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Vater J, Tam LTT, Jähne J, Herfort S, Blumenscheit C, Schneider A, Luong PT, Thao LTP, Blom J, Klee SR, Schweder T, Lasch P, Borriss R. Plant-Associated Representatives of the Bacillus cereus Group Are a Rich Source of Antimicrobial Compounds. Microorganisms 2023; 11:2677. [PMID: 38004689 PMCID: PMC10672896 DOI: 10.3390/microorganisms11112677] [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: 10/08/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 11/26/2023] Open
Abstract
Seventeen bacterial strains able to suppress plant pathogens have been isolated from healthy Vietnamese crop plants and taxonomically assigned as members of the Bacillus cereus group. In order to prove their potential as biocontrol agents, we perform a comprehensive analysis that included the whole-genome sequencing of selected strains and the mining for genes and gene clusters involved in the synthesis of endo- and exotoxins and secondary metabolites, such as antimicrobial peptides (AMPs). Kurstakin, thumolycin, and other AMPs were detected and characterized by different mass spectrometric methods, such as MALDI-TOF-MS and LIFT-MALDI-TOF/TOF fragment analysis. Based on their whole-genome sequences, the plant-associated isolates were assigned to the following species and subspecies: B. cereus subsp. cereus (6), B. cereus subsp. bombysepticus (5), Bacillus tropicus (2), and Bacillus pacificus. These three isolates represent novel genomospecies. Genes encoding entomopathogenic crystal and vegetative proteins were detected in B. cereus subsp. bombysepticus TK1. The in vitro assays revealed that many plant-associated isolates enhanced plant growth and suppressed plant pathogens. Our findings indicate that the plant-associated representatives of the B. cereus group are a rich source of putative antimicrobial compounds with potential in sustainable agriculture. However, the presence of virulence genes might restrict their application as biologicals in agriculture.
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Affiliation(s)
- Joachim Vater
- Proteomics and Spectroscopy Unit (ZBS6), Center for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (J.V.); (J.J.); (S.H.); (C.B.); (A.S.); (P.L.)
| | - Le Thi Thanh Tam
- Division of Pathology and Phyto-Immunology, Plant Protection Research Institute (PPRI), Duc Thang, Bac Tu Liem, Hanoi, Vietnam; (L.T.T.T.); (P.T.L.); (L.T.P.T.)
| | - Jennifer Jähne
- Proteomics and Spectroscopy Unit (ZBS6), Center for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (J.V.); (J.J.); (S.H.); (C.B.); (A.S.); (P.L.)
| | - Stefanie Herfort
- Proteomics and Spectroscopy Unit (ZBS6), Center for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (J.V.); (J.J.); (S.H.); (C.B.); (A.S.); (P.L.)
| | - Christian Blumenscheit
- Proteomics and Spectroscopy Unit (ZBS6), Center for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (J.V.); (J.J.); (S.H.); (C.B.); (A.S.); (P.L.)
| | - Andy Schneider
- Proteomics and Spectroscopy Unit (ZBS6), Center for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (J.V.); (J.J.); (S.H.); (C.B.); (A.S.); (P.L.)
| | - Pham Thi Luong
- Division of Pathology and Phyto-Immunology, Plant Protection Research Institute (PPRI), Duc Thang, Bac Tu Liem, Hanoi, Vietnam; (L.T.T.T.); (P.T.L.); (L.T.P.T.)
| | - Le Thi Phuong Thao
- Division of Pathology and Phyto-Immunology, Plant Protection Research Institute (PPRI), Duc Thang, Bac Tu Liem, Hanoi, Vietnam; (L.T.T.T.); (P.T.L.); (L.T.P.T.)
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig Universität Giessen, 35392 Giessen, Germany;
| | - Silke R. Klee
- Highly Pathogenic Microorganisms Unit (ZBS2), Center for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany;
| | - Thomas Schweder
- Institute of Marine Biotechnology e.V. (IMaB), 17489 Greifswald, Germany;
- Pharmaceutical Biotechnology, University of Greifswald, 17489 Greifswald, Germany
| | - Peter Lasch
- Proteomics and Spectroscopy Unit (ZBS6), Center for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (J.V.); (J.J.); (S.H.); (C.B.); (A.S.); (P.L.)
| | - Rainer Borriss
- Institute of Marine Biotechnology e.V. (IMaB), 17489 Greifswald, Germany;
- Institute of Biology, Humboldt University Berlin, 10115 Berlin, Germany
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2
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Zhou H, Zhang J, Shao Y, Wang J, Xu W, Liu Y, Yu S, Ye Q, Pang R, Wu S, Gu Q, Xue L, Zhang J, Li H, Wu Q, Ding Y. Development of a high resolution melting method based on a novel molecular target for discrimination between Bacillus cereus and Bacillus thuringiensis. Food Res Int 2022; 151:110845. [PMID: 34980383 DOI: 10.1016/j.foodres.2021.110845] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 11/03/2021] [Accepted: 11/27/2021] [Indexed: 11/04/2022]
Abstract
Delimitation within the Bacillus cereus group is confusing due to the highly similar genetic background of its constituent bacteria. This study aimed to develop a rapid and efficient method for the identification of Bacillus cereus and Bacillus thuringiensis, two closely related species within the B. cereus group. Using average nucleotide identity analysis (ANI) and ribosomal multilocus sequence typing (rMLST), the authenticity of the genomes of B. cereus and B. thuringiensis was determined. Emetic B. cereus and Bacillus bombysepticus were also included to provide novel genomic insights into the boundaries within the B. cereus group. Using pan-genome analysis, ispD, a novel core and single-copy molecular target, was identified for the differentiation between B. cereus and B. thuringiensis. Based on the single nucleotide polymorphism within ispD, a high resolution melting (HRM) method for the determination of B. cereus and B. thuringiensis was developed. This method can not only distinguish B. cereus and B. thuringiensis, but can also separate B. cereus from other foodborne pathogenic bacteria. The detection limit of this method could reach 1 pg of pure genomic DNA and 3.7 × 102 cfu/mL of pure culture. Moreover, this new method could effectively differentiate B. cereus and B. thuringiensis in spiked, mixed, and real food samples. Collectively, the established HRM method can provide a new reference paradigm for the sensitive and specific nucleic acid detection of pathogens with identical genomes.
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Affiliation(s)
- Huan Zhou
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Junhui Zhang
- Department of Food Science & Technology, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Yanna Shao
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Department of Food Science & Technology, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou 510432, China
| | - Wenxing Xu
- Department of Food Science & Technology, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Yang Liu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Shubo Yu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Qinghua Ye
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Rui Pang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Shi Wu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Qihui Gu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Liang Xue
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Jumei Zhang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Hongye Li
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Qingping Wu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Yu Ding
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Department of Food Science & Technology, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China.
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3
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Ge Q, Cao W, Zhu F, Yuan Y, Chen L, Xu J, Li J, Chen H, Ma S, Sun L, Pan H, Taha RH, Yao Q, Chen K. Genomics and proteomics combined analysis revealed the toxicity response of silkworm Bombyx mori to the environmental pathogen Bacillus cereus ZJ-4. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 222:112467. [PMID: 34217115 DOI: 10.1016/j.ecoenv.2021.112467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
Bacterial contamination has caused a major public health problem worldwide. Bacillus cereus is a conditional environmental pathogenic bacteria that can cause food poisoning. Whether environmental pathogens can cause widespread transmission in the insect kingdom is unclear. In this study, a Bacillus cereus ZJ-4 was isolated from the hospital environment of Zhenjiang City, Jiangsu Province, China. It was fatal by injection into the silkworm hemolymph. To investigated the potential toxic factors of ZJ-4 and clarified the toxicity response mechanism of silkworm by the ZJ-4 infection. Then, the whole genome of ZJ-4 was sequenced, and the immune mechanism of silkworm fat body to ZJ-4 pathogen was studied by HE pathological section and proteomics. Bacterial genome sequencing indicated that ZJ-4 had 352 drug resistance genes and 6 virulence genes. After 36 h of subcutaneous puncture with ZJ-4 suspension, the pathological changes were obviously found in HE pathological sections of fat body tissue. Comparative proteomic results indicated that differentially expressed proteins are mainly involved in stress reactions, biological regulation, and innate immunity. The qRT-PCR analysis showed that the expressions of β-GRP, Spaetzle, MyD88, Tube and Dorsal genes in Toll pathway were up-regulated, while Pell and Cactus genes were down-regulated; in the antimicrobial peptide pathway, Glv2, Lzm, Mor, and Leb3 genes were up-regulated, while attacin1 and defensin genes were down-regulated; Sod gene was up-regulated, while Cat gene was down-regulated in the antioxidant pathway; Ldh, Sdh, and Mdh genes were down-regulated in glucose metabolism pathway. These results indicated that ZJ-4 can damage the innate immune pathway of silkworm, and also affect the normal immune function of fat body cells.
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Affiliation(s)
- Qi Ge
- School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China; School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Weiping Cao
- The Fourth People's Hospital of Zhenjiang, Zhenjiang, Jiangsu 212001, PR China
| | - Feifei Zhu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Yi Yuan
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Liang Chen
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Jia Xu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Jun Li
- Instrumental Analysis and Testing Center, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Han Chen
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Shangshang Ma
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Lindan Sun
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Huiwen Pan
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China; Zhenjiang First People's Hospital, Zhenjiang, Jiangsu 212002, PR China
| | - Rehab Hosny Taha
- Plant Protection Research Institute, Agricultural Research Center, Egypt
| | - Qin Yao
- School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China; School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Keping Chen
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China.
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Khurana H, Sharma M, Verma H, Lopes BS, Lal R, Negi RK. Genomic insights into the phylogeny of Bacillus strains and elucidation of their secondary metabolic potential. Genomics 2020; 112:3191-3200. [PMID: 32512145 DOI: 10.1016/j.ygeno.2020.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 05/17/2020] [Accepted: 06/02/2020] [Indexed: 12/16/2022]
Abstract
The genus Bacillus constitutes a plethora of species that have medical, environmental, and industrial applications. While genus Bacillus has been the focus of several studies where genomic data have been used to resolve many taxonomic issues, there still exist several ambiguities. Through the use of in-silico genome-based methods, we tried to resolve the taxonomic anomalies of a large set of Bacillus genomes (n = 178). We also proposed species names for uncharacterized strains and reported genome sequence of a novel isolate Bacillus sp. RL. In the hierarchical clustering on genome-to-genome distances, we observed 11 distinct monophyletic clusters and investigated the functional pathways annotated as the property of these clusters and core-gene content of the entire dataset. Thus, we were able to assert the possible outlier strains (n = 17) for this genus. Analyses of secondary metabolite potential of each strain helped us unravel still unexplored diversity for various biosynthetic genes.
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Affiliation(s)
- Himani Khurana
- Fish Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi 110007, India
| | - Monika Sharma
- Fish Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi 110007, India
| | - Helianthous Verma
- Molecular Biology and Genomics Research Laboratory, Ramjas College, University of Delhi, Delhi 110007, India
| | - Bruno Silvester Lopes
- School of Medicine, Medical Sciences and Nutrition, Medical Microbiology, 0:025 Polwarth Building, Aberdeen AB25 2ZD, UK
| | - Rup Lal
- The Energy and Resources Institute, Darbari Seth Block, IHC Complex, Lodhi Road, New Delhi 110003, India.
| | - Ram Krishan Negi
- Fish Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi 110007, India.
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Drewnowska JM, Stefanska N, Czerniecka M, Zambrowski G, Swiecicka I. Potential Enterotoxicity of Phylogenetically Diverse Bacillus cereus Sensu Lato Soil Isolates from Different Geographical Locations. Appl Environ Microbiol 2020; 86:e03032-19. [PMID: 32220844 PMCID: PMC7237779 DOI: 10.1128/aem.03032-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 03/20/2020] [Indexed: 02/06/2023] Open
Abstract
Bacillus cereus sensu lato comprises Gram-positive spore-forming bacteria producing toxins associated with foodborne diseases. Three pore-forming enterotoxins, nonhemolytic enterotoxin (Nhe), hemolysin BL (Hbl), and cytotoxin K (CytK), are considered the primary factors in B. cereus sensu lato diarrhea. The aim of this study was to determine the potential risk of enterotoxicity among soil B. cereus sensu lato isolates representing diverse phylogroups and originated from different geographic locations with various climates (Burkina Faso, Kenya, Argentina, Kazakhstan, and Poland). While nheA- and hblA-positive isolates were present among all B. cereus sensu lato populations and distributed across all phylogenetic groups, cytK-2-positive strains predominated in geographic regions with an arid hot climate (Africa) and clustered together on a phylogenetic tree mainly within mesophilic groups III and IV. The highest in vitro cytotoxicity to Caco-2 and HeLa cells was demonstrated by the strains clustered within phylogroups II and IV. Overall, our results suggest that B. cereus sensu lato pathogenicity is a comprehensive process conditioned by many intracellular factors and diverse environmental conditions.IMPORTANCE This research offers a new route for a wider understanding of the dependency between pathogenicity and phylogeny of a natural bacterial population, specifically within Bacillus cereus sensu lato, that is widely distributed around the world and easily transferred into food products. Our study indicates differences in the phylogenetic and geographical distributions of potential enterotoxigenic B. cereus sensu lato strains. Hence, these bacilli possess a risk for human health, and rapid testing methods for their identification are greatly needed. In particular, the detection of the CytK enterotoxin should be a supporting strategy for the identification of pathogenic B. cereus sensu lato.
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Affiliation(s)
| | - Natalia Stefanska
- Department of Microbiology, Faculty of Biology, University of Bialystok, Bialystok, Poland
| | - Magdalena Czerniecka
- Department of Cytobiochemistry, Faculty of Biology, University of Bialystok, Bialystok, Poland
- Laboratory of Tissue Culture, Faculty of Biology, University of Bialystok, Bialystok, Poland
| | - Grzegorz Zambrowski
- Laboratory of Applied Microbiology, University of Bialystok, Bialystok, Poland
| | - Izabela Swiecicka
- Department of Microbiology, Faculty of Biology, University of Bialystok, Bialystok, Poland
- Laboratory of Applied Microbiology, University of Bialystok, Bialystok, Poland
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Phylogenetic Analysis of Bacillus cereus sensu lato Isolates from Commercial Bee Pollen Using tRNA Cys-PCR. Microorganisms 2020; 8:microorganisms8040524. [PMID: 32268545 PMCID: PMC7232370 DOI: 10.3390/microorganisms8040524] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/25/2020] [Accepted: 04/03/2020] [Indexed: 01/06/2023] Open
Abstract
Endospore-forming bacteria related to the Bacillus cereus group produce toxins that cause illnesses in organisms from invertebrates to mammals, including foodborne illnesses in humans. As commercial bee pollen can be contaminated with these bacteria, a comprehensive microbiological risk assessment of commercial bee pollen must be incorporated into the relevant regulatory requirements, including those that apply in Mexico. To facilitate detection of members of this group of bacteria, we have developed a PCR strategy that is based on the amplification of the single-copy tRNACys gene and specific genes associated with tRNACys to detect Bacillus cereus sensu lato (B. cereus s.l.). This tRNACys-PCR-based approach was used to examine commercial bee pollen for endospore-forming bacteria. Our analysis revealed that 3% of the endospore-forming colonies isolated from a commercial source of bee pollen were related to B. cereus s.l., and this result was corroborated by phylogenetic analysis, bacterial identification via MALDI-TOF MS, and detection of enterotoxin genes encoding the HBL and NHE complexes. The results show that the isolated colonies are closely related phylogenetically to B. cereus, B. thuringiensis, and B. bombysepticus. Our results indicate that the tRNACys-PCR, combined with other molecular tools, will be a useful approach for identifying B. cereus s.l. and will assist in controlling the spread of potential pathogens.
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8
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Gene Expression Pattern and Regulatory Network of α-Toxin Treatment in Bombyx mori. Int J Genomics 2019; 2019:7859121. [PMID: 30956974 PMCID: PMC6425383 DOI: 10.1155/2019/7859121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 01/03/2019] [Accepted: 01/20/2019] [Indexed: 11/24/2022] Open
Abstract
Bacillus bombyseptieus is a pathogen of Bombyx mori; it can cause bacterial septicemia in silkworm. One of the components of the parasporal crystal toxin of B. bombyseptieus, α-toxin, plays an important role in the process of infection in silkworm. In this study, we investigated the immune response of silkworm induced by α-toxin by using RNA-seq. We compared the changes in gene expression in the midgut, fatbody, and hemocytes of silkworm and in the B. mori embryonic cell line (BmE) after treatment with α-toxin and identified 952 differentially expressed genes and 353 differentially expressed long noncoding RNAs (lncRNAs). These regulated genes in different tissues were found to be enriched in different pathways. The upregulated genes in the midgut were mainly involved in peptidoglycan catabolic process and tyrosine kinase signaling pathway, whereas the downregulated genes were mainly involved in chitin metabolic pathways. The upregulated genes in fatbody were also involved in peptidoglycan catabolic process, but they were for a different peptidoglycan subtype. Further, genes encoding cecropins were enriched in the fatbody. The downregulated genes were mainly involved in the metabolic pathways of fundamental substances such as cellular protein metabolic process and nucleobase-containing compound metabolic process. These results suggest that α-toxin can induce various immune responses in silkworm, and further studies are warranted to understand the mechanism of α-toxin action in silkworm. Further, lncRNAs and differentially expressed genes were correlated using coexpression network analysis. Our findings revealed potential candidate genes and lncRNAs that might play important physiological functions in the immune response to α-toxins in silkworm.
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Retief L, Bennett NC, Jarvis JUM, Bastos ADS. Subterranean Mammals: Reservoirs of Infection or Overlooked Sentinels of Anthropogenic Environmental Soiling? ECOHEALTH 2017; 14:662-674. [PMID: 29094221 DOI: 10.1007/s10393-017-1281-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 07/16/2017] [Accepted: 09/18/2017] [Indexed: 06/07/2023]
Abstract
Global reports of emergent pathogens in humans have intensified efforts to identify wildlife reservoirs. Subterranean mammals, such as bathyergid mole rats, are largely overlooked, despite their high-level exposure to soil-dwelling microbes. Initial assessment of bathyergid reservoir potential was determined using a broad-range 16S rRNA PCR approach, which revealed an 83% PCR-positivity for the 234 bathyergid lung samples evaluated. The presence of the Bacillus cereus complex, a ubiquitous bacterial assemblage, containing pathogenic and zoonotic species, was confirmed through nucleotide sequencing, prior to group- and species-specific PCR sequencing. The latter allowed for enhanced placement and prevalence estimations of Bacillus in four bathyergid species sampled across a range of transformed landscapes in the Western Cape Province, South Africa. Two novel Bacillus strains (1 and 2) identified on the basis of the concatenated 16S rRNA-groEL-yeaC data set (2066 nucleotides in length), clustered with B. mycoides (ATCC 6462) and B. weihenstephanensis (WSBC 10204), within a well-supported monophyletic lineage. The levels of co-infection, evaluated with a groEL strain-specific assay, developed specifically for this purpose, were high (71%). The overall Bacillus presence of 17.95% (ranging from 0% for Georychus capensis to 45.35% for Bathyergus suillus) differed significantly between host species (χ2 = 69.643; df = 3; P < 0.05), being significantly higher in bathyergids sampled near an urban informal settlement (χ2 = 70.245; df = 3; P < 0.05). The results highlight the sentinel potential of soil-dwelling mammals for monitoring anthropogenically introduced, opportunistic pathogens and the threats they pose to vulnerable communities, particularly in the developing world.
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Affiliation(s)
- Liezl Retief
- Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Private Bag 20, Hatfield, 0028, South Africa
| | - Nigel C Bennett
- South African Research Chair of Mammal Behavioural Ecology and Physiology, Department of Zoology and Entomology, University of Pretoria, Private Bag 20, Hatfield, 0028, South Africa
| | - Jennifer U M Jarvis
- Department of Zoology, University of Cape Town, Rondebosch, Cape Town, 7700, South Africa
| | - Armanda D S Bastos
- Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Private Bag 20, Hatfield, 0028, South Africa.
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10
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Douriet-Gámez NR, Maldonado-Mendoza IE, Ibarra-Laclette E, Blom J, Calderón-Vázquez CL. Genomic Analysis of Bacillus sp. Strain B25, a Biocontrol Agent of Maize Pathogen Fusarium verticillioides. Curr Microbiol 2017; 75:247-255. [DOI: 10.1007/s00284-017-1372-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 10/10/2017] [Indexed: 11/24/2022]
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11
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Fiedoruk K, Drewnowska JM, Daniluk T, Leszczynska K, Iwaniuk P, Swiecicka I. Ribosomal background of the Bacillus cereus group thermotypes. Sci Rep 2017; 7:46430. [PMID: 28406161 PMCID: PMC5390287 DOI: 10.1038/srep46430] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/08/2017] [Indexed: 11/09/2022] Open
Abstract
In this study we reconstructed the architecture of Bacillus cereus sensu lato population based on ribosomal proteins, and identified a link between the ribosomal proteins’ variants and thermal groups (thermotypes) of the bacilli. The in silico phyloproteomic analysis of 55 ribosomal proteins (34 large and 21 small subunit r-proteins) of 421 strains, representing 14 well-established or plausible B. cereus sensu lato species, revealed several ribosomal clusters (r-clusters), which in general were well correlated with the strains’ affiliation to phylogenetic/thermal groups I–VII. However, a conformity and possibly a thermal characteristic of certain phylogenetic groups, e.g. the group IV, were not supported by a distribution of the corresponding r-clusters, and consequently neither by the analysis of cold-shock proteins (CSPs) nor by a content of heat shock proteins (HSPs). Furthermore, a preference for isoleucine and serine over valine and alanine in r-proteins along with a lack of HSP16.4 were recognized in non-mesophilic thermotypes. In conclusion, we suggest that the observed divergence in ribosomal proteins may be connected with an adaptation of B. cereus sensu lato members to various thermal niches.
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Affiliation(s)
- Krzysztof Fiedoruk
- Department of Microbiology, Medical University of Bialystok, Bialystok, Poland
| | - Justyna M Drewnowska
- Department of Microbiology, Institute of Biology, University of Bialystok, Bialystok, Poland
| | - Tamara Daniluk
- Department of Microbiology, Medical University of Bialystok, Bialystok, Poland
| | | | - Piotr Iwaniuk
- Department of Microbiology, Institute of Biology, University of Bialystok, Bialystok, Poland
| | - Izabela Swiecicka
- Department of Microbiology, Institute of Biology, University of Bialystok, Bialystok, Poland.,Laboratory of Applied Microbiology, University of Bialystok, Bialystok, Poland
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Abstract
We report here the complete annotated 6,035,547-bp draft genome sequence of Bacillus thuringiensis INTA Fr7-4. This strain contains three cry8 and two vip1 and vip2 insecticidal toxin genes.
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Bacillus bombysepticus α-Toxin Binding to G Protein-Coupled Receptor Kinase 2 Regulates cAMP/PKA Signaling Pathway to Induce Host Death. PLoS Pathog 2016; 12:e1005527. [PMID: 27022742 PMCID: PMC4811588 DOI: 10.1371/journal.ppat.1005527] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 03/04/2016] [Indexed: 02/06/2023] Open
Abstract
Bacterial pathogens and their toxins target host receptors, leading to aberrant behavior or host death by changing signaling events through subversion of host intracellular cAMP level. This is an efficient and widespread mechanism of microbial pathogenesis. Previous studies describe toxins that increase cAMP in host cells, resulting in death through G protein-coupled receptor (GPCR) signaling pathways by influencing adenylyl cyclase or G protein activity. G protein-coupled receptor kinase 2 (GRK2) has a central role in regulation of GPCR desensitization. However, little information is available about the pathogenic mechanisms of toxins associated with GRK2. Here, we reported a new bacterial toxin-Bacillus bombysepticus (Bb) α-toxin that was lethal to host. We showed that Bb α-toxin interacted with BmGRK2. The data demonstrated that Bb α-toxin directly bound to BmGRK2 to promote death by affecting GPCR signaling pathways. This mechanism involved stimulation of Gαs, increase level of cAMP and activation of protein kinase A (PKA). Activated cAMP/PKA signal transduction altered downstream effectors that affected homeostasis and fundamental biological processes, disturbing the structural and functional integrity of cells, resulting in death. Preventing cAMP/PKA signaling transduction by inhibitions (NF449 or H-89) substantially reduced the pathogenicity of Bb α-toxin. The discovery of a toxin-induced host death specifically linked to GRK2 mediated signaling pathway suggested a new model for bacterial toxin action. Characterization of host genes whose expression and function are regulated by Bb α-toxin and GRK2 will offer a deeper understanding of the pathogenesis of infectious diseases caused by pathogens that elevate cAMP. Interference with regulation of host signaling by pathogens can alter gene expression, leading to functional disarray in the host cells that causes abnormal division or death. Here, we propose a previously undescribed model for how bacterial toxins subvert host processes via interaction with GRK2 that influences cAMP/PKA signaling. Our findings provide new fundamental information about how bacterial pathogens regulate host signal transduction to cause death, which offers additional perspectives in host-pathogen systems. These findings will help to advance our understanding of bacteria pathogenic mechanism. Furthermore, these might extend to other microbial pathogenesis and assist in designing new or safer strategies against pathogens.
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Li GN, Xia XJ, Zhao HH, Sendegeya P, Zhu Y. Identification and Characterization of Bacillus cereus SW7-1 in Bombyx mori (Lepidoptera: Bombycidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2015; 15:iev121. [PMID: 26411789 PMCID: PMC4626674 DOI: 10.1093/jisesa/iev121] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/06/2015] [Indexed: 06/05/2023]
Abstract
The bacterial diseases of silkworms cause significant reductions in sericulture and result in huge economic loss. This study aimed to identify and characterize a pathogen from diseased silkworm. SW7-1, a pathogenic bacterial strain, was isolated from the diseased silkworm. The strain was identified on the basis of its bacteriological properties and 16S rRNA gene sequence. The colony was round, slightly convex, opaque, dry, and milky on a nutrient agar medium, the colony also exhibited jagged edges. SW7-1 was Gram-positive, without parasporal crystal, and 0.8-1.2 by 2.6-3.4 µm in length, resembling long rods with rounded ends. The strain was positive to most of the physiological biochemical tests used in this study. The strain could utilize glucose, sucrose, and maltose. The results of its 16S rRNA gene sequence analysis revealed that SW7-1 shared the highest sequence identity (>99%) with Bacillus cereus strain 14. The bacterial strain was highly susceptible to gentamycin, streptomycin, erythromycin, norfloxacin, and ofloxacin and moderately susceptible to tetracycline and rifampicin. It exhibited resistance to other antibiotics. SW7-1 had hemolytic activity and could produce extracellular casease, lipase, and amylase. SW7-1 could reproduce septicemia-like symptoms with high mortality rate when re-fed to healthy silkworm. .The median lethal concentration (LC50) was 5.45 × 10(4) cfu/ml. Thus, SW7-1 was identified as B. cereus, which is a pathogen for silkworm and human infections are possible.
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Affiliation(s)
- Guan-Nan Li
- College of Biotechnology, Southwest University, Chongqing 400716, China State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China
| | - Xue-Juan Xia
- College of Food Science, Southwest University, Chongqing 400716, China
| | - Huan-Huan Zhao
- College of Biotechnology, Southwest University, Chongqing 400716, China State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China
| | - Parfait Sendegeya
- College of Biotechnology, Southwest University, Chongqing 400716, China State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China
| | - Yong Zhu
- College of Biotechnology, Southwest University, Chongqing 400716, China State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China
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Chromosome-Directed PCR-Based Detection and Quantification of Bacillus cereus Group Members with Focus on B. thuringiensis Serovar israelensis Active against Nematoceran Larvae. Appl Environ Microbiol 2015; 81:4894-903. [PMID: 25979887 DOI: 10.1128/aem.00671-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 05/06/2015] [Indexed: 11/20/2022] Open
Abstract
Bacillus thuringiensis serovar israelensis is a wide-spread soil bacterium affiliated with the B. cereus group (Bcg) and is widely used in biocontrol products applied against mosquito and black fly larvae. For monitoring and quantification of applied B. thuringiensis serovar israelensis and its effect on indigenous B. thuringiensis serovar israelensis and Bcg assemblages, efficient and reliable tools are essential. The abundance and properties of B. thuringiensis serovar israelensis strains in the environment traditionally have been investigated with cultivation-dependent techniques, which are hampered by low sensitivity and the morphological similarity between B. cereus and B. thuringiensis. Currently available PCR-based detection and quantification tools target markers located on plasmids. In this study, a new cultivation-independent PCR-based method for efficient and specific quantification of B. thuringiensis serovar israelensis and Bcg is presented, utilizing two sets of PCR primers targeting the bacterial chromosome. Sequence database searches and empirical tests performed on target and nontarget species, as well as on bulk soil DNA samples, demonstrated that this diagnostic tool is specific for B. thuringiensis serovar israelensis and Bcg. The method will be useful for comparisons of Bcg and B. thuringiensis serovar israelensis abundances in the same samples. Moreover, the effect of B. thuringiensis serovar israelensis-based insecticide application on the total Bcg assemblages, including indigenous populations, can be investigated. This type of information is valuable in risk assessment and policy making for use of B. thuringiensis serovar israelensis in the environment.
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