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Kim SH, Lee JI, Kang DH. Effects of Na + adaptation on Bacillus cereus endospores inactivation and transcriptome changes. Food Res Int 2024; 195:114975. [PMID: 39277241 DOI: 10.1016/j.foodres.2024.114975] [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: 05/16/2024] [Revised: 08/20/2024] [Accepted: 08/20/2024] [Indexed: 09/17/2024]
Abstract
As Bacillus cereus endospores exist in various vegetables grown in soil, the possibility of contamination in food products with high salt concentrations cannot be ignored. Recent studies revealed that harsh conditions affect the resistance of bacteria; thus, we investigated the developmental aspect of heat resistance of B. cereus after sporulation with high NaCl concentration. RNA sequencing was conducted for transcriptomic changes when B. cereus endospores formed at high salinity, and membrane fluidity and hydrophobicity were measured to verify the transcriptomic analysis. Our data showed that increasing NaCl concentration in sporulation media led to a decrease in heat resistance. Also, endospore hydrophobicity, membrane fluidity, and endospore density decreased with sporulation at higher NaCl concentrations. When the transcript changes of B. cereus sporulated at NaCl concentrations of 0.5 and 7% were analyzed by transcriptome analysis, it was confirmed that the NaCl 7% endospores had significantly lower expression levels (FDR<0.05) of genes related to sporulation stages 3 and 4, which led to a decrease in expression of spore-related genes such as coat proteins and small acid-soluble proteins. Our findings indicated that high NaCl concentrations inhibited sporulation stages 3 and 4, thereby preventing proper cell maturation in the forespores and adequate formation of the coat protein and cortex. This inhibition led to decreased endospore density and hydrophobicity, ultimately resulting in reduced heat resistance.resistanceWe expect that this study will be utilized as a baseline for further studies and enhance sterilization strategies.
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Affiliation(s)
- Soo-Hwan Kim
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Jae-Ik Lee
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Dong-Hyun Kang
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do 25354, Republic of Korea.
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2
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Heckler C, Vale MG, Canales HDS, Stradiotto GC, Giordano ALPL, Schreiber AZ, Sant'Ana AS. Spore-forming bacteria in gelatin: Characterization, identification by 16S rRNA and MALDI-TOF mass spectrometry (MS), and presence of heat resistance and virulence genes. Int J Food Microbiol 2024; 422:110813. [PMID: 38970997 DOI: 10.1016/j.ijfoodmicro.2024.110813] [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: 02/05/2024] [Revised: 06/20/2024] [Accepted: 06/27/2024] [Indexed: 07/08/2024]
Abstract
Gelatin, a versatile protein derived from collagen, is widely used in the food, pharmaceutical and medical sectors. However, bacterial contamination by spore-forming bacteria during gelatin processing represents a significant concern for product safety and quality. In this study, an investigation was carried out to explore the heat and chemical resistance, as well as the identification and characterization of spore-forming bacteria isolated from gelatin processing. The methodologies involved chemical resistance tests with drastic pH in microplates and thermal resistance tests in capillary tubes of various isolates obtained at different processing stages. In addition, phenotypic and genotypic analyses were carried out to characterize the most resistant isolates of spore-forming bacteria. The findings of this study revealed the presence of several species, including Bacillus cereus, Bacillus licheniformis, Bacillus sonorensis, Bacillus subtilis, Geobacillus stearothermophilus, and Clostridium sporogenes, with some isolates exhibiting remarkable chemical and heat resistances. In addition, a significant proportion of the most resistant isolates showed gelatinase activity (n = 19/21; 90.5 %) and the presence of heat resistance (n = 5/21; 23.8 %), and virulence genes (n = 11/21; 52.4 %). The results of this study suggest that interventions should be done in quality control practices and that process parameter adjustments and effective contamination reduction strategies should be implemented through gelatin processing.
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Affiliation(s)
- Caroline Heckler
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Matheus G Vale
- Department of Integrated Systems, Faculty of Mechanical Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Héctor D S Canales
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Graziele C Stradiotto
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Ana Luisa P L Giordano
- Department of Clinical Pathology, Faculty of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil
| | - Angelica Z Schreiber
- Department of Clinical Pathology, Faculty of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil
| | - Anderson S Sant'Ana
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, São Paulo, Brazil.
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3
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Rolfe CA, Morrissey TR, Redan BW, Aguilar VL, Skinner GE, Reddy NR. Role of Dipicolinic Acid in Heat Resistance of Spores of Clostridium botulinum and Clostridium sporogenes PA3679 by Thermal and Pressure-assisted Thermal Processing. J Food Prot 2024; 87:100359. [PMID: 39260571 DOI: 10.1016/j.jfp.2024.100359] [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: 05/28/2024] [Revised: 08/06/2024] [Accepted: 09/05/2024] [Indexed: 09/13/2024]
Abstract
Dipicolinic acid (DPA) is a major constituent of spores and reportedly provides protection against inactivation by various thermal processes; however, the relationship between DPA and resistance towards pressure-assisted thermal processing is not well understood. Thermal and pressure-assisted thermal inactivation studies of Clostridium botulinum nonproteolytic strains QC-B and 610-F, proteolytic strain Giorgio-A, and thermal surrogate Clostridium sporogenes PA3679 spores suspended in ACES buffer (0.05 M, pH 7.0) were performed to determine if a relationship exists between DPA release and log reduction of spores. Thermal inactivation at 80, 83, and 87 °C for nonproteolytic strains and 101, 105, and 108 °C for the proteolytic strain and thermal surrogate were conducted. Pressure-assisted thermal inactivation for nonproteolytic strains at 83 °C/600 MPa and for the proteolytic strain and thermal surrogate at 105 °C/600 MPa were performed. Surviving spores were enumerated by 5-tube MPN method for log reductions and analyzed for released DPA by liquid chromatography-tandem mass spectrometry. The correlation between MPN log reductions, released DPA, and D-values were calculated. A positive correlation between released DPA and log reduction of spores was observed for QC-B and 610-F at 80 and 83 °C (r = 0.6073 - 0.7755; P < 0.01). At 87 °C, a positive correlation was detected for 610-F (r = 0.4242, P < 0.05) and no correlation was observed for QC-B (r = 0.1641; P > 0.05). A strong, positive correlation (r = 0.8359 - 0.9284; P < 0.05) between released DPA and log reduction of spores was observed for Giorgio-A at 101, 105, and 108 °C, and a strong, positive correlation (r = 0.8402; P < 0.05) was observed for PA3679 at 101 °C. A positive correlation (r = 0.5646 - 0.6724; P < 0.01) was observed for QC-B, 610-F, and Giorgio-A after pressure-assisted thermal treatment. No correlation (r = 02494; P > 0.05) was found for PA3679 after pressure-assisted thermal treatment. These results suggest a correlation exists between DPA release and heat resistance; however, the level of correlation varied between strains and temperatures. The findings from this research may aid in the development of spore inactivation strategies targeting the thermal resistance profiles of various strains of C. botulinum spores.
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Affiliation(s)
- Catherine A Rolfe
- U. S. Food and Drug Administration, Office of Food Safety, Division of Food Processing Science and Technology, Bedford Park, IL 60501, United States.
| | - Travis R Morrissey
- U. S. Food and Drug Administration, Office of Food Safety, Division of Food Processing Science and Technology, Bedford Park, IL 60501, United States
| | - Benjamin W Redan
- U. S. Food and Drug Administration, Office of Dietary Supplement Programs, Division of Policy and Regulation Implementation, College Park, MD 20740, United States; Food Process Evaluation Team, College Park, MD 20740, United States
| | - Viviana L Aguilar
- Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, IL 60501, United States
| | - Guy E Skinner
- U. S. Food and Drug Administration, Office of Food Safety, Multi-Component Foods, College Park, MD 20740, United States
| | - N Rukma Reddy
- U. S. Food and Drug Administration, Office of Food Safety, Division of Food Processing Science and Technology, Bedford Park, IL 60501, United States
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Lai Y, Jiang G, Liang T, Huang X, Jiang W, Xu W, Sun R, Dai Z, Li C. Rapid analysis of Bacillus cereus spore biomarkers based on porous channel cuttlebone SERS substrate. Anal Chim Acta 2024; 1320:343034. [PMID: 39142776 DOI: 10.1016/j.aca.2024.343034] [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: 05/10/2024] [Revised: 07/13/2024] [Accepted: 07/26/2024] [Indexed: 08/16/2024]
Abstract
BACKGROUND Bacillus cereus (B. cereus) is a widespread conditional pathogen that affects food safety and human health. Conventional methods such as bacteria culture and polymerase chain reaction (PCR) are difficult to use for rapid identification of bacterial spores because of the relatively long analysis times. From a human health perspective, there is an urgent need to develop an ultrasensitive, rapid, and accurate method for the detection of B. cereus spores. RESULTS The study proposed a new method for rapidly and sensitively detecting the biomarkers of bacterial spores via surface-enhanced Raman spectroscopy (SERS) combined with electrochemical enrichment. The 2,6-Pyridinedicarboxylic acid (DPA) was used as the model analyte to acts as a biomarker of B. cereus spores. The SERS substrate was developed via the in-situ generation of Ag nanoparticles (AgNPs) in a cuttlebone-derived organic matrix (CDOM). Because of the depletion of chitin reduction sites on the CDOM, the pores of the porous channels expanded. The pores diameter of the AgNPs/CDOM porous channel was found to be in the range of 0.7-1.3 nm through molecular diffusion experiments. Based on the porosity of AgNPs/CDOM substrates and the high sensitivity of SERS substrates, the sensor can rapidly and accurately electronically enrich DPA in 40 s with the limit of detection (LOD) of 0.3 nM. SIGNIFICANCE The results demonstrate that electrochemically assisted SERS substrates can be served as a high sensitivity electrochemical-enrichment device for the rapid and sensitive detection of bacterial spores with minimal interference from potentially coexisting species in biological samples. In this study, it opens up a platform to explore the application of porous channels in natural bio-derived materials in the field of food safety.
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Affiliation(s)
- Yuping Lai
- School of Chemistry and Environment, Guangdong Ocean University, Analytical and Testing Center of Guangdong Ocean University, Guangdong Provincial Key Laboratory of Intelligent Equipment for South China Sea Marine Ranching, Zhanjiang, 524088, China
| | - Guangzheng Jiang
- Guangxi Engineering Research Center of Processing & Storage of Characteristic and Advantage Aquatic Products, Guangxi Academy of Fishery Sciences, Nanning, 530021, China
| | - Tianhang Liang
- School of Chemistry and Environment, Guangdong Ocean University, Analytical and Testing Center of Guangdong Ocean University, Guangdong Provincial Key Laboratory of Intelligent Equipment for South China Sea Marine Ranching, Zhanjiang, 524088, China
| | - Xiaoxin Huang
- School of Chemistry and Environment, Guangdong Ocean University, Analytical and Testing Center of Guangdong Ocean University, Guangdong Provincial Key Laboratory of Intelligent Equipment for South China Sea Marine Ranching, Zhanjiang, 524088, China
| | - Wanjun Jiang
- The North China Sea Area & Island Center, Ministry of Natural Resources, Qingdao, 266061, China.
| | - Wenhui Xu
- School of Chemistry and Environment, Guangdong Ocean University, Analytical and Testing Center of Guangdong Ocean University, Guangdong Provincial Key Laboratory of Intelligent Equipment for South China Sea Marine Ranching, Zhanjiang, 524088, China
| | - Ruikun Sun
- School of Chemistry and Environment, Guangdong Ocean University, Analytical and Testing Center of Guangdong Ocean University, Guangdong Provincial Key Laboratory of Intelligent Equipment for South China Sea Marine Ranching, Zhanjiang, 524088, China; Shenzhen Institute of Guangdong Ocean University, Shenzhen, 518108, China
| | - Zhenqing Dai
- School of Chemistry and Environment, Guangdong Ocean University, Analytical and Testing Center of Guangdong Ocean University, Guangdong Provincial Key Laboratory of Intelligent Equipment for South China Sea Marine Ranching, Zhanjiang, 524088, China; Shenzhen Institute of Guangdong Ocean University, Shenzhen, 518108, China.
| | - Chengyong Li
- School of Chemistry and Environment, Guangdong Ocean University, Analytical and Testing Center of Guangdong Ocean University, Guangdong Provincial Key Laboratory of Intelligent Equipment for South China Sea Marine Ranching, Zhanjiang, 524088, China; Shenzhen Institute of Guangdong Ocean University, Shenzhen, 518108, China.
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5
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Khanal S, Kim TD, Begyn K, Duverger W, Kramer G, Brul S, Rajkovic A, Devlieghere F, Heyndrickx M, Schymkowitz J, Rousseau F, Broussolle V, Michiels C, Aertsen A. Mechanistic insights into the adaptive evolvability of spore heat resistance in Bacillus cereus sensu lato. Int J Food Microbiol 2024; 418:110709. [PMID: 38663147 DOI: 10.1016/j.ijfoodmicro.2024.110709] [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: 10/18/2023] [Revised: 03/09/2024] [Accepted: 04/13/2024] [Indexed: 05/27/2024]
Abstract
Wet heat treatment is a commonly applied method in the food and medical industries for the inactivation of microorganisms, and bacterial spores in particular. While many studies have delved into the mechanisms underlying wet heat killing and spore resistance, little attention has so far been dedicated to the capacity of spore-forming bacteria to tune their resistance through adaptive evolution. Nevertheless, a recent study from our group revealed that a psychrotrophic strain of the Bacillus cereus sensu lato group (i.e. Bacillus weihenstephanensis LMG 18989) could readily and reproducibly evolve to acquire enhanced spore wet heat resistance without compromising its vegetative cell growth ability at low temperatures. In the current study, we demonstrate that another B. cereus strain (i.e. the mesophilic B. cereus sensu stricto ATCC 14579) can acquire significantly increased spore wet heat resistance as well, and we subjected both the previously and currently obtained mutants to whole genome sequencing. This revealed that five out of six mutants were affected in genes encoding regulators of the spore coat and exosporium pathway (i.e. spoIVFB, sigK and gerE), with three of them being affected in gerE. A synthetically constructed ATCC 14579 ΔgerE mutant likewise yielded spores with increased wet heat resistance, and incurred a compromised spore coat and exosporium. Further investigation revealed significantly increased spore DPA levels and core dehydration as the likely causes for the observed enhanced spore wet heat resistance. Interestingly, deletion of gerE in Bacillus subtilis 168 did not impose increased spore wet heat resistance, underscoring potentially different adaptive evolutionary paths in B. cereus and B. subtilis.
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Affiliation(s)
- Sadhana Khanal
- Laboratory of Food Microbiology, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
| | - Tom Dongmin Kim
- Laboratory of Food Microbiology, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
| | - Katrien Begyn
- Research Unit Food Microbiology and Food Preservation (FMFP-UGent), Department of Food Technology, Safety and Health, Part of Food2Know, Faculty Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Wouter Duverger
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | - Gertjan Kramer
- Laboratory for Mass Spectrometry of Biomolecules, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098XH Amsterdam, the Netherlands
| | - Stanley Brul
- Molecular Biology & Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098XH Amsterdam, the Netherlands
| | - Andreja Rajkovic
- Research Unit Food Microbiology and Food Preservation (FMFP-UGent), Department of Food Technology, Safety and Health, Part of Food2Know, Faculty Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Frank Devlieghere
- Research Unit Food Microbiology and Food Preservation (FMFP-UGent), Department of Food Technology, Safety and Health, Part of Food2Know, Faculty Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Marc Heyndrickx
- ILVO - Flanders Research Institute for Agriculture, Fisheries and Food, Technology and Food Science, Unit - Food Safety, Melle, Belgium; Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | - Frederic Rousseau
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | | | - Chris Michiels
- Laboratory of Food Microbiology, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
| | - Abram Aertsen
- Laboratory of Food Microbiology, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium..
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Chincha AAIA, Marone MP, Pia AKR, Freire L, Amorim-Neto DP, Carazzolle MF, Sant'Ana AS. Phenotypic, genotypic, and resistome of mesophilic spore-forming bacteria isolated from pasteurized liquid whole egg. Food Res Int 2024; 184:114215. [PMID: 38609213 DOI: 10.1016/j.foodres.2024.114215] [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: 10/17/2023] [Revised: 02/22/2024] [Accepted: 03/06/2024] [Indexed: 04/14/2024]
Abstract
The production of whole-liquid eggs is of significant economic and nutritional importance. This study aimed to assess the phenotypic and genotypic diversity of mesophilic aerobic spore-forming bacteria (n = 200) isolated from pasteurized whole liquid egg and liquid egg yolk. The majority of the isolates were identified as belonging to the genera Bacillus (86 %), followed by Brevibacillus (10 %) and Lysinibacillus (4 %). For the phenotypic characterization, isolates were subjected to various heat shocks, with the most significant reductions observed at 80 °C/30 min and 90 °C/10 min for isolates recovered from raw materials. On the other hand, the decrease was similar for isolates recovered from raw material and final product at 100 °C/5 min and 110 °C/5 min. Genotypic genes related to heat resistance (cdnL, spoVAD, dacB, clpC, dnaK, and yitF/Tn1546) were examined for genotypic characterization. The dnaK gene showed a positive correlation with the highest thermal condition tested (110 °C/5 min), while 100 °C/5 min had the highest number of positively correlated genes (clpC, cdnL, yitF/Tn1546, and spoVAD). Whole Genome Sequencing of four strains revealed genes related to sporulation, structure formation, initiation and regulation, stress response, and DNA repair in vegetative cells. The findings of this study indicate that these mesophilic aerobic spore-forming bacteria may adopt several strategies to persist through the process and reach the final product. As the inactivation of these microorganisms during egg processing is challenging, preventing raw materials contamination and their establishment in processing premises must be reinforced.
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Affiliation(s)
- Alexandra A I A Chincha
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Marina P Marone
- Laboratory of Genomics and BioEnergy, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas, Campinas, SP, Brazil
| | - Arthur K R Pia
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Luisa Freire
- Faculty of Pharmaceutical Sciences, Food and Nutrition, Federal University of Mato Grosso do Sul. Campo Grande, Mato Grosso do Sul, Brazil
| | - Dionisio P Amorim-Neto
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Marcelo F Carazzolle
- Laboratory of Genomics and BioEnergy, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas, Campinas, SP, Brazil; Center for Computing and Engineering Sciences, University of Campinas, Campinas, SP, Brazil
| | - Anderson S Sant'Ana
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil.
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Cao R, Tan L, Wan Q, Wu G, Wang J, Lin Y, Huang T, Wen G. The improved resistance of germinated spores to ultraviolet irradiation: Comparison with chlorine. CHEMOSPHERE 2024; 349:140929. [PMID: 38092169 DOI: 10.1016/j.chemosphere.2023.140929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/07/2023] [Accepted: 12/07/2023] [Indexed: 12/19/2023]
Abstract
Fungi outbreaks in water will include a series of processes, including spore aggregation, germination, biofilm, and finally present in a mixed state in the aquatic environment. More attention is paid to the control of dispersed fungal spores, however, there was little knowledge of the control of germinated spores. This study investigated the inactivation kinetics and mechanism of ultraviolet (UV) treatment for fungal spores with different germination percentages compared with dormant spores. The results indicated that the inactivation rate constants (k) of spores with 5%-45% germination were 0.0278-0.0299 cm2/mJ for Aspergillus niger and 0.0588-0.0647 cm2/mJ for Penicillium polonicum, which were lower than those of dormant spores. It suggested that germinated spores were more tolerant to UV irradiation than dormant spores, and it may be due to the defensive barrier (upregulated pigments) and some reductive substance (upregulated enoyl reductase) by absorbing UV or reacting with reactive oxygen species according to transcriptome analysis. Compared to dormant spores, the k-UV of germinated spores decreased by 18.17%-26.56% for Aspergillus niger, which was less than k-chlorine (62.33%-69.74%). A slighter decrease in k-UV showed UV irradiation can efficiently control fungi contamination, especially when dormant spores and germinated spores coexisted in actual water systems. This study indicates that more attention should be paid to germinated spores.
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Affiliation(s)
- Ruihua Cao
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China
| | - Lili Tan
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China
| | - Qiqi Wan
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China
| | - Gehui Wu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China
| | - Jingyi Wang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China
| | - Yingzi Lin
- School of Municipal and Environmental Engineering, Jilin Jianzhu University, Changchun 130118, PR China
| | - Tinglin Huang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China
| | - Gang Wen
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China.
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8
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Juneja VK, Osoria M, Altuntas EG, Taneja NK, Thakur S, Kumar GD, Setlow P. Effects of spore purity on the wet heat resistance of Clostridium perfringens, Bacillus cereus and Bacillus subtilis spores. Food Res Int 2024; 177:113904. [PMID: 38225145 DOI: 10.1016/j.foodres.2023.113904] [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: 10/19/2023] [Revised: 12/13/2023] [Accepted: 12/21/2023] [Indexed: 01/17/2024]
Abstract
Heat resistance of spores of Clostridium perfringens 8238 (Hobbs Serotype 2), Bacillus cereus NCTC 11143 (4810/72), and Bacillus subtilis PS533, an isogenic derivative of strain PS832 (a 168 strain) was determined in ground beef at 95 °C. Spore purification was by centrifugation and washing with sterile distilled water (dH2O), followed by sonication and then Histodenz centrifugation for B. subtilis and C. perfringens, and centrifugation and washing with sterile dH2O followed by Histodenz centrifugation for B. cereus. Bags containing inoculated beef samples were submerged in a temperature-controlled water bath and held at 95 °C for predetermined lengths of time. Surviving spore populations were enumerated by plating on mannitol egg yolk polymyxin agar (MYP) agar plates for B. cereus and B. subtilis, and on tryptose-sulfite-cycloserine agar (TSC) agar plates for C. perfringens. Survivor curves were fitted to linear, linear with tail, and Weibull models using the USDA Integrated Pathogen Modeling Program (IPMP) 2013 software. The Weibull model provided a relatively better fit to the data since the root mean square error (RMSE), mean square error (MSE), sum of squared errors (SSE), and Akaike information criterion (AIC) values were lower than the values obtained using the linear or the linear with tail models. Additionally, the Weibull model accurately predicted the observed D-values at 95 °C for the three spore-formers since the accuracy factor (Af) values ranged from 1.03 to 1.08 and the bias factor (Bf) values were either 1.00 or 1.01. Times at 95 °C to achieve a 3-log reduction decreased from 206 min for C. perfringens spores purified with water washes alone to 191 min with water washes followed by sonication and Histodenz centrifugation, from 7.9 min for B. cereus spores purified with water washes alone to 1.4 min with water washes followed by Histodenz centrifugation, and from 20.6 min for B. subtilis spores purified with water washes alone to 6.7 min for water washes followed by sonication and Histodenz centrifugation. Thermal-death-time values reported in this study will assist food processors to design thermal processes to guard against bacterial spores in cooked foods. In addition, clearly spore purity is an additional factor in spore wet heat resistance, although the cause of this effect is not clear.
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Affiliation(s)
- Vijay K Juneja
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
| | - Marangeli Osoria
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA
| | | | - Neetu K Taneja
- Department of Basics and Applied Sciences, NIFTEM, Sonipat 131028, Haryana, India
| | - Sheetal Thakur
- University Centre for Research & Development, UIBT, Chandigarh University, Gharuan-Mohali, Punjab, India
| | - Govindaraj D Kumar
- Center for Food Safety, College of Agriculture and Environmental Sciences, The University of Georgia, Griffin Campus, GA, USA
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06030-3305, USA
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9
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Smita N, Sasikala C, Ramana C. New insights into peroxide toxicology: sporulenes help Bacillus subtilis endospores from hydrogen peroxide. J Appl Microbiol 2023; 134:lxad238. [PMID: 37863832 DOI: 10.1093/jambio/lxad238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/11/2023] [Accepted: 10/19/2023] [Indexed: 10/22/2023]
Abstract
AIM The purpose of the present study was to understand the possible events involved in the toxicity of hydrogen peroxide (H2O2) to wild and sporulene-deficient spores of Bacillus subtilis, as H2O2 was previously shown to have deleterious effects. METHODS AND RESULTS The investigation utilized two strains of B. subtilis, namely the wild-type PY79 (WT) and the sporulene-deficient TB10 (ΔsqhC mutant). Following treatment with 0.05% H2O2 (v/v), spore viability was assessed using a plate count assay, which revealed a significant decrease in cultivability of 80% for the ΔsqhC mutant spores. Possible reasons for the loss of spore viability were investigated with microscopic analysis, dipicholinic acid (DPA) quantification and propidium iodide (PI) staining. Microscopic examinations revealed the presence of withered and deflated morphologies in spores of ΔsqhC mutants treated with H2O2, indicating a compromised membrane permeability. This was further substantiated by the absence of DPA and a high frequency (50%-75%) of PI infiltration. The results of fatty acid methyl ester analysis and protein profiling indicated that the potentiation of H2O2-induced cellular responses was manifested in the form of altered spore composition in ΔsqhC B. subtilis. The slowed growth rates of the ΔsqhC mutant and the heightened sporulene biosynthesis pathways in the WT strain, both upon exposure to H2O2, suggested a protective function for sporulenes in vegetative cells. CONCLUSIONS Sporulenes serve as a protective layer for the inner membrane of spores, thus assuming a significant role in mitigating the adverse effects of H2O2 in WT B. subtilis. The toxic effects of H2O2 were even more pronounced in the spores of the ΔsqhC mutant, which lacks this protective barrier of sporulenes.
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Affiliation(s)
- N Smita
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad 500046, India
| | - Ch Sasikala
- Bacterial Discovery Laboratory, Centre for Environment, Institute of Science and Technology, J.N.T. University Hyderabad, Hyderabad 500085, India
| | - ChV Ramana
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad 500046, India
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10
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Li YQ, He L, Aryal M, Wicander J, Korza G, Setlow P. Thioflavin-T does not report on electrochemical potential and memory of dormant or germinating bacterial spores. mBio 2023; 14:e0222023. [PMID: 37830807 PMCID: PMC10653816 DOI: 10.1128/mbio.02220-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 08/24/2023] [Indexed: 10/14/2023] Open
Abstract
IMPORTANCE Bacillus and Clostridium spores cause food spoilage and disease because of spores' dormancy and resistance to microbicides. However, when spores "come back to life" in germination, their resistance properties are lost. Thus, understanding the mechanisms of spore germination could facilitate the development of "germinate to eradicate" strategies. One germination feature is the memory of a pulsed germinant stimulus leading to greater germination following a second pulse. Recent observations of increases in spore binding of the potentiometric dye thioflavin-T early in their germination of spores led to the suggestion that increasing electrochemical potential is how spores "remember" germinant pulses. However, new work finds no increased thioflavin-T binding in the physiological germination of Coatless spores or of intact spores germinating with dodecylamine, even though spore memory is seen in both cases. Thus, using thioflavin-T uptake by germinating spores to assess the involvement of electrochemical potential in memory of germinant exposure, as suggested recently, is questionable.
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Affiliation(s)
- Yong-qing Li
- School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan, Guangdong, China
- Department of Physics, East Carolina University, Greenville, North Carolina, USA
| | - Lin He
- School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan, Guangdong, China
| | - Makunda Aryal
- Department of Physics, East Carolina University, Greenville, North Carolina, USA
| | - James Wicander
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - George Korza
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
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11
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Ribis JW, Melo L, Shrestha S, Giacalone D, Rodriguez EE, Shen A, Rohlfing A. Single-spore germination analyses reveal that calcium released during Clostridioides difficile germination functions in a feedforward loop. mSphere 2023; 8:e0000523. [PMID: 37338207 PMCID: PMC10449524 DOI: 10.1128/msphere.00005-23] [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: 01/18/2023] [Accepted: 04/21/2023] [Indexed: 06/21/2023] Open
Abstract
Clostridioides difficile infections begin when its metabolically dormant spores germinate in response to sensing bile acid germinants alongside amino acid and divalent cation co-germinants in the small intestine. While bile acid germinants are essential for C. difficile spore germination, it is currently unclear whether both co-germinant signals are required. One model proposes that divalent cations, particularly Ca2+, are essential for inducing germination, while another proposes that either co-germinant class can induce germination. The former model is based on the finding that spores defective in releasing large stores of internal Ca2+ in the form of calcium dipicolinic acid (CaDPA) cannot germinate when germination is induced with bile acid germinant and amino acid co-germinant alone. However, since the reduced optical density of CaDPA-less spores makes it difficult to accurately measure their germination, we developed a novel automated, time-lapse microscopy-based germination assay to analyze CaDPA mutant germination at the single-spore level. Using this assay, we found that CaDPA mutant spores germinate in the presence of amino acid co-germinant and bile acid germinant. Higher levels of amino acid co-germinants are nevertheless required to induce CaDPA mutant spores to germinate relative to WT spores because CaDPA released by WT spores during germination can function in a feedforward loop to potentiate the germination of other spores within the population. Collectively, these data indicate that Ca2+ is not essential for inducing C. difficile spore germination because amino acid and Ca2+ co-germinant signals are sensed by parallel signaling pathways. IMPORTANCE Clostridioides difficile spore germination is essential for this major nosocomial pathogen to initiate infection. C. difficile spores germinate in response to sensing bile acid germinant signals alongside co-germinant signals. There are two classes of co-germinant signals: Ca2+ and amino acids. Prior work suggested that Ca2+ is essential for C. difficile spore germination based on bulk population analyses of germinating CaDPA mutant spores. Since these assays rely on optical density to measure spore germination and the optical density of CaDPA mutant spores is reduced relative to WT spores, this bulk assay is limited in its capacity to analyze germination. To overcome this limitation, we developed an automated image analysis pipeline to monitor C. difficile spore germination using time-lapse microscopy. With this analysis pipeline, we demonstrate that, although Ca2+ is dispensable for inducing C. difficile spore germination, CaDPA can function in a feedforward loop to potentiate the germination of neighboring spores.
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Affiliation(s)
- John W. Ribis
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Luana Melo
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Shailab Shrestha
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - David Giacalone
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | | | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Amy Rohlfing
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts University, Boston, Massachusetts, USA
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12
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Setlow P, Christie G. New Thoughts on an Old Topic: Secrets of Bacterial Spore Resistance Slowly Being Revealed. Microbiol Mol Biol Rev 2023; 87:e0008022. [PMID: 36927044 PMCID: PMC10304885 DOI: 10.1128/mmbr.00080-22] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023] Open
Abstract
The quest for bacterial survival is exemplified by spores formed by some Firmicutes members. They turn up everywhere one looks, and their ubiquity reflects adaptations to the stresses bacteria face. Spores are impactful in public health, food safety, and biowarfare. Heat resistance is the hallmark of spores and is countered principally by a mineralized gel-like protoplast, termed the spore core, with reduced water which minimizes macromolecular movement/denaturation/aggregation. Dry heat, however, introduces mutations into spore DNA. Spores have countermeasures to extreme conditions that are multifactorial, but the fact that spore DNA is in a crystalline-like nucleoid in the spore core, likely due to DNA saturation with small acid-soluble spore proteins (SASPs), suggests that reduced macromolecular motion is also critical in spore dry heat resistance. SASPs are also central in the radiation resistance characteristic of spores, where the contributions of four spore features-SASP; Ca2+, with pyridine-2,6-dicarboxylic acid (CaDPA); photoproduct lyase; and low water content-minimize DNA damage. Notably, the spore environment steers UV photochemistry toward a product that germinated spores can repair without significant mutagenesis. This resistance extends to chemicals and macromolecules that could damage spores. Macromolecules are excluded by the spore coat which impedes the passage of moieties of ≥10 kDa. Additionally, damaging chemicals may be degraded or neutralized by coat enzymes/proteins. However, the principal protective mechanism here is the inner membrane, a compressed structure lacking lipid fluidity and presenting a barrier to the diffusion of chemicals into the spore core; SASP saturation of DNA also protects against genotoxic chemicals. Spores are also resistant to other stresses, including high pressure and abrasion. Regardless, overarching mechanisms associated with resistance seem to revolve around reduced molecular motion, a fine balance between rigidity and flexibility, and perhaps efficient repair.
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Affiliation(s)
- Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Graham Christie
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
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13
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Pu S, Shi C, Lv C, Xu K, Hou X, Wu L. Tb 3+-Based Off-On Fluorescent Platform for Multicolor and Dosage-Sensitive Visualization of Bacterial Spore Marker. Anal Chem 2023; 95:8137-8144. [PMID: 37167590 DOI: 10.1021/acs.analchem.3c01542] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Developing a novel strategy for the sensitive and rapid detection of pathogenic bacterial spores in field or on-site settings will be helpful in minimizing their potential threats to human health, environmental safety, and food safety. In this study, Tb3+ was combined with glutathione (GSH)-modified copper nanoclusters (CuNCs), and an aggregation-induced emission (AIE) fluorescent probe based on Tb-GSH-CuNCs was fabricated for dipicolinic acid (DPA, a pathogenic bacterial spore marker) sensing. Making use of the competitive binding of Tb3+ between GSH-CuNCs and DPA, a multicolor sensing of DPA was facilely realized without introducing fluorescent materials as the reference. Due to an "off-on" response mechanism of the AIE fluorescent probe, this multicolor response to DPA exhibited a feature of rich color gradients and highly discriminative color change, allowing a dosage-sensitive visual quantification of DPA. The DPA with a concentration even as low as 0.5 μM can still be identified by the naked eye. Moreover, together with a smartphone app, which can extract the R (red), G (green), and B (blue) values from the probe system, a portable platform can be established for sensitive DPA quantification in the range of 0.5-70 μM, showing great potential for the practical monitoring of DPA in field or on-site settings.
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Affiliation(s)
- Shan Pu
- Analytical & Testing Center, Sichuan University, Chengdu, Sichuan 610064, P. R. China
| | - Chaoting Shi
- Analytical & Testing Center, Sichuan University, Chengdu, Sichuan 610064, P. R. China
| | - Caizhi Lv
- Analytical & Testing Center, Sichuan University, Chengdu, Sichuan 610064, P. R. China
| | - Kailai Xu
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, P. R. China
| | - Xiandeng Hou
- Analytical & Testing Center, Sichuan University, Chengdu, Sichuan 610064, P. R. China
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, P. R. China
| | - Lan Wu
- Analytical & Testing Center, Sichuan University, Chengdu, Sichuan 610064, P. R. China
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14
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Tanaka K, Oketani R, Terada T, Leproux P, Morono Y, Kano H. Label-Free Identification of Spore-Forming Bacteria Using Ultrabroadband Multiplex Coherent Anti-Stokes Raman Scattering Microspectroscopy. J Phys Chem B 2023; 127:1940-1946. [PMID: 36821702 DOI: 10.1021/acs.jpcb.2c07291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Spore-forming bacteria accumulate dipicolinic acid (DPA) to form spores to survive in extreme environments. Vibrational spectroscopy is widely used to detect DPA and elucidate the existence of the bacteria, while vegetative cells, another form of spore-forming bacteria, have not been studied extensively. Herein, we applied coherent anti-Stokes Raman scattering (CARS) microscopy to spectroscopically identify both spores and vegetative cells without staining or molecular tagging. The spores were identified by the strong CARS signals due to DPA. Furthermore, we observed bright spots in the vegetative cells in the CARS image at 1735 cm-1. The vegetative cells contained molecular species with C=O bonds because this vibrational mode was associated with the carbonyl group. One of the candidate molecular species is diketopimelic acid (DKP), a DPA precursor. This hypothesis was verified by comparing the spectrum obtained by the vegetative cells with that of the DKP analogue (ketopimelic acid) and with the result obtained by DFT calculation. The results indicate that the observed vegetative cell is in the sporulation process. CARS spectra can be used to monitor the maturation and preformation of spores.
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Affiliation(s)
- Kyosuke Tanaka
- Department of Chemistry, Faculty of Science, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ryosuke Oketani
- Department of Chemistry, Faculty of Science, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Takeshi Terada
- Marine Works Japan, 3-54-1 Oppamahigashi, Yokosuka, Kanagawa 237-0063, Japan
| | - Philippe Leproux
- Institut de Recherche XLIM, UMR CNRS No. 7252, 123 Avenue Albert Thomas, 87060 Limoges CEDEX, France
| | - Yuki Morono
- Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 200 Monobe Otsu, Nankoku City, Kochi 783-8502, Japan
| | - Hideaki Kano
- Department of Chemistry, Faculty of Science, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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15
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Ayerakwa EA, Abban MK, Isawumi A, Mosi L. Profiling Mycobacterium ulcerans: sporulation, survival strategy and response to environmental factors. Future Sci OA 2023; 9:FSO845. [PMID: 37026027 PMCID: PMC10072065 DOI: 10.2144/fsoa-2022-0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 03/07/2023] [Indexed: 04/03/2023] Open
Abstract
Mycobacterium ulcerans is the causative agent of Buruli ulcer – a necrotizing skin infection. As an environmental pathogen, it has developed stress response mechanisms for survival. Similar to endospore formation in M. marinum, it is likely that M. ulcerans employs sporulation mechanisms for its survival and transmission. In this review, we modeled possible transmission routes and patterns of M. ulcerans from the environment to its host. We provided insights into the evolution of M. ulcerans and its genomic profiles. We discuss reservoirs of M. ulcerans as an environmental pathogen and its environmental survival. We comprehensively discuss sporulation as a possible stress response mechanism and modelled endospore formation in M. ulcerans. At last, we highlighted sporulation associated markers, which upon expression trigger endospore formation.
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16
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Korza G, DePratti S, Fairchild D, Wicander J, Kanaan J, Shames H, Nichols FC, Cowan A, Brul S, Setlow P. Expression of the 2Duf protein in wild-type Bacillus subtilis spores stabilizes inner membrane proteins and increases spore resistance to wet heat and hydrogen peroxide. J Appl Microbiol 2023; 134:lxad040. [PMID: 36841229 PMCID: PMC10035073 DOI: 10.1093/jambio/lxad040] [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: 12/05/2022] [Revised: 02/09/2023] [Accepted: 02/24/2023] [Indexed: 02/27/2023]
Abstract
AIMS This work aimed to characterize spore inner membrane (IM) properties and the mechanism of spore killing by wet heat and H2O2 with spores overexpressing the 2Duf protein, which is naturally encoded from a transposon found only in some Bacillus strains with much higher spore resistance than wild-type spores. METHODS AND RESULTS Killing of Bacillus subtilis spores by wet heat or hydrogen peroxide (H2O2) was slower when 2Duf was present, and Ca-dipicolinic acid release was slower than killing. Viabilities on rich plates of wet heat- or H2O2 -treated spores +/- 2Duf were lower when NaCl was added, but higher with glucose. Addition of glucose but not Casamino acids addition increased treated spores' viability on minimal medium plates. Spores with 2Duf required higher heat activation for germination, and their germination was more wet-heat resistant than that of wild-type spores, processes that involve IM proteins. IM permeability and lipid mobility were lower in spores with 2Duf, although IM phospholipid composition was similar in spores +/- 2Duf. CONCLUSIONS These results and previous work suggests that wet heat and H2O2 kill spores by damaging an IM enzyme or enzymes involved in oxidative phosphorylation.
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Affiliation(s)
- George Korza
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Sarah DePratti
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Daniel Fairchild
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - James Wicander
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Julia Kanaan
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Hannah Shames
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Frank C Nichols
- Division of Periodontology, UConn Health, Farmington, CT 06030-3305, USA
| | - Ann Cowan
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Stanley Brul
- Molecular Biology & Microbial Food Safety, Swammerdam Institute for Life Science, University of Amsterdam, 1098XH Amsterdam, UK
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
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17
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Korza G, Goulet M, DeMarco A, Wicander J, Setlow P. Role of Bacillus subtilis Spore Core Water Content and pH in the Accumulation and Utilization of Spores' Large 3-Phosphoglyceric Acid Depot, and the Crucial Role of This Depot in Generating ATP Early during Spore Germination. Microorganisms 2023; 11:microorganisms11010195. [PMID: 36677488 PMCID: PMC9864370 DOI: 10.3390/microorganisms11010195] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/03/2023] [Accepted: 01/10/2023] [Indexed: 01/13/2023] Open
Abstract
The development of Bacillus spore cores involves the accumulation of 3-phosphoglycerate (3PGA) during sporulation, following core acidification to ~6.4, and before decreases in core water content occur due to Ca-dipicolinc acid (CaDPA) uptake. This core acidification inhibits phosphoglycerate mutase (PGM) at pH 6.4, allowing 3PGA accumulation, although PGM is active at pH 7.4. Spores’ 3PGA is stable for months at 4 °C and weeks at 37 °C. However, in wild-type spore germination, increases in core pH to 7.5−8 and in core water content upon CaDPA release and cortex peptidoglycan hydrolysis allow for rapid 3PGA catabolism, generating ATP; indeed, the earliest ATP generated following germination is from 3PGA catabolism. The current work found no 3PGA in those Bacillus subtilis spores that do not accumulate CaDPA during sporulation and have a core pH of ~7.4. The ATP production in the germination of 3PGA-less spores in a poor medium was minimal, and the germinated spores were >99% dead. However, the 3PGA-replete spores that germinated in the poor medium accumulated >30 times more ATP, and >70% of the germinated spores were found to be alive. These findings indicate why 3PGA accumulation during sporulation (and utilization during germination) in all the Firmicute spores studied can be crucial for spore revival due to the generation of essential ATP. The latter finding further suggests that targeting PGM activity during germination could be a novel way to minimize the damaging effects of spores.
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18
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Yu B, Kanaan J, Shames H, Wicander J, Aryal M, Li Y, Korza G, Brul S, Kramer G, Li YQ, Nichols FC, Hao B, Setlow P. Identification and characterization of new proteins crucial for bacterial spore resistance and germination. Front Microbiol 2023; 14:1161604. [PMID: 37113233 PMCID: PMC10126465 DOI: 10.3389/fmicb.2023.1161604] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 03/17/2023] [Indexed: 04/29/2023] Open
Abstract
2Duf, named after the presence of a transmembrane (TM) Duf421 domain and a small Duf1657 domain in its sequence, is likely located in the inner membrane (IM) of spores in some Bacillus species carrying a transposon with an operon termed spoVA 2mob. These spores are known for their extreme resistance to wet heat, and 2Duf is believed to be the primary contributor to this trait. In this study, we found that the absence of YetF or YdfS, both Duf421 domain-containing proteins and found only in wild-type (wt) B. subtilis spores with YetF more abundant, leads to decreased resistance to wet heat and agents that can damage spore core components. The IM phospholipid compositions and core water and calcium-dipicolinic acid levels of YetF-deficient spores are similar to those of wt spores, but the deficiency could be restored by ectopic insertion of yetF, and overexpression of YetF increased wt spore resistance to wet heat. In addition, yetF and ydfS spores have decreased germination rates as individuals and populations with germinant receptor-dependent germinants and increased sensitivity to wet heat during germination, potentially due to damage to IM proteins. These data are consistent with a model in which YetF, YdfS and their homologs modify IM structure to reduce IM permeability and stabilize IM proteins against wet heat damage. Multiple yetF homologs are also present in other spore forming Bacilli and Clostridia, and even some asporogenous Firmicutes, but fewer in asporogenous species. The crystal structure of a YetF tetramer lacking the TM helices has been reported and features two distinct globular subdomains in each monomer. Sequence alignment and structure prediction suggest this fold is likely shared by other Duf421-containing proteins, including 2Duf. We have also identified naturally occurring 2duf homologs in some Bacilli and Clostridia species and in wt Bacillus cereus spores, but not in wt B. subtilis. Notably, the genomic organization around the 2duf gene in most of these species is similar to that in spoVA 2mob, suggesting that one of these species was the source of the genes on this operon in the extremely wet heat resistant spore formers.
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Affiliation(s)
- Benjamin Yu
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Julia Kanaan
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Hannah Shames
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - James Wicander
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Makunda Aryal
- Department of Physics, East Carolina University, Greenville, NC, United States
| | - Yunfeng Li
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - George Korza
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Stanley Brul
- Molecular Biology and Microbial Food Safety, University of Amsterdam, Amsterdam, Netherlands
| | - Gertjan Kramer
- Laboratory for Mass Spectrometry of Biomolecules, Swammerdam Institute for Life Science, University of Amsterdam, Amsterdam, Netherlands
| | - Yong-qing Li
- Department of Physics, East Carolina University, Greenville, NC, United States
| | - Frank C. Nichols
- Division of Periodontology, UConn Health, Farmington, CT, United States
| | - Bing Hao
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
- Bing Hao,
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
- *Correspondence: Peter Setlow,
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19
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Fatton M, Filippidou S, Junier T, Cailleau G, Berge M, Poppleton D, Blum TB, Kaminek M, Odriozola A, Blom J, Johnson SL, Abrahams JP, Chain PS, Gribaldo S, Tocheva EI, Zuber B, Viollier PH, Junier P. Cryptosporulation in Kurthia spp. forces a rethinking of asporogenesis in Firmicutes. Environ Microbiol 2022; 24:6320-6335. [PMID: 36530021 PMCID: PMC10086788 DOI: 10.1111/1462-2920.16145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 07/20/2022] [Indexed: 01/12/2023]
Abstract
Endosporulation is a complex morphophysiological process resulting in a more resistant cellular structure that is produced within the mother cell and is called endospore. Endosporulation evolved in the common ancestor of Firmicutes, but it is lost in descendant lineages classified as asporogenic. While Kurthia spp. is considered to comprise only asporogenic species, we show here that strain 11kri321, which was isolated from an oligotrophic geothermal reservoir, produces phase-bright spore-like structures. Phylogenomics of strain 11kri321 and other Kurthia strains reveals little similarity to genetic determinants of sporulation known from endosporulating Bacilli. However, morphological hallmarks of endosporulation were observed in two of the four Kurthia strains tested, resulting in spore-like structures (cryptospores). In contrast to classic endospores, these cryptospores did not protect against heat or UV damage and successive sub-culturing led to the loss of the cryptosporulating phenotype. Our findings imply that a cryptosporulation phenotype may have been prevalent and subsequently lost by laboratory culturing in other Firmicutes currently considered as asporogenic. Cryptosporulation might thus represent an ancestral but unstable and adaptive developmental state in Firmicutes that is under selection under harsh environmental conditions.
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Affiliation(s)
- Mathilda Fatton
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Sevasti Filippidou
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.,AstrobiologyOU, The Open University, Milton Keynes, UK
| | - Thomas Junier
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.,Vital-IT group, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Guillaume Cailleau
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Matthieu Berge
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Daniel Poppleton
- Unité de Biologie Moléculaire du Gène chez les Extrémophiles, Département de Microbiologie, Institut Pasteur, France
| | - Thorsten B Blum
- Biology and Chemistry, Laboratory of Biomolecular Research, Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - Marek Kaminek
- Institute for Anatomy, University of Bern, Bern, Switzerland
| | | | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Shannon L Johnson
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Jan Pieter Abrahams
- Biology and Chemistry, Laboratory of Biomolecular Research, Paul Scherrer Institute (PSI), Villigen, Switzerland.,Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland.,Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Patrick S Chain
- Institute for Anatomy, University of Bern, Bern, Switzerland
| | - Simonetta Gribaldo
- Unité de Biologie Moléculaire du Gène chez les Extrémophiles, Département de Microbiologie, Institut Pasteur, France
| | - Elitza I Tocheva
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Benoît Zuber
- Institute for Anatomy, University of Bern, Bern, Switzerland
| | - Patrick H Viollier
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Pilar Junier
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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20
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Pacheco M, Dikec J, Winckler P, Coelho C, Perrier-Cornet JM. Spectroscopic and microscopic characterization of dipicolinic acid and its salt photoproducts - A UVc effect study on DPA in solution and in bacterial spores. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 280:121502. [PMID: 35752036 DOI: 10.1016/j.saa.2022.121502] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/10/2022] [Accepted: 06/12/2022] [Indexed: 06/15/2023]
Abstract
Bacterial spores can cause significant problems such as food poisoning (like neurotoxin or emetic toxin) or serious illnesses (like anthrax or botulism). This dormant form of bacteria, made of several layers of barriers which provide extreme resistance to many abiotic stresses (radiation, temperature, pressure, etc.), are difficult to investigate in situ. To better understand the biological and chemical mechanisms involved and specific to spores resistance, the acquisition of environmental parameters is necessary. For that purpose, our research has been focused on the detection and analysis of a unique spore component, dipicolinic acid (DPA), used as the main in situ metabolite for sporulating bacteria detection. In its native form, DPA is only weakly fluorescent but after Ultraviolet irradiation at the wavelength of 254 nm (UVc), DPA photoproducts (DPAp) exhibit a remarkable fluorescence signal. These photoproducts are rarely identified and part of this study gives new insights offered by mass spectrometry (MS) in the determination of DPA photoproducts. Thanks to DPA assay techniques and fluorescence spectrometry, we highlighted the instability of photoproducts and introduced new assumptions on the effects of UVc on DPA. Studies in spectroscopy and microscopy allowed us to better understand these native probes in bacterial spores and will allow the implementation of a new method for studying the physico-chemical parameters of spore resistance.
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Affiliation(s)
- Maxime Pacheco
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France
| | - Jonathan Dikec
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France
| | - Pascale Winckler
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France; Dimacell Imaging Facility, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1 Esplanade Erasme, 21000 Dijon, France
| | - Christian Coelho
- Université Clermont Auvergne, INRAE, VetAgro Sup campus agronomique de Lempdes, UMR F, 15000 Aurillac, France
| | - Jean-Marie Perrier-Cornet
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France; Dimacell Imaging Facility, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1 Esplanade Erasme, 21000 Dijon, France.
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21
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Horne WH, Volpe RP, Korza G, DePratti S, Conze IH, Shuryak I, Grebenc T, Matrosova VY, Gaidamakova EK, Tkavc R, Sharma A, Gostinčar C, Gunde-Cimerman N, Hoffman BM, Setlow P, Daly MJ. Effects of Desiccation and Freezing on Microbial Ionizing Radiation Survivability: Considerations for Mars Sample Return. ASTROBIOLOGY 2022; 22:1337-1350. [PMID: 36282180 PMCID: PMC9618380 DOI: 10.1089/ast.2022.0065] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
Increasingly, national space agencies are expanding their goals to include Mars exploration with sample return. To better protect Earth and its biosphere from potential extraterrestrial sources of contamination, as set forth in the Outer Space Treaty of 1967, international efforts to develop planetary protection measures strive to understand the danger of cross-contamination processes in Mars sample return missions. We aim to better understand the impact of the martian surface on microbial dormancy and survivability. Radiation resistance of microbes is a key parameter in considering survivability of microbes over geologic times on the frigid, arid surface of Mars that is bombarded by solar and galactic cosmic radiation. We tested the influence of desiccation and freezing on the ionizing radiation survival of six model microorganisms: vegetative cells of two bacteria (Deinococcus radiodurans, Escherichia coli) and a strain of budding yeast (Saccharomyces cerevisiae); and vegetative cells and endospores of three Bacillus bacteria (B. subtilis, B. megaterium, B. thuringiensis). Desiccation and freezing greatly increased radiation survival of vegetative polyploid microorganisms when applied separately, and when combined, desiccation and freezing increased radiation survival even more so. Thus, the radiation survival threshold of polyploid D. radiodurans cells can be extended from the already high value of 25 kGy in liquid culture to an astonishing 140 kGy when the cells are both desiccated and frozen. However, such synergistic radioprotective effects of desiccation and freezing were not observed in monogenomic or digenomic Bacillus cells and endospores, which are generally sterilized by 12 kGy. This difference is associated with a critical requirement for survivability under radiation, that is, repair of genome damage caused by radiation. Deinococcus radiodurans and S. cerevisiae accumulate similarly high levels of the Mn antioxidants that are required for extreme radiation resistance, as do endospores, though they greatly exceed spores in radioresistance because they contain multiple identical genome copies, which in D. radiodurans are joined by persistent Holliday junctions. We estimate ionizing radiation survival limits of polyploid DNA-based life-forms to be hundreds of millions of years of background radiation while buried in the martian subsurface. Our findings imply that forward contamination of Mars will essentially be permanent, and backward contamination is a possibility if life ever existed on Mars.
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Affiliation(s)
- William H. Horne
- School of Medicine, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Department of Chemistry and Life Science, United States Military Academy, West Point, New York, USA
| | - Robert P. Volpe
- School of Medicine, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - George Korza
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Sarah DePratti
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Isabel H. Conze
- School of Medicine, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Igor Shuryak
- Center for Radiological Research, Columbia University Irving Medical Center (CUIMC), New York, New York, USA
| | - Tine Grebenc
- Slovenian Forestry Institute, Ljubljana, Slovenia
| | - Vera Y. Matrosova
- School of Medicine, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Elena K. Gaidamakova
- School of Medicine, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Rok Tkavc
- School of Medicine, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Ajay Sharma
- Department of Chemistry, Northwestern University, Evanston, Illinois, USA
| | - Cene Gostinčar
- Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | | | - Brian M. Hoffman
- Department of Chemistry, Northwestern University, Evanston, Illinois, USA
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Michael J. Daly
- School of Medicine, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Member, Committee on Planetary Protection (CoPP), National Academies of Sciences, Washington, DC, USA
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22
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Dikec J, Pacheco M, Lavaud M, Winckler P, Perrier-Cornet JM. Uptake of UVc induced photoproducts of dipicolinic acid by Bacillus subtilis spores - Effects on the germination and UVc resistance of the spores. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 236:112569. [PMID: 36152351 DOI: 10.1016/j.jphotobiol.2022.112569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/05/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
Dipicolinic acid (DPA) is a specific molecule of bacterial spores which is essential to their resistance to various stresses such as ultraviolet (UV) exposure and to their germination. DPA has a particular photochemistry that remains imperfectly understood. In particular, due to its ability to absorb UVc radiation, it is likely to form in vitro a wide variety of photoproducts (DPAp) of which only about ten have been recently identified. The photochemical reactions resulting in DPAp, especially those inside the spores, are still poorly understood. Only one of these DPAp, which probably acts as a photosensitizer of DNA upon exposure to UVc, has been identified as having an impact on spores. However, as UVc is required to form DPAp, it is difficult to decouple the overall effect of UVc exposure from the possible effects of DPAp alone. In this study, DPAp were artificially introduced into the spores of the FB122 mutant strain of Bacillus subtilis, one that does not produce DPA. These experiments revealed that some DPAp may play a positive role for the spore. These benefits are visible in an improvement in spore germination rate and kinetics, as well as in an increase in their resistance to UVc exposure.
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Affiliation(s)
- J Dikec
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France
| | - M Pacheco
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France
| | - M Lavaud
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France; Dimacell Imaging Facility, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1 Esplanade Erasme, 21000 Dijon, France
| | - P Winckler
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France; Dimacell Imaging Facility, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1 Esplanade Erasme, 21000 Dijon, France
| | - J M Perrier-Cornet
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France; Dimacell Imaging Facility, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1 Esplanade Erasme, 21000 Dijon, France.
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23
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Dikec J, Bechoua N, Winckler P, Perrier-Cornet JM. Effects of pulsed near infrared light (NIR) on Bacillus subtilis spores. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 234:112530. [PMID: 35930949 DOI: 10.1016/j.jphotobiol.2022.112530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/13/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
In this study, we develop a characterization of bacterial spore resistance to NIR pulsed light under modalities traditionally used in multiphoton microscopy. Energy dose and laser power are both key parameters in spore and bacterial cell inactivation. Surprisingly, spores and vegetative cells seem to show a similar sensitivity to pulsed NIR, spores being only 2-fold more resistant than their vegetative counterparts. This work enables us to eliminate certain hypotheses concerning the main driver of spore inactivation processes. Our findings suggest that damage leading to inactivation is mainly caused by photochemical reactions characterized by multiple possible pathways, including DNA damage or oxidation processes.
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Affiliation(s)
- J Dikec
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France
| | - N Bechoua
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France
| | - P Winckler
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France; Dimacell Imaging Facility, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1 Esplanade Erasme, 21000 Dijon, France
| | - J M Perrier-Cornet
- UMR Procédés Alimentaires et Microbiologiques, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1, Esplanade Erasme, 21000 Dijon, France; Dimacell Imaging Facility, L'Institut Agro Dijon, Université de Bourgogne Franche-Comté, 1 Esplanade Erasme, 21000 Dijon, France.
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24
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Yu L, Feng L, Xiong L, Li S, Wang S, Wei Z, Xiao Y. Portable visual assay of Bacillus anthracis biomarker based on ligand-functionalized dual-emission lanthanide metal-organic frameworks and smartphone-integrated mini-device. JOURNAL OF HAZARDOUS MATERIALS 2022; 434:128914. [PMID: 35452990 DOI: 10.1016/j.jhazmat.2022.128914] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/01/2022] [Accepted: 04/11/2022] [Indexed: 06/14/2023]
Abstract
A single-functionalized ligand single-Ln3+ based dual-emission Ln-MOF fluorescent sensor was established for portable and visual dipicolinic acid (DPA, Bacillus anthracis biomarker) detection. First, a theory calculation-based prediction model was developed for designing single-functionalized ligand single-Ln3+ dual-emission Ln-MOFs. The model consisted of three calculation modules: intramolecular hydrogen bonds, excited state energy levels, and coordination stability with Ln3+ of ligands. Tb3+ and Eu3+ were selected as metal luminescence centers, PTA-X (PTA: p-phthalic acid, X = NH2, CH3, H, OH) with different functional groups as one-step functionalization ligands, and the luminescent feature of four Tb-MOFs and four Eu-MOFs was predicted with the model. Coupled with prediction results and experimental verification results, Tb-PTA-OH was rapidly determined to be the sole dual-emission Ln-MOF. Then, Tb-PTA-OH was applied to DPA detection by ratiometric fluorescence, and an ultra-low limit of detection (13.4 nM) was obtained, which is much lower than the lowest anthrax infectious dose (60 μM). A portable visual assay method based on paper-microchip and smartphone integrated mini-device was further established (limit of qualification 0.48 μM). A new sensing mechanism and a "triple gates" selectivity mechanism to DPA were proposed. This work reveals guidelines for material design and mini-device customization in detecting hazardous substances.
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Affiliation(s)
- Long Yu
- Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), Wuhan 430071, China
| | - Lixiang Feng
- Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), Wuhan 430071, China
| | - Li Xiong
- Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), Wuhan 430071, China
| | - Shuo Li
- Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), Wuhan 430071, China
| | - Shuo Wang
- Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), Wuhan 430071, China
| | - Zhongyu Wei
- Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), Wuhan 430071, China
| | - Yuxiu Xiao
- Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), Wuhan 430071, China.
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25
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Subirats J, Sharpe H, Topp E. Fate of Clostridia and other spore-forming Firmicute bacteria during feedstock anaerobic digestion and aerobic composting. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 309:114643. [PMID: 35151135 DOI: 10.1016/j.jenvman.2022.114643] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/26/2022] [Accepted: 01/30/2022] [Indexed: 06/14/2023]
Abstract
Pathogenic spore-forming Firmicutes are commonly present in animal and human wastes that are used as fertilizers in crop production. Pre-treatments of organic waste prior to land application offer the potential to abate enteric microorganisms, and therefore reduce the risk of contamination of crops or adjacent water resources with pathogens carried in these materials. The inactivation and reduction of gram-positive spore formers such as Clostridium spp., Clostridioides spp. and Bacillus spp. from animal and human waste can be challenging given the recalcitrance of the spores these bacteria produce. Given the significance of these organisms to human and animal health, information concerning spore-forming bacteria inactivation during anaerobic digestion (AD) and aerobic composting (AC) is required as the basis for recommending safe organic waste management practices. In this review, an assessment of the inactivation of spore-forming Firmicutes during AD and AC was conducted to provide guidance for practical management of organic matrices of animal or human origin. Temperature and pH may be the main factors contributing to the inactivation of spore-forming Firmicutes during batch lab-scale AD (log reduction <0.5-5 log). In continuous digesters, wet AD systems do not effectively inactivate spore-forming Firmicutes even under thermopholic conditions (log reduction -1.09 - 0.98), but dry AD systems could be a feasible management practice to inactivate spore-forming Firmicutes from organic materials with high solid content (log reduction 1.77-3.1). In contrast, composting is an effective treatment to abate spore-forming Firmicutes (log reduction 1.7-6.5) when thermophilic conditions last at least six consecutive days. Temperature, moisture content and composting scale are the key operating conditions influencing the inactivation of spore-forming Firmicutes during composting. Where possible, undertaking AD with subsequent composting to ensure the biosafety of digestate before its downstream processing and recycling is recommended to abate recalcitrant bacteria in digestate.
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Affiliation(s)
- Jessica Subirats
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, Ontario, Canada; Department of Biology, University of Western Ontario, London, Ontario, Canada.
| | - Hannah Sharpe
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, Ontario, Canada; Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Edward Topp
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, Ontario, Canada; Department of Biology, University of Western Ontario, London, Ontario, Canada.
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26
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Zhu Y, Liu W, Liu S, Li M, Zhao L, Xu L, Wang N, Zhao G, Yu Q. Preparation of AgNPs self-assembled solid-phase substrate via seed-mediated growth for rapid identification of different bacterial spores based on SERS. Food Res Int 2022; 160:111426. [DOI: 10.1016/j.foodres.2022.111426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 11/04/2022]
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27
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Amon JD, Artzi L, Rudner DZ. Genetic Evidence for Signal Transduction within the Bacillus subtilis GerA Germinant Receptor. J Bacteriol 2022; 204:e0047021. [PMID: 34780301 PMCID: PMC8846391 DOI: 10.1128/jb.00470-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/06/2021] [Indexed: 11/20/2022] Open
Abstract
Bacterial spores can rapidly exit dormancy through the process of germination. This process begins with the activation of nutrient receptors embedded in the spore membrane. The prototypical germinant receptor in Bacillus subtilis responds to l-alanine and is thought to be a complex of proteins encoded by the genes in the gerA operon: gerAA, gerAB, and gerAC. The GerAB subunit has recently been shown to function as the nutrient sensor, but beyond contributing to complex stability, no additional functions have been attributed to the other two subunits. Here, we investigate the role of GerAA. We resurrect a previously characterized allele of gerA (termed gerA*) that carries a mutation in gerAA and show that it constitutively activates germination even in the presence of a wild-type copy of gerA. Using an enrichment strategy to screen for suppressors of gerA*, we identified mutations in all three gerA genes that restore a functional receptor. Characterization of two distinct gerAB suppressors revealed that one (gerAB[E105K]) reduces the GerA complex's ability to respond to l-alanine, while another (gerAB[F259S]) disrupts the germinant signal downstream of l-alanine recognition. These data argue against models in which GerAA is directly or indirectly involved in germinant sensing. Rather, our data suggest that GerAA is responsible for transducing the nutrient signal sensed by GerAB. While the steps downstream of gerAA have yet to be uncovered, these results validate the use of a dominant-negative genetic approach in elucidating the gerA signal transduction pathway. IMPORTANCE Endospore formers are a broad group of bacteria that can enter dormancy upon starvation and exit dormancy upon sensing the return of nutrients. How dormant spores sense and respond to these nutrients is poorly understood. Here, we identify a key step in the signal transduction pathway that is activated after spores detect the amino acid l-alanine. We present a model that provides a more complete picture of this process that is critical for allowing dormant spores to germinate and resume growth.
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Affiliation(s)
- Jeremy D. Amon
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Lior Artzi
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - David Z. Rudner
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
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28
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Shin H, Kwon CW, Lee MW, Yu H, Chang PS. Antibacterial characterization of erythorbyl laurate against Geobacillus stearothermophilus spores. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2021.112824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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29
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Moderate high-pressure superdormancy in Bacillus spores: properties of superdormant spores and proteins potentially influencing moderate high-pressure germination. Appl Environ Microbiol 2021; 88:e0240621. [PMID: 34910565 PMCID: PMC8863042 DOI: 10.1128/aem.02406-21] [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] [Indexed: 11/24/2022] Open
Abstract
Resistant bacterial spores are a major concern in industrial decontamination processes. An approach known as pressure-mediated germination-inactivation strategy aims to artificially germinate spores by isostatic pressure to mitigate their resistance to inactivation processes. The successful implementation of such a germination-inactivation strategy relies on the germination of all spores. However, germination is heterogeneous, with some “superdormant” spores germinating extremely slowly or not at all. The present study investigated potential underlying reasons for moderate high-pressure (150 MPa; 37°C) superdormancy of Bacillus subtilis spores. The water and dipicolinic acid content of superdormant spores was compared with that of the initial dormant spore population. The results suggest that water and dipicolinic acid content are not major drivers of moderate high-pressure superdormancy. A proteomic analysis was used to identify proteins that were quantified at significantly different levels in superdormant spores. Subsequent validation of the germination capacity of deletion mutants revealed that the presence of protein YhcN is required for efficient moderate high-pressure germination and that proteins MinC, cse60, and SspK may also play a role, albeit a minor one. IMPORTANCE Spore-forming bacteria are ubiquitous in nature and, as a consequence, inevitably enter the food chain or other processing environments. Their presence can lead to significant spoilage or safety-related issues. Intensive treatment is usually required to inactivate them; however, this treatment harms important product quality attributes. A pressure-mediated germination-inactivation approach can balance the need for effective spore inactivation and retention of sensitive ingredients. However, superdormant spores are the bottleneck preventing the successful and safe implementation of such a strategy. An in-depth understanding of moderate high-pressure germination and the underlying causes of superdormancy is necessary to advance the development of mild high pressure-based spore control technologies. The approach used in this work allowed the identification of proteins that have not yet been associated with reduced germination at moderate high pressure. This research paves the way for further studies on the germination and superdormancy mechanisms in spores, assisting the development of mild spore inactivation strategies.
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Ran X, Zhu Z, Long H, Tian Q, You L, Wu X, Liu Q, Huang S, Li S, Niu X, Wang J. Manganese Stress Adaptation Mechanisms of Bacillus safensis Strain ST7 From Mine Soil. Front Microbiol 2021; 12:758889. [PMID: 34899642 PMCID: PMC8656422 DOI: 10.3389/fmicb.2021.758889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 10/21/2021] [Indexed: 11/23/2022] Open
Abstract
The mechanism of bacterial adaption to manganese-polluted environments was explored using 50 manganese-tolerant strains of bacteria isolated from soil of the largest manganese mine in China. Efficiency of manganese removal by the isolated strains was investigated using atomic absorption spectrophotometry. Bacillus safensis strain ST7 was the most effective manganese-oxidizing bacteria among the tested isolates, achieving up to 82% removal at a Mn(II) concentration of 2,200 mg/L. Bacteria-mediated manganese oxide precipitates and high motility were observed, and the growth of strain ST7 was inhibited while its biofilm formation was promoted by the presence of Mn(II). In addition, strain ST7 could grow in the presence of high concentrations of Al(III), Cr(VI), and Fe(III). Genome-wide analysis of the gene expression profile of strain ST7 using the RNA-seq method revealed that 2,580 genes were differently expressed under Mn(II) exposure, and there were more downregulated genes (n = 2,021) than upregulated genes (n = 559) induced by Mn stress. KAAS analysis indicated that these differently expressed genes were mainly enriched in material metabolisms, cellular processes, organism systems, and genetic and environmental information processing pathways. A total of twenty-six genes from the transcriptome of strain ST7 were involved in lignocellulosic degradation. Furthermore, after 15 genes were knocked out by homologous recombination technology, it was observed that the transporters, multicopper oxidase, and proteins involved in sporulation and flagellogenesis contributed to the removal of Mn(II) in strain ST7. In summary, B. safensis ST7 adapted to Mn exposure by changing its metabolism, upregulating cation transporters, inhibiting sporulation and flagellogenesis, and activating an alternative stress-related sigB pathway. This bacterial strain could potentially be used to restore soil polluted by multiple heavy metals and is a candidate to support the consolidated bioprocessing community.
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Affiliation(s)
- Xueqin Ran
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Zhongmei Zhu
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Hong Long
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Qun Tian
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Longjiang You
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Xingdiao Wu
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Qin Liu
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Shihui Huang
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Sheng Li
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Xi Niu
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Jiafu Wang
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Animal Science/Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
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Sun R, Vermeulen A, Wieme AD, Vandamme P, Devlieghere F. Identification and characterization of acid-tolerant spore-forming spoilage bacteria from acidified and low-acid pasteurized sauces. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.112378] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Zhang Z, Li J, Zhang Z, Liu Y, Wei Y. Tomato Endophytic Bacteria Composition and Mechanism of Suppressiveness of Wilt Disease ( Fusarium oxysporum). Front Microbiol 2021; 12:731764. [PMID: 34721330 PMCID: PMC8555416 DOI: 10.3389/fmicb.2021.731764] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/16/2021] [Indexed: 11/13/2022] Open
Abstract
Tomato wilt disease, caused by the Fusarium oxysporum is an ever-increasing threat for agricultural production, and unreasonable fertilization and pesticide abuse caused environmental challenge. Increasing evidence suggested that microbiomes or those associated with crops, played key roles on plant health. Plant disease dynamics were affected by multiple biotic and abiotic factors including phytopathogen population density, the genetic type of the pathogen and the host, in particular, the composition and assembly of the host-associated microbiome. However, it was unclear how pathogen invasion interaction and correlate with endophytic bacterial communities in natural field conditions. To study this, we sampled temporally the tomato plants that were exposed to F. oxysporum invasions over one crop season. High-throughput sequencing were performed to explore the correlation between agricultural practice, pathogen invasion, and endophytic microbiota communities. Results showed that pathogen invasion had clear effect on the endophytic and a strong link between increased pathogen densities and reduced abundance of Bacillus sp., which are crucial taxonomy for suppressiveness to F. oxysporum in vitro and in greenhouse condition. In summary, monitoring the dynamics of endophytic bacteria communities and densities of pathogen could thus open new avenue for more accurate disease diagnostics and high-efficiency screening antagonisms methods in the future, and our results will broaden the agricultural view of beneficial microbiota as biological control agents against plant pathogen.
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Affiliation(s)
- Zeyu Zhang
- College of Resources and Environmental Science, China Agricultural University, Beijing, China
| | - Ji Li
- College of Resources and Environmental Science, China Agricultural University, Beijing, China
| | - Zengqiang Zhang
- College of Natural Resources and Environment, Northwest A&F University, Xianyang, China
| | - Youzhou Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences (JAAS), Nanjing, China
| | - Yuquan Wei
- College of Resources and Environmental Science, China Agricultural University, Beijing, China
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Kanaan J, Murray J, Higgins R, Nana M, DeMarco AM, Korza G, Setlow P. Resistance properties and the role of the inner membrane and coat of Bacillus subtilis spores with extreme wet heat resistance. J Appl Microbiol 2021; 132:2157-2166. [PMID: 34724311 DOI: 10.1111/jam.15345] [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: 08/24/2021] [Revised: 10/01/2021] [Accepted: 10/28/2021] [Indexed: 11/27/2022]
Abstract
AIMS A protein termed 2Duf greatly increases wet heat resistance of Bacillus subtilis spores. The current work examines the effects of 2Duf on spore resistance to other sporicides, including chemicals that act on or must cross spores' inner membrane (IM), where 2Duf is likely present. The overall aim was to gain a deeper understanding of how 2Duf affects spore resistance, and of spore resistance itself. METHODS AND RESULTS 2Duf's presence increased spore resistance to chemicals that damage or must cross the IM to kill spores. Spore coat removal decreased 2Duf-spore resistance to chemicals and wet heat, and 2Duf-spores made at higher temperatures were more resistant to wet heat and chemicals. 2Duf-less spores lacking coats and Ca-dipicolinic acid were also extremely sensitive to wet heat and chemicals that transit the IM to kill spores. CONCLUSIONS The new work plus previous results lead to a number of important conclusions as follows. (1) 2Duf may influence spore resistance by decreasing the permeability of and lipid mobility in spores' IM. (2) Since wet heat-killed spores that germinate do not accumulate ATP, wet heat may inactivate some spore IM protein essential in ATP production which is stabilized in a more rigid IM. (3) Both Ca-dipicolinic acid and the spore coat play an important role in the permeability of the spore IM, and thus in many spore resistance properties. SIGNIFICANCE AND IMPACT OF THE STUDY The work in this manuscript gives a new insight into mechanisms of spore resistance to chemicals and wet heat, to the understanding of spore wet heat killing, and the role of Ca-dipicolinic acid and the coat in spore resistance.
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Affiliation(s)
- Julia Kanaan
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Jillian Murray
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Ryan Higgins
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Mishil Nana
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Angela M DeMarco
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - George Korza
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
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Sinnelä MT, Pawluk AM, Jin YH, Kim D, Mah JH. Effect of Calcium and Manganese Supplementation on Heat Resistance of Spores of Bacillus Species Associated With Food Poisoning, Spoilage, and Fermentation. Front Microbiol 2021; 12:744953. [PMID: 34707595 PMCID: PMC8542979 DOI: 10.3389/fmicb.2021.744953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/22/2021] [Indexed: 11/30/2022] Open
Abstract
Bacterial spores often survive thermal processing used in the food industry, while heat treatment leads not only to a decrease in the nutritional and organoleptic properties of foods, but also to a delay in fermentation of fermented foods. Selective reduction of undesirable spores without such impediments is an ongoing challenge for food scientists. Thus, increased knowledge of the spore-forming bacteria is required to control them. In this study, the heat resistance results (D100°C) of the spores of four Bacillus species were determined and compared to previous literature, and found that B. cereus has significantly lower heat resistance than the other Bacillus species, B. coagulans, B. subtilis, and B. licheniformis. Using the spores of these strains, this study also evaluated the effects of single and combined supplementation of calcium (0.00–2.00 mM) and manganese (0.00–0.50 mM) on heat resistance (D100°C). The results revealed that the spores of B. licheniformis and B. cereus displayed the smallest heat resistance when sporulated on media rich in calcium. Conversely, B. coagulans spores and B. subtilis spores exhibited the greatest heat resistance when sporulated under calcium-rich conditions. The opposite results (stronger heat resistance for B. licheniformis spores and B. cereus spores, and smaller heat resistance for B. coagulans spores and B. subtilis spores) were obtained when the spores were formed on media poor in the minerals (particularly calcium). Based on the results, the Bacillus species were divided into two groups: B. licheniformis and B. cereus; and B. coagulans and B. subtilis. The study provides valuable insight to selectively reduce spores of undesirable Bacillus species in the food industry.
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Affiliation(s)
| | | | - Young Hun Jin
- Department of Food and Biotechnology, Korea University, Sejong, South Korea
| | - Dabin Kim
- Department of Food and Biotechnology, Korea University, Sejong, South Korea
| | - Jae-Hyung Mah
- Department of Food and Biotechnology, Korea University, Sejong, South Korea
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Craft DL, Korza G, Zhang Y, Frindert J, Jäschke A, Caimano MJ, Setlow P. Analysis of 5'-NAD capping of mRNAs in dormant spores of Bacillus subtilis. FEMS Microbiol Lett 2021; 367:5895323. [PMID: 32821945 DOI: 10.1093/femsle/fnaa143] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 08/18/2020] [Indexed: 12/24/2022] Open
Abstract
Spores of Gram-positive bacteria contain 10s-1000s of different mRNAs. However, Bacillus subtilis spores contain only ∼ 50 mRNAs at > 1 molecule/spore, almost all transcribed only in the developing spore and encoding spore proteins. However, some spore mRNAs could be stabilized to ensure they are intact in dormant spores, perhaps to direct synthesis of proteins essential for spores' conversion to a growing cell in germinated spore outgrowth. Recent work shows that some growing B. subtilis cell mRNAs contain a 5'-NAD cap. Since this cap may stabilize mRNA in vivo, its presence on spore mRNAs would suggest that maintaining some intact spore mRNAs is important, perhaps because they have a translational role in outgrowth. However, significant levels of only a few abundant spore mRNAs had a 5'-NAD cap, and these were not the most stable spore mRNAs and had likely been fragmented. Even higher levels of 5'-NAD-capping were found on a few low abundance spore mRNAs, but these mRNAs were present in only small percentages of spores, and had again been fragmented. The new data are thus consistent with spore mRNAs serving only as a reservoir of ribonucleotides in outgrowth.
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Affiliation(s)
- D Levi Craft
- Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06030-3305, USA
| | - George Korza
- Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06030-3305, USA
| | - Yaqing Zhang
- Institute of Pharmacy and Molecular Biotechnology, Im Neuenheimer Feld, Heidelberg University, 69120, Heidelberg, Germany
| | - Jens Frindert
- Institute of Pharmacy and Molecular Biotechnology, Im Neuenheimer Feld, Heidelberg University, 69120, Heidelberg, Germany
| | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology, Im Neuenheimer Feld, Heidelberg University, 69120, Heidelberg, Germany
| | - Melissa J Caimano
- Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06030-3305, USA.,Department of Medicine, UConn Health, Farmington, CT 06030-3305, USA
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06030-3305, USA
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Abstract
Biofilm dispersion is the final stage of biofilm development, during which biofilm cells actively escape from biofilms in response to deteriorating conditions within the biofilm. Biofilm dispersion allows cells to spread to new locations and form new biofilms in better locations. However, dispersal mechanisms have been elucidated only in a limited number of bacteria. Here, we investigated biofilm dispersion in Bacillus subtilis. Biofilm dispersion was clearly observed when B. subtilis was grown under static conditions in modified LB medium containing glycerol and manganese. Biofilm dispersion was synergistically caused by two mechanisms: decreased expression of the epsA operon encoding exopolysaccharide synthetases and the induction of sporulation. Indeed, constitutive expression of the epsA operon in the sporulation-defective ΔsigK mutant prevented biofilm dispersion. The addition of calcium to the medium prevented biofilm dispersion without significantly affecting the expression of the epsA operon and sporulation genes. In synthetic medium, eliminating calcium did not prevent the expression of biofilm matrix genes and, thereby, biofilm formation, but it attenuated biofilm architecture. These results indicate that calcium structurally stabilizes biofilms and causes resistance to biofilm dispersion mechanisms. Sporulation-dependent biofilm dispersion required the spoVF operon, encoding dipicolinic acid (DPA) synthase. During sporulation, an enormous amount of DPA is synthesized and stored in spores as a chelate with calcium. We speculate that, during sporulation, calcium bound to biofilm matrix components may be transported to spores as a calcium-DPA complex, which weakens biofilm structure and leads to biofilm dispersion. IMPORTANCE Bacteria growing as biofilms are notoriously difficult to eradicate and sometimes pose serious threats to public health. Bacteria escape from biofilms by degrading them when biofilm conditions deteriorate. This process, called biofilm dispersion, has been studied as a promising strategy for safely controlling biofilms. However, the regulation and mechanism of biofilm dispersion has been elucidated only in a limited number of bacteria. Here, we identified two biofilm dispersion mechanisms in the Gram-positive, spore-forming bacterium Bacillus subtilis. The addition of calcium to the medium stabilized biofilms and caused resistance to dispersal mechanisms. Our findings provide new insights into biofilm dispersion and biofilm control.
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Levels and Characteristics of mRNAs in Spores of Firmicute Species. J Bacteriol 2021; 203:e0001721. [PMID: 33972352 DOI: 10.1128/jb.00017-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spores of firmicute species contain 100s of mRNAs, whose major function in Bacillus subtilis is to provide ribonucleotides for new RNA synthesis when spores germinate. To determine if this is a general phenomenon, RNA was isolated from spores of multiple firmicute species and relative mRNA levels determined by transcriptome sequencing (RNA-seq). Determination of RNA levels in single spores allowed calculation of RNA nucleotides/spore, and assuming mRNA is 3% of spore RNA indicated that only ∼6% of spore mRNAs were present at >1/spore. Bacillus subtilis, Bacillus atrophaeus, and Clostridioides difficile spores had 49, 42, and 51 mRNAs at >1/spore, and numbers of mRNAs at ≥1/spore were ∼10 to 50% higher in Geobacillus stearothermophilus and Bacillus thuringiensis Al Hakam spores and ∼4-fold higher in Bacillus megaterium spores. In all species, some to many abundant spore mRNAs (i) were transcribed by RNA polymerase with forespore-specific σ factors, (ii) encoded proteins that were homologs of those encoded by abundant B. subtilis spore mRNAs and are proteins in dormant spores, and (iii) were likely transcribed in the mother cell compartment of the sporulating cell. Analysis of the coverage of RNA-seq reads on mRNAs from all species suggested that abundant spore mRNAs were fragmented, as was confirmed by reverse transcriptase quantitative PCR (RT-qPCR) analysis of abundant B. subtilis and C. difficile spore mRNAs. These data add to evidence indicating that the function of at least the great majority of mRNAs in all firmicute spores is to be degraded to generate ribonucleotides for new RNA synthesis when spores germinate. IMPORTANCE Only ∼6% of mRNAs in spores of six firmicute species are at ≥1 molecule/spore, many abundant spore mRNAs encode proteins similar to B. subtilis spore proteins, and some abundant B. subtilis and C. difficile spore mRNAs were fragmented. Most of the abundant B. subtilis and other Bacillales spore mRNAs are transcribed under the control of the forespore-specific RNA polymerase σ factors, F or G, and these results may stimulate transcription analyses in developing spores of species other than B. subtilis. These findings, plus the absence of key nucleotide biosynthetic enzymes in spores, suggest that firmicute spores' abundant mRNAs are not translated when spores germinate but instead are degraded to generate ribonucleotides for new RNA synthesis by the germinated spore.
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Delbrück AI, Zhang Y, Heydenreich R, Mathys A. Bacillus spore germination at moderate high pressure: A review on underlying mechanisms, influencing factors, and its comparison with nutrient germination. Compr Rev Food Sci Food Saf 2021; 20:4159-4181. [PMID: 34147040 DOI: 10.1111/1541-4337.12789] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 02/05/2023]
Abstract
Spore-forming bacteria are resistant to stress conditions owing to their ability to form highly resistant dormant spores. These spores can survive adverse environmental conditions in nature, as well as decontamination processes in the food and related industries. Bacterial spores may return to their vegetative state through a process called germination. As spore germination is critical for the loss of resistance, outgrowth, and development of pathogenicity and spoilage potential, the germination pathway has piqued the interest of the scientific community. The inhibition and induction of germination have critical applications in the food industry. Targeted germination can aid in decreasing the resistance of spores and allow the application of milder inactivation procedures. This germination-inactivation strategy allows better maintenance of important food quality attributes. Different stimuli are reported to trigger germination. Among those, isostatic high pressure (HP) has gained increasing attention due to its potential applications in industrial processes. However, pressure-mediated spore germination is extremely heterogeneous as some spores germinate rapidly, while others exhibit slow germination or do not undergo germination at all. The successful and safe implementation of the germination-inactivation strategy, however, depends on the germination of all spores. Therefore, there is a need to elucidate the mechanisms of HP-mediated germination. This work aimed to critically review the current state of knowledge on Bacillus spore germination at a moderate HP of 50-300 MPa. In this review, the germination mechanism, heterogeneity, and influencing factors have been outlined along with knowledge gaps.
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Affiliation(s)
- Alessia I Delbrück
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, Department of Health Science and Technology, ETH Zürich, Zurich, Switzerland
| | - Yifan Zhang
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, Department of Health Science and Technology, ETH Zürich, Zurich, Switzerland
| | - Rosa Heydenreich
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, Department of Health Science and Technology, ETH Zürich, Zurich, Switzerland
| | - Alexander Mathys
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, Department of Health Science and Technology, ETH Zürich, Zurich, Switzerland
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Abstract
Clostridioides difficile is a leading cause of health care-associated infections worldwide. These infections are transmitted by C. difficile′s metabolically dormant, aerotolerant spore form. Functional spore formation depends on the assembly of two protective layers, a thick layer of modified peptidoglycan known as the cortex layer and a multilayered proteinaceous meshwork known as the coat. We previously identified two spore morphogenetic proteins, SpoIVA and SipL, that are essential for recruiting coat proteins to the developing forespore and making functional spores. While SpoIVA and SipL directly interact, the identities of the proteins they recruit to the forespore remained unknown. Here, we used mass spectrometry-based affinity proteomics to identify proteins that interact with the SpoIVA-SipL complex. These analyses identified the Peptostreptococcaceae family-specific, sporulation-induced bitopic membrane protein CD3457 (renamed SpoVQ) as a protein that interacts with SipL and SpoIVA. Loss of SpoVQ decreased heat-resistant spore formation by ∼5-fold and reduced cortex thickness ∼2-fold; the thinner cortex layer of ΔspoVQ spores correlated with higher levels of spontaneous germination (i.e., in the absence of germinant). Notably, loss of SpoVQ in either spoIVA or sipL mutants prevented cortex synthesis altogether and greatly impaired the localization of a SipL-mCherry fusion protein around the forespore. Thus, SpoVQ is a novel regulator of C. difficile cortex synthesis that appears to link cortex and coat formation. The identification of SpoVQ as a spore morphogenetic protein further highlights how Peptostreptococcaceae family-specific mechanisms control spore formation in C. difficile. IMPORTANCE The Centers for Disease Control has designated Clostridioides difficile as an urgent threat because of its intrinsic antibiotic resistance. C. difficile persists in the presence of antibiotics in part because it makes metabolically dormant spores. While recent work has shown that preventing the formation of infectious spores can reduce C. difficile disease recurrence, more selective antisporulation therapies are needed. The identification of spore morphogenetic factors specific to C. difficile would facilitate the development of such therapies. In this study, we identified SpoVQ (CD3457) as a spore morphogenetic protein specific to the Peptostreptococcaceae family that regulates the formation of C. difficile’s protective spore cortex layer. SpoVQ acts in concert with the known spore coat morphogenetic factors, SpoIVA and SipL, to link formation of the protective coat and cortex layers. These data reveal a novel pathway that could be targeted to prevent the formation of infectious C. difficile spores.
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Luo Y, Korza G, DeMarco AM, Kuipers OP, Li YQ, Setlow P. Properties of spores of Bacillus subtilis with or without a transposon that decreases spore germination and increases spore wet heat resistance. J Appl Microbiol 2021; 131:2918-2928. [PMID: 34042237 DOI: 10.1111/jam.15163] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/14/2021] [Accepted: 05/03/2021] [Indexed: 01/01/2023]
Abstract
AIMS This work aimed to determine how genes on transposon Tn1546 slow Bacillus subtilis spore germination and increase wet heat resistance, and to clarify the transposon's 3 gene spoVA operon's role in spore properties, since the seven wild-type SpoVA proteins form a channel transporting Ca2+ -dipicolinic acid (DPA) in spore formation and germination. METHODS AND RESULTS Deletion of the wild-type spoVA operon from a strain with Tn1546 gave spores with slightly reduced wet heat resistance but some large decreases in germination rate. Spore water content and CaDPA analyses found no significant differences in contents of either component in spores with different Tn1546 components or lacking the wild-type spoVA operon. CONCLUSIONS This work indicates that the SpoVA channel encoded by Tn1546 functions like the wild-type SpoVA channel in CaDPA uptake into developing spores, but not as well in germination. The essentially identical CaDPA and water contents of spores with and without Tn1546 indicate that low core water content does not cause elevated wet heat resistance of spores with Tn1546. SIGNIFICANCE AND IMPACT OF THE STUDY Since wet heat resistance of spores of Bacillus species poses problems in the food industry, understanding mechanisms of spores' wet heat resistance is of significant applied interest.
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Affiliation(s)
- Y Luo
- Department of Physics, East Carolina University, Greenville, NC, USA.,Laboratory for Biomedical Photonics & Engineering, Life Sciences Institute, Guangxi Medical University, Nanning, Guangxi, P.R. China
| | - G Korza
- Department of Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - A M DeMarco
- Department of Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - O P Kuipers
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - Y-Q Li
- Department of Physics, East Carolina University, Greenville, NC, USA.,School of Electronic Engineering, Dongguan University of Technology, Dongguan, Guangdong, P.R. China
| | - P Setlow
- Department of Molecular Genetics, University of Groningen, Groningen, The Netherlands
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Evelyn, Utami SP, Chairul. Effect of temperature and soluble solid on Bacillus subtilis and Bacillus licheniformis spore inactivation and quality degradation of pineapple juice. FOOD SCI TECHNOL INT 2021; 28:285-296. [PMID: 34018829 DOI: 10.1177/10820132211019143] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bacillus subtilis and Bacillus licheniformis spores can survive processing temperatures used in the thermal processes of high-acid foods. Therefore, this study investigated the thermal inactivation of B. subtilis and B. licheniformis spores in pineapple juice at different temperatures (85-100°C) and soluble solids (SS, 11-30°Brix). The quality of juices and microbial loads after the thermal treatments during storage at 4 °C for 35 days was then checked. A linear decrease in D-value was observed with increasing temperature of treatment. Furthermore, the D-values determined in pineapple juice were: D90°C=13.2 ± 0.5 mins, D95°C = 6.8 ± 0.9 mins and D100°C = 2.1 ± 1.7 mins for B. subtilis spores, and D85°C = 16.6 ± 0.4 mins, D90°C = 7.6 ± 0.5 mins and D95°C = 3.6 ± 1.5 min, for B. licheniformis. Generally, the susceptibility of the bacteria to soluble solid change was affected by the interaction between temperature, SS and strain. In addition, pasteurization processes of ≥95°C for ≥33.8 mins was needed to ensure a recommended 5-log reduction of B. subtilis spores and limit vitamin C degradation of pineapple juice within three-week of storage at 4 °C.
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Affiliation(s)
- Evelyn
- Department of Chemical Engineering, University of Riau, Pekanbaru, Indonesia
| | - Syelvia Putri Utami
- Department of Chemical Engineering, University of Riau, Pekanbaru, Indonesia
| | - Chairul
- Department of Chemical Engineering, University of Riau, Pekanbaru, Indonesia
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DeMarco AM, Korza G, Granados MR, Mok WWK, Setlow P. Dodecylamine rapidly kills of spores of multiple Firmicute species: properties of the killed spores and the mechanism of the killing. J Appl Microbiol 2021; 131:2612-2625. [PMID: 33998749 DOI: 10.1111/jam.15137] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/28/2021] [Accepted: 05/09/2021] [Indexed: 01/07/2023]
Abstract
AIMS Previous work showed that Bacillus subtilis dormant spore killing and germination by dodecylamine take place by different mechanisms. This new work aimed to optimize killing of B. subtilis and other Firmicutes spores and to determine the mechanism of the killing. METHODS AND RESULTS Spores of seven Firmicute species were killed rapidly by dodecylamine under optimal conditions and more slowly by decylamine or tetradecylamine. The killed spores were not recovered by additions to recovery media, and some of the killed spores subsequently germinated, all indicating that dodecylamine-killed spores truly are dead. Spores of two species treated with dodecylamine were more sensitive to killing by a subsequent heat treatment, and spore killing of at least one species was faster with chemically decoated spores. The cores of dodecylamine-killed spores were stained by the nucleic acid stain propidium iodide, and dodecylamine-killed wild-type and germination-deficient spores released their stores of phosphate-containing small molecules. CONCLUSIONS This work indicates that dodecylamine is likely a universal sporicide for Firmicute species, and it kills spores by damaging their inner membrane, with attendant loss of this membrane as a permeability barrier. SIGNIFICANCE AND IMPACT OF THE STUDY There is a significant need for agents that can effectively kill spores of a number of Firmicute species, especially in wide area decontamination. Dodecylamine appears to be a universal sporicide with a novel mechanism of action, and this or some comparable molecule could be useful in wide area spore decontamination.
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Affiliation(s)
- A M DeMarco
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - G Korza
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - M R Granados
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - W W K Mok
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - P Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
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Ryu Y, Hong M, Kim SB, Lee TK, Park W. Raman spectroscopy reveals alteration of spore compositions under different nutritional conditions in Lysinibacillus boronitolerans YS11. J Microbiol 2021; 59:491-499. [PMID: 33779962 DOI: 10.1007/s12275-021-0679-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/28/2021] [Accepted: 02/08/2021] [Indexed: 01/01/2023]
Abstract
Little is known about final spores components when bacteria undergo sporulation under different nutrient conditions. Different degrees of resistance and germination rates were observed in the three types of spores of Lysinibacillus boronitolerans YS11 (SD, Spores formed in Difco sporulation medium™; SC and SF, Spores formed in an agricultural byproduct medium with 10 mM CaCl2 and with 10 mM FeSO4, respectively). Stronger UV resistance was recorded for SF with 1.8-2.3-fold greater survival than SC and SD under UV treatment. The three spore types showed similar heat resistances at 80°C, but survival rates of SC and SD were much higher (∼1,000 times) than those of SF at 90°C. However, germination capacity of SF was 20% higher than those of SD and SC on Luria-Bertani agar plates for 24 h. SF germinated more rapidly in a liquid medium with high NaCl concentrations than SC and SD, but became slower under alkaline conditions. Raman spectroscopy was used to analyze the heterogeneities in the three types of vegetative cells and their spores under different nutritional conditions. Exponentially grown-each vegetative cells had different overall Raman peak values. Raman peaks of SC, SD, and SF also showed differences in adenine and amide III compositions and nucleic acid contents. Our data along with Raman spectroscopy provided the evidence that spores formed under under different growth conditions possess very different cellular components, which affected their survival and germination rates.
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Affiliation(s)
- Youngung Ryu
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Minyoung Hong
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Soo Bin Kim
- Department of Environmental Engineering, Yonsei University, Wonju, 26493, Republic of Korea
| | - Tae Kwon Lee
- Department of Environmental Engineering, Yonsei University, Wonju, 26493, Republic of Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea.
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44
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Diallo M, Kengen SWM, López-Contreras AM. Sporulation in solventogenic and acetogenic clostridia. Appl Microbiol Biotechnol 2021; 105:3533-3557. [PMID: 33900426 PMCID: PMC8102284 DOI: 10.1007/s00253-021-11289-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/03/2021] [Accepted: 04/07/2021] [Indexed: 02/07/2023]
Abstract
The Clostridium genus harbors compelling organisms for biotechnological production processes; while acetogenic clostridia can fix C1-compounds to produce acetate and ethanol, solventogenic clostridia can utilize a wide range of carbon sources to produce commercially valuable carboxylic acids, alcohols, and ketones by fermentation. Despite their potential, the conversion by these bacteria of carbohydrates or C1 compounds to alcohols is not cost-effective enough to result in economically viable processes. Engineering solventogenic clostridia by impairing sporulation is one of the investigated approaches to improve solvent productivity. Sporulation is a cell differentiation process triggered in bacteria in response to exposure to environmental stressors. The generated spores are metabolically inactive but resistant to harsh conditions (UV, chemicals, heat, oxygen). In Firmicutes, sporulation has been mainly studied in bacilli and pathogenic clostridia, and our knowledge of sporulation in solvent-producing or acetogenic clostridia is limited. Still, sporulation is an integral part of the cellular physiology of clostridia; thus, understanding the regulation of sporulation and its connection to solvent production may give clues to improve the performance of solventogenic clostridia. This review aims to provide an overview of the triggers, characteristics, and regulatory mechanism of sporulation in solventogenic clostridia. Those are further compared to the current knowledge on sporulation in the industrially relevant acetogenic clostridia. Finally, the potential applications of spores for process improvement are discussed.Key Points• The regulatory network governing sporulation initiation varies in solventogenic clostridia.• Media composition and cell density are the main triggers of sporulation.• Spores can be used to improve the fermentation process.
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Affiliation(s)
- Mamou Diallo
- Wageningen Food and Biobased Research, Wageningen, The Netherlands.
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, The Netherlands.
| | - Servé W M Kengen
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, The Netherlands
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45
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Koo TM, Ko MJ, Park BC, Kim MS, Kim YK. Fluorescent detection of dipicolinic acid as a biomarker in bacterial spores employing terbium ion-coordinated magnetite nanoparticles. JOURNAL OF HAZARDOUS MATERIALS 2021; 408:124870. [PMID: 33387720 DOI: 10.1016/j.jhazmat.2020.124870] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 12/04/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
Anthrax is a bioterror agent because of its toxicity and the tolerance of its bacterial spores. Thus, researchers have attempted to develop various nanomaterials to detect dipicolinic acid (DPA), a biomarker of bacterial spores. Nanomaterials containing lanthanide ions have received considerable attention, owing to their potential to exhibit high sensitivity and selectivity in the detection of DPA via chelation with molecules. However, the fluorescent signals of the lanthanide complex are quenchable because the nanomaterials simultaneously absorb the excitation and emission light. For the precise detection of DPA, pure signals have to be obtained from the complex by alleviating the quenching effect of the nanomaterials. In this study, we develop a structure with terbium ion (Tb3+)-coordinated magnetite (Fe3O4) nanoparticle to detect DPA. Tb3+ can be detached from the magnetite during chelation with the DPA, and the complex can emit the unencumbered signals with improved detection limit through the application of a magnetic field. The detection system exhibits a significantly lower detection limit (5.4 nM) than the infectious dosage of anthrax (60 μM) with high selectivity and chemical stability. This study informs the improvement of detection limits via the separation of nanomaterials and lanthanide complex.
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Affiliation(s)
- Thomas Myeongseok Koo
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Min Jun Ko
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Bum Chul Park
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea; Brain Korea Center for Smart Materials and Devices, Korea University, Seoul 02841, Republic of Korea
| | - Myeong Soo Kim
- Institute for High Technology Materials and Devices, Korea University, Seoul 02841, Republic of Korea
| | - Young Keun Kim
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea; Brain Korea Center for Smart Materials and Devices, Korea University, Seoul 02841, Republic of Korea; Institute for High Technology Materials and Devices, Korea University, Seoul 02841, Republic of Korea.
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46
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Baker BR, Ives CM, Bray A, Caffrey M, Cochrane SA. Undecaprenol kinase: Function, mechanism and substrate specificity of a potential antibiotic target. Eur J Med Chem 2020; 210:113062. [PMID: 33310291 DOI: 10.1016/j.ejmech.2020.113062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 10/22/2022]
Abstract
The bifunctional undecaprenol kinase/phosphatase (UdpK) is a small, prokaryotic, integral membrane kinase, homologous with Escherichia coli diacylglycerol kinase and expressed by the dgkA gene. In Gram-positive bacteria, UdpK is involved in the homeostasis of the bacterial undecaprenoid pool, where it converts undecaprenol to undecaprenyl phosphate (C55P) and also catalyses the reverse process. C55P is the universal lipid carrier and critical to numerous glycopolymer and glycoprotein biosynthetic pathways in bacteria. DgkA gene expression has been linked to facilitating bacterial growth and survival in response to environmental stressors, as well being implicated as a resistance mechanism to the topical antibiotic bacitracin, by providing an additional route to C55P. Therefore, identification of UdpK inhibitors could lead to novel antibiotic treatments. A combination of homology modelling and mutagenesis experiments on UdpK have been used to identify residues that may be involved in kinase/phosphatase activity. In this review, we will summarise recent work on the mechanism and substrate specificity of UdpK.
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Affiliation(s)
- Brad R Baker
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Callum M Ives
- School of Medicine and School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160, Pearse Street, Dublin 2, D02 R590, Ireland; Division of Computational Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Ashley Bray
- School of Medicine and School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160, Pearse Street, Dublin 2, D02 R590, Ireland
| | - Martin Caffrey
- School of Medicine and School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160, Pearse Street, Dublin 2, D02 R590, Ireland.
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK.
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Lalla SJ, Kaneshige KR, Miller DR, Mackelprang R, Mogul R. Quantification of endospores in ancient permafrost using time-resolved terbium luminescence. Anal Biochem 2020; 612:113957. [PMID: 32961249 DOI: 10.1016/j.ab.2020.113957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 09/11/2020] [Accepted: 09/13/2020] [Indexed: 11/28/2022]
Abstract
We describe herein a simple procedure for quantifying endospore abundances in ancient and organic-rich permafrost. We repeatedly (10x) extracted and fractionated permafrost using a tandem filter assembly composed of 3 and 0.2 μm filters. Then, the 0.2 μm filter was washed (7x), autoclaved, and the contents eluted, including dipicolinic acid (DPA). Time-resolved luminescence using Tb(EDTA) yielded a LOD of 1.46 nM DPA (6.55 × 103 endospores/mL). In review, DPA/endospore abundances were ~2.2-fold greater in older 33 ky permafrost (258 ± 36 pmol DPA gdw-1; 1.15 × 106 ± 0.16 × 106 spores gdw-1) versus younger 19 ky permafrost (p = 0.007297). This suggests that dormancy increases with permafrost age.
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Affiliation(s)
- S J Lalla
- Chemistry & Biochemistry Department, Cal Poly Pomona, Pomona, CA, 91768, USA
| | - K R Kaneshige
- Chemistry & Biochemistry Department, Cal Poly Pomona, Pomona, CA, 91768, USA
| | - D R Miller
- Chemistry & Biochemistry Department, Cal Poly Pomona, Pomona, CA, 91768, USA
| | - R Mackelprang
- Department of Biological Sciences, CSU Northridge, Northridge, CA, USA
| | - R Mogul
- Chemistry & Biochemistry Department, Cal Poly Pomona, Pomona, CA, 91768, USA.
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48
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Brunt J, van Vliet AHM, Carter AT, Stringer SC, Amar C, Grant KA, Godbole G, Peck MW. Diversity of the Genomes and Neurotoxins of Strains of Clostridium botulinum Group I and Clostridium sporogenes Associated with Foodborne, Infant and Wound Botulism. Toxins (Basel) 2020; 12:toxins12090586. [PMID: 32932818 PMCID: PMC7551954 DOI: 10.3390/toxins12090586] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/02/2020] [Accepted: 09/08/2020] [Indexed: 12/23/2022] Open
Abstract
Clostridium botulinum Group I and Clostridium sporogenes are closely related bacteria responsible for foodborne, infant and wound botulism. A comparative genomic study with 556 highly diverse strains of C. botulinum Group I and C. sporogenes (including 417 newly sequenced strains) has been carried out to characterise the genetic diversity and spread of these bacteria and their neurotoxin genes. Core genome single-nucleotide polymorphism (SNP) analysis revealed two major lineages; C. botulinum Group I (most strains possessed botulinum neurotoxin gene(s) of types A, B and/or F) and C. sporogenes (some strains possessed a type B botulinum neurotoxin gene). Both lineages contained strains responsible for foodborne, infant and wound botulism. A new C. sporogenes cluster was identified that included five strains with a gene encoding botulinum neurotoxin sub-type B1. There was significant evidence of horizontal transfer of botulinum neurotoxin genes between distantly related bacteria. Population structure/diversity have been characterised, and novel associations discovered between whole genome lineage, botulinum neurotoxin sub-type variant, epidemiological links to foodborne, infant and wound botulism, and geographic origin. The impact of genomic and physiological variability on the botulism risk has been assessed. The genome sequences are a valuable resource for future research (e.g., pathogen biology, evolution of C. botulinum and its neurotoxin genes, improved pathogen detection and discrimination), and support enhanced risk assessments and the prevention of botulism.
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Affiliation(s)
- Jason Brunt
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (A.T.C.); (S.C.S.)
- Correspondence: (J.B.); (M.W.P.)
| | - Arnoud H. M. van Vliet
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, UK;
| | - Andrew T. Carter
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (A.T.C.); (S.C.S.)
| | - Sandra C. Stringer
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (A.T.C.); (S.C.S.)
| | - Corinne Amar
- Gastrointestinal Pathogens Unit, National Infection Service, Public Health England, London NW9 5EQ, UK; (C.A.); (K.A.G.); (G.G.)
| | - Kathie A. Grant
- Gastrointestinal Pathogens Unit, National Infection Service, Public Health England, London NW9 5EQ, UK; (C.A.); (K.A.G.); (G.G.)
| | - Gauri Godbole
- Gastrointestinal Pathogens Unit, National Infection Service, Public Health England, London NW9 5EQ, UK; (C.A.); (K.A.G.); (G.G.)
| | - Michael W. Peck
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (A.T.C.); (S.C.S.)
- Correspondence: (J.B.); (M.W.P.)
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Mokashi S, Kanaan J, Craft D, Byrd B, Zenick B, Laue M, Korza G, Mok W, Setlow P. Killing of bacterial spores by dodecylamine and its effects on spore inner membrane properties. J Appl Microbiol 2020; 129:1511-1522. [DOI: 10.1111/jam.14732] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/30/2020] [Accepted: 05/26/2020] [Indexed: 11/29/2022]
Affiliation(s)
- S. Mokashi
- Department of Molecular Biology and Biophysics UConn Health Farmington CT USA
| | - J. Kanaan
- Department of Molecular Biology and Biophysics UConn Health Farmington CT USA
| | - D.L. Craft
- Department of Molecular Biology and Biophysics UConn Health Farmington CT USA
| | - B. Byrd
- Department of Molecular Biology and Biophysics UConn Health Farmington CT USA
| | - B. Zenick
- Department of Molecular Biology and Biophysics UConn Health Farmington CT USA
| | - M. Laue
- Advanced Light and Electron Microscopy (ZBS 4) Robert Koch Institute Berlin Germany
| | - G. Korza
- Department of Molecular Biology and Biophysics UConn Health Farmington CT USA
| | - W.W.K. Mok
- Department of Molecular Biology and Biophysics UConn Health Farmington CT USA
| | - P. Setlow
- Department of Molecular Biology and Biophysics UConn Health Farmington CT USA
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50
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The molecular dynamics of bacterial spore and the role of calcium dipicolinate in core properties at the sub-nanosecond time-scale. Sci Rep 2020; 10:8265. [PMID: 32427943 PMCID: PMC7237433 DOI: 10.1038/s41598-020-65093-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/21/2020] [Indexed: 11/18/2022] Open
Abstract
Bacterial spores are among the most resistant forms of life on Earth. Their exceptional resistance properties rely on various strategies, among them the core singular structure, organization and hydration. By using elastic incoherent neutron scattering, we probed the dynamics of Bacillus subtilis spores to determine whether core macromolecular motions at the sub-nanosecond timescale could also contribute to their resistance to physical stresses. In addition, in order to better specify the role of the various spore components, we used different mutants lacking essential structure such as the coat (PS4150 mutant), or the calcium dipicolinic acid complex (CaDPA) located in the core (FB122 mutant). PS4150 allows to better probe the core’s dynamics, as proteins of the coat represent an important part of spore proteins, and FB122 gives information about the role of the large CaDPA depot for the mobility of core’s components. We show that core’s macromolecular mobility is not particularly constrained at the sub-nanosecond timescale in spite of its low water content as some dynamical characteristics as force constants are very close to those of vegetative bacteria such as Escherichia coli or to those of fully hydrated proteins. Although the force constants of the coatless mutant are similar to the wild-type’s ones, it has lower mean square displacements (MSDs) at high Q showing that core macromolecules are somewhat more constrained than the rest of spore components. However, no behavior reflecting the glassy state regularly evoked in the literature could be drawn from our data. As hydration and macromolecules’ mobility are highly correlated, the previous assumption, that core low water content might explain spores’ exceptional resistance properties seems unlikely. Thus, we confirm recent theories, suggesting that core water is mostly as free as bulk water and proteins/macromolecules are fully hydrated. The germination of spores leads to a much less stable system with a force constant of 0.1 N/m and MSDs ~2.5 times higher at low Q than in the dormant state. DPA has also an influence on core mobility with a slightly lower force constant for the DPA-less mutant than for the wild-type, and MSDs that are ~ 1.8 times higher on average than for the wild-type at low Q. At high Q, germinated and DPA-less spores were very similar to the wild-type ones, showing that DPA and core compact structure might influence large amplitude motions rather than local dynamics of macromolecules.
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