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Armbruster CR, Hilliam YK, Zemke AC, Atteih S, Marshall CW, Moore J, Koirala J, Krainz L, Gaston JR, Lee SE, Cooper VS, Bomberger JM. Persistence and evolution of Pseudomonas aeruginosa following initiation of highly effective modulator therapy in cystic fibrosis. mBio 2024; 15:e0051924. [PMID: 38564694 PMCID: PMC11077959 DOI: 10.1128/mbio.00519-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 02/27/2024] [Indexed: 04/04/2024] Open
Abstract
Today, more than 90% of people with cystic fibrosis (pwCF) are eligible for the highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy called elexacaftor/tezacaftor/ivacaftor (ETI) and its use is widespread. Given the drastic respiratory symptom improvement experienced by many post-ETI, clinical studies are already underway to reduce the number of respiratory therapies, including antibiotic regimens, that pwCF historically relied on to combat lung disease progression. Early studies suggest that bacterial burden in the lungs is reduced post-ETI, yet it is unknown how chronic Pseudomonas aeruginosa populations are impacted by ETI. We found that pwCF remain infected throughout their upper and lower respiratory tract with their same strain of P. aeruginosa post-ETI, and these strains continue to evolve in response to the newly CFTR-corrected airway. Our work underscores the continued importance of CF airway microbiology in the new era of highly effective CFTR modulator therapy. IMPORTANCE The highly effective cystic fibrosis transmembrane conductance regulator modulator therapy Elexakaftor/Tezacaftor/Ivacaftor (ETI) has changed cystic fibrosis (CF) disease for many people with cystic fibrosis. While respiratory symptoms are improved by ETI, we found that people with CF remain infected with Pseudomonas aeruginosa. How these persistent and evolving bacterial populations will impact the clinical manifestations of CF in the coming years remains to be seen, but the role and potentially changing face of infection in CF should not be discounted in the era of highly effective modulator therapy.
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Affiliation(s)
- Catherine R. Armbruster
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Yasmin K. Hilliam
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Anna C. Zemke
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Samar Atteih
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | | | - John Moore
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Junu Koirala
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Leah Krainz
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jordan R. Gaston
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Stella E. Lee
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Vaughn S. Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
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2
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Nguyen JB, Marshall CW, Cook CN. The buzz within: the role of the gut microbiome in honeybee social behavior. J Exp Biol 2024; 227:jeb246400. [PMID: 38344873 DOI: 10.1242/jeb.246400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2024]
Abstract
Gut symbionts influence the physiology and behavior of their host, but the extent to which these effects scale to social behaviors is an emerging area of research. The use of the western honeybee (Apis mellifera) as a model enables researchers to investigate the gut microbiome and behavior at several levels of social organization. Insight into gut microbial effects at the societal level is critical for our understanding of how involved microbial symbionts are in host biology. In this Commentary, we discuss recent findings in honeybee gut microbiome research and synthesize these with knowledge of the physiology and behavior of other model organisms to hypothesize how host-microbe interactions at the individual level could shape societal dynamics and evolution.
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Affiliation(s)
- J B Nguyen
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - C W Marshall
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - C N Cook
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
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3
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Maghboli Balasjin N, Maki JS, Schläppi MR, Marshall CW. Plant Growth-Promoting Activity of Bacteria Isolated from Asian Rice (Oryza sativa L.) Depends on Rice Genotype. Microbiol Spectr 2022; 10:e0278721. [PMID: 35862989 PMCID: PMC9431195 DOI: 10.1128/spectrum.02787-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 06/16/2022] [Indexed: 11/24/2022] Open
Abstract
Asian rice is one of the most important crops because it is a staple food for almost half of the world's population. To have production of rice keep pace with a growing world population, it is anticipated that the use of fertilizers will also need to increase, which may cause environmental damage through runoff impacts. An alternative strategy to increase crop yield is the use of plant growth-promoting bacteria. Thousands of microbial species can exist in association with plant roots and shoots, and some are critical to the plant's survival. We isolated 140 bacteria from two distantly related rice accessions and investigated whether their impact on the growth of four different rice accessions. The bacterial isolates were screened for their ability to solubilize phosphate, a known plant growth-promoting characteristic, and 25 isolates were selected for further analysis. These 25 phosphate-solubilizing isolates were also able to produce other potentially growth-promoting factors. Five of the most promising bacterial isolates were chosen for whole-genome sequencing. Four of these bacteria, isolates related to Pseudomonas mosselii, a Microvirga sp., Paenibacillus rigui, and Paenibacillus graminis, improved root and shoot growth in a rice genotype-dependent manner. This indicates that while bacteria have several known plant growth-promoting functions, their effects on growth parameters are rice genotype dependent and suggest a close relationship between plants and their microbial partners. IMPORTANCE In this study, endophytic bacterial isolates from roots and shoots of two distantly related rice accessions were characterized phenotypically and genotypically. From the isolated bacterial species, five of the most promising plant growth-promoting bacteria were selected to test their abilities to enhance growth of the four rice accessions. Interestingly, plant growth enhancement was both bacterial isolate specific and plant genotype specific. However, the positive interactions between plant and bacteria could not easily be predicted because rice growth-promoting bacteria isolated from their host plants did not necessarily stimulate growth of their own host.
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Affiliation(s)
| | - James S. Maki
- Marquette University, Biological Sciences Department, Milwaukee, Wisconsin, USA
| | - Michael R. Schläppi
- Marquette University, Biological Sciences Department, Milwaukee, Wisconsin, USA
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4
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Grabowski S, Apolinario EA, Schneider NO, Marshall CW, Sowers K. Dethiosulfovibrio faecalis sp. nov., a novel proteolytic, non-sulphur-reducing bacterium isolated from a marine aquaculture solid waste bioreactor. Int J Syst Evol Microbiol 2022; 72. [DOI: 10.1099/ijsem.0.005456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A new
Dethiosulfovibrio
strain, designated F2BT, was isolated from an anaerobic digester for treating solid waste from a marine recirculating aquaculture system. The motile, Gram-negative, non-spore-forming curved rods were 2–7 µm long and 1 µm in diameter. Growth occurred at temperatures ranging from 20 to 40 °C with a maximum rate of growth at 30 °C. The pH range for growth was pH 6.0–8.0, with a maximum rate of growth at pH 7.5. This isolate was halotolerant growing in NaCl concentrations ranging from 0 to 1.6 M with a maximum rate of growth at 0.4 M. Similarly to the five described
Dethiosulfovibrio
species, this obligate anaerobe isolate was fermentative, capable of utilizing peptides, amino acids and some organic acids for growth, but unlike described strains in the genus did not reduce thiosulphate or elemental sulphur to hydrogen sulphide during fermentation of organic substrates. The G+C content of 55 mol% is similar to the described
Dethiosulfovibrio
species. The average nucleotide identity analysis between whole genome sequences showed less than 93.15% sequence similarity between strain F2BT and the five other described
Dethiosulfovibrio
species. Differences in the physiological and phylogenetic characteristics between the new strain and other
Dethiosulfovibrio
specied indicate that F2BT represents a novel species of this genus and the epithet Dethiosulfovibrio faecalis sp. nov. is proposed. The type strain is F2BT (=DSM 112078T=KCTC25378T).
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Affiliation(s)
- Stephen Grabowski
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, Maryland 21202, USA
| | - Ethel A. Apolinario
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, Maryland 21202, USA
| | - Nicholas O. Schneider
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, USA
| | | | - Kevin Sowers
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, Maryland 21202, USA
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Huo W, Busch LM, Hernandez-Bird J, Hamami E, Marshall CW, Geisinger E, Cooper VS, van Opijnen T, Rosch JW, Isberg RR. Immunosuppression broadens evolutionary pathways to drug resistance and treatment failure during Acinetobacter baumannii pneumonia in mice. Nat Microbiol 2022; 7:796-809. [PMID: 35618774 PMCID: PMC9159950 DOI: 10.1038/s41564-022-01126-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 04/20/2022] [Indexed: 01/02/2023]
Abstract
Acinetobacter baumannii is increasingly refractory to antibiotic treatment in healthcare settings. As is true of most human pathogens, the genetic path to antimicrobial resistance (AMR) and the role that the immune system plays in modulating AMR during disease are poorly understood. Here we reproduced several routes to fluoroquinolone resistance, performing evolution experiments using sequential lung infections in mice that are replete with or depleted of neutrophils, providing two key insights into the evolution of drug resistance. First, neutropenic hosts acted as reservoirs for the accumulation of drug resistance during drug treatment. Selection for variants with altered drug sensitivity profiles arose readily in the absence of neutrophils, while immunocompetent animals restricted the appearance of these variants. Secondly, antibiotic treatment failure in the immunocompromised host was shown to occur without clinically defined resistance, an unexpected result that provides a model for how antibiotic failure occurs clinically in the absence of AMR. The genetic mechanism underlying both these results is initiated by mutations activating the drug egress pump regulator AdeL, which drives persistence in the presence of antibiotic. Therefore, antibiotic persistence mutations present a two-pronged risk during disease, causing drug treatment failure in the immunocompromised host while simultaneously increasing the emergence of high-level AMR.
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Affiliation(s)
- Wenwen Huo
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - Lindsay M Busch
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
- Division of Infectious Diseases, Emory University School of Medicine, Atlanta, GA, USA
| | - Juan Hernandez-Bird
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - Efrat Hamami
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - Christopher W Marshall
- Department of Microbiology and Molecular Genetics and Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
| | | | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics and Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | - Jason W Rosch
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Ralph R Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
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6
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Santos-Lopez A, Fritz MJ, Lombardo JB, Burr AHP, Heinrich VA, Marshall CW, Cooper VS. Evolved resistance to a novel cationic peptide antibiotic requires high mutation supply. Evol Med Public Health 2022; 10:266-276. [PMID: 35712084 PMCID: PMC9198447 DOI: 10.1093/emph/eoac022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 05/21/2022] [Indexed: 01/30/2023] Open
Abstract
Background and Objectives A key strategy for resolving the antibiotic resistance crisis is the development of new drugs with antimicrobial properties. The engineered cationic antimicrobial peptide WLBU2 (also known as PLG0206) is a promising broad-spectrum antimicrobial compound that has completed Phase I clinical studies. It has activity against Gram-negative and Gram-positive bacteria including infections associated with biofilm. No definitive mechanisms of resistance to WLBU2 have been identified. Methodology Here, we used experimental evolution under different levels of mutation supply and whole genome sequencing (WGS) to detect the genetic pathways and probable mechanisms of resistance to this peptide. We propagated populations of wild-type and hypermutator Pseudomonas aeruginosa in the presence of WLBU2 and performed WGS of evolved populations and clones. Results Populations that survived WLBU2 treatment acquired a minimum of two mutations, making the acquisition of resistance more difficult than for most antibiotics, which can be tolerated by mutation of a single target. Major targets of resistance to WLBU2 included the orfN and pmrB genes, previously described to confer resistance to other cationic peptides. More surprisingly, mutations that increase aggregation such as the wsp pathway were also selected despite the ability of WLBU2 to kill cells growing in a biofilm. Conclusions and implications The results show how experimental evolution and WGS can identify genetic targets and actions of new antimicrobial compounds and predict pathways to resistance of new antibiotics in clinical practice.
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Affiliation(s)
- Alfonso Santos-Lopez
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, 15219 USA
- Present address: Department of Microbiology, Hospital Universitario Ramon y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Present address: Department of Microbial Biology, National Center of Biotechnology (CNB), Madrid, Spain
| | - Melissa J Fritz
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, 15219 USA
| | - Jeffrey B Lombardo
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, 15219 USA
| | - Ansen H P Burr
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, 15219 USA
| | - Victoria A Heinrich
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, 15219 USA
| | - Christopher W Marshall
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, 15219 USA
- Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Present address: Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, 15219 USA
- Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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7
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Marshall CW, Kurs-Lasky M, McElheny CL, Bridwell S, Liu H, Shaikh N. Performance of Conventional Urine Culture Compared to 16S rRNA Gene Amplicon Sequencing in Children with Suspected Urinary Tract Infection. Microbiol Spectr 2021; 9:e0186121. [PMID: 34937185 PMCID: PMC8694219 DOI: 10.1128/spectrum.01861-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/01/2021] [Indexed: 11/20/2022] Open
Abstract
Because some organisms causing urinary tract infection (UTI) may be difficult to culture, examination of bacterial gene sequences in the urine may provide a more accurate view of bacteria present during a UTI. Our objective was to estimate how often access to 16S rRNA gene amplicon sequencing alters diagnosis and/or clinical management. The study was designed as a cross-sectional study of a convenience sample of children with suspected UTI. The setting was the emergency department or outpatient clinic at six pediatric centers. Participants included children 2 months to 10 years of age suspected of UTI. We categorized the results of urine culture as follows: "likely UTI" (≥100,000 CFU/ml of a single uropathogen), "possible UTI" (10,000 to 99,000 CFU/ml of a uropathogen or ≥100,000 CFU/ml of a single uropathogen plus other growth), and "unlikely UTI" (no growth or growth of nonuropathogens). Similarly, we categorized the results of 16S rRNA gene sequencing into the same three categories using the following criteria: likely UTI (≥90% relative abundance of a uropathogen), possible UTI (50 to 89% relative abundance of a uropathogen), and unlikely UTI (remainder of samples). The main study outcome was concordance between conventional culture results and 16S rRNA gene sequencing. Concordance between the two methods was high in children with likely and unlikely UTI by conventional culture (95% and 87%, respectively). In children with possible UTI according to conventional culture, 71% had a single uropathogen at a relative abundance of ≥90% according to 16S rRNA gene sequencing data. Concordance between conventional culture and 16S rRNA gene amplicon sequencing appears to be high. In children with equivocal culture results, 16S rRNA gene results may provide information that may help clarify the diagnosis. IMPORTANCE Concordance between conventional culture and 16S rRNA gene amplicon sequencing appears to be high. In children with equivocal culture results, 16S rRNA gene results may provide information that may help clarify the diagnosis.
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Affiliation(s)
| | - Marcia Kurs-Lasky
- University of Pittsburgh School of Medicine, Children’s Hospital of Pittsburgh, Division of General Academic Pediatrics, Pittsburgh, Pennsylvania, USA
| | - Christi L. McElheny
- University of Pittsburgh School of Medicine, Children’s Hospital of Pittsburgh, Division of General Academic Pediatrics, Pittsburgh, Pennsylvania, USA
| | - Sophia Bridwell
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Hui Liu
- University of Pittsburgh School of Medicine, Children’s Hospital of Pittsburgh, Division of General Academic Pediatrics, Pittsburgh, Pennsylvania, USA
| | - Nader Shaikh
- University of Pittsburgh School of Medicine, Children’s Hospital of Pittsburgh, Division of General Academic Pediatrics, Pittsburgh, Pennsylvania, USA
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8
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Armbruster CR, Marshall CW, Garber AI, Melvin JA, Zemke AC, Moore J, Zamora PF, Li K, Fritz IL, Manko CD, Weaver ML, Gaston JR, Morris A, Methé B, DePas WH, Lee SE, Cooper VS, Bomberger JM. Adaptation and genomic erosion in fragmented Pseudomonas aeruginosa populations in the sinuses of people with cystic fibrosis. Cell Rep 2021; 37:109829. [PMID: 34686349 PMCID: PMC8667756 DOI: 10.1016/j.celrep.2021.109829] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/09/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022] Open
Abstract
Pseudomonas aeruginosa notoriously adapts to the airways of people with cystic fibrosis (CF), yet how infection-site biogeography and associated evolutionary processes vary as lifelong infections progress remains unclear. Here we test the hypothesis that early adaptations promoting aggregation influence evolutionary-genetic trajectories by examining longitudinal P. aeruginosa from the sinuses of six adults with CF. Highly host-adapted lineages harbored mutator genotypes displaying signatures of early genome degradation associated with recent host restriction. Using an advanced imaging technique (MiPACT-HCR [microbial identification after passive clarity technique]), we find population structure tracks with genome degradation, with the most host-adapted, genome-degraded P. aeruginosa (the mutators) residing in small, sparse aggregates. We propose that following initial adaptive evolution in larger populations under strong selection for aggregation, P. aeruginosa persists in small, fragmented populations that experience stronger effects of genetic drift. These conditions enrich for mutators and promote degenerative genome evolution. Our findings underscore the importance of infection-site biogeography to pathogen evolution.
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Affiliation(s)
- Catherine R Armbruster
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | | | - Arkadiy I Garber
- Biodesign Center for Mechanisms of Evolution and School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Jeffrey A Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Anna C Zemke
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - John Moore
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Paula F Zamora
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Kelvin Li
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Ian L Fritz
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Christopher D Manko
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Madison L Weaver
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Jordan R Gaston
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Alison Morris
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Barbara Methé
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - William H DePas
- Department of Pediatrics, Children's Hospital of Pittsburgh and University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Stella E Lee
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA.
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA; Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA; Pittsburgh Center for Evolutionary Biology & Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
| | - Jennifer M Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
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9
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Santos-Lopez A, Marshall CW, Haas AL, Turner C, Rasero J, Cooper VS. The roles of history, chance, and natural selection in the evolution of antibiotic resistance. eLife 2021; 10:e70676. [PMID: 34431477 PMCID: PMC8412936 DOI: 10.7554/elife.70676] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/24/2021] [Indexed: 12/20/2022] Open
Abstract
History, chance, and selection are the fundamental factors that drive and constrain evolution. We designed evolution experiments to disentangle and quantify effects of these forces on the evolution of antibiotic resistance. Previously, we showed that selection of the pathogen Acinetobacter baumannii in both structured and unstructured environments containing the antibiotic ciprofloxacin produced distinct genotypes and phenotypes, with lower resistance in biofilms as well as collateral sensitivity to β-lactam drugs (Santos-Lopez et al., 2019). Here we study how this prior history influences subsequent evolution in new β-lactam antibiotics. Selection was imposed by increasing concentrations of ceftazidime and imipenem and chance differences arose as random mutations among replicate populations. The effects of history were reduced by increasingly strong selection in new drugs, but not erased, at times revealing important contingencies. A history of selection in structured environments constrained resistance to new drugs and led to frequent loss of resistance to the initial drug by genetic reversions and not compensatory mutations. This research demonstrates that despite strong selective pressures of antibiotics leading to genetic parallelism, history can etch potential vulnerabilities to orthogonal drugs.
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Affiliation(s)
- Alfonso Santos-Lopez
- Department of Microbiology and Molecular Genetics, School of Medicine, University of PittsburghPittsburghUnited States
| | - Christopher W Marshall
- Department of Microbiology and Molecular Genetics, School of Medicine, University of PittsburghPittsburghUnited States
| | - Allison L Haas
- Department of Microbiology and Molecular Genetics, School of Medicine, University of PittsburghPittsburghUnited States
| | - Caroline Turner
- Department of Microbiology and Molecular Genetics, School of Medicine, University of PittsburghPittsburghUnited States
| | - Javier Rasero
- Department of Psychology, Carnegie Mellon UniversityPittsburghUnited States
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, School of Medicine, University of PittsburghPittsburghUnited States
- Center for Evolutionary Biology and Medicine, University of PittsburghPittsburghUnited States
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10
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Marshall CW, Gloag ES, Lim C, Wozniak DJ, Cooper VS. Rampant prophage movement among transient competitors drives rapid adaptation during infection. Sci Adv 2021; 7:7/29/eabh1489. [PMID: 34272240 PMCID: PMC8284892 DOI: 10.1126/sciadv.abh1489] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/03/2021] [Indexed: 05/11/2023]
Abstract
Interactions between bacteria, their close competitors, and viral parasites are common in infections, but understanding of these eco-evolutionary dynamics is limited. Most examples of adaptations caused by phage lysogeny are through the acquisition of new genes. However, integrated prophages can also insert into functional genes and impart a fitness benefit by disrupting their expression, a process called active lysogeny. Here, we show that active lysogeny can fuel rapid, parallel adaptations in establishing a chronic infection. These recombination events repeatedly disrupted genes encoding global regulators, leading to increased cyclic di-GMP levels and elevated biofilm production. The implications of prophage-mediated adaptation are broad, as even transient members of microbial communities can alter the course of evolution and generate persistent phenotypes associated with poor clinical outcomes.
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Affiliation(s)
| | - Erin S Gloag
- Department of Microbial Infection and Immunity, Ohio State University, Columbus, OH, USA
| | - Christina Lim
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, Ohio State University, Columbus, OH, USA
- Department of Microbiology, Ohio State University, Columbus, OH, USA
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA.
- Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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11
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Abstract
The price for renewable electricity is rapidly decreasing, and the availability of such energy is expected to increase in the coming years. This is a welcomed outcome considering that mitigation of climate disruption due to the use of fossil carbon is reaching a critical stage. However, the economy will remain dependent on carbon-based chemicals and the problem of electricity storage persists. Therefore, the development of electrosynthetic processes that convert electricity and CO2 into chemicals and energy dense fuels, perhaps even food, would be desirable. Electrochemistry has been applied to the manufacture of many valuable products and at a large industrial scale, but it is difficult to produce multicarbon chemicals from CO2 by chemistry alone. Being that the biological world possesses expertise at the construction of C-C bonds, it is being examined in conjunction with electrochemistry to discover new ways of synthesizing chemicals from electricity and CO2. One approach is microbial electrosynthesis. This Account describes the development of a microbial electrosynthesis system by the authors. A biocathode consisting of a carbon-based electrode and a microbial community produced short chain fatty acids, primarily acetate. The device works by electrolysis of water, but microbes facilitate electron transfer from the cathode while reducing CO2 by the Wood-Ljungdahl pathway possessed by an Acetobacterium sp. While this acetogenic microorganism dominates the microbiome growing on the cathode surface, 13 total species of microbes overall were ecologically selected on the cathode and genomes for each have been assembled. The combined species may contribute to the stability of the microbiome, a common feature of naturally selected microbial communities. The microbial electrosynthesis system was demonstrated to operate continuously at a cathode for more than 2 years and could also be used with intermittent power, thus demonstrating the stability of the microbiome living at the cathode. In addition to the description of reactor design and startup procedures, the possible mechanisms of electron transfer are described in this Account. While mysteries remain to be solved, much evidence indicates that the microbiome may facilitate electron transfer by supplying catalyst(s) external to the bacterial cells and onto the cathode surface. This may be in the form of a hydrogen-producing catalyst that enhances hydrogen generation by an inert carbon-based electrode. Through the enrichment of the electrosynthetic microbiome along with several modifications in reactor design and operation, the productivity and efficiency were improved. In addition to the intrinsic value of the current products, coupling the process with a secondary stage might be used to produce more valuable products from the acetic acid stream such as lipids, biocrude oil, or higher value food supplements. Alternatively, additional work on the mechanism of electron transfer, reactor design/operation, and modification of the microbes through synthetic biology, particularly to enhance carbon efficiency into higher value chemicals, are the needed next steps to advance microbial electrosynthesis so that it may be used to transform renewable electrons and CO2 directly into products and help solve the problem of climate disruption.
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Affiliation(s)
- Edward V. LaBelle
- Department of Organismic & Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Christopher W. Marshall
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Harold D. May
- Department of Microbiology & Immunology, Hollings Marine Laboratory, Medical University of South Carolina, Charleston, South Carolina 29412, United States
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12
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Lopez SM, Martin JM, Johnson M, Kurs-Lasky M, Horne WT, Marshall CW, Cooper VS, Williams JV, Shaikh N. A method of processing nasopharyngeal swabs to enable multiple testing. Pediatr Res 2019; 86:651-654. [PMID: 31288247 PMCID: PMC6851467 DOI: 10.1038/s41390-019-0498-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/08/2019] [Accepted: 06/08/2019] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To develop a method to perform multiple tests on a single nasopharyngeal (NP) swab. METHODS We collected a NP swab on children aged 2-12 years with acute sinusitis and processed it for bacterial culture, viruses, cytokine expression, and 16S ribosomal RNA gene sequencing analysis. During the course of the study, we expand the scope of evaluation to include RNA-sequencing, which we accomplished by cutting the tip of the swab. RESULTS Of the 174 children enrolled, 126 (72.4%) had a positive bacterial culture and 121 (69.5%) tested positive for a virus. Cytokine measurement, as judged by adequate levels of a housekeeping enzyme (glyceraldehyde 3-phosphate dehydrogenase), appeared successful. From the samples used for 16S ribosomal sequencing we recovered, on average, 16,000 sequences per sample, accounting for a total of 2646 operational taxonomic units across all samples sequenced. Samples used for RNA-sequencing had a mean RNA integrity number of 6.0. Cutting the tip of the swab did not affect the recovery yield for viruses or bacteria, nor did it affect species richness in microbiome analysis. CONCLUSION We describe a minimally invasive sample collection protocol that allows for multiple diagnostic and research investigations in young children.
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Affiliation(s)
- Santiago M.C. Lopez
- Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Judith M. Martin
- Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Monika Johnson
- Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Marcia Kurs-Lasky
- Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - William T. Horne
- Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Christopher W Marshall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Vaughn S. Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - John V. Williams
- Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Nader Shaikh
- Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA.
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13
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Mustapha MM, Li B, Pacey MP, Mettus RT, McElheny CL, Marshall CW, Ernst RK, Cooper VS, Doi Y. Phylogenomics of colistin-susceptible and resistant XDR Acinetobacter baumannii. J Antimicrob Chemother 2019; 73:2952-2959. [PMID: 30124845 DOI: 10.1093/jac/dky290] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 06/25/2018] [Indexed: 12/26/2022] Open
Abstract
Background Acinetobacter baumannii is a healthcare-associated pathogen with high rates of carbapenem resistance. Colistin is now routinely used for treatment of infections by this pathogen. However, colistin use has been associated with development of resistance to this agent. Objectives To elucidate the phylogenomics of colistin-susceptible and -resistant A. baumannii strain pairs from a cohort of hospitalized patients at a tertiary medical centre in the USA. Methods WGS data from 21 pairs of colistin-susceptible and -resistant, XDR clinical strains were obtained and compared using phylogeny of aligned genome sequences, assessment of pairwise SNP differences and gene content. Results Fourteen patients had colistin-resistant strains that were highly genetically related to their own original susceptible strain with a median pairwise SNP distance of 5.5 (range 1-40 SNPs), while seven other strain pairs were divergent with ≥84 SNP differences. In addition, several strains from different patients formed distinct clusters on the phylogeny in keeping with closely linked transmission chains. The majority of colistin-resistant strains contained non-synonymous mutations within the pmrAB locus suggesting a central role for pmrAB mutations in colistin resistance. Excellent genotype-phenotype correlation was also observed for carbapenems, aminoglycosides and tetracyclines. Conclusions The findings suggest that colistin resistance in the clinical setting arises through both in vivo evolution from colistin-susceptible strains and reinfection by unrelated colistin-resistant strains, the latter of which may involve patient-to-patient transmission.
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Affiliation(s)
- Mustapha M Mustapha
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Center for Innovative Antimicrobial Therapy, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Bin Li
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fuzhou, China
| | - Marissa P Pacey
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Roberta T Mettus
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Christi L McElheny
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Christopher W Marshall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Vaughn S Cooper
- Center for Innovative Antimicrobial Therapy, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Yohei Doi
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Center for Innovative Antimicrobial Therapy, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Microbiology, Fujita Health University, Aichi, Japan
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14
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Santos-Lopez A, Marshall CW, Scribner MR, Snyder DJ, Cooper VS. Evolutionary pathways to antibiotic resistance are dependent upon environmental structure and bacterial lifestyle. eLife 2019; 8:47612. [PMID: 31516122 PMCID: PMC6814407 DOI: 10.7554/elife.47612] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/13/2019] [Indexed: 12/11/2022] Open
Abstract
Bacterial populations vary in their stress tolerance and population structure depending upon whether growth occurs in well-mixed or structured environments. We hypothesized that evolution in biofilms would generate greater genetic diversity than well-mixed environments and lead to different pathways of antibiotic resistance. We used experimental evolution and whole genome sequencing to test how the biofilm lifestyle influenced the rate, genetic mechanisms, and pleiotropic effects of resistance to ciprofloxacin in Acinetobacter baumannii populations. Both evolutionary dynamics and the identities of mutations differed between lifestyle. Planktonic populations experienced selective sweeps of mutations including the primary topoisomerase drug targets, whereas biofilm-adapted populations acquired mutations in regulators of efflux pumps. An overall trade-off between fitness and resistance level emerged, wherein biofilm-adapted clones were less resistant than planktonic but more fit in the absence of drug. However, biofilm populations developed collateral sensitivity to cephalosporins, demonstrating the clinical relevance of lifestyle on the evolution of resistance. A bacterium known as Acinetobacter baumannii causes serious lung infections in people with weakened immune systems. These illnesses are becoming more common largely because A. baumannii is increasingly developing resistance to antibiotics. Inside the airways, individual A. baumannii cells can stick together and coat themselves in a slimy substance to form a structure called biofilm, which physically protects bacteria from antibiotics. This may be one of the reasons why it is often harder to treat bacterial infections associated with biofilms. Another possibility is that bacteria may evolve differently in biofilms compared with cells living independently. For example, A. baumannii may colonize several regions of the lungs during an infection, leading to distinct groups of bacteria that experience different conditions and evolve separately. Each population may therefore respond differently to an antibiotic. In contrast, bacteria living independently in a well-mixed population – such as in the bloodstream of their host – would be more likely to all evolve in the same way. Santos-Lopez, Marshall et al. tested this theory by exposing populations of A. baumannii that lived either independently or in biofilms to increasing levels of an antibiotic called ciprofloxacin. The genetic information of these cells was examined as the populations were evolving, and the bacteria were also put in contact with other types of antibiotics. The analyses revealed that bacteria in well-mixed populations shared the same limited number of mutations: these gave the bacteria high levels of resistance to the antibiotic’s primary target, an enzyme involved in DNA processes. The bacteria had also become resistant to other classes of antibiotics. In contrast, the bacteria in biofilm populations evolved to be more genetically diverse, exhibiting different types of mutations that helped the cells to pump out the drug. These bacteria were less resistant to ciprofloxacin and more sensitive to other types of antibiotics. Further experiments looked into the fitness of the bacteria – their ability to survive, reproduce and compete with each other. High levels of antibiotic resistance came with lower fitness: biofilm bacteria had evolved to become being fitter than those from well-mixed population. Even in the absence of drugs, these populations were in fact fitter than the original cells. Overall, understanding how the lifestyles of bacteria affect the way they respond to drugs may help researchers to develop new approaches that limit the spread of antibiotic resistance and improve treatment.
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Affiliation(s)
- Alfonso Santos-Lopez
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States
| | - Christopher W Marshall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States
| | - Michelle R Scribner
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States
| | - Daniel J Snyder
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States.,Microbial Genome Sequencing Center, University of Pittsburgh, Pittsburgh, United States
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States.,Microbial Genome Sequencing Center, University of Pittsburgh, Pittsburgh, United States
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15
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Gloag ES, Marshall CW, Snyder D, Lewin GR, Harris JS, Santos-Lopez A, Chaney SB, Whiteley M, Cooper VS, Wozniak DJ. Pseudomonas aeruginosa Interstrain Dynamics and Selection of Hyperbiofilm Mutants during a Chronic Infection. mBio 2019; 10:e01698-19. [PMID: 31409682 PMCID: PMC6692513 DOI: 10.1128/mbio.01698-19] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 07/10/2019] [Indexed: 12/14/2022] Open
Abstract
Opportunistic pathogens establishing new infections experience strong selection to adapt, often favoring mutants that persist. Capturing this initial dynamic is critical for identifying the first adaptations that drive pathogenesis. Here we used a porcine full-thickness burn wound model of chronic infection to study the evolutionary dynamics of diverse Pseudomonas aeruginosa infections. Wounds were infected with a mixed community of six P. aeruginosa strains, including the model PA14 strain (PA14-1), and biopsies taken at 3, 14, and 28 days postinfection. Hyperbiofilm-forming rugose small-colony variants (RSCVs) were the earliest and predominant phenotypic variant. These variants were detected on day 3 and persisted, with the majority evolved from PA14-1. Whole-genome sequencing of PA14-1 RSCV isolates revealed driver mutations exclusively in the wsp pathway, conferring hyperbiofilm phenotypes. Several of the wsp mutant RSCVs also acquired CRISPR-Cas adaptive immunity to prophages isolated from the P. aeruginosa wound isolate (B23-2) that was also present in the inoculum. These observations emphasize the importance of interstrain dynamics and the role of lysogenic phages in the survival of an invading pathogen. Rather than being a side effect of chronicity, the rapid rise of RSCVs in wounds is evidence of positive selection on the Wsp chemosensory system to produce mutants with elevated biofilm formation capacity. We predict that RSCVs provide a level of phenotypic diversity to the infecting bacterial community and are common, early adaptations during infections. This would likely have significant consequences for clinical outcomes.IMPORTANCE Bacteria adapt to infections by evolving variants that are more fit and persistent. These recalcitrant variants are typically observed in chronic infections. However, it is unclear when and why these variants evolve. To address these questions, we used a porcine chronic wound model to study the evolutionary dynamics of Pseudomonas aeruginosa in a mixed-strain infection. We isolated hyperbiofilm variants that persisted early in the infection. Interstrain interactions were also observed, where adapted variants acquired CRISPR-mediated immunity to phages. We show that when initiating infection, P. aeruginosa experiences strong positive selection for hyperbiofilm phenotypes produced by mutants of a single chemosensory system, the Wsp pathway. We predict that hyperbiofilm variants are early adaptations to infection and that interstrain interactions may influence bacterial burden and infection outcomes.
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Affiliation(s)
- Erin S Gloag
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA
| | - Christopher W Marshall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Daniel Snyder
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Gina R Lewin
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Emory-Children's Cystic Fibrosis Center, Atlanta, Georgia, USA
| | - Jacob S Harris
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA
| | - Alfonso Santos-Lopez
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarah B Chaney
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA
| | - Marvin Whiteley
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Emory-Children's Cystic Fibrosis Center, Atlanta, Georgia, USA
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
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16
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Payne RB, Ghosh U, May HD, Marshall CW, Sowers KR. Response to "Comment on 'A Pilot-Scale Field Study: In Situ Treatment of PCB-Impacted Sediments with Bioamended Activated Carbon'". Environ Sci Technol 2019; 53:6104-6105. [PMID: 31042364 DOI: 10.1021/acs.est.9b02107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Rayford B Payne
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology , University of Maryland Baltimore County , Baltimore , Maryland 21202 , United States
| | - Upal Ghosh
- Department of Chemical, Biochemical, and Environmental Engineering , University of Maryland Baltimore County , Baltimore , Maryland 21250 , United States
| | - Harold D May
- Hollings Marine Laboratory, Department of Microbiology and Immunology , Medical University of South Carolina , Charleston , South Carolina 29412 , United States
| | - Christopher W Marshall
- Biosciences Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Kevin R Sowers
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology , University of Maryland Baltimore County , Baltimore , Maryland 21202 , United States
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17
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Payne RB, Ghosh U, May HD, Marshall CW, Sowers KR. A Pilot-Scale Field Study: In Situ Treatment of PCB-Impacted Sediments with Bioamended Activated Carbon. Environ Sci Technol 2019; 53:2626-2634. [PMID: 30698958 DOI: 10.1021/acs.est.8b05019] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A combined approach involving microbial bioaugmentation and enhanced sorption was demonstrated to be effective for in situ treatment of polychlorinated biphenyls (PCBs). A pilot study was conducted for 409 days on PCB impacted sediments in four 400 m2 plots located in a watershed drainage pond in Quantico, VA. Treatments with activated carbon (AC) agglomerate bioamended with PCB dechlorinating and oxidizing bacteria decreased the PCB concentration in the top 7.5 cm by up to 52% and the aqueous concentrations of tri- to nonachlorobiphenyl PCB congeners by as much as 95%. Coplanar congeners decreased by up to 80% in sediment and were undetectable in the porewater. There was no significant decrease in PCB concentrations in non-bioamended plots with or without AC. All homologue groups decreased in bioamended sediment and porewater, indicating that both anaerobic dechlorination and aerobic degradation occurred concurrently. The titer of the bioamendments based on quantitative PCR of functional marker genes decreased but were still detectable after 409 days, whereas indigenous microbial diversity was not significantly different between sites, time points, or depths, indicating that bioaugmentation and the addition of activated carbon did not significantly alter total microbial diversity. In situ treatment of PCBs using an AC agglomerate as a delivery system for bioamendments is particularly well-suited for environmentally sensitive sites where there is a need to reduce exposure of the aquatic food web to sediment-bound PCBs with minimal disruption to the environment.
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Affiliation(s)
- Rayford B Payne
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology , University of Maryland Baltimore County , Baltimore Maryland 21202 , United States
| | - Upal Ghosh
- Department of Chemical, Biochemical, and Environmental Engineering , University of Maryland Baltimore County , Baltimore Maryland 21250 , United States
| | - Harold D May
- Hollings Marine Laboratory, Department of Microbiology and Immunology , Medical University of South Carolina , Charleston South Carolina 29412 , United States
| | - Christopher W Marshall
- Biosciences Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Kevin R Sowers
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology , University of Maryland Baltimore County , Baltimore Maryland 21202 , United States
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18
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Dunlap DG, Marshall CW, Fitch A, Rapport SF, Cooper VS, McVerry BJ, Morris A, Kitsios GD. Improved Detection of Culprit Pathogens by Bacterial DNA Sequencing Affects Antibiotic Management Decisions in Severe Pneumonia. Am J Case Rep 2018; 19:1405-1409. [PMID: 30473582 PMCID: PMC6280716 DOI: 10.12659/ajcr.912055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Patient: Male, 21 Final Diagnosis: Bacterial pneumonia Symptoms: Cough • fever Medication: — Clinical Procedure: — Specialty: Critical Care Medicine
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Affiliation(s)
- Daniel G Dunlap
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.,Center for Medicine and the Microbiome, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Christopher W Marshall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Adam Fitch
- Center for Medicine and the Microbiome, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Sarah F Rapport
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Bryan J McVerry
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.,Center for Medicine and the Microbiome, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Alison Morris
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.,Center for Medicine and the Microbiome, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.,Department of Immunology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Georgios D Kitsios
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.,Center for Medicine and the Microbiome, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
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19
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Turner CB, Marshall CW, Cooper VS. Parallel genetic adaptation across environments differing in mode of growth or resource availability. Evol Lett 2018; 2:355-367. [PMID: 30283687 PMCID: PMC6121802 DOI: 10.1002/evl3.75] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 06/18/2018] [Accepted: 07/06/2018] [Indexed: 01/13/2023] Open
Abstract
Evolution experiments have demonstrated high levels of genetic parallelism between populations evolving in identical environments. However, natural populations evolve in complex environments that can vary in many ways, likely sharing some characteristics but not others. Here, we ask whether shared selection pressures drive parallel evolution across distinct environments. We addressed this question in experimentally evolved populations founded from a clone of the bacterium Burkholderia cenocepacia. These populations evolved for 90 days (approximately 600 generations) under all combinations of high or low carbon availability and selection for either planktonic or biofilm modes of growth. Populations that evolved in environments with shared selection pressures (either level of carbon availability or mode of growth) were more genetically similar to each other than populations from environments that shared neither characteristic. However, not all shared selection pressures led to parallel evolution. Genetic parallelism between low-carbon biofilm and low-carbon planktonic populations was very low despite shared selection for growth under low-carbon conditions, suggesting that evolution in low-carbon environments may generate stronger trade-offs between biofilm and planktonic modes of growth. For all environments, a population's fitness in a particular environment was positively correlated with the genetic similarity between that population and the populations that evolved in that particular environment. Although genetic similarity was low between low-carbon environments, overall, evolution in similar environments led to higher levels of genetic parallelism and that genetic parallelism, in turn, was correlated with fitness in a particular environment.
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Affiliation(s)
- Caroline B. Turner
- Microbiology and Molecular GeneticsUniversity of PittsburghPittsburghPennsylvania
| | | | - Vaughn S. Cooper
- Microbiology and Molecular GeneticsUniversity of PittsburghPittsburghPennsylvania
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20
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Payne RB, Ghosh U, May HD, Marshall CW, Sowers KR. Mesocosm Studies on the Efficacy of Bioamended Activated Carbon for Treating PCB-Impacted Sediment. Environ Sci Technol 2017; 51:10691-10699. [PMID: 28809549 DOI: 10.1021/acs.est.7b01935] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This report describes results of a bench-scale treatability study to evaluate the efficacy of bioaugmentation with bioamended activated carbon (AC) for in situ treatment of polychlorinated biphenyl (PCB) impacted sediments. To this end, the ability of PCB transforming microorganisms to degrade and reduce the overall concentration of PCBs in sediment was determined in 2 L recirculating mesocosms designed to simulate conditions in Abraham's Creek in Quantico, Virginia. Ten sediment mesocosms were tested for the effects of AC alone, AC with slow release electron donor (cellulose) and different concentrations and combinations of PCB dehalogenating and degrading microorganisms added as bioamendments. A 78% reduction of total PCBs was observed using a cell titer of 5 × 105 Dehalobium chlorocoercia and Paraburkholderia xenovorans cells g-1 sediment with 1.5% AC as a delivery system. Levels of both higher and lower chlorinated congeners were reduced throughout the sediment column indicating that both anaerobic reductive dechlorination and aerobic degradation occurred concurrently. Porewater concentrations of all PCB homologues were reduced 94-97% for bioaugmented treatments. Toxicity associated with coplanar PCBs was reduced by 90% after treatment based on toxic equivalency of dioxin-like congeners. These results suggest that an in situ treatment employing the simultaneous application of anaerobic and aerobic microorganisms on AC could be an effective, environmentally sustainable strategy to reduce PCB levels in contaminated sediment.
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Affiliation(s)
- Rayford B Payne
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County , Baltimore, Maryland 21202, United States
| | - Upal Ghosh
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County , Baltimore, Maryland 21202, United States
| | - Harold D May
- Marine Biomedicine and Environmental Science Center, Department of Microbiology and Immunology, Medical University of South Carolina , Charleston, South Carolina 29425, United States
| | - Christopher W Marshall
- Biosciences Division, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Kevin R Sowers
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County , Baltimore, Maryland 21202, United States
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21
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Zhou GW, Yang XR, Marshall CW, Li H, Zheng BX, Yan Y, Su JQ, Zhu YG. Biochar Addition Increases the Rates of Dissimilatory Iron Reduction and Methanogenesis in Ferrihydrite Enrichments. Front Microbiol 2017; 8:589. [PMID: 28428774 PMCID: PMC5382251 DOI: 10.3389/fmicb.2017.00589] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/21/2017] [Indexed: 12/13/2022] Open
Abstract
Biochar contains quinones and aromatic structures that facilitate extracellular electron transfer between microbial cells and insoluble minerals. In this study, granulated biochar (1.2-2 mm) and powdered biochar (<0.15 mm) were amended to two ferrihydrite (in situ ferrihydrite and ex situ ferrihydrite) enrichments to investigate the effect of biochar with different particle sizes on dissimilatory iron(III)-reducing bacteria (DIRB) and methanogens. Biochar addition significantly stimulated the reduction of both in situ ferrihydrite and ex situ ferrihydrite and the production of methane. Powdered biochar amendments increased iron reduction compared to granulated biochar amendment in both the in situ ferrihydrite and ex situ ferrihydrite enrichments. However, no significant difference was observed in methane production between the powdered biochar and granulated biochar amendments in the two ferrihydrite enrichments. Analysis of 16S rRNA gene sequences showed that both DIRB and methanogens were enriched after biochar amendments in the in situ ferrihydrite and ex situ ferrihydrite enrichments. Taxa belonging to the Geobacteraceae and methanogenic genus affiliated to Methanosarcina were detected with significantly higher relative abundances in powdered biochar amendments than those in granulated biochar amendments in both the ferrihydrite enrichments. X-ray diffraction analysis indicated green rust [Fe2(CO3) (OH)] and vivianite [Fe3(PO4)2 8(H2O)] formed in the ex situ ferrihydrite and in situ ferrihydrite enrichments without biochar addition, respectively. After granulated biochar amendment, the mineral phase changed from the green rust to vivianite in the ex situ ferrihydrite enrichment, while crystalline vivianite and iron oxide (γ-Fe2O3) were detected simultaneously in the in situ ferrihydrite enrichment. No crystalline iron compound was found in the powdered biochar amendments in both ferrihydrite enrichments. Overall, our study illustrated that the addition of biochar affected iron-reducing and methane-generating microbial communities to some extent.
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Affiliation(s)
- Guo-Wei Zhou
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of SciencesXiamen, China
- University of Chinese Academy of SciencesBeijing, China
| | - Xiao-Ru Yang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of SciencesXiamen, China
| | - Christopher W. Marshall
- Department of Surgery, University of ChicagoChicago, IL, USA
- Biosciences Division, Argonne National LaboratoryLemont, IL, USA
| | - Hu Li
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of SciencesXiamen, China
| | - Bang-Xiao Zheng
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of SciencesXiamen, China
- University of Chinese Academy of SciencesBeijing, China
| | - Yu Yan
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of SciencesXiamen, China
- University of Chinese Academy of SciencesBeijing, China
| | - Jian-Qiang Su
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of SciencesXiamen, China
| | - Yong-Guan Zhu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of SciencesXiamen, China
- State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of SciencesBeijing, China
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Zhou GW, Yang XR, Li H, Marshall CW, Zheng BX, Yan Y, Su JQ, Zhu YG. Electron Shuttles Enhance Anaerobic Ammonium Oxidation Coupled to Iron(III) Reduction. Environ Sci Technol 2016; 50:9298-9307. [PMID: 27494694 DOI: 10.1021/acs.est.6b02077] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Anaerobic ammonium oxidation coupled to iron(III) reduction, termed Feammox, is a newly discovered nitrogen cycling process. However, little is known about the roles of electron shuttles in the Feammox reactions. In this study, two forms of Fe(III) (oxyhydr)oxide ferrihydrite (ex situ ferrihydrite and in situ ferrihydrite) were used in dissimilatory Fe(III) reduction (DIR) enrichments from paddy soil. Evidence for Feammox in DIR enrichments was demonstrated using the (15)N-isotope tracing technique. The extent and rate of both the (30)N2-(29)N2 and Fe(II) formation were enhanced when amended with electron shuttles (either 9,10-anthraquinone-2,6-disulfonate (AQDS) or biochar) and further simulated when these two shuttling compounds were combined. Although the Feammox-associated Fe(III) reduction accounted for only a minor proportion of total Fe(II) formation compared to DIR, it was estimated that the potentially Feammox-mediated N loss (0.13-0.48 mg N L(-1) day(-1)) was increased by 17-340% in the enrichments by the addition of electron shuttles. The addition of electron shuttles led to an increase in the abundance of unclassified Pelobacteraceae, Desulfovibrio, and denitrifiers but a decrease in Geobacter. Overall, we demonstrated a stimulatory effect of electron shuttles on Feammox that led to higher N loss, suggesting that electron shuttles might play a crucial role in Feammox-mediated N loss from soils.
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Affiliation(s)
- Guo-Wei Zhou
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, People's Republic of China
- University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Xiao-Ru Yang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, People's Republic of China
| | - Hu Li
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, People's Republic of China
- University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Christopher W Marshall
- Department of Surgery, University of Chicago , Chicago Illinois 60637, United States
- Biosciences Division, Argonne National Laboratory , 9700 South Cass Avenue Lemont, Illinois 60439, United States
| | - Bang-Xiao Zheng
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, People's Republic of China
- University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Yu Yan
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, People's Republic of China
- University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Jian-Qiang Su
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, People's Republic of China
| | - Yong-Guan Zhu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, People's Republic of China
- State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, People's Republic of China
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Ross DE, Marshall CW, May HD, Norman RS. Comparative Genomic Analysis of Sulfurospirillum cavolei MES Reconstructed from the Metagenome of an Electrosynthetic Microbiome. PLoS One 2016; 11:e0151214. [PMID: 26983005 PMCID: PMC4794192 DOI: 10.1371/journal.pone.0151214] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 02/23/2016] [Indexed: 11/19/2022] Open
Abstract
Sulfurospirillum spp. play an important role in sulfur and nitrogen cycling, and contain metabolic versatility that enables reduction of a wide range of electron acceptors, including thiosulfate, tetrathionate, polysulfide, nitrate, and nitrite. Here we describe the assembly of a Sulfurospirillum genome obtained from the metagenome of an electrosynthetic microbiome. The ubiquity and persistence of this organism in microbial electrosynthesis systems suggest it plays an important role in reactor stability and performance. Understanding why this organism is present and elucidating its genetic repertoire provide a genomic and ecological foundation for future studies where Sulfurospirillum are found, especially in electrode-associated communities. Metabolic comparisons and in-depth analysis of unique genes revealed potential ecological niche-specific capabilities within the Sulfurospirillum genus. The functional similarities common to all genomes, i.e., core genome, and unique gene clusters found only in a single genome were identified. Based upon 16S rRNA gene phylogenetic analysis and average nucleotide identity, the Sulfurospirillum draft genome was found to be most closely related to Sulfurospirillum cavolei. Characterization of the draft genome described herein provides pathway-specific details of the metabolic significance of the newly described Sulfurospirillum cavolei MES and, importantly, yields insight to the ecology of the genus as a whole. Comparison of eleven sequenced Sulfurospirillum genomes revealed a total of 6246 gene clusters in the pan-genome. Of the total gene clusters, 18.5% were shared among all eleven genomes and 50% were unique to a single genome. While most Sulfurospirillum spp. reduce nitrate to ammonium, five of the eleven Sulfurospirillum strains encode for a nitrous oxide reductase (nos) cluster with an atypical nitrous-oxide reductase, suggesting a utility for this genus in reduction of the nitrous oxide, and as a potential sink for this potent greenhouse gas.
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Affiliation(s)
- Daniel E. Ross
- Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, United States of America
| | - Christopher W. Marshall
- Department of Microbiology & Immunology, Marine Biomedicine & Environmental Science Center, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Harold D. May
- Department of Microbiology & Immunology, Marine Biomedicine & Environmental Science Center, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - R. Sean Norman
- Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, United States of America
- * E-mail:
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Burgsdorf I, Slaby BM, Handley KM, Haber M, Blom J, Marshall CW, Gilbert JA, Hentschel U, Steindler L. Lifestyle evolution in cyanobacterial symbionts of sponges. mBio 2015; 6:e00391-15. [PMID: 26037118 PMCID: PMC4453008 DOI: 10.1128/mbio.00391-15] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/30/2015] [Indexed: 01/04/2023] Open
Abstract
UNLABELLED The "Candidatus Synechococcus spongiarum" group includes different clades of cyanobacteria with high 16S rRNA sequence identity (~99%) and is the most abundant and widespread cyanobacterial symbiont of marine sponges. The first draft genome of a "Ca. Synechococcus spongiarum" group member was recently published, providing evidence of genome reduction by loss of genes involved in several nonessential functions. However, "Ca. Synechococcus spongiarum" includes a variety of clades that may differ widely in genomic repertoire and consequently in physiology and symbiotic function. Here, we present three additional draft genomes of "Ca. Synechococcus spongiarum," each from a different clade. By comparing all four symbiont genomes to those of free-living cyanobacteria, we revealed general adaptations to life inside sponges and specific adaptations of each phylotype. Symbiont genomes shared about half of their total number of coding genes. Common traits of "Ca. Synechococcus spongiarum" members were a high abundance of DNA modification and recombination genes and a reduction in genes involved in inorganic ion transport and metabolism, cell wall biogenesis, and signal transduction mechanisms. Moreover, these symbionts were characterized by a reduced number of antioxidant enzymes and low-weight peptides of photosystem II compared to their free-living relatives. Variability within the "Ca. Synechococcus spongiarum" group was mostly related to immune system features, potential for siderophore-mediated iron transport, and dependency on methionine from external sources. The common absence of genes involved in synthesis of residues, typical of the O antigen of free-living Synechococcus species, suggests a novel mechanism utilized by these symbionts to avoid sponge predation and phage attack. IMPORTANCE While the Synechococcus/Prochlorococcus-type cyanobacteria are widely distributed in the world's oceans, a subgroup has established its niche within marine sponge tissues. Recently, the first genome of sponge-associated cyanobacteria, "Candidatus Synechococcus spongiarum," was described. The sequencing of three representatives of different clades within this cyanobacterial group has enabled us to investigate intraspecies diversity, as well as to give a more comprehensive understanding of the common symbiotic features that adapt "Ca. Synechococcus spongiarum" to its life within the sponge host.
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Affiliation(s)
- Ilia Burgsdorf
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Beate M Slaby
- Department of Botany II, Julius-von-Sachs Institute for Biosciences, University of Würzburg, Würzburg, Germany
| | - Kim M Handley
- Department of Ecology and Evolution, The University of Chicago, Chicago, Illinois, USA
| | - Markus Haber
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Jochen Blom
- Bioinformatics and System Biology Justus-Liebig-University, Giessen, Giessen, Germany
| | - Christopher W Marshall
- Argonne National Laboratory, Institute for Genomic and Systems Biology, Argonne, Illinois, USA
| | | | - Ute Hentschel
- Department of Botany II, Julius-von-Sachs Institute for Biosciences, University of Würzburg, Würzburg, Germany
| | - Laura Steindler
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
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LaBelle EV, Marshall CW, Gilbert JA, May HD. Influence of acidic pH on hydrogen and acetate production by an electrosynthetic microbiome. PLoS One 2014; 9:e109935. [PMID: 25333313 PMCID: PMC4198145 DOI: 10.1371/journal.pone.0109935] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 09/09/2014] [Indexed: 12/02/2022] Open
Abstract
Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (∼5). Hydrogen production by biocathodes poised at −600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ∼5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ∼6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at −765 mV (0.065 mA/cm2 sterile control at −800 mV) by the Acetobacterium-dominated community. Supplying −800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (≈2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate ( = 4.7 kg CO2 captured).
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Affiliation(s)
- Edward V. LaBelle
- Department of Microbiology & Immunology, Marine Biomedicine & Environmental Science Center, Hollings Marine Laboratory, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Christopher W. Marshall
- Institute for Genomic and Systems Biology, Argonne National Laboratory, Argonne, Illinois, United States of America
| | - Jack A. Gilbert
- Institute for Genomic and Systems Biology, Argonne National Laboratory, Argonne, Illinois, United States of America
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
- Marine Biological Laboratory, Woods Hole, Massachusetts, United States of America
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Harold D. May
- Department of Microbiology & Immunology, Marine Biomedicine & Environmental Science Center, Hollings Marine Laboratory, Medical University of South Carolina, Charleston, South Carolina, United States of America
- * E-mail:
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Marshall CW, Ross DE, Fichot EB, Norman RS, May HD. Long-term operation of microbial electrosynthesis systems improves acetate production by autotrophic microbiomes. Environ Sci Technol 2013; 47:6023-9. [PMID: 23676111 DOI: 10.1021/es400341b] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Microbial electrosynthesis is the biocathode-driven production of chemicals from CO2 and has the promise to be a sustainable, carbon-consuming technology. To date, microbial electrosynthesis of acetate, the first step in order to generate liquid fuels from CO2, has been characterized by low rates and yields. To improve performance, a previously established acetogenic biocathode was operated in semi-batch mode at a poised potential of -590 mV vs SHE for over 150 days beyond its initial development. Rates of acetate production reached a maximum of 17.25 mM day(-1) (1.04 g L(-1) d(-1)) with accumulation to 175 mM (10.5 g L(-1)) over 20 days. Hydrogen was also produced at high rates by the biocathode, reaching 100 mM d(-1) (0.2 g L(-1) d(-1)) and a total accumulation of 1164 mM (2.4 g L(-1)) over 20 days. Phylogenetic analysis of the active electrosynthetic microbiome revealed a similar community structure to what was observed during an earlier stage of development of the electroacetogenic microbiome. Acetobacterium spp. dominated the active microbial population on the cathodes. Also prevalent were Sulfurospirillum spp. and an unclassified Rhodobacteraceae. Taken together, these results demonstrate the stability, resilience, and improved performance of electrosynthetic biocathodes following long-term operation. Furthermore, sustained product formation at faster rates by a carbon-capturing microbiome is a key milestone addressed in this study that advances microbial electrosynthesis systems toward commercialization.
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Affiliation(s)
- Christopher W Marshall
- Department of Microbiology & Immunology, Marine Biomedicine & Environmental Science Center, Medical University of South Carolina, Charleston, South Carolina 29425, United States
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Marshall CW, LaBelle EV, May HD. Production of fuels and chemicals from waste by microbiomes. Curr Opin Biotechnol 2013; 24:391-7. [PMID: 23587964 DOI: 10.1016/j.copbio.2013.03.016] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 03/01/2013] [Accepted: 03/19/2013] [Indexed: 10/26/2022]
Abstract
The demand for chemicals and fuels will continue to grow simultaneously with the costly requirement to treat solid waste, wastewater, and regarding climate change, carbon dioxide. A dual benefit is at hand if waste could be converted to valuable chemicals. The application of stable chemical producing microbiomes adapted to these waste streams may turn this challenge into an opportunity.
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Affiliation(s)
- Christopher W Marshall
- Department of Microbiology & Immunology, Marine Biomedicine & Environmental Science Center, Medical University of South Carolina, United States
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Abstract
Systems designed to recognize continuous speech must be able to adapt to many types of acoustic variation, including variations in stress. A speaker-dependent recognition study was conducted on a group of stressed and destressed syllables. These syllables, some containing the short vowel /I/ and others the long vowel /ae/, were excised from continuous speech and transformed into arrays of cepstral coefficients at two levels of precision. From these data, four types of template dictionaries varying in size and stress composition were formed by a time-warping procedure. Recognition performance data were gathered from listeners and from a computer recognition algorithm that also employed warping. It was found that for a significant portion of the data base, stressed and destressed versions of the same syllable are sufficiently different from one another as to justify the use of separate dictionary templates. Second, destressed syllables exhibit roughly the same acoustic variance as their stressed counterparts. Third, long vowels tend to be involved in proportionally fewer cross-vowel errors but tend to diminish the warping algorithm's ability to discriminate consonantal information. Finally, the pattern of consonant errors that listeners make as a function of vowel length shows significant differences from that produced by the computer.
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Abstract
By means of an articulatory synthesizer, the perception of the oral-nasal distinction in consonants was explored experimentally. This distinction was chosen because it is achieved by a very simple articulatory maneuver and because it is phonologically relevant in virtually every language. Lowering the velum in equal increments provided continua of CV syllables varying in size of velopharyngeal port which were divided perceptually into /d/ and /n/ categories by American English listeners. To test the hypothesis that the coarticulation of these nasal consonants with lower (more open) vowels requires a larger area of velopharyngeal coupling to give a nasal consonant precept, three oral-nasal continua incorporating the vowels /i/, /delta/, and /alpha/, respectively, were presented for identification. The results were compared with those of A. S. House and K. N. Stevens [J. Speech Hear. Disord. 21, 218-232 (1956)] and A. S. House [J. Speech Hear. Disord. 22, 190-204 (1957)] obtained with steady-state vowels and consonantal murmurs and with those of M. H. L. Hecker [J. Acoust. Soc. Am. 34, 179-188 (1962)]. Three conclusions emerged. First, the relationship between vowel height and the amount of velopharyngeal coupling needed for a nasal precept occurs in conditions where subjects are required to make linguistically relevant judgments. Second, the relationship can arise in conditions where vocalic coarticulation is present. Third, the relationship is not confined to vowels but can also be observed in the case of dynamically articulated consonants. One of the continua was also used for discrimination experiments, which yielded the classical pattern of high discriminability at the category boundary.
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