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Mahdizade Ari M, Scholz KJ, Cieplik F, Al-Ahmad A. Viable but non-cultivable state in oral microbiota: a critical review of an underexplored microbial survival strategy. Front Cell Infect Microbiol 2025; 15:1533768. [PMID: 40171166 PMCID: PMC11959090 DOI: 10.3389/fcimb.2025.1533768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2024] [Accepted: 02/19/2025] [Indexed: 04/03/2025] Open
Abstract
The viable but non-cultivable (VBNC) state and persister cells, two dormancy phenomena in bacteria, differ in various aspects. The entry of bacteria into the VBNC state as a survival strategy under stressful conditions has gained increasing attention in recent years, largely due to the higher tolerance of VBNC cells to antibiotics and antimicrobials resulting from their low metabolic activity. The oral cavity favors biofilm growth in dental hard tissues, resulting in tooth decay and periodontitis. Despite advances in VBNC state detection in the food industry and environment, the entry capability of oral bacteria into the VBNC state remains poorly documented. Furthermore, the VBNC state has recently been observed in oral pathogens, including Porphyromonas gingivalis, which shows potential relevance in chronic systemic infections, Enterococcus faecalis, an important taxon in endodontic infections, and Helicobacter pylori, which exhibits transient presence in the oral cavity. Further research could create opportunities to develop novel therapeutic strategies to control oral pathogens. The inability of conventional culture-based methods to identify VBNC bacteria and the metabolic reactivation of dormant cells to restore susceptibility to therapies highlights a notable gap in anti-VBNC state strategies. The lack of targeted approaches tested for efficacy against VBNC bacteria underscores the need to develop novel detection methods. This review discusses the VBNC state, its importance in public health, and diagnostic techniques, with a special focus on the VBNC state in oral bacteria.
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Affiliation(s)
- Marzie Mahdizade Ari
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Konstantin Johannes Scholz
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg im Breisgau, Germany
| | - Fabian Cieplik
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg im Breisgau, Germany
| | - Ali Al-Ahmad
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg im Breisgau, Germany
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Aurongzeb M, Fatima SZ, Hussain SI, Rashid Y, Aziz T, Alhomrani M, Alsanie WF, Alamri AS. Detection and identification of Naegleria species along with Naegleria fowleri in the tap water samples. BMC Med Genomics 2025; 18:6. [PMID: 39780139 PMCID: PMC11716488 DOI: 10.1186/s12920-024-02068-2] [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: 05/07/2024] [Accepted: 12/13/2024] [Indexed: 01/11/2025] Open
Abstract
Naegleria fowleri, the causative agent of Primary Amoebic Meningoencephalitis (PAM), is commonly found in warm freshwater environments and can enter the brain through nasal passages during activities like swimming or ablution. PAM has a high fatality rate, raising concerns about its global health impact. In Pakistan, particularly in Karachi, a significant number of cases have been reported, often with no history of recreational water exposure, but with regular ablution using tap water. This study analyzed the physicochemical parameters, abundance of total and fecal coliforms, and detected N. fowleri and other Naegleria species in tap water samples from Karachi using PCR with ITS- and Naegl-primers. Almost all samples exhibited high temperatures, low chlorine levels, and a high presence of coliforms. N. fowleri and other Naegleria species were detected in 11 out of 39 samples. Sequence analysis identified N. fowleri in tap water from the Golimar and Lyari areas of Karachi, while the other nine samples revealed different Naegleria species. This study suggests that the combination of high temperatures, insufficient chlorination, and the presence of coliforms may create favorable conditions for N. fowleri growth. However, these factors are not exclusive to the Golimar and Lyari areas, indicating that other environmental or infrastructural factors, not detailed in this study, may have contributed to the presence of N. fowleri in that specific location.
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Affiliation(s)
- Muhammad Aurongzeb
- Department of Biotechnology, Faculty of Engineering Science and Technology, Hamdard University, Karachi, 74600, Pakistan
| | | | - Syed Ikhlaq Hussain
- Department of Zoology, Federal Urdu University of Arts, Science and Technology, Gulshan-E-Iqbal, Karachi, Pakistan
| | - Yasmeen Rashid
- Department of Biochemistry, University of Karachi, Karachi, 75270, Pakistan.
| | - Tariq Aziz
- Laboratory of Animal Health Food Hygiene and Quality, University of Ioannina, Arta, 47132, Greece
| | - Majid Alhomrani
- Department of Clinical Laboratory Sciences, The Faculty of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Walaa F Alsanie
- Department of Clinical Laboratory Sciences, The Faculty of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Abdulhakeem S Alamri
- Department of Clinical Laboratory Sciences, The Faculty of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
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3
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Tang MLY, Lau SCK. Effects of chlorination on the survival of sewage bacteria in seawater microcosms. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13216. [PMID: 37990630 PMCID: PMC10866060 DOI: 10.1111/1758-2229.13216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 11/03/2023] [Indexed: 11/23/2023]
Abstract
Chlorination is a commonly used disinfection method in sewage treatment process. However, resistant bacteria may survive chlorination and enter the receiving aquatic environment upon effluent discharge. There has been limited research on the effects of chlorination on bacterial survival in seawater. To address this knowledge gap, microcosm experiments were conducted to simulate the discharge of chlorinated effluents into coastal seawater. The results revealed that bacterial communities in seawater-based effluents survived better in seawater than those in freshwater-based effluents. High chlorine dosages could significantly reduce the viable bacterial populations and their chance of regrowth in seawater. Additionally, faecal indicator bacteria (FIB) that entered the viable but non-culturable (VBNC) state under chlorination tended to persist in the VBNC state without resuscitation during seawater incubation. Because of the prevalence of VBNC indicator bacteria, qPCR quantification of FIB was more effective than conventional culture-based methods in tracing viable pathogenic chlorine-resistant bacteria, although the correlation strength varied depending on the type of effluent. This study sheds light on how chlorine dosages and the intrinsic properties of effluents affect bacterial survival in seawater and highlights the potential and limitations of using FIB in monitoring the health risks associated with the discharge of chlorinated effluents.
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Affiliation(s)
- Mandy Lok Yi Tang
- Department of Ocean ScienceHong Kong University of Science and TechnologyHong KongChina
| | - Stanley Chun Kwan Lau
- Department of Ocean ScienceHong Kong University of Science and TechnologyHong KongChina
- Center for Ocean Research in Hong Kong and MacauHong Kong University of Science and TechnologyHong KongChina
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Kemper MA, Veenman C, Blaak H, Schets FM. A membrane filtration method for the enumeration of Escherichia coli in bathing water and other waters with high levels of background bacteria. JOURNAL OF WATER AND HEALTH 2023; 21:995-1003. [PMID: 37632376 PMCID: wh_2023_004 DOI: 10.2166/wh.2023.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/28/2023]
Abstract
The presence and level of faecal indicator bacteria are important factors in estimating the microbiological quality of surface water and the risk of human infection upon exposure to this water. Until 2014, ISO 9308-1:2000 was available and used to enumerate faecal indicator Escherichia coli in bathing water. In 2014, this ISO was technically revised and replaced by ISO 9308-1:2014. This ISO introduced a less selective method for enumeration of E. coli that allows non-specific growth from waters containing high levels of bacteria, such as surface waters. This implies that currently there is no suitable reference membrane filtration method for the compliance monitoring of official bathing sites for E. coli according to the European Bathing Water Directive. Here, the performance characteristics of three chromogenic culture media, namely Tryptone Bile X-glucuronide (TBX) agar, Chromogenic Coliform Agar (CCA), and CHROMagar E. coli/Coliform (ECC) were investigated at 44 °C for water with varying levels of bacteria according to ISO 13843:2017. Based on performance characteristics, colony counts, and practical usage, TBX appeared the most suitable culture medium for the enumeration of E. coli in bathing water and other waters with high levels of background bacteria, such as surface water in agricultural areas and wastewater discharge points.
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Affiliation(s)
- Merel A Kemper
- National Institute for Public Health and the Environment (RIVM), Centre for Infectious Disease Control, P.O. Box 1, 3720 BA Bilthoven, The Netherlands E-mail:
| | - Christiaan Veenman
- National Institute for Public Health and the Environment (RIVM), Centre for Infectious Disease Control, P.O. Box 1, 3720 BA Bilthoven, The Netherlands
| | - Hetty Blaak
- National Institute for Public Health and the Environment (RIVM), Centre for Infectious Disease Control, P.O. Box 1, 3720 BA Bilthoven, The Netherlands
| | - Franciska M Schets
- National Institute for Public Health and the Environment (RIVM), Centre for Infectious Disease Control, P.O. Box 1, 3720 BA Bilthoven, The Netherlands
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Otsuka K, Seike T, Toya Y, Ishii J, Hirono-Hara Y, Hara KY, Matsuda F. Evolutionary approach for improved proton pumping activity of heterologous rhodopsin expressed in Escherichia coli. J Biosci Bioeng 2022; 134:484-490. [PMID: 36171161 DOI: 10.1016/j.jbiosc.2022.08.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/29/2022] [Accepted: 08/17/2022] [Indexed: 12/13/2022]
Abstract
A light-driven ATP regeneration system using rhodopsin has been utilized as a method to improve the production of useful substances by microorganisms. To enable the industrial use of this system, the proton pumping rate of rhodopsin needs to be enhanced. Nonetheless, a method for this enhancement has not been established. In this study, we attempted to develop an evolutionary engineering method to improve the proton-pumping activity of rhodopsins. We first introduced random mutations into delta-rhodopsin (dR) from Haloterrigena turkmenica using error-prone PCR to generate approximately 7000 Escherichia coli strains carrying the mutant dR genes. Rhodopsin-expressing E. coli with enhanced proton pumping activity have significantly increased survival rates in prolonged saline water. Considering this, we enriched the mutant E. coli cells with higher proton pumping rates by selecting populations able to survive starvation under 50 μmol m-2 s-1 at 37 °C. As a result, we successfully identified two strains, in which proton pumping activity was enhanced two-fold by heterologous expression in E. coli in comparison to wild-type strains. The combined approach of survival testing using saline water and evolutionary engineering methods used in this study will contribute greatly to the discovery of a novel rhodopsin with improved proton pumping activity. This will facilitate the utilization of rhodopsin in industrial applications.
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Affiliation(s)
- Kensuke Otsuka
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Taisuke Seike
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yoshihiro Toya
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Jun Ishii
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan; Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Yoko Hirono-Hara
- Department of Environmental and Life Sciences, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga, Shizuoka 422-8526, Japan
| | - Kiyotaka Y Hara
- Department of Environmental and Life Sciences, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga, Shizuoka 422-8526, Japan; Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga, Shizuoka 422-8526, Japan
| | - Fumio Matsuda
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Santander RD, Khodadadi F, Meredith CL, Rađenović Ž, Clements J, Aćimović SG. Fire blight resistance, irrigation and conducive wet weather improve Erwinia amylovora winter survival in cankers. Front Microbiol 2022; 13:1009364. [PMID: 36329850 PMCID: PMC9623323 DOI: 10.3389/fmicb.2022.1009364] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/21/2022] [Indexed: 07/30/2023] Open
Abstract
Erwinia amylovora causes fire blight, a disease responsible for enormous economic losses in the pome fruit-producing areas where it is present. Despite the abundant research on fire blight, information about E. amylovora population dynamics and survival in fire blight cankers and the plant defense responses to this pathogen in the infected bark are limited. In our study, we obtained fire blight cankers in apple, pear, and Asian pear cultivars showing differing resistance to the disease by shoot inoculation with E. amylovora. We collected cankers from irrigated and non-irrigated trees every 3 months in two independent field experiments and analyzed samples by viability digital PCR. We also assessed the expression of pathogenicity-related (PR) genes in the bark of selected apple and Asian pear cultivars. A logistic regression analysis revealed the impact of environmental and host factors on E. amylovora detection rates in cankers. The chances of detecting live E. amylovora cells in cankers increased significantly in those collected from irrigated trees, in July, and/or during an experiment performed in a year with an expected average rainfall when compared to samples from non-irrigated trees, collected in January, and/or during an experiment performed under environmental conditions dominated by drought. We found a positive correlation between the pathogen detection rates in cankers and the host resistance to fire blight that might be explained by lower E. amylovora survival rates in more damaged tissues of susceptible hosts. The genes PR-1, PR-2, PR-5, and PR-8 were induced in the bark surrounding apple and Asian pear fire blight cankers. Our study, involving the analysis of more than 800 canker samples, provides new knowledge about the fire blight disease cycle and lays the foundation for improved fire blight management and eradication strategies in pome fruit orchards.
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Affiliation(s)
- Ricardo D. Santander
- Irrigated Agriculture Research and Extension Center, College of Agricultural, Human, and Natural Resource Sciences, Washington State University, Prosser, WA, United States
- Hudson Valley Research Laboratory, School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Highland, NY, United States
| | - Fatemeh Khodadadi
- Alson H. Smith Jr. Agricultural Research and Extension Center, School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Winchester, VA, United States
| | - Christopher L. Meredith
- Hudson Valley Research Laboratory, School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Highland, NY, United States
| | - Željko Rađenović
- Hudson Valley Research Laboratory, School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Highland, NY, United States
| | - Jon Clements
- Center for Agriculture, Food, and the Environment, University of Massachusetts Amherst, UMass Cold Spring Orchard, Belchertown, MA, United States
| | - Srđan G. Aćimović
- Alson H. Smith Jr. Agricultural Research and Extension Center, School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Winchester, VA, United States
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7
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Mahaney AP, Franklin RB. Persistence of wastewater-associated antibiotic resistant bacteria in river microcosms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 819:153099. [PMID: 35038511 DOI: 10.1016/j.scitotenv.2022.153099] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/08/2022] [Accepted: 01/10/2022] [Indexed: 06/14/2023]
Abstract
The spread of antibiotic-resistant bacteria (ARB) associated with wastewater is a significant environmental concern, but little is known about the persistence and proliferation of these organisms in receiving water bodies after discharge. To address this knowledge gap, we performed a series of microcosm experiments in which river water was amended with either untreated or treated wastewater, and the abundance of viable ciprofloxacin-, Bactrim-, and erythromycin-resistant bacteria was monitored for 72 h. Both types of wastewater amendments significantly increased the initial abundance of ARB compared to microcosms containing only river water (all p < 0.03). The increase was greatest with untreated wastewater, but that effect decreased steadily over time. In contrast, microcosms amended with treated wastewater saw a smaller initial increase and more complex temporal dynamics. Following a brief lag, ARB abundance bloomed for all three of the antibiotics that we considered. This suggests that ARB that survive wastewater treatment are particularly hardy and may proliferate in riverine conditions after a short recovery period. To determine how interactions with the native river microbial community impacted the persistence of wastewater-associated ARB, an additional set of microcosms was prepared using filter-sterilized river water. Peak abundance in these microcosms was significantly higher by 1-2 orders of magnitude compared to microcosms containing an intact river microbial community (all p < 0.05), which suggests that biotic interactions play a significant role in regulating the persistence and proliferation of ARB. The data presented in this paper are among the first available that specifically consider persistence of viable ARB and represent an important step toward understanding AR-related human health risks downstream from wastewater discharge points and following sewer overflow events. Additional studies that consider longer time scales and the interplay of biotic and abiotic variables are essential for modeling public health risks associated with wastewater inputs of ARB to rivers and other aquatic environments.
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Affiliation(s)
- Aoife P Mahaney
- Department of Biology, Virginia Commonwealth University, 1000 W Cary Street, Richmond, Virginia 23284, USA
| | - Rima B Franklin
- Department of Biology, Virginia Commonwealth University, 1000 W Cary Street, Richmond, Virginia 23284, USA.
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Zhang XH, Ahmad W, Zhu XY, Chen J, Austin B. Viable but nonculturable bacteria and their resuscitation: implications for cultivating uncultured marine microorganisms. MARINE LIFE SCIENCE & TECHNOLOGY 2021; 3:189-203. [PMID: 37073345 PMCID: PMC10077291 DOI: 10.1007/s42995-020-00041-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 03/25/2020] [Indexed: 05/03/2023]
Abstract
Culturing has been the cornerstone of microbiology since Robert Koch first successfully cultured bacteria in the late nineteenth century. However, even today, the majority of microorganisms in the marine environment remain uncultivated. There are various explanations for the inability to culture bacteria in the laboratory, including lack of essential nutrients, osmotic support or incubation conditions, low growth rate, development of micro-colonies, and the presence of senescent or viable but nonculturable (VBNC) cells. In the marine environment, many bacteria have been associated with dormancy, as typified by the VBNC state. VBNC refers to a state where bacteria are metabolically active, but are no longer culturable on routine growth media. It is apparently a unique survival strategy that has been adopted by many microorganisms in response to harsh environmental conditions and the bacterial cells in the VBNC state may regain culturability under favorable conditions. The resuscitation of VBNC cells may well be an important way to cultivate the otherwise uncultured microorganisms in marine environments. Many resuscitation stimuli that promote the restoration of culturability have so far been identified; these include sodium pyruvate, quorum sensing autoinducers, resuscitation-promoting factors Rpfs and YeaZ, and catalase. In this review, we focus on the issues associated with bacterial culturability, the diversity of bacteria entering the VBNC state, mechanisms of induction into the VBNC state, resuscitation factors of VBNC cells and implications of VBNC resuscitation stimuli for cultivating these otherwise uncultured microorganisms. Bringing important microorganisms into culture is still important in the era of high-throughput sequencing as their ecological functions in the marine environment can often only be known through isolation and cultivation.
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Affiliation(s)
- Xiao-Hua Zhang
- College of Marine Life Sciences and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071 China
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266100 China
| | - Waqar Ahmad
- College of Marine Life Sciences and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Xiao-Yu Zhu
- College of Marine Life Sciences and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Jixiang Chen
- School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, 730050 China
| | - Brian Austin
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA Scotland, UK
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Mohsina K, Kaur M, Bowman JP, Powell S, Tamplin ML. qPCR quantification of Carnobacterium maltaromaticum, Brochothrix thermosphacta, and Serratia liquefaciens growth kinetics in mixed culture. J Microbiol Methods 2020; 175:105961. [PMID: 32479869 DOI: 10.1016/j.mimet.2020.105961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/18/2020] [Accepted: 05/18/2020] [Indexed: 10/24/2022]
Abstract
Quantifying growth kinetics of specific spoilage microorganisms in mixed culture is required to describe the evolution of food microbiomes. A qPCR method was developed to selectively amplify individual meat spoilage bacteria, Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens, within a broth medium designed to simulate the composition of beef. An optimized method of DNA extraction was produced for standard curve construction. Method specificity was determined by individual single peaks in melt curves. Reaction efficiency for standard curves of C. maltaromaticum, B. thermosphacta and S. liquefaciens was high (R2 = 0.98-0.99), and linear quantification was achieved over a 5 log CFU/ml range. Coefficient of variation was calculated considering both threshold cycle (Ct) and bacterial concentration; the value did not exceed 14% for inter- or intra-runs for either method. Comparison of growth kinetic parameters derived from plate count and qPCR showed no significant variation (P > .05) for growth rate (GR) and maximum population density (MPD); lag phase duration (LPD) was not included in this comparison due to high innate variability. Log quantification of each isolate was validated in a mixed-culture experiment for all three species with qPCR and plate count differing less than 0.3 log CFU/ml (average 0.10 log CFU/ml, R2 = 0.98).
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Affiliation(s)
- Kaniz Mohsina
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, Tasmania 7001, Australia.
| | - Mandeep Kaur
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, Tasmania 7001, Australia.
| | - John P Bowman
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, Tasmania 7001, Australia.
| | - Shane Powell
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, Tasmania 7001, Australia.
| | - Mark L Tamplin
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, Tasmania 7001, Australia.
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Bogatyrev SR, Rolando JC, Ismagilov RF. Self-reinoculation with fecal flora changes microbiota density and composition leading to an altered bile-acid profile in the mouse small intestine. MICROBIOME 2020; 8:19. [PMID: 32051033 PMCID: PMC7017497 DOI: 10.1186/s40168-020-0785-4] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/05/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND The upper gastrointestinal tract plays a prominent role in human physiology as the primary site for enzymatic digestion and nutrient absorption, immune sampling, and drug uptake. Alterations to the small intestine microbiome have been implicated in various human diseases, such as non-alcoholic steatohepatitis and inflammatory bowel conditions. Yet, the physiological and functional roles of the small intestine microbiota in humans remain poorly characterized because of the complexities associated with its sampling. Rodent models are used extensively in microbiome research and enable the spatial, temporal, compositional, and functional interrogation of the gastrointestinal microbiota and its effects on the host physiology and disease phenotype. Classical, culture-based studies have documented that fecal microbial self-reinoculation (via coprophagy) affects the composition and abundance of microbes in the murine proximal gastrointestinal tract. This pervasive self-reinoculation behavior could be a particularly relevant study factor when investigating small intestine microbiota. Modern microbiome studies either do not take self-reinoculation into account, or assume that approaches such as single housing mice or housing on wire mesh floors eliminate it. These assumptions have not been rigorously tested with modern tools. Here, we used quantitative 16S rRNA gene amplicon sequencing, quantitative microbial functional gene content inference, and metabolomic analyses of bile acids to evaluate the effects of self-reinoculation on microbial loads, composition, and function in the murine upper gastrointestinal tract. RESULTS In coprophagic mice, continuous self-exposure to the fecal flora had substantial quantitative and qualitative effects on the upper gastrointestinal microbiome. These differences in microbial abundance and community composition were associated with an altered profile of the small intestine bile acid pool, and, importantly, could not be inferred from analyzing large intestine or stool samples. Overall, the patterns observed in the small intestine of non-coprophagic mice (reduced total microbial load, low abundance of anaerobic microbiota, and bile acids predominantly in the conjugated form) resemble those typically seen in the human small intestine. CONCLUSIONS Future studies need to take self-reinoculation into account when using mouse models to evaluate gastrointestinal microbial colonization and function in relation to xenobiotic transformation and pharmacokinetics or in the context of physiological states and diseases linked to small intestine microbiome and to small intestine dysbiosis. Video abstract.
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Affiliation(s)
- Said R Bogatyrev
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Justin C Rolando
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, USA
| | - Rustem F Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, USA.
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11
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Batani G, Bayer K, Böge J, Hentschel U, Thomas T. Fluorescence in situ hybridization (FISH) and cell sorting of living bacteria. Sci Rep 2019; 9:18618. [PMID: 31819112 PMCID: PMC6901588 DOI: 10.1038/s41598-019-55049-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 11/21/2019] [Indexed: 01/09/2023] Open
Abstract
Despite the development of several cultivation methods, the rate of discovery of microorganisms that are yet-to-be cultivated outpaces the rate of isolating and cultivating novel species in the laboratory. Furthermore, no current cultivation technique is capable of selectively isolating and cultivating specific bacterial taxa or phylogenetic groups independently of morphological or physiological properties. Here, we developed a new method to isolate living bacteria solely based on their 16S rRNA gene sequence. We showed that bacteria can survive a modified version of the standard fluorescence in situ hybridization (FISH) procedure, in which fixation is omitted and other factors, such as centrifugation and buffers, are optimized. We also demonstrated that labelled DNA probes can be introduced into living bacterial cells by means of chemical transformation and that specific hybridization occurs. This new method, which we call live-FISH, was then combined with fluorescence-activated cell sorting (FACS) to sort specific taxonomic groups of bacteria from a mock and natural bacterial communities and subsequently culture them. Live-FISH represents the first attempt to systematically optimize conditions known to affect cell viability during FISH and then to sort bacterial cells surviving the procedure. No sophisticated probe design is required, making live-FISH a straightforward method to be potentially used in combination with other single-cell techniques and for the isolation and cultivation of new microorganisms.
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Affiliation(s)
- Giampiero Batani
- Centre for Marine Science and Innovation and School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia
- Faculty of Science - Department of Parasitology, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Kristina Bayer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany
| | - Julia Böge
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany
| | - Ute Hentschel
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany
- Christian-Albrechts University of Kiel, Christian-Albrechts-Platz 4, 24118, Kiel, Germany
| | - Torsten Thomas
- Centre for Marine Science and Innovation and School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia.
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12
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Kan Y, Jiang N, Xu X, Lyu Q, Gopalakrishnan V, Walcott R, Burdman S, Li J, Luo L. Induction and Resuscitation of the Viable but Non-culturable (VBNC) State in Acidovorax citrulli, the Causal Agent of Bacterial Fruit Blotch of Cucurbitaceous Crops. Front Microbiol 2019; 10:1081. [PMID: 31156591 PMCID: PMC6529555 DOI: 10.3389/fmicb.2019.01081] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 04/29/2019] [Indexed: 01/14/2023] Open
Abstract
Acidovorax citrulli is a gram-negative bacterium that infects a wide range of cucurbits causing bacterial fruit blotch (BFB) disease. Copper-based compounds are the most widely-used chemicals for managing BFB and other bacterial diseases in the field. Many bacteria can enter a viable but non-culturable (VBNC) state in response to stress, including exposure to copper, and recover the culturability when favorable conditions return. The present study demonstrates that A. citrulli strain AAC00-1 is able to enter into the VBNC state by treatment with different concentrations of copper sulfate. It took 3 h, 5 and 15 days for all viable cells to lose culturability upon exposure to copper sulfate concentrations of 50, 10, and 5 μM, respectively. The VBNC A. citrulli cells regained culturability when the Cu2+ ions were removed by chelation with EDTA or by transfer of cells to LB broth, a cell-free supernatant from a suspension of AAC00-1, oligotrophic media amended with casein hydrolysate or watermelon seedling juice. We also found that the VBNC cells induced by Cu2+ were unable to colonize or infect watermelon seedlings directly, but the resuscitated cells recovered full virulence equivalent to untreated bacterial cells in the log phase. To the best of our knowledge, this is the first report on the VBNC state in A. citrulli and the factors that facilitate resuscitation and restoration of pathogenicity.
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Affiliation(s)
- Yumin Kan
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Na Jiang
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Xin Xu
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Qingyang Lyu
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Vinoj Gopalakrishnan
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Ronald Walcott
- Department of Plant Pathology, University of Georgia, Athens, GA, United States
| | - Saul Burdman
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Jianqiang Li
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Laixin Luo
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
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13
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Noviyanti F, Hosotani Y, Koseki S, Inatsu Y, Kawasaki S. Predictive Modeling for the Growth ofSalmonellaEnteritidis in Chicken Juice by Real-Time Polymerase Chain Reaction. Foodborne Pathog Dis 2018; 15:406-412. [DOI: 10.1089/fpd.2017.2392] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Fia Noviyanti
- Tsukuba Life Science Innovation, University of Tsukuba, Tsukuba, Japan
| | - Yukie Hosotani
- Division of Food Safety Research, Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Shigenobu Koseki
- Research Faculty of Agriculture, Hokkaido University, Hokkaido, Japan
| | - Yasuhiro Inatsu
- Division of Food Safety Research, Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Susumu Kawasaki
- Tsukuba Life Science Innovation, University of Tsukuba, Tsukuba, Japan
- Division of Food Safety Research, Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Japan
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14
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Pinto D, Santos MA, Chambel L. Thirty years of viable but nonculturable state research: unsolved molecular mechanisms. Crit Rev Microbiol 2013; 41:61-76. [PMID: 23848175 DOI: 10.3109/1040841x.2013.794127] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Viable but nonculturable (VBNC) cells were recognized 30 years ago; and despite decades of research on the topic, most results are disperse and apparently incongruous. Since its description, a huge controversy arose regarding the ecological significance of this state: is it a degradation process without real significance for bacterial life cycles or is it an adaptive strategy of bacteria to cope with stressful conditions? In order to solve the molecular mechanisms of VBNC state induction and resuscitation, researchers in the field must be aware and overcome common issues delaying research progress. In this review, we discuss the intrinsic characteristic features of VBNC cells, the first clues on what is behind the VBNC state's induction, the models proposed for their resuscitation and the current methods to prove not only that cells are in VBNC state but also that they are able to resuscitate.
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Affiliation(s)
- Daniela Pinto
- Center for Biodiversity, Functional and Integrative Genomics (BioFIG), Faculty of Sciences, University of Lisbon , Lisbon , Portugal
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15
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Agidi S, Vedachalam S, Mancl K, Lee J. Effectiveness of onsite wastewater reuse system in reducing bacterial contaminants measured with human-specific IMS/ATP and qPCR. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2013; 115:167-174. [PMID: 23254156 DOI: 10.1016/j.jenvman.2012.11.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 11/08/2012] [Accepted: 11/13/2012] [Indexed: 06/01/2023]
Abstract
Water shortages and the drive to recycle is increasing interest in reuse of reclaimed wastewater. Timely and cost-effective ways to detect fecal pollutants prior to reuse increases confidence of residents and neighbors concerned about reuse of reclaimed wastewater. The on-site wastewater treatment and reuse systems (OWTRS) used in this study include a septic tank, peat bioreactor, ClO(2) disinfection and land spray irrigation system. Bacteroides fragilis, Escherichia coli and Enterococcus spp., were tested with immunomagnetic separation/ATP bioluminescence (IMS/ATP), qPCR and culture-based methods. The results displayed a 2-log reduction in fecal bacteria in the peat bioreactor and a 5-log reduction following chloride dioxide disinfection. The fecal bacteria levels measured by IMS/ATP correlated with qPCR results: HuBac 16S (R(2) = 0.903), Bf-group 16S (R(2) = 0.956), gyrB (R(2) = 0.673), and Ent 23S (R(2) = 0.724). This is the first study in which the newly developed human-specific IMS/ATP and previously developed IMS/ATP were applied for determining OWTRS efficiency. Results of the study revealed that IMS/ATP is a timely and cost-effective way to detect fecal contaminants, and results were validated with qPCR and culture based methods. The new IMS/ATP can also be applied broadly in the detection of human-originated fecal contamination.
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Affiliation(s)
- Senyo Agidi
- College of Public Health, Division of Environmental Health Science, The Ohio State University, OH 43210, USA
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