1
|
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.
Collapse
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..
| |
Collapse
|
2
|
Zhou Q, Li G, Cui Y, Xiang J, Zhu S, Li S, Huang J, Wang Y, Liu Y, Zhou L. Genomic characterization of Bacillus cereus isolated from food poisoning cases revealed the mechanism of toxin production. Front Microbiol 2024; 14:1238799. [PMID: 38282728 PMCID: PMC10822677 DOI: 10.3389/fmicb.2023.1238799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 12/12/2023] [Indexed: 01/30/2024] Open
Abstract
Introduction Bacillus cereus is a ubiquitous opportunistic human pathogen that causes food intoxications worldwide. However, the genomic characteristics and pathogenic mechanisms of B. cereus are still unclear. Methods Here, we isolated and purified nine strains of B. cereus (LY01-LY09) that caused vomiting, diarrhea and other symptoms from four foodborne outbreaks happened in Guizhou Province in southwest China from June to September 2021. After colony observation, Gram staining, microscopic examination and biochemical test, they were identified as B. cereus. The genomic characteristics, phylogenetic relationships and virulence factors of the isolated strains were analyzed at the genome level. Genome sequencing, comparative genomic analysis, secondary metabolite analysis and quantitative PCR were utilized to give a thorough exploration of the strains. Results We obtained the genome maps of LY01-LY09 and found that LY01-LY09 had a complex interspecific relationship with B. anthracis and B. thuringiensis. We also observed a contraction of gene families in LY01-LY09, and the contracted families were mainly associated with prophage, which contributed to the species diversity of B. cereus. The Hsp20 gene family underwent a rapid evolution in LY01-LY09, which facilitated the adaptation of the strains to adverse environmental conditions. Moreover, the LY01-LY09 strains exhibited a higher copy number in the non-ribosomal polypeptide synthetase (NRPS) genes and carried the complete cereulide synthetase (ces) gene cluster sequences. Considering that the NRPS system is a classical regulatory mechanism for emetic toxin synthesis, we hypothesized that LY01-LY09 could synthesize emetic toxins through the regulation of ces gene clusters by the NRPS system. Discussion These findings are important for further investigation into the evolutionary relationship between B. cereus and their related species, as well as the underlying mechanisms governing the synthesis and secretion of bacterial toxins.
Collapse
Affiliation(s)
- Qian Zhou
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Guanqiao Li
- College of Bioinformatics, Chongqing University of Post and Telecommunications, Chongqing, China
| | - Yinshan Cui
- Yunnan Pulis Biotechnology Co., Ltd., Kunming, Yunnan, China
| | - Jingshu Xiang
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Shu Zhu
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Shijun Li
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Jingyu Huang
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Yafang Wang
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Ying Liu
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| | - Li Zhou
- Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, Guizhou, China
| |
Collapse
|
3
|
Broussolle V, Gohar M, Slamti L, Tournier JN. Insights into the Bacillus anthracis, cereus and thuringiensis world through the BACT conference. Res Microbiol 2023; 174:104095. [PMID: 37399933 DOI: 10.1016/j.resmic.2023.104095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/05/2023]
Affiliation(s)
- V Broussolle
- INRAE, Avignon Université, UMR SQPOV, Avignon, France
| | - M Gohar
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - L Slamti
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France.
| | | |
Collapse
|