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Xiao D, Tong C, Yang T, Huo Z, Li Y, Zeng Z, Xiong W. First insights into antimicrobial resistance, toxigenic profiles, and genetic diversity in Bacillus cereus isolated from Chinese sausages. Lebensm Wiss Technol 2023. [DOI: 10.1016/j.lwt.2023.114717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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2
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Butcher M, Puiu D, Romagnoli M, Carroll KC, Salzberg SL, Nauen DW. Rapidly fatal infection with Bacillus cereus/thuringiensis: genome assembly of the responsible pathogen and consideration of possibly contributing toxins. Diagn Microbiol Infect Dis 2021; 101:115534. [PMID: 34601446 PMCID: PMC9716716 DOI: 10.1016/j.diagmicrobio.2021.115534] [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: 05/06/2021] [Revised: 08/27/2021] [Accepted: 08/28/2021] [Indexed: 10/20/2022]
Abstract
Bloodstream infection with Bacillus cereus/thuringiensis can be life threatening, particularly in patients who are severely immunocompromised. In this report we describe a case that progressed from asymptomatic to fatal over approximately 5 hours despite extensive resuscitation efforts. We identify the pathogen and assemble its genome, in which we find genes for toxins that may have contributed to the precipitous demise. In the context of this and other cases we discuss the possible indication for rapid appropriate antibiotic administration and potentially antitoxin treatment or toxin removal in fulminant illness in immunocompromised patients.
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Affiliation(s)
- Monica Butcher
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Daniela Puiu
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Mark Romagnoli
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Karen C Carroll
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Steven L Salzberg
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - David W Nauen
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA.
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Manktelow CJ, White H, Crickmore N, Raymond B. Divergence in environmental adaptation between terrestrial clades of the Bacillus cereus group. FEMS Microbiol Ecol 2020; 97:5974271. [PMID: 33175127 DOI: 10.1093/femsec/fiaa228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/06/2020] [Indexed: 12/25/2022] Open
Abstract
The Bacillus cereus group encompasses beneficial and harmful species in diverse niches and has a much debated taxonomy. Investigating whether selection has led to ecological divergence between phylogenetic clades can help understand the basis of speciation, and has implications for predicting biological safety across this group. Using three most terrestrial species in this group (B. cereus, Bacillus thuringiensis and Bacillus mycoides) we charactererized ecological specialization in terms of resource use, thermal adaptation and fitness in different environmental conditions and tested whether taxonomic species or phylogenetic clade best explained phenotypic variation. All isolates grew vigorously in protein rich media and insect cadavers, but exploitation of soil or plant derived nutrients was similarly weak for all. For B. thuringiensis and B. mycoides, clade and taxonomic species were important predictors of relative fitness in insect infections. Fully psychrotolerant isolates could outcompete B. thuringiensis in insects at low temperature, although psychrotolerance predicted growth in artificial media better than clade. In contrast to predictions, isolates in the Bacillus anthracis clade had sub-optimal growth at 37°C. The common ecological niche in these terrestrial B. cereus species is the ability to exploit protein rich resources such as cadavers. However, selection has led to different phylogenetic groups developing different strategies for accessing this resource. Thus, clades, as well as traditional taxonomic phenotypes, predict biologically important traits.
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Affiliation(s)
- C James Manktelow
- Centre for Ecology and Conservation, University of Exeter, Penryn campus, Penryn, TR10 9FE, UK
| | - Hugh White
- Centre for Ecology and Conservation, University of Exeter, Penryn campus, Penryn, TR10 9FE, UK
| | - Neil Crickmore
- School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Ben Raymond
- Centre for Ecology and Conservation, University of Exeter, Penryn campus, Penryn, TR10 9FE, UK
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Aoyagi T, Oshima K, Endo S, Baba H, Kanamori H, Yoshida M, Tokuda K, Kaku M. Ba813 harboring Bacillus cereus, genetically closely related to Bacillus anthracis, causing nosocomial bloodstream infection: Bacterial virulence factors and clinical outcome. PLoS One 2020; 15:e0235771. [PMID: 32658912 PMCID: PMC7357740 DOI: 10.1371/journal.pone.0235771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 06/23/2020] [Indexed: 12/18/2022] Open
Abstract
Bacillus cereus commonly causes catheter-related bloodstream infections (BSIs) in hospital settings, and occasionally occurs fatal central nervous system (CNS) complications. B. cereus harboring Ba813, a specific chromosomal marker of Bacillus anthracis, has been found in patients with severe infection and nosocomial BSI. However, the bacteriological profile and clinical feature of Ba813 (+) B. cereus are unclear. Fifty-three patients with B. cereus BSI were examined. Isolates were evaluated for Ba813, B. anthracis-related and food poisoning-related virulence, multilocus sequencing typing, and biofilm formation. Patients’ clinical records were reviewed retrospectively. The 53 isolates were comprised of 29 different sequence types in two distinct clades. Seventeen of the 53 (32%) B. cereus isolates including five sequence types possessed Ba813 and were classified into Clade-1/Cereus-III lineage which is most closely related to Anthracis lineage. No B. cereus possessed B. anthracis-related virulence genes. Ba813 (+) strains showed a lower prevalence of enterotoxin genes than Clade-2 strains (n = 4), but no difference from Clade-1. Ba813 (+) strains showed significantly lower biofilm formation than Clade-1/non-Cereus-III (n = 22) and Clade-2 strains, respectively. Compared to Clade-1/non-Cereus-III and Clade-2 B. cereus, Ba813 (+) strains were isolated more frequently from elderly patients, patients with indwelling central venous catheter rather than peripheral venous catheter, and patients who remained in the hospital for longer before BSI onset. No significant differences in disease severity or mortality were observed. Though two of the ten Ba813 (-) strains in Clade-1/Cereus III were isolated from the patients with CNS complication, no significant difference was observed in the bacterial profile and clinical characteristics among Clade-1/Cereus III strains. In conclusion, our report suggested that Ba813-harboring B. cereus strains, genetically closely related to B. anthracis, were abundant among B. cereus strains in the hospital setting, and might cause catheter-related nosocomial BSI. However, it did not affect the clinical outcomes.
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Affiliation(s)
- Tetsuji Aoyagi
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
- * E-mail:
| | - Kengo Oshima
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shiro Endo
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroaki Baba
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hajime Kanamori
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Makiko Yoshida
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Koichi Tokuda
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Mitsuo Kaku
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Infectious Diseases, Tohoku Medical and Pharmaceutical University, Sendai, Japan
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Akamatsu R, Suzuki M, Okinaka K, Sasahara T, Yamane K, Suzuki S, Fujikura D, Furuta Y, Ohnishi N, Esaki M, Shibayama K, Higashi H. Novel Sequence Type in Bacillus cereus Strains Associated with Nosocomial Infections and Bacteremia, Japan. Emerg Infect Dis 2019; 25:883-890. [PMID: 31002057 PMCID: PMC6478208 DOI: 10.3201/eid2505.171890] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
This sequence type was dominant in isolates from bacteremia patients in 3 hospitals. Bacillus cereus is associated with foodborne illnesses characterized by vomiting and diarrhea. Although some B. cereus strains that cause severe extraintestinal infections and nosocomial infections are recognized as serious public health threats in healthcare settings, the genetic backgrounds of B. cereus strains causing such infections remain unknown. By conducting pulsed-field gel electrophoresis and multilocus sequence typing, we found that a novel sequence type (ST), newly registered as ST1420, was the dominant ST isolated from the cases of nosocomial infections that occurred in 3 locations in Japan in 2006, 2013, and 2016. Phylogenetic analysis showed that ST1420 strains belonged to the Cereus III lineage, which is much closer to the Anthracis lineage than to other Cereus lineages. Our results suggest that ST1420 is a prevalent ST in B. cereus strains that have caused recent nosocomial infections in Japan.
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Méric G, Mageiros L, Pascoe B, Woodcock DJ, Mourkas E, Lamble S, Bowden R, Jolley KA, Raymond B, Sheppard SK. Lineage-specific plasmid acquisition and the evolution of specialized pathogens in Bacillus thuringiensis and the Bacillus cereus group. Mol Ecol 2018; 27:1524-1540. [PMID: 29509989 PMCID: PMC5947300 DOI: 10.1111/mec.14546] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 02/06/2018] [Accepted: 02/20/2018] [Indexed: 12/20/2022]
Abstract
Bacterial plasmids can vary from small selfish genetic elements to large autonomous replicons that constitute a significant proportion of total cellular DNA. By conferring novel function to the cell, plasmids may facilitate evolution but their mobility may be opposed by co-evolutionary relationships with chromosomes or encouraged via the infectious sharing of genes encoding public goods. Here, we explore these hypotheses through large-scale examination of the association between plasmids and chromosomal DNA in the phenotypically diverse Bacillus cereus group. This complex group is rich in plasmids, many of which encode essential virulence factors (Cry toxins) that are known public goods. We characterized population genomic structure, gene content and plasmid distribution to investigate the role of mobile elements in diversification. We analysed coding sequence within the core and accessory genome of 190 B. cereus group isolates, including 23 novel sequences and genes from 410 reference plasmid genomes. While cry genes were widely distributed, those with invertebrate toxicity were predominantly associated with one sequence cluster (clade 2) and phenotypically defined Bacillus thuringiensis. Cry toxin plasmids in clade 2 showed evidence of recent horizontal transfer and variable gene content, a pattern of plasmid segregation consistent with transfer during infectious cooperation. Nevertheless, comparison between clades suggests that co-evolutionary interactions may drive association between plasmids and chromosomes and limit wider transfer of key virulence traits. Proliferation of successful plasmid and chromosome combinations is a feature of specialized pathogens with characteristic niches (Bacillus anthracis, B. thuringiensis) and has occurred multiple times in the B. cereus group.
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Affiliation(s)
- Guillaume Méric
- The Milner Centre for EvolutionDepartment of Biology and BiochemistryUniversity of BathBathUK
| | | | - Ben Pascoe
- The Milner Centre for EvolutionDepartment of Biology and BiochemistryUniversity of BathBathUK
- MRC CLIMB ConsortiumUniversity of BathBathUK
| | - Dan J. Woodcock
- Mathematics Institute and Zeeman Institute for Systems Biology and Infectious Epidemiology ResearchUniversity of WarwickCoventryUK
| | - Evangelos Mourkas
- The Milner Centre for EvolutionDepartment of Biology and BiochemistryUniversity of BathBathUK
| | - Sarah Lamble
- Wellcome Trust Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Rory Bowden
- Wellcome Trust Centre for Human GeneticsUniversity of OxfordOxfordUK
| | | | - Ben Raymond
- Department of Life SciencesFaculty of Natural SciencesImperial College LondonAscotUK
- Department of BiosciencesUniversity of ExeterExeterUK
| | - Samuel K. Sheppard
- The Milner Centre for EvolutionDepartment of Biology and BiochemistryUniversity of BathBathUK
- MRC CLIMB ConsortiumUniversity of BathBathUK
- Department of ZoologyUniversity of OxfordOxfordUK
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7
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Raymond B, Federici BA. In defense of Bacillus thuringiensis, the safest and most successful microbial insecticide available to humanity - a response to EFSA. FEMS Microbiol Ecol 2017. [PMID: 28645183 PMCID: PMC5812528 DOI: 10.1093/femsec/fix084] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The Bacillus cereus group contains vertebrate pathogens such as B. anthracis and B. cereus and the invertebrate pathogen B. thuringiensis (Bt). Microbial biopesticides based on Bt are widely recognised as being among the safest and least environmentally damaging insecticidal products available. Nevertheless, a recent food-poisoning incident prompted a European Food Safety Authority review which argued that Bt poses a health risk equivalent to B. cereus, a causative agent of diarrhoea. However, a critical examination of available data, and this latest incident, provides no solid evidence that Bt causes diarrhoea. Although relatively high levels of B. cereus-like spores can occur in foods, genotyping demonstrates that these are predominantly naturally occurring strains rather than biopesticides. Moreover, MLST genotyping of >2000 isolates show that biopesticide genotypes have never been isolated from any clinical infection. MLST data demonstrate that B. cereus group is heterogeneous and formed of distinct clades with substantial differences in biology, ecology and host association. The group posing the greatest risk (the anthracis clade) is distantly related to the clade containing all biopesticides. These recent data support the long-held view that Bt and especially the strains used in Bt biopesticides are very safe for humans.
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Affiliation(s)
- Ben Raymond
- University of Exeter, Penryn campus, Penryn, TR10 9FE, UK
| | - Brian A Federici
- Department of Entomology and Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521 USA
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Yang Y, Yu X, Zhan L, Chen J, Zhang Y, Zhang J, Chen H, Zhang Z, Zhang Y, Lu Y, Mei L. Multilocus sequence type profiles of Bacillus cereus isolates from infant formula in China. Food Microbiol 2017; 62:46-50. [DOI: 10.1016/j.fm.2016.09.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 09/09/2016] [Accepted: 09/11/2016] [Indexed: 12/19/2022]
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9
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Yang Y, Gu H, Yu X, Zhan L, Chen J, Luo Y, Zhang Y, Zhang Y, Lu Y, Jiang J, Mei L. Genotypic heterogeneity of emetic toxin producing Bacillus cereus isolates from China. FEMS Microbiol Lett 2016; 364:fnw237. [PMID: 27744366 DOI: 10.1093/femsle/fnw237] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/24/2016] [Accepted: 10/14/2016] [Indexed: 11/14/2022] Open
Abstract
Emetic toxin-producing Bacillus cereus (emetic B. cereus) is the third member of B. cereus group whose toxins are encoded by megaplasmids, beside anthrax and insecticidal toxins of B. anthracis and B. thuringiensis, respectively. A total of 18 emetic isolates collected from food poisoning events, clinical and non-random food samples in Zhejiang province of China, were analyzed by plasmid screening, pulse field gel electrophoresis, multilocus sequence typing, and toxic gene identification to investigate their genotypic diversity. In this study, 13 plasmid profile types, 14 pulse types and 6 different STs from emetic isolates were detected, in which ST 1035,1038,1053,1054 and 1065 were first assigned and reported. The toxic gene ces existed on its own, or coexisted with other toxic genes bceT, cytk, entFM and nhe, but never with hbl in emetic isolates. The results demonstrated that the emetic B. cereus strains from China were heterologous at genotypic level.
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Affiliation(s)
- Yong Yang
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
| | - Hua Gu
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
| | - Xiaofeng Yu
- College of Food Science, Shihezi University, Shihezi 832001, Xinjiang Province, China
| | - Li Zhan
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
| | - Jiancai Chen
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
| | - Yun Luo
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
| | - Yunyi Zhang
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
| | - Yanjun Zhang
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
| | - Yiyu Lu
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
| | - Jianmin Jiang
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
| | - Lingling Mei
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
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11
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Zahner V, Silva ACTDCE, Moraes GPD, McIntosh D, Filippis ID. Extended genetic analysis of Brazilian isolates of Bacillus cereus and Bacillus thuringiensis. Mem Inst Oswaldo Cruz 2013; 108:65-72. [PMID: 23440117 PMCID: PMC3974328 DOI: 10.1590/s0074-02762013000100011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 07/17/2012] [Indexed: 11/22/2022] Open
Abstract
Multiple locus sequence typing (MLST) was undertaken to extend the genetic characterization of 29 isolates of Bacillus cereus and Bacillus thuringiensis previously characterized in terms of presence/absence of sequences encoding virulence factors and via variable number tandem repeat (VNTR). Additional analysis involved polymerase chain reaction for the presence of sequences (be, cytK, inA, pag, lef, cya and cap), encoding putative virulence factors, not investigated in the earlier study. MLST analysis ascribed novel and unique sequence types to each of the isolates. A phylogenetic tree was constructed from a single sequence of 2,838 bp of concatenated loci sequences. The strains were not monophyletic by analysis of any specific housekeeping gene or virulence characteristic. No clear association in relation to source of isolation or to genotypic profile based on the presence or absence of putative virulence genes could be identified. Comparison of VNTR profiling with MLST data suggested a correlation between these two methods of genetic analysis. In common with the majority of previous studies, MLST was unable to provide clarification of the basis for pathogenicity among members of the B. cereus complex. Nevertheless, our application of MLST served to reinforce the notion that B. cereus and B. thuringiensis should be considered as the same species.
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Affiliation(s)
- Viviane Zahner
- Laboratório de Transmissores de Leishmanioses, Setor de Entomologia Médica Forense, Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.
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12
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Turabelidze G, Gee JE, Hoffmaster AR, Manian F, Butler C, Byrd D, Schildknecht S, Hauser LC, Duncan M, Ferrett R, Evans D, Talley C. Contaminated ventilator air flow sensor linked to Bacillus cereus colonization of newborns. Emerg Infect Dis 2013; 19:781-3. [PMID: 23647973 PMCID: PMC3647488 DOI: 10.3201/eid1905.12039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We investigated Bacillus cereus–positive tracheal aspirates from infants on ventilators in a neonatal intensive care unit. Multilocus sequence typing determined a genetic match between strains isolated from samples from a case-patient and from the air flow sensor in the ventilator. Changing the sterilization method for sensors to steam autoclaving stopped transmission.
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Affiliation(s)
- George Turabelidze
- Missouri Department of Health and Senior Services, Jefferson City, Missouri 63103, USA.
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Turabelidze G, Gee JE, Hoffmaster AR, Manian F, Butler C, Byrd D, Schildknecht S, Hauser LC, Duncan M, Ferrett R, Evans D, Talley C. Contaminated Ventilator Air Flow Sensor Linked toBacillus cereusColonization of Newborns. Emerg Infect Dis 2013. [DOI: 10.3201/eid1905.120239] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Ehling-Schulz M, Messelhäusser U. Bacillus "next generation" diagnostics: moving from detection toward subtyping and risk-related strain profiling. Front Microbiol 2013; 4:32. [PMID: 23440299 PMCID: PMC3579190 DOI: 10.3389/fmicb.2013.00032] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 02/05/2013] [Indexed: 11/29/2022] Open
Abstract
The highly heterogeneous genus Bacillus comprises the largest species group of endospore forming bacteria. Because of their ubiquitous nature, Bacillus spores can enter food production at several stages resulting in significant economic losses and posing a potential risk to consumers due the capacity of certain Bacillus strains for toxin production. In the past, food microbiological diagnostics was focused on the determination of species using conventional culture-based methods, which are still widely used. However, due to the extreme intra-species diversity found in the genus Bacillus, DNA-based identification and typing methods are gaining increasing importance in routine diagnostics. Several studies showed that certain characteristics are rather strain-dependent than species-specific. Therefore, the challenge for current and future Bacillus diagnostics is not only the efficient and accurate identification on species level but also the development of rapid methods to identify strains with specific characteristics (such as stress resistance or spoilage potential), trace contamination sources, and last but not least discriminate potential hazardous strains from non-toxic strains.
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Affiliation(s)
- Monika Ehling-Schulz
- Institute of Functional Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna Vienna, Austria
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15
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Complete genome sequence of Bacillus cereus NC7401, which produces high levels of the emetic toxin cereulide. J Bacteriol 2012; 194:4767-8. [PMID: 22887669 DOI: 10.1128/jb.01015-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report the complete and annotated genome sequence of Bacillus cereus NC7401, a representative of the strain group that causes emetic-type food poisoning. The emetic toxin, cereulide, is produced by a nonribosomal protein synthesis (NRPS) system that is encoded by a gene cluster on a large resident plasmid, pNCcld.
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Fang Y, Li Z, Liu J, Shu C, Wang X, Zhang X, Yu X, Zhao D, Liu G, Hu S, Zhang J, Al-Mssallem I, Yu J. A pangenomic study of Bacillus thuringiensis. J Genet Genomics 2011; 38:567-76. [PMID: 22196399 DOI: 10.1016/j.jgg.2011.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Revised: 10/25/2011] [Accepted: 11/09/2011] [Indexed: 11/28/2022]
Abstract
Bacillus thuringiensis (B. thuringiensis) is a soil-dwelling Gram-positive bacterium and its plasmid-encoded toxins (Cry) are commonly used as biological alternatives to pesticides. In a pangenomic study, we sequenced seven B. thuringiensis isolates in both high coverage and base-quality using the next-generation sequencing platform. The B. thuringiensis pangenome was extrapolated to have 4196 core genes and an asymptotic value of 558 unique genes when a new genome is added. Compared to the pangenomes of its closely related species of the same genus, B. thuringiensis pangenome shows an open characteristic, similar to B. cereus but not to B. anthracis; the latter has a closed pangenome. We also found extensive divergence among the seven B. thuringiensis genome assemblies, which harbor ample repeats and single nucleotide polymorphisms (SNPs). The identities among orthologous genes are greater than 84.5% and the hotspots for the genome variations were discovered in genomic regions of 2.3-2.8Mb and 5.0-5.6Mb. We concluded that high-coverage sequence assemblies from multiple strains, before all the gaps are closed, are very useful for pangenomic studies.
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Affiliation(s)
- Yongjun Fang
- James D. Watson Institute of Genome Sciences, College of Life Science, Zhejiang University, Hangzhou 310058, China
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17
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Tourasse NJ, Helgason E, Klevan A, Sylvestre P, Moya M, Haustant M, Økstad OA, Fouet A, Mock M, Kolstø AB. Extended and global phylogenetic view of the Bacillus cereus group population by combination of MLST, AFLP, and MLEE genotyping data. Food Microbiol 2010; 28:236-44. [PMID: 21315979 DOI: 10.1016/j.fm.2010.06.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 06/26/2010] [Accepted: 06/30/2010] [Indexed: 11/18/2022]
Abstract
The Bacillus cereus group of bacteria includes species that can cause food-poisoning or spoilage, such as B. cereus, as well as Bacillus anthracis, the cause of anthrax. In the present report we have conducted a multi-datatype analysis using tools from the HyperCAT database (http://mlstoslo.uio.no/) that we recently developed, combining data from multilocus sequence typing (Tourasse et al., 2010), amplified fragment length polymorphism, and multilocus enzyme electrophoresis typing techniques. We provide a comprehensive snapshot of the B. cereus group population, incorporating 2213 isolates including 450 from food and dairy products, in the form of both phylogenetic supertrees and superclusters of genetically closely related isolates. Our main findings include the detection of phylogenetically separated groups of isolates possibly representing novel evolutionary lineages within the B. cereus group, a putative new branch of B. anthracis, as well as new groups of related strains containing both environmental and clinical isolates. In addition, the multi-datatype analysis revealed to a larger extent than previously recognized that food-borne isolates can share identical genotyping profiles with strains from various other origins. Altogether, the global analysis confirms and extends the results underlining the opportunistic nature of B. cereus group organisms, and the fact that isolates responsible for disease outbreaks and contamination of foodstuffs can originate from various genetic backgrounds.
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Affiliation(s)
- Nicolas J Tourasse
- Laboratory for Microbial Dynamics (LaMDa) and Department of Pharmaceutical Biosciences (Microbiology), University of Oslo, N-0316 Oslo, Norway.
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Kolstø AB, Tourasse NJ, Økstad OA. What sets Bacillus anthracis apart from other Bacillus species? Annu Rev Microbiol 2009; 63:451-76. [PMID: 19514852 DOI: 10.1146/annurev.micro.091208.073255] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bacillus anthracis is the cause of anthrax, and two large plasmids are essential for toxicity: pXO1, which contains the toxin genes, and pXO2, which encodes a capsule. B. anthracis forms a highly monomorphic lineage within the B. cereus group, but strains of Bacillus thuringiensis and B. cereus exist that are genetically closely related to the B. anthracis cluster. During the past five years B. cereus strains that contain the pXO1 virulence plasmid were discovered, and strains with both pXO1 and pXO2 have been isolated from great apes in Africa. Therefore, the presence of pXO1 and pXO2 no longer principally separates B. anthracis from other Bacilli. The B. anthracis lineage carries a specific mutation in the global regulator PlcR, which controls the transcription of secreted virulence factors in B. cereus and B. thuringiensis. Coevolution of the B. anthracis chromosome with its plasmids may be the basis for the successful development and uniqueness of the B. anthracis lineage.
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Affiliation(s)
- Anne-Brit Kolstø
- Laboratory for Microbial Dynamics and Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo 0316, Norway.
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Kozak NA, Benson RF, Brown E, Alexander NT, Taylor TH, Shelton BG, Fields BS. Distribution of lag-1 alleles and sequence-based types among Legionella pneumophila serogroup 1 clinical and environmental isolates in the United States. J Clin Microbiol 2009; 47:2525-35. [PMID: 19553574 PMCID: PMC2725700 DOI: 10.1128/jcm.02410-08] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 02/12/2009] [Accepted: 06/18/2009] [Indexed: 11/20/2022] Open
Abstract
Approximately 84% of legionellosis cases are due to Legionella pneumophila serogroup 1. Moreover, a majority of L. pneumophila serogroup 1 clinical isolates react positively with monoclonal antibody 2 (MAb2) of the international standard panel. Over 94% of the legionellosis outbreaks investigated by the Centers for Disease Control and Prevention are due to this subset of L. pneumophila serogroup 1. To date, there is no complete explanation for the enhanced ability of these strains to cause disease. To better characterize these organisms, we subtyped 100 clinical L. pneumophila serogroup 1 isolates and 50 environmental L. pneumophila serogroup 1 isolates from the United States by (i) reactivity with MAb2, (ii) presence of a lag-1 gene required for the MAb2 epitope, and (iii) sequence-based typing analysis. Our results showed that the MAb2 epitope and lag-1 gene are overrepresented in clinical L. pneumophila serogroup 1 isolates. MAb2 recognized 75% of clinical isolates but only 6% of environmental isolates. Similarly, 75% of clinical isolates but only 8% of environmental isolates harbored lag-1. We identified three distinct lag-1 alleles, referred to as Philadelphia, Arizona, and Lens alleles, among 79 isolates carrying this gene. The Arizona allele is described for the first time in this study. We identified 59 different sequence types (STs), and 34 STs (58%) were unique to the United States. Our results support the hypothesis that a select group of STs may have an enhanced ability to cause legionellosis. Combining sequence typing and lag-1 analysis shows that STs tend to associate with a single lag-1 allele type, suggesting a hierarchy of virulence genotypes. Further analysis of ST and lag-1 profiles may identify genotypes of L. pneumophila serogroup 1 that warrant immediate intervention.
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Affiliation(s)
- Natalia A Kozak
- Centers for Disease Control and Prevention, Atlanta, GA 30033, USA
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Didelot X, Barker M, Falush D, Priest FG. Evolution of pathogenicity in the Bacillus cereus group. Syst Appl Microbiol 2009; 32:81-90. [PMID: 19200684 DOI: 10.1016/j.syapm.2009.01.001] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Revised: 01/06/2009] [Accepted: 01/07/2009] [Indexed: 11/25/2022]
Abstract
The Bacillus cereus group of bacteria comprises soil-dwelling saprophytes but on occasion these bacteria can cause a wide range of diseases in humans, including food poisoning, systemic infections and highly lethal forms of anthrax. While anthrax is almost invariably caused by strains from a single evolutionary lineage, Bacillus anthracis, variation in the virulence properties of strains from other lineages has not been fully addressed. Using multi-locus sequence data from 667 strains, we reconstructed the evolutionary history of the B. cereus group in terms of both clonal inheritance and recombination. The strains included 155 clinical isolates representing B. anthracis, and isolates from emetic and diarrhoeal food poisoning, septicaemia and related infections, wound, and lung infections. We confirmed the existence of three major clades and found that clinical isolates of B. cereus (with the exception of emetic toxin-producing strains) are evenly distributed between and within clades 1 and 2. B. anthracis in particular and emetic toxin-producing B. cereus show more clonal structure and are restricted to clade 1. Our characterization of the patterns of genetic exchange showed that there exist partial barriers to gene flow between the three clades. The pathogenic strains do not exhibit atypically high or low rates of recombination, consistent with the opportunistic nature of most pathogenic infections. However, there have been a large number of recent imports in clade 1 of strains from external origins, which is indicative of an on-going shift in gene-flow boundaries for this clade.
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Affiliation(s)
- Xavier Didelot
- Department of Statistics, University of Warwick, Coventry CV4 7AL, UK.
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Hoffmaster AR, Novak RT, Marston CK, Gee JE, Helsel L, Pruckler JM, Wilkins PP. Genetic diversity of clinical isolates of Bacillus cereus using multilocus sequence typing. BMC Microbiol 2008; 8:191. [PMID: 18990211 PMCID: PMC2585095 DOI: 10.1186/1471-2180-8-191] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Accepted: 11/06/2008] [Indexed: 11/20/2022] Open
Abstract
Background Bacillus cereus is most commonly associated with foodborne illness (diarrheal and emetic) but is also an opportunistic pathogen that can cause severe and fatal infections. Several multilocus sequence typing (MLST) schemes have recently been developed to genotype B. cereus and analysis has suggested a clonal or weakly clonal population structure for B. cereus and its close relatives B. anthracis and B. thuringiensis. In this study we used MLST to determine if B. cereus isolates associated with illnesses of varying severity (e.g., severe, systemic vs. gastrointestinal (GI) illness) were clonal or formed clonal complexes. Results A retrospective analysis of 55 clinical B. cereus isolates submitted to the Centers for Disease Control and Prevention between 1954 and 2004 was conducted. Clinical isolates from severe infections (n = 27), gastrointestinal (GI) illness (n = 18), and associated isolates from food (n = 10) were selected for analysis using MLST. The 55 isolates were diverse and comprised 38 sequence types (ST) in two distinct clades. Of the 27 isolates associated with serious illness, 13 clustered in clade 1 while 14 were in clade 2. Isolates associated with GI illness were also found throughout clades 1 and 2, while no isolates in this study belonged to clade 3. All the isolates from this study belonging to the clade 1/cereus III lineage were associated with severe disease while isolates belonging to clade1/cereus II contained isolates primarily associated with severe disease and emetic illness. Only three STs were observed more than once for epidemiologically distinct isolates. Conclusion STs of clinical B. cereus isolates were phylogenetically diverse and distributed among two of three previously described clades. Greater numbers of strains will need to be analyzed to confirm if specific lineages or clonal complexes are more likely to contain clinical isolates or be associated with specific illness, similar to B. anthracis and emetic B. cereus isolates.
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Affiliation(s)
- Alex R Hoffmaster
- National Center for Zoonotic, Vector-borne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, USA.
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Jacobson MJ, Lin G, Whittam TS, Johnson EA. Phylogenetic analysis of Clostridium botulinum type A by multi-locus sequence typing. MICROBIOLOGY-SGM 2008; 154:2408-2415. [PMID: 18667573 DOI: 10.1099/mic.0.2008/016915-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The genus Clostridium comprises a heterogeneous group of organisms for which the phylogeny and evolutionary relationships are poorly understood. The elucidation of these evolutionary relationships necessitates the use of experimental methods that can distinguish Clostridium lineages that are time and cost effective, and can be accurately and reproducibly employed in different laboratories. Multi-locus sequence typing (MLST) has been successfully used as a reproducible and discriminating system in the study of eukaryotic and prokaryotic evolutionary biology, and for strain typing of various bacteria. In this study, MLST was applied to evaluate the evolutionary lineages in the serotype A group of Clostridium botulinum. C. botulinum type A has recently been shown to produce multiple subtypes, suggesting that it is not monophyletic as previously reported, but comprises distinct lineages. For MLST analysis, we initially evaluated 14 housekeeping genes (gapdh, tuf, sod, oppB, hsp60, dnaE, aroE, pta, 23S rDNA, aceK, rpoB, 16S rDNA, mdh and recA) for amplification and sequence analysis. In the first phase of the analysis, 30 C. botulinum type A strains producing botulinum neurotoxin subtypes A1-A4 were examined. Results of this pilot study suggested that seven of the genes (mdh, aceK, rpoB, aroE, hsp60, oppB and recA) could be used for elucidation of evolutionary lineages and strain typing. These seven housekeeping genes were successfully applied for the elucidation of lineages for 73 C. botulinum type A strains, which resulted in 24 distinct sequence types. This strategy should be applicable to phylogenetic studies and typing of other C. botulinum serotypes and Clostridium species.
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Affiliation(s)
- Mark J Jacobson
- Department of Bacteriology, Food Research Institute, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Guangyun Lin
- Department of Bacteriology, Food Research Institute, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Thomas S Whittam
- National Food Safety & Toxicology Center, Michigan State University, East Lansing, MI 48824-1314, USA
| | - Eric A Johnson
- Department of Bacteriology, Food Research Institute, University of Wisconsin-Madison, Madison, WI 53706, USA
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Dohmae S, Okubo T, Higuchi W, Takano T, Isobe H, Baranovich T, Kobayashi S, Uchiyama M, Tanabe Y, Itoh M, Yamamoto T. Bacillus cereus nosocomial infection from reused towels in Japan. J Hosp Infect 2008; 69:361-7. [PMID: 18602188 DOI: 10.1016/j.jhin.2008.04.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Accepted: 04/11/2008] [Indexed: 10/21/2022]
Abstract
It was noticed that there was an increase in Bacillus cereus nosocomial infections in the summer from 2000 to 2005. In 2005, five bloodstream infections occurred in five patients related to catheter use. The causative strains were distinct from each other and belonged to novel multilocus sequence types (ST): ST365, ST366, ST367 and ST368. Two ST365 strains from two patients were further distinguished by pulsed-field gel electrophoresis. B. cereus contamination was observed with reused (dried and steamed) towels (>10(6)cfu/towel) and washing machines in hospital linen rooms. B. cereus strains from towels belonged to ST167, ST365, ST380 and ST382, and a proportion of these were the same, or similar, to strains from patients. All the hospital strains of B. cereus were distinct from those from food-poisoning strains (ST26, ST142, ST381). Ciprofloxacin resistance was observed only in hospital strains. Neither emetic toxin nor cytotoxin K gene, usually present in food poisoning strains, were found in the hospital strains, except for one patient isolate. The data suggest that specific B. cereus strains are circulating within a hospital, with genotypes, antibiotic susceptibilities and virulence gene patterns generally distinct from those of food poisoning, and that in Japan, towels are an important source of contamination, especially in summer.
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Affiliation(s)
- S Dohmae
- Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Edwards MT, Fry NK, Harrison TG. Clonal population structure of Legionella pneumophila inferred from allelic profiling. Microbiology (Reading) 2008; 154:852-864. [DOI: 10.1099/mic.0.2007/012336-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Martin T. Edwards
- Statistics, Modelling and Bioinformatics Department, Health Protection Agency Centre for Infections, London, UK
- Respiratory and Systemic Infection Laboratory, Health Protection Agency Centre for Infections, London, UK
| | - Norman K. Fry
- Respiratory and Systemic Infection Laboratory, Health Protection Agency Centre for Infections, London, UK
| | - Timothy G. Harrison
- Respiratory and Systemic Infection Laboratory, Health Protection Agency Centre for Infections, London, UK
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Bavykin SG, Mikhailovich VM, Zakharyev VM, Lysov YP, Kelly JJ, Alferov OS, Gavin IM, Kukhtin AV, Jackman J, Stahl DA, Chandler D, Mirzabekov AD. Discrimination of Bacillus anthracis and closely related microorganisms by analysis of 16S and 23S rRNA with oligonucleotide microarray. Chem Biol Interact 2008; 171:212-35. [PMID: 17950718 PMCID: PMC3188417 DOI: 10.1016/j.cbi.2007.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 08/23/2007] [Accepted: 09/03/2007] [Indexed: 10/22/2022]
Abstract
Analysis of 16S rRNA sequences is a commonly used method for the identification and discrimination of microorganisms. However, the high similarity of 16S and 23S rRNA sequences of Bacillus cereus group organisms (up to 99-100%) and repeatedly failed attempts to develop molecular typing systems that would use DNA sequences to discriminate between species within this group have resulted in several suggestions to consider B. cereus and B. thuringiensis, or these two species together with B. anthracis, as one species. Recently, we divided the B. cereus group into seven subgroups, Anthracis, Cereus A and B, Thuringiensis A and B, and Mycoides A and B, based on 16S rRNA, 23S rRNA and gyrB gene sequences and identified subgroup-specific makers in each of these three genes. Here we for the first time demonstrated discrimination of these seven subgroups, including subgroup Anthracis, with a 3D gel element microarray of oligonucleotide probes targeting 16S and 23S rRNA markers. This is the first microarray enabled identification of B. anthracis and discrimination of these seven subgroups in pure cell cultures and in environmental samples using rRNA sequences. The microarray bearing perfect match/mismatch (p/mm) probe pairs was specific enough to discriminate single nucleotide polymorphisms (SNPs) and was able to identify targeted organisms in 5min. We also demonstrated the ability of the microarray to determine subgroup affiliations for B. cereus group isolates without rRNA sequencing. Correlation of these seven subgroups with groupings based on multilocus sequence typing (MLST), fluorescent amplified fragment length polymorphism analysis (AFLP) and multilocus enzyme electrophoresis (MME) analysis of a wide spectrum of different genes, and the demonstration of subgroup-specific differences in toxin profiles, psychrotolerance, and the ability to harbor some plasmids, suggest that these seven subgroups are not based solely on neutral genomic polymorphisms, but instead reflect differences in both the genotypes and phenotypes of the B. cereus group organisms.
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MESH Headings
- Bacillus anthracis/genetics
- Bacillus anthracis/isolation & purification
- Base Sequence
- Molecular Sequence Data
- Oligonucleotide Array Sequence Analysis
- Polymorphism, Single Nucleotide
- RNA, Ribosomal, 16S/analysis
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/analysis
- RNA, Ribosomal, 23S/genetics
- Sequence Homology, Nucleic Acid
- Species Specificity
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Affiliation(s)
- Sergei G Bavykin
- Center for Environmental and Security Science and Technology, Argonne National Laboratory, Argonne, IL 60439, USA.
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Tourasse NJ, Kolstø AB. SuperCAT: a supertree database for combined and integrative multilocus sequence typing analysis of the Bacillus cereus group of bacteria (including B. cereus, B. anthracis and B. thuringiensis). Nucleic Acids Res 2007; 36:D461-8. [PMID: 17982177 PMCID: PMC2238978 DOI: 10.1093/nar/gkm877] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The Bacillus cereus group of bacteria is an important group including mammalian and insect pathogens, such as B. anthracis, the anthrax bacterium, B. thuringiensis, used as a biological pesticide and B. cereus, often involved in food poisoning incidents. To characterize the population structure and epidemiology of these bacteria, five separate multilocus sequence typing (MLST) schemes have been developed, which makes results difficult to compare. Therefore, we have developed a database that compiles and integrates MLST data from all five schemes for the B. cereus group, accessible at http://mlstoslo.uio.no/. Supertree techniques were used to combine the phylogenetic information from analysis of all schemes and datasets, in order to produce an integrated view of the B. cereus group population. The database currently contains strain information and sequence data for 1029 isolates and 26 housekeeping gene fragments, which can be searched by keywords, MLST scheme, or sequence similarity. Supertrees can be browsed according to various criteria such as species, isolate source, or genetic distance, and subtrees containing strains of interest can be extracted. Besides analysis of the available data, the user has the possibility to enter her/his own sequences and compare them to the database and/or include them into the supertree reconstructions.
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Affiliation(s)
- Nicolas J Tourasse
- Department of Pharmaceutical Biosciences, University of Oslo, Oslo, Norway
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Olsen JS, Skogan G, Fykse EM, Rawlinson EL, Tomaso H, Granum PE, Blatny JM. Genetic distribution of 295 Bacillus cereus group members based on adk-screening in combination with MLST (Multilocus Sequence Typing) used for validating a primer targeting a chromosomal locus in B. anthracis. J Microbiol Methods 2007; 71:265-74. [PMID: 17997177 DOI: 10.1016/j.mimet.2007.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Revised: 09/21/2007] [Accepted: 10/01/2007] [Indexed: 10/22/2022]
Abstract
The genetic distribution of 295 Bacillus cereus group members has been investigated by using a modified Multilocus Sequence Typing method (MLST). By comparing the nucleic acid sequence of the adk gene fragment, isolates of B. cereus group members most related to B. anthracis may be easily identified. The genetic distribution, with focus on the B. anthracis close neighbours, was used to evaluate a new primer set for specific identification of B. anthracis. This primer set, BA5510-1/2, targeted the putative B. anthracis specific gene BA5510. Real-time PCR using BA5510-1/2 amplified the target fragment from all B. anthracis strains tested and only two (of 289) non-B. anthracis strains analysed. This is one of the most thoroughly validated chromosomal B. anthracis markers for real-time PCR identification, in which the screened collection contained several very closely related B. anthracis strains.
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Affiliation(s)
- Jaran S Olsen
- Forsvarets forskningsinstitutt FFI, Norwegian Defence Research Establishment, P. O. Box 25, N-2027 Kjeller, Norway.
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