1
|
Aherne O, Mørch M, Ortiz R, Shannon O, Davies JR. A novel multiplex fluorescent-labeling method for the visualization of mixed-species biofilms in vitro. Microbiol Spectr 2024:e0025324. [PMID: 38785429 DOI: 10.1128/spectrum.00253-24] [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: 01/30/2024] [Accepted: 04/17/2024] [Indexed: 05/25/2024] Open
Abstract
In nature, bacteria usually exist as mixed-species biofilms, where they engage in a range of synergistic and antagonistic interactions that increase their resistance to environmental challenges. Biofilms are a major cause of persistent infections, and dispersal from initial foci can cause new infections at distal sites thus warranting further investigation. Studies of development and spatial interactions in mixed-species biofilms can be challenging due to difficulties in identifying the different bacterial species in situ. Here, we apply CellTrace dyes to studies of biofilm bacteria and present a novel application for multiplex labeling, allowing identification of different bacteria in mixed-species, in vitro biofilm models. Oral bacteria labeled with CellTrace dyes (far red, yellow, violet, and CFSE [green]) were used to create single- and mixed-species biofilms, which were analyzed with confocal spinning disk microscopy (CSDM). Biofilm supernatants were studied with flow cytometry (FC). Both Gram-positive and Gram-negative bacteria were well labeled and CSDM revealed biofilms with clear morphology and stable staining for up to 4 days. Analysis of CellTrace labeled cells in supernatants using FC showed differences in the biofilm dispersal between bacterial species. Multiplexing with different colored dyes allowed visualization of spatial relationships between bacteria in mixed-species biofilms and relative coverage by the different species was revealed through segmentation of the CSDM images. This novel application, thus, offers a powerful tool for studying structure and composition of mixed-species biofilms in vitro.IMPORTANCEAlthough most chronic infections are caused by mixed-species biofilms, much of our knowledge still comes from planktonic cultures of single bacterial species. Studies of formation and development of mixed-species biofilms are, therefore, required. This work describes a method applicable to labeling of bacteria for in vitro studies of biofilm structure and dispersal. Critically, labeled bacteria can be multiplexed for identification of different species in mixed-species biofilms using confocal spinning disk microscopy, facilitating investigation of biofilm development and spatial interactions under different environmental conditions. The study is an important step in increasing the tools available for such complex and challenging studies.
Collapse
Affiliation(s)
- Olivia Aherne
- Section for Oral Biology and Pathology, Faculty of Odontology and Biofilms Research Center for Biointerfaces, Malmö University, Malmö, Sweden
- CR Competence, Lund, Sweden
| | - Martina Mørch
- Section for Oral Biology and Pathology, Faculty of Odontology and Biofilms Research Center for Biointerfaces, Malmö University, Malmö, Sweden
| | | | - Oonagh Shannon
- Section for Oral Biology and Pathology, Faculty of Odontology and Biofilms Research Center for Biointerfaces, Malmö University, Malmö, Sweden
| | - Julia R Davies
- Section for Oral Biology and Pathology, Faculty of Odontology and Biofilms Research Center for Biointerfaces, Malmö University, Malmö, Sweden
| |
Collapse
|
2
|
Yeo JH, Begam N, Leow WT, Goh JX, Zhong Y, Cai Y, Kwa ALH. Ironing out Persisters? Revisiting the Iron Chelation Strategy to Target Planktonic Bacterial Persisters Harboured in Carbapenem-Resistant Escherichia coli. Microorganisms 2024; 12:972. [PMID: 38792801 PMCID: PMC11123761 DOI: 10.3390/microorganisms12050972] [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: 03/15/2024] [Revised: 05/02/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
Antibiotic resistance is a global health crisis. Notably, carbapenem-resistant Enterobacterales (CRE) pose a significant clinical challenge due to the limited effective treatment options. This problem is exacerbated by persisters that develop upon antibiotic exposure. Bacteria persisters can tolerate high antibiotic doses and can cause recalcitrant infections, potentially developing further antibiotic resistance. Iron is a critical micronutrient for survival. We aimed to evaluate the utility of iron chelators, alone and in combination with antibiotics, in managing persisters. We hypothesized that iron chelators eradicate CRE persisters in vitro, when administered in combination with antibiotics. Our screening revealed three clinical isolates with bacteria persisters that resuscitated upon antibiotic removal. These isolates were treated with both meropenem and an iron chelator (deferoxamine mesylate, deferiprone or dexrazoxane) over 24 h. Against our hypothesis, bacteria persisters survived and resuscitated upon withdrawing both the antibiotic and iron chelator. Pursuing our aim, we next hypothesized that iron chelation is feasible as a post-antibiotic treatment in managing and suppressing persisters' resuscitation. We exposed bacteria persisters to an iron chelator without antibiotics. Flow cytometric assessments revealed that iron chelators are inconsistent in suppressing persister resuscitation. Collectively, these results suggest that the iron chelation strategy may not be useful as an antibiotic adjunct to target planktonic bacteria persisters.
Collapse
Affiliation(s)
- Jia Hao Yeo
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
- SingHealth-Duke-NUS Academic Clinical Programme (Pathology), Singapore 169857, Singapore
| | - Nasren Begam
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
| | - Wan Ting Leow
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
| | - Jia Xuan Goh
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
| | - Yang Zhong
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
- Department of Clinical Translational Research, Singapore General Hospital, Singapore 169856, Singapore
| | - Yiying Cai
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
| | - Andrea Lay-Hoon Kwa
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
- SingHealth-Duke-NUS Academic Clinical Programme (Medicine), Singapore 169857, Singapore
- Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
| |
Collapse
|
3
|
He W, Liu H, Wang Z, Tay FR, Shen Y. The dynamics of bacterial proliferation, viability, and extracellular polymeric substances in oral biofilm development. J Dent 2024; 143:104882. [PMID: 38331378 DOI: 10.1016/j.jdent.2024.104882] [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: 01/26/2024] [Revised: 02/04/2024] [Accepted: 02/05/2024] [Indexed: 02/10/2024] Open
Abstract
OBJECTIVES This study investigated the relationship between bacterial growth, viability, and extracellular polymeric substances (EPS) formation in biofilms, particularly regarding resistance development. It also examined the impact of chemical factors on the EPS matrix and bacterial proliferation in oral biofilms. METHODS Three multi-species oral biofilms were incubated in anaerobic conditions. Three strains of Enterococcus faecalis were incubated in aerobic conditions. The incubation periods ranged from 0 h to 7 days for short-term biofilms, and from 3 to 90 days for long-term biofilms. Fluorescent labeling with carboxyfluorescein diacetate succinimidyl ester (CFSE) and flow cytometry were used to track EPS and bacterial growth. Confocal laser scanning microscopy (CLSM) assessed bacterial viability and EPS structure. Biofilms aged 7, 14, and 21 days were treated with 2 % chlorhexidine (CHX) and 1 % sodium hypochlorite (NaOCl) to evaluate their effects on EPS and bacterial proliferation. RESULTS Short-term biofilms showed rapid bacterial proliferation and a gradual increase in EPS, maintaining stable viability. In the first two weeks, a significant rise in CFSE indicated growing maturity. From 14 to 90 days, EPS and CFSE levels stabilized. Following treatment, CHX significantly reduced bacterial proliferation, while NaOCl decreased EPS volume. CONCLUSIONS Biofilm development involves a balance between bacterial proliferation and EPS production. The complexity of this process poses challenges in treating biofilm-associated infections, requiring strategies tailored to the biofilm's developmental stage. CLINICAL SIGNIFICANCE For effective root canal treatment, it is imperative to focus on reducing bacterial proliferation during the early stages of oral infections. In contrast, strategies aimed at minimizing EPS production could be more beneficial for long-term management of these conditions.
Collapse
Affiliation(s)
- Wendan He
- Department of Stomatology, The Affiliated Hospital of Wuhan Traditional Chinese and Western Medicine, Tongji Medical College of HUST, Wuhan 430022, China
| | - He Liu
- Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, 2199 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Zhejun Wang
- Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, 2199 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Franklin R Tay
- Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA.
| | - Ya Shen
- Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, 2199 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada.
| |
Collapse
|
4
|
Marro FC, Laurent F, Josse J, Blocker AJ. Methods to monitor bacterial growth and replicative rates at the single-cell level. FEMS Microbiol Rev 2022; 46:6623663. [PMID: 35772001 PMCID: PMC9629498 DOI: 10.1093/femsre/fuac030] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 06/01/2022] [Accepted: 06/28/2022] [Indexed: 01/09/2023] Open
Abstract
The heterogeneity of bacterial growth and replicative rates within a population was proposed a century ago notably to explain the presence of bacterial persisters. The term "growth rate" at the single-cell level corresponds to the increase in size or mass of an individual bacterium while the "replicative rate" refers to its division capacity within a defined temporality. After a decades long hiatus, recent technical innovative approaches allow population growth and replicative rates heterogeneity monitoring at the single-cell level resuming in earnest. Among these techniques, the oldest and widely used is time-lapse microscopy, most recently combined with microfluidics. We also discuss recent fluorescence dilution methods informing only on replicative rates and best suited. Some new elegant single cell methods so far only sporadically used such as buoyant mass measurement and stable isotope probing have emerged. Overall, such tools are widely used to investigate and compare the growth and replicative rates of bacteria displaying drug-persistent behaviors to that of bacteria growing in specific ecological niches or collected from patients. In this review, we describe the current methods available, discussing both the type of queries these have been used to answer and the specific strengths and limitations of each method.
Collapse
Affiliation(s)
- Florian C Marro
- Evotec ID Lyon, In Vitro Biology, Infectious Diseases and Antibacterials Unit, Gerland, 69007 Lyon, France,CIRI – Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, F-69007 Lyon, France
| | - Frédéric Laurent
- CIRI – Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, F-69007 Lyon, France,Institut des Sciences Pharmaceutiques et Biologiques (ISPB), Université Claude Bernard Lyon 1, Lyon, France,Centre de Référence pour la prise en charge des Infections ostéo-articulaires complexes (CRIOAc Lyon; www.crioac-lyon.fr), Hospices Civils de Lyon, Lyon, France,Laboratoire de bactériologie, Institut des Agents Infectieux, French National Reference Center for Staphylococci, Hospices Civils de Lyon, Lyon, France
| | - Jérôme Josse
- CIRI – Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, F-69007 Lyon, France,Institut des Sciences Pharmaceutiques et Biologiques (ISPB), Université Claude Bernard Lyon 1, Lyon, France,Centre de Référence pour la prise en charge des Infections ostéo-articulaires complexes (CRIOAc Lyon; www.crioac-lyon.fr), Hospices Civils de Lyon, Lyon, France
| | - Ariel J Blocker
- Corresponding author. Evotec ID Lyon, In Vitro Biology, Infectious Diseases and Antibacterials Unit, France. E-mail:
| |
Collapse
|
5
|
Lynam EG, Lane JAE, Finding EJT, Wheeler-Jones CPD. Simultaneous Measurement of Endothelial Cell Proliferation and Cell Cycle Stage Using Flow Cytometry. Methods Mol Biol 2022; 2475:223-228. [PMID: 35451761 DOI: 10.1007/978-1-0716-2217-9_16] [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] [Indexed: 06/14/2023]
Abstract
Endothelial cell proliferation rate is an important indicator of vascular health. Being able to detect the rate of endothelial cell proliferation, or cell cycle disturbances after intervention is a valuable tool for analysing any beneficial or detrimental effects of treatments in vitro. Here, we describe a straightforward flow cytometric-based method of proliferation and cell cycle tracking that can be performed on human endothelial cells in culture over several days.
Collapse
Affiliation(s)
- Eleanor G Lynam
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - James A E Lane
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | | | | |
Collapse
|
6
|
Bernard-Raichon L, Colom A, Monard SC, Namouchi A, Cescato M, Garnier H, Leon-Icaza SA, Métais A, Dumas A, Corral D, Ghebrendrias N, Guilloton P, Vérollet C, Hudrisier D, Remot A, Langella P, Thomas M, Cougoule C, Neyrolles O, Lugo-Villarino G. A Pulmonary Lactobacillus murinus Strain Induces Th17 and RORγt + Regulatory T Cells and Reduces Lung Inflammation in Tuberculosis. THE JOURNAL OF IMMUNOLOGY 2021; 207:1857-1870. [PMID: 34479945 DOI: 10.4049/jimmunol.2001044] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 07/24/2021] [Indexed: 12/31/2022]
Abstract
The lungs harbor multiple resident microbial communities, otherwise known as the microbiota. There is an emerging interest in deciphering whether the pulmonary microbiota modulate local immunity, and whether this knowledge could shed light on mechanisms operating in the response to respiratory pathogens. In this study, we investigate the capacity of a pulmonary Lactobacillus strain to modulate the lung T cell compartment and assess its prophylactic potential upon infection with Mycobacterium tuberculosis, the etiological agent of tuberculosis. In naive mice, we report that a Lactobacillus murinus (Lagilactobacillus murinus) strain (CNCM I-5314) increases the presence of lung Th17 cells and of a regulatory T cell (Treg) subset known as RORγt+ Tregs. In particular, intranasal but not intragastric administration of CNCM I-5314 increases the expansion of these lung leukocytes, suggesting a local rather than systemic effect. Resident Th17 and RORγt+ Tregs display an immunosuppressive phenotype that is accentuated by CNCM I-5314. Despite the well-known ability of M. tuberculosis to modulate lung immunity, the immunomodulatory effect by CNCM I-5314 is dominant, as Th17 and RORγt+ Tregs are still highly increased in the lung at 42-d postinfection. Importantly, CNCM I-5314 administration in M. tuberculosis-infected mice results in reduction of pulmonary inflammation, without increasing M. tuberculosis burden. Collectively, our findings provide evidence for an immunomodulatory capacity of CNCM I-5314 at steady state and in a model of chronic inflammation in which it can display a protective role, suggesting that L. murinus strains found in the lung may shape local T cells in mice and, perhaps, in humans.
Collapse
Affiliation(s)
- Lucie Bernard-Raichon
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France;
| | - André Colom
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Sarah C Monard
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Amine Namouchi
- Centre for Integrative Genetics, Norwegian University of Life Sciences, As, Norway; and
| | - Margaux Cescato
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Hugo Garnier
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Stephen A Leon-Icaza
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Arnaud Métais
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Alexia Dumas
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Dan Corral
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Natsinet Ghebrendrias
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Pauline Guilloton
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Christel Vérollet
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Denis Hudrisier
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Aude Remot
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Philippe Langella
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Muriel Thomas
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Céline Cougoule
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Olivier Neyrolles
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Geanncarlo Lugo-Villarino
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France;
| |
Collapse
|
7
|
Gutiérrez R, Ram Y, Berman J, Carstens Marques de Sousa K, Nachum-Biala Y, Britzi M, Elad D, Glaser G, Covo S, Harrus S. Adaptive resistance mutations at supra-inhibitory concentrations independent of SOS mutagenesis. Mol Biol Evol 2021; 38:4095-4115. [PMID: 34175952 PMCID: PMC8476149 DOI: 10.1093/molbev/msab196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Emergence of resistant bacteria during antimicrobial treatment is one of the most critical and universal health threats. It is known that several stress-induced mutagenesis and heteroresistance mechanisms can enhance microbial adaptation to antibiotics. Here, we demonstrate that the pathogen Bartonella can undergo stress-induced mutagenesis despite the fact it lacks error-prone polymerases, the rpoS gene and functional UV-induced mutagenesis. We demonstrate that Bartonella acquire de novo single mutations during rifampicin exposure at suprainhibitory concentrations at a much higher rate than expected from spontaneous fluctuations. This is while exhibiting a minimal heteroresistance capacity. The emerged resistant mutants acquired a single rpoB mutation, whereas no other mutations were found in their whole genome. Interestingly, the emergence of resistance in Bartonella occurred only during gradual exposure to the antibiotic, indicating that Bartonella sense and react to the changing environment. Using a mathematical model, we demonstrated that, to reproduce the experimental results, mutation rates should be transiently increased over 1,000-folds, and a larger population size or greater heteroresistance capacity is required. RNA expression analysis suggests that the increased mutation rate is due to downregulation of key DNA repair genes (mutS, mutY, and recA), associated with DNA breaks caused by massive prophage inductions. These results provide new evidence of the hazard of antibiotic overuse in medicine and agriculture.
Collapse
Affiliation(s)
- Ricardo Gutiérrez
- The Koret School of Veterinary Medicine, Faculty of Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel.,The Center for Research in Tropical Diseases, Faculty of Microbiology, University of Costa Rica, San José, Costa Rica
| | - Yoav Ram
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel.,School of Computer Science, Interdisciplinary Center Herzliya, Herzliya, Israel
| | - Judith Berman
- Shmunis School of Biomedicine and Cancer, Faculty of Life Sciences, Tel Aviv University, Tel Aviv University, Ramat Aviv, Israel
| | | | - Yaarit Nachum-Biala
- The Koret School of Veterinary Medicine, Faculty of Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Malka Britzi
- The National Residue Control Laboratory, The Kimron Veterinary Institute, Bet Dagan, Israel
| | - Daniel Elad
- Department of Clinical Bacteriology and Mycology, The Kimron Veterinary Institute, Bet Dagan, Israel
| | - Gad Glaser
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shay Covo
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Shimon Harrus
- The Koret School of Veterinary Medicine, Faculty of Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| |
Collapse
|
8
|
Synergistic effects of shear stress, moderate electric field, and nisin for the inactivation of Escherichia coli K12 and Listeria innocua in clear apple juice. Food Control 2020. [DOI: 10.1016/j.foodcont.2020.107209] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
9
|
Determining the Development of Persisters in Extensively Drug-Resistant Acinetobacter baumannii upon Exposure to Polymyxin B-Based Antibiotic Combinations Using Flow Cytometry. Antimicrob Agents Chemother 2020; 64:AAC.01712-19. [PMID: 31818819 DOI: 10.1128/aac.01712-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/22/2019] [Indexed: 12/24/2022] Open
Abstract
Polymyxin B-based combinations are increasingly prescribed as a last-line option against extensively drug-resistant (XDR) Acinetobacter baumannii It is unknown if such combinations can result in the development of nondividing persister cells in XDR A. baumannii We investigated persister development upon exposure of XDR A. baumannii to polymyxin B-based antibiotic combinations using flow cytometry. Time-kill studies (TKSs) were conducted in three nonclonal XDR A. baumannii strains with 5 log10 CFU/ml bacteria against polymyxin B alone and polymyxin B-based two-drug combinations over 24 h. At different time points, samples were obtained and enumerated by viable plating and flow cytometry. Propidium iodide and carboxyfluorescein succinimidyl ester dyes were used to differentiate between live and dead cells and between dividing and nondividing cells, respectively, at the single-cell level, and nondividing live cells were resuscitated and characterized phenotypically. Our results from viable plating showed that polymyxin B plus meropenem and polymyxin B plus rifampin were each bactericidal (>99.9% kill compared to the initial inoculum) against 2/3 XDR A. baumannii strains at 24 h. By flow cytometry, however, none of the combinations were bactericidal against XDR A. baumannii at 24 h. Further analysis using cellular dyes in flow cytometry revealed that upon exposure to polymyxin B-based combinations, XDR A. baumannii entered a viable but nondividing persister state. These bacterial cells reinitiated division upon the removal of antibiotic pressure and did not have a growth deficit compared to the parent strain. We conclude that persister cells develop in XDR A. baumannii upon exposure to polymyxin B-based combinations and that nonplating methods appear to complement viable-plating methods in describing the killing activity of polymyxin B-based combinations against XDR A. baumannii.
Collapse
|
10
|
Chen S, Gong P, Zhang J, Shan Y, Han X, Zhang L. Quantitative analysis of Lactobacillus delbrueckii subsp. bulgaricus cell division and death using fluorescent dye tracking. J Microbiol Methods 2020; 169:105832. [DOI: 10.1016/j.mimet.2020.105832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 12/29/2019] [Accepted: 01/01/2020] [Indexed: 12/30/2022]
|
11
|
Cal-Sabater P, Caro I, Castro MJ, Cao MJ, Mateo J, Quinto EJ. Flow Cytometry to Assess the Counts and Physiological State of Cronobacter sakazakii Cells after Heat Exposure. Foods 2019; 8:foods8120688. [PMID: 31888256 PMCID: PMC6963341 DOI: 10.3390/foods8120688] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/06/2019] [Accepted: 12/11/2019] [Indexed: 11/26/2022] Open
Abstract
Cronobacter sakazakii is an opportunistic pathogen that is associated with outbreaks of neonatal necrotizing enterocolitis, septicaemia, and meningitis. Reconstituted powdered infant formulae is the most common vehicle of infection. The aim of the present study is to gain insight into the physiological states of C. sakazakii cells using flow cytometry to detect the compromised cells, which are viable but non-culturable using plate-based methods, and to evaluate the impact of milk heat treatments on those populations. Dead-cell suspensions as well as heat-treated and non-heat-treated cell suspensions were used. After 60 or 65 °C treatments, the number of compromised cells increased as a result of cells with compromised membranes shifting from the heat-treated suspension. These temperatures were not effective at killing all bacteria but were effective at compromising their membranes. Thus, mild heat treatments are not enough to guarantee the safety of powered infant formulae. Flow cytometry was capable of detecting C. sakazakii’s compromised cells that cannot be detected with classical plate count methods; thus, it could be used as a screening test to decrease the risk derived from the presence of pathogenic viable but non-culturable cells in this food that is intended for newborns’ nutrition.
Collapse
Affiliation(s)
- Paloma Cal-Sabater
- Department of Nutrition and Food Science, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain; (P.C.-S.); (I.C.)
- Department of Nursery, Faculty of Nursery, University of Valladolid, 47005 Valladolid, Spain; (M.J.C.); (M.J.C.)
| | - Irma Caro
- Department of Nutrition and Food Science, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain; (P.C.-S.); (I.C.)
| | - María J. Castro
- Department of Nursery, Faculty of Nursery, University of Valladolid, 47005 Valladolid, Spain; (M.J.C.); (M.J.C.)
| | - María J. Cao
- Department of Nursery, Faculty of Nursery, University of Valladolid, 47005 Valladolid, Spain; (M.J.C.); (M.J.C.)
| | - Javier Mateo
- Department of Hygiene and Food Technology, Faculty of Veterinary Medicine, University of León, 24071 León, Spain;
| | - Emiliano J. Quinto
- Department of Nutrition and Food Science, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain; (P.C.-S.); (I.C.)
- Correspondence:
| |
Collapse
|
12
|
Buckley KM, Schuh NW, Heyland A, Rast JP. Analysis of immune response in the sea urchin larva. Methods Cell Biol 2018; 150:333-355. [PMID: 30777183 DOI: 10.1016/bs.mcb.2018.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Sea urchin larvae deploy a complex immune system in the context of relatively simple morphology. Several types of phagocytic or granular immune cells respond rapidly to microbes and microbial components within the body cavity. Many of these cells also respond to microbial disturbances in the gut lumen. In the course of immune response, hundreds of genes are up- and downregulated, many of which have homologs involved in immunity in other species. Thus, the larval sea urchin provides an experimentally advantageous model for investigating the response to immune challenge at the level of cell behavior and gene regulatory networks. Importantly, the morphological simplicity and optical clarity of these larvae allow studies to be carried out within the intact animal. Here, we outline techniques to probe and visualize the immune system of the feeding sea urchin larva, particularly for quantifying gene expression and cell migration as the animal responds to both pathogens and symbionts. Techniques addressed in this chapter include (1) exposure of larvae to microbes and microbial products in sea water and by blastocoelar microinjection, (2) time-lapse imaging of immune response, (3) isolation of culturable bacteria associated with feeding larvae, (4) quantification of larval associations with isolated bacterial strains and (5) preparation of secreted products from isolated bacteria for testing in larval culture.
Collapse
Affiliation(s)
- Katherine M Buckley
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States
| | - Nicholas W Schuh
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Andreas Heyland
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Jonathan P Rast
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Emory University School of Medicine, Pathology and Laboratory Medicine, Atlanta, GA, United States.
| |
Collapse
|
13
|
Cai J, Nichols RG, Koo I, Kalikow ZA, Zhang L, Tian Y, Zhang J, Smith PB, Patterson AD. Multiplatform Physiologic and Metabolic Phenotyping Reveals Microbial Toxicity. mSystems 2018; 3:e00123-18. [PMID: 30417115 PMCID: PMC6222046 DOI: 10.1128/msystems.00123-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/11/2018] [Indexed: 02/06/2023] Open
Abstract
The gut microbiota is susceptible to modulation by environmental stimuli and therefore can serve as a biological sensor. Recent evidence suggests that xenobiotics can disrupt the interaction between the microbiota and host. Here, we describe an approach that combines in vitro microbial incubation (isolated cecal contents from mice), flow cytometry, and mass spectrometry- and 1H nuclear magnetic resonance (NMR)-based metabolomics to evaluate xenobiotic-induced microbial toxicity. Tempol, a stabilized free radical scavenger known to remodel the microbial community structure and function in vivo, was studied to assess its direct effect on the gut microbiota. The microbiota was isolated from mouse cecum and was exposed to tempol for 4 h under strict anaerobic conditions. The flow cytometry data suggested that short-term tempol exposure to the microbiota is associated with disrupted membrane physiology as well as compromised metabolic activity. Mass spectrometry and NMR metabolomics revealed that tempol exposure significantly disrupted microbial metabolic activity, specifically indicated by changes in short-chain fatty acids, branched-chain amino acids, amino acids, nucleotides, glucose, and oligosaccharides. In addition, a mouse study with tempol (5 days gavage) showed similar microbial physiologic and metabolic changes, indicating that the in vitro approach reflected in vivo conditions. Our results, through evaluation of microbial viability, physiology, and metabolism and a comparison of in vitro and in vivo exposures with tempol, suggest that physiologic and metabolic phenotyping can provide unique insight into gut microbiota toxicity. IMPORTANCE The gut microbiota is modulated physiologically, compositionally, and metabolically by xenobiotics, potentially causing metabolic consequences to the host. We recently reported that tempol, a stabilized free radical nitroxide, can exert beneficial effects on the host through modulation of the microbiome community structure and function. Here, we investigated a multiplatform phenotyping approach that combines high-throughput global metabolomics with flow cytometry to evaluate the direct effect of tempol on the microbiota. This approach may be useful in deciphering how other xenobiotics directly influence the microbiota.
Collapse
Affiliation(s)
- Jingwei Cai
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Robert G. Nichols
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Imhoi Koo
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Zachary A. Kalikow
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Limin Zhang
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
- CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Centre for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS), Wuhan, China
| | - Yuan Tian
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
- CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Centre for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS), Wuhan, China
| | - Jingtao Zhang
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Philip B. Smith
- Metabolomics Facility, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Andrew D. Patterson
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| |
Collapse
|
14
|
Dagher Z, Xu S, Negoro PE, Khan NS, Feldman MB, Reedy JL, Tam JM, Sykes DB, Mansour MK. Fluorescent Tracking of Yeast Division Clarifies the Essential Role of Spleen Tyrosine Kinase in the Intracellular Control of Candida glabrata in Macrophages. Front Immunol 2018; 9:1058. [PMID: 29868018 PMCID: PMC5964189 DOI: 10.3389/fimmu.2018.01058] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/27/2018] [Indexed: 01/07/2023] Open
Abstract
Macrophages play a critical role in the elimination of fungal pathogens. They are sensed via cell surface pattern-recognition receptors and are phagocytosed into newly formed organelles called phagosomes. Phagosomes mature through the recruitment of proteins and lysosomes, resulting in addition of proteolytic enzymes and acidification of the microenvironment. Our earlier studies demonstrated an essential role of Dectin-1-dependent activation of spleen tyrosine kinase (Syk) in the maturation of fungal containing phagosomes. The absence of Syk activity interrupted phago-lysosomal fusion resulting in arrest at an early phagosome stage. In this study, we sought to define the contribution of Syk to the control of phagocytosed live Candida glabrata in primary macrophages. To accurately measure intracellular yeast division, we designed a carboxyfluorescein succinimidyl ester (CFSE) yeast division assay in which bright fluorescent parent cells give rise to dim daughter cells. The CFSE-labeling of C. glabrata did not affect the growth rate of the yeast. Following incubation with macrophages, internalized CFSE-labeled C. glabrata were retrieved by cellular lysis, tagged using ConA-647, and the amount of residual CFSE fluorescence was assessed by flow cytometry. C. glabrata remained undivided (CFSE bright) for up to 18 h in co-culture with primary macrophages. Treatment of macrophages with R406, a specific Syk inhibitor, resulted in loss of intracellular control of C. glabrata with initiation of division within 4 h. Delayed Syk inhibition after 8 h was less effective indicating that Syk is critically required at early stages of macrophage–fungal interaction. In conclusion, we demonstrate a new method of tracking division of C. glabrata using CFSE labeling. Our results suggest that early Syk activation is essential for macrophage control of phagocytosed C. glabrata.
Collapse
Affiliation(s)
- Zeina Dagher
- Division of Infectious Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Shuying Xu
- Division of Infectious Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Paige E Negoro
- Division of Infectious Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Nida S Khan
- Division of Infectious Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.,Biomedical Engineering and Biotechnology, University of Massachusetts Medical School, Worcester, MA, United States
| | - Michael B Feldman
- Division of Pulmonary and Critical Care, Massachusetts General Hospital, Boston, MA, United States
| | - Jennifer L Reedy
- Division of Infectious Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Jenny M Tam
- Division of Infectious Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - David B Sykes
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, United States
| | - Michael K Mansour
- Division of Infectious Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| |
Collapse
|
15
|
Ding T, Liao XY, Dong QL, Xuan XT, Chen SG, Ye XQ, Liu DH. Predictive modeling of microbial single cells: A review. Crit Rev Food Sci Nutr 2017; 58:711-725. [DOI: 10.1080/10408398.2016.1217193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Tian Ding
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xin-Yu Liao
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Qing-Li Dong
- Institute of Food Quality and Safety, University of Shanghai for Science and Technology, Shanghai, China
| | - Xiao-Ting Xuan
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shi-Guo Chen
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xing-Qian Ye
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Dong-Hong Liu
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| |
Collapse
|
16
|
Mathur H, Fallico V, O'Connor PM, Rea MC, Cotter PD, Hill C, Ross RP. Insights into the Mode of Action of the Sactibiotic Thuricin CD. Front Microbiol 2017; 8:696. [PMID: 28473822 PMCID: PMC5397516 DOI: 10.3389/fmicb.2017.00696] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/05/2017] [Indexed: 12/28/2022] Open
Abstract
Thuricin CD is a two-component bacteriocin, consisting of the peptides Trnα and Trnβ, and belongs to the newly designated sactibiotic subclass of bacteriocins. While it is clear from studies conducted thus far that it is a narrow-spectrum bacteriocin, requiring the synergistic activity of the two peptides, the precise mechanism of action of thuricin CD has not been elucidated. This study used a combination of flow cytometry and traditional culture-dependent assays to ascertain the effects of the thuricin CD peptides on the morphology, physiology and viability of sensitive Bacillus firmus DPC6349 cells. We show that both Trnα and Trnβ are membrane-acting and cause a collapse of the membrane potential, which could not be reversed even under membrane-repolarizing conditions. Furthermore, the depolarizing action of thuricin CD is accompanied by reductions in cell size and granularity, producing a pattern of physiological alterations in DPC6349 cells similar to those triggered by the pore-forming single-component bacteriocin Nisin A, and two-component lacticin 3147. Taken together, these results lead us to postulate that the lytic activity of thuricin CD involves the insertion of thuricin CD peptides into the membrane of target cells leading to permeabilization due to pore formation and consequent flux of ions across the membrane, resulting in membrane depolarization and eventual cell death.
Collapse
Affiliation(s)
- Harsh Mathur
- Moorepark Food Research CentreCounty Cork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | | | | | - Mary C Rea
- Moorepark Food Research CentreCounty Cork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | - Paul D Cotter
- Moorepark Food Research CentreCounty Cork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | - Colin Hill
- APC Microbiome Institute, University College CorkCork, Ireland.,School of Microbiology, University College CorkCork, Ireland
| | - R Paul Ross
- Moorepark Food Research CentreCounty Cork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland.,School of Microbiology, University College CorkCork, Ireland
| |
Collapse
|
17
|
Chung S, Kim SH, Seo Y, Kim SK, Lee JY. Quantitative analysis of cell proliferation by a dye dilution assay: Application to cell lines and cocultures. Cytometry A 2017; 91:704-712. [PMID: 28375566 DOI: 10.1002/cyto.a.23105] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 03/05/2017] [Accepted: 03/09/2017] [Indexed: 12/13/2022]
Abstract
Cell proliferation represents one of the most fundamental processes in biological systems, thus the quantitative analysis of cell proliferation is important in many biological applications such as drug screening, production of biologics, and assessment of cytotoxicity. Conventional proliferation assays mainly quantify cell number based on a calibration curve of a homogeneous cell population, and therefore are not applicable for the analysis of cocultured cells. Moreover, these assays measure cell proliferation indirectly, based on cellular metabolic activity or DNA content. To overcome these shortcomings, a dye dilution assay employing fluorescent cell tracking dyes that are retained within cells was applied and was diluted proportionally by subsequent cell divisions. Here, it was demonstrated that this assay could be implemented to quantitatively analyze the cell proliferation of different types of cell lines, and to concurrently analyze the proliferation of two types of cell lines in coculture by utilizing cell tracking dyes with different spectral characteristics. The mean division time estimated by the dye dilution assay is compared with the population doubling time obtained from conventional methods and values from literature. Additionally, dye transfer between cocultured cells was investigated and it was found that it is a characteristic of the cells rather than a characteristic of the dye. It was suggested that this method can be easily combined with other flow cytometric analyses of cellular properties, providing valuable information on cell status under diverse conditions. © 2017 International Society for Advancement of Cytometry.
Collapse
Affiliation(s)
- Soobin Chung
- Center for Bioanalysis, Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea.,Department of Bio-Analytical Science, University of Science and Technology, 217 Gajeong-ro, Youseong-gu, Daejeon, 34113, Republic of Korea
| | - Seol-Hee Kim
- Center for Bioanalysis, Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea
| | - Yuri Seo
- Center for Bioanalysis, Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea
| | - Sook-Kyung Kim
- Center for Bioanalysis, Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea.,Department of Bio-Analytical Science, University of Science and Technology, 217 Gajeong-ro, Youseong-gu, Daejeon, 34113, Republic of Korea
| | - Ji Youn Lee
- Center for Bioanalysis, Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea
| |
Collapse
|
18
|
Hansen G, Johansen CL, Honoré AH, Jensen HM, Jespersen L, Arneborg N. Fluorescent labelling negatively affects the physiology of Lactococcus lactis. Int Dairy J 2015. [DOI: 10.1016/j.idairyj.2015.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
19
|
Bhardwaj V, Dhungyel O, de Silva K, Whittington RJ. Investigation of immunity in sheep following footrot infection and vaccination. Vaccine 2014; 32:6979-6985. [PMID: 25454866 DOI: 10.1016/j.vaccine.2014.10.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 10/07/2014] [Accepted: 10/16/2014] [Indexed: 11/17/2022]
Abstract
Ovine footrot is a major disease affecting sheep welfare and production. The anaerobic Gram-negative bacterium Dichelobacter nodosus is the essential transmitting agent. Monovalent or bivalent vaccines induce high levels of D. nodosus antibodies and are the basis of several successful footrot treatment, control and eradication programs. Due to the rapid rate of disease transmission within a flock, the presence of therapeutic vaccination non-responders has major implications for a control program. The aim of this study was to assess the immunological basis of a therapeutic vaccination non-response. Sheep (n=120) were infected with D. nodosus in an artificial pen challenge. Once disease had established, animals were vaccinated with a serogroup specific D. nodosus fimbrial vaccine. Based on the response to therapeutic vaccination, animals were allocated into one of three groups: (i) TVNR where disease persisted despite vaccination (ii) non-diseased, where disease never established and (iii) TVR, where disease was established but resolved with vaccination. Factors related to both the innate and adaptive immune pathways were assessed. These included antigen-specific serum antibodies, interferon-γ, interleukin-10, proliferation of lymphocyte subsets and phagocytic activity of leukocytes. There was no significant difference between the three groups of sheep for any of these parameters. All three groups of sheep produced antibody in excess of a previously published minimum antibody titre required for protection. Opsonising activity in sera from the three groups of sheep was also not significantly different and phagocytic cells from sheep from all three groups were able to destroy D. nodosus intracellularly. These findings show that the measured systemic adaptive and innate immune responses were unlikely to be the cause of a therapeutic vaccination non-response. They also show that the accepted minimum protective titre may be incorrect and may need further examination.
Collapse
Affiliation(s)
- Vidya Bhardwaj
- Farm Animal and Veterinary Public Health, Faculty of Veterinary Science, University of Sydney, 425 Werombi Road, Camden 2570, NSW, Australia
| | - Om Dhungyel
- Farm Animal and Veterinary Public Health, Faculty of Veterinary Science, University of Sydney, 425 Werombi Road, Camden 2570, NSW, Australia
| | - Kumudika de Silva
- Farm Animal and Veterinary Public Health, Faculty of Veterinary Science, University of Sydney, 425 Werombi Road, Camden 2570, NSW, Australia.
| | - Richard J Whittington
- Farm Animal and Veterinary Public Health, Faculty of Veterinary Science, University of Sydney, 425 Werombi Road, Camden 2570, NSW, Australia
| |
Collapse
|
20
|
Zuehlke JM, Edwards CG. Impact of sulfur dioxide and temperature on culturability and viability of Brettanomyces bruxellensis in Wine. J Food Prot 2013; 76:2024-30. [PMID: 24290676 DOI: 10.4315/0362-028x.jfp-13-243r] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Brettanomyces is a major threat to red wine quality, causing off-odors such as "medicinal," "barnyard," or even "sewage" during aging. Although sulfites (SO2) are used to limit spoilage by these yeast cells, reduced storage temperatures may lessen SO2 requirements. To test this hypothesis, a 4 | 4 factorial experimental design with molecular SO2(mSO2) concentration (0.0, 0.2, 0.5, or 1.1 mg/liter) and storage temperature (22, 18, 15, or 10°C) was devised. Of three strains evaluated, B5 was the lone strain to regain culturability following exposure to 0.5 mg/liter mSO2 (18°C), whereas only F3 remained culturable in the absence of mSO2 at 10°C. Application of fluorescence microscopy using two different probes and quantitative PCR assays revealed only a 2-log reduction in metabolically active cells from wines with SO2 that were not culturable on nonselective media. Culturability in these wines eventually returned regardless of the concentration of mSO2 present. In addition, 4-ethylphenol production ceased upon addition of SO2. These findings provide additional support that Brettanomyces can enter a "viable-but-not-culturable" state upon exposure to sulfites. Given the diversity among strains, maintaining conditions of ≤15°C and ≥0.4 mg/liter mSO2 will help limit spoilage by Brettanomyces but will not lead to its complete eradication.
Collapse
Affiliation(s)
- Jesse M Zuehlke
- School of Food Science, Washington State University, Pullman, Washington 99164-6376, USA.
| | | |
Collapse
|
21
|
Chadli L, Cadio E, Vaigot P, Martin MT, Fortunel NO. Monitoring the cycling activity of cultured human keratinocytes using a CFSE-based dye tracking approach. Methods Mol Biol 2013; 989:83-97. [PMID: 23483389 DOI: 10.1007/978-1-62703-330-5_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The development of methods and tools suitable for functional analysis of keratinocytes placed in an in vitro context is of great importance for characterizing properties associated with their normal state, for detecting abnormalities related to pathological states, or for studying the effects of extrinsic factors. In the present chapter, we describe the use of the intracellular fluorescent dye carboxyfluorescein succinimidyl ester (CFSE) to monitor cell division in mass cultures of normal human keratinocytes. We detail the preparation of CFSE-labeled keratinocyte samples and the identification by flow cytometry of cell subpopulations exhibiting different cycling rates in a mitogenic culture context. In addition, we show that the CFSE-based division-tracking approach enables the monitoring of keratinocyte responsiveness to growth modulators, which is here exemplified by the cell-cycling inhibition mediated by the growth factor TGF-β1. Finally, we show that keratinocyte subpopulations, separated according to their mitotic history using CFSE fluorescence tracking, can be sorted by flow cytometry and used for further functional characterization, including determination of clone-forming efficiency.
Collapse
Affiliation(s)
- Loubna Chadli
- Laboratory of Genomics and Radiobiology of Keratinopoiesis (LGRK), Institute of Cellular and Molecular Radiobiology (iRCM), Alternative Energies and Atomic Energy Commission (CEA), Evry, France
| | | | | | | | | |
Collapse
|
22
|
Lyons AB, Blake SJ, Doherty KV. Flow cytometric analysis of cell division by dilution of CFSE and related dyes. CURRENT PROTOCOLS IN CYTOMETRY 2013; Chapter 9:9.11.1-9.11.12. [PMID: 23546777 DOI: 10.1002/0471142956.cy0911s64] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The technique described in this unit uses the intracellular fluorescent label carboxyfluorescein diacetate succinimidyl ester (CFSE) to track proliferating cells. Covalently bound CFSE is divided equally between daughter cells, allowing discrimination of successive rounds of cell division. The technique is applicable to in vitro cell division, as well as to in vivo division of adoptively transferred cells and can resolve eight or more successive generations. CFSE is long lived, permitting analysis for several months after cell transfer, and has the same spectral characteristics as fluorescein, so monoclonal antibodies conjugated to phycoerythrin or other compatible fluorochromes may be used to immunophenotype the dividing cells. In addition, information is given on a second-generation dye, Cell Trace Violet (CTV), excited by 405-nm blue laser light. CTV is chemically related to CFSE, but allows the 488-nm line of the Argon laser to be used for other probes.
Collapse
Affiliation(s)
- A Bruce Lyons
- School of Medicine, The University of Tasmania, Hobart, Tasmania, Australia
| | - Stephen J Blake
- Diamantina Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Kathleen V Doherty
- Faculty of Health Science, The University of Tasmania, Hobart, Tasmania, Australia
| |
Collapse
|
23
|
Karimi K, Kandiah N, Chau J, Bienenstock J, Forsythe P. A Lactobacillus rhamnosus strain induces a heme oxygenase dependent increase in Foxp3+ regulatory T cells. PLoS One 2012; 7:e47556. [PMID: 23077634 PMCID: PMC3471882 DOI: 10.1371/journal.pone.0047556] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 09/18/2012] [Indexed: 02/07/2023] Open
Abstract
We investigated the consequences of feeding with a Lactobacillus species on the immune environment in GALT, and the role of dendritic cells and heme oxygenase-1 in mediating these responses. Feeding with a specific strain of Lactobacillus rhamnosus induced a significant increase in CD4+CD25+Foxp3+ functional regulatory T cells in GALT. This increase was greatest in the mesenteric lymph nodes and associated with a marked decrease in TNF and IFNγ production. Dendritic cell regulatory function and HO-1 expression was also increased. The increase in Foxp3+ T cells could be prevented by treatment with a heme oxygenase inhibitor. However, neither inhibition of heme oxygenase nor blockade of IL-10 and TGFβ prevented the inhibition of inflammatory cytokine production. In conclusion Lactobacillus feeding induced a tolerogenic environment in GALT. HO-1 was critical to the enhancement of Foxp3+ regulatory T cells while additional, as yet unknown, pathways were involved in the down-regulation of inflammatory cytokine production by T cells.
Collapse
Affiliation(s)
- Khalil Karimi
- The Brain Body institute, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- * E-mail: (PF); (KK)
| | - Nalaayini Kandiah
- The Brain Body institute, McMaster University, Hamilton, Ontario, Canada
| | - Jessie Chau
- The Brain Body institute, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - John Bienenstock
- The Brain Body institute, McMaster University, Hamilton, Ontario, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Paul Forsythe
- The Brain Body institute, McMaster University, Hamilton, Ontario, Canada
- Firestone Institute for Respiratory Health, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- * E-mail: (PF); (KK)
| |
Collapse
|
24
|
UMIKER N, DESCENZO R, LEE J, EDWARDS C. REMOVAL OFBRETTANOMYCES BRUXELLENSISFROM RED WINE USING MEMBRANE FILTRATION. J FOOD PROCESS PRES 2012. [DOI: 10.1111/j.1745-4549.2012.00702.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
25
|
Experimental methods and modeling techniques for description of cell population heterogeneity. Biotechnol Adv 2011; 29:575-99. [DOI: 10.1016/j.biotechadv.2011.03.007] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 02/04/2011] [Accepted: 03/31/2011] [Indexed: 11/24/2022]
|
26
|
Orally administered Bifidobacterium triggers immune responses following capture by CD11c(+) cells in Peyer's patches and cecal patches. Cytotechnology 2011; 63:307-17. [PMID: 21461945 DOI: 10.1007/s10616-011-9349-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2010] [Accepted: 02/24/2011] [Indexed: 10/18/2022] Open
Abstract
We have investigated the immunomodulatory mechanisms of Bifidobacterium pseudocatenulatum JCM7041 (Bp) as model of probiotics following oral administration to mice. This study was conducted with the aim of clarifying the mechanism of immunomodulation induced by oral administration of probiotic bacteria through elucidation of the detailed mechanism of transfer of orally administered bacterial cells within the body and the interaction between bacterial cells and cells of the immune tissues. We observed the localization of Bp in mice following oral administration, showing that Bp was surrounded by CD11c(+) cells in Peyer's patches (PP) and cecal patches (CP). These results indicated that Bp might induce CD11c(+) cell-mediated immune responses directly. Furthermore, IL-10 and IL-12p40 production by Thy1.2(-) cells, including CD11c(+) cells, increased significantly. Production of IL-10 and IL-12p40 by bone marrow-derived dendritic cells (BMDC) was significantly increased by Bp stimulation. These results suggest that oral administration of Bp induces immune responses directly following capture by CD11c(+) dendritic cells (DCs). Subsequently, we observed oral administration of Bp for 1 week induced IgA and IgA-associated cytokine production by CP and PP cells, suggesting that Bp induced DC-mediated immune responses on CP as well as PP.
Collapse
|
27
|
Bester E, Kroukamp O, Hausner M, Edwards E, Wolfaardt G. Biofilm form and function: carbon availability affects biofilm architecture, metabolic activity and planktonic cell yield. J Appl Microbiol 2010; 110:387-98. [DOI: 10.1111/j.1365-2672.2010.04894.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
28
|
Baumstummler A, Chollet R, Meder H, Olivieri F, Rouillon S, Waiche G, Ribault S. Development of a nondestructive fluorescence-based enzymatic staining of microcolonies for enumerating bacterial contamination in filterable products. J Appl Microbiol 2010; 110:69-79. [PMID: 20880209 DOI: 10.1111/j.1365-2672.2010.04859.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Develop a nondestructive fluorescence-based staining procedure to rapidly detect and enumerate bacteria in filterable samples. METHODS AND RESULTS The study consists in the development of a staining solution and a protocol to fluorescently detect microcolonies on cellulose membranes. After detection, membranes can be re-incubated on media to yield colonies. Carboxyfluorescein diacetate was selected among other carboxyfluorescein derivatives for its staining efficiency and the absence of background. Several permeabilizers were evaluated for their ability to promote dye uptake into cells without affecting viability. We demonstrated that a combination of n-Octyl β-D-glucopyranoside, sodium hexametaphosphate, lithium chloride and rubidium chloride significantly increased the staining efficiency of bacteria without affecting their viability. The method developed allowed the detection in <9 h of all tested aerobic bacteria and in 48 h of the anaerobic slow grower Propionibacterium acnes. CONCLUSIONS This method allows the rapid detection of bacteria in filterable samples in at least three to five times faster than traditional microbiological method. SIGNIFICANCE AND IMPACT OF THE STUDY The advantage of this nondestructive procedure is to allow contaminants identification after membrane re-incubation. This method could be easily applied in routine in pharmaceutical, clinical and food and beverage industries to monitor contaminations.
Collapse
Affiliation(s)
- A Baumstummler
- Millipore, Bioprocess Division, Process Monitoring Tools, Applied Biology R&D Department, Molsheim, France.
| | | | | | | | | | | | | |
Collapse
|
29
|
Müller S, Nebe-von-Caron G. Functional single-cell analyses: flow cytometry and cell sorting of microbial populations and communities. FEMS Microbiol Rev 2010; 34:554-87. [DOI: 10.1111/j.1574-6976.2010.00214.x] [Citation(s) in RCA: 266] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
|
30
|
Díaz M, Herrero M, García LA, Quirós C. Application of flow cytometry to industrial microbial bioprocesses. Biochem Eng J 2010. [DOI: 10.1016/j.bej.2009.07.013] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
31
|
Inhibitory effect of caprylic acid and mild heat on Cronobacter spp. (Enterobacter sakazakii) in reconstituted infant formula and determination of injury by flow cytometry. Int J Food Microbiol 2009; 133:113-20. [DOI: 10.1016/j.ijfoodmicro.2009.05.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2009] [Revised: 04/21/2009] [Accepted: 05/03/2009] [Indexed: 11/21/2022]
|
32
|
Parish CR, Glidden MH, Quah BJC, Warren HS. Use of the intracellular fluorescent dye CFSE to monitor lymphocyte migration and proliferation. CURRENT PROTOCOLS IN IMMUNOLOGY 2009; Chapter 4:4.9.1-4.9.13. [PMID: 19235770 DOI: 10.1002/0471142735.im0409s84] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The stable incorporation of the intracellular fluorescent dye 5-(and -6)-carboxyfluorescein diacetate succinimidyl ester (CFSE) into cells provides a powerful tool to monitor cell migration, and to quantify cell division, because of the sequential decrease in fluorescent labeling in daughter cells. CFSE-labeled lymphocytes have been used to analyze the relationship between cell division and differentiation of cell function, and cell proliferation versus apoptosis, both in vivo and in vitro, and have allowed analysis of the site of response to antigens in vivo.
Collapse
Affiliation(s)
| | | | - Ben J C Quah
- Australian National University, Canberra, Australia
| | | |
Collapse
|
33
|
Shen T, Bos AP, Brul S. Assessing freeze–thaw and high pressure low temperature induced damage to Bacillus subtilis cells with flow cytometry. INNOV FOOD SCI EMERG 2009. [DOI: 10.1016/j.ifset.2008.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
34
|
Cronin UP, Wilkinson MG. Physiological response of Bacillus cereus vegetative cells to simulated food processing treatments. J Food Prot 2008; 71:2168-76. [PMID: 19044257 DOI: 10.4315/0362-028x-71.11.2168] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Vegetative cells of the spore-former Bacillus cereus were exposed to a number of treatments commonly used in commercial food preparation or during equipment cleaning and decontamination. Treated suspensions were then analyzed for reductions (CFU per milliliter) by plate counting and changes in levels of ATP and ADP released from cells with a bioluminescence-based assay. With the use of flow cytometry (FCM), the physiological status of individual cells before and after exposure to treatments was determined by staining of control and treated cells with three pairs of physiological dyes (SYTO 9/propidium iodide, carboxyfluorescein diacetate/Hoechst 33342, and C12-resazurin/SYTOX Green). Good agreement was found between plate counting and FCM. In general, treatments giving rise to the highest count reductions also had the greatest effects on cell membrane permeability (measured with the use of propidium iodide or SYTOX Green), esterase activity (measured with carboxyfluorescein diacetate), or redox activity (C12-resazurin). FCM data demonstrated the extent of heterogeneity of vegetative cell responses to treatments in, for example, the treatment with 5% H2O2, which caused a 6-log reduction in which approximately 95% of the population was composed of membrane-damaged cells (as reflected by their permeability to SYTOX Green), whereas in treatment with 0.09% (wt/vol) potassium sorbate, which caused only a 1-log reduction, not more than 40% of cells were membrane damaged. The approaches described in this work can be applied to gain a greater understanding of bacterial responses to food control measures, generate more accurate inactivation models, or screen novel prospective food control measures.
Collapse
Affiliation(s)
- Ultan P Cronin
- Department of Life Sciences, University of Limerick, Castletroy, County Limerick, Ireland
| | | |
Collapse
|
35
|
Smelt J, Bos A, Kort R, Brul S. Modelling the effect of sub(lethal) heat treatment of Bacillus subtilis spores on germination rate and outgrowth to exponentially growing vegetative cells. Int J Food Microbiol 2008; 128:34-40. [DOI: 10.1016/j.ijfoodmicro.2008.08.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 08/29/2008] [Accepted: 08/29/2008] [Indexed: 10/21/2022]
|
36
|
Quirós C, Herrero M, García LA, Díaz M. Taking advantage of the flow cytometry technique for improving malolactic starters production. Eur Food Res Technol 2008. [DOI: 10.1007/s00217-008-0961-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
37
|
Monitoring growth phase-related changes in phosphatidylcholine-specific phospholipase C production, adhesion properties and physiology of Bacillus cereus vegetative cells. J Ind Microbiol Biotechnol 2008; 35:1695-703. [DOI: 10.1007/s10295-008-0461-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 08/06/2008] [Indexed: 10/21/2022]
|
38
|
Gangoiti P, Granado MH, Wang SW, Kong JY, Steinbrecher UP, Gómez-Muñoz A. Ceramide 1-phosphate stimulates macrophage proliferation through activation of the PI3-kinase/PKB, JNK and ERK1/2 pathways. Cell Signal 2007; 20:726-36. [PMID: 18234473 DOI: 10.1016/j.cellsig.2007.12.008] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Revised: 12/11/2007] [Accepted: 12/12/2007] [Indexed: 12/11/2022]
Abstract
Ceramide 1-phosphate (C1P) was first shown to be mitogenic for fibroblasts, but the mechanisms whereby it stimulated cell proliferation have remained largely unknown. Here we demonstrate that C1P stimulates DNA synthesis and cell division in murine bone marrow-derived macrophages. C1P caused rapid phosphorylation of protein kinase B (PKB, also known as Akt), a downstream target of phosphatidylinositol 3-kinase (PI3-K). Selective inhibition of PI3-K blocked both DNA synthesis and cell growth. C1P induced phosphorylation of GSK-3beta, which is a major target of PKB, and this effect was also abolished by inhibition of PI3-K. In addition, C1P upregulated the expression of cyclin D1 and c-Myc, two major targets of GSK-3beta, which are important regulators of cell proliferation. C1P stimulated the activity of NF-kappaB, and inhibitors of this transcription factor completely blocked macrophage proliferation. Lastly, C1P induced phosphorylation of the mitogen activated protein kinases (MAPK) extracellularly regulated kinases 1 and 2 (ERK1/2), and c-Jun N-terminal kinase (JNK). Inhibition of ERK1/2 and JNK also blocked C1P-induced macrophage proliferation. It can be concluded that C1P stimulates macrophage proliferation through activation of the PI3-K/PKB, ERK and JNK pathways, and that GSK-3beta, c-Myc, cyclin D1, and NF-kappaB are important downstream effectors in this action.
Collapse
Affiliation(s)
- Patricia Gangoiti
- Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain
| | | | | | | | | | | |
Collapse
|
39
|
Quah BJC, Warren HS, Parish CR. Monitoring lymphocyte proliferation in vitro and in vivo with the intracellular fluorescent dye carboxyfluorescein diacetate succinimidyl ester. Nat Protoc 2007; 2:2049-56. [PMID: 17853860 DOI: 10.1038/nprot.2007.296] [Citation(s) in RCA: 444] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This protocol outlines the carboxyfluorescein diacetate succinimidyl ester (CFSE) method for following the proliferation of human lymphocytes in vitro and mouse lymphocytes both in vitro and in vivo. The method relies on the ability of CFSE to covalently label long-lived intracellular molecules with the highly fluorescent dye, carboxyfluorescein. Following each cell division, the equal distribution of these fluorescent molecules to progeny cells results in a halving of the fluorescence of daughter cells. The CFSE labeling protocol described, which typically takes <1 h to perform, allows the detection of up to eight cell divisions before CFSE fluorescence is decreased to the background fluorescence of unlabeled cells. Protocols are outlined for labeling large and small numbers of human and mouse lymphocytes, labeling conditions being identified that minimize CFSE toxicity but maximize the number of cell divisions detected. An important feature of the technique is that division-dependent changes in the expression of cell-surface markers and intracellular proteins are easily quantified by flow cytometry.
Collapse
Affiliation(s)
- Ben J C Quah
- Division of Immunology and Genetics, John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | | | | |
Collapse
|
40
|
Brizuela L, Rábano M, Gangoiti P, Narbona N, Macarulla JM, Trueba M, Gómez-Muñoz A. Sphingosine-1-phosphate stimulates aldosterone secretion through a mechanism involving the PI3K/PKB and MEK/ERK 1/2 pathways. J Lipid Res 2007; 48:2264-74. [PMID: 17609523 DOI: 10.1194/jlr.m700291-jlr200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We reported recently that sphingosine-1-phosphate (S1P) is a novel regulator of aldosterone secretion in zona glomerulosa cells of adrenal glands and that phospholipase D (PLD) is implicated in this process. We now show that S1P causes the phosphorylation of protein kinase B (PKB) and extracellularly regulated kinases 1/2 (ERK 1/2), which is an indication of their activation, in these cells. These effects are probably mediated through the interaction of S1P with the Gi protein-coupled receptors S1P1/3, as pretreatment with pertussis toxin or with the S1P1/3 antagonist VPC 23019 completely abolished the phosphorylation of these kinases. Inhibitors of phosphatidylinositol 3-kinase (PI3K) or mitogen-activated protein kinase kinase (MEK) blocked S1P-stimulated aldosterone secretion. This inhibition was only partial when the cells were incubated independently with inhibitors of each pathway. However, aldosterone output was completely blocked when the cells were pretreated with LY 294002 and PD 98059 simultaneously. These inhibitors also blocked PLD activation, which indicates that this enzyme is downstream of PI3K and MEK in this system. We propose a working model for S1P in which stimulation of the PI3K/PKB and MEK/ERK pathways leads to the stimulation of PLD and aldosterone secretion.
Collapse
Affiliation(s)
- Leyre Brizuela
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, 48080, Bilbao, Spain
| | | | | | | | | | | | | |
Collapse
|
41
|
Yates A, Chan C, Strid J, Moon S, Callard R, George AJT, Stark J. Reconstruction of cell population dynamics using CFSE. BMC Bioinformatics 2007; 8:196. [PMID: 17565685 PMCID: PMC1929124 DOI: 10.1186/1471-2105-8-196] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Accepted: 06/12/2007] [Indexed: 11/17/2022] Open
Abstract
Background Quantifying cell division and death is central to many studies in the biological sciences. The fluorescent dye CFSE allows the tracking of cell division in vitro and in vivo and provides a rich source of information with which to test models of cell kinetics. Cell division and death have a stochastic component at the single-cell level, and the probabilities of these occurring in any given time interval may also undergo systematic variation at a population level. This gives rise to heterogeneity in proliferating cell populations. Branching processes provide a natural means of describing this behaviour. Results We present a likelihood-based method for estimating the parameters of branching process models of cell kinetics using CFSE-labeling experiments, and demonstrate its validity using synthetic and experimental datasets. Performing inference and model comparison with real CFSE data presents some statistical problems and we suggest methods of dealing with them. Conclusion The approach we describe here can be used to recover the (potentially variable) division and death rates of any cell population for which division tracking information is available.
Collapse
Affiliation(s)
- Andrew Yates
- Department of Biology, Emory University, 1510 Clifton Road, Atlanta, GA 30322, USA
| | - Cliburn Chan
- Department of Biostatistics and Bioinformatics, Duke University Laboratory of Computational Immunology, 106 North Bldg, Research Drive, Box 90090, Durham, NC 27708, USA
| | - Jessica Strid
- Peter Gorer Department of Immunobiology, Guy's, King's and St Thomas' School of Medicine, King's College London, Guy's Hospital, London SE1 9RT, UK
| | - Simon Moon
- Department of Mathematics, Imperial College London, 180 Queen's Gate, London SW7 2BZ, UK
- Centre for Integrative Systems Biology at Imperial College (CISBIC), UK
| | - Robin Callard
- Immunobiology Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Andrew JT George
- Department of Immunology, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Jaroslav Stark
- Department of Mathematics, Imperial College London, 180 Queen's Gate, London SW7 2BZ, UK
- Centre for Integrative Systems Biology at Imperial College (CISBIC), UK
| |
Collapse
|
42
|
Fendel R, Mordmüller B, Kreidenweiss A, Rudat A, Steur C, Ambrosch C, Kirstein M, Berdel WE, Kremsner PG, Brandts C. New method to quantify erythrophagocytosis by autologous monocytes. Cytometry A 2007; 71:258-64. [PMID: 17342773 DOI: 10.1002/cyto.a.20360] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Anemia is the net result of decreased red blood cell (RBC) production and increased removal of RBCs. Replication and maturation of erythroid precursors and RBC lysis can be measured by standardized in vitro methods and surrogate markers, respectively. In contrast, erythrophagocytosis by autologous phagocytes is more difficult to quantify. METHODS We developed a method to assess erythrophagocytosis by autologous monocytes from 5 ml of whole blood. RBCs were labeled with carboxyfluorescein-diacetate-succinimidyl ester (CFDA-SE) and subsequently coincubated with autologous CD14(+) monocytes. Phagocytosis was quantified using flow cytometry. After standardization, the assay was validated in patients with severe malarial anemia (SMA), a condition that is associated with increased erythrophagocytosis. RESULTS After labeling, CFDA-SE was stably incorporated into RBCs and no significant leakage leading to contamination of nonlabeled cells was observed. Monocytes ingested opsonized, labeled RBCs seven times more than nonopsonized controls. Erythrophagocytosis was significantly higher in SMA than in healthy controls. CONCLUSIONS The established assay showed enhanced autoerythrophagocytosis associated with SMA and hence was able to detect clinically relevant erythrophagocytosis. This novel assay is well suited for rapid quantification of in vitro erythrophagocytosis by autologous monocytes.
Collapse
Affiliation(s)
- Rolf Fendel
- Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Thanh NV, Rombouts FM, Nout MJR. Viability and physiological state transitions of Rhizopus oligosporus sporangiospores in tempe starter culture. Antonie van Leeuwenhoek 2006; 91:35-44. [PMID: 17021939 DOI: 10.1007/s10482-006-9093-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Accepted: 05/16/2006] [Indexed: 10/24/2022]
Abstract
The viability and various physiological characteristics of individual sporangiospores of Rhizopus oligosporus in tempe starter cultures that had been stored for 8, 10, 16 and 30 months were examined by flow cytometry in combination with fluorescent dyes. Besides live, dead, and dormant spores we distinguished a category of sublethally damaged spores. Results indicated that the shelf-life of tempe starters was not limited by the death of spores, but by sublethal damage to spores as well as by dormancy which can be overcome by resuscitation, respiratory activation. During storage, the number of dormant and sublethally damaged spores increased: the longer the starter cultures were stored, the less dormant spores could still be activated. In contrast, the transition from sublethally damaged (spores that are not able to transform cFDA and emit green fluorescence except by activation treatment) to activated spores did not decrease with longer storage. However, after very long (30 months) storage, sublethally damaged spores could still be activated but could not germinate anymore. The shelf-life of spores in tempe starter is related to the physiological state of spores being sublethally damaged; a mechanism of physiological state transitions of R. oligosporus sporangiospores is proposed.
Collapse
Affiliation(s)
- Nguyen V Thanh
- Biotechnology Research and Development Institute, Can Tho University, Can Tho, Vietnam
| | | | | |
Collapse
|
44
|
Papadimitriou K, Pratsinis H, Nebe-von-Caron G, Kletsas D, Tsakalidou E. Rapid assessment of the physiological status of Streptococcus macedonicus by flow cytometry and fluorescence probes. Int J Food Microbiol 2006; 111:197-205. [PMID: 16934355 DOI: 10.1016/j.ijfoodmicro.2006.04.042] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Revised: 01/11/2006] [Accepted: 04/21/2006] [Indexed: 10/24/2022]
Abstract
Flow cytometry in combination with fluorescence probes was applied to rapidly assess the physiological status of Streptococcus macedonicus ACA-DC 198, a newly described member of the lactic acid bacteria group with technologically important features (e.g. lantibiotic production). A sonication procedure was developed for disaggregating typical streptococci chains in order to optimize cell preparations for single cell analysis. Single stained live and dead populations of S. macedonicus cells were clearly resolved based on membrane potential by bis-oxonol [DiBAC(4)(3)], membrane integrity by Propidium Iodide (PI) and enzymatic activity as well as membrane integrity by Carboxyfluorescein Diacetate (cFDA). Further, estimation of both live and dead cells by a cFDA/PI two-colour flow cytometric assay showed excellent correlation with the dead cells in the samples (dead(FCM)=0.9945 dead(S)-0.806, R(2)=0.9986 and live(FCM)=-0.978 dead(S)+98.895, R(2)=0.9992). Finally, the assay was applied to study the physiology of S. macedonicus after acid stress. Interestingly, in situ assessment of the physiological status of stressed S. macedonicus cells by flow cytometry and single cell sorting revealed the coexistence of three distinct subpopulations according to their fluorescence labelling behaviour and culturability, representing intact/culturable, permeabilized/dead and potentially injured cells with the latter exhibiting both metabolic activity and membrane permeabilization as well as decreased culturability.
Collapse
Affiliation(s)
- Konstantinos Papadimitriou
- Laboratory of Dairy Research, Department of Food Science and Technology, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece
| | | | | | | | | |
Collapse
|
45
|
Lee YK, Hao W, Ho PS, Nordling MM, Low CS, de Kok TMCM, Rafter J. Human fecal water modifies adhesion of intestinal bacteria to Caco-2 cells. Nutr Cancer 2006; 52:35-42. [PMID: 16091002 DOI: 10.1207/s15327914nc5201_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The aqueous phase of feces (fecal water) has been suggested to mediate the effects of diet on colon carcinogenesis. We determined whether human fecal water samples, of varying genotoxic potential, had the capacity to alter adhesion of intestinal bacteria to intestinal (Caco-2) cells. Genotoxicity of fecal water samples was measured using the single-cell gel electrophoresis assay ("comet" assay), and bacterial adhesion was measured using a well-established model system. Fecal water genotoxicity was found to correlate positively with inhibition of adhesion of Escherichia coli strains, Salmonella species, and Enterococcus faecium to Caco-2 cells. The presence of fecal water samples did not interfere with adhesion of Bacteroides and Lactobacillus species. Inhibition of adhesion by fecal water was not due to cytotoxicity to Caco-2 cells as cytotoxicities of most fecal water samples were similar, nor was the inhibitory effect due to bacteriotoxicity as toxicity of fecal waters in the 10 strains of bacteria studied was not detected. Results indicate that components in fecal water may alter adhesion of intestinal bacteria to intestinal cell surfaces and that this effect may be correlated to the genotoxic potential of fecal water. This may have consequences for dietary effects on colon carcinogenesis.
Collapse
Affiliation(s)
- Yuan-Kun Lee
- Department of Microbiology, Faculty of Medicine, National University of Singapore
| | | | | | | | | | | | | |
Collapse
|
46
|
Maukonen J, Alakomi HL, Nohynek L, Hallamaa K, Leppämäki S, Mättö J, Saarela M. Suitability of the fluorescent techniques for the enumeration of probiotic bacteria in commercial non-dairy drinks and in pharmaceutical products. Food Res Int 2006. [DOI: 10.1016/j.foodres.2005.05.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
47
|
Alakomi HL, Mättö J, Virkajärvi I, Saarela M. Application of a microplate scale fluorochrome staining assay for the assessment of viability of probiotic preparations. J Microbiol Methods 2005; 62:25-35. [PMID: 15823392 DOI: 10.1016/j.mimet.2005.01.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2004] [Revised: 01/13/2005] [Accepted: 01/13/2005] [Indexed: 10/25/2022]
Abstract
Cell viability in probiotic preparations is traditionally assessed by the plate count technique. Additionally, fluorescent staining combined with epifluorescence microscopy or flow cytometry has been developed for the viability assessment, but the currently available assays are either laborious or require highly sophisticated equipment. The aim of this study was to investigate the applicability of a microplate scale fluorochrome assay for predicting the cell state of freeze-dried Lactobacillus rhamnosus and Bifidobacterium animalis subsp. lactis preparations. In addition to viability assessment with LIVE/DEAD BacLight Bacterial Viability Kit, DiBAC(4)3 stain was used for the kinetic measurement of changes in bifidobacterial cell membrane functions during exposure to low pH. The microplate scale fluorochrome assay results on the viability and cell numbers of probiotic preparations correlated well with the results obtained with the culture-based technique and (with few exceptions) with epifluorescence microscopy. The assay was applicable also for the viability assessment of stressed (acid-treated) cells provided that the cell density in treatments was adjusted to the optimal measurement level of the fluorometer. The microplate scale fluorochrome assay offers a rapid and robust tool for the viability assessment of probiotic preparations, and enables also kinetic measurements.
Collapse
Affiliation(s)
- H-L Alakomi
- VTT Biotechnology, P.O. Box 1500, FIN-02044 VTT, Espoo, Finland.
| | | | | | | |
Collapse
|
48
|
Wang XQ, Duan XM, Liu LH, Fang YQ, Tan Y. Carboxyfluorescein diacetate succinimidyl ester fluorescent dye for cell labeling. Acta Biochim Biophys Sin (Shanghai) 2005; 37:379-85. [PMID: 15944752 DOI: 10.1111/j.1745-7270.2005.00051.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Our objective was to study the properties of the carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) and the methodology of cell labeling using CFDA-SE fluorescent dye. First, we analyzed the kinetics of CFDA-SE fluorescent dye intensity over time. Second, we determined the optimal concentration of CFDA-SE fluorescent dye for cell labeling. Third, we tested the toxicity of CFDA-SE fluorescent dye on labeled cells. Finally, we determined the optimal staining time of CFDA-SE fluorescent dye for cell labeling. The results show that the optimal concentration of CFDA-SE fluorescent dye for cell labeling varies according to different cell types. CFDA-SE fluorescent dye is non-toxic to cells as the cell death rate caused by CFDA-SE labeling is below 5%. The optimal cell labeling time was determined to be 8 min of incubation with CFDA-SE fluorescent dye. We concluded that the advantages of using CFDA-SE fluorescent dye for cell labeling are as follows: (1) the binding of CFDA-SE fluorescent dye to cells is stable; (2) CFDA-SE fluorescent dye is not toxic and does not modify the viability of labeled cells; and (3) CFDA-SE fluorescent dye is a suitable fluorochrome for cell labeling.
Collapse
Affiliation(s)
- Xiao-Qi Wang
- The Central Laboratory, the First Teaching Hospital of Jilin University, Changchun 130021, China.
| | | | | | | | | |
Collapse
|
49
|
Lee YK, Ho PS, Low CS, Arvilommi H, Salminen S. Permanent colonization by Lactobacillus casei is hindered by the low rate of cell division in mouse gut. Appl Environ Microbiol 2004; 70:670-4. [PMID: 14766540 PMCID: PMC348792 DOI: 10.1128/aem.70.2.670-674.2004] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Long residence times of probiotics in the intestinal tract would prolong their potential beneficial health effects and assist colonization. This study investigated the colonization potential of Lactobacillus casei Shirota in mouse intestine by using 5 (and 6)-carboxyfluorescein diacetate, succinimidyl ester (cFDA-SE) for assessment of doubling times in different parts of the intestine. The amounts of intestinal water overlying the surfaces of the duodenum, jejunum, ileum, and colon in BALB/c mice were 34.4 +/- 2.9, 58.8 +/- 6.8, 21.6 +/- 2.2, and 8.0 +/- 1.0 mg, respectively. Based on the residual concentrations of cFDA-SE-labeled lactobacilli on intestinal mucosal surfaces, the average half times for the wash-out of lactobacilli fed were estimated at 3.98, 1.55, 1.34, and 2.48 days in the duodenum, jejunum, ileum, and colon, respectively. The average doubling times of the lactobacilli, estimated from the residual fluorescent levels of surface-adhered cells, were 4.10, 4.78, 4.56, and 5.59 days in the duodenum, jejunum, ileum, and colon, respectively. It is estimated that the lactobacilli would have to achieve an average doubling time of 1.03 to 2.04 days to colonize the various sections of the mouse intestinal tract more permanently.
Collapse
Affiliation(s)
- Y K Lee
- Department of Microbiology, National University of Singapore, Singapore 117597, Republic of Singapore.
| | | | | | | | | |
Collapse
|
50
|
Luppens SBI, Barbaras B, Breeuwer P, Rombouts FM, Abee T. Selection of fluorescent probes for flow cytometric viability assessment of Listeria monocytogenes exposed to membrane-active and oxidizing disinfectants. J Food Prot 2003; 66:1393-401. [PMID: 12929825 DOI: 10.4315/0362-028x-66.8.1393] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this study was to select fluorescence methods for use as alternatives to plate counting to assess the viability of Listeria monocytogenes cells exposed to benzalkonium chloride (BAC) and hydrogen peroxide, two disinfectants with different mechanisms of action. A further aim of this study was to determine whether growth phase influences fluorescence labeling and whether it is possible to predict whether a probe will be a good viability indicator for cells exposed to a certain disinfectant on the basis of the mechanism of action of the disinfectant and the target of the fluorescent probe. The fluorescence methods used were labeling with 5-cyano-2,3-ditolyl tetrazolium chloride (CTC; dehydrogenase activity), labeling with TOTO-1 iodide (TOTO; membrane-impermeant probe), and assessment of pH gradient maintenance in a low-pH buffer after labeling with the pH-sensitive probe 5-(and 6)-carboxyfluorescein succinimidyl ester (CFSE) (the pH(in) method). Growth phase influenced fluorescent labeling. However, the cutoff value for distinction between viable and nonviable cells was the same for both growth phases. The viability (determined by plate counts) of BAC-exposed cells correlated well with CTC labeling and TOTO exclusion. For both BAC-exposed and hydrogen peroxide-exposed cells, the pH(in) method gave a good qualitative indication of viability, sublethal damage, and cell death. CTC labeling and TOTO exclusion did not correlate with the viability of hydrogen peroxide-exposed cells. Our results demonstrate that even if the mechanism of action of a disinfectant is known, in some cases it is still difficult to predict whether a certain fluorescent probe is suitable for viability assessment. Thus, the proper selection of fluorescent probes for the assessment of the efficacy of antimicrobial agents is essential.
Collapse
Affiliation(s)
- S B I Luppens
- Food Hygiene and Microbiology Group, Department of Agrotechnology and Food Sciences, Wageningen University and Research Center, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
| | | | | | | | | |
Collapse
|