols on disinfection of root canals contaminated with Enterococcus faecalis. In total, 120 lower premolar roots were selected, contaminated and divided into 12 groups according to irrigation technique and substance. Samples were collected before and after each irrigation technique and analysed for colony-forming units (CFU). Three dentin discs were obtained for quantification of viable intratubular cells by using confocal laser scanning microscopy (CLSM). CFU results showed that sonic and ultrasonic were more effective than conventional irrigation. Ultrasonic activation was more effective than sonic for CHX gel (p < 0.05). CLSM showed that either activation was better than conventional in all groups and root canal thirds (p < 0.05). It was concluded that ultrasonic/sonic activation was more effective than conventional techniques and CHX enhanced intratubular dentin decontamination across all irrigation methods.
Collapse
Affiliation(s)
- Ana B S Lopes
- Department of Restorative Dentistry -Endodontics Division, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
| | - Augusto R Lima
- Department of Restorative Dentistry -Endodontics Division, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
| | - Juliana D Bronzato
- Department of Restorative Dentistry -Endodontics Division, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
| | - Daniel R Herrera
- Department of Restorative Dentistry -Endodontics Division, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
- Department of Endodontics, Federal Fuminense University, Rio de Janeiro, Brazil
| | - Priscila A Francisco
- Department of Restorative Dentistry -Endodontics Division, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
| | - Maria C C Carvalho
- Department of Restorative Dentistry -Endodontics Division, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
| | - Gabriel Abuna
- Department of Restorative Dentistry - Dental Materials Division, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
| | - Mario Sinhoreti
- Department of Restorative Dentistry - Dental Materials Division, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
| | - Brenda P F A Gomes
- Department of Restorative Dentistry -Endodontics Division, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
| |
Collapse
|
6
|
Waite R, Adams CT, Chisholm DR, Sims CHC, Hughes JG, Dias E, White EA, Welsby K, Botchway SW, Whiting A, Sharples GJ, Ambler CA. The antibacterial activity of a photoactivatable diarylacetylene against Gram-positive bacteria. Front Microbiol 2023; 14:1243818. [PMID: 37808276 PMCID: PMC10556703 DOI: 10.3389/fmicb.2023.1243818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/07/2023] [Indexed: 10/10/2023] Open
Abstract
The emergence of antibiotic resistance is a growing threat to human health, and therefore, alternatives to existing compounds are urgently needed. In this context, a novel fluorescent photoactivatable diarylacetylene has been identified and characterised for its antibacterial activity, which preferentially eliminates Gram-positive over Gram-negative bacteria. Experiments confirmed that the Gram-negative lipopolysaccharide-rich outer surface is responsible for tolerance, as strains with reduced outer membrane integrity showed increased susceptibility. Additionally, bacteria deficient in oxidative damage repair pathways also displayed enhanced sensitivity, confirming that reactive oxygen species production is the mechanism of antibacterial activity. This new diarylacetylene shows promise as an antibacterial agent against Gram-positive bacteria that can be activated in situ, potentially for the treatment of skin infections.
Collapse
Affiliation(s)
- Ryan Waite
- Department of Biosciences, Durham University, Science Site, Durham, United Kingdom
| | | | | | | | - Joshua G. Hughes
- Department of Biosciences, Durham University, Science Site, Durham, United Kingdom
- LightOx Limited, Newcastle, United Kingdom
- Department of Physics, Durham University, Science Site, Durham, United Kingdom
| | - Eva Dias
- LightOx Limited, Newcastle, United Kingdom
| | - Emily A. White
- Department of Biosciences, Durham University, Science Site, Durham, United Kingdom
| | - Kathryn Welsby
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, United Kingdom
| | - Stanley W. Botchway
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, United Kingdom
| | - Andrew Whiting
- LightOx Limited, Newcastle, United Kingdom
- Department of Chemistry, Durham University, Durham, United Kingdom
| | - Gary J. Sharples
- Department of Biosciences, Durham University, Science Site, Durham, United Kingdom
| | - Carrie A. Ambler
- Department of Biosciences, Durham University, Science Site, Durham, United Kingdom
- LightOx Limited, Newcastle, United Kingdom
| |
Collapse
|
7
|
Ramachandra SS, Wright P, Han P, Abdal‐hay A, Lee RSB, Ivanovski S. Evaluating models and assessment techniques for understanding oral biofilm complexity. Microbiologyopen 2023; 12:e1377. [PMID: 37642488 PMCID: PMC10464519 DOI: 10.1002/mbo3.1377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/07/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023] Open
Abstract
Oral biofilms are three-dimensional (3D) complex entities initiating dental diseases and have been evaluated extensively in the scientific literature using several biofilm models and assessment techniques. The list of biofilm models and assessment techniques may overwhelm a novice biofilm researcher. This narrative review aims to summarize the existing literature on biofilm models and assessment techniques, providing additional information on selecting an appropriate model and corresponding assessment techniques, which may be useful as a guide to the beginner biofilm investigator and as a refresher to experienced researchers. The review addresses previously established 2D models, outlining their advantages and limitations based on the growth environment, availability of nutrients, and the number of bacterial species, while also exploring novel 3D biofilm models. The growth of biofilms on clinically relevant 3D models, particularly melt electrowritten fibrous scaffolds, is discussed with a specific focus that has not been previously reported. Relevant studies on validated oral microcosm models that have recently gaining prominence are summarized. The review analyses the advantages and limitations of biofilm assessment methods, including colony forming unit culture, crystal violet, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt assays, confocal microscopy, fluorescence in situ hybridization, scanning electron microscopy, quantitative polymerase chain reaction, and next-generation sequencing. The use of more complex models with advanced assessment methodologies, subject to the availability of equipment/facilities, may help in developing clinically relevant biofilms and answering appropriate research questions.
Collapse
Affiliation(s)
- Srinivas Sulugodu Ramachandra
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- Preventive Dental Sciences, College of DentistryGulf Medical UniversityAjmanUnited Arab Emirates
| | - Patricia Wright
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
| | - Pingping Han
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
| | - Abdalla Abdal‐hay
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- Department of Engineering Materials and Mechanical Design, Faculty of EngineeringSouth Valley UniversityQenaEgypt
- Faculty of Industry and Energy Technology, Mechatronics Technology ProgramNew Cairo Technological University, New Cairo‐Fifth SettlementCairoEgypt
| | - Ryan S. B. Lee
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
| | - Saso Ivanovski
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
| |
Collapse
|
8
|
Cabezas-Mera FS, Atiencia-Carrera MB, Villacrés-Granda I, Proaño AA, Debut A, Vizuete K, Herrero-Bayo L, Gonzalez-Paramás AM, Giampieri F, Abreu-Naranjo R, Tejera E, Álvarez-Suarez JM, Machado A. Evaluation of the polyphenolic profile of native Ecuadorian stingless bee honeys ( Tribe: Meliponini) and their antibiofilm activity on susceptible and multidrug-resistant pathogens: An exploratory analysis. Curr Res Food Sci 2023; 7:100543. [PMID: 37455680 PMCID: PMC10344713 DOI: 10.1016/j.crfs.2023.100543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/08/2023] [Accepted: 06/27/2023] [Indexed: 07/18/2023] Open
Abstract
Biofilms are associated with infections that are resistant to conventional therapies, contributing to the antimicrobial resistance crisis. The need for alternative approaches against biofilms is well-known. Although natural products like stingless bee honeys (tribe: Meliponini) constitute an alternative treatment, much is still unknown. Our main goal was to evaluate the antibiofilm activity of stingless bee honey samples against multidrug-resistant (MDR) pathogens through biomass assays, fluorescence (cell count and viability), and scanning electron (structural composition) microscopy. We analyzed thirty-five honey samples at 15% (v/v) produced by ten different stingless bee species (Cephalotrigona sp., Melipona sp., M. cramptoni, M. fuscopilosa, M. grandis, M. indecisa, M. mimetica, M. nigrifacies, Scaptotrigona problanca, and Tetragonisca angustula) from five provinces of Ecuador (Tungurahua, Pastaza, El Oro, Los Ríos, and Loja) against 24-h biofilms of Staphylococcus aureus, Klebsiella pneumoniae, Candida albicans, and Candida tropicalis. The present honey set belonged to our previous study, where the samples were collected in 2018-2019 and their physicochemical parameters, chemical composition, mineral elements, and minimal inhibitory concentration (MIC) were screened. However, the polyphenolic profile and their antibiofilm activity on susceptible and multidrug-resistant pathogens were still unknown. According to polyphenolic profile of the honey samples, significant differences were observed according to their geographical origin in terms of the qualitative profiles. The five best honey samples (OR24.1, LR34, LO40, LO48, and LO53) belonging to S. problanca, Melipona sp., and M. indecisa were selected for further analysis due to their high biomass reduction values, identification of the stingless bee specimens, and previously reported physicochemical parameters. This subset of honey samples showed a range of 63-80% biofilm inhibition through biomass assays. Fluorescence microscopy (FM) analysis evidenced statistical log reduction in the cell count of honey-treated samples in all pathogens (P <0.05), except for S. aureus ATCC 25923. Concerning cell viability, C. tropicalis, K. pneumoniae ATCC 33495, and K. pneumoniae KPC significantly decreased (P <0.01) by 21.67, 25.69, and 45.62%, respectively. Finally, scanning electron microscopy (SEM) analysis demonstrated structural biofilm disruption through cell morphological parameters (such as area, size, and form). In relation to their polyphenolic profile, medioresinol was only found in the honey of Loja, while scopoletin, kaempferol, and quercetin were only identified in honey of Los Rios, and dihydrocaffeic and dihydroxyphenylacetic acids were only detected in honey of El Oro. All the five honey samples showed dihydrocoumaroylhexose, luteolin, and kaempferol rutinoside. To the authors' best knowledge, this is the first study to analyze stingless bees honey-treated biofilms of susceptible and/or MDR strains of S. aureus, K. pneumoniae, and Candida species.
Collapse
Affiliation(s)
- Fausto Sebastián Cabezas-Mera
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Instituto de Microbiología, Laboratorio de Bacteriología, Calle Diego de Robles y Pampite, Quito, 170901, Ecuador
| | - María Belén Atiencia-Carrera
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Instituto de Microbiología, Laboratorio de Bacteriología, Calle Diego de Robles y Pampite, Quito, 170901, Ecuador
| | - Irina Villacrés-Granda
- Programa de Doctorado Interuniversitario en Ciencias de la Salud, Universidad de Sevilla, Sevilla, Spain
- Facultad de Ingeniería y Ciencias Agropecuarias Aplicadas, Grupo de Bioquimioinformática, Universidad de Las Américas (UDLA), De Los Colimes esq, Quito, 170513, Quito, Ecuador
| | - Adrian Alexander Proaño
- Laboratorios de Investigación, Universidad de Las Américas (UDLA), Vía a Nayón, Quito, 170124, Ecuador
| | - Alexis Debut
- Departamento de Ciencias de la Vida y la Agricultura, Universidad de las Fuerzas Armadas ESPE, Sangolquí, 171103, Ecuador
- Centro de Nanociencia y Nanotecnología, Universidad de Las Fuerzas Armadas ESPE, Sangolquí, 171103, Ecuador
| | - Karla Vizuete
- Centro de Nanociencia y Nanotecnología, Universidad de Las Fuerzas Armadas ESPE, Sangolquí, 171103, Ecuador
| | - Lorena Herrero-Bayo
- Grupo de Investigación en Polifenoles (GIP-USAL), Universidad de Salamanca, Campus Miguel de Unamuno, 37008, Salamanca, Spain
| | - Ana M. Gonzalez-Paramás
- Grupo de Investigación en Polifenoles (GIP-USAL), Universidad de Salamanca, Campus Miguel de Unamuno, 37008, Salamanca, Spain
| | - Francesca Giampieri
- Research Group on Food, Nutritional Biochemistry and Health, Universidad Europea del Atlántico, C. Isabel Torres, 21, 39011, Santander, Cantabria, Spain
| | - Reinier Abreu-Naranjo
- Departamento de Ciencias de La Vida, Universidad Estatal Amazónica, Puyo, 160150, Ecuador
| | - Eduardo Tejera
- Facultad de Ingeniería y Ciencias Agropecuarias Aplicadas, Grupo de Bioquimioinformática, Universidad de Las Américas (UDLA), De Los Colimes esq, Quito, 170513, Quito, Ecuador
| | - José M. Álvarez-Suarez
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias e Ingenierías, Departamento de Ingeniería en Alimentos, Calle Diego de Robles y Pampite, Quito, 170901, Ecuador
| | - António Machado
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Instituto de Microbiología, Laboratorio de Bacteriología, Calle Diego de Robles y Pampite, Quito, 170901, Ecuador
| |
Collapse
|
9
|
Usta SN, Solana C, Ruiz-Linares M, Baca P, Ferrer-Luque CM, Cabeo M, Arias-Moliz MT. Effectiveness of conservative instrumentation in root canal disinfection. Clin Oral Investig 2023; 27:3181-3188. [PMID: 36867258 PMCID: PMC10264279 DOI: 10.1007/s00784-023-04929-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 02/22/2023] [Indexed: 03/04/2023]
Abstract
OBJECTIVES The impact of conservative instrumentation on the disinfection of root canals with different curvatures has not yet been determined. This ex vivo study aimed to evaluate and compare the effect of conservative instrumentation with TruNatomy (TN) and Rotate and a conventional rotary system, ProTaper Gold (PTG), on root canal disinfection during chemomechanical preparation of straight and curved canals. MATERIALS AND METHODS Ninety mandibular molars with straight (n = 45) and curved (n = 45) mesiobuccal root canals were contaminated with polymicrobial clinical samples. Teeth were divided into three subgroups (n = 14) according to the file systems and the curvature. Canals were instrumented with TN, Rotate, and PTG, respectively. Sodium hypochlorite and EDTA were used as irrigants. Intracanal samples were taken before (S1) and after (S2) instrumentation. Six uninfected teeth were used as negative controls. The bacterial reduction between S1 and S2 was measured by ATP assay, flow cytometry, and culture methods. Kruskal-Wallis and ANOVA tests were followed by the Duncan post hoc test (p < 0.05). RESULTS Bacterial reduction percentages were similar for the three file systems in straight canals (p > 0.05). However, PTG showed a lower reduction percentage of intact membrane cells in flow cytometry than TN and Rotate (p = 0.036). For the curved canals, no significant differences were obtained (p > 0.05). CONCLUSION Conservative instrumentation of straight and curved canals using TN and Rotate files resulted in similar bacterial reduction compared to PTG. CLINICAL RELEVANCE The disinfection efficacy of conservative instrumentation is similar to conventional instrumentation in straight and curved root canals.
Collapse
Affiliation(s)
- Sıla Nur Usta
- Department of Endodontics, Gulhane Faculty of Dentistry, University of Health Sciences, Etlik, Keçiören, 06018 Ankara Turkey
| | - Carmen Solana
- Department of Stomatology, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo S/N., 18071 Granada, Spain
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Granada, Spain
| | - Matilde Ruiz-Linares
- Department of Stomatology, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo S/N., 18071 Granada, Spain
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Granada, Spain
| | - Pilar Baca
- Department of Stomatology, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo S/N., 18071 Granada, Spain
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Granada, Spain
| | - Carmen María Ferrer-Luque
- Department of Stomatology, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo S/N., 18071 Granada, Spain
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Granada, Spain
| | - Monica Cabeo
- Department of Microbiology, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo S/N., 18071 Granada, Spain
| | - Maria Teresa Arias-Moliz
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Granada, Spain
- Department of Microbiology, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo S/N., 18071 Granada, Spain
| |
Collapse
|
10
|
Altun N, Hervello MF, Lombó F, González P. Using staining as reference for spectral imaging: Its application for the development of an analytical method to predict the presence of bacterial biofilms. Talanta 2023; 261:124655. [PMID: 37196402 DOI: 10.1016/j.talanta.2023.124655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/25/2023] [Accepted: 05/05/2023] [Indexed: 05/19/2023]
Abstract
At present, although spectral imaging is known to have a great potential to provide a massive amount of valuable information, the lack of reference methods remains as one of the bottlenecks to access the full capacity of this technique. This work aims to present a staining-based reference method with digital image treatment for spectral imaging, in order to propose a fast, efficient, contactless and non-invasive analytical method to predict the presence of biofilms. Spectral images of Pseudomonasaeruginosa biofilms formed on high density polyethylene coupons were acquired in visible and near infrared (vis-NIR) range between 400 and 1000 nm. Crystal violet staining served as a biofilm indicator, allowing the bacterial cells and the extracellular matrix to be marked on the coupon. Treated digital images of the stained biofilms were used as a reference. The size and pixels of the hyperspectral and digital images were scaled and matched to each other. Intensity color thresholds were used to differentiate the pixels associate to areas containing biofilms from those ones placed in biofilm-free areas. The model facultative Gram-negative bacterium, P. aeruginosa, which can form highly irregularly shaped and heterogeneous biofilm structures, was used to enhance the strength of the method, due to its inherent difficulties. The results showed that the areas with high and low intensities were modeled with good performance, but the moderate intensity areas (with potentially weak or nascent biofilms) were quite challenging. Image processing and artificial neural networks (ANN) methods were performed to overcome the issues resulted from biofilm heterogeneity, as well as to train the spectral data for biofilm predictions.
Collapse
Affiliation(s)
- Nazan Altun
- ASINCAR Agrifood Technology Center, Spain; Research Unit "Biotechnology in Nutraceuticals and Bioactive Compounds-BIONUC", Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, Oviedo, Spain; Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | | | - Felipe Lombó
- Research Unit "Biotechnology in Nutraceuticals and Bioactive Compounds-BIONUC", Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, Oviedo, Spain; Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain.
| | | |
Collapse
|
11
|
Fatima H, Bhattacharya A, Khare SK. Efficient remediation of meropenem using Bacillus tropicus EMB20 β-lactamase immobilized on magnetic nanoparticles. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 329:117054. [PMID: 36549054 DOI: 10.1016/j.jenvman.2022.117054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Reducing antibiotic pollution in the environment in essential to preserve the effectiveness of the available antibiotics. In the present study, β-lactamase from Bacillus tropicus EMB20 was immobilized onto magnetic nanoparticles (Fe3O4) through covalent coupling method. The nanoconjugate was structurally characterized using SEM, FTIR, UV-spectrometry, and XRD diffraction analyses. The prepared enzyme nanoconjugate was thereafter used for remediation of meropenem (Mer) and showed complete removal of 10 mgL-1 Mer within 3 h of treatment. Moreover, the immobilized enzyme was successfully recovered and reused for up to 5 cycles with 57% removal efficiency. The immobilized preparation was also observed to be effective in the removal of higher Mer concentrations of 25 and 50 mgL-1 with 79% and 75% removal efficiency, respectively. The major hydrolyzed product of Mer was found to be opened-lactam ring structure with m/z 402.16. The hydrolyzed product(s) were observed to be non-toxic as revealed through microbial MTT, confocal microscopy, and growth studies. Under the mixed conditions of 50 mgL-1 ampicillin (Amp), 10 mgL-1 amoxicillin (Amox) and, Mer, the nanoconjugate showed simultaneous complete removal of Amp and Mer, while 49% Amox removal was detected after 3 h of treatment. Moreover, the nanoconjugates also showed concomitant complete removal of antibiotic mixture with in 2 h from aquaculture wastewater. Overall, the study comes out with an efficient approach for remediation of β-lactam antibiotics from contaminated systems.
Collapse
Affiliation(s)
- Huma Fatima
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, India
| | - Amrik Bhattacharya
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, India
| | - Sunil Kumar Khare
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, India.
| |
Collapse
|
12
|
Aguilera FR, Viñas M, Sierra JM, Vinuesa T, R. Fernandez de Henestrosa A, Furmanczyk M, Trullàs C, Jourdan E, López-López J, Jorba M. Substantivity of mouth-rinse formulations containing cetylpyridinium chloride and O-cymen-5-ol: a randomized-crossover trial. BMC Oral Health 2022; 22:646. [PMID: 36575444 PMCID: PMC9793821 DOI: 10.1186/s12903-022-02688-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The efficacy of mouth-rinses strongly depends upon their substantivity. The use of natural and non-toxic products that avoid secondary effects is gaining interest in preventive dentistry. The purpose of this study was to evaluate the substantivity of two formulations of mouth-washing solutions based on cetylpyridinium (CPC) and O-cymen-5-ol. METHODS This was a randomized, double-blind, crossover trial conducted at the Faculty of Medicine and Health Sciences of the University of Barcelona. Bacterial re-colonization was followed by live/dead (SYTOTM9 + propidium iodide) bacterial staining and measured by confocal laser scanning microscopy and fluorometry. Unstimulated saliva samples were collected from 16 healthy individuals at baseline saliva and then, at 15 min, 30 min and 1, 2, 3, and 4 h after the following mouth-rinses: (i) a single, 1-min mouth-rinse with 15 ml of placebo (negative control); (ii) a single, 1-min mouth-rinse with 15 ml of CPC (0.05%) ; (iii) a single, 1-min mouth-rinse with 15 ml of O-cymen-5-ol (0.09%); (iv) a single, 1-min mouth-rinse with 15 ml of CPC (0.05%) + O-cymen-5-ol (0.09%). RESULTS Proportion of dead bacteria was significantly higher for all mouthrinses during the first 15 min compared to baseline (CPC = 48.0 ± 13.9; 95% CI 40.98-56.99; p < 0.001, O-cymen-5-ol = 79.8 ± 21.0; 95% CI 67.71-91.90; p < 0.05, CPC + O-cymen-5-ol = 49.4 ± 14; 95% CI 40.98-56.99; p < 0.001 by fluorometry and 54.8 ± 23.0; 95% CI 41.50-68.06; p < 0.001, 76.3 ± 17.1; 95% CI 66.36-86.14; p < 0.001, 47.4 ± 11.9; 95% CI 40.49-54.30; p < 0.001 by confocal laser scanning microscopy, respectively). Nevertheless, after 4 h, CPC + O-cymen-5-ol was the only one that obtained significant values as measured by the two quantification methods used (80.3 ± 22.8; 95% CI 67.15-93.50; p < 0.05 and 81.4 ± 13.8; 95% CI 73.45-89.43; p < 0.05). The combined use of CPC + O-cymen-5-ol increased the substantivity of the mouthrinse with respect to mouthrinses prepared with either of the two active products alone. CONCLUSION The synergistic interaction of CPC and O-cymen-5-ol prolongs their substantivity. The resulting formulation may be as effective as other antimicrobials, such as triclosan or chlorhexidine, but without their undesirable secondary effects. Thus, mouthrinsing products based on Combinations of CPC and O-cymen-5-ol may replace in the near future Triclosan and Chlorhexidine-based mouthrinses.
Collapse
Affiliation(s)
- Felipe-Rodrigo Aguilera
- grid.5841.80000 0004 1937 0247Laboratory of Molecular Microbiology and Antimicrobials, Department of Pathology and Experimental Therapeutics, Faculty of Medicine, University of Barcelona & IDIBELL, 08907 L’Hospitalet de Llobregat, Barcelona, Spain ,grid.7119.e0000 0004 0487 459XDental School, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile
| | - Miguel Viñas
- grid.5841.80000 0004 1937 0247Laboratory of Molecular Microbiology and Antimicrobials, Department of Pathology and Experimental Therapeutics, Faculty of Medicine, University of Barcelona & IDIBELL, 08907 L’Hospitalet de Llobregat, Barcelona, Spain
| | - Josep M. Sierra
- grid.5841.80000 0004 1937 0247Laboratory of Molecular Microbiology and Antimicrobials, Department of Pathology and Experimental Therapeutics, Faculty of Medicine, University of Barcelona & IDIBELL, 08907 L’Hospitalet de Llobregat, Barcelona, Spain
| | - Teresa Vinuesa
- grid.5841.80000 0004 1937 0247Laboratory of Molecular Microbiology and Antimicrobials, Department of Pathology and Experimental Therapeutics, Faculty of Medicine, University of Barcelona & IDIBELL, 08907 L’Hospitalet de Llobregat, Barcelona, Spain
| | | | - Marta Furmanczyk
- grid.487221.a0000 0004 1795 1224Innovation and Development, ISDIN, Barcelona, Spain
| | - Carles Trullàs
- grid.487221.a0000 0004 1795 1224Innovation and Development, ISDIN, Barcelona, Spain
| | - Eric Jourdan
- grid.487221.a0000 0004 1795 1224Innovation and Development, ISDIN, Barcelona, Spain
| | - José López-López
- grid.5841.80000 0004 1937 0247Department of Dentistry, Faculty of Medicine, University of Barcelona & IDIBELL, Barcelona, Spain
| | - Marta Jorba
- grid.5841.80000 0004 1937 0247Laboratory of Molecular Microbiology and Antimicrobials, Department of Pathology and Experimental Therapeutics, Faculty of Medicine, University of Barcelona & IDIBELL, 08907 L’Hospitalet de Llobregat, Barcelona, Spain
| |
Collapse
|
13
|
Cai X, Orsi M, Capecchi A, Köhler T, van Delden C, Javor S, Reymond JL. An intrinsically disordered antimicrobial peptide dendrimer from stereorandomized virtual screening. CELL REPORTS. PHYSICAL SCIENCE 2022; 3:101161. [PMID: 36632208 PMCID: PMC9780108 DOI: 10.1016/j.xcrp.2022.101161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/21/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Membrane-disruptive amphiphilic antimicrobial peptides behave as intrinsically disordered proteins by being unordered in water and becoming α-helical in contact with biological membranes. We recently discovered that synthesizing the α-helical antimicrobial peptide dendrimer L-T25 ((KL)8(KKL)4(KLL)2 KKLL) using racemic amino acids to form stereorandomized sr-T25, an analytically pure mixture of all possible diastereoisomers of L-T25, preserved antibacterial activity but abolished hemolysis and cytotoxicity, pointing to an intrinsically disordered antibacterial conformation and an α-helical cytotoxic conformation. In this study, to identify non-toxic intrinsically disordered homochiral antimicrobial peptide dendrimers (AMPDs), we surveyed sixty-three sr-analogs of sr-T25 selected by virtual screening. One of the analogs, sr-X18 ((KL)8(KLK)4(KLL)2 KLLL), lost antibacterial activity as L-enantiomer and became hemolytic due to α-helical folding. By contrast, the L- and D-enantiomers of sr-X22 ((KL)8(KL)4(KKLL)2 KLKK) were equally antibacterial, non-hemolytic, and non-toxic, implying an intrinsically disordered bioactive conformation. Screening stereorandomized libraries may be generally useful to identify or optimize intrinsically disordered bioactive peptides.
Collapse
Affiliation(s)
- Xingguang Cai
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Markus Orsi
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Alice Capecchi
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Thilo Köhler
- Department of Microbiology and Molecular Medicine, University of Geneva, Service of Infectious Diseases, University Hospital of Geneva, Geneva, Switzerland
| | - Christian van Delden
- Department of Microbiology and Molecular Medicine, University of Geneva, Service of Infectious Diseases, University Hospital of Geneva, Geneva, Switzerland
| | - Sacha Javor
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| |
Collapse
|
14
|
Krasowski G, Migdał P, Woroszyło M, Fijałkowski K, Chodaczek G, Czajkowska J, Dudek B, Nowicka J, Oleksy-Wawrzyniak M, Kwiek B, Paleczny J, Brożyna M, Junka A. The Assessment of Activity of Antiseptic Agents against Biofilm of Staphylococcus aureus Measured with the Use of Processed Microscopic Images. Int J Mol Sci 2022; 23:ijms232113524. [PMID: 36362310 PMCID: PMC9658380 DOI: 10.3390/ijms232113524] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 10/31/2022] [Accepted: 11/03/2022] [Indexed: 11/06/2022] Open
Abstract
Staphylococcal biofilms are major causative factors of non-healing wound infections. Their treatment algorithms recommend the use of locally applied antiseptic agents to counteract the spread of infection. The efficacy of antiseptics against biofilm is assessed in vitro by a set of standard quantitative and semi-quantitative methods. The development of software for image processing additionally allowed for the obtainment of quantitative data from microscopic images of biofilm dyed with propidium iodine and SYTO-9 reagents, differentiating dead cells from live ones. In this work, the method of assessment of the impact of antiseptic agents on staphylococcal biofilm in vitro, based on biofilms’ processed images, was proposed and scrutinized with regard to clinically relevant antiseptics, polyhexanide, povidone–iodine and hypochlorite. The standard quantitative culturing method was applied to validate the obtained data from processed images. The results indicated significantly higher activity of polyhexanide and povidone–iodine than hypochlorite against staphylococcal biofilm. Taking into account the fact that in vitro results of the efficacy of antiseptic agents against staphylococcal biofilm are frequently applied to back up their use in hospitals and ambulatory units, our work should be considered an important tool; providing reliable, quantitative data in this regard.
Collapse
Affiliation(s)
| | - Paweł Migdał
- Department of Environment Hygiene and Animal Welfare, Wroclaw University of Environmental and Life Sciences, 25 C.K. Norwida St., 51-630 Wroclaw, Poland
| | - Marta Woroszyło
- Department of Microbiology and Biotechnology, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology in Szczecin, Piastów 45, 70-311 Szczecin, Poland
| | - Karol Fijałkowski
- Department of Microbiology and Biotechnology, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology in Szczecin, Piastów 45, 70-311 Szczecin, Poland
| | - Grzegorz Chodaczek
- Bioimaging Laboratory, Łukasiewicz Research Network—PORT Polish Center for Technology Development, 54-066 Wrocław, Poland
| | - Joanna Czajkowska
- Laboratory of Microbiology, Łukasiewicz Research Network–PORT Polish Center for Technology Development, 54-066 Wrocław, Poland
| | - Bartłomiej Dudek
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Stanisława Przybyszewskiego 63, 51-148 Wrocław, Poland
| | - Joanna Nowicka
- Department of Microbiology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | - Monika Oleksy-Wawrzyniak
- Department of Pharmaceutical Microbiology and Parasitology, Faculty of Pharmacy Wrocław Medical University, 50-556 Wrocław, Poland
| | - Bartłomiej Kwiek
- Faculty of Medicine, Lazarski University, 02-662 Warszawa, Poland
| | - Justyna Paleczny
- Department of Pharmaceutical Microbiology and Parasitology, Faculty of Pharmacy Wrocław Medical University, 50-556 Wrocław, Poland
| | - Malwina Brożyna
- Department of Pharmaceutical Microbiology and Parasitology, Faculty of Pharmacy Wrocław Medical University, 50-556 Wrocław, Poland
| | - Adam Junka
- Department of Pharmaceutical Microbiology and Parasitology, Faculty of Pharmacy Wrocław Medical University, 50-556 Wrocław, Poland
- Correspondence:
| |
Collapse
|
15
|
Alcolombri U, Pioli R, Stocker R, Berry D. Single-cell stable isotope probing in microbial ecology. ISME COMMUNICATIONS 2022; 2:55. [PMID: 37938753 PMCID: PMC9723680 DOI: 10.1038/s43705-022-00142-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/10/2022] [Accepted: 06/09/2022] [Indexed: 05/30/2023]
Abstract
Environmental and host-associated microbiomes are typically diverse assemblages of organisms performing myriad activities and engaging in a network of interactions that play out in spatially structured contexts. As the sum of these activities and interactions give rise to overall microbiome function, with important consequences for environmental processes and human health, elucidating specific microbial activities within complex communities is a pressing challenge. Single-cell stable isotope probing (SC-SIP) encompasses multiple techniques that typically utilize Raman microspectroscopy or nanoscale secondary ion mass spectrometry (NanoSIMS) to enable spatially resolved tracking of isotope tracers in cells, cellular components, and metabolites. SC-SIP techniques are uniquely suited for illuminating single-cell activities in microbial communities and for testing hypotheses about cellular functions generated for example from meta-omics datasets. Here, we illustrate the insights enabled by SC-SIP techniques by reviewing selected applications in microbiology and offer a perspective on their potential for future research.
Collapse
Affiliation(s)
- Uria Alcolombri
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Roberto Pioli
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Roman Stocker
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland.
| | - David Berry
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
| |
Collapse
|
16
|
Belleville P, Merlin G, Ramousse J, Deseure J. Characterization of spatiotemporal electroactive anodic biofilm activity distribution using 1D simulations. Sci Rep 2022; 12:5849. [PMID: 35393459 PMCID: PMC8990003 DOI: 10.1038/s41598-022-09596-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 03/14/2022] [Indexed: 11/17/2022] Open
Abstract
Activity distribution limitation in electroactive biofilm remains an unclear phenomenon. Some observations using confocal microscopy have shown notable difference between activity close to the anode and activity at the liquid interface. A numerical model is developed in this work to describe biofilm growth and local biomass segregation in electroactive biofilm. Under our model hypothesis, metabolic activity distribution in the biofilm results from the competition between two limiting factors: acetate diffusion and electronic conduction in the biofilm. Influence of inactive biomass fraction (i.e. non-growing biomass fraction) properties (such as conductivity and density) is simulated to show variation in local biomass distribution. Introducing a dependence of effective diffusion to local density leads to a drastic biomass fraction segregation. Increasing density of inactive fraction reduces significantly acetate diffusion in biofilm, enhances biomass activity on the outer layer (liquid/biofilm interface) and maintains inner core largely inactive. High inactive fraction conductivity enhances biomass activity in the outer layer and enhances current production. Hence, investment in extracellular polymer substance (EPS), anchoring redox components, is benefit for biofilm electroactivity. However, under our model hypothesis it means that conductivity should be two order lower than biofilm conductivity reported in order to observe inner core active biomass segregation.
Collapse
Affiliation(s)
- Pierre Belleville
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, Grenoble INP Institute of Engineering, LEPMI, 38000, Grenoble, France.,Univ. Savoie Mont-Blanc, CNRS, LOCIE, UMR 5271, Polytech Annecy, Chambéry, bât. Helios, 60 rue du lac Léman, Savoie Technolac, 73370, Le Bourget du Lac, France
| | - Gerard Merlin
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, Grenoble INP Institute of Engineering, LEPMI, 38000, Grenoble, France.,Univ. Savoie Mont-Blanc, CNRS, LOCIE, UMR 5271, Polytech Annecy, Chambéry, bât. Helios, 60 rue du lac Léman, Savoie Technolac, 73370, Le Bourget du Lac, France
| | - Julien Ramousse
- Univ. Savoie Mont-Blanc, CNRS, LOCIE, UMR 5271, Polytech Annecy, Chambéry, bât. Helios, 60 rue du lac Léman, Savoie Technolac, 73370, Le Bourget du Lac, France
| | - Jonathan Deseure
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, Grenoble INP Institute of Engineering, LEPMI, 38000, Grenoble, France.
| |
Collapse
|
17
|
Biofilm on Toothbrushes of Children with Cystic Fibrosis: A Potential Source of Lung Re-Infection after Antibiotic Treatment? MATERIALS 2022; 15:ma15062139. [PMID: 35329591 PMCID: PMC8955218 DOI: 10.3390/ma15062139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 03/11/2022] [Accepted: 03/11/2022] [Indexed: 02/04/2023]
Abstract
Frequent recurrent lung infections result in irreversible lung damage in children with cystic fibrosis (CF). This study aimed to determine if toothbrushes contain biofilms of pathogens, and act as potential reservoirs for lung re-infection following antibiotic treatment of acute exacerbations. Toothbrushes were collected from children with CF of lung infection before, during and after antibiotic treatment. Toothbrushes were rinsed with sterile saline and cultured. Bacterial isolates from toothbrushes were identified by 16s rRNA gene sequencing and compared with isolates from a sputum sample of the same patient. Scanning electron microscopy (SEM) was used to visually confirm the presence of bacterial biofilms and confocal laser scanning microscopy (CLSM) combined with Live/Dead stain to confirm bacterial viability. Large numbers of bacteria and biofilms were present on all toothbrushes. SEM confirmed the presence of biofilms and CLSM confirmed bacterial viability on all toothbrushes. Pathogens identified on toothbrushes from children before and during antibiotics treatment were in concordance with the species found in sputum samples. Pseudomonas aeruginosa and Staphylococcus aureus was able to be cultured from children’s toothbrushes despite antibiotic treatment. Toothbrushes were shown to be contaminated with viable pathogens and biofilms before and during antibiotic treatment and could be a potential source of lung re-infections.
Collapse
|
18
|
Boutsioukis C, Arias-Moliz MT, Chávez de Paz LE. A critical analysis of research methods and experimental models to study irrigants and irrigation systems. Int Endod J 2022; 55 Suppl 2:295-329. [PMID: 35171506 PMCID: PMC9314845 DOI: 10.1111/iej.13710] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 02/07/2022] [Accepted: 02/08/2022] [Indexed: 11/28/2022]
Abstract
Irrigation plays an essential role in root canal treatment. The purpose of this narrative review was to critically appraise the experimental methods and models used to study irrigants and irrigation systems and to provide directions for future research. Studies on the antimicrobial effect of irrigants should use mature multispecies biofilms grown on dentine or inside root canals and should combine at least two complementary evaluation methods. Dissolution of pulp tissue remnants should be examined in the presence of dentine and, preferably, inside human root canals. Micro-omputed tomography is currently the method of choice for the assessment of accumulated dentine debris and their removal. A combination of experiments in transparent root canals and numerical modeling is needed to address irrigant penetration. Finally, models to evaluate irrigant extrusion through the apical foramen should simulate the periapical tissues and provide quantitative data on the amount of extruded irrigant. Mimicking the in vivo conditions as close as possible and standardization of the specimens and experimental protocols are universal requirements irrespective of the surrogate endpoint studied. Obsolete and unrealistic models must be abandoned in favour of more appropriate and valid ones that have more direct application and translation to clinical Endodontics.
Collapse
Affiliation(s)
- C Boutsioukis
- Department of Endodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - M T Arias-Moliz
- Department of Microbiology, Faculty of Dentistry, University of Granada, Granada, Spain
| | | |
Collapse
|
19
|
Luo TL, Vanek ME, Gonzalez-Cabezas C, Marrs CF, Foxman B, Rickard AH. In vitro model systems for exploring oral biofilms: From single-species populations to complex multi-species communities. J Appl Microbiol 2022; 132:855-871. [PMID: 34216534 PMCID: PMC10505481 DOI: 10.1111/jam.15200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 06/05/2021] [Accepted: 06/29/2021] [Indexed: 12/13/2022]
Abstract
Numerous in vitro biofilm model systems are available to study oral biofilms. Over the past several decades, increased understanding of oral biology and advances in technology have facilitated more accurate simulation of intraoral conditions and have allowed for the increased generalizability of in vitro oral biofilm studies. The integration of contemporary systems with confocal microscopy and 16S rRNA community profiling has enhanced the capabilities of in vitro biofilm model systems to quantify biofilm architecture and analyse microbial community composition. In this review, we describe several model systems relevant to modern in vitro oral biofilm studies: the constant depth film fermenter, Sorbarod perfusion system, drip-flow reactor, modified Robbins device, flowcells and microfluidic systems. We highlight how combining these systems with confocal microscopy and community composition analysis tools aids exploration of oral biofilm development under different conditions and in response to antimicrobial/anti-biofilm agents. The review closes with a discussion of future directions for the field of in vitro oral biofilm imaging and analysis.
Collapse
Affiliation(s)
- Ting L. Luo
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Michael E. Vanek
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Carlos Gonzalez-Cabezas
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Carl F. Marrs
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Betsy Foxman
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Alexander H. Rickard
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| |
Collapse
|
20
|
Meire MA, van der Waal SV. A critical analysis of research methods and experimental models to study intracanal medicaments. Int Endod J 2022; 55 Suppl 2:330-345. [PMID: 35100452 DOI: 10.1111/iej.13694] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 01/26/2022] [Indexed: 12/01/2022]
Abstract
In order to ensure predictable decontamination of the root canal system, chemo-mechanical preparation of the root canal space is sometimes supplemented with the use of intracanal medication. As microbial control of the root canal space is fundamental to the resolution of apical periodontitis, root canal disinfection strategies haven been researched intensively. The use of intracanal medication as a supplementary step to the chemo-mechanical preparation of the root canal space is one of them. Because of the costs and limitations of clinical research it is relevant and common practice to first evaluate alternative or new root canal disinfection modalities in laboratory studies. This involves the simulation of a root canal infection in a laboratory model, on which different disinfection strategies can be tested. When modelling the infected root canal, different levels of infection can be discriminated: suspended bacteria, microbial biofilms and infected dentine. This review describes the experimental models associated with these infection levels and critically appraises their value and methodological details. Suggestions for relevant research methods and experimental models are given, as well as some good practices for laboratory-based microbiological studies.
Collapse
Affiliation(s)
- M A Meire
- Department of Oral Health Sciences, Section of Endodontology, Ghent University, Ghent, Belgium
| | - S V van der Waal
- Department of Endodontology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| |
Collapse
|
21
|
Castro J, Lima Â, Sousa LGV, Rosca AS, Muzny CA, Cerca N. Crystal Violet Staining Alone Is Not Adequate to Assess Synergism or Antagonism in Multi-Species Biofilms of Bacteria Associated With Bacterial Vaginosis. Front Cell Infect Microbiol 2022; 11:795797. [PMID: 35071046 PMCID: PMC8766793 DOI: 10.3389/fcimb.2021.795797] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/15/2021] [Indexed: 12/14/2022] Open
Abstract
Bacterial Vaginosis (BV) involves the presence of a multi-species biofilm adhered to vaginal epithelial cells, but its in-depth study has been limited due to the complexity of the bacterial community, which makes the design of in vitro models challenging. Perhaps the most common experimental technique to quantify biofilms is the crystal violet (CV) staining method. Despite its widespread utilization, the CV method is not without flaws. While biofilm CV quantification within the same strain in different conditions is normally accepted, assessing multi-species biofilms formation by CV staining might provide significant bias. For BV research, determining possible synergism or antagonism between species is a fundamental step for assessing the roles of individual species in BV development. Herein, we provide our perspective on how CV fails to properly quantify an in vitro triple-species biofilm composed of Gardnerella vaginalis, Fannyhessea (Atopobium) vaginae, and Prevotella bivia, three common BV-associated bacteria thought to play key roles in incident BV pathogenesis. We compared the CV method with total colony forming units (CFU) and fluorescence microscopy cell count methods. Not surprisingly, when comparing single-species biofilms, the relationship between biofilm biomass, total number of cells, and total cultivable cells was very different between each tested method, and also varied with the time of incubation. Thus, despite its wide utilization for single-species biofilm quantification, the CV method should not be considered for accurate quantification of multi-species biofilms in BV pathogenesis research.
Collapse
Affiliation(s)
- Joana Castro
- Centre of Biological Engineering (CEB), Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
| | - Ângela Lima
- Centre of Biological Engineering (CEB), Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
| | - Lúcia G V Sousa
- Centre of Biological Engineering (CEB), Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
| | - Aliona S Rosca
- Centre of Biological Engineering (CEB), Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
| | - Christina A Muzny
- Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Nuno Cerca
- Centre of Biological Engineering (CEB), Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
| |
Collapse
|
22
|
Sammarro Silva KJ, Sabogal-Paz LP. Analytical challenges and perspectives of assessing viability of Giardia muris cysts and Cryptosporidium parvum oocysts by live/dead simultaneous staining. ENVIRONMENTAL TECHNOLOGY 2022; 43:60-69. [PMID: 32463712 DOI: 10.1080/09593330.2020.1775712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
Giardia and Cryptosporidium are pathogenic protozoa often present in the environment in their infective form(cysts and oocysts). These parasites are very resistant to disinfection, which makes them important target organisms in environmental quality monitoring and sanitation. Viability assessment provides an interpretation of cell inactivation, and it can be evaluated by membrane integrity as well as enzyme activity, using different staining methods. These are straightforward and adequate to laboratories that lack infrastructure for molecular-based technologies or animal infectivity tests. This study investigated simultaneous staining by a commercial live/dead kit, in order to assess viability of Cryptosporidium parvum oocysts and Giardia muris cysts, comparing it to propidium iodide (PI) incorporation, a common stain applied in viability estimation. Results suggested that, although the central hypothesis of one-panel visualization (α = 0.05) was met, simultaneous staining impaired (oo)cyst detection by immunofluorescence assay (IFA), which was found to be essential to enumeration, as the live/dead test led to poor (oo)cyst labelling or a 10-fold lower recovery when carried out concomitantly to IFA. As for the viability assessment itself, although red dye uptake occurred as expected by dead or weakened organisms, neither live G. muris cysts or C. parvum oocysts present any green fluorescence by esterase metabolism. This may have been caused by low enzyme activity in the infective form and/or wall thickness of these parasites. The results do not exclude the possibility of simultaneous fluorescence staining for protozoa, but it is a starting point for a broader analysis, that may consider, for instance, different incubation conditions.
Collapse
Affiliation(s)
- Kamila Jessie Sammarro Silva
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, São Carlos, Brazil
| | - Lyda Patricia Sabogal-Paz
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, São Carlos, Brazil
| |
Collapse
|
23
|
Cunliffe AJ, Askew PD, Stephan I, Iredale G, Cosemans P, Simmons LM, Verran J, Redfern J. How Do We Determine the Efficacy of an Antibacterial Surface? A Review of Standardised Antibacterial Material Testing Methods. Antibiotics (Basel) 2021; 10:1069. [PMID: 34572650 PMCID: PMC8472414 DOI: 10.3390/antibiotics10091069] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 11/16/2022] Open
Abstract
Materials that confer antimicrobial activity, be that by innate property, leaching of biocides or design features (e.g., non-adhesive materials) continue to gain popularity to combat the increasing and varied threats from microorganisms, e.g., replacing inert surfaces in hospitals with copper. To understand how efficacious these materials are at controlling microorganisms, data is usually collected via a standardised test method. However, standardised test methods vary, and often the characteristics and methodological choices can make it difficult to infer that any perceived antimicrobial activity demonstrated in the laboratory can be confidently assumed to an end-use setting. This review provides a critical analysis of standardised methodology used in academia and industry, and demonstrates how many key methodological choices (e.g., temperature, humidity/moisture, airflow, surface topography) may impact efficacy assessment, highlighting the need to carefully consider intended antimicrobial end-use of any product.
Collapse
Affiliation(s)
- Alexander J. Cunliffe
- Department of Natural Sciences, Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK;
| | - Peter D. Askew
- (Industrial Microbiological Services Ltd.) IMSL, Pale Lane, Hartley Whitney, Hants RG27 8DH, UK; (P.D.A.); (G.I.)
| | - Ina Stephan
- (Bundesanstalt für Materialforschung und -prüfung) BAM, Unter den Eichen 87, 12205 Berlin, Germany;
| | - Gillian Iredale
- (Industrial Microbiological Services Ltd.) IMSL, Pale Lane, Hartley Whitney, Hants RG27 8DH, UK; (P.D.A.); (G.I.)
| | | | - Lisa M. Simmons
- Department of Engineering, Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK;
| | - Joanna Verran
- Department of Life Sciences, Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK;
| | - James Redfern
- Department of Natural Sciences, Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK;
| |
Collapse
|
24
|
Chen X, Bai K, Lyu Q, Jiang N, Li J, Luo L. Role of Penicillin-Binding Proteins in the Viability, Morphology, Stress Tolerance, and Pathogenicity of Clavibacter michiganensis. PHYTOPATHOLOGY 2021; 111:1301-1312. [PMID: 33369478 DOI: 10.1094/phyto-08-20-0326-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Previous research has shown that penicillin-binding proteins (PBPs), enzymes involved in peptidoglycan (PG) assembly, could play an important role during the induction of the viable but nonculturable (VBNC) state, which allows non-spore-forming bacteria to survive adverse environmental conditions. The current study found that Clavibacter michiganensis has seven PBPs. Mutant analysis indicated that deletion of either of the class B PBPs was lethal and that the class A PBPs had an important role in PG synthesis, with the ΔpbpC mutant having an altered cellular morphology that resulted in longer cells that were swollen at one end and had thinner cell walls. The ΔpbpC mutant was also found to produce mucoid colonies in solid culture and a lower final cell titer in liquid medium, as well as having high sensitivity to osmotic stress and lysozyme treatment and surprisingly high pathogenicity. The double mutant, ΔdacB/ΔpbpE, also had a slightly altered phenotype, resulting in longer cells. Further analysis revealed that both mutants had high sensitivity to copper, which resulted in quicker induction into the VBNC state. However, only the ΔpbpC mutant had significantly reduced survivorship in the VBNC state. The study also confirmed that the VBNC state significantly improved the survivorship of wild-type C. michiganensis cells in response to environmental stresses and systemically demonstrated the protective role of the VBNC state in C. michiganensis, which is an important finding regarding its epidemiology and has serious implications for disease management.
Collapse
Affiliation(s)
- Xing Chen
- Department of Plant Pathology, College of Plant Protection, China Agricultural University; Beijing Key Laboratory of Seed Disease Testing and Control, Beijing 100193, P.R. China
| | - Kaihong Bai
- Department of Plant Pathology, College of Plant Protection, China Agricultural University; Beijing Key Laboratory of Seed Disease Testing and Control, Beijing 100193, P.R. China
| | - Qingyang Lyu
- Department of Plant Pathology, College of Plant Protection, China Agricultural University; Beijing Key Laboratory of Seed Disease Testing and Control, Beijing 100193, P.R. China
- Key Laboratory of Environmental and Applied Microbiology, CAS, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, P.R. China
| | - Na Jiang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University; Beijing Key Laboratory of Seed Disease Testing and Control, Beijing 100193, P.R. China
| | - Jianqiang Li
- Department of Plant Pathology, College of Plant Protection, China Agricultural University; Beijing Key Laboratory of Seed Disease Testing and Control, Beijing 100193, P.R. China
| | - Laixin Luo
- Department of Plant Pathology, College of Plant Protection, China Agricultural University; Beijing Key Laboratory of Seed Disease Testing and Control, Beijing 100193, P.R. China
| |
Collapse
|
25
|
Antibacterial effect of silver nanoparticles mixed with calcium hydroxide or chlorhexidine on multispecies biofilms. Odontology 2021; 109:802-811. [PMID: 34047872 DOI: 10.1007/s10266-021-00601-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 03/15/2021] [Indexed: 10/21/2022]
Abstract
The purpose is to evaluate the antibacterial effects of the silver nanoparticles (AgNPs) (Nanografi, METU Teknokent, Ankara, Turkey) mixed with calcium hydroxide (Ca(OH)2) (Ultracal XS, Ultradent, St Louis, US) or chlorhexidine gel (CHX) (Gluco-Chex, Cerkamed, Stalowa Wola, Poland) against a multispecies biofilm, by confocal laser scanning microscopy (CLSM) and culture-based analysis. Dentine blocks were inoculated with Enterococcus faecalis, Streptococcus mutans, Lactobacillus acidophilus and Actinomyces naeslundii for 1 week. Infected dentine blocks were randomly divided into groups according to medication; saline solution (SS), Ca(OH)2, Ca(OH)2 + AgNP, 2%CHX gel and 2%CHX gel + AgNP and time of application: 1 and 7 days (all groups, n = 5). Bacterial samples were collected before and after medication to quantify the bacterial load. Biofilm elimination was quantitatively analyzed by Live/Dead BacLight Bacterial Viability staining and CLSM. The addition of AgNPs to Ca(OH)2 increased the effectiveness of medicament in terms of bacterial reduction in both application times (1 and 7 days) (p < 0.05: ANOVA, Tukey's test) according to culture-based analysis. The CLSM images revealed that mixture of AgNP with CHX killed significantly more bacteria when compared with all other medicaments at 1- and 7-day application times (p < 0.05 and p > 0.05, respectively: Kruskal-Wallis, Dunn post hoc tests). The efficacy of Ca(OH)2 mixed with AgNPs was superior to Ca(OH)2 used alone in both application times (p < 0.05) according to CLSM analysis. The present study put forth the potential use of AgNPs mixed with Ca(OH)2 or CHX on multispecies (Enterococcus faecalis, Streptococcus mutans, Lactobacillus acidophilus and Actinomyces naeslundii) biofilm in 1 and 7day application periods.
Collapse
|
26
|
Abstract
The human mouth harbors a complex microbiota, the composition of which is potentially influenced by a wide range of factors, including the intake of food and drink, the availability of endogenous nutrients, the host immune system, drug treatments, and systemic diseases. Despite these possible influences, the oral microbiota is remarkably resilient, particularly in comparison with the microbiota of the large intestine. Diet, with the exception of excessive and/or frequent consumption of fermentable carbohydrate or supplementation with nitrate, has minimal impact on the composition of the oral bacterial community. The common oral diseases dental caries and the periodontal diseases is associated with modification of the oral microbiota primarily as a result of the ecological changes induced by excessive acid production and inflammation, respectively. Systemically-administered antimicrobials have only a small effect on the composition of the oral bacterial community, and while locally delivered antimicrobials can have some clinical benefits, the biofilm lifestyle of oral bacteria lends them substantial resistance to the agents used. Saliva plays an important role in oral microbial ecology, by supplying nutrients and providing protection against colonization by nonoral organisms. Dry mouth is one condition that has a major effect on the microbiota, resulting in increased colonization by opportunistic pathogens. Some systemic diseases do affect the oral microbiome, notably diabetes, in which raised levels of glucose in saliva and tissue impact on bacterial nutrition.
Collapse
Affiliation(s)
- William G Wade
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, UK.,Department of Microbiology, Forsyth Institute, Cambridge, MA, USA
| |
Collapse
|
27
|
Sammarro Silva KJ, Sabogal-Paz LP. Cryptosporidium spp. and Giardia spp. (oo)cysts as target-organisms in sanitation and environmental monitoring: A review in microscopy-based viability assays. WATER RESEARCH 2021; 189:116590. [PMID: 33166919 DOI: 10.1016/j.watres.2020.116590] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/22/2020] [Accepted: 10/31/2020] [Indexed: 06/11/2023]
Abstract
Cysts and (oo)cysts are the infective forms of parasitic protozoa, as Giardia and Cryptosporidium, which are widespread and associated to worldwide waterborne diseases outbreaks. These microorganisms pose a challenge to public health, as they are resistant to conventional disinfection methods, which make them important parameters when evaluating inactivation efficiency. However, when (oo)cysts are targets, it is challenging to infer inactivation efficacy, as it may require infectivity tests that are not often an option for laboratory routine analysis. In this scene, (oo)cyst viability based on induced excystation, membrane integrity and enzyme activity evaluated by dye inclusion and/or exclusion, as well as fluorescence reduction consist on microscopy-based techniques that may be options to estimate inactivation in the environmental context. This scoping review presents applications, advantages and limitations of these methodologies for viability assessment, in order to shed light on the (oo)cyst viability topic and provide insight strategies for choosing protocols in the environmental and sanitation field, in laboratory applications and novel research.
Collapse
Affiliation(s)
- Kamila Jessie Sammarro Silva
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-carlense 400, São Carlos, São Paulo, 13566-590, Brazil
| | - Lyda Patricia Sabogal-Paz
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-carlense 400, São Carlos, São Paulo, 13566-590, Brazil.
| |
Collapse
|
28
|
Nielsen JE, Bjørnestad VA, Pipich V, Jenssen H, Lund R. Beyond structural models for the mode of action: How natural antimicrobial peptides affect lipid transport. J Colloid Interface Sci 2021; 582:793-802. [DOI: 10.1016/j.jcis.2020.08.094] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/21/2020] [Accepted: 08/25/2020] [Indexed: 12/18/2022]
|
29
|
Combatting fungal biofilm formation by diffusive release of fluconazole from heptylamine plasma polymer coating. Biointerphases 2020; 15:061012. [PMID: 33339460 DOI: 10.1116/6.0000511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A drug-eluting coating applied onto biomedical devices and implants is an appropriate way to ensure that an inhibitory concentration of antimicrobial drugs is present at the device surface, thus preventing surface colonization and subsequent biofilm formation. In this study, a thin polymer coating was applied to materials, and it acted as a drug-delivery reservoir capable of surface delivery of the antifungal drug fluconazole to amounts up to 21 μg/cm2. The release kinetics into aqueous solution were quantified by UV spectroscopy and conformed to the Ritger-Peppas and Korsmeyer-Peppas model. Complementary microbiological assays were used to determine effectiveness against Candida albicans attachment and biofilm formation, and against the control heptylamine plasma polymer coating without drug loading, on which substantial fungal growth occurred. Fluconazole release led to marked antifungal activity in all assays, with log 1.6 reduction in CFUs/cm2. Cell viability assays and microscopy revealed that fungal cells attached to the fluconazole-loaded coating remained rounded and did not form hyphae and biofilm. Thus, in vitro screening results for fluconazole-releasing surface coatings showed efficacy in the prevention of the formation of Candida albicans biofilm.
Collapse
|
30
|
Gan BH, Cai X, Javor S, Köhler T, Reymond JL. Synergistic Effect of Propidium Iodide and Small Molecule Antibiotics with the Antimicrobial Peptide Dendrimer G3KL against Gram-Negative Bacteria. Molecules 2020; 25:E5643. [PMID: 33266085 PMCID: PMC7730455 DOI: 10.3390/molecules25235643] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 12/22/2022] Open
Abstract
There is an urgent need to develop new antibiotics against multidrug-resistant bacteria. Many antimicrobial peptides (AMPs) are active against such bacteria and often act by destabilizing membranes, a mechanism that can also be used to permeabilize bacteria to other antibiotics, resulting in synergistic effects. We recently showed that G3KL, an AMP with a multibranched dendritic topology of the peptide chain, permeabilizes the inner and outer membranes of Gram-negative bacteria including multidrug-resistant strains, leading to efficient bacterial killing. Here, we show that permeabilization of the outer and inner membranes of Pseudomonas aeruginosa by G3KL, initially detected using the DNA-binding fluorogenic dye propidium iodide (PI), also leads to a synergistic effect between G3KL and PI in this bacterium. We also identify a synergistic effect between G3KL and six different antibiotics against the Gram-negative Klebsiella pneumoniae, against which G3KL is inactive.
Collapse
Affiliation(s)
- Bee-Ha Gan
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland; (B.-H.G.); (X.C.); (S.J.)
| | - Xingguang Cai
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland; (B.-H.G.); (X.C.); (S.J.)
| | - Sacha Javor
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland; (B.-H.G.); (X.C.); (S.J.)
| | - Thilo Köhler
- Department of Microbiology and Molecular Medicine, University of Geneva, 1211 Geneva, Switzerland;
- Service of Infectious Diseases, Geneva University Hospitals, 1211 Geneva, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland; (B.-H.G.); (X.C.); (S.J.)
| |
Collapse
|
31
|
Wright PP, Cooper C, Kahler B, Walsh LJ. Multiple assessment methodologies in determining the antibiofilm actions of sodium hypochlorite mixed with clodronate or etidronate in endodontic irrigation. J Microbiol Methods 2020; 180:106107. [PMID: 33227309 DOI: 10.1016/j.mimet.2020.106107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/28/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
This study aimed to use multiple methodologies, including a novel usage of scanning electron microscopy (SEM), to evaluate the antimicrobial actions of sodium hypochlorite (NaOCl) admixed with clodronate or etidronate in root canal irrigation. The study also examined the usefulness of colony counting as a biofilm assessment methodology. Seven day Enterococcus faecalis biofilms were grown on hydroxyapatite discs. The discs were disinfected with 0.26 M clodronate-5% NaOCl, 0.26 M etidronate-5% NaOCl, 5% NaOCl, or treated with phosphate buffered saline (PBS). Assessments were performed using colony counting, SEM and the XTT reduction assay. The XTT assessment used the same groups but with 2.5% NaOCl. For colony counting, bacteria were removed from the discs by vortex mixing, followed by plating. The discs were subsequently fixed for SEM imagining and evaluators scored the SEM micrographs for remaining bacteria. Antibiofilm actions were assessed with the Kruskal-Wallis and Dunn's multiple comparison tests. SEM micrographs and the XTT assay revealed no differences between the NaOCl controls and the clodronate or etidronate mixtures with NaOCl (P > 0.05). It was concluded that the chelator mixtures with NaOCl had antibiofilm actions comparable to NaOCl. Furthermore, vortex mixing incompletely removed biofilm from HA discs in the PBS controls and hence colony counting using E. faecalis biofilms on hydroxyapatite discs could not be used for intergroup comparisons involving PBS. Additionally, colony counting could not be used for comparisons between the NaOCl treatment groups because the removal of bacteria from the substrate by vortex mixing was affected by the irrigant type.
Collapse
Affiliation(s)
- Patricia P Wright
- University of Queensland, School of Dentistry, 288 Herston Rd, Herston, QLD, 4006, Australia.
| | - Crystal Cooper
- Central Analytical Research Facility (CARF), Institute for Future Environments, Queensland University of Technology, 2 George Street, Brisbane, 4000, Australia
| | - Bill Kahler
- University of Queensland, School of Dentistry, 288 Herston Rd, Herston, QLD, 4006, Australia
| | - Laurence J Walsh
- University of Queensland, School of Dentistry, 288 Herston Rd, Herston, QLD, 4006, Australia
| |
Collapse
|
32
|
Lindivat M, Larsen A, Hess-Erga OK, Bratbak G, Hoell IA. Bioorthogonal Non-canonical Amino Acid Tagging Combined With Flow Cytometry for Determination of Activity in Aquatic Microorganisms. Front Microbiol 2020; 11:1929. [PMID: 33013733 PMCID: PMC7461810 DOI: 10.3389/fmicb.2020.01929] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 07/22/2020] [Indexed: 11/13/2022] Open
Abstract
In this study, we have combined bioorthogonal non-canonical amino acid tagging (BONCAT) and flow cytometry (FCM) analysis, and we demonstrate the applicability of the method for marine prokaryotes. Enumeration of active marine bacteria was performed by combining the DNA stain SYBR Green with detection of protein production with BONCAT. After optimization of incubation condition and substrate concentration on monoculture of Escherichia coli, we applied and modified the method to natural marine samples. We found that between 10 and 30% of prokaryotes in natural communities were active. The method is replicable, fast, and allow high sample throughput when using FCM. We conclude that the combination of BONCAT and FCM is an alternative to current methods for quantifying active populations in aquatic environments.
Collapse
Affiliation(s)
- Mathilde Lindivat
- Faculty of Engineering and Science, Institute of Safety Chemistry and Biomedical Laboratory Sciences, Western Norway University of Applied Sciences, Haugesund, Norway
| | - Aud Larsen
- NORCE Environment, NORCE Norwegian Research Centre AS, Bergen, Norway.,Department of Biological Sciences, University of Bergen, Bergen, Norway
| | | | - Gunnar Bratbak
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Ingunn Alne Hoell
- Faculty of Engineering and Science, Institute of Safety Chemistry and Biomedical Laboratory Sciences, Western Norway University of Applied Sciences, Haugesund, Norway
| |
Collapse
|
33
|
Kreth J, Merritt J, Pfeifer C, Khajotia S, Ferracane J. Interaction between the Oral Microbiome and Dental Composite Biomaterials: Where We Are and Where We Should Go. J Dent Res 2020; 99:1140-1149. [PMID: 32479134 PMCID: PMC7443996 DOI: 10.1177/0022034520927690] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Dental composites are routinely placed as part of tooth restoration procedures. The integrity of the restoration is constantly challenged by the metabolic activities of the oral microbiome. This activity directly contributes to a less-than-desirable half-life for the dental composite formulations currently in use. Therefore, many new antimicrobial dental composites are being developed to counteract the microbial challenge. To ensure that these materials will resist microbiome-derived degradation, the model systems used for testing antimicrobial activities should be relevant to the in vivo environment. Here, we summarize the key steps in oral microbial colonization that should be considered in clinically relevant model systems. Oral microbial colonization is a clearly defined developmental process that starts with the formation of the acquired salivary pellicle on the tooth surface, a conditioned film that provides the critical attachment sites for the initial colonizers. Further development includes the integration of additional species and the formation of a diverse, polymicrobial mature biofilm. Biofilm development is discussed in the context of dental composites, and recent research is highlighted regarding the effect of antimicrobial composites on the composition of the oral microbiome. Future challenges are addressed, including the potential of antimicrobial resistance development and how this could be counteracted by detailed studies of microbiome composition and gene expression on dental composites. Ultimately, progress in this area will require interdisciplinary approaches to effectively mitigate the inevitable challenges that arise as new experimental bioactive composites are evaluated for potential clinical efficacy. Success in this area could have the added benefit of inspiring other fields in medically relevant materials research, since microbial colonization of medical implants and devices is a ubiquitous problem in the field.
Collapse
Affiliation(s)
- J. Kreth
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR, USA
| | - J. Merritt
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR, USA
| | - C.S. Pfeifer
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
| | - S. Khajotia
- Department of Restorative Sciences, College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - J.L. Ferracane
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
34
|
Yilmaz Ş, Yoldas O, Dumani A, Guler G, Ilgaz S, Akbal E, Oksuz H, Celik A, Yilmaz B. Calcium hypochlorite on mouse embryonic fibroblast cells (NIH3T3) in vitro cytotoxicity and genotoxicity: MTT and comet assay. Mol Biol Rep 2020; 47:5377-5383. [PMID: 32623618 DOI: 10.1007/s11033-020-05624-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 06/26/2020] [Indexed: 10/23/2022]
Abstract
Antimicrobial irrigation solutions are widely used under clinical settings. Their effect on dental tissue is a subject of recent research, which aims for a safer irrigant for clinical use. In this regard, here our goal was to evaluate the cytotoxicity and the genotoxicity of calcium hypochlorite (Ca(OCl)2) solution, along with NaOCl, on Mouse embryonic fibroblast cells (NIH3T3). First, Cells were treated either with NaOCl or Ca(OCl)2 in a time- and dose-dependent manner for cytotoxicity by 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, then cell viability was calculated according to cell proliferation plots. Secondly, genotoxicity was assessed by Comet assay. Data were statistically analyzed by Tukey's test (P < .05). NaOCl and Ca(OCl)2 had similar effects on cellular viability at 3 and 6 h treatments. Cell viability of Ca(OCl)2 at concentrations of 0.0125%, 0.025%, 0.05%, or 0.125% was significantly lower than that of NaOCl at 24 h treatment (P < .05).Comparing Ca(OCl)2 and NaOCl treatments at all time points and concentrations, the damaged cell number of Ca(OCl)2 was almost fourfold higher than that of NaOCl. In conclusion, both, NaOCl and Ca(OCl)2 solutions were cytotoxic and genotoxic to NIH3T3, however, Ca(OCl)2 had a significantly higher damaged cell percentage than NaOCl at all time points and concentrations investigated.
Collapse
Affiliation(s)
- Şehnaz Yilmaz
- Department of Endodontics, Faculty of Dentistry, Cukurova University, Adana, Turkey
| | - Oguz Yoldas
- Department of Endodontics, Faculty of Dentistry, Cukurova University, Adana, Turkey
| | - Aysin Dumani
- Department of Endodontics, Faculty of Dentistry, Cukurova University, Adana, Turkey
| | - Gizem Guler
- Department of Biology, Faculty of Science and Letters, Mersin University, Mersin, Turkey
| | - Seda Ilgaz
- Department of Medical Biology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Eylül Akbal
- Department of Medical Biology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Hale Oksuz
- Department of Medical Biology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Ayla Celik
- Department of Biology, Faculty of Science and Letters, Mersin University, Mersin, Turkey.
| | - Bertan Yilmaz
- Department of Medical Biology, Faculty of Medicine, Cukurova University, Adana, Turkey
| |
Collapse
|
35
|
Choi J, Baek J, Kweon D, Ko KS, Yoon H. Rapid determination of carbapenem resistance by low-cost colorimetric methods: Propidium Iodide and alamar blue staining. J Microbiol 2020; 58:415-421. [PMID: 32221821 DOI: 10.1007/s12275-020-9549-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/04/2020] [Accepted: 02/14/2020] [Indexed: 01/03/2023]
Abstract
Carbapenems are a class of β-lactam antibiotics with a broad antimicrobial activity spectrum. Owing to their sturdy structures resistant to most β-lactamases, they have been regarded as one of the last-resort antibiotics for combating multidrugresistant bacterial infections. However, the emergence of carbapenem resistance increases predominantly in nosocomial pathogens. To prevent spread of carbapenem resistance in early stages, it is imperative to develop rapid diagnostic tests that will substantially reduce the time and cost in determining carbapenem resistance. Thus, we devised a staining-based diagnostic method applicable to three different Gram-negative pathogens of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae, all with the high potential to develop carbapenem resistance. Regardless of the resistance mechanisms presented by bacterial species and strains, double staining with propidium iodide (PI) and alamar blue (AB) identified resistant bacteria with an average sensitivity of 95.35%, 7 h after imipenem treatments in 343 clinical isolates. Among the three species tested, A. baumannii showed the highest diagnostic sensitivity of 98.46%. The PI and ABmediated staining method could be a promising diagnostic method with high-throughput efficacy and low cost.
Collapse
Affiliation(s)
- Jiyoon Choi
- Department of Molecular Science and Technology, Ajou University, Suwon, 16499, Republic of Korea
| | - Jiwon Baek
- Department of Molecular Science and Technology, Ajou University, Suwon, 16499, Republic of Korea
| | - Daehyuk Kweon
- Department of Genetic Engineering and Center for Human Interface Nano Technology, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Kwan Soo Ko
- Department of Molecular Cell Biology, Sungkyunkwan University, School of Medicine, Suwon, 16419, Republic of Korea.,Asia-Pacific Research Foundation for Infectious Diseases, Seoul, 06367, Republic of Korea
| | - Hyunjin Yoon
- Department of Molecular Science and Technology, Ajou University, Suwon, 16499, Republic of Korea. .,Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon, 16499, Republic of Korea.
| |
Collapse
|
36
|
Hatzenpichler R, Krukenberg V, Spietz RL, Jay ZJ. Next-generation physiology approaches to study microbiome function at single cell level. Nat Rev Microbiol 2020; 18:241-256. [PMID: 32055027 DOI: 10.1038/s41579-020-0323-1] [Citation(s) in RCA: 144] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2020] [Indexed: 12/14/2022]
Abstract
The function of cells in their native habitat often cannot be reliably predicted from genomic data or from physiology studies of isolates. Traditional experimental approaches to study the function of taxonomically and metabolically diverse microbiomes are limited by their destructive nature, low spatial resolution or low throughput. Recently developed technologies can offer new insights into cellular function in natural and human-made systems and how microorganisms interact with and shape the environments that they inhabit. In this Review, we provide an overview of these next-generation physiology approaches and discuss how the non-destructive analysis of cellular phenotypes, in combination with the separation of the target cells for downstream analyses, provide powerful new, complementary ways to study microbiome function. We anticipate that the widespread application of next-generation physiology approaches will transform the field of microbial ecology and dramatically improve our understanding of how microorganisms function in their native environment.
Collapse
Affiliation(s)
- Roland Hatzenpichler
- Department of Chemistry and Biochemistry, Center for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA.
| | - Viola Krukenberg
- Department of Chemistry and Biochemistry, Center for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA
| | - Rachel L Spietz
- Department of Chemistry and Biochemistry, Center for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA
| | - Zackary J Jay
- Department of Chemistry and Biochemistry, Center for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA
| |
Collapse
|
37
|
Michl TD, Tran DTT, Kuckling HF, Zhalgasbaikyzy A, Ivanovská B, González García LE, Visalakshan RM, Vasilev K. It takes two for chronic wounds to heal: dispersing bacterial biofilm and modulating inflammation with dual action plasma coatings. RSC Adv 2020; 10:7368-7376. [PMID: 35492196 PMCID: PMC9049834 DOI: 10.1039/c9ra09875e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/06/2020] [Indexed: 11/21/2022] Open
Abstract
Chronic wounds are affecting increasingly larger portions of the general population and their treatment has essentially remained unchanged for the past century. This lack of progress is due to the complex problem that chronic wounds are simultaneously infected and inflamed. Both aspects need to be addressed together to achieve a better healing outcome. Hence, we hereby demonstrate that the stable nitroxide radical (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) can be plasma polymerized into smooth coatings (TEMPOpp), as seen via atomic force microscopy, X-ray photoelectron spectroscopy and ellipsometry. Upon contact with water, these coatings leach nitroxides into aqueous supernatant, as measured via EPR. We then exploited the known cell-signalling qualities of TEMPO to change the cellular behaviour of bacteria and human cells that come into contact with the surfaces. Specifically, the TEMPOpp coatings not only suppressed biofilm formation of the opportunistic bacterium Staphylococcus epidermidis but also dispersed already formed biofilm in a dose-dependent manner; a crucial aspect in treating chronic wounds that contain bacterial biofilm. Thus the coatings' microbiological efficacy correlated with their thickness and the thickest coating was the most efficient. Furthermore, this dose-dependent effect was mirrored in significant cytokine reduction of activated THP-1 macrophages for the four cytokines TNF-α, IL-1β, IL-6 and IP-10. At the same time, the THP-1 cells retained their ability to adhere and colonize the surfaces, as verified via SEM imaging. Thus, summarily, we have exploited the unique qualities of plasma polymerized TEMPO coatings in targeting both infection and inflammation simultaneously; demonstrating a novel alternative to how chronic wounds could be treated in the future. We plasma polymerized the stable nitroxide radical TEMPO into thin coatings and exploited the coatings' unique qualities in targeting both infection and inflammation simultaneously; demonstrating a novel alternative as to how chronic wounds could be treated in the future.![]()
Collapse
Affiliation(s)
| | | | | | | | - Barbora Ivanovská
- School of Engineering
- University of South Australia
- Mawson Lakes
- Australia
| | | | | | - Krasimir Vasilev
- School of Engineering
- University of South Australia
- Mawson Lakes
- Australia
| |
Collapse
|
38
|
Payne AT, Davidson AJ, Kan J, Peipoch M, Bier R, Williamson K. Widespread cryptic viral infections in lotic biofilms. Biofilm 2019; 2:100016. [PMID: 33447802 PMCID: PMC7798469 DOI: 10.1016/j.bioflm.2019.100016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 11/06/2019] [Accepted: 11/29/2019] [Indexed: 12/01/2022] Open
Abstract
Viruses have important impacts on aquatic microbial ecology and have been studied at length in the global ocean. However, the roles of bacteriophages in lotic ecosystems, particularly in benthic biofilms, have been largely under-studied. The main goals of this work were to determine whether viruses are consistent members of natural benthic biofilm communities of freshwater streams; whether temperate phages are present and active in such biofilms; and whether community profiling approaches like RAPD-PCR can be adapted to characterize biofilm virus communities. Results from both field and laboratory experiments suggest that viruses are consistent members of lotic biofilm communities. Interestingly, prophage induction was statistically significant but only a small percentage of the total bacterial population appeared to harbor prophage or engaged in induction. Finally, while the use of RAPD-PCR for the community level profiling of biofilm viral communities suggests temporal change in response to biofilm maturity, further refinements are required for broad-scale quantitative application.
Collapse
Affiliation(s)
| | | | - Jinjun Kan
- Stroud Water Research Center, 970 Spencer Rd, Avondale, PA, 19311, USA
| | - Marc Peipoch
- Stroud Water Research Center, 970 Spencer Rd, Avondale, PA, 19311, USA
| | - Raven Bier
- Stroud Water Research Center, 970 Spencer Rd, Avondale, PA, 19311, USA
| | | |
Collapse
|
39
|
Franke JD, Braverman AL, Cunningham AM, Eberhard EE, Perry GA. Erythrosin B: a versatile colorimetric and fluorescent vital dye for bacteria. Biotechniques 2019; 68:7-13. [PMID: 31718252 DOI: 10.2144/btn-2019-0066] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Rapidly assaying cell viability for diverse bacteria species is not always straightforward. In eukaryotes, cell viability is often determined using colorimetric dyes; however, such dyes have not been identified for bacteria. We screened different dyes and found that erythrosin B (EB), a visibly red dye with fluorescent properties, functions as a vital dye for many Gram-positive and -negative bacteria. EB worked at a similar concentration for all bacteria studied and incubations were as short as 5 min. Given EB's spectral properties, diverse experimental approaches are possible to rapidly visualize and/or quantitate dead bacterial cells in a population. As the first broadly applicable colorimetric viability dye for bacteria, EB provides a cost-effective alternative for researchers in academia and industry.
Collapse
Affiliation(s)
- Josef D Franke
- Department of Biology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Ann L Braverman
- Department of Biology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Alison M Cunningham
- Department of Biology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Erin E Eberhard
- Department of Biology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Greg A Perry
- Department of Medical Microbiology & Immunology, 2500 California Plaza, Omaha, NE 68178, USA
| |
Collapse
|
40
|
Schlomann BH, Wiles TJ, Wall ES, Guillemin K, Parthasarathy R. Sublethal antibiotics collapse gut bacterial populations by enhancing aggregation and expulsion. Proc Natl Acad Sci U S A 2019; 116:21392-21400. [PMID: 31591228 PMCID: PMC6815146 DOI: 10.1073/pnas.1907567116] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Antibiotics induce large and highly variable changes in the intestinal microbiome even at sublethal concentrations, through mechanisms that remain elusive. Using gnotobiotic zebrafish, which allow high-resolution examination of microbial dynamics, we found that sublethal doses of the common antibiotic ciprofloxacin cause severe drops in bacterial abundance. Contrary to conventional views of antimicrobial tolerance, disruption was more pronounced for slow-growing, aggregated bacteria than for fast-growing, planktonic species. Live imaging revealed that antibiotic treatment promoted bacterial aggregation and increased susceptibility to intestinal expulsion. Intestinal mechanics therefore amplify the effects of antibiotics on resident bacteria. Microbial dynamics are captured by a biophysical model that connects antibiotic-induced collapses to gelation phase transitions in soft materials, providing a framework for predicting the impact of antibiotics on the intestinal microbiome.
Collapse
Affiliation(s)
- Brandon H Schlomann
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
- Department of Physics, University of Oregon, Eugene, OR 97403
- Materials Science Institute, University of Oregon, Eugene, OR 97403
| | - Travis J Wiles
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Elena S Wall
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Karen Guillemin
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
- Humans and the Microbiome Program, CIFAR, Toronto, ON M5G 1Z8, Canada
| | - Raghuveer Parthasarathy
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403;
- Department of Physics, University of Oregon, Eugene, OR 97403
- Materials Science Institute, University of Oregon, Eugene, OR 97403
| |
Collapse
|
41
|
Methods Used for the Eradication of Staphylococcal Biofilms. Antibiotics (Basel) 2019; 8:antibiotics8040174. [PMID: 31590240 PMCID: PMC6963202 DOI: 10.3390/antibiotics8040174] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 09/27/2019] [Accepted: 10/01/2019] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus aureus is considered one of the leading pathogens responsible for community and healthcare-associated infections. Among them, infections caused by methicillin-resistant strains (MRSA) are connected with ineffective or prolonged treatment. The therapy of staphylococcal infections faces many difficulties, not only because of the bacteria's resistance to antibiotics and the multiplicity of virulence factors it produces, but also due to its ability to form a biofilm. The present review focuses on several approaches used for the assessment of staphylococcal biofilm eradication. The methods described here are successfully applied in research on the prevention of biofilm-associated infections, as well as in their management. They include not only the evaluation of the antimicrobial activity of novel compounds, but also the methods for biomaterial functionalization. Moreover, the advantages and limitations of different dyes and techniques used for biofilm characterization are discussed. Therefore, this review may be helpful for those scientists who work on the development of new antistaphylococcal compounds.
Collapse
|
42
|
Cattò C, Cappitelli F. Testing Anti-Biofilm Polymeric Surfaces: Where to Start? Int J Mol Sci 2019; 20:E3794. [PMID: 31382580 PMCID: PMC6696330 DOI: 10.3390/ijms20153794] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 08/02/2019] [Indexed: 12/11/2022] Open
Abstract
Present day awareness of biofilm colonization on polymeric surfaces has prompted the scientific community to develop an ever-increasing number of new materials with anti-biofilm features. However, compared to the large amount of work put into discovering potent biofilm inhibitors, only a small number of papers deal with their validation, a critical step in the translation of research into practical applications. This is due to the lack of standardized testing methods and/or of well-controlled in vivo studies that show biofilm prevention on polymeric surfaces; furthermore, there has been little correlation with the reduced incidence of material deterioration. Here an overview of the most common methods for studying biofilms and for testing the anti-biofilm properties of new surfaces is provided.
Collapse
Affiliation(s)
- Cristina Cattò
- Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy
| | - Francesca Cappitelli
- Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy.
| |
Collapse
|
43
|
Brezhnev A, Neelakantan P, Tanaka R, Brezhnev S, Fokas G, Matinlinna JP. Antibacterial Additives in Epoxy Resin-Based Root Canal Sealers: A Focused Review. Dent J (Basel) 2019; 7:E72. [PMID: 31266165 PMCID: PMC6784478 DOI: 10.3390/dj7030072] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/31/2019] [Accepted: 06/05/2019] [Indexed: 01/16/2023] Open
Abstract
Dental materials used in root canal treatment have undergone substantial improvements over the past decade. However, one area that still remains to be addressed is the ability of root canal fillings to effectively entomb, kill bacteria, and prevent the formation of a biofilm, all of which will prevent reinfection of the root canal system. Thus far, no published review has analysed the literature on antimicrobial additives to root canal sealers and their influence on physicochemical properties. The aim of this paper was to systematically review the current literature on antimicrobial additives in root canal sealers, their anti-fouling effects, and influence on physicochemical properties. A systematic search was performed in two databases (PubMed and Scopus) to identify studies that investigated the effect of antimicrobial additives in epoxy resin-based root canal sealers. The nature of additives, their antimicrobial effects, methods of antimicrobial testing are critically discussed. The effects on sealer properties have also been reviewed. A total of 31 research papers were reviewed in this work. A variety of antimicrobial agents have been evaluated as additives to epoxy resin-based sealers, including quaternary ammonium compounds, chlorhexidine, calcium hydroxide, iodoform, natural extracts, antibiotics, antifungal drugs, and antimicrobial agent-functionalised nanoparticles. Antimicrobial additives generally improved the antimicrobial effect of epoxy resin-based sealers mainly without deteriorating the physicochemical properties, which mostly remained in accordance with ISO and ANSI/ADA specifications.
Collapse
Affiliation(s)
- Alexander Brezhnev
- Applied Oral Sciences-Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Prasanna Neelakantan
- Discipline of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
| | - Ray Tanaka
- Applied Oral Sciences-Oral and Maxillofacial Radiology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Sergey Brezhnev
- Discipline of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - George Fokas
- Department of Prosthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Jukka P Matinlinna
- Applied Oral Sciences-Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| |
Collapse
|
44
|
Kreth J, Ferracane J, Pfeifer C, Khajotia S, Merritt J. At the Interface of Materials and Microbiology: A Call for the Development of Standardized Approaches to Assay Biomaterial-Biofilm Interactions. J Dent Res 2019; 98:850-852. [PMID: 31173560 PMCID: PMC6616120 DOI: 10.1177/0022034519854685] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- J. Kreth
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, USA
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA
| | - J.L. Ferracane
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, USA
| | - C.S. Pfeifer
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, USA
| | - S. Khajotia
- Department of Restorative Sciences, College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - J. Merritt
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, USA
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA
| |
Collapse
|
45
|
Adeyemo FE, Singh G, Reddy P, Bux F, Stenström TA. Efficiency of chlorine and UV in the inactivation of Cryptosporidium and Giardia in wastewater. PLoS One 2019; 14:e0216040. [PMID: 31083664 PMCID: PMC6513095 DOI: 10.1371/journal.pone.0216040] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 04/13/2019] [Indexed: 01/05/2023] Open
Abstract
Wastewater from different sources is contaminated by protozoan parasites including Cryptosporidium and Giardia. Many protozoan parasites are becoming resistant to chemical treatment. The challenge of finding alternatives is presented to researchers by exploring other methods of eliminating protozoan parasites from wastewater. The aim of this study was to assess the speciation and the viability of Cryptosporidium and Giardia in environmental samples with the specific objective of evaluating if effluent chlorination and UV affect the viability. Different doses of chlorine with different exposure times were experimented with both distilled water and waste water spiked with (oo)cysts derived from environmental samples. UV irradiation at different doses was also experimented using the same spiked samples. Two methods of quantification and detection, namely, microscopy and flow cytometry, were used in the experiment. Two vital dyes, Syto-9+PI and DAPI+PI, were the used for staining the collected wastewater samples. It was found that the (oo)cysts responded to chlorination and UV treatments with Giardia responding better than Cryptosporidium. Giardia responded very well to UV irradiations with almost 0 percent remaining viable after a low dose of UV. Cryptosporidium was found to be resistant to chlorination even at high doses but responded well to high UV doses. DAPI+PI dye gave a lower mean percentage viability values than Syto-9+PI. Flow cytometry gave higher mean percentage than microscopy from the results. It is concluded that UV is a promising alternative to Chlorine in removing Cryptosporidium and Giardia from waste water. Appropriate treatment method for wastewater is necessary to minimize water resources pollution when wastewater is released into water systems.
Collapse
Affiliation(s)
- Folasade Esther Adeyemo
- SARChI Chair, Institute for Water and Wastewater Technology (IWWT), Durban University of Technology, Durban, South Africa
- Department of Community Health Studies, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
- * E-mail: ,
| | - Gulshan Singh
- SARChI Chair, Institute for Water and Wastewater Technology (IWWT), Durban University of Technology, Durban, South Africa
| | - Poovendhree Reddy
- Department of Community Health Studies, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
| | - Faizal Bux
- SARChI Chair, Institute for Water and Wastewater Technology (IWWT), Durban University of Technology, Durban, South Africa
| | - Thor Axel Stenström
- SARChI Chair, Institute for Water and Wastewater Technology (IWWT), Durban University of Technology, Durban, South Africa
| |
Collapse
|
46
|
Bogachev MI, Volkov VY, Kolaev G, Chernova L, Vishnyakov I, Kayumov A. Selection and Quantification of Objects in Microscopic Images: from Multi-Criteria to Multi-Threshold Analysis. BIONANOSCIENCE 2018. [DOI: 10.1007/s12668-018-0588-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
47
|
Tejada S, Baca P, Ferrer-Luque CM, Ruiz-Linares M, Valderrama MJ, Arias-Moliz MT. Influence of dentine debris and organic tissue on the properties of sodium hypochlorite solutions. Int Endod J 2018; 52:114-122. [DOI: 10.1111/iej.12986] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 07/13/2018] [Indexed: 11/29/2022]
Affiliation(s)
- S. Tejada
- Department of Microbiology; University of Granada; Granada Spain
| | - P. Baca
- Department of Stomatology; School of Dentistry; University of Granada; Granada Spain
| | - C. M. Ferrer-Luque
- Department of Stomatology; School of Dentistry; University of Granada; Granada Spain
| | - M. Ruiz-Linares
- Department of Stomatology; School of Dentistry; University of Granada; Granada Spain
| | - M. J. Valderrama
- Department of Statistics and Operations Research; School of Pharmacy; University of Granada; Granada Spain
| | | |
Collapse
|
48
|
Bogachev MI, Volkov VY, Markelov OA, Trizna EY, Baydamshina DR, Melnikov V, Murtazina RR, Zelenikhin PV, Sharafutdinov IS, Kayumov AR. Fast and simple tool for the quantification of biofilm-embedded cells sub-populations from fluorescent microscopic images. PLoS One 2018; 13:e0193267. [PMID: 29715298 PMCID: PMC5929543 DOI: 10.1371/journal.pone.0193267] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 02/07/2018] [Indexed: 01/30/2023] Open
Abstract
Fluorescent staining is a common tool for both quantitative and qualitative assessment of pro- and eukaryotic cells sub-population fractions by using microscopy and flow cytometry. However, direct cell counting by flow cytometry is often limited, for example when working with cells rigidly adhered either to each other or to external surfaces like bacterial biofilms or adherent cell lines and tissue samples. An alternative approach is provided by using fluorescent microscopy and confocal laser scanning microscopy (CLSM), which enables the evaluation of fractions of cells subpopulations in a given sample. For the quantitative assessment of cell fractions in microphotographs, we suggest a simple two-step algorithm that combines single cells selection and the statistical analysis. To facilitate the first step, we suggest a simple procedure that supports finding the balance between the detection threshold and the typical size of single cells based on objective cell size distribution analysis. Based on a series of experimental measurements performed on bacterial and eukaryotic cells under various conditions, we show explicitly that the suggested approach effectively accounts for the fractions of different cell sub-populations (like the live/dead staining in our samples) in all studied cases that are in good agreement with manual cell counting on microphotographs and flow cytometry data. This algorithm is implemented as a simple software tool that includes an intuitive and user-friendly graphical interface for the initial adjustment of algorithm parameters to the microphotographs analysis as well as for the sequential analysis of homogeneous series of similar microscopic images without further user intervention. The software tool entitled BioFilmAnalyzer is freely available online at https://bitbucket.org/rogex/biofilmanalyzer/downloads/.
Collapse
Affiliation(s)
- Mikhail I. Bogachev
- Radio Systems Department & Biomedical Engineering Research Center, St. Petersburg Electrotechnical University, St. Petersburg, Russia
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Vladimir Yu Volkov
- Radio Systems Department & Biomedical Engineering Research Center, St. Petersburg Electrotechnical University, St. Petersburg, Russia
- Department of Radio Systems and Signal Processing, Bonch-Bruevich State Telecommunication University, St. Petersburg, Russia
- Department of Radio Engineering Systems, State University of Aerospace Instrumentation, St. Petersburg, Russia
| | - Oleg A. Markelov
- Radio Systems Department & Biomedical Engineering Research Center, St. Petersburg Electrotechnical University, St. Petersburg, Russia
| | - Elena Yu Trizna
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Diana R. Baydamshina
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Vladislav Melnikov
- Radio Systems Department & Biomedical Engineering Research Center, St. Petersburg Electrotechnical University, St. Petersburg, Russia
| | - Regina R. Murtazina
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Pavel V. Zelenikhin
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | | | - Airat R. Kayumov
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
- * E-mail:
| |
Collapse
|
49
|
Schöck M, Liebminger S, Berg G, Cernava T. First evaluation of alkylpyrazine application as a novel method to decrease microbial contaminations in processed meat products. AMB Express 2018; 8:54. [PMID: 29616370 PMCID: PMC5882472 DOI: 10.1186/s13568-018-0583-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 03/27/2018] [Indexed: 11/30/2022] Open
Abstract
Every year about 20% of the globally produced meat gets lost due to microbial spoilage. Nevertheless, the demand for processed meat is constantly rising and producers are searching for novel strategies to reduce microbial contaminations in their products. In the present study, we evaluated the applicability of alkylpyrazines as antimicrobial agents. These fragrant molecules naturally occur in different vegetables, fruits, roasted nut and meat. Several pyrazine derivatives are readily added to processed products for flavoring purposes in the food industry. To evaluate their potential for application, two derivatives were tested for their antimicrobial activity against meat-associated bacterial contaminants and chicken meat as a whole. Isolates assigned to Carnobacteriaceae, Enterobacteriaceae, Listeriaceae, and Moraxellaceae were substantially inhibited in the pilot tests. Moreover, treatments of pyrazine-susceptible isolates resulted in 4-log reductions in bacterial cell counts. The effect was more pronounced when the model contaminants were exposed to higher concentrations of 5-isobutyl-2,3-dimethylpyrazine. In a first small-scale application with processed chicken meat, it was demonstrated that the antimicrobial effects of 2-isobutyl-3-methylpyrazine can be improved by additionally lowering the water activity on the meat surface when maltodextrin is used as a carrier substance. At low pyrazine dosages, the number of viable bacteria was decreased up to 95% in comparison to the corresponding controls. A complementary imaging method that was developed to assess the efficacy on the product, reinforced the applicability of this two-component system.
Collapse
|
50
|
Sjollema J, Zaat SAJ, Fontaine V, Ramstedt M, Luginbuehl R, Thevissen K, Li J, van der Mei HC, Busscher HJ. In vitro methods for the evaluation of antimicrobial surface designs. Acta Biomater 2018; 70:12-24. [PMID: 29432983 DOI: 10.1016/j.actbio.2018.02.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 01/12/2018] [Accepted: 02/01/2018] [Indexed: 11/16/2022]
Abstract
Bacterial adhesion and subsequent biofilm formation on biomedical implants and devices are a major cause of their failure. As systemic antibiotic treatment is often ineffective, there is an urgent need for antimicrobial biomaterials and coatings. The term "antimicrobial" can encompass different mechanisms of action (here termed "antimicrobial surface designs"), such as antimicrobial-releasing, contact-killing or non-adhesivity. Biomaterials equipped with antimicrobial surface designs based on different mechanisms of action require different in vitro evaluation methods. Available industrial standard evaluation tests do not address the specific mechanisms of different antimicrobial surface designs and have therefore been modified over the past years, adding to the myriad of methods available in the literature to evaluate antimicrobial surface designs. The aim of this review is to categorize fourteen presently available methods including industrial standard tests for the in vitro evaluation of antimicrobial surface designs according to their suitability with respect to their antimicrobial mechanism of action. There is no single method or industrial test that allows to distinguish antimicrobial designs according to all three mechanisms identified here. However, critical consideration of each method clearly relates the different methods to a specific mechanism of antimicrobial action. It is anticipated that use of the provided table with the fourteen methods will avoid the use of wrong methods for evaluating new antimicrobial designs and therewith facilitate translation of novel antimicrobial biomaterials and coatings to clinical use. The need for more and better updated industrial standard tests is emphasized. STATEMENT OF SIGNIFICANCE European COST-action TD1305, IPROMEDAI aims to provide better understanding of mechanisms of antimicrobial surface designs of biomaterial implants and devices. Current industrial evaluation standard tests do not sufficiently account for different, advanced antimicrobial surface designs, yet are urgently needed to obtain convincing in vitro data for approval of animal experiments and clinical trials. This review aims to provide an innovative and clear guide to choose appropriate evaluation methods for three distinctly different mechanisms of antimicrobial design: (1) antimicrobial-releasing, (2) contact-killing and (3) non-adhesivity. Use of antimicrobial evaluation methods and definition of industrial standard tests, tailored toward the antimicrobial mechanism of the design, as identified here, fulfill a missing link in the translation of novel antimicrobial surface designs to clinical use.
Collapse
Affiliation(s)
- Jelmer Sjollema
- University of Groningen, University Medical Center Groningen, Department of BioMedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
| | - Sebastian A J Zaat
- Department of Medical Microbiology, CINIMA (Center for Infection and Immunity Amsterdam), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Veronique Fontaine
- Unit of Pharmaceutical Microbiology and Hygiene, Faculty of Pharmacy, Université Libre de Bruxelles (ULB), Campus Plaine, Boulevard du Triomphe, 1050 Brussels, Belgium
| | | | - Reto Luginbuehl
- RMS Foundation, Bischmattstrasse 12, 2544 Bettlach, Switzerland
| | - Karin Thevissen
- Centre for Microbial and Plant Genetics, CMPG, University of Leuven, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
| | - Jiuyi Li
- School of Civil Engineering, Beijing Jiaotong University, 3 Shangyuancun, Xizhimenwai, Beijing 100044, China
| | - Henny C van der Mei
- University of Groningen, University Medical Center Groningen, Department of BioMedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Henk J Busscher
- University of Groningen, University Medical Center Groningen, Department of BioMedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| |
Collapse
|