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Johansson P, Säde E, Hultman J, Auvinen P, Björkroth J. Pangenome and genomic taxonomy analyses of Leuconostoc gelidum and Leuconostoc gasicomitatum. BMC Genomics 2022; 23:818. [PMID: 36494615 PMCID: PMC9733070 DOI: 10.1186/s12864-022-09032-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 11/21/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Leuconostoc gelidum and Leuconostoc gasicomitatum have dual roles in foods. They may spoil cold-stored packaged foods but can also be beneficial in kimchi fermentation. The impact in food science as well as the limited number of publicly available genomes prompted us to create pangenomes and perform genomic taxonomy analyses starting from de novo sequencing of the genomes of 37 L. gelidum/L. gasicomitatum strains from our culture collection. Our aim was also to evaluate the recently proposed change in taxonomy as well as to study the genomes of strains with different lifestyles in foods. METHODS We selected as diverse a set of strains as possible in terms of sources, previous genotyping results and geographical distribution, and included also 10 publicly available genomes in our analyses. We studied genomic taxonomy using pairwise average nucleotide identity (ANI) and calculation of digital DNA-DNA hybridisation (dDDH) scores. Phylogeny analyses were done using the core gene set of 1141 single-copy genes and a set of housekeeping genes commonly used for lactic acid bacteria. In addition, the pangenome and core genome sizes as well as some properties, such as acquired antimicrobial resistance (AMR), important due to the growth in foods, were analysed. RESULTS Genome relatedness indices and phylogenetic analyses supported the recently suggested classification that restores the taxonomic position of L. gelidum subsp. gasicomitatum back to the species level as L. gasicomitatum. Genome properties, such as size and coding potential, revealed limited intraspecies variation and showed no attribution to the source of isolation. The distribution of the unique genes between species and subspecies was not associated with the previously documented lifestyle in foods. None of the strains carried any acquired AMR genes or genes associated with any known form of virulence. CONCLUSION Genome-wide examination of strains confirms that the proposition to restore the taxonomic position of L. gasicomitatum is justified. It further confirms that the distribution and lifestyle of L. gelidum and L. gasicomitatum in foods have not been driven by the evolution of functional and phylogenetic diversification detectable at the genome level.
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Affiliation(s)
- Per Johansson
- grid.7737.40000 0004 0410 2071Department of Food Hygiene and Environmental Health, University of Helsinki, Helsinki, Finland
| | - Elina Säde
- grid.7737.40000 0004 0410 2071Department of Food Hygiene and Environmental Health, University of Helsinki, Helsinki, Finland
| | - Jenni Hultman
- grid.7737.40000 0004 0410 2071Department of Food Hygiene and Environmental Health, University of Helsinki, Helsinki, Finland
| | - Petri Auvinen
- grid.7737.40000 0004 0410 2071Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Johanna Björkroth
- grid.7737.40000 0004 0410 2071Department of Food Hygiene and Environmental Health, University of Helsinki, Helsinki, Finland
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Chen J, Lv H, Zhang Z, Zhang H, Zhang B, Wang X, Liu Y, Zhang M, Pang H, Qin G, Wang L, Tan Z. Multilocus Sequence Typing of Leuconostoc mesenteroides Strains From the Qinghai-Tibet Plateau. Front Microbiol 2021; 12:614286. [PMID: 33584616 PMCID: PMC7874059 DOI: 10.3389/fmicb.2021.614286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/05/2021] [Indexed: 12/21/2022] Open
Abstract
Leuconostoc mesenteroides strains were a type of epiphytic bacterium widely used in fermented foods and products in the biochemical and pharmaceutical industries but data on its presence in foods from Qinghai-Tibet Plateau in China was scarce. In this study, molecular analysis based on multilocus sequence typing (MLST) with eight housekeeping genes (pyrG, groeL, rpoB, recA, uvrC, murC, carB, and pheS) was carried out on 45 L. mesenteroides strains isolated from different plants and dairy products from Qinghai-Tibet Plateau in China. The objective of this study was to perform genetic diversity analysis and explore the relationship between strains and isolate samples or separate regions. A total of 25 sequence types (STs) were identified with a diversity of up to 55.6%, which were grouped into one clonal complexes (CCs), 3 doublets and 17 singletons by eBURST. The results of minimum spanning tree and clustering analysis indicated these L. mesenteroides strains from the Qinghai-Tibet Plateau were relatively weakly related to the isolated region. However, there was a close relationship between the genotypes of L. mesenteroides strains and the type of the isolated sample, which was consistent with the results of API 50CH. The MLST scheme presented in this study provides a shareable and comparable sequence database and enhances our knowledge of the population diversity of L. mesenteroides strains which will be further used for the selection of industrial strains.
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Affiliation(s)
- Jun Chen
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.,Henan Key Laboratory of Ion-Beam Bioengineering, School of Physics, Zhengzhou University, Zhengzhou, China
| | - Haoxin Lv
- School of Food Science and Technology, Henan University of Technology, Zhengzhou, China
| | - Zhixia Zhang
- Henan Key Laboratory of Ion-Beam Bioengineering, School of Physics, Zhengzhou University, Zhengzhou, China
| | - Hua Zhang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.,School of Food and Biological Engineering, Henan University of Animal Husbandry and Economy, Zhengzhou, China
| | - Bei Zhang
- Department of Chemical and Environmental Engineering, Jiaozuo University, Jiaozuo, China
| | - Xing Wang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Yuan Liu
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Miao Zhang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Huili Pang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Guangyong Qin
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Lei Wang
- Academy of Animal Science and Veterinary Medicine, Qinghai University, Xining, China
| | - Zhongfang Tan
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
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Jarvis KG, Daquigan N, White JR, Morin PM, Howard LM, Manetas JE, Ottesen A, Ramachandran P, Grim CJ. Microbiomes Associated With Foods From Plant and Animal Sources. Front Microbiol 2018; 9:2540. [PMID: 30405589 PMCID: PMC6206262 DOI: 10.3389/fmicb.2018.02540] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 10/04/2018] [Indexed: 12/28/2022] Open
Abstract
Food microbiome composition impacts food safety and quality. The resident microbiota of many food products is influenced throughout the farm to fork continuum by farming practices, environmental factors, and food manufacturing and processing procedures. Currently, most food microbiology studies rely on culture-dependent methods to identify bacteria. However, advances in high-throughput DNA sequencing technologies have enabled the use of targeted 16S rRNA gene sequencing to profile complex microbial communities including non-culturable members. In this study we used 16S rRNA gene sequencing to assess the microbiome profiles of plant and animal derived foods collected at two points in the manufacturing process; post-harvest/pre-retail (cilantro) and retail (cilantro, masala spice mixes, cucumbers, mung bean sprouts, and smoked salmon). Our findings revealed microbiome profiles, unique to each food, that were influenced by the moisture content (dry spices, fresh produce), packaging methods, such as modified atmospheric packaging (mung bean sprouts and smoked salmon), and manufacturing stage (cilantro prior to retail and at retail). The masala spice mixes and cucumbers were comprised mainly of Proteobacteria, Firmicutes, and Actinobacteria. Cilantro microbiome profiles consisted mainly of Proteobacteria, followed by Bacteroidetes, and low levels of Firmicutes and Actinobacteria. The two brands of mung bean sprouts and the three smoked salmon samples differed from one another in their microbiome composition, each predominated by either by Firmicutes or Proteobacteria. These data demonstrate diverse and highly variable resident microbial communities across food products, which is informative in the context of food safety, and spoilage where indigenous bacteria could hamper pathogen detection, and limit shelf life.
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Affiliation(s)
- Karen G. Jarvis
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD, United States
| | - Ninalynn Daquigan
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD, United States
| | | | - Paul M. Morin
- Office of Regulatory Affairs, Northeast Food and Feed Laboratory, U.S. Food and Drug Administration, Jamaica, NY, United States
| | - Laura M. Howard
- Office of Regulatory Affairs, Northeast Food and Feed Laboratory, U.S. Food and Drug Administration, Jamaica, NY, United States
| | - Julia E. Manetas
- Office of Regulatory Affairs, Northeast Food and Feed Laboratory, U.S. Food and Drug Administration, Jamaica, NY, United States
| | - Andrea Ottesen
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Padmini Ramachandran
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Christopher J. Grim
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD, United States
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4
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Poirier S, Rué O, Peguilhan R, Coeuret G, Zagorec M, Champomier-Vergès MC, Loux V, Chaillou S. Deciphering intra-species bacterial diversity of meat and seafood spoilage microbiota using gyrB amplicon sequencing: A comparative analysis with 16S rDNA V3-V4 amplicon sequencing. PLoS One 2018; 13:e0204629. [PMID: 30252901 PMCID: PMC6155546 DOI: 10.1371/journal.pone.0204629] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/11/2018] [Indexed: 12/21/2022] Open
Abstract
Meat and seafood spoilage ecosystems harbor extensive bacterial genomic diversity that is mainly found within a small number of species but within a large number of strains with different spoilage metabolic potential. To decipher the intraspecies diversity of such microbiota, traditional metagenetic analysis using the 16S rRNA gene is inadequate. We therefore assessed the potential benefit of an alternative genetic marker, gyrB, which encodes the subunit B of DNA gyrase, a type II DNA topoisomerase. A comparison between 16S rDNA-based (V3-V4) amplicon sequencing and gyrB-based amplicon sequencing was carried out in five types of meat and seafood products, with five mock communities serving as quality controls. Our results revealed that bacterial richness in these mock communities and food samples was estimated with higher accuracy using gyrB than using16S rDNA. However, for Firmicutes species, 35% of putative gyrB reads were actually identified as sequences of a gyrB paralog, parE, which encodes subunit B of topoisomerase IV; we therefore constructed a reference database of published sequences of both gyrB and pare for use in all subsequent analyses. Despite this co-amplification, the deviation between relative sequencing quantification and absolute qPCR quantification was comparable to that observed for 16S rDNA for all the tested species. This confirms that gyrB can be used successfully alongside 16S rDNA to determine the species composition (richness and evenness) of food microbiota. The major benefit of gyrB sequencing is its potential for improving taxonomic assignment and for further investigating OTU richness at the subspecies level, thus allowing more accurate discrimination of samples. Indeed, 80% of the reads of the 16S rDNA dataset were represented by thirteen 16S rDNA-based OTUs that could not be assigned at the species-level. Instead, these same clades corresponded to 44 gyrB-based OTUs, which differentiated various lineages down to the subspecies level. The increased ability of gyrB-based analyses to track and trace phylogenetically different groups of strains will generate improved resolution and more reliable results for studies of the strains implicated in food processes.
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Affiliation(s)
- Simon Poirier
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Olivier Rué
- MaIAGE, INRA, Université Paris-Saclay, Jouy-en-Josas, France
| | - Raphaëlle Peguilhan
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Gwendoline Coeuret
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | | | | | - Valentin Loux
- MaIAGE, INRA, Université Paris-Saclay, Jouy-en-Josas, France
| | - Stéphane Chaillou
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
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Mekadim C, Killer J, Pechar R, Mrázek J. Fragment of the aspartyl-tRNA synthetase applicable as a shared classification and phylogenetic marker in particular representatives of the order Lactobacillales. Folia Microbiol (Praha) 2018; 64:113-120. [PMID: 30094534 DOI: 10.1007/s12223-018-0638-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 08/06/2018] [Indexed: 12/23/2022]
Abstract
The order Lactobacillales represents a morphologically, metabolically, and physiologically diverse group of bacteria. Lactic acid bacteria represent the core of this phylogenetic group. They are a part of epiphytic microflora, fermented dairy, meat, fruit and vegetable products, and the digestive tract of humans and animals. Despite the fact that these bacteria form a phenotypically and genotypically heterogeneous group, their phylogenetic relationship enables to propose a common genetic marker usable in classification, typing, and phylogeny. By creation of consensus sequence based on available genomic sequences of some representatives of order Lactobacillales, a specific primer-pair binding variable region of aspS gene (length of 615 nts) encoding the aspartyl-tRNA synthetase was designed. This gene has not yet been used in classification and phylogeny of the order Lactobacillales, although it meets the requirements of molecular markers (distribution and single copy in bacterial genomes, functional constancy and genetic stability, sequence variability among taxonomic units, irreplaceable role in proteosynthesis). Primers were applied on 54 type and wild Lactobacillales strains. Obtained sequences allowed to provide alignments for purpose of phylogenetic tree reconstructions that uncovered particular phylogenetic clusters of vagococci/enterococci, obligately homofermentative and heterofermentative lactobacilli. Although a relatively short fragment of the aspS gene (approximately 33% of the complete gene sequence) was evaluated, much higher sequence variability (61.8% of pairwise identity) among strains examined compared with 16S rRNA gene (90.7%, length of 1318 nt) provides a relatively simple and effective tool for classification and typing of selected representatives of the order Lactobacillales.
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Affiliation(s)
- Chahrazed Mekadim
- Institute of Animal Physiology and Genetics, v.v.i., of the Czech Academy of Sciences, Vídeňská 1083, Prague 4 - Krč, 142 20, Czechia.,Faculty of Agrobiology, Food and Natural Resources, Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences, Kamýcká 129, Prague 6 - Suchdol, 165 00, Czechia
| | - Jiří Killer
- Institute of Animal Physiology and Genetics, v.v.i., of the Czech Academy of Sciences, Vídeňská 1083, Prague 4 - Krč, 142 20, Czechia. .,Faculty of Agrobiology, Food and Natural Resources, Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences, Kamýcká 129, Prague 6 - Suchdol, 165 00, Czechia.
| | - Radko Pechar
- Faculty of Agrobiology, Food and Natural Resources, Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences, Kamýcká 129, Prague 6 - Suchdol, 165 00, Czechia.,Food Research Institute Prague, Radiová 1285/7, Prague 10 - Hostivař, 102 00, Czechia
| | - Jakub Mrázek
- Institute of Animal Physiology and Genetics, v.v.i., of the Czech Academy of Sciences, Vídeňská 1083, Prague 4 - Krč, 142 20, Czechia
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6
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Bottari B, Felis GE, Salvetti E, Castioni A, Campedelli I, Torriani S, Bernini V, Gatti M. Effective identification of Lactobacillus casei group species: genome-based selection of the gene mutL as the target of a novel multiplex PCR assay. MICROBIOLOGY-SGM 2017; 163:950-960. [PMID: 28721852 DOI: 10.1099/mic.0.000497] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Lactobacillus casei,Lactobacillus paracasei and Lactobacillusrhamnosus form a closely related taxonomic group (the L. casei group) within the facultatively heterofermentative lactobacilli. Strains of these species have been used for a long time as probiotics in a wide range of products, and they represent the dominant species of nonstarter lactic acid bacteria in ripened cheeses, where they contribute to flavour development. The close genetic relationship among those species, as well as the similarity of biochemical properties of the strains, hinders the development of an adequate selective method to identify these bacteria. Despite this being a hot topic, as demonstrated by the large amount of literature about it, the results of different proposed identification methods are often ambiguous and unsatisfactory. The aim of this study was to develop a more robust species-specific identification assay for differentiating the species of the L. casei group. A taxonomy-driven comparative genomic analysis was carried out to select the potential target genes whose similarity could better reflect genome-wide diversity. The gene mutL appeared to be the most promising one and, therefore, a novel species-specific multiplex PCR assay was developed to rapidly and effectively distinguish L. casei, L. paracasei and L. rhamnosus strains. The analysis of a collection of 76 wild dairy isolates, previously identified as members of the L. casei group combining the results of multiple approaches, revealed that the novel designed primers, especially in combination with already existing ones, were able to improve the discrimination power at the species level and reveal previously undiscovered intraspecific biodiversity.
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Affiliation(s)
- Benedetta Bottari
- Department of Food and Drug Science, University of Parma, Viale delle Scienze 49/A, 43124 Parma, Italy.,Multidisciplinary Interdepartmental Dairy Center - MILC, University of Parma, Parma, Italy
| | - Giovanna E Felis
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Elisa Salvetti
- School of Microbiology and APC Microbiome Institute, University College Cork, Western Road, Cork, Ireland
| | - Anna Castioni
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.,Present address: Panificio Zorzi S.r.l., Loc. Brà 1, 37020 Brentino Belluno, Verona, Italy
| | - Ilenia Campedelli
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Sandra Torriani
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Valentina Bernini
- Department of Food and Drug Science, University of Parma, Viale delle Scienze 49/A, 43124 Parma, Italy
| | - Monica Gatti
- Department of Food and Drug Science, University of Parma, Viale delle Scienze 49/A, 43124 Parma, Italy.,Multidisciplinary Interdepartmental Dairy Center - MILC, University of Parma, Parma, Italy
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Kuda T, Nakano A, Takahashi H, Kimura B. Effect of the quantities of food residues on the desiccation resistance of spoilage lactic acid bacteria adhered to a stainless steel surface. Food Control 2016. [DOI: 10.1016/j.foodcont.2016.03.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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8
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Andreevskaya M, Hultman J, Johansson P, Laine P, Paulin L, Auvinen P, Björkroth J. Complete genome sequence of Leuconostoc gelidum subsp. gasicomitatum KG16-1, isolated from vacuum-packaged vegetable sausages. Stand Genomic Sci 2016; 11:40. [PMID: 27274361 PMCID: PMC4895993 DOI: 10.1186/s40793-016-0164-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 05/31/2016] [Indexed: 11/10/2022] Open
Abstract
Leuconostoc gelidum subsp. gasicomitatum is a predominant lactic acid bacterium (LAB) in spoilage microbial communities of different kinds of modified-atmosphere packaged (MAP) food products. So far, only one genome sequence of a poultry-originating type strain of this bacterium (LMG 18811(T)) has been available. In the current study, we present the completely sequenced and functionally annotated genome of strain KG16-1 isolated from a vegetable-based product. In addition, six other vegetable-associated strains were sequenced to study possible "niche" specificity suggested by recent multilocus sequence typing. The genome of strain KG16-1 consisted of one circular chromosome and three plasmids, which together contained 2,035 CDSs. The chromosome carried at least three prophage regions and one of the plasmids encoded a galactan degradation cluster, which might provide a survival advantage in plant-related environments. The genome comparison with LMG 18811(T) and six other vegetable strains suggests no major differences between the meat- and vegetable-associated strains that would explain their "niche" specificity. Finally, the comparison with the genomes of other leuconostocs highlights the distribution of functionally interesting genes across the L. gelidum strains and the genus Leuconostoc.
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Affiliation(s)
- Margarita Andreevskaya
- Institute of Biotechnology, University of Helsinki, Viikinkaari 5D, 00790 Helsinki, Finland
| | - Jenni Hultman
- Department of Food Hygiene and Environmental Health, University of Helsinki, Agnes Sjöbergin katu 2, 00790 Helsinki, Finland
| | - Per Johansson
- Department of Food Hygiene and Environmental Health, University of Helsinki, Agnes Sjöbergin katu 2, 00790 Helsinki, Finland
| | - Pia Laine
- Institute of Biotechnology, University of Helsinki, Viikinkaari 5D, 00790 Helsinki, Finland
| | - Lars Paulin
- Institute of Biotechnology, University of Helsinki, Viikinkaari 5D, 00790 Helsinki, Finland
| | - Petri Auvinen
- Institute of Biotechnology, University of Helsinki, Viikinkaari 5D, 00790 Helsinki, Finland
| | - Johanna Björkroth
- Department of Food Hygiene and Environmental Health, University of Helsinki, Agnes Sjöbergin katu 2, 00790 Helsinki, Finland
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Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium. PLoS One 2016; 11:e0156182. [PMID: 27219107 PMCID: PMC4878776 DOI: 10.1371/journal.pone.0156182] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 05/10/2016] [Indexed: 11/25/2022] Open
Abstract
Rathayibacter toxicus is a gram-positive bacterium that infects the floral parts of several Poaceae species in Australia. Bacterial ooze is often produced on the surface of infected plants and bacterial galls are produced in place of seed. R. toxicus is a regulated plant pathogen in the U.S. yet reliable detection and diagnostic tools are lacking. To better understand this geographically-isolated plant pathogen, genetic variation as a function of geographic location, host species, and date of isolation was determined for isolates collected over a forty-year period. Discriminant analyses of recently collected and archived isolates using Multi-Locus Sequence Typing (MLST) and Inter-Simple Sequence Repeats (ISSR) identified three populations of R. toxicus; RT-I and RT-II from South Australia and RT-III from Western Australia. Population RT-I, detected in 2013 and 2014 from the Yorke Peninsula in South Australia, is a newly emerged population of R. toxicus not previously reported. Commonly used housekeeping genes failed to discriminate among the R. toxicus isolates. However, strategically selected and genome-dispersed MLST genes representing an array of cellular functions from chromosome replication, antibiotic resistance and biosynthetic pathways to bacterial acquired immunity were discriminative. Genetic variation among isolates within the RT-I population was less than the within-population variation for the previously reported RT-II and RT-III populations. The lower relative genetic variation within the RT-I population and its absence from sampling over the past 40 years suggest its recent emergence. RT-I was the dominant population on the Yorke Peninsula during the 2013–2014 sampling period perhaps indicating a competitive advantage over the previously detected RT-II population. The potential for introduction of this bacterial plant pathogen into new geographic areas provide a rationale for understanding the ecological and evolutionary trajectories of R. toxicus.
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Vigentini I, Praz A, Domeneghetti D, Zenato S, Picozzi C, Barmaz A, Foschino R. Characterization of malolactic bacteria isolated from Aosta Valley wines and evidence of psychrotrophy in some strains. J Appl Microbiol 2016; 120:934-45. [PMID: 26820246 DOI: 10.1111/jam.13080] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 11/23/2015] [Accepted: 01/04/2016] [Indexed: 11/27/2022]
Affiliation(s)
- I. Vigentini
- Department of Food, Environmental and Nutrition Sciences; Università degli studi di Milano; Milan Italy
| | - A. Praz
- Department of Food, Environmental and Nutrition Sciences; Università degli studi di Milano; Milan Italy
| | | | - S. Zenato
- Institut Agricole Régional of Aosta; Aosta Italy
| | - C. Picozzi
- Department of Food, Environmental and Nutrition Sciences; Università degli studi di Milano; Milan Italy
| | - A. Barmaz
- Institut Agricole Régional of Aosta; Aosta Italy
| | - R. Foschino
- Department of Food, Environmental and Nutrition Sciences; Università degli studi di Milano; Milan Italy
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11
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Lactic acid bacteria and their controversial role in fresh meat spoilage. Meat Sci 2015; 109:66-74. [DOI: 10.1016/j.meatsci.2015.04.014] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 11/19/2022]
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