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Cytotoxicity and Antimicrobial Resistance of Aeromonas Strains Isolated from Fresh Produce and Irrigation Water. Antibiotics (Basel) 2023; 12:antibiotics12030511. [PMID: 36978377 PMCID: PMC10044025 DOI: 10.3390/antibiotics12030511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023] Open
Abstract
The genus Aeromonas has received constant attention in different areas, from aquaculture and veterinary medicine to food safety, where more and more frequent isolates are occurring with increased resistance to antibiotics. The present paper studied the interaction of Aeromonas strains isolated from fresh produce and water with different eukaryotic cell types with the aim of better understanding the cytotoxic capacity of these strains. To study host-cell pathogen interactions in Aeromonas, we used HT-29, Vero, J774A.1, and primary mouse embryonic fibroblasts. These interactions were analyzed by confocal microscopy to determine the cytotoxicity of the strains. We also used Galleria mellonella larvae to test their pathogenicity in this experimental model. Our results demonstrated that two strains showed high cytotoxicity in epithelial cells, fibroblasts, and macrophages. Furthermore, these strains showed high virulence using the G. mellonella model. All strains used in this paper generally showed low levels of resistance to the different families of the antibiotics being tested. These results indicated that some strains of Aeromonas present in vegetables and water pose a potential health hazard, displaying very high in vitro and in vivo virulence. This pathogenic potential, and some recent concerning findings on antimicrobial resistance in Aeromonas, encourage further efforts in examining the precise significance of Aeromonas strains isolated from foods for human consumption.
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Mursalim MF, Budiyansah H, Raharjo HM, Debnath PP, Sakulworakan R, Chokmangmeepisarn P, Yindee J, Piasomboon P, Elayaraja S, Rodkhum C. Diversity and antimicrobial susceptibility profiles of Aeromonas spp. isolated from diseased freshwater fishes in Thailand. JOURNAL OF FISH DISEASES 2022; 45:1149-1163. [PMID: 35598068 DOI: 10.1111/jfd.13650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/07/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Motile Aeromonas septicemia (MAS), a disease caused by Aeromonas spp., is recognized as a major disease in freshwater aquaculture. This study aimed to investigate the distribution and diversity of Aeromonas spp. and their antimicrobial susceptibility patterns. A total of 86 isolates of Aeromonas spp. were recovered from diseased freshwater fishes from 13 farms in Thailand. All isolates were identified using biochemical characteristics, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), polymerase chain reaction assays, and the gyrB gene sequence analysis. The result of MALDI-TOF MS showed 100% (86 isolates) accuracy at genus-level identification, and 88.4% (76 isolates) accuracy at species-level identification. Six species of Aeromonas were confirmed through nucleotide sequencing and phylogenetic analysis of the gyrB gene Aeromonas veronii (72.1%), Aeromonas jandaei (11.6%), Aeromonas schubertii (9.3%), Aeromonas diversa (3.5%), Aeromonas hydrophila (2.3%), and Aeromonas punctata (1.2%). Antimicrobial susceptibility tests for all isolates revealed resistance against amoxicillin (99%), ampicillin (98%), oxolinic acid (81.4%), oxytetracycline (77%), trimethoprim-sulfamethoxazole (24%), and enrofloxacin (21%). The multiple antibiotic resistance (MAR) index varied between 0.14 and 0.86, with MAR values more than 0.2 in 99% of isolates. Furthermore, four diverse multidrug-resistant (MDR) patterns were found among Aeromonas isolates. Our finding show that A. veronii is the most abundant species in Thai cultured freshwater fish with the highest MDR patterns.
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Affiliation(s)
- Muhammad Fadhlullah Mursalim
- Center of Excellence in Fish Infectious Diseases Research Unit (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- The International Graduate Course of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Veterinary Study Program, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Hendri Budiyansah
- Center of Excellence in Fish Infectious Diseases Research Unit (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- The International Graduate Course of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Hartanto Mulyo Raharjo
- Center of Excellence in Fish Infectious Diseases Research Unit (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- The International Graduate Course of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Partho Pratim Debnath
- Center of Excellence in Fish Infectious Diseases Research Unit (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Rungnapa Sakulworakan
- Center of Excellence in Fish Infectious Diseases Research Unit (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- The International Graduate Course of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Putita Chokmangmeepisarn
- Center of Excellence in Fish Infectious Diseases Research Unit (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- The International Graduate Course of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Jitrapa Yindee
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Patharapol Piasomboon
- Department of Veterinary Medicine, Faculty of Veterinary Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Sivaramasamy Elayaraja
- Center of Excellence in Fish Infectious Diseases Research Unit (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Channarong Rodkhum
- Center of Excellence in Fish Infectious Diseases Research Unit (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
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3
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Gosselin S, Fullmer MS, Feng Y, Gogarten JP. Improving Phylogenies Based on Average Nucleotide Identity, Incorporating Saturation Correction and Nonparametric Bootstrap Support. Syst Biol 2022; 71:396-409. [PMID: 34289044 PMCID: PMC8830074 DOI: 10.1093/sysbio/syab060] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 07/12/2021] [Accepted: 07/17/2021] [Indexed: 11/13/2022] Open
Abstract
Whole-genome comparisons based on average nucleotide identities (ANI) and the genome-to-genome distance calculator have risen to prominence in rapidly classifying prokaryotic taxa using whole-genome sequences. Some implementations have even been proposed as a new standard in species classification and have become a common technique for papers describing newly sequenced genomes. However, attempts to apply whole-genome divergence data to the delineation of higher taxonomic units and to phylogenetic inference have had difficulty matching those produced by more complex phylogenetic methods. We present a novel method for generating statistically supported phylogenies of archaeal and bacterial groups using a combined ANI and alignment fraction-based metric. For the test cases to which we applied the developed approach, we obtained results comparable with other methodologies up to at least the family level. The developed method uses nonparametric bootstrapping to gauge support for inferred groups. This method offers the opportunity to make use of whole-genome comparison data, that is already being generated, to quickly produce phylogenies including support for inferred groups. Additionally, the developed ANI methodology can assist the classification of higher taxonomic groups.[Average nucleotide identity (ANI); genome evolution; prokaryotic species delineation; taxonomy.].
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Affiliation(s)
- Sean Gosselin
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268-3125, USA
| | - Matthew S Fullmer
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268-3125, USA.,Bioinformatics Institute, School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
| | - Yutian Feng
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268-3125, USA
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268-3125, USA.,Institute for Systems Genomics, University of Connecticut, Storrs, CT 06268-3125, USA
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4
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Song HC, Yang BT, Zhao T, Sun YF, Zhou JH, Shan XF, Qian AD, Sun WC, Kang YH. Comparative genomics analysis of strains from diverse sources reveals the evolutionary relationship of Aeromonas veronii. Microb Pathog 2021; 159:105134. [PMID: 34400283 DOI: 10.1016/j.micpath.2021.105134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/27/2021] [Accepted: 08/07/2021] [Indexed: 10/20/2022]
Abstract
Aeromonas veronii (A. veronii, AV) strains are emerging zoonotic and aquatic pathogens, yet we know very little about their genomics. This study aims to utilize comparative genomics to investigate the intraspecific genetic diversity, differences in virulence factors and evolutionary mechanisms of A. veronii strains from diverse sources and to fundamentally demonstrate their pathogenic mechanisms. We conducted comparative genomics analysis of 39 A. veronii strains from different sources and found that 1993 core genes are shared by these strains and that these shared core genes may be necessary to maintain the basic characteristics of A. veronii. Additionally, phylogenetic relationship analysis based on these shared genes revealed that a distant relationship between the AMC34 strain and the other 38 strains but that, the genetic relationship among the 38 strains is relatively close, indicating that AMC34 may not belong to A. veronii. Furthermore, analysis of shared core genes and average nucleotide identity (ANI) values showed no obvious correlation with the location of A. veronii isolation and genetic relationship. Our research indicates the evolutionary mechanism of A. veronii from different sources and provides new insights for a deeper understanding of its pathogenic mechanism.
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Affiliation(s)
- Hai-Chao Song
- College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, Jilin, 130118, China
| | - Bin-Tong Yang
- College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, Jilin, 130118, China
| | - Tong Zhao
- College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, Jilin, 130118, China
| | - Yu-Feng Sun
- College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, Jilin, 130118, China
| | - Jin-Hua Zhou
- College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, Jilin, 130118, China
| | - Xiao-Feng Shan
- College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, Jilin, 130118, China
| | - Ai-Dong Qian
- College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, Jilin, 130118, China
| | - Wen-Chao Sun
- Institute of Virology, Wenzhou University, Wenzhou, Zhejiang, 325035, China.
| | - Yuan-Huan Kang
- College of Veterinary Medicine, College of Animal Science and Technology, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, Jilin, 130118, China.
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Kloub L, Gosselin S, Fullmer M, Graf J, Gogarten JP, Bansal MS. Systematic Detection of Large-Scale Multigene Horizontal Transfer in Prokaryotes. Mol Biol Evol 2021; 38:2639-2659. [PMID: 33565580 PMCID: PMC8136488 DOI: 10.1093/molbev/msab043] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Horizontal gene transfer (HGT) is central to prokaryotic evolution. However, little is known about the “scale” of individual HGT events. In this work, we introduce the first computational framework to help answer the following fundamental question: How often does more than one gene get horizontally transferred in a single HGT event? Our method, called HoMer, uses phylogenetic reconciliation to infer single-gene HGT events across a given set of species/strains, employs several techniques to account for inference error and uncertainty, combines that information with gene order information from extant genomes, and uses statistical analysis to identify candidate horizontal multigene transfers (HMGTs) in both extant and ancestral species/strains. HoMer is highly scalable and can be easily used to infer HMGTs across hundreds of genomes. We apply HoMer to a genome-scale data set of over 22,000 gene families from 103 Aeromonas genomes and identify a large number of plausible HMGTs of various scales at both small and large phylogenetic distances. Analysis of these HMGTs reveals interesting relationships between gene function, phylogenetic distance, and frequency of multigene transfer. Among other insights, we find that 1) the observed relative frequency of HMGT increases as divergence between genomes increases, 2) HMGTs often have conserved gene functions, and 3) rare genes are frequently acquired through HMGT. We also analyze in detail HMGTs involving the zonula occludens toxin and type III secretion systems. By enabling the systematic inference of HMGTs on a large scale, HoMer will facilitate a more accurate and more complete understanding of HGT and microbial evolution.
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Affiliation(s)
- Lina Kloub
- Department of Computer Science and Engineering, University of Connecticut, Storrs, CT, USA
| | - Sean Gosselin
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Matthew Fullmer
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA.,Bioinformatics Institute, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Joerg Graf
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA.,The Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA.,The Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
| | - Mukul S Bansal
- Department of Computer Science and Engineering, University of Connecticut, Storrs, CT, USA.,The Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
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Probiotic Bacteria with High Alpha-Gal Content Protect Zebrafish against Mycobacteriosis. Pharmaceuticals (Basel) 2021; 14:ph14070635. [PMID: 34208966 PMCID: PMC8308674 DOI: 10.3390/ph14070635] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/28/2021] [Accepted: 06/28/2021] [Indexed: 12/22/2022] Open
Abstract
Mycobacteriosis affects wild fish and aquaculture worldwide, and alternatives to antibiotics are needed for an effective and environmentally sound control of infectious diseases. Probiotics have shown beneficial effects on fish growth, nutrient metabolism, immune responses, disease prevention and control, and gut microbiota with higher water quality. However, the identification and characterization of the molecules and mechanisms associated with probiotics is a challenge that requires investigation. To address this challenge, herein we used the zebrafish model for the study of the efficacy and mechanisms of probiotic interventions against tuberculosis. First, bacteria from fish gut microbiota were identified with high content of the surface glycotope Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) that has been shown to induce protective immune responses. The results showed that probiotics of selected bacteria with high α-Gal content, namely Aeromonas veronii and Pseudomonas entomophila, were biosafe and effective for the control of Mycobacterium marinum. Protective mechanisms regulating immunity and metabolism activated in response to α-Gal and probiotics with high α-Gal content included modification of gut microbiota composition, B-cell maturation, anti-α-Gal antibodies-mediated control of mycobacteria, induced innate immune responses, beneficial effects on nutrient metabolism and reduced oxidative stress. These results support the potential of probiotics with high -Gal content for the control of fish mycobacteriosis and suggested the possibility of exploring the development of combined probiotic treatments alone and in combination with -Gal for the control of infectious diseases.
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Macrobdella decora: Old World Leech Gut Microbial Community Structure Conserved in a New World Leech. Appl Environ Microbiol 2021; 87:AEM.02082-20. [PMID: 33674439 DOI: 10.1128/aem.02082-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 02/18/2021] [Indexed: 01/04/2023] Open
Abstract
Leeches are found in terrestrial, aquatic, and marine habitats on all continents. Sanguivorous leeches have been used in medicine for millennia. Modern scientific uses include studies of neurons, anticoagulants, and gut microbial symbioses. Hirudo verbana, the European medicinal leech, maintains a gut community dominated by two bacterial symbionts, Aeromonas veronii and Mucinivorans hirudinis, which sometimes account for as much as 97% of the total crop microbiota. The highly simplified gut anatomy and microbiome of H. verbana make it an excellent model organism for studying gut microbial dynamics. The North American medicinal leech, Macrobdella decora, is a hirudinid leech native to Canada and the northern United States. In this study, we show that M. decora symbiont communities are very similar to those in H. verbana. We performed an extensive study using field-caught M. decora and purchased H. verbana from two suppliers. Deep sequencing of the V4 region of the 16S rRNA gene allowed us to determine that the core microbiome of M. decora consists of Bacteroides, Aeromonas, Proteocatella, and Butyricicoccus. The analysis revealed that the compositions of the gut microbiomes of the two leech species were significantly different at all taxonomic levels. The R 2 value was highest at the genus and amplicon sequence variant (ASV) levels and much lower at the phylum, class, and order levels. The gut and bladder microbial communities were distinct. We propose that M. decora is an alternative to H. verbana for studies of wild-caught animals and provide evidence for the conservation of digestive-tract and bladder symbionts in annelid models.IMPORTANCE Building evidence implicates the gut microbiome in critical animal functions such as regulating digestion, nutrition, immune regulation, and development. Simplified, phylogenetically diverse models for hypothesis testing are necessary because of the difficulty of assigning causative relationships in complex gut microbiomes. Previous research used Hirudo verbana as a tractable animal model of digestive-tract symbioses. Our data show that Macrobdella decora may work just as well without the drawback of being an endangered organism and with the added advantage of easy access to field-caught specimens. The similarity of the microbial community structures of species from two different continents reveals the highly conserved nature of the microbial symbionts in sanguivorous leeches.
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Thomas SG, Abajorga M, Glover MA, Wengert PC, Parthasarathy A, Savka MA, Wadsworth CB, Shipman PA, Hudson AO. Aeromonas hydrophila RIT668 and Citrobacter portucalensis RIT669-Potential Zoonotic Pathogens Isolated from Spotted Turtles. Microorganisms 2020; 8:microorganisms8111805. [PMID: 33212916 PMCID: PMC7698337 DOI: 10.3390/microorganisms8111805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/06/2020] [Accepted: 11/13/2020] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial resistance (AMR) is one of the biggest challenges of the 21st century, and biofilm formation enables bacteria to resist antibiotic at much higher concentrations than planktonic cells. Earlier, we showed that the Gram-negative Aeromonas hydrophila RIT668 and Citrobacter portucalensis RIT669 (closely related to C. freundii NBRC 12681) from infected spotted turtles (Clemmys guttata), formed biofilms and upregulated toxin expression on plastic surfaces, and were predicted to possess multiple antibiotic resistance genes. Here, we show that they each resist several antibiotics in the planktonic phase, but were susceptible to neomycin, and high concentrations of tetracycline and cotrimoxazole. The susceptibility of their biofilms to neomycin and cotrimoxazole was tested using the Calgary device. For A. hydrophila, the minimum inhibitory concentration (MIC) = 500-1000, and the minimum biofilm eradication concentration (MBEC) > 1000 μg/mL, using cotrimoxazole, and MIC = 32.3-62.5, and MBEC > 1000 μg/mL, using neomycin. For C. freundii MIC = 7.8-15.6, and, MBEC > 1000 μg/mL, using cotrimoxazole, and MIC = 7.8, and MBEC > 1000 μg/mL, using neomycin. Both A. hydrophila and C. portucalensis activated an acyl homoserine lactone (AHL) dependent biosensor, suggesting that quorum sensing could mediate biofilm formation. Their multidrug resistance in the planktonic form, and weak biofilm eradication even with neomycin and cotrimoxazole, indicate that A. hydrophila and C. portucalensis are potential zoonotic pathogens, with risks for patients living with implants.
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Šubrtová Salmonová H, Marchi M, Doskočil I, Kodešová T, Vlková E. Pathogenic profile and cytotoxic activity of Aeromonas spp. isolated from Pectinatella magnifica and surrounding water in the South Bohemian aquaculture region. JOURNAL OF FISH DISEASES 2020; 43:1213-1227. [PMID: 32776333 DOI: 10.1111/jfd.13223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/25/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
Pectinatella magnifica is an invasive freshwater bryozoan that has expanded in many localities worldwide, including fishing areas. It contains microbial communities, predominantly consisting of Aeromonas bacteria that are frequently associated with fish infections. The objective of this study was to investigate the potential pathogenicity of Aeromonas spp. associated with P. magnifica and evaluate the health risks for fish. Aeromonas strains were isolated from P. magnifica (101 strains) and from surrounding water (29 strains) in the South Bohemian region and investigated for the presence of 14 virulence-associated genes using PCR. We demonstrated high prevalence of phospholipase GCAT, polar flagellin, enolase, DNAse, aerolysin/cytotoxic enterotoxin, serine protease and heat-stable cytotonic enterotoxin-coding genes. Further, all twelve isolates that were analysed for cytotoxicity against intestinal epithelial cells were found to be cytotoxic. Six of the isolates were also tested as co-cultures composed of pairs. Enhanced cytotoxicity was observed when the pair was composed of strains from different species. In conclusion, P. magnifica is colonized by Aeromonas strains that have a relatively high prevalence of virulence-associated genes and the ability to provoke disease. Results also suggest a possibly increased risk arising from mixed infections.
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Affiliation(s)
- Hana Šubrtová Salmonová
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Matilde Marchi
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Ivo Doskočil
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Tereza Kodešová
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Eva Vlková
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Prague, Czech Republic
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10
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Huang M, Chen H, Li C, Liu Y, Gan C, El-Sayed Ahmed MAEG, Liu R, Shen C, Zhong R, Tian GB, Huang X, Xia J. Rapid Fulminant Progression and Mortality Secondary to Aeromonas dhakensis Septicemia with Hepatitis B Virus Infection Following the Ingestion of Snakehead Fish in Mainland China: A Case Report. Foodborne Pathog Dis 2020; 17:743-749. [PMID: 32985901 DOI: 10.1089/fpd.2019.2780] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Aeromonas dhakensis is an important ubiquitous Gram-negative and freshwater bacterium detected in different reservoirs. It can cause invasive diseases in humans. Herein, we report the first case in Mainland China of a fulminant death of a 29-year-old man as a result of a new, unexpected association between septicemic A. dhakensis and hepatitis B viral infection (HBV). Herein, the patient died from multiple organ failure 5 d postadmission after the ingestion of Snakehead Fish meal. The isolated bacterium was initially misidentified as Aeromonas hydrophila using VITEK-2, while whole-genome sequencing (WGS) revealed that the isolate is A. dhakensis. WGS revealed the occurrence of three antimicrobial genes of resistance: imiH, cphA2, and blaOXA-12; besides, major virulence factors were detected. In silico, multilocus sequence typing (MLST) showed that our A. dhakensis 17FW001 belonged to a novel sequence type (ST557). A comparative genomic analysis of our isolate with nine selected Aeromonas species was done, which elucidated the pathogenicity of our A. dhakensis. In conclusion, we reported for the first time the association between A. dhakensis and HBV in Mainland China. We revealed that septicemic A. dhakensis could result in severe adverse clinical outcomes that end up with unexpected fulminant death especially when it is accompanied with HBV and sheds light on the virulence of A. dhakensis and the high rate of its misdiagnosis that requires to urgently consider screening of all cases of A. dhakensis for HBV in the future. Besides, caution should be taken while dealing with snakeheads which act as a vector for A. dhakensis.
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Affiliation(s)
- Mingxing Huang
- Department of Infectious Diseases, Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, China
| | - Hongtao Chen
- Clinical Laboratory, Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, China
| | - Chunna Li
- Department of Infectious Diseases, Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, China
| | - Yan Liu
- Clinical Laboratory, Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, China
| | - Chongjie Gan
- Department of Infectious Diseases, Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, China
| | - Mohamed Abd El-Gawad El-Sayed Ahmed
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China.,Department of Microbiology and Immunology, Faculty of Pharmaceutical Sciences and Drug Manufacturing, Misr University for Science and Technology (MUST), Cairo, 6th of October City, Egypt
| | - Ruihong Liu
- United Laboratory of the Fifth Affiliated Hospital and BGI, Department of Experimental Medicine, Guangdong Provincial Engineering Research Center of Molecular Imaging, Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, China
| | - Cong Shen
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Ruoxuan Zhong
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Guo-Bao Tian
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Xi Huang
- Program of Pathobiology and Immunology, Fifth Affiliated Hospital of Sun Yat-sen University, Sun Yat-sen University, Zhuhai, China
| | - Jinyu Xia
- Department of Infectious Diseases, Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, China
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Huang H, Zhou P, Chen P, Xia L, Hu S, Yi G, Lu J, Yang S, Xie J, Peng J, Ding X. Alteration of the gut microbiome and immune factors of grass carp infected with Aeromonas veronii and screening of an antagonistic bacterial strain (Streptomyces flavotricini). Microb Pathog 2020; 143:104092. [PMID: 32145322 DOI: 10.1016/j.micpath.2020.104092] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/19/2020] [Accepted: 02/19/2020] [Indexed: 12/11/2022]
Abstract
Aeromonas veronii is a widely distributed novel pathogen that can affect humans and animals, it can cause sepsis in fish with high mortality and serious economic losses to aquaculture. In the study, the gut microbiome of the infected and uninfected grass carp with Aeromonas veronii were analyzed probiotics and pathogenic bacteria by the Miseq high-throughput sequencing, the results showed that the infected fish were significantly higher in Proteobacteria, Firmicutes, Fusobacteria, and the immune factors in liver and kidney were up-regulated by qRT-PCR. In order to effectively inhibit the pathogen, we screened an actinomycete strain and had good antibacterial effect on Aeromonas veronii. The new antagonistic bacteria was named as Streptomyces flavotricini X101, the whole genome sequencing revealed that the metabolic process was most active. After grass carp was inoculated with the minimum inhibitory concentration of 900 μg/mL of the strain's fermentation supernatant, then Aeromonas veronii was injected, we found that the pathological symptoms such as body surface, anus and abdominal congestion were alleviated by H&E staining. Cellular experiments showed that it wasn't toxic to liver cells of grass carp. Overall, this is the first study of changes in intestinal flora, phenotype, and immune factors in grass crap infected with Aeromonas veronii, it had important theoretical significance and application value for immunization and prevention.
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Affiliation(s)
- Haiyan Huang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Pengji Zhou
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Pei Chen
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Liqiu Xia
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Shengbiao Hu
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Ganfeng Yi
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Jiaoyang Lu
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Shuqing Yang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Junyan Xie
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Jinli Peng
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
| | - Xuezhi Ding
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, 410081, China.
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12
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Smyrli M, Triga A, Dourala N, Varvarigos P, Pavlidis M, Quoc VH, Katharios P. Comparative Study on A Novel Pathogen of European Seabass. Diversity of Aeromonas veronii in the Aegean Sea. Microorganisms 2019; 7:microorganisms7110504. [PMID: 31671797 PMCID: PMC6921072 DOI: 10.3390/microorganisms7110504] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/16/2019] [Accepted: 10/25/2019] [Indexed: 01/01/2023] Open
Abstract
Aeromonas veronii is an emerging pathogen causing severe pathology and mortalities in European seabass aquaculture in the Aegean Sea, Mediterranean. More than 50 strains of the pathogen were characterized biochemically and genetically in order to study the epidemiology of the disease, as well as the phylogeny and virulence of the bacterium. Based on the phenotypic characteristics, the isolates form three groups consisting of: (a) the West Aegean Sea, non-motile, non-pigment-producing strains, (b) the West Aegean Sea, motile, and pigment-producing strains and (c) the East Aegean Sea motile strains that produce minute amounts of pigment. All strains were highly similar at the genomic level; however, the pattern of West/East geographic origin was reflected in biochemical properties, in general genomic level comparison and in the putative virulent factors studied. Type VI secretion system was not detected in the western strains. The outer membrane protein (OMP) profile which contains proteins that are putative antigenic factors, was very similar between strains from the different areas. Although most of the OMPs were detected in all strains with great sequence similarity, diversification according to geographic origin was evident in known antigenic factors such as the maltoporin LamB. A systematic comparative analysis of the strains is presented and discussed in view of the emergence of A. veronii as a significant pathogen for the Mediterranean aquaculture.
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Affiliation(s)
- Maria Smyrli
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Heraklion, 71500 Crete, Greece.
- Department of Biology, University of Crete, Heraklion, 70013 Crete, Greece.
| | - Adriana Triga
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Heraklion, 71500 Crete, Greece.
- Department of Biology, University of Crete, Heraklion, 70013 Crete, Greece.
| | - Nancy Dourala
- Fish Pathology Department, Selonda Aquaculture, 15125 Athens, Greece.
| | | | - Michael Pavlidis
- Department of Biology, University of Crete, Heraklion, 70013 Crete, Greece.
| | - Viet Ha Quoc
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Heraklion, 71500 Crete, Greece.
| | - Pantelis Katharios
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Heraklion, 71500 Crete, Greece.
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13
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Horizontal Gene Transfer and Its Association with Antibiotic Resistance in the Genus Aeromonas spp. Microorganisms 2019; 7:microorganisms7090363. [PMID: 31540466 PMCID: PMC6780555 DOI: 10.3390/microorganisms7090363] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/09/2019] [Accepted: 09/13/2019] [Indexed: 12/24/2022] Open
Abstract
The evolution of multidrug resistant bacteria to the most diverse antimicrobials known so far pose a serious problem to global public health. Currently, microorganisms that develop resistant phenotypes to multiple drugs are associated with high morbidity and mortality. This resistance is encoded by a group of genes termed ‘bacterial resistome’, divided in intrinsic and extrinsic resistome. The first one refers to the resistance displayed on an organism without previous exposure to an antibiotic not involving horizontal genetic transfer, and it can be acquired via mutations. The latter, on the contrary, is acquired exclusively via horizontal genetic transfer involving mobile genetic elements that constitute the ‘bacterial mobilome’. This transfer is mediated by three different mechanisms: transduction, transformation, and conjugation. Recently, a problem of public health due to implications in the emergence of multi-drug resistance in Aeromonas spp. strains in water environments has been described. This is derived from the genetic material transfer via conjugation events. This is important, since bacteria that have acquired antibiotic resistance in natural environments can cause infections derived from their ingestion or direct contact with open wounds or mucosal tissue, which in turn, by their resistant nature, makes their eradication complex. Implications of the emergence of resistance in Aeromonas spp. by horizontal gene transfer on public health are discussed.
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14
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Rangel LT, Marden J, Colston S, Setubal JC, Graf J, Gogarten JP. Identification and characterization of putative Aeromonas spp. T3SS effectors. PLoS One 2019; 14:e0214035. [PMID: 31163020 PMCID: PMC6548356 DOI: 10.1371/journal.pone.0214035] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 05/21/2019] [Indexed: 11/23/2022] Open
Abstract
The genetic determinants of bacterial pathogenicity are highly variable between species and strains. However, a factor that is commonly associated with virulent Gram-negative bacteria, including many Aeromonas spp., is the type 3 secretion system (T3SS), which is used to inject effector proteins into target eukaryotic cells. In this study, we developed a bioinformatics pipeline to identify T3SS effector proteins, applied this approach to the genomes of 105 Aeromonas strains isolated from environmental, mutualistic, or pathogenic contexts and evaluated the cytotoxicity of the identified effectors through their heterologous expression in yeast. The developed pipeline uses a two-step approach, where candidate Aeromonas gene families are initially selected using Hidden Markov Model (HMM) profile searches against the Virulence Factors DataBase (VFDB), followed by strict comparisons against positive and negative control datasets, greatly reducing the number of false positives. This approach identified 21 Aeromonas T3SS likely effector families, of which 8 represent known or characterized effectors, while the remaining 13 have not previously been described in Aeromonas. We experimentally validated our in silico findings by assessing the cytotoxicity of representative effectors in Saccharomyces cerevisiae BY4741, with 15 out of 21 assayed proteins eliciting a cytotoxic effect in yeast. The results of this study demonstrate the utility of our approach, combining a novel in silico search method with in vivo experimental validation, and will be useful in future research aimed at identifying and authenticating bacterial effector proteins from other genera.
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Affiliation(s)
- Luiz Thiberio Rangel
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
- Interunidades em Bioinformática, Universidade de São Paulo, São Paulo, Brasil
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
| | - Jeremiah Marden
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Sophie Colston
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - João Carlos Setubal
- Interunidades em Bioinformática, Universidade de São Paulo, São Paulo, Brasil
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
| | - Joerg Graf
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America
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15
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Liu ZG, Zheng AF, Chen MM, Lian YX, Zhang XK, Zhang SZ, Yu D, Li JK. Isolation and identification of pathogenic Aeromonas veronii from a dead Yangtze finless porpoise. DISEASES OF AQUATIC ORGANISMS 2018; 132:13-22. [PMID: 30530927 DOI: 10.3354/dao03288] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Diseases caused by Aeromonas veronii in freshwater fish have been widely reported, but other species such as aquatic mammals have probably been overlooked. Here, we identified one isolate of A. veronii from a Yangtze finless porpoise Neophocaena asiaeorientalis asiaeorientalis exhibiting disease and mortality, and subsequently confirmed its virulence in artificial infection of BALB/c mice. The bacterial isolate was identified as A. veronii based on physiological, biochemical, and phenotypic features, and homology of the 16S rRNA, cpn60, rpoB, dnaJ and gyrB genes. Our results expand the known host spectrum of A. veronii, which is of great importance for the etiology of porpoise, dolphin, and other cetacean diseases.
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Affiliation(s)
- Z G Liu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
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16
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Beka L, Fullmer MS, Colston SM, Nelson MC, Talagrand-Reboul E, Walker P, Ford B, Whitaker IS, Lamy B, Gogarten JP, Graf J. Low-Level Antimicrobials in the Medicinal Leech Select for Resistant Pathogens That Spread to Patients. mBio 2018; 9:e01328-18. [PMID: 30042201 PMCID: PMC6058295 DOI: 10.1128/mbio.01328-18] [Citation(s) in RCA: 24] [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: 06/19/2018] [Accepted: 06/25/2018] [Indexed: 02/07/2023] Open
Abstract
Fluoroquinolones (FQs) and ciprofloxacin (Cp) are important antimicrobials that pollute the environment in trace amounts. Although Cp has been recommended as prophylaxis for patients undergoing leech therapy to prevent infections by the leech gut symbiont Aeromonas, a puzzling rise in Cp-resistant (Cpr) Aeromonas infections has been reported. We report on the effects of subtherapeutic FQ concentrations on bacteria in an environmental reservoir, the medicinal leech, and describe the presence of multiple antibiotic resistance mutations and a gain-of-function resistance gene. We link the rise of CprAeromonas isolates to exposure of the leech microbiota to very low levels of Cp (0.01 to 0.04 µg/ml), <1/100 of the clinical resistance breakpoint for Aeromonas Using competition experiments and comparative genomics of 37 strains, we determined the mechanisms of resistance in clinical and leech-derived Aeromonas isolates, traced their origin, and determined that the presence of merely 0.01 µg/ml Cp provides a strong competitive advantage for Cpr strains. Deep-sequencing the Cpr-conferring region of gyrA enabled tracing of the mutation-harboring Aeromonas population in archived gut samples, and an increase in the frequency of the Cpr-conferring mutation in 2011 coincides with the initial reports of CprAeromonas infections in patients receiving leech therapy.IMPORTANCE The role of subtherapeutic antimicrobial contamination in selecting for resistant strains has received increasing attention and is an important clinical matter. This study describes the relationship of resistant bacteria from the medicinal leech, Hirudo verbana, with patient infections following leech therapy. While our results highlight the need for alternative antibiotic therapies, the rise of Cpr bacteria demonstrates the importance of restricting the exposure of animals to antibiotics approved for veterinary use. The shift to a more resistant community and the dispersion of Cpr-conferring mechanisms via mobile elements occurred in a natural setting due to the presence of very low levels of fluoroquinolones, revealing the challenges of controlling the spread of antibiotic-resistant bacteria and highlighting the importance of a holistic approach in the management of antibiotic use.
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Affiliation(s)
- Lidia Beka
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Matthew S Fullmer
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Sophie M Colston
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Michael C Nelson
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Emilie Talagrand-Reboul
- Équipe Pathogènes Hydriques Santé Environnements, UMR 5569 HSM, Université de Montpellier, Montpellier, France
- Département d'Hygiène Hospitalière, CHRU de Montpellier, Montpellier, France
| | - Paul Walker
- Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Bradley Ford
- Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Iain S Whitaker
- Institute of Life Sciences, Swansea University College of Medicine, Swansea, Wales, United Kingdom
| | - Brigitte Lamy
- Équipe Pathogènes Hydriques Santé Environnements, UMR 5569 HSM, Université de Montpellier, Montpellier, France
- Laboratoire de Bactériologie, CHRU de Montpellier, Montpellier, France
- INSERM U1065, C3M, Team 6, Nice, France
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, USA
| | - Joerg Graf
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, USA
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17
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Salmonová H, Killer J, Bunešová V, Geigerová M, Vlková E. Cultivable bacteria from Pectinatella magnifica and the surrounding water in South Bohemia indicate potential new Gammaproteobacterial, Betaproteobacterial and Firmicutes taxa. FEMS Microbiol Lett 2018; 365:4995195. [DOI: 10.1093/femsle/fny118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 05/09/2018] [Indexed: 12/17/2022] Open
Affiliation(s)
- Hana Salmonová
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, Suchdol 165 00, Czech Republic
| | - Jiří Killer
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, Suchdol 165 00, Czech Republic
- Institute of Animal Physiology and Genetics v.v.i., Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4, Krč, 142 20, Czech Republic
| | - Věra Bunešová
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, Suchdol 165 00, Czech Republic
| | - Martina Geigerová
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, Suchdol 165 00, Czech Republic
| | - Eva Vlková
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, Suchdol 165 00, Czech Republic
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18
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Lorén JG, Farfán M, Fusté MC. Species Delimitation, Phylogenetic Relationships, and Temporal Divergence Model in the Genus Aeromonas. Front Microbiol 2018; 9:770. [PMID: 29731747 PMCID: PMC5920023 DOI: 10.3389/fmicb.2018.00770] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/05/2018] [Indexed: 11/16/2022] Open
Abstract
The definition of species boundaries constitutes an important challenge in biodiversity studies. In this work we applied the Generalized Mixed Yule Coalescent (GMYC) method, which determines a divergence threshold to delimit species in a phylogenetic tree. Based on the tree branching pattern, the analysis fixes the transition threshold between speciation and the coalescent process associated with the intra-species diversification. This approach has been widely used to delineate eukaryote species and establish their diversification process from sequence data. Nevertheless, there are few examples in which this analysis has been applied to a bacterial population. Although the GMYC method was originally designed to assume a constant (Yule) model of diversification at between-species level, it was later evaluated simulating other conditions. Our aim was therefore to determine the species delineation in Aeromonas using the GMYC method and asses which model best explains the speciation process in this bacterial genus. The application of the GMYC method allowed us to clearly delineate the Aeromonas species boundaries, even in the controversial groups, such as the A. veronii or A. media species complexes.
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Affiliation(s)
- J G Lorén
- Departament de Biologia, Sanitat i Medi Ambient, Secció de Microbiologia, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain
| | - Maribel Farfán
- Departament de Biologia, Sanitat i Medi Ambient, Secció de Microbiologia, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain.,Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Barcelona, Spain
| | - M C Fusté
- Departament de Biologia, Sanitat i Medi Ambient, Secció de Microbiologia, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain.,Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Barcelona, Spain
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19
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Talagrand-Reboul E, Jumas-Bilak E, Lamy B. The Social Life of Aeromonas through Biofilm and Quorum Sensing Systems. Front Microbiol 2017; 8:37. [PMID: 28163702 PMCID: PMC5247445 DOI: 10.3389/fmicb.2017.00037] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 01/06/2017] [Indexed: 01/25/2023] Open
Abstract
Bacteria of the genus Aeromonas display multicellular behaviors herein referred to as “social life”. Since the 1990s, interest has grown in cell-to-cell communication through quorum sensing signals and biofilm formation. As they are interconnected, these two self-organizing systems deserve to be considered together for a fresh perspective on the natural history and lifestyles of aeromonads. In this review, we focus on the multicellular behaviors of Aeromonas, i.e., its social life. First, we review and discuss the available knowledge at the molecular and cellular levels for biofilm and quorum sensing. We then discuss the complex, subtle, and nested interconnections between the two systems. Finally, we focus on the aeromonad multicellular coordinated behaviors involved in heterotrophy and virulence that represent technological opportunities and applied research challenges.
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Affiliation(s)
- Emilie Talagrand-Reboul
- Équipe Pathogènes Hydriques Santé Environnements, UMR 5569 HSM, Université de MontpellierMontpellier, France; Département d'Hygiène Hospitalière, Centre Hospitalier Régional Universitaire (CHRU) de MontpellierMontpellier, France
| | - Estelle Jumas-Bilak
- Équipe Pathogènes Hydriques Santé Environnements, UMR 5569 HSM, Université de MontpellierMontpellier, France; Département d'Hygiène Hospitalière, Centre Hospitalier Régional Universitaire (CHRU) de MontpellierMontpellier, France
| | - Brigitte Lamy
- Équipe Pathogènes Hydriques Santé Environnements, UMR 5569 HSM, Université de MontpellierMontpellier, France; Département de Bactériologie, Centre Hospitalier Universitaire (CHU) de NiceNice, France
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20
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De S Jagoda SSS, Honein K, Arulkanthan A, Ushio H, Asakawa S. Genome sequencing and annotation of Aeromonas veronii strain Ae52, a multidrug-resistant isolate from septicaemic gold fish ( Carassius auratus) in Sri Lanka. GENOMICS DATA 2016; 11:46-48. [PMID: 27942459 PMCID: PMC5137324 DOI: 10.1016/j.gdata.2016.11.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 11/09/2016] [Indexed: 12/13/2022]
Abstract
Here we report the draft genome sequence and annotation of A. veronii strain Ae52 isolated from the kidney of a morbund, septicaemic gold fish (Carassius auratus) in Sri Lanka. This clinical isolate showed resistance to multiple antimicrobials; amoxicillin, neomycin, trimethoprim-sulphonamide, chloramphenicol, tetracycline, enrofloxacin, erythromycin and nitrofurantoin. The size of the draft genome is 4.56 Mbp with 58.66% of G + C content consisting 4328 coding sequences. It harbors a repertoire of putative antibiotic resistant determinants that explains the genetic basis of its resistance to various classes of antibiotics. The genome sequence has been deposited in DDBJ/EMBL/GenBank under the accession numbers BDGY01000001-BDGY01000080.
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Affiliation(s)
- S S S De S Jagoda
- Laboratory of Aquatic Molecular Biology and Biotechnology, Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; Center for Aquatic Animal Disease Diagnosis and Research, Department of Veterinary Pathobiology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Peradeniya 20400, Sri Lanka
| | - Karim Honein
- Laboratory of Marine Biochemistry, Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Appudurai Arulkanthan
- Center for Aquatic Animal Disease Diagnosis and Research, Department of Veterinary Pathobiology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Peradeniya 20400, Sri Lanka
| | - Hideki Ushio
- Laboratory of Marine Biochemistry, Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shuichi Asakawa
- Laboratory of Aquatic Molecular Biology and Biotechnology, Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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21
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Kollar P, Šmejkal K, Salmonová H, Vlková E, Lepšová-Skácelová O, Balounová Z, Rajchard J, Cvačka J, Jaša L, Babica P, Pazourek J. Assessment of Chemical Impact of Invasive Bryozoan Pectinatella magnifica on the Environment: Cytotoxicity and Antimicrobial Activity of P. magnifica Extracts. Molecules 2016; 21:E1476. [PMID: 27827926 PMCID: PMC6272939 DOI: 10.3390/molecules21111476] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 10/23/2016] [Accepted: 10/31/2016] [Indexed: 11/16/2022] Open
Abstract
Pectinatella magnifica, an invasive bryozoan, might significantly affect ecosystem balance due to its massive occurrence in many areas in Europe and other parts of the world. Biological and chemical analyses are needed to get complete information about the impact of the animal on the environment. In this paper, we aimed to evaluate in vitro cytotoxic effects of five extracts prepared from P. magnifica using LDH assay on THP-1 cell line. Antimicrobial activities of extracts against 22 different bacterial strains were tested by microdilution method. Our study showed that all extracts tested, except aqueous portion, demonstrated LD50 values below 100 μg/mL, which indicates potential toxicity. The water extract of P. magnifica with LD50 value of 250 μg/mL also shows potentially harmful effects. Also, an environmental risk resulting from the presence and increasing biomass of potentially toxic benthic cyanobacteria in old colonies should not be underestimated. Toxicity of Pectinatella extracts could be partially caused by presence of Aeromonas species in material, since we found members of these genera as most abundant bacteria associated with P. magnifica. Furthermore, P. magnifica seems to be a promising source of certain antimicrobial agents. Its methanolic extract, hexane, and chloroform fractions possessed selective inhibitory effect on some potential pathogens and food spoiling bacteria in the range of MIC 0.5-10 mg/mL. Future effort should be made to isolate and characterize the content compounds derived from P. magnifica, which could help to identify the substance(s) responsible for the toxic effects of P. magnifica extracts.
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Affiliation(s)
- Peter Kollar
- Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Palackého tř. 1946/1, Brno 61242, Czech Republic.
| | - Karel Šmejkal
- Department of Natural Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Palackého tř. 1946/1, Brno 61242, Czech Republic.
| | - Hana Salmonová
- Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, 16521, Czech Republic.
| | - Eva Vlková
- Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, 16521, Czech Republic.
| | - Olga Lepšová-Skácelová
- Department of Botany, Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 31, České Budějovice 37005, Czech Republic.
| | - Zuzana Balounová
- Department of Biological Studies, Faculty of Agriculture, University of South Bohemia in České Budějovice, Studentská 13, České Budějovice 37005, Czech Republic.
| | - Josef Rajchard
- Department of Biological Studies, Faculty of Agriculture, University of South Bohemia in České Budějovice, Studentská 13, České Budějovice 37005, Czech Republic.
| | - Josef Cvačka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, Prague 16610, Czech Republic.
| | - Libor Jaša
- RECETOX-Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Kamenice 753/5, Brno 60200, Czech Republic.
- Department of Experimental Phycology and Ecotoxicology, Institute of Botany, Academy of Sciences of the Czech Republic, Lidická 25/27, Brno 60200, Czech Republic.
| | - Pavel Babica
- RECETOX-Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Kamenice 753/5, Brno 60200, Czech Republic.
- Department of Experimental Phycology and Ecotoxicology, Institute of Botany, Academy of Sciences of the Czech Republic, Lidická 25/27, Brno 60200, Czech Republic.
| | - Jiří Pazourek
- Department of Chemical Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Palackého tř. 1946/1, Brno 61242, Czech Republic.
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Marden JN, McClure EA, Beka L, Graf J. Host Matters: Medicinal Leech Digestive-Tract Symbionts and Their Pathogenic Potential. Front Microbiol 2016; 7:1569. [PMID: 27790190 PMCID: PMC5061737 DOI: 10.3389/fmicb.2016.01569] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/20/2016] [Indexed: 12/31/2022] Open
Abstract
Digestive-tract microbiota exert tremendous influence over host health. Host-symbiont model systems are studied to investigate how symbioses are initiated and maintained, as well as to identify host processes affected by resident microbiota. The medicinal leech, Hirudo verbana, is an excellent model to address such questions owing to a microbiome that is consistently dominated by two species, Aeromonas veronii and Mucinivorans hirudinis, both of which are cultivable and have sequenced genomes. This review outlines current knowledge about the dynamics of the H. verbana microbiome. We discuss in depth the factors required for A. veronii colonization and proliferation in the leech crop and summarize the current understanding of interactions between A. veronii and its annelid host. Lastly, we discuss leech usage in modern medicine and highlight how leech-therapy associated infections, often attributable to Aeromonas spp., are of growing clinical concern due in part to an increased prevalence of fluoroquinolone resistant strains.
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Affiliation(s)
- Jeremiah N Marden
- Department of Molecular and Cell Biology, University of Connecticut, Storrs CT, USA
| | - Emily A McClure
- Department of Molecular and Cell Biology, University of Connecticut, Storrs CT, USA
| | - Lidia Beka
- Department of Molecular and Cell Biology, University of Connecticut, Storrs CT, USA
| | - Joerg Graf
- Department of Molecular and Cell Biology, University of Connecticut, StorrsCT, USA; Institute for Systems Genomics, University of Connecticut, StorrsCT, USA
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Xu X, Sivaramasamy E, Jin S, Li F, Xiang J. Establishment and characterization of a skin epidermal cell line from mud loach, Misgurnus anguillicaudatus, (MASE) and its interaction with three bacterial pathogens. FISH & SHELLFISH IMMUNOLOGY 2016; 55:444-451. [PMID: 27288257 DOI: 10.1016/j.fsi.2016.06.009] [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: 02/04/2016] [Revised: 06/01/2016] [Accepted: 06/06/2016] [Indexed: 06/06/2023]
Abstract
A continuous skin epidermal cell line from mud Loach (Misgurnus anguillicaudatus) (MASE cell line) was established with its application in bacteria infection demonstrated in this study. Primary MASE cell culture was initiated at 26 °C in Dulbecco's modified Eagle medium/F12 medium (1:1; pH7.2) supplemented with 20% fetal bovine serum (FBS). The primary MASE cells in spindle morphology proliferated into a confluent monolayer within 2 weeks, and were continuously subcultured even in 10% FBS- DMEM/F12 after 10 passages. Impacts of medium and temperature on the growth of the cells were examined. The optimum growth was found in DMEM/F12 with 20% FBS and at 26 °C. The MASE cells have been subcultured steadily over Passage 90 with a population doubling time of 53.3 h at Passage 60. Chromosome analysis revealed that 60.5% of MASE cells at Passage 60 maintained the normal diploid chromosome number (50) with a normal karyotype of 10m+4sm + 36t. Bacteria from the three species (Aeromonas veronii, Vibrio parahaemolyticus and Escherichia coli) were used to investigate the interactions between bacteria and cellular hosts. The three strains could be attached to the MASE cells and replicate at different levels. A. veronii could induce apoptosis in the MASE cells, with highest adherence rate among the three strains, whereas V. parahaemolyticus could cause highest cell death rate through a non-apoptotic cell death pathway, with high level of replication. The results revealed that different bacteria could interact with the MASE cells in different manners, and divergent pathways might lie in mediating cell death when cellular hosts confronted with pathogen infection. Therefore, the MASE cell line may serve as a useful tool for studying the interaction between skin bacteria and fish cells.
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Affiliation(s)
- Xiaohui Xu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao, 266071, China
| | - Elayaraja Sivaramasamy
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao, 266071, China
| | - Songjun Jin
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao, 266071, China
| | - Fuhua Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao, 266071, China
| | - Jianhai Xiang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao, 266071, China.
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Utility of Greater Wax Moth Larva (Galleria mellonella) for Evaluating the Toxicity and Efficacy of New Antimicrobial Agents. ADVANCES IN APPLIED MICROBIOLOGY 2016; 78:25-53. [PMID: 22305092 DOI: 10.1016/b978-0-12-394805-2.00002-6] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
There is an urgent need for new antimicrobial agents to combat infections caused by drug-resistant pathogens. Once a compound is shown to be effective in vitro, it is necessary to evaluate its efficacy in an animal infection model. Typically, this is achieved using a mammalian model, but such experiments are costly, time consuming, and require full ethical consideration. Hence, cheaper and ethically more acceptable invertebrate models of infection have been introduced, including the larvae of the greater wax moth Galleria mellonella. Invertebrates have an immune system that is functionally similar to the innate immune system of mammals, and often identical virulence and pathogenicity factors are used by human pathogenic microbes to infect wax moth larvae and mammals. Moreover, the virulence of many human pathogens is comparable in wax moth larvae and mammals. Using key examples from the literature, this chapter highlights the benefits of using the wax moth larva model to provide a rapid, inexpensive, and reliable evaluation of the toxicity and efficacy of new antimicrobial agents in vivo and prior to the use of more expensive mammalian models. This simple insect model can bridge the gap between in vitro studies and mammalian experimentation by screening out compounds with a low likelihood of success, while providing greater justification for further studies in mammalian systems. Thus, broader implementation of the wax moth larva model into anti-infective drug discovery and development programs could reduce the use of mammals during preclinical assessments and the overall cost of drug development.
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Characterization of Virulence Properties of Aeromonas veronii Isolated from Diseased Gibel Carp (Carassius gibelio). Int J Mol Sci 2016; 17:496. [PMID: 27043558 PMCID: PMC4848952 DOI: 10.3390/ijms17040496] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/16/2016] [Accepted: 03/29/2016] [Indexed: 11/17/2022] Open
Abstract
Aeromonas veronii is a kind of opportunistic pathogen to fish and humans, significantly impending aquaculture production. Recently, we isolated two A. veronii strains, named GYC1 and GYC2, from diseased Gibel carp (Carassiusgibelio) in China. Based on gyrB (DNA gyrase B subunit) genes of GYC1 and GYC2, the constructed phylogenetic tree showed that the two strains were clustered with A. veronii. Sixteen virulence genes related to the pathogenicity of Aeromonas spp. were subjected to PCR assay. The genes of ompAI, ompAII, lafA, act, aer, fla, gcaT and acg were detected in the two strains, while genes of hly, ahp, lip, ast and alt were not detected. Additionally, genes eprCAI, ela and exu were only detected in the strain GYC1. Furthermore, the results of extracellular enzyme analysis revealed that the two isolates can produce hemolysin, caseinase, esterase, amylase and lecithinase, which were closely related to the pathogenicity of the two strains. However, the results showed that there was no gelatinase activity in either strain. According to the antibiotic resistant assay, the two strains were sensitive to cephalosporins and aminoglycosides, while they were resistant to penicillins and quinolones. Through this study, the virulence characteristics, including virulence genes and extracellular enzymes, the pathogenicity of A. veronii was clarified, enhancing the understanding about this pathogenic bacterium and providing the theoretical basis in disease control.
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Sanglas A, Albarral V, Farfán M, Lorén JG, Fusté MC. Direct evidence of recombination in the recA gene of Aeromonas bestiarum. Syst Appl Microbiol 2016; 39:106-14. [PMID: 26934994 DOI: 10.1016/j.syapm.2016.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 01/22/2016] [Accepted: 01/27/2016] [Indexed: 11/25/2022]
Abstract
Two hundred and twenty-one strains representative of all Aeromonas species were characterized using the recA gene sequence, assessing its potential as a molecular marker for the genus Aeromonas. The inter-species distance values obtained demonstrated that recA has a high discriminatory power. Phylogenetic analysis, based on full-length gene nucleotide sequences, revealed a robust topology with clearly separated clusters for each species. The maximum likelihood tree showed the Aeromonas bestiarum strains in a well-defined cluster, containing a subset of four strains of different geographical origins in a deep internal branch. Data analysis provided strong evidence of recombination at the end of the recA sequences in these four strains. Intergenomic recombination corresponding to partial regions of the two adjacent genes recA and recX (248 bp) was identified between A. bestiarum (major parent) and Aeromonas eucrenophila (minor parent). The low number of recombinant strains detected (1.8%) suggests that horizontal flow between recA sequences is relatively uncommon in this genus. Moreover, only a few nucleotide differences were detected among these fragments, indicating that recombination has occurred recently. Finally, we also determined if the recombinant fragment could have influenced the structure and basic functions of the RecA protein, comparing models reconstructed from the translated amino acid sequences of our A. bestiarum strains with known Escherichia coli RecA structures.
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Affiliation(s)
- Ariadna Sanglas
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain.
| | - Vicenta Albarral
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain.
| | - Maribel Farfán
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain; Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain.
| | - J Gaspar Lorén
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain.
| | - M Carmen Fusté
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain; Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain.
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Havixbeck JJ, Wong ME, More Bayona JA, Barreda DR. Multi-parametric analysis of phagocyte antimicrobial responses using imaging flow cytometry. J Immunol Methods 2015; 423:85-92. [PMID: 25862969 DOI: 10.1016/j.jim.2015.03.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 03/13/2015] [Accepted: 03/28/2015] [Indexed: 01/28/2023]
Abstract
We feature a multi-parametric approach based on an imaging flow cytometry platform for examining phagocyte antimicrobial responses against the gram-negative bacterium Aeromonas veronii. This pathogen is known to induce strong inflammatory responses across a broad range of animal species, including humans. We examined the contribution of A. veronii to the induction of early phagocyte inflammatory processes in RAW 264.7 murine macrophages in vitro. We found that A. veronii, both in live or heat-killed forms, induced similar levels of macrophage activation based on NF-κB translocation. Although these macrophages maintained high levels of viability following heat-killed or live challenges with A. veronii, we identified inhibition of macrophage proliferation as early as 1h post in vitro challenge. The characterization of phagocytic responses showed a time-dependent increase in phagocytosis upon A. veronii challenge, which was paired with a robust induction of intracellular respiratory burst responses. Interestingly, despite the overall increase in the production of reactive oxygen species (ROS) among RAW 264.7 macrophages, we found a significant reduction in the production of ROS among the macrophage subset that had bound A. veronii. Phagocytic uptake of the pathogen further decreased ROS production levels, even beyond those of unstimulated controls. Overall, this multi-parametric imaging flow cytometry-based approach allowed for segregation of unique phagocyte sub-populations and examination of their downstream antimicrobial responses, and should contribute to improved understanding of phagocyte responses against Aeromonas and other pathogens.
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Affiliation(s)
- Jeffrey J Havixbeck
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - Michael E Wong
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - Juan A More Bayona
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - Daniel R Barreda
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2P5, Canada; Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
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Duarte AS, Cavaleiro E, Pereira C, Merino S, Esteves AC, Duarte EP, Tomás JM, Correia AC. Aeromonas piscicola AH-3 expresses an extracellular collagenase with cytotoxic properties. Lett Appl Microbiol 2014; 60:288-97. [PMID: 25443157 DOI: 10.1111/lam.12373] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 11/10/2014] [Accepted: 11/26/2014] [Indexed: 01/01/2023]
Abstract
UNLABELLED The aim of this study was to investigate the presence and the phenotypic expression of a gene coding for a putative collagenase. This gene (AHA_0517) was identified in Aeromonas hydrophila ATCC 7966 genome and named colAh. We constructed and characterized an Aeromonas piscicola AH-3::colAh knockout mutant. Collagenolytic activity of the wild-type and mutant strains was determined, demonstrating that colAh encodes for a collagenase. ColAh-collagen interaction was assayed by Far-Western blot, and cytopathic effects were investigated in Vero cells. We demonstrated that ColAh is a gluzincin metallopeptidase (approx. 100 kDa), able to cleave and physically interact with collagen, that contributes for Aeromonas collagenolytic activity and cytotoxicity. ColAh possess the consensus HEXXH sequence and a glutamic acid as the third zinc binding positioned downstream the HEXXH motif, but has low sequence similarity and distinct domain architecture to the well-known clostridial collagenases. In addition, these results highlight the importance of exploring new microbial collagenases that may have significant relevance for the health and biotechnological industries. SIGNIFICANCE AND IMPACT OF THE STUDY Collagenases play a central role in processes where collagen digestion is needed, for example host invasion by pathogenic micro-organisms. We identified a new collagenase from Aeromonas using an integrated in silico/in vitro strategy. This enzyme is able to bind and cleave collagen, contributes for AH-3 cytotoxicity and shares low similarity with known bacterial collagenases. This is the first report of an enzyme belonging to the gluzincin subfamily of the M9 family of peptidases in Aeromonas. This study increases the current knowledge on collagenolytic enzymes bringing new perspectives for biotechnology/medical purposes.
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Affiliation(s)
- A S Duarte
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal
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29
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Bioinformatic genome comparisons for taxonomic and phylogenetic assignments using Aeromonas as a test case. mBio 2014; 5:e02136. [PMID: 25406383 PMCID: PMC4251997 DOI: 10.1128/mbio.02136-14] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Prokaryotic taxonomy is the underpinning of microbiology, as it provides a framework for the proper identification and naming of organisms. The “gold standard” of bacterial species delineation is the overall genome similarity determined by DNA-DNA hybridization (DDH), a technically rigorous yet sometimes variable method that may produce inconsistent results. Improvements in next-generation sequencing have resulted in an upsurge of bacterial genome sequences and bioinformatic tools that compare genomic data, such as average nucleotide identity (ANI), correlation of tetranucleotide frequencies, and the genome-to-genome distance calculator, or in silico DDH (isDDH). Here, we evaluate ANI and isDDH in combination with phylogenetic studies using Aeromonas, a taxonomically challenging genus with many described species and several strains that were reassigned to different species as a test case. We generated improved, high-quality draft genome sequences for 33 Aeromonas strains and combined them with 23 publicly available genomes. ANI and isDDH distances were determined and compared to phylogenies from multilocus sequence analysis of housekeeping genes, ribosomal proteins, and expanded core genes. The expanded core phylogenetic analysis suggested relationships between distant Aeromonas clades that were inconsistent with studies using fewer genes. ANI values of ≥96% and isDDH values of ≥70% consistently grouped genomes originating from strains of the same species together. Our study confirmed known misidentifications, validated the recent revisions in the nomenclature, and revealed that a number of genomes deposited in GenBank are misnamed. In addition, two strains were identified that may represent novel Aeromonas species. Improvements in DNA sequencing technologies have resulted in the ability to generate large numbers of high-quality draft genomes and led to a dramatic increase in the number of publically available genomes. This has allowed researchers to characterize microorganisms using genome data. Advantages of genome sequence-based classification include data and computing programs that can be readily shared, facilitating the standardization of taxonomic methodology and resolving conflicting identifications by providing greater uniformity in an overall analysis. Using Aeromonas as a test case, we compared and validated different approaches. Based on our analyses, we recommend cutoff values for distance measures for identifying species. Accurate species classification is critical not only to obviate the perpetuation of errors in public databases but also to ensure the validity of inferences made on the relationships among species within a genus and proper identification in clinical and veterinary diagnostic laboratories.
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30
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Hitchhiking of host biology by beneficial symbionts enhances transmission. Sci Rep 2014; 4:5825. [PMID: 25059557 PMCID: PMC5376049 DOI: 10.1038/srep05825] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 07/02/2014] [Indexed: 12/30/2022] Open
Abstract
Transmission plays a key role in the evolution of symbiosis. Mixed mode transmission combines horizontal and vertical mechanisms for symbiont acquisition. However, features that enable mixed transmission are poorly understood. Here, we determine the mechanistic basis for the recruitment of the beneficial bacterium, Aeromonas veronii by the leech, Hirudo verbana. We demonstrate that host mucosal secretions complement imperfect symbiont vertical transmission. First, we show that the A. veronii population within secretions originates from the host digestive tract and proliferates synchronously with shedding frequency, demonstrating the coupling of partner biology. Furthermore, leeches are attracted to these castings with oral contact proving sufficient for symbiont transmission. Leech attraction to mucus is not affected by the symbiont state of either the host or mucus, suggesting that A. veronii exploits preexisting host behavior and physiological traits. A dual transmission mode, integrating multiple layers of host contributions, may prove evolutionarily advantageous for a wide range of symbioses. Using such a strategy, host infection is ensured, while also providing access to a higher genetic diversity of symbionts. Countless host-associated microbes exhibit mixed mode transmission, supporting the use of the leech symbiosis as a model for enhancing our understanding of the specificity, establishment and persistence of microbiotas.
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31
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Liu XL, Liu SL, Liu M, Kong BH, Liu L, Li YH. A primary assessment of the endophytic bacterial community in a xerophilous moss (Grimmia montana) using molecular method and cultivated isolates. Braz J Microbiol 2014; 45:163-73. [PMID: 24948927 PMCID: PMC4059291 DOI: 10.1590/s1517-83822014000100022] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 04/01/2013] [Indexed: 11/30/2022] Open
Abstract
Investigating the endophytic bacterial community in special moss species is fundamental to understanding the microbial-plant interactions and discovering the bacteria with stresses tolerance. Thus, the community structure of endophytic bacteria in the xerophilous moss Grimmia montana were estimated using a 16S rDNA library and traditional cultivation methods. In total, 212 sequences derived from the 16S rDNA library were used to assess the bacterial diversity. Sequence alignment showed that the endophytes were assigned to 54 genera in 4 phyla (Proteobacteria, Firmicutes, Actinobacteria and Cytophaga/Flexibacter/Bacteroids). Of them, the dominant phyla were Proteobacteria (45.9%) and Firmicutes (27.6%), the most abundant genera included Acinetobacter, Aeromonas, Enterobacter, Leclercia, Microvirga, Pseudomonas, Rhizobium, Planococcus, Paenisporosarcina and Planomicrobium. In addition, a total of 14 species belonging to 8 genera in 3 phyla (Proteobacteria, Firmicutes, Actinobacteria) were isolated, Curtobacterium, Massilia, Pseudomonas and Sphingomonas were the dominant genera. Although some of the genera isolated were inconsistent with those detected by molecular method, both of two methods proved that many different endophytic bacteria coexist in G. montana. According to the potential functional analyses of these bacteria, some species are known to have possible beneficial effects on hosts, but whether this is the case in G. montana needs to be confirmed.
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Affiliation(s)
- Xiao Lei Liu
- College of Life Science Capital Normal University Haidian DistrictBeijing China
| | - Su Lin Liu
- College of Life Science Capital Normal University Haidian DistrictBeijing China
| | - Min Liu
- College of Life Science Capital Normal University Haidian DistrictBeijing China
| | - Bi He Kong
- College of Life Science Capital Normal University Haidian DistrictBeijing China
| | - Lei Liu
- College of Life Science Capital Normal University Haidian DistrictBeijing China
| | - Yan Hong Li
- College of Life Science Capital Normal University Haidian DistrictBeijing China
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Nydam ML, Hoang TA, Shanley KM, De Tomaso AW. Molecular evolution of a polymorphic HSP40-like protein encoded in the histocompatibility locus of an invertebrate chordate. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2013; 41:128-136. [PMID: 23542705 DOI: 10.1016/j.dci.2013.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 03/09/2013] [Accepted: 03/12/2013] [Indexed: 06/02/2023]
Abstract
Allorecognition, the ability to distinguish self from non-self, occurs in most organisms. Despite the ubiquity of the allorecognition process, the genetic basis for allorecognition remains unexplored in most taxa outside vertebrates and flowering plants. The allorecognition system in the colonial ascidian Botryllus schlosseri is a notable exception. We have recently identified a polymorphic gene within the fuhc locus that may play a role in allorecognition. The encoded protein, called Hsp40-L, is a Type II member of the J-protein family which usually functions as a co-chaperone with Hsp70. While many of the residues that interact with Hsp70 are conserved in Hsp40-L, it may not be a housekeeping protein because it is surprisingly polymorphic and expressed in the ampullae, the site of allorecognition. While the majority of the Hsp40-L protein appears to evolve under purifying selection, a section of the C-terminal region likely experiences balancing/directional selection, characteristic of other allorecognition proteins.
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Affiliation(s)
- Marie L Nydam
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
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Martino ME, Fasolato L, Montemurro F, Novelli E, Cardazzo B. Aeromonasspp.: ubiquitous or specialized bugs? Environ Microbiol 2013; 16:1005-18. [DOI: 10.1111/1462-2920.12215] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/10/2013] [Accepted: 07/10/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Maria Elena Martino
- Department of Comparative Biomedicine and Food Science; University of Padova; Legnaro 35020 Italy
| | - Luca Fasolato
- Department of Comparative Biomedicine and Food Science; University of Padova; Legnaro 35020 Italy
| | - Filomena Montemurro
- Department of Comparative Biomedicine and Food Science; University of Padova; Legnaro 35020 Italy
| | - Enrico Novelli
- Department of Comparative Biomedicine and Food Science; University of Padova; Legnaro 35020 Italy
| | - Barbara Cardazzo
- Department of Comparative Biomedicine and Food Science; University of Padova; Legnaro 35020 Italy
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Huddleston JR, Brokaw JM, Zak JC, Jeter RM. Natural transformation as a mechanism of horizontal gene transfer among environmental Aeromonas species. Syst Appl Microbiol 2013; 36:224-34. [PMID: 23541366 DOI: 10.1016/j.syapm.2013.01.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 01/15/2013] [Accepted: 01/20/2013] [Indexed: 10/27/2022]
Abstract
Aeromonas species are common inhabitants of aquatic environments and relevant as human pathogens. Their potential as pathogens may be related in part to lateral transfer of genes associated with toxin production, biofilm formation, antibiotic resistance, and other virulence determinants. Natural transformation has not been characterized in aeromonads. DNA from wild-type, prototrophic strains that had been isolated from environmental sources was used as donor DNA in transformation assays with auxotrophs as the recipients. Competence was induced in 20% nutrient broth during the stationary phase of growth. Optimal transformation assay conditions for one chosen isolate were in Tris buffer with magnesium or calcium, pH 5-8, and a saturating concentration of 0.5 μg of DNA per assay (3.3 ng of DNA μl⁻¹) at 30°C. Sodium was also required and could not be replaced with ammonium, potassium, or lithium. The maximal transformation frequency observed was 1.95 × 10⁻³ transformants (recipient cell)⁻¹. A survey of environmental Aeromonas auxotrophic recipients (n=37), assayed with donor DNA from other wild-type environmental aeromonads under optimal assay conditions, demonstrated that 73% were able to act as recipients, and 100% were able to act as donors to at least some other aeromonads. Three different transformation groups were identified based on each isolates' ability to transform other strains with its DNA. The transformation groups roughly corresponded to phylogenetic groups. These results demonstrate that natural transformation is a general property of Aeromonas environmental isolates with implications for the genetic structures of coincident Aeromonas populations.
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Affiliation(s)
- Jennifer R Huddleston
- Biology Department, ACU Box 27868, Abilene Christian University, Abilene, Texas 79699, USA.
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Utility of insects for studying human pathogens and evaluating new antimicrobial agents. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2013; 135:1-25. [PMID: 23604210 DOI: 10.1007/10_2013_194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
Insect models, such as Galleria mellonella and Drosophila melanogaster have significant ethical, logistical, and economic advantages over mammalian models for the studies of infectious diseases. Using these models, various pathogenic microbes have been studied and many novel virulence genes have been identified. Notably, because insects are susceptible to a wide variety of human pathogens and have immune responses similar to those of mammals, they offer the opportunity to understand innate immune responses against human pathogens better. It is important to note that insect pathosystems have also offered a simple strategy to evaluate the efficacy and toxicity of many antimicrobial agents. Overall, insect models provide a rapid, inexpensive, and reliable way as complementary hosts to conventional vertebrate animal models to study pathogenesis and antimicrobial agents.
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Nagar V, Shashidhar R, Bandekar JR. Characterization of Aeromonas strains isolated from Indian foods using rpoD gene sequencing and whole cell protein analysis. World J Microbiol Biotechnol 2012; 29:745-52. [DOI: 10.1007/s11274-012-1212-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 11/10/2012] [Indexed: 10/27/2022]
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Knowing your friends: invertebrate innate immunity fosters beneficial bacterial symbioses. Nat Rev Microbiol 2012; 10:815-27. [PMID: 23147708 DOI: 10.1038/nrmicro2894] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The innate immune system is present in all animals and is a crucial first line of defence against pathogens. However, animals also harbour large numbers of beneficial microorganisms that can be housed in the digestive tract, in specialized organs or on tissue surfaces. Although invertebrates lack conventional antibody-based immunity, they are capable of eliminating pathogens and, perhaps more importantly, discriminating them from other microorganisms. This Review examines the interactions between the innate immune systems of several model invertebrates and the symbionts of these organisms, and addresses the central question of how these long-lived and specific associations are established and maintained.
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van Iersel L. Basic Phylogenetic Combinatorics.— Andreas Dress, Katharina T. Huber, Jacobus Koolen, Vincent Moulton, and Andreas Spillner. Syst Biol 2012. [DOI: 10.1093/sysbio/sys082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Leo van Iersel
- Centrum Wiskunde & Informatica, Science Park 123, 1098 XG Amsterdam, Netherlands; E-mail:
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Roger F, Lamy B, Jumas-Bilak E, Kodjo A, Marchandin H. Ribosomal multi-operon diversity: an original perspective on the genus Aeromonas. PLoS One 2012; 7:e46268. [PMID: 23032081 PMCID: PMC3459834 DOI: 10.1371/journal.pone.0046268] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/28/2012] [Indexed: 12/31/2022] Open
Abstract
16S rRNA gene (rrs) is considered of low taxonomic interest in the genus Aeromonas. Here, 195 Aeromonas strains belonging to populations structured by multilocus phylogeny were studied using an original approach that considered Ribosomal Multi-Operon Diversity. This approach associated pulsed-field gel electrophoresis (PFGE) to assess rrn operon number and distribution across the chromosome and PCR-temporal temperature gel electrophoresis (TTGE) to assess rrs V3 region heterogeneity. Aeromonads harbored 8 to 11 rrn operons, 10 operons being observed in more than 92% of the strains. Intraspecific variability was low or nul except for A. salmonicida and A. aquariorum suggesting that large chromosomic rearrangements might occur in these two species while being extremely rarely encountered in the evolution of other taxa. rrn operon number at 8 as well as PFGE patterns were shown valuable for taxonomic purpose allowing resolution of species complexes. PCR-TTGE revealed a high rate of strains (41.5%) displaying intragenomic rrs heterogeneity. Strains isolated from human samples more frequently displayed intragenomic heterogeneity than strains recovered from non-human and environmental specimens. Intraspecific variability ranged from 0 to 76.5% of the strains. The observation of species-specific TTGE bands, the recovery of identical V3 regions in different species and the variability of intragenomic heterogeneity (1-13 divergent nucleotides) supported the occurrence of mutations and horizontal transfer in aeromonad rrs evolution. Altogether, the presence of a high number of rrn operon, the high proportion of strains harboring divergent rrs V3 region and the previously demonstrated high level of genetic diversity argued in favor of highly adaptative capabilities of aeromonads. Outstanding features observed for A. caviae supported the ongoing process of adaptation to a specialized niche represented by the gut, previously hypothesized. 16S rRNA gene is an informative marker in the genus Aeromonas for both evolutionary and polyphasic taxonomic studies provided that multi-operon fingerprinting approaches are used.
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Affiliation(s)
- Frédéric Roger
- UMR 5119 ECOSYM, Equipe Pathogènes et Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université Montpellier 1, Montpellier, France
| | - Brigitte Lamy
- UMR 5119 ECOSYM, Equipe Pathogènes et Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université Montpellier 1, Montpellier, France
- Laboratoire de Bactériologie, Hôpital Arnaud de Villeneuve, Centre Hospitalier Régional Universitaire de Montpellier, Montpellier, France
- Groupe d’Etude Français des Aeromonas (GFA), Lyon, France
| | - Estelle Jumas-Bilak
- UMR 5119 ECOSYM, Equipe Pathogènes et Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université Montpellier 1, Montpellier, France
- Laboratoire d’Hygiène hospitalière, Centre Hospitalier Régional Universitaire de Montpellier, Montpellier, France
| | - Angeli Kodjo
- Groupe d’Etude Français des Aeromonas (GFA), Lyon, France
- CNRS UMR 5557 Ecologie microbienne, VetAgro Sup Campus vétérinaire de Lyon, Université Claude Bernard Lyon 1, Marcy-l’Étoile, France
| | | | - Hélène Marchandin
- UMR 5119 ECOSYM, Equipe Pathogènes et Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université Montpellier 1, Montpellier, France
- Laboratoire de Bactériologie, Hôpital Arnaud de Villeneuve, Centre Hospitalier Régional Universitaire de Montpellier, Montpellier, France
- * E-mail:
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Characterization and virulence potential of phenotypically diverse Aeromonas veronii isolates recovered from moribund freshwater ornamental fishes of Kerala, India. Antonie van Leeuwenhoek 2012; 103:53-67. [DOI: 10.1007/s10482-012-9786-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/27/2012] [Indexed: 12/19/2022]
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Bomar L, Graf J. Investigation into the physiologies of Aeromonas veronii in vitro and inside the digestive tract of the medicinal leech using RNA-seq. THE BIOLOGICAL BULLETIN 2012; 223:155-166. [PMID: 22983040 PMCID: PMC3732745 DOI: 10.1086/bblv223n1p155] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Host-associated microbial communities are widespread in nature and vital to the health and fitness of the host. Deciphering the physiology of the microbiome in vivo is critical to understanding the molecular basis of the symbiosis. Recently, the development and application of high-throughput sequencing techniques, particularly RNA-seq, for studying microbial communities has enabled researchers to address not only which microbes are present in a given community but also how the community functions. For microbes that can also be cultivated in the laboratory, RNA-seq provides the opportunity to identify genes that are differentially expressed during symbiosis by comparing in vitro to in vivo transcriptomes. In the current study, we used RNA-seq to identify genes expressed by the digestive-tract microbiome of the medicinal leech, Hirudo verbana, and by one of the two dominant symbionts, Aeromonas veronii, in a rich medium. We used a comparative approach to identify genes differentially expressed during symbiosis and gain insight into the symbiont's physiology in vivo. Notable findings include evidence for the symbionts experiencing environmental stress, performing arginine catabolism, and expressing noncoding RNAs that are implicated in stationary phase survival, a state in which A. veronii persists for months within the host.
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Affiliation(s)
| | - Joerg Graf
- To whom correspondence should be addressed.
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42
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Siekoula-Nguedia C, Blanc G, Duchaud E, Calvez S. Genetic diversity of Flavobacterium psychrophilum isolated from rainbow trout in France: predominance of a clonal complex. Vet Microbiol 2012; 161:169-78. [PMID: 22871298 DOI: 10.1016/j.vetmic.2012.07.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 07/10/2012] [Accepted: 07/12/2012] [Indexed: 01/09/2023]
Abstract
Flavobacterium psychrophilum is the causative agent of "bacterial cold water disease" and "rainbow trout fry syndrome" in salmonid farming worldwide. These diseases, especially rainbow trout fry syndrome, are among the main hazards for French aquaculture. In this study, a multilocus sequence typing approach (MLST) was used to evaluate the genetic diversity of this bacterium. Seven housekeeping genes in a set of 66 isolates were investigated. They were recently collected from rainbow trout during clinical episodes in French farms from the two main geographical areas of production. A total of 5808 bp of sequence were analyzed for each isolate and showed relatively low levels of gene (H=0.4313) and nucleotide (π×100=0.31%) diversities. MLST identified 15 sequence types (STs), of which 14 have never been described. eBURST analysis separated the 15 STs in one clonal complex of 8 genetically related STs (with ST2 as founder) and 7 singletons. Genetic diversity was largely due to recombination, as demonstrated by a pairwise homoplasy index (PHI=5.35×10(-9)) significantly different from zero (p<0.05). The evolution of standardized association index (I(A)(S)) (all isolates: 0.6088, p<0.05; single representative of STs: 0.4567, p<0.05; and clusters of STs: 0.084, p>0.05), showed an epidemic structure of the population. These results emphasized the expansion of a limited number of dominant genetic variants in French clinical F. psychrophilum isolates from a single host species, with no geographic relationships.
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Affiliation(s)
- C Siekoula-Nguedia
- INRA, UMR1300 Biologie, Epidémiologie et Analyse de Risque en santé animale, BP 40706, F-44307 Nantes, France
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Goffredi SK, Morella NM, Pulcrano ME. Affiliations between bacteria and marine fish leeches (Piscicolidae), with emphasis on a deep-sea species from Monterey Canyon, CA. Environ Microbiol 2012; 14:2429-44. [PMID: 22681178 DOI: 10.1111/j.1462-2920.2012.02798.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Leeches within the Piscicolidae are of great numerical and taxonomic importance, yet little is known about bacteria that associate with this diverse group of blood-feeding marine parasites of fish and elasmobranchs. We focused primarily on the bacteria from a deep-sea leech species of unknown identity, collected at ∼ 600 m depth in Monterey Canyon, CA, along with two shallow-living leech genera, Austrobdella and Branchellion, from Los Angeles Harbor, CA. Molecular analysis of all five leech species revealed a dominance of gammaproteobacteria, which were distinct from each other and from previously reported freshwater leech symbionts. Bacteria related to members of the genus Psychromonas (99% similarity in 16S rRNA) were dominant in the deep-sea leech species (80-94% of recovered ribotypes) collected over 19 months from two different locations. Psychromonas was not detected in cocoons or 2-16 week-old juveniles, suggesting that acquisition is via the environment at a later stage. Transmission electron microscopy did, however, reveal abundant bacteria-like cells near areas of thinning of the juvenile epithelial surface, as well as Psychromonas sparsely distributed internally. Electron and fluorescence in situ microscopy of adults also showed Psychromonas-like bacteria concentrated within the crop. Despite the apparent non-transient nature of the association between Psychromonas and the deep-sea leech, their functional role, if any, is not known. The prevalence, however, of an abundant bacterial genus in one piscicolid leech species, as well as the presence of a dominant bacterial species in singular observations of four additional marine species, suggests that members of the Piscicolidae, possibly basal within the class Hirudinea, form specific alliances with microbes.
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Affiliation(s)
- S K Goffredi
- Biology Department, Occidental College, Los Angeles, CA, USA.
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Mao F, Williams D, Zhaxybayeva O, Poptsova M, Lapierre P, Gogarten JP, Xu Y. Quartet decomposition server: a platform for analyzing phylogenetic trees. BMC Bioinformatics 2012; 13:123. [PMID: 22676320 PMCID: PMC3447714 DOI: 10.1186/1471-2105-13-123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 06/07/2012] [Indexed: 11/11/2022] Open
Abstract
Background The frequent exchange of genetic material among prokaryotes means that extracting a majority or plurality phylogenetic signal from many gene families, and the identification of gene families that are in significant conflict with the plurality signal is a frequent task in comparative genomics, and especially in phylogenomic analyses. Decomposition of gene trees into embedded quartets (unrooted trees each with four taxa) is a convenient and statistically powerful technique to address this challenging problem. This approach was shown to be useful in several studies of completely sequenced microbial genomes. Results We present here a web server that takes a collection of gene phylogenies, decomposes them into quartets, generates a Quartet Spectrum, and draws a split network. Users are also provided with various data download options for further analyses. Each gene phylogeny is to be represented by an assessment of phylogenetic information content, such as sets of trees reconstructed from bootstrap replicates or sampled from a posterior distribution. The Quartet Decomposition server is accessible at http://quartets.uga.edu. Conclusions The Quartet Decomposition server presented here provides a convenient means to perform Quartet Decomposition analyses and will empower users to find statistically supported phylogenetic conflicts.
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Affiliation(s)
- Fenglou Mao
- Department of Biochemistry and Molecular Biology, University of Georgia, 120 Green St, Athens, GA 30622, USA
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45
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Roger F, Marchandin H, Jumas-Bilak E, Kodjo A, Lamy B. Multilocus genetics to reconstruct aeromonad evolution. BMC Microbiol 2012; 12:62. [PMID: 22545815 PMCID: PMC3487998 DOI: 10.1186/1471-2180-12-62] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Accepted: 04/30/2012] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Aeromonas spp. are versatile bacteria that exhibit a wide variety of lifestyles. In an attempt to improve the understanding of human aeromonosis, we investigated whether clinical isolates displayed specific characteristics in terms of genetic diversity, population structure and mode of evolution among Aeromonas spp. A collection of 195 Aeromonas isolates from human, animal and environmental sources was therefore genotyped using multilocus sequence analysis (MLSA) based on the dnaK, gltA, gyrB, radA, rpoB, tsf and zipA genes. RESULTS The MLSA showed a high level of genetic diversity among the population, and multilocus-based phylogenetic analysis (MLPA) revealed 3 major clades: the A. veronii, A. hydrophila and A. caviae clades, among the eleven clades detected. Lower genetic diversity was observed within the A. caviae clade as well as among clinical isolates compared to environmental isolates. Clonal complexes, each of which included a limited number of strains, mainly corresponded to host-associated subsclusters of strains, i.e., a fish-associated subset within A. salmonicida and 11 human-associated subsets, 9 of which included only disease-associated strains. The population structure was shown to be clonal, with modes of evolution that involved mutations in general and recombination events locally. Recombination was detected in 5 genes in the MLSA scheme and concerned approximately 50% of the STs. Therefore, these recombination events could explain the observed phylogenetic incongruities and low robustness. However, the MLPA globally confirmed the current systematics of the genus Aeromonas. CONCLUSIONS Evolution in the genus Aeromonas has resulted in exceptionally high genetic diversity. Emerging from this diversity, subsets of strains appeared to be host adapted and/or "disease specialized" while the A. caviae clade displayed an atypical tempo of evolution among aeromonads. Considering that A. salmonicida has been described as a genetically uniform pathogen that has adapted to fish through evolution from a variable ancestral population, we hypothesize that the population structure of aeromonads described herein suggested an ongoing process of adaptation to specialized niches associated with different degrees of advancement according to clades and clusters.
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Affiliation(s)
- Frédéric Roger
- Laboratoire de Bactériologie-Virologie, Université Montpellier, France
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Aujoulat F, Roger F, Bourdier A, Lotthé A, Lamy B, Marchandin H, Jumas-Bilak E. From environment to man: genome evolution and adaptation of human opportunistic bacterial pathogens. Genes (Basel) 2012; 3:191-232. [PMID: 24704914 PMCID: PMC3899952 DOI: 10.3390/genes3020191] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 02/29/2012] [Accepted: 02/29/2012] [Indexed: 02/07/2023] Open
Abstract
Environment is recognized as a huge reservoir for bacterial species and a source of human pathogens. Some environmental bacteria have an extraordinary range of activities that include promotion of plant growth or disease, breakdown of pollutants, production of original biomolecules, but also multidrug resistance and human pathogenicity. The versatility of bacterial life-style involves adaptation to various niches. Adaptation to both open environment and human specific niches is a major challenge that involves intermediate organisms allowing pre-adaptation to humans. The aim of this review is to analyze genomic features of environmental bacteria in order to explain their adaptation to human beings. The genera Pseudomonas, Aeromonas and Ochrobactrum provide valuable examples of opportunistic behavior associated to particular genomic structure and evolution. Particularly, we performed original genomic comparisons among aeromonads and between the strictly intracellular pathogens Brucella spp. and the mild opportunistic pathogens Ochrobactrum spp. We conclude that the adaptation to human could coincide with a speciation in action revealed by modifications in both genomic and population structures. This adaptation-driven speciation could be a major mechanism for the emergence of true pathogens besides the acquisition of specialized virulence factors.
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Affiliation(s)
- Fabien Aujoulat
- Université Montpellier 1, UMR 5119 (UM2, CNRS, IRD, IFREMER, UM1), équipe Pathogènes et Environnements, Montpellier 34093, France.
| | - Frédéric Roger
- Université Montpellier 1, UMR 5119 (UM2, CNRS, IRD, IFREMER, UM1), équipe Pathogènes et Environnements, Montpellier 34093, France.
| | - Alice Bourdier
- Université Montpellier 1, UMR 5119 (UM2, CNRS, IRD, IFREMER, UM1), équipe Pathogènes et Environnements, Montpellier 34093, France.
| | - Anne Lotthé
- Université Montpellier 1, UMR 5119 (UM2, CNRS, IRD, IFREMER, UM1), équipe Pathogènes et Environnements, Montpellier 34093, France.
| | - Brigitte Lamy
- Université Montpellier 1, UMR 5119 (UM2, CNRS, IRD, IFREMER, UM1), équipe Pathogènes et Environnements, Montpellier 34093, France.
| | - Hélène Marchandin
- Université Montpellier 1, UMR 5119 (UM2, CNRS, IRD, IFREMER, UM1), équipe Pathogènes et Environnements, Montpellier 34093, France.
| | - Estelle Jumas-Bilak
- Université Montpellier 1, UMR 5119 (UM2, CNRS, IRD, IFREMER, UM1), équipe Pathogènes et Environnements, Montpellier 34093, France.
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Williams D, Fournier GP, Lapierre P, Swithers KS, Green AG, Andam CP, Gogarten JP. A rooted net of life. Biol Direct 2011; 6:45. [PMID: 21936906 PMCID: PMC3189188 DOI: 10.1186/1745-6150-6-45] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 09/21/2011] [Indexed: 01/29/2023] Open
Abstract
Abstract Phylogenetic reconstruction using DNA and protein sequences has allowed the reconstruction of evolutionary histories encompassing all life. We present and discuss a means to incorporate much of this rich narrative into a single model that acknowledges the discrete evolutionary units that constitute the organism. Briefly, this Rooted Net of Life genome phylogeny is constructed around an initial, well resolved and rooted tree scaffold inferred from a supermatrix of combined ribosomal genes. Extant sampled ribosomes form the leaves of the tree scaffold. These leaves, but not necessarily the deeper parts of the scaffold, can be considered to represent a genome or pan-genome, and to be associated with members of other gene families within that sequenced (pan)genome. Unrooted phylogenies of gene families containing four or more members are reconstructed and superimposed over the scaffold. Initially, reticulations are formed where incongruities between topologies exist. Given sufficient evidence, edges may then be differentiated as those representing vertical lines of inheritance within lineages and those representing horizontal genetic transfers or endosymbioses between lineages. Reviewers W. Ford Doolittle, Eric Bapteste and Robert Beiko.
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Affiliation(s)
- David Williams
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269-3125, USA.
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Silver A, Graf J. Innate and procured immunity inside the digestive tract of the medicinal leech. INVERTEBRATE SURVIVAL JOURNAL : ISJ 2011; 8:173-178. [PMID: 22461860 PMCID: PMC3313596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Especially when combined with unique biological adaptations, invertebrate animals provide important insights into innate immunity because the immune response is not complicated by adaptive immunity that vertebrates evolved. One such example is the digestive tract of the medicinal leech, Hirudo verbana, which is unusual in two aspects, it contains a simple microbial community and it stores large amounts of vertebrate blood for a several months. In this review we will discuss aspects of the innate immunity of the leech and from the ingested blood that we term procured immunity to differentiate it from the immunity encoded by the leech genome.
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Affiliation(s)
- Ac Silver
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06520, USA
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Determination of microbial diversity of Aeromonas strains on the basis of multilocus sequence typing, phenotype, and presence of putative virulence genes. Appl Environ Microbiol 2011; 77:4986-5000. [PMID: 21642403 DOI: 10.1128/aem.00708-11] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The genus Aeromonas has been described as comprising several species associated with the aquatic environment, which represents their principal reservoir. Aeromonas spp. are commonly isolated from diseased and healthy fish, but the involvement of such bacteria in human infection and gastroenteritis has frequently been reported. The primary challenge in establishing an unequivocal link between the Aeromonas genus and pathogenesis in humans is the extremely complicated taxonomy. With the aim of clarifying taxonomic relationships among the strains and phenotypes, a multilocus sequencing approach was developed and applied to characterize 23 type and reference strains of Aeromonas spp. and a collection of 77 field strains isolated from fish, crustaceans, and mollusks. All strains were also screened for putative determinants of virulence by PCR (ast, ahh1, act, asa1, eno, ascV, and aexT) and the production of acylated homoserine lactones (AHLs). In addition, the phenotypic fingerprinting obtained from 29 biochemical tests was submitted to the nonparametric combination (NPC) test methodology to define the statistical differences among the identified genetic clusters. Multilocus sequence typing (MLST) achieved precise strain genotyping, and the phylogenetic analysis of concatenated sequences delineated the relationship among the taxa belonging to the genus Aeromonas, providing a powerful tool for outbreak traceability, host range diffusion, and ecological studies. The NPC test showed the feasibility of phenotypic differentiation among the majority of the MLST clusters by using a selection of tests or the entire biochemical fingerprinting. A Web-based MLST sequence database (http://pubmlst.org/aeromonas) specific for the Aeromonas genus was developed and implemented with all the results.
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