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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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Keshri J, Smith KM, Svendsen MK, Keillor HR, Moss ML, Jordan HJ, Larkin AM, Garrish JK, Line JE, Ball PN, Oakley BB, Seal BS. Phenotypic Characterization and Draft Genome Sequence Analyses of Two Novel Endospore-Forming Sporosarcina spp. Isolated from Canada Goose ( Branta canadensis) Feces. Microorganisms 2023; 12:70. [PMID: 38257897 PMCID: PMC10818898 DOI: 10.3390/microorganisms12010070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 12/15/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
In an attempt to isolate new probiotic bacteria, two Gram-variable, spore-forming, rod-shaped aerobic bacteria designated as strain A4 and A15 were isolated from the feces of Canada geese (Branta canadensis). Strain A4 was able to grow in high salt levels and exhibited lipase activity, while A15 did not propagate under these conditions. Both were positive for starch hydrolysis, and they inhibited the growth of Staphylococcus aureus. The strains of the 16S rRNA sequence shared only 94% similarity to previously identified Sporosarcina spp. The ANI (78.08%) and AAI (82.35%) between the two strains were less than the species threshold. Searches for the most similar genomes using the Mash/Minhash algorithm showed the nearest genome to strain A4 and A15 as Sporosarcina sp. P13 (distance of 21%) and S. newyorkensis (distance of 17%), respectively. Sporosarcina spp. strains A4 and A15 contain urease genes, and a fibronectin-binding protein gene indicates that these bacteria may bind to eukaryotic cells in host gastrointestinal tracts. Phenotypic and phylogenetic data, along with low dDDH, ANI, and AAI values for strains A4 and A15, indicate these bacteria are two novel isolates of the Sporosarcina genus: Sporosarcina sp. A4 sp. nov., type strain as Sporosarcina cascadiensis and Sporosarcina sp. A15 sp. nov., type strain Sporosarcina obsidiansis.
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Affiliation(s)
- Jitendra Keshri
- College of Veterinary Medicine, Western University of Health Sciences, Pomona, CA 91766, USA;
| | - Kristina M. Smith
- Biology Program, Oregon State University Cascades, Bend, OR 97702, USA; (K.M.S.); (M.K.S.); (H.R.K.); (M.L.M.); (H.J.J.); (A.M.L.); (P.N.B.)
| | - Molly K. Svendsen
- Biology Program, Oregon State University Cascades, Bend, OR 97702, USA; (K.M.S.); (M.K.S.); (H.R.K.); (M.L.M.); (H.J.J.); (A.M.L.); (P.N.B.)
| | - Haley R. Keillor
- Biology Program, Oregon State University Cascades, Bend, OR 97702, USA; (K.M.S.); (M.K.S.); (H.R.K.); (M.L.M.); (H.J.J.); (A.M.L.); (P.N.B.)
| | - Madeline L. Moss
- Biology Program, Oregon State University Cascades, Bend, OR 97702, USA; (K.M.S.); (M.K.S.); (H.R.K.); (M.L.M.); (H.J.J.); (A.M.L.); (P.N.B.)
| | - Haley J. Jordan
- Biology Program, Oregon State University Cascades, Bend, OR 97702, USA; (K.M.S.); (M.K.S.); (H.R.K.); (M.L.M.); (H.J.J.); (A.M.L.); (P.N.B.)
| | - Abigail M. Larkin
- Biology Program, Oregon State University Cascades, Bend, OR 97702, USA; (K.M.S.); (M.K.S.); (H.R.K.); (M.L.M.); (H.J.J.); (A.M.L.); (P.N.B.)
| | - Johnna K. Garrish
- Poultry Microbiological Safety & Processing Research Unit, U.S. National Poultry Research Center, Athens, GA 30605, USA; (J.K.G.); (J.E.L.)
| | - John Eric Line
- Poultry Microbiological Safety & Processing Research Unit, U.S. National Poultry Research Center, Athens, GA 30605, USA; (J.K.G.); (J.E.L.)
| | - Patrick N. Ball
- Biology Program, Oregon State University Cascades, Bend, OR 97702, USA; (K.M.S.); (M.K.S.); (H.R.K.); (M.L.M.); (H.J.J.); (A.M.L.); (P.N.B.)
| | - Brian B. Oakley
- College of Veterinary Medicine, Western University of Health Sciences, Pomona, CA 91766, USA;
| | - Bruce S. Seal
- Biology Program, Oregon State University Cascades, Bend, OR 97702, USA; (K.M.S.); (M.K.S.); (H.R.K.); (M.L.M.); (H.J.J.); (A.M.L.); (P.N.B.)
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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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Moir A, Christie G. A coating of lipoproteins provides a stabilizing environment on the inner membrane of Bacillus subtilis spores. J Bacteriol 2023; 205:e0016723. [PMID: 37730539 PMCID: PMC10601610 DOI: 10.1128/jb.00167-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023] Open
Abstract
A new study by M. J. Flores, K. Duricy, S. Choudhary, M. Laue, and D. L. Popham (J Bacteriol 205:e00142-23, 2023, https://doi.org/10.1128/jb.00142-23) demonstrates a role for the YlaJ/YhcN family of lipoproteins in the immobilization of the spore's inner membrane. In the absence of these lipoproteins, membrane fluidity increases and membrane-associated proteins like the GerA receptor complexes are more exposed to inimical conditions. The role of these proteins in stabilizing the Bacillus spore inner membrane is now being explored.
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Affiliation(s)
- Anne Moir
- School of Biosciences, University of Sheffield, Firth Court, Sheffield, United Kingdom
| | - Graham Christie
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
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