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Somerton BT, Morgan BL. Comparison of plate counting with flow cytometry, using four different fluorescent dye techniques, for the enumeration of Bacillus cereus in milk. J Microbiol Methods 2024; 223:106978. [PMID: 38936432 DOI: 10.1016/j.mimet.2024.106978] [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: 05/17/2024] [Revised: 06/23/2024] [Accepted: 06/24/2024] [Indexed: 06/29/2024]
Abstract
This study aimed to compare the performance of flow cytometry methods with plate counting for the enumeration of bacteria, using Bacillus cereus as a model organism. It was found that the cFDA-propidium iodide, CellROX™ Green-propidium iodide, and DiOC2 dye techniques had similar accuracy to plate counting, while the SYTO 24-propidium iodide dye technique was not as accurate. The four dye techniques had comparable precision to plate counting, with the CellROX™ Green-propidium iodide dye having the greatest precision. The consistency of the position and shape of the cell clusters on the flow cytometry plots, and the extent of separation of the cell from background clusters, was greatest with the DiOC2 and CellROX™ Green-propidium iodide dyes. Furthermore, the DiOC2 and CellROX™ Green-propidium iodide dyes performed well, even when a sample was measured containing reconstituted whole milk powder at a 10-1 dilution, without the use of sample preparation to specifically remove the milk constituents prior to measurement. Given gating of only one cell cluster was required to be managed with the DiOC2 dye, to determine the viable number of cells, it was found that the DiOC2 dye had the greatest ease-of-use. Overall, results indicated that the DiOC2 dye is an ideal candidate for the enumeration of viable bacteria in dairy samples on a high-throughput, routine basis.
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Affiliation(s)
- Ben T Somerton
- Fonterra Research & Development Centre, Fonterra, Palmerston North, New Zealand.
| | - Brooke L Morgan
- Fonterra Research & Development Centre, Fonterra, Palmerston North, New Zealand
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2
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Catone S, Iannantuono S, Genovese D, Von Hunolstein C, Franciosa G. Viability-PCR for the selective detection of Lactobacillus acidophilus and Bifidobacterium bifidum in live bacteria-containing products. Front Microbiol 2024; 15:1400529. [PMID: 39021625 PMCID: PMC11251893 DOI: 10.3389/fmicb.2024.1400529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 06/21/2024] [Indexed: 07/20/2024] Open
Abstract
To exert their beneficial effects, microorganisms used in live bacteria-containing products must be viable and present in certain amounts. In this study, we developed a viability assay based on quantitative PCR coupled with propidium monoazide for the identification and enumeration of viable Lactobacillus acidophilus and Bifidobacterium bifidum. In order to optimize the protocol, the thermal inactivation conditions for the two target microorganisms and the PMA concentration inhibiting DNA amplification from the dead cells while allowing it from the live cells were first determined. The viability-PCR protocol was then applied to analyze a commercial product containing the two microorganisms. The quantities of both microorganisms determined using viability-PCR in the tested product were significantly higher than those obtained using the standard plate count, suggesting the presence of bacteria in a viable but non-culturable physiological state. Moreover, lower amounts of the two microorganisms were detected using viability-PCR compared to those achieved using quantitative PCR, possibly because of the presence of dead cells in the samples. Our results suggest that the viability-PCR method proposed here is a suitable alternative for rapid and accurate quantification and assessment of the viability of L. acidophilus and B. bifidum and could be easily adopted in the quality control screening of live bacteria-containing products.
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Affiliation(s)
| | | | | | | | - Giovanna Franciosa
- Biologicals and Biotechnologicals Unit, Istituto Superiore di Sanità, National Center for the Evaluation and Control of Medicines, Rome, Italy
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3
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Snaidr L, Mühlhahn P, Beimfohr C, Kreuzer C, Richly C, Snaidr J. Specific cultivation-independent enumeration of viable cells in probiotic products using a combination of fluorescence in situ hybridization and flow cytometry. Front Microbiol 2024; 15:1410709. [PMID: 38933029 PMCID: PMC11199854 DOI: 10.3389/fmicb.2024.1410709] [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: 04/01/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
This study introduces an optimized integration of flow cytometry and fluorescence in situ hybridization (Flow-FISH) as an approach for the specific enumeration of gram-positive bacteria in probiotic products, overcoming the limitations of conventional methods. The enhanced Flow-FISH technique synergizes the rapid and automated capabilities of flow cytometry with the high specificity of FISH, facilitating the differentiation of viable cells at the species level within probiotic blends. By analyzing lyophilized samples of Lacticaseibacillus rhamnosus, Lactiplantibacillus plantarum, and Bifidobacterium animalis subsp. lactis, and a commercial product, the study highlights the optimized Flow-FISH protocol's advantages, including reduced hybridization times to 1.5 h and elimination of centrifugation steps. Comparative evaluations with the widely accepted enumeration methods plate count and Live/Dead (L/D) staining were conducted. The study revealed that Flow-FISH produces higher viable cell counts than plate count, thereby challenging the traditional "gold standard" by highlighting its predisposition to underestimate actual viable cell numbers. Against L/D staining, Flow-FISH achieved comparable results, which, despite the different foundational premises of each technique, confirms the accuracy and reliability of our method. In conclusion, the optimized Flow-FISH protocol represents a significant leap forward in probiotic research and quality control. This method provides a rapid, robust, and highly specific alternative for the enumeration of probiotic bacteria, surpassing traditional methodologies. Its ability to enable a more detailed and reliable analysis of probiotic products paves the way for precise quality control and research insights, underscoring its potential to improve the field significantly.
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Sampaio KB, de Brito Alves JL, do Nascimento YM, Tavares JF, da Silva MS, Dos Santos Nascimento D, de Araújo Rodrigues NP, Monteiro MC, Garcia EF, de Souza EL. Effects of Simulated Gastrointestinal Conditions on Combined Potentially Probiotic Limosilactobacillus fermentum 296, Quercetin, and/or Resveratrol as Bioactive Components of Novel Nutraceuticals. Probiotics Antimicrob Proteins 2024; 16:308-319. [PMID: 36708461 DOI: 10.1007/s12602-023-10046-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2023] [Indexed: 01/29/2023]
Abstract
This study evaluated the effects of simulated gastrointestinal conditions (SGIC) on combined potentially probiotic Limosilactobacillus fermentum 296 (~ 10 log CFU/mL), quercetin (QUE, 160 mg), and/or resveratrol (RES, 150 mg) as the bioactive components of novel nutraceuticals. Four different nutraceuticals were evaluated during exposure to SGIC and analyzed the plate counts and physiological status of L. fermentum 296, contents and bioaccessibility of QUE and RES, and antioxidant capacity. Nutraceuticals with QUE and RES had the highest plate counts (4.94 ± 0.32 log CFU/mL) and sizes of live cell subpopulations (28.40 ± 0.28%) of L. fermentum 296 after SGIC exposure. An index of injured cells (Gmean index, arbitrary unit defined as above 0.5) indicated that part of L. fermentum 296 cells could be entered the viable but nonculturable state when the nutraceuticals were exposed to gastric and intestinal conditions while maintaining vitality. The nutraceuticals maintained high contents (QUE ~ 29.17 ± 0.62 and RES ~ 23.05 mg/100 g) and bioaccessibility (QUE ~ 41.0 ± 0.09% and RES ~ 67.4 ± 0.17%) of QUE and RES, as well as high antioxidant capacity (ABTS assay ~ 88.18 ± 1.16% and DPPH assay 75.54 ± 0.65%) during SGIC exposure, which could be linked to the protective effects on L. fermentum 296 cells. The developed nutraceuticals could cross along the gastrointestinal tract with high concentrations of functioning potentially probiotic cells and bioavailable phenolic compounds to exert their beneficial impacts on consumer health, being an innovative strategy for the co-ingestion of these bioactive components.
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Affiliation(s)
- Karoliny Brito Sampaio
- Department of Nutrition, Health Sciences Center, Federal University of Paraíba, Campus I - Cidade Universitária, CEP, João Pessoa, PB, 58051-900, Brazil
| | - José Luiz de Brito Alves
- Department of Nutrition, Health Sciences Center, Federal University of Paraíba, Campus I - Cidade Universitária, CEP, João Pessoa, PB, 58051-900, Brazil
| | | | - Josean Fechine Tavares
- Institute for Research in Drugs and Medicines, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Marcelo Sobral da Silva
- Institute for Research in Drugs and Medicines, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Davi Dos Santos Nascimento
- Department of Nutrition, Health Sciences Center, Federal University of Paraíba, Campus I - Cidade Universitária, CEP, João Pessoa, PB, 58051-900, Brazil
| | | | - Mariana Costa Monteiro
- Laboratory of Functional Foods, Institute of Nutrition, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Estefânia Fernandes Garcia
- Department of Gastronomy, Center of Technology and Regional Development, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Evandro Leite de Souza
- Department of Nutrition, Health Sciences Center, Federal University of Paraíba, Campus I - Cidade Universitária, CEP, João Pessoa, PB, 58051-900, Brazil.
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Ma X, Wang L, Dai L, Kwok LY, Bao Q. Rapid Detection of the Activity of Lacticaseibacillus Casei Zhang by Flow Cytometry. Foods 2023; 12:foods12061208. [PMID: 36981135 PMCID: PMC10048587 DOI: 10.3390/foods12061208] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/04/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023] Open
Abstract
Food processing, e.g., freeze-drying, exerts strong pressure on bacteria in the food matrix, decreasing their viability/activity and even forcing them to become viable but unculturable (VBNC), which are often underestimated by traditional plate count. The strict standards of bacterial viability in probiotic products require accurate cell viability/activity enumeration. We developed a staining (5(6)-carboxyfluorescein diacetate succinimide ester, propidium iodide)-based flow cytometry rapid method for detecting the viability/activity of Lacticaseibacillus (Lb.) casei Zhang, a widely used probiotic in the dairy industry in China. We optimized the procedural and instrumental parameters for generating results comparable to that of standard plate counts. This method was also applied to freeze-dried Lb. casei Zhang, yielding 7.7 × 1011 CFU/g, which was non-significantly higher than the results obtained by plate count (6.4 × 1011 CFU/g), possibly due to the detection of VBNC cells in the freeze-dried powder. We anticipated that this method can be used for detecting lactic acid bacteria in other probiotic food/beverages.
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Affiliation(s)
- Xuebo Ma
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Lina Wang
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Lixia Dai
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Lai-Yu Kwok
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Qiuhua Bao
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
- Correspondence: ; Tel.: +86-47-1430-0591; Fax: +86-47-1430-5357
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Tracey H, Coates N, Hulme E, John D, Michael DR, Plummer SF. Insights into the enumeration of mixtures of probiotic bacteria by flow cytometry. BMC Microbiol 2023; 23:48. [PMID: 36849905 PMCID: PMC9969615 DOI: 10.1186/s12866-023-02792-2] [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: 10/07/2022] [Accepted: 02/13/2023] [Indexed: 03/01/2023] Open
Abstract
The use of flow cytometry to enumerate microorganisms is gaining traction over the traditional plate count technique on the basis of superior accuracy, precision and time-to-result. Here, we assessed the suitability of live/dead flow cytometry for the enumeration of mixed populations of probiotic bacteria (L. acidophilus, L. paracasei, L. plantarum, L. salivarius, B. lactis and B. bifidum) whilst comparing outcomes with plate counting. Using a novel gating strategy designed specifically for the enumeration of mixed populations, the application of flow cytometry resulted in the detection of higher numbers of viable bacteria with a greater level of repeatability than plate counting (RSD of 6.82 and 13.14% respectively). Across all multi-species blends tested, viable cell input was more accurately recovered by flow cytometry (101.8 ± 6.95%) than plate counts (81.37 ± 16.03%). However, when certain probiotic mixtures contained preparations with high numbers of non-viable cells in their total population, flow cytometry had the potential for overestimation of the viable population. Nevertheless, the comparative plate counts of these mixtures were low and variable, thus supporting the use of flow cytometry for the enumeration of viable bacteria in mixed populations.
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Affiliation(s)
- Harry Tracey
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK
| | - Niall Coates
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK.
| | - Eleri Hulme
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK
| | - Daniel John
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK
| | - Daryn Robert Michael
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK
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Visciglia A, Allesina S, Amoruso A, De Prisco A, Dhir R, Bron PA, Pane M. Assessment of shelf-life and metabolic viability of a multi-strain synbiotic using standard and innovative enumeration technologies. Front Microbiol 2022; 13:989563. [PMID: 36406457 PMCID: PMC9672074 DOI: 10.3389/fmicb.2022.989563] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/27/2022] [Indexed: 11/15/2023] Open
Abstract
The number of live bacterial cells is the most used parameter to assess the quality of finished probiotic products. Plate counting (PC) is the standard method in industry to enumerate cells. Application of PC implies critical aspects related to the selection of optimal nutrient media and growth conditions and underestimation of viable but not cultivable (VBNC) cells. Flow-cytometry (FC) is a culture-independent methodology having the potential to selectively enumerate live, damaged, and dead cells representing a powerful tool for in-depth monitoring of probiotic products. We monitored the shelf life of a clinical batch of a synbiotic composition PDS-08 targeting the pediatric population by means of PC and FC according to International Conference on Harmonization (ICH) pharma guidelines testing the Arrhenius model as predictive tool; PC enumeration revealed higher destruction rate than FC suggesting a faster reduction in cultivability than membrane integrity and thus a possible shift of the bacteria into a VBNC status. PDS-08 maintained acidification capability over time, when re-suspended in nutrient medium, even in samples tested sub-optimally for CFU detection (below 1 billion cells/dose). Due to similar kinetics described by the study of metabolic activity and membrane integrity, FC might be suggested as a valid tool for the study of functional stability of a probiotic product.
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Affiliation(s)
| | | | - Angela Amoruso
- Probiotical Research S.r.l., Enrico Mattei, Novara, Italy
| | | | - Raja Dhir
- Seed Health, Abbot Kinney Blvd, Los Angeles, CA, United States
| | - Peter A. Bron
- Seed Health, Abbot Kinney Blvd, Los Angeles, CA, United States
| | - Marco Pane
- Probiotical Research S.r.l., Enrico Mattei, Novara, Italy
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Shi Z, Li X, Fan X, Xu J, Liu Q, Wu Z, Pan D. PMA-qPCR method for the selective quantitation of viable lactic acid bacteria in fermented milk. Front Microbiol 2022; 13:984506. [PMID: 36160254 PMCID: PMC9491339 DOI: 10.3389/fmicb.2022.984506] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 08/15/2022] [Indexed: 11/13/2022] Open
Abstract
The number of viable lactic acid bacteria (LAB) is a key indicator of the quality of fermented milk. Currently, the combination of propidium monoazide (PMA) and qPCR has been applied in the quantification of viable bacteria in various matrices. In this research, the PMA-qPCR method was used to detect the number of viable bacteria of each LAB species in fermented milk. By analyzing pheS gene and 16S rRNA gene sequence similarities in five species of LAB, namely Lactobacillus delbrueckii subsp. bulgaricus, Lactiplantibacillus plantarum, Streptococcus thermophilus, Lactobacillus helveticus, and Lactococcus lactis subsp. lactis, the pheS gene resolved species identities better and was thus selected to design specific primers and probes. The pheS gene was cloned into the pUC19 vector and used to construct a standard curve for absolute quantification. Standard curves for quantification were constructed for each LAB species for serial dilutions between 1011 and 106 CFU/mL, with R2 > 0.99. The number of viable bacteria in the fermented milk detected by PMA-qPCR was significantly lower than that of qPCR (P < 0.05), indicating that PMA inhibited the amplification of DNA from dead cells. This was corroborated by the results from bacterial staining and plate count experiments. The proposed PMA-qPCR method provided rapid qualitative and quantitative determination of the number of viable bacteria for each LAB species in fermented milk within 3 h.
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Affiliation(s)
- Zihang Shi
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, China
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Xiefei Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, China
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Xiankang Fan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, China
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Jue Xu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, China
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Qing Liu
- Nanjing Dairy Group, Nanjing, China
| | - Zhen Wu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, China
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
- *Correspondence: Zhen Wu,
| | - Daodong Pan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, China
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
- Daodong Pan,
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Guo J, Zhu J, Zhao T, Sun Z, Song S, Zhang Y, Zhu D, Cao S, Deng X, Chai Y, Sun Y, Maratbek S, Chen C, Liu L, Zhang H. Survival characteristics and transcriptome profiling reveal the adaptive response of the Brucella melitensis 16M biofilm to osmotic stress. Front Microbiol 2022; 13:968592. [PMID: 36060772 PMCID: PMC9428795 DOI: 10.3389/fmicb.2022.968592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 07/28/2022] [Indexed: 11/13/2022] Open
Abstract
Brucella can inhabit hostile environments, including osmotic stress. How Brucella responds collectively to osmotic stress is largely unexplored, particularly in spatially structured communities such as a biofilm. To gain insight into this growth mode, we set out to characterize the Brucella melitensis 16M biofilm, describe its phenotype, and carry out a comparative transcriptomic analysis between biofilms under osmotic stress and control conditions. We determined that the bacteria challenged with 1.5 M NaCl had a reduced ability to aggregate and form clumps and develop a biofilm; however, the salt stress promoted the release of the outer membrane vesicles from the biofilm. Together with the genotypical response to osmotic stress, we identified 279 differentially expressed genes in B. melitensis 16M grown under osmotic conditions compared with control conditions; 69 genes were upregulated and 210 downregulated. Under osmotic stress, the main changed genes of biofilm were predicted to be involved in flagellar assembly, cell envelope, translation, small RNA regulation, transport and binding proteins, and energy metabolism. In addition, the ABC transporter was enriched in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We highlight 12 essential ABC transporter genes associated with a bacterial response to osmotic stress at the biofilm stage, including one specific locus, BME_RS12880, mediating betaine accumulation in biofilms to eliminate osmotic stress. The current study results can help researchers gain insights into B. melitensis 16M biofilm adaptation to osmotic stress and provide information for developing intervention strategies to control Brucella.
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Affiliation(s)
- Jia Guo
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Jiale Zhu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Tianyi Zhao
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Zhihua Sun
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Shengnan Song
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Yu Zhang
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Dexin Zhu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Shuzhu Cao
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Xingmei Deng
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Yingjin Chai
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Yongxue Sun
- Collaborative Innovation Center for Sheep Healthy Farming and Zoonotic Disease Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Suleimenov Maratbek
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
- College of Veterinary, National Agricultural University of Kazakhstan, Nur-Sultan, Kazakhstan
| | - Chuangfu Chen
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Liangbo Liu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
- *Correspondence: Liangbo Liu,
| | - Hui Zhang
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
- Hui Zhang,
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10
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Accurate and online quantification of viable Rhodobacter sphaeroides cells using a flow cytometry-dielectric spectroscopy (FCM-DS) method. Talanta 2022; 245:123448. [DOI: 10.1016/j.talanta.2022.123448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 03/27/2022] [Accepted: 04/02/2022] [Indexed: 11/23/2022]
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Lugli GA, Longhi G, Alessandri G, Mancabelli L, Tarracchini C, Fontana F, Turroni F, Milani C, Di Pierro F, van Sinderen D, Ventura M. The Probiotic Identity Card: A Novel “Probiogenomics” Approach to Investigate Probiotic Supplements. Front Microbiol 2022; 12:790881. [PMID: 35126330 PMCID: PMC8814603 DOI: 10.3389/fmicb.2021.790881] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/14/2021] [Indexed: 12/19/2022] Open
Abstract
Probiotic bacteria are widely administered as dietary supplements and incorporated as active ingredients in a variety of functional foods due to their purported health-promoting features. Currently available probiotic products may have issues with regards to their formulation, such as insufficient levels of viable probiotic bacteria, complete lack of probiotic strains that are stated to be present in the product, and the presence of microbial contaminants. To avoid the distribution of such unsuitable or misleading products, we propose here a novel approach named Probiotic Identity Card (PIC), involving a combination of shotgun metagenomic sequencing and bacterial cell enumeration by flow cytometry. PIC was tested on 12 commercial probiotic supplements revealing several inconsistencies in the formulation of five such products based on their stated microbial composition and viability.
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Affiliation(s)
- Gabriele Andrea Lugli
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
| | - Giulia Longhi
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
- GenProbio Srl, Parma, Italy
| | - Giulia Alessandri
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
| | - Leonardo Mancabelli
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
| | - Chiara Tarracchini
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
| | - Federico Fontana
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
- GenProbio Srl, Parma, Italy
| | - Francesca Turroni
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
- Microbiome Research Hub, University of Parma, Parma, Italy
| | - Christian Milani
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
- Microbiome Research Hub, University of Parma, Parma, Italy
| | - Francesco Di Pierro
- Velleja Research, Milan, Italy
- Digestive Endoscopy Unit and Gastroenterology, Fondazione Poliambulanza, Brescia, Italy
| | - Douwe van Sinderen
- APC Microbiome Institute and School of Microbiology, Bioscience Institute, National University of Ireland, Cork, Ireland
| | - Marco Ventura
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
- Microbiome Research Hub, University of Parma, Parma, Italy
- *Correspondence: Marco Ventura,
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Dynamics of physiological responses of potentially probiotic fruit-derived Limosilactobacillus fermentum in apple and orange juices during refrigeration storage and exposure to simulated gastrointestinal conditions. Arch Microbiol 2021; 204:38. [DOI: 10.1007/s00203-021-02672-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/01/2021] [Accepted: 10/18/2021] [Indexed: 11/26/2022]
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13
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Supranational Assessment of the Quality of Probiotics: Collaborative Initiative between Independent Accredited Testing Laboratories. Microorganisms 2021; 9:microorganisms9071456. [PMID: 34361892 PMCID: PMC8305042 DOI: 10.3390/microorganisms9071456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 11/17/2022] Open
Abstract
Recent acquisitions about the role of the microbiota in the functioning of the human body make it possible to envisage an increasing use of beneficial microbes, and more particularly of probiotics as well as their metabolites, as nutritional supplements. National and EU authorities are engaged in assuring the safety and quality of food supplements and in defining rules to assess and communicate their efficacy on human health. The quality of probiotics, intended as strains' identification, viability, and stability over time, is a crucial factor of credibility with consumers and health professionals. Analytical technologies for the quality control of probiotics must also be adapted to new preparations, such as those including new multistrains complex combinations. Accredited laboratories face this relevant challenge on a daily basis. Through its close collaboration with the laboratory commissioned to produce the specifications for its ESLP quality label (identification and quantitative analyses) together with its scientific committee, the ESLP has been focusing on this issue for 10 years. Recently, as part of the internationalization of the ESLP quality label, a new and unique initiative in Europe for the evaluation of the quality of probiotic preparations has been carried out. The collaboration between two accredited laboratories in Belgium and in Italy represented a concrete example of supranational collaboration in the assessment of the quality of probiotic preparations. Results show that both laboratories are in line as expected in terms of performance. Common approaches to the qualitative assessment of probiotic preparations, especially for complex and composite recipes, in terms of number of strains and included substances, should be encouraged and promoted all over the EU.
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Siciliano RA, Reale A, Mazzeo MF, Morandi S, Silvetti T, Brasca M. Paraprobiotics: A New Perspective for Functional Foods and Nutraceuticals. Nutrients 2021; 13:1225. [PMID: 33917707 PMCID: PMC8068161 DOI: 10.3390/nu13041225] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/30/2021] [Accepted: 03/31/2021] [Indexed: 12/15/2022] Open
Abstract
Probiotics are live microorganisms that confer health benefits on the host. However, in recent years, several concerns on their use have been raised. In particular, industrial processing and storage of probiotic products are still technological challenges as these could severely impair cell viability. On the other hand, safety of live microorganisms should be taken into account, especially when administered to vulnerable people, such as the elderly and immunodeficient individuals. These drawbacks have enhanced the interest toward new products based on non-viable probiotics such as paraprobiotics and postbiotics. In particular, paraprobiotics, defined as "inactivated microbial cells (non-viable) that confer a health benefit to the consumer," hold the ability to regulate the adaptive and innate immune systems, exhibit anti-inflammatory, antiproliferative and antioxidant properties and exert antagonistic effect against pathogens. Moreover, paraprobiotics can exhibit enhanced safety, assure technological and practical benefits and can also be used in products suitable for people with weak immunity and the elderly. These features offer an important opportunity to prompt the market with novel functional foods or nutraceuticals that are safer and more stable. This review provides an overview of central issues on paraprobiotics and highlights the urgent need for further studies aimed at assessing safety and efficacy of these products and their mechanisms of action in order to support decisions of regulatory authorities. Finally, a definition is proposed that unambiguously distinguishes paraprobiotics from postbiotics.
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Affiliation(s)
- Rosa Anna Siciliano
- Institute of Food Sciences, National Research Council (CNR-ISA), Via Roma 64, 83100 Avellino, Italy; (R.A.S.); (A.R.)
| | - Anna Reale
- Institute of Food Sciences, National Research Council (CNR-ISA), Via Roma 64, 83100 Avellino, Italy; (R.A.S.); (A.R.)
| | - Maria Fiorella Mazzeo
- Institute of Food Sciences, National Research Council (CNR-ISA), Via Roma 64, 83100 Avellino, Italy; (R.A.S.); (A.R.)
| | - Stefano Morandi
- Institute of Sciences of Food Production, National Research Council (CNR-ISPA), Via G. Celoria 2, 20133 Milan, Italy; (S.M.); (M.B.)
| | - Tiziana Silvetti
- Institute of Sciences of Food Production, National Research Council (CNR-ISPA), Via G. Celoria 2, 20133 Milan, Italy; (S.M.); (M.B.)
| | - Milena Brasca
- Institute of Sciences of Food Production, National Research Council (CNR-ISPA), Via G. Celoria 2, 20133 Milan, Italy; (S.M.); (M.B.)
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15
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Foglia C, Allesina S, Amoruso A, De Prisco A, Pane M. New insights in enumeration methodologies of probiotic cells in finished products. J Microbiol Methods 2020; 175:105993. [DOI: 10.1016/j.mimet.2020.105993] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 01/22/2023]
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16
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Jackson SA, Schoeni JL, Vegge C, Pane M, Stahl B, Bradley M, Goldman VS, Burguière P, Atwater JB, Sanders ME. Improving End-User Trust in the Quality of Commercial Probiotic Products. Front Microbiol 2019; 10:739. [PMID: 31105649 PMCID: PMC6499161 DOI: 10.3389/fmicb.2019.00739] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 03/25/2019] [Indexed: 01/09/2023] Open
Abstract
In a rapidly growing global probiotic market, end-users have difficulty distinguishing between high quality and poor quality products. This ambiguity threatens the trust consumers and healthcare providers have in probiotic products. To address this problem, we recommend that companies undergo third-party evaluations to certify probiotic quality and label accuracy. In order to communicate about product quality to end-users, indication of certification on product labels is helpful, although not all manufacturers choose to use this approach. Herein we discuss: third-party certification, the process of setting standards for identity, purity, and quantification of probiotics; some emerging methodologies useful for quality assessment; and some technical challenges unique to managing quality of live microbial products. This review provides insights of an Expert Panel engaged in this process and aims to update the reader on relevant current scientific methodologies. Establishing validated methodologies for all aspects of quality assessment is an essential component of this process and can be facilitated by established organizations, such as United States Pharmacopeia. Emerging methodologies including whole genome sequencing and flow cytometry are poised to play important roles in these processes.
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Affiliation(s)
- Scott A. Jackson
- National Institute of Standards and Technology, Gaithersburg, MD, United States
| | - Jean L. Schoeni
- Eurofins Food Integrity and Innovation, Madison, WI, United States
| | | | | | - Buffy Stahl
- DuPont Nutrition & Health, Madison, WI, United States
| | | | - Virginia S. Goldman
- Department of Dietary Supplements and Herbal Medicines, Science Division, US Pharmacopeial Convention, Rockville, MD, United States
| | | | | | - Mary Ellen Sanders
- International Scientific Association for Probiotics and Prebiotics, Sacramento, CA, United States
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