1
|
Xu S, Liu Z, Ren P, Liu Y, Xiao F, Li W. BmfR, a novel GntR family regulator, regulates biofilm formation in marine-derived, Bacillus methylotrophicus B-9987. Microbiol Res 2024; 287:127859. [PMID: 39098095 DOI: 10.1016/j.micres.2024.127859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 07/21/2024] [Accepted: 07/24/2024] [Indexed: 08/06/2024]
Abstract
Biofilms are common living states for microorganisms, allowing them to adapt to environmental changes. Numerous Bacillus strains can form complex biofilms that play crucial roles in biocontrol processes. However, our current understanding of the molecular mechanisms of biofilm formation in Bacillus is mainly based on studies of Bacillus subtilis. Knowledge regarding the biofilm formation of other Bacillus species remains limited. In this study, we identified a novel transcriptional regulator, BmfR, belonging to the GntR family, that regulates biofilm formation in marine-derived Bacillus methylotrophicus B-9987. We demonstrated that BmfR induces biofilm formation by activating the extracellular polysaccharide structural genes epsA-O and negatively regulating the matrix gene repressor, SinR; of note it positively affects the expression of the master regulator of sporulation, Spo0A. Furthermore, database mining for BmfR homologs has revealed their widespread distribution among many bacterial species, mainly Firmicutes and Proteobacteria. This study advances our understanding of the biofilm regulatory network of Bacillus strains, and provides a new target for exploiting and manipulating biofilm formation.
Collapse
Affiliation(s)
- Shanshan Xu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Zengzhi Liu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Pengfei Ren
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Yang Liu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Fei Xiao
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Wenli Li
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shannxi 712100, China.
| |
Collapse
|
2
|
Ren F, Chen Y, Yang S, Zhang Y, Liu Y, Ma Y, Wang Y, Liu Y, Dong Q, Lu D. Characterization of emetic Bacillus cereus biofilm formation and cereulide production in biofilm. Food Res Int 2024; 192:114834. [PMID: 39147521 DOI: 10.1016/j.foodres.2024.114834] [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: 04/14/2024] [Revised: 07/21/2024] [Accepted: 07/21/2024] [Indexed: 08/17/2024]
Abstract
Bacillus cereus is a well-known foodborne pathogen that can cause human diseases, including vomiting caused by emetic toxin, cereulide, requiring 105-108 cells per gram to cause the disease. The bacterial cells may be eliminated during processing, but cereulide can survive in most processing techniques due to its resistance to high temperatures, extreme pH and proteolytic enzymes. Herein, we reported dynamic processes of biofilm formation of four different types and cereulide production within the biofilm. Confocal laser scanning microscopy (CLSM) images revealed that biofilms of the four different types reach each stage at different time points. Among the extracellular polymeric substances (EPS) components of the four biofilms formed by the emetic B. cereus F4810/72 strain, proteins account for the majority. In addition, there are significant differences (p < 0.05) in the EPS components at the same stage among biofilms of different types. The time point at which cereulide was first detected in the four types of biofilms was 24 h. In the biofilm of B. cereus formed in ultra-high-temperature (UHT) milk, the first peak of cereulide appeared at 72 h. The cereulide content of the biofilms formed in BHI was mostly higher than that of the biofilms formed in UHT milk. This study contributes to a better understanding of food safety issues in the industry caused by biofilm and cereulide toxin produced by B. cereus.
Collapse
Affiliation(s)
- Fanchong Ren
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Yuhang Chen
- Shanghai Center for Disease Control and Prevention, Shanghai 200336, China.
| | - Shuo Yang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Yinan Zhang
- Key Laboratory of Milk and Dairy Products Detection and Monitoring Technology for State Market Regulation, Shanghai Institute of Quality Inspection and Technical Research, Shanghai 200233, China.
| | - Yangtai Liu
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Yue Ma
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Yating Wang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Yang Liu
- Key Laboratory of Milk and Dairy Products Detection and Monitoring Technology for State Market Regulation, Shanghai Institute of Quality Inspection and Technical Research, Shanghai 200233, China.
| | - Qingli Dong
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Dasheng Lu
- Shanghai Center for Disease Control and Prevention, Shanghai 200336, China.
| |
Collapse
|
3
|
Byun KH, Kang M, Seon Koo M, Lim MC, Sik Ok G, Jung Kim H. Potential risk of biofilm-forming Bacillus cereus group in fresh-cut lettuce production chain. Food Res Int 2024; 191:114692. [PMID: 39059950 DOI: 10.1016/j.foodres.2024.114692] [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: 01/17/2024] [Revised: 06/24/2024] [Accepted: 06/26/2024] [Indexed: 07/28/2024]
Abstract
Bacillus cereus and Bacillus thuringiensis, which belong to the B. cereus group, are widely distributed in nature and can cause food poisoning symptoms. In this study, we collected 131 isolates belonging to the B. cereus group, comprising 124B. cereus and seven B. thuringiensis isolates, from fresh-cut lettuce production chain and investigated their potential risk by analyzing genotypic (enterotoxin and emetic toxin gene profiles) and phenotypic (antibiotic susceptibility, sporulation, and biofilm formation) characteristics. Enterotoxin genes were present only in B. cereus, whereas the emetic toxin gene was not detected in any of the B. cereus isolates. All isolates were susceptible to vancomycin, which is a last resort for treating B. cereus group infection symptoms, but generally resistant to β-lactam antimicrobials, and had the ability to form spores (at an average sporulation rate of 24.6 %) and biofilms at 30 °C. Isolates that formed strong biofilms at 30 °C had a superior possibility of forming a dense biofilm by proliferating at 10 °C compared to other isolates. Additionally, confocal laser scanning microscopy (CLSM) images revealed a notable presence of spores within the submerged biofilm formed at 10 °C, and the strengthened attachment of biofilm inner cells to the substrate was further revealed through biofilm structure parameters analysis. Collectively, our study revealed the prevalence and contamination levels of B. cereus and B. thuringiensis at fresh-cut lettuce production chain and investigated their genotypic and phenotypic characteristics, aiming to provide valuable insights for the development of potential risk management strategies to ensure food safety, especially along the cold chain.
Collapse
Affiliation(s)
- Kye-Hwan Byun
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Technology Innovation Research Division, Hygienic Safety and Materials Research Group, World Institute of Kimchi, Gwangju 61755, Republic of Korea
| | - Miseon Kang
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Department of Food Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Min Seon Koo
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Department of Food Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Min-Cheol Lim
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Department of Food Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Gyeong Sik Ok
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea
| | - Hyun Jung Kim
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Department of Food Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea.
| |
Collapse
|
4
|
Sleutel M, Zegeye ED, Llarena AK, Pradhan B, Fislage M, O'Sullivan K, Van Gerven N, Aspholm M, Remaut H. Helical ultrastructure of the L-ENA spore aggregation factor of a Bacillus paranthracis foodborne outbreak strain. Nat Commun 2024; 15:7514. [PMID: 39209852 PMCID: PMC11362473 DOI: 10.1038/s41467-024-51804-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 08/16/2024] [Indexed: 09/04/2024] Open
Abstract
In pathogenic Bacillota, spores can form an infectious particle and can take up a central role in the environmental persistence and dissemination of disease. A poorly understood aspect of spore-mediated infection is the fibrous structures or 'endospore appendages' (ENAs) that have been seen to decorate the spores of pathogenic Bacilli and Clostridia. Current methodological approaches are opening a window on these long enigmatic structures. Using cryoID, Alphafold modelling and genetic approaches we identify a sub-class of robust ENAs in a Bacillus paranthracis foodborne outbreak strain. We demonstrate that L-ENA are encoded by a rare three-gene cluster (ena3) that contains all components for the self-assembly of ladder-like protein nanofibers of stacked heptameric rings, their anchoring to the exosporium, and their termination in a trimeric 'ruffle' made of a complement C1Q-like BclA paralogue. The role of ENA fibers in spore-spore interaction and the distribution of L-ENA operon as mobile genetic elements in B. cereus s.l. strains suggest that L-ENA fibers may increase the survival, spread and virulence of these strains.
Collapse
Affiliation(s)
- Mike Sleutel
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Brussels, Belgium.
| | - Ephrem Debebe Zegeye
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Ann-Katrin Llarena
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Brajabandhu Pradhan
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Brussels, Belgium
| | - Marcus Fislage
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Brussels, Belgium
| | - Kristin O'Sullivan
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Nani Van Gerven
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Brussels, Belgium
| | - Marina Aspholm
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Han Remaut
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Brussels, Belgium.
| |
Collapse
|
5
|
Mazzantini D, Gherardini G, Rossi V, Celandroni F, Calvigioni M, Panattoni A, Massimino M, Lupetti A, Ghelardi E. Dissecting the role of the MS-ring protein FliF in Bacillus cereus flagella-related functions. Mol Microbiol 2024; 122:255-270. [PMID: 39030901 DOI: 10.1111/mmi.15299] [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: 12/13/2023] [Revised: 07/05/2024] [Accepted: 07/06/2024] [Indexed: 07/22/2024]
Abstract
The flagellar MS-ring, uniquely constituted by FliF, is essential for flagellar biogenesis and functionality in several bacteria. The aim of this study was to dissect the role of FliF in the Gram-positive and peritrichously flagellated Bacillus cereus. We demonstrate that fliF forms an operon with the upstream gene fliE. In silico analysis of B. cereus ATCC 14579 FliF identifies functional domains and amino acid residues that are essential for protein functioning. The analysis of a ΔfliF mutant of B. cereus, constructed in this study using an in frame markerless gene replacement method, reveals that the mutant is unexpectedly able to assemble flagella, although in reduced amounts compared to the parental strain. Nevertheless, motility is completely abolished by fliF deletion. FliF deprivation causes the production of submerged biofilms and affects the ability of B. cereus to adhere to gastrointestinal mucins. We additionally show that the fliF deletion does not compromise the secretion of the three components of hemolysin BL, a toxin secreted through the flagellar type III secretion system. Overall, our findings highlight the important role of B. cereus FliF in flagella-related functions, being the protein required for complete flagellation, motility, mucin adhesion, and pellicle biofilms.
Collapse
Affiliation(s)
- Diletta Mazzantini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Guendalina Gherardini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Virginia Rossi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Francesco Celandroni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Marco Calvigioni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Adelaide Panattoni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Mariacristina Massimino
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Antonella Lupetti
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Emilia Ghelardi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- Research Center Nutraceuticals and Food for Health-Nutrafood, University of Pisa, Pisa, Italy
| |
Collapse
|
6
|
Lee C, Park YS. Probiotic and immunostimulating effects of live and heat-killed Pediococcus pentosaceus TAP041. Food Sci Biotechnol 2024; 33:2189-2200. [PMID: 39130656 PMCID: PMC11315844 DOI: 10.1007/s10068-024-01530-2] [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: 11/16/2023] [Revised: 01/10/2024] [Accepted: 01/15/2024] [Indexed: 08/13/2024] Open
Abstract
The selected strain, TAP041, showing an excellent ability to reduce the glyoxal and methylglyoxal levels, was identified by 16S rRNA gene-based phylogenetic analysis as Pediococcus pentosaceus. It demonstrated probiotic properties, including acid, bile salt, pancreatin, lysozyme tolerance, gut adhesion, and auto/coaggregation. In RAW264.7 macrophages, both live and heat-killed strains induced nitric oxide production and activated inducible nitric oxide synthase. RAW264.7 treated with P. pentosaceus TAP041 increased the expression level of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and cyclooxygenase-2, and regulated the expression of c-Jun amino-terminal kinase, p38, and extracellular signal-regulated kinase. These findings suggest that both live and heat-killed P. pentosaceus TAP041 can be used as potential immunostimulatory agents in functional food additives. Supplementary Information The online version contains supplementary material available at 10.1007/s10068-024-01530-2.
Collapse
Affiliation(s)
- Chaeeun Lee
- Department of Food Science and Biotechnology, Gachon University, Seongnam, 13120 Republic of Korea
| | - Young-Seo Park
- Department of Food Science and Biotechnology, Gachon University, Seongnam, 13120 Republic of Korea
| |
Collapse
|
7
|
Xiang SL, Xu KZ, Yin LJ, Jia AQ. An Investigation of Quorum Sensing Inhibitors against Bacillus cereus in The Endophytic Fungus Pithomyces sacchari of the Laurencia sp. Mar Drugs 2024; 22:161. [PMID: 38667778 PMCID: PMC11051030 DOI: 10.3390/md22040161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/28/2024] Open
Abstract
Bacillus cereus, a common food-borne pathogen, forms biofilms and generates virulence factors through a quorum sensing (QS) mechanism. In this study, six compounds (dankasterone A, demethylincisterol A3, zinnimidine, cyclo-(L-Val-L-Pro), cyclo-(L-Ile-L-Pro), and cyclo-(L-Leu-L-Pro)) were isolated from the endophytic fungus Pithomyces sacchari of the Laurencia sp. in the South China Sea. Among them, demethylincisterol A3, a sterol derivative, exhibited strong QS inhibitory activity against B. cereus. The QS inhibitory activity of demethylincisterol A3 was evaluated through experiments. The minimum inhibitory concentration (MIC) of demethylincisterol A3 against B. cereus was 6.25 μg/mL. At sub-MIC concentrations, it significantly decreased biofilm formation, hindered mobility, and diminished the production of protease and hemolysin activity. Moreover, RT-qPCR results demonstrated that demethylincisterol A3 markedly inhibited the expression of QS-related genes (plcR and papR) in B. cereus. The exposure to demethylincisterol A3 resulted in the downregulation of genes (comER, tasA, rpoN, sinR, codY, nheA, hblD, and cytK) associated with biofilm formation, mobility, and virulence factors. Hence, demethylincisterol A3 is a potentially effective compound in the pipeline of innovative antimicrobial therapies.
Collapse
Affiliation(s)
| | | | | | - Ai-Qun Jia
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China
| |
Collapse
|
8
|
Sun Y, Shuai W, Nie L, Li X, Jiang L. Investigating the Role of OrbF in Biofilm Biosynthesis and Regulation of Biofilm-Associated Genes in Bacillus cereus BC1. Foods 2024; 13:638. [PMID: 38472751 DOI: 10.3390/foods13050638] [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: 12/12/2023] [Revised: 01/11/2024] [Accepted: 01/22/2024] [Indexed: 03/14/2024] Open
Abstract
Bacillus cereus (B. cereus), a prevalent foodborne pathogen, constitutes a substantial risk to food safety due to its pronounced resilience under adverse environmental conditions such as elevated temperatures and ultraviolet radiation. This resilience can be attributed to its capacity for biofilm synthesis and sustained high viability. Our research aimed to elucidate the mechanisms governing biofilm biosynthesis in B. cereus. To this end, we constructed a 5088-mutant library of the B. cereus strain BC1 utilizing the transposon TnYLB-1. Systematic screening of this library yielded mutants exhibiting diminished biofilm formation capabilities. Twenty-four genes associated with the biofilm synthesis were identified by reverse PCR in these mutants, notably revealing a significant reduction in biofilm synthesis upon disruption of the orbF gene in B. cereus BC1. Comparative analysis between the wild type and orbF-deficient BC1 strains (BC1ΔorbF) indicated a marked downregulation (decreased by 11.7% to 96.7%) in the expression of genes implicated in biofilm formation, flagellar assembly, and bacterial chemotaxis in the BC1ΔorbF. Electrophoretic mobility shift assay (EMSA) further corroborated the role of OrbF, demonstrating its binding to the promoter region of the biofilm gene cluster, subsequently leading to the suppression of transcriptional activity of biofilm-associated genes in B. cereus BC1. Our findings underscore the pivotal role of orbF in biofilm biosynthesis in B. cereus, highlighting its potential as a target for strategies aimed at mitigating biofilm formation in this pathogen.
Collapse
Affiliation(s)
- Yang Sun
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Wenjing Shuai
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Lanmengya Nie
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Xiangfei Li
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic & Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China
| | - Ling Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| |
Collapse
|
9
|
Szymańska S, Deja-Sikora E, Sikora M, Niedojadło K, Mazur J, Hrynkiewicz K. Colonization of Raphanus sativus by human pathogenic microorganisms. Front Microbiol 2024; 15:1296372. [PMID: 38426059 PMCID: PMC10902717 DOI: 10.3389/fmicb.2024.1296372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 01/15/2024] [Indexed: 03/02/2024] Open
Abstract
Contamination of vegetables with human pathogenic microorganisms (HPMOs) is considered one of the most important problems in the food industry, as current nutritional guidelines include increased consumption of raw or minimally processed organic vegetables due to healthy lifestyle promotion. Vegetables are known to be potential vehicles for HPMOs and sources of disease outbreaks. In this study, we tested the susceptibility of radish (Raphanus sativus) to colonization by different HPMOs, including Escherichia coli PCM 2561, Salmonella enterica subsp. enterica PCM 2565, Listeria monocytogenes PCM 2191 and Bacillus cereus PCM 1948. We hypothesized that host plant roots containing bactericidal compounds are less prone to HPMO colonization than shoots and leaves. We also determined the effect of selected pathogens on radish growth to check host plant-microbe interactions. We found that one-week-old radish is susceptible to colonization by selected HPMOs, as the presence of the tested HPMOs was demonstrated in all organs of R. sativus. The differences were noticed 2 weeks after inoculation because B. cereus was most abundant in roots (log10 CFU - 2.54), S. enterica was observed exclusively in stems (log10 CFU - 3.15), and L. monocytogenes and E. coli were most abundant in leaves (log10 CFU - 4.80 and 3.23, respectively). The results suggest that E. coli and L. monocytogenes show a higher ability to colonize and move across the plant than B. cereus and S. enterica. Based on fluorescence in situ hybridization (FISH) and confocal laser scanning microscopy (CLSM) approach HPMOs were detected in extracellular matrix and in some individual cells of all analyzed organs. The presence of pathogens adversely affected the growth parameters of one-week-old R. sativus, especially leaf and stem fresh weight (decreased by 47-66 and 17-57%, respectively). In two-week-old plants, no reduction in plant biomass development was noted. This observation may result from plant adaptation to biotic stress caused by the presence of HPMOs, but confirmation of this assumption is needed. Among the investigated HPMOs, L. monocytogenes turned out to be the pathogen that most intensively colonized the aboveground part of R. sativus and at the same time negatively affected the largest number of radish growth parameters.
Collapse
Affiliation(s)
- Sonia Szymańska
- Department of Microbiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Toruń, Poland
| | - Edyta Deja-Sikora
- Department of Microbiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Toruń, Poland
| | - Marcin Sikora
- Center for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Toruń, Poland
| | - Katarzyna Niedojadło
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Toruń, Poland
| | - Justyna Mazur
- Center for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Toruń, Poland
| | - Katarzyna Hrynkiewicz
- Department of Microbiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Toruń, Poland
| |
Collapse
|
10
|
Zhu S, Xie J, Yang J, Hou X, He L, Zhang Z. Seed-Borne Bacterial Diversity of Fescue ( Festuca ovina L.) and Properties Study. Microorganisms 2024; 12:329. [PMID: 38399732 PMCID: PMC10892014 DOI: 10.3390/microorganisms12020329] [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: 01/08/2024] [Revised: 01/21/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Rich endophytic bacterial communities exist in fescue (Festuca ovina L.) and play an important role in fescue growth, cold tolerance, drought tolerance and antibiotic tolerance. To screen for probiotics carried by fescue seeds, seven varieties were collected from three different regions of China for isolation by the milled seed method and analyzed for diversity and motility, biofilm and antibiotic resistance. A total of 91 bacterial isolates were obtained, and based on morphological characteristics, 36 representative dominant strains were selected for 16S rDNA sequencing analysis. The results showed that the 36 bacterial strains belonged to four phyla and nine genera. The Firmicutes was the dominant phylum, and Bacillus, Paenibacillus and Pseudomonas were the dominant genera. Most of the strains had motility (80%) and were biofilm-forming (91.7%). In this study, 15 strains were capable of Indole-3-acetic acid (IAA) production, 24 strains were capable of nitrogen fixation, and some strains possessed amylase and protease activities, suggesting their potential for growth promotion. Determination of the minimum inhibitory concentration (MIC) against the bacteria showed that the strains were not resistant to tetracycline and oxytetracycline. Pantoea (QY6, LH4, MS2) and Curtobacterium (YY4) showed resistance to five antibiotics (ampicillin, kanamycin, erythromycin, sulfadiazine and rifampicin). Using Pearson correlation analysis, a significant correlation was found between motility and biofilm, and between biofilm and sulfadiazine. In this study, we screened two strains of Pantoea (QY6, LH4) with excellent growth-promoting ability as well as broad-spectrum antibiotic resistance. which provided new perspectives for subsequent studies on the strong ecological adaptations of fescue, and mycorrhizal resources for endophytic bacteria and plant interactions.
Collapse
Affiliation(s)
| | | | | | | | | | - Zhenfen Zhang
- Key Laboratory of Grassland Ecosystem, Ministry of Education, Pratacultural College, Gansu Agricultural University, Lanzhou 730070, China; (S.Z.); (J.X.); (J.Y.); (X.H.); (L.H.)
| |
Collapse
|
11
|
Zhou Q, Li G, Cui Y, Xiang J, Zhu S, Li S, Huang J, Wang Y, Liu Y, Zhou L. Genomic characterization of Bacillus cereus isolated from food poisoning cases revealed the mechanism of toxin production. Front Microbiol 2024; 14:1238799. [PMID: 38282728 PMCID: PMC10822677 DOI: 10.3389/fmicb.2023.1238799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 12/12/2023] [Indexed: 01/30/2024] Open
Abstract
Introduction Bacillus cereus is a ubiquitous opportunistic human pathogen that causes food intoxications worldwide. However, the genomic characteristics and pathogenic mechanisms of B. cereus are still unclear. Methods Here, we isolated and purified nine strains of B. cereus (LY01-LY09) that caused vomiting, diarrhea and other symptoms from four foodborne outbreaks happened in Guizhou Province in southwest China from June to September 2021. After colony observation, Gram staining, microscopic examination and biochemical test, they were identified as B. cereus. The genomic characteristics, phylogenetic relationships and virulence factors of the isolated strains were analyzed at the genome level. Genome sequencing, comparative genomic analysis, secondary metabolite analysis and quantitative PCR were utilized to give a thorough exploration of the strains. Results We obtained the genome maps of LY01-LY09 and found that LY01-LY09 had a complex interspecific relationship with B. anthracis and B. thuringiensis. We also observed a contraction of gene families in LY01-LY09, and the contracted families were mainly associated with prophage, which contributed to the species diversity of B. cereus. The Hsp20 gene family underwent a rapid evolution in LY01-LY09, which facilitated the adaptation of the strains to adverse environmental conditions. Moreover, the LY01-LY09 strains exhibited a higher copy number in the non-ribosomal polypeptide synthetase (NRPS) genes and carried the complete cereulide synthetase (ces) gene cluster sequences. Considering that the NRPS system is a classical regulatory mechanism for emetic toxin synthesis, we hypothesized that LY01-LY09 could synthesize emetic toxins through the regulation of ces gene clusters by the NRPS system. Discussion These findings are important for further investigation into the evolutionary relationship between B. cereus and their related species, as well as the underlying mechanisms governing the synthesis and secretion of bacterial toxins.
Collapse
Affiliation(s)
- Qian Zhou
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Guanqiao Li
- College of Bioinformatics, Chongqing University of Post and Telecommunications, Chongqing, China
| | - Yinshan Cui
- Yunnan Pulis Biotechnology Co., Ltd., Kunming, Yunnan, China
| | - Jingshu Xiang
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Shu Zhu
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Shijun Li
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Jingyu Huang
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Yafang Wang
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Ying Liu
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Li Zhou
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| |
Collapse
|
12
|
Vittoria M, Saggese A, Di Gregorio Barletta G, Castaldi S, Isticato R, Baccigalupi L, Ricca E. Sporulation efficiency and spore quality in a human intestinal isolate of Bacillus cereus. Res Microbiol 2023; 174:104030. [PMID: 36738815 DOI: 10.1016/j.resmic.2023.104030] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/18/2023] [Accepted: 01/20/2023] [Indexed: 02/05/2023]
Abstract
Bacteria classified as Bacillus cereus sensu stricto cause two different type of gastrointestinal diseases associated with food poisoning. Outbreaks of this opportunistic pathogen are generally due to the resistance of its spores to heat, pH and desiccation that makes hard their complete inactivation from food products. B. cereus is commonly isolated from a variety of environments, including intestinal samples of infected and healthy people. We report the genomic and physiological characterization of MV19, a human intestinal strain closely related (ANI value of 98.81%) to the reference strain B. cereus ATCC 14579. MV19 cells were able to grow in a range of temperatures between 20 and 44 °C. At the optimal temperature the sporulation process was rapidly induced and mature spores efficiently released, however these appeared structurally and morphologically defective. At the sub-optimal growth temperature of 25 °C sporulation was slow and less efficient but a high total number of fully functional spores was produced. These results indicate that the reduced rapidity and efficiency of sporulation at 25 °C are compensated by a high quality and quantity of released spores, suggesting the relevance of different performances at different growth conditions for the adaptation of this bacterium to diverse environmental niches.
Collapse
Affiliation(s)
- Maria Vittoria
- Department of Biology, Federico II University of Naples, Italy
| | - Anella Saggese
- Department of Biology, Federico II University of Naples, Italy
| | | | | | | | - Loredana Baccigalupi
- Department of Molecular Medicine and Medical Biotechnology, Federico II University of Naples, Italy
| | - Ezio Ricca
- Department of Biology, Federico II University of Naples, Italy.
| |
Collapse
|
13
|
Huijboom L, Tempelaars M, Fan M, Zhu Y, Boeren S, van der Linden E, Abee T. l-tyrosine modulates biofilm formation of Bacillus cereus ATCC 14579. Res Microbiol 2023; 174:104072. [PMID: 37080258 DOI: 10.1016/j.resmic.2023.104072] [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: 10/22/2022] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 04/22/2023]
Abstract
Bacillus cereus is a food-borne pathogen capable of producing biofilms. Following analysis of biofilm formation by B. cereus ATCC 14579 transposon mutants in defined medium (DM), a deletion mutant of bc2939 (Δbc2939) was constructed that showed decreased crystal violet biofilm staining and biofilm cell counts. In addition, Δbc2939 also produced smaller colony biofilms with lower cell counts and loss of wrinkly morphology. The bc2939 gene encodes for Prephenate dehydrogenase, which converts Prephenate to 4-Hydroxy-phenylpyruvate (4-HPPA) in the l-tyrosine branch of the Shikimate pathway. While growth of the mutant and WT in DM was similar, addition of l-tyrosine was required to restore WT-like (colony) biofilm formation. Comparative proteomics showed reduced expression of Tyrosine-protein kinase/phosphatase regulators and extracellular polysaccharide cluster 1 (EPS1) proteins, aerobic electron transfer chain cytochrome aa3/d quinol oxidases, and iso-chorismate synthase involved in menaquinone synthesis in DM grown mutant biofilm cells, while multiple oxidative stress-related catalases and superoxide dismutases were upregulated. Performance in shaking cultures showed a 100-fold lower concentration of menaquinone-7 and reduction in cell counts of DM grown Δbc2939 indicating increased oxygen sensitivity. Combining all results, points to an important role of Tyrosine-modulated EPS1 production and menaquinone-dependent aerobic respiration in B. cereus ATCC 14579 (colony) biofilm formation.
Collapse
Affiliation(s)
- Linda Huijboom
- Food Microbiology, Wageningen University & Research, Bornse Weilanden 9, 6708, WG, Wageningen, the Netherlands.
| | - Marcel Tempelaars
- Food Microbiology, Wageningen University & Research, Bornse Weilanden 9, 6708, WG, Wageningen, the Netherlands.
| | - Mingzhen Fan
- Food Microbiology, Wageningen University & Research, Bornse Weilanden 9, 6708, WG, Wageningen, the Netherlands.
| | - Yourong Zhu
- Food Microbiology, Wageningen University & Research, Bornse Weilanden 9, 6708, WG, Wageningen, the Netherlands.
| | - Sjef Boeren
- Laboratory of Biochemistry, Wageningen University & Research, Stippeneng 4, Wageningen, 6708, WE, the Netherlands.
| | - Erik van der Linden
- Laboratory of Physics and Physical Chemistry of Foods, Wageningen University & Research, Bornse Weilanden 9, 6708, WG, Wageningen, the Netherlands.
| | - Tjakko Abee
- Food Microbiology, Wageningen University & Research, Bornse Weilanden 9, 6708, WG, Wageningen, the Netherlands.
| |
Collapse
|
14
|
Nilsson DPG, Jonsmoen UL, Malyshev D, Öberg R, Wiklund K, Andersson M. Physico-chemical characterization of single bacteria and spores using optical tweezers. Res Microbiol 2023; 174:104060. [PMID: 37068697 DOI: 10.1016/j.resmic.2023.104060] [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: 10/21/2022] [Revised: 03/23/2023] [Accepted: 04/05/2023] [Indexed: 04/19/2023]
Abstract
Spore-forming pathogenic bacteria are adapted for adhering to surfaces, and their endospores can tolerate strong chemicals making decontamination difficult. Understanding the physico-chemical properties of bacteria and spores is therefore essential in developing antiadhesive surfaces and disinfection techniques. However, measuring physico-chemical properties in bulk does not show the heterogeneity between cells. Characterizing bacteria on a single-cell level can thereby provide mechanistic clues usually hidden in bulk measurements. This paper shows how optical tweezers can be applied to characterize single bacteria and spores, and how physico-chemical properties related to adhesion, fluid dynamics, biochemistry, and metabolic activity can be assessed.
Collapse
Affiliation(s)
| | - Unni Lise Jonsmoen
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Norway.
| | - Dmitry Malyshev
- Department of Physics, Umeå University, Västerbotten 901 87 Sweden.
| | - Rasmus Öberg
- Department of Physics, Umeå University, Västerbotten 901 87 Sweden.
| | - Krister Wiklund
- Department of Physics, Umeå University, Västerbotten 901 87 Sweden.
| | - Magnus Andersson
- Department of Physics, Umeå University, Västerbotten 901 87 Sweden; Umeå Center for Microbial Research (UCMR), 901 87 Sweden.
| |
Collapse
|
15
|
Kulkova I, Dobrzyński J, Kowalczyk P, Bełżecki G, Kramkowski K. Plant Growth Promotion Using Bacillus cereus. Int J Mol Sci 2023; 24:ijms24119759. [PMID: 37298706 DOI: 10.3390/ijms24119759] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 05/25/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023] Open
Abstract
Plant growth-promoting bacteria (PGPB) appear to be a sensible competitor to conventional fertilization, including mineral fertilizers and chemical plant protection products. Undoubtedly, one of the most interesting bacteria exhibiting plant-stimulating traits is, more widely known as a pathogen, Bacillus cereus. To date, several environmentally safe strains of B. cereus have been isolated and described, including B. cereus WSE01, MEN8, YL6, SA1, ALT1, ERBP, GGBSTD1, AK1, AR156, C1L, and T4S. These strains have been studied under growth chamber, greenhouse, and field conditions and have shown many significant traits, including indole-3-acetic acid (IAA) and aminocyclopropane-1-carboxylic acid (ACC) deaminase production or phosphate solubilization, which allows direct plant growth promotion. It includes an increase in biometrics traits, chemical element content (e.g., N, P, and K), and biologically active substances content or activity, e.g., antioxidant enzymes and total soluble sugar. Hence, B. cereus has supported the growth of plant species such as soybean, maize, rice, and wheat. Importantly, some B. cereus strains can also promote plant growth under abiotic stresses, including drought, salinity, and heavy metal pollution. In addition, B. cereus strains produced extracellular enzymes and antibiotic lipopeptides or triggered induced systemic resistance, which allows indirect stimulation of plant growth. As far as biocontrol is concerned, these PGPB can suppress the development of agriculturally important phytopathogens, including bacterial phytopathogens (e.g., Pseudomonas syringae, Pectobacterium carotovorum, and Ralstonia solanacearum), fungal phytopathogens (e.g., Fusarium oxysporum, Botrytis cinerea, and Rhizoctonia solani), and other phytopathogenic organisms (e.g., Meloidogyne incognita (Nematoda) and Plasmodiophora brassicae (Protozoa)). In conclusion, it should be noted that there are still few studies on the effectiveness of B. cereus under field conditions, particularly, there is a lack of comprehensive analyses comparing the PGP effects of B. cereus and mineral fertilizers, which should be reduced in favor of decreasing the use of mineral fertilizers. It is also worth mentioning that there are still very few studies on the impact of B. cereus on the indigenous microbiota and its persistence after application to soil. Further studies would help to understand the interactions between B. cereus and indigenous microbiota, subsequently contributing to increasing its effectiveness in promoting plant growth.
Collapse
Affiliation(s)
- Iryna Kulkova
- Institute of Technology and Life Sciences-National Research Institute, Falenty, 3 Hrabska Avenue, 05-090 Raszyn, Poland
| | - Jakub Dobrzyński
- Institute of Technology and Life Sciences-National Research Institute, Falenty, 3 Hrabska Avenue, 05-090 Raszyn, Poland
| | - Paweł Kowalczyk
- Department of Animal Nutrition, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3 Str., 05-110 Jabłonna, Poland
| | - Grzegorz Bełżecki
- Department of Animal Nutrition, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3 Str., 05-110 Jabłonna, Poland
| | - Karol Kramkowski
- Department of Physical Chemistry, Medical University of Białystok, Kilińskiego 1 Str., 15-089 Białystok, Poland
| |
Collapse
|
16
|
Toukabri H, Lereclus D, Slamti L. A Sporulation-Independent Way of Life for Bacillus thuringiensis in the Late Stages of an Infection. mBio 2023:e0037123. [PMID: 37129506 DOI: 10.1128/mbio.00371-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
The formation of endospores has been considered the unique survival and transmission mode of sporulating Firmicutes due to the exceptional resistance and persistence of this bacterial form. However, nonsporulated bacteria (Spo-) were reported at the early stages following the death of a host infected with Bacillus thuringiensis, an entomopathogenic sporulating bacterium. Here, we investigated the characteristics of the bacterial population in the late stages of an infection in the B. thuringiensis/Galleria mellonella infection model. Using fluorescent reporters and molecular markers coupled to flow cytometry, we demonstrated that the Spo- cells persist and constitute about half of the population 2 weeks post-infection (p.i.). Protein synthesis and growth recovery assays indicated that they are in a metabolically slowed-down state. These bacteria were extremely resistant to the insect cadaver environment, which did not support growth of in vitro-grown vegetative cells and spores. A transcriptomic analysis of this subpopulation at 7 days p.i. revealed a signature profile of this state, and the expression analysis of individual genes at the cell level showed that more bacteria mount an oxidative stress response as their survival time increases, in agreement with the increase of the free radical level in the host cadaver and in the number of reactive oxygen species (ROS)-producing bacteria. Altogether, these data show for the first time that nonsporulated bacteria are able to survive for a prolonged period of time in the context of an infection and indicate that they engage in a profound adaptation process that leads to their persistence in the host cadaver. IMPORTANCE Bacillus thuringiensis is an entomopathogenic bacterium widely used as a biopesticide. It belongs to the Bacillus cereus group, comprising the foodborne pathogen B. cereus sensu stricto and the anthrax agent Bacillus anthracis. Like other Firmicutes when they encounter harsh conditions, these Gram-positive bacteria can form dormant cells called spores. Due to its highly resistant nature, the spore was considered the unique mode of long-term survival, eclipsing any other form of persistence. Breaking this paradigm, we observed that B. thuringiensis was able to persist in its host cadaver in a nonsporulated form for at least 14 days. Our results show that these bacteria survived in the cadaver environment, which proved hostile for actively growing bacteria by engaging in a profound adaptation process. Studying this facet of the life cycle of a sporulating bacterium provides new fundamental knowledge and might lead to the development of strategies to combat sporulating pathogenic species.
Collapse
Affiliation(s)
- Hasna Toukabri
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Didier Lereclus
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Leyla Slamti
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| |
Collapse
|
17
|
Acar Eser N, Ceylanoglu KS, Malkoc Sen E, Evren E. The influence of microorganisms on early relapses after external dacryocystorhinostomy. Int Ophthalmol 2023:10.1007/s10792-023-02709-y. [PMID: 37081132 DOI: 10.1007/s10792-023-02709-y] [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: 12/13/2022] [Accepted: 04/09/2023] [Indexed: 04/22/2023]
Abstract
PURPOSE Understanding the influence of microorganisms in patients with acquired nasolacrimal duct obstruction (NLDO) and investigating their effect on recurrence after external dacryocystorhinostomy (DCR). METHODS This prospective study included 50 patients. Evaluations were made before, on the first postoperative day and monthly after DCR. Nasolacrimal silicon tubes (NST) were removed after three months. Before the DCR, swab samples were taken from both hands and lower conjunctival fornices and from the lacrimal sac during the first DCR and from the relapsed cases during the second DCR. RESULTS Growth was observed in 90 (45%) cultures out of 200 and a total of 23 different strains were identified altogether. Staphylococcus aureus (40%) and Streptococcus pneumoniae (28%) were dominantly isolated which were all resistant to penicillin, tetracycline and erythromycin. Lacrimal syringing (LS) was successful in patients (100%) on the first postoperative day. After three months, before NST removal, purulent discharge from the punctum was observed in five patients, and blockage was detected by LS. S. pneumoniae was isolated from all five patients' obstructed side conjunctival cultures. Additionally, from their lacrimal sac, S. pneumoniae (4 patients), Capnocytophaga gingivalis, and Candida spp. (1 patient) strains were isolated. S pneumoniae was isolated in four out of five patients from the ipsilateral conjunctival and lacrimal sac cultures which obtained from the subsequent DCR. CONCLUSION Our results showed that S. pneumoniae was an isolated and persistent strain in cases with early recurrence even after a successful DCR.
Collapse
Affiliation(s)
- Nazan Acar Eser
- Department of Ophthalmology, University of Health Science, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
| | - Kubra Serbest Ceylanoglu
- Department of Ophthalmology, University of Health Science, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Emine Malkoc Sen
- Department of Ophthalmology, University of Health Science, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Ebru Evren
- Ankara University School of Medicine Department of Medical Microbiology and İbn-I Sina Hospital Central Microbiology Laboratory, Ankara, Turkey
| |
Collapse
|
18
|
Exploring Possible Ways to Enhance the Potential and Use of Natural Products through Nanotechnology in the Battle against Biofilms of Foodborne Bacterial Pathogens. Pathogens 2023; 12:pathogens12020270. [PMID: 36839543 PMCID: PMC9967150 DOI: 10.3390/pathogens12020270] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 02/10/2023] Open
Abstract
Biofilms enable pathogenic bacteria to survive in unfavorable environments. As biofilm-forming pathogens can cause rapid food spoilage and recurrent infections in humans, especially their presence in the food industry is problematic. Using chemical disinfectants in the food industry to prevent biofilm formation raises serious health concerns. Further, the ability of biofilm-forming bacterial pathogens to tolerate disinfection procedures questions the traditional treatment methods. Thus, there is a dire need for alternative treatment options targeting bacterial pathogens, especially biofilms. As clean-label products without carcinogenic and hazardous potential, natural compounds with growth and biofilm-inhibiting and biofilm-eradicating potentials have gained popularity as natural preservatives in the food industry. However, the use of these natural preservatives in the food industry is restricted by their poor availability, stability during food processing and storage. Also there is a lack of standardization, and unattractive organoleptic qualities. Nanotechnology is one way to get around these limitations and as well as the use of underutilized bioactives. The use of nanotechnology has several advantages including traversing the biofilm matrix, targeted drug delivery, controlled release, and enhanced bioavailability, bioactivity, and stability. The nanoparticles used in fabricating or encapsulating natural products are considered as an appealing antibiofilm strategy since the nanoparticles enhance the activity of the natural products against biofilms of foodborne bacterial pathogens. Hence, this literature review is intended to provide a comprehensive analysis of the current methods in nanotechnology used for natural products delivery (biofabrication, encapsulation, and nanoemulsion) and also discuss the different promising strategies employed in the recent and past to enhance the inhibition and eradication of foodborne bacterial biofilms.
Collapse
|
19
|
Electrochemical Control of Biofilm Formation and Approaches to Biofilm Removal. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12136320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review deals with microbial adhesion to metal-based surfaces and the subsequent biofilm formation, showing that both processes are a serious problem in the food industry, where pathogenic microorganisms released from the biofilm structure may pollute food and related material during their production. Biofilm exhibits an increased resistance toward sanitizers and disinfectants, which complicates the removal or inactivation of microorganisms in these products. In the existing traditional techniques and modern approaches for clean-in-place, electrochemical biofilm control offers promising technology, where surface properties or the reactions taking place on the surface are controlled to delay or prevent cell attachment or to remove microbial cells from the surface. In this overview, biofilm characterization, the classification of bacteria-forming biofilms, the influence of environmental conditions for bacterial attachment to material surfaces, and the evaluation of the role of biofilm morphology are described in detail. Health aspects, biofilm control methods in the food industry, and conventional approaches to biofilm removal are included as well, in order to consider the possibilities and limitations of various electrochemical approaches to biofilm control with respect to potential applications in the food industry.
Collapse
|