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Aggarwal D, Rajan D, Bellis KL, Betteridge E, Brennan J, de Sousa C, Parkhill J, Peacock SJ, de Goffau MC, Wagner J, Harrison EM. Optimization of high-throughput 16S rRNA gene amplicon sequencing: an assessment of PCR pooling, mastermix use and contamination. Microb Genom 2023; 9:001115. [PMID: 37843887 PMCID: PMC10634443 DOI: 10.1099/mgen.0.001115] [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: 08/01/2023] [Accepted: 09/28/2023] [Indexed: 10/17/2023] Open
Abstract
16S rRNA gene sequencing is widely used to characterize human and environmental microbiomes. Sequencing at scale facilitates better powered studies but is limited by cost and time. We identified two areas in our 16S rRNA gene library preparation protocol where modifications could provide efficiency gains, including (1) pooling of multiple PCR amplifications per sample to reduce PCR drift and (2) manual preparation of mastermix to reduce liquid handling. Using nasal samples from healthy human participants and a serially diluted mock microbial community, we compared alpha and beta diversity, and compositional abundance where the PCR amplification was conducted in triplicate, duplicate or as a single reaction, and where manually prepared or premixed mastermix was used. One hundred and fifty-eight 16S rRNA gene sequencing libraries were prepared, including a replicate experiment. Comparing PCR pooling strategies, we found no significant difference in high-quality read counts and alpha diversity, and beta diversity by Bray-Curtis index clustered by replicate on principal coordinate analysis (PCoA) and non-metric dimensional scaling (NMDS) analysis. Choice of mastermix had no significant impact on high-quality read and alpha diversity, and beta diversity by Bray-Curtis index clustered by replicate in PCoA and NMDS analysis. Importantly, we observed contamination and variability of rare species (<0.01 %) across replicate experiments; the majority of contaminants were accounted for by removal of species present at <0.1 %, or were linked to reagents (including a primer stock). We demonstrate no requirement for pooling of PCR amplifications or manual preparation of PCR mastermix, resulting in a more efficient 16S rRNA gene PCR protocol.
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Affiliation(s)
- Dinesh Aggarwal
- Department of Medicine, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - Diana Rajan
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - Katherine L. Bellis
- Department of Medicine, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | | | - Joe Brennan
- Department of Medicine, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - Catarina de Sousa
- Department of Medicine, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - CARRIAGE Study Team‡
- Department of Medicine, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
- Tytgat Institute for Liver and Intestinal Research, University of Amsterdam, Amsterdam, Netherlands
- Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - Julian Parkhill
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | | | - Marcus C. de Goffau
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
- Tytgat Institute for Liver and Intestinal Research, University of Amsterdam, Amsterdam, Netherlands
| | - Josef Wagner
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - Ewan M. Harrison
- Department of Medicine, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
- Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
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Harrison EM, Ba X, Coll F, Blane B, Restif O, Carvell H, Köser CU, Jamrozy D, Reuter S, Lovering A, Gleadall N, Bellis KL, Uhlemann AC, Lowy FD, Massey RC, Grilo IR, Sobral R, Larsen J, Rhod Larsen A, Vingsbo Lundberg C, Parkhill J, Paterson GK, Holden MTG, Peacock SJ, Holmes MA. Genomic identification of cryptic susceptibility to penicillins and β-lactamase inhibitors in methicillin-resistant Staphylococcus aureus. Nat Microbiol 2019; 4:1680-1691. [PMID: 31235959 PMCID: PMC7611363 DOI: 10.1038/s41564-019-0471-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 04/26/2019] [Indexed: 01/04/2023]
Abstract
Antibiotic resistance in bacterial pathogens threatens the future of modern medicine. One such resistant pathogen is methicillin-resistant Staphylococcus aureus (MRSA), which is resistant to nearly all β-lactam antibiotics, limiting treatment options. Here, we show that a significant proportion of MRSA isolates from different lineages, including the epidemic USA300 lineage, are susceptible to penicillins when used in combination with β-lactamase inhibitors such as clavulanic acid. Susceptibility is mediated by a combination of two different mutations in the mecA promoter region that lowers mecA-encoded penicillin-binding protein 2a (PBP2a) expression, and in the majority of isolates by either one of two substitutions in PBP2a (E246G or M122I) that increase the affinity of PBP2a for penicillin in the presence of clavulanic acid. Treatment of S. aureus infections in wax moth and mouse models shows that penicillin/β-lactamase inhibitor susceptibility can be exploited as an effective therapeutic choice for 'susceptible' MRSA infection. Finally, we show that isolates with the PBP2a E246G substitution have a growth advantage in the presence of penicillin but the absence of clavulanic acid, which suggests that penicillin/β-lactamase susceptibility is an example of collateral sensitivity (resistance to one antibiotic increases sensitivity to another). Our findings suggest that widely available and currently disregarded antibiotics could be effective in a significant proportion of MRSA infections.
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Affiliation(s)
- Ewan M Harrison
- Wellcome Sanger Institute, Hinxton, UK.
- Department of Medicine, University of Cambridge, Cambridge, UK.
- Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK.
| | - Xiaoliang Ba
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Francesc Coll
- London School of Hygiene and Tropical Medicine, London, UK
| | - Beth Blane
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Olivier Restif
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Henry Carvell
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Claudio U Köser
- Department of Genetics, University of Cambridge, Cambridge, UK
| | | | - Sandra Reuter
- Institute for Infection Prevention and Hospital Epidemiology, Medical Center - University of Freiburg, Freiburg, Germany
| | - Andrew Lovering
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | | | | | - Anne-Catrin Uhlemann
- Division of Infectious Diseases, Department of Medicine, Columbia University, New York, NY, USA
| | - Franklin D Lowy
- Division of Infectious Diseases, Department of Medicine, Columbia University, New York, NY, USA
| | - Ruth C Massey
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Inês R Grilo
- UCIBIO@REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Rita Sobral
- UCIBIO@REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Jesper Larsen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Anders Rhod Larsen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | | | | | - Gavin K Paterson
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
- The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | | | - Sharon J Peacock
- Wellcome Sanger Institute, Hinxton, UK
- Department of Medicine, University of Cambridge, Cambridge, UK
- London School of Hygiene and Tropical Medicine, London, UK
| | - Mark A Holmes
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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