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Lee S, Choe J, Kang M, Kang M, Kim S, Oh S. Evaluating the Potential of Korean Mudflat-Derived Penicillium nalgiovense SJ02 as a Fungal Starter for Manufacturing Fermented Sausage. Food Sci Anim Resour 2024; 44:912-933. [PMID: 38974723 PMCID: PMC11222695 DOI: 10.5851/kosfa.2024.e30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 03/30/2024] [Accepted: 04/09/2024] [Indexed: 07/09/2024] Open
Abstract
The objective of this study was to isolate, identify, and evaluate novel Korean starter cultures for use in fermented sausages. A total of 72 strains were isolated from various indigenous sources, including Nuruk, Jeotgal, and mudflats on the west coast of South Korea. Two strains were identified as Penicillium nalgiovense (SD01 and SJ02), a traditional starter used in the production of fermented sausages. A comparative analysis was performed between SD01 and SJ02 using the commercial starter culture (M600). Strain SJ02 exhibited superior lipolytic and proteolytic activities, as well as an enhanced growth rate at the optimal salinity level of 2% NaCl compared to M600. No significant differences were observed in thiobarbituric acid reactive substances values, sausage colors, and texture properties between SJ02 and M600 fermented sausages, except for adhesiveness. Profiles of mycotoxin-related genes were similar for both strains. Electronic nose analysis revealed distinct aroma profiles between SJ02 and M600 fermented sausages, with a relatively higher levels of propan-2-one and butyl butanoate in SJ02, and a higher level of ethanol and propanal in M600. In electronic tongue analysis, there was no significant differences in taste characteristics between SJ02 and M600. These results indicate that P. nalgiovense SJ02 is a potential starter culture to produce dry fermented sausages, enhancing Korean style cured meat processing industry.
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Affiliation(s)
- Sujeong Lee
- Department of Food and Nutrition, Jeonju
University, Jeonju 55069, Korea
| | - Jeehwan Choe
- Department of Livestock, Korea National
University of Agriculture and Fisheries, Jeonju 54874,
Korea
| | - Minji Kang
- Department of Food and Nutrition, Jeonju
University, Jeonju 55069, Korea
| | - Minkyoung Kang
- Department of Food and Nutrition, Jeonju
University, Jeonju 55069, Korea
| | - Sooah Kim
- Department of Environment Science and
Biotechnology, Jeonju University, Jeonju 55069, Korea
| | - Sangnam Oh
- Department of Food and Nutrition, Jeonju
University, Jeonju 55069, Korea
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2
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Spreckels JE, Fernández-Pato A, Kruk M, Kurilshikov A, Garmaeva S, Sinha T, Ghosh H, Harmsen H, Fu J, Gacesa R, Zhernakova A. Analysis of microbial composition and sharing in low-biomass human milk samples: a comparison of DNA isolation and sequencing techniques. ISME COMMUNICATIONS 2023; 3:116. [PMID: 37945978 PMCID: PMC10636111 DOI: 10.1038/s43705-023-00325-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 10/18/2023] [Accepted: 10/26/2023] [Indexed: 11/12/2023]
Abstract
Human milk microbiome studies are currently hindered by low milk bacterial/human cell ratios and often rely on 16S rRNA gene sequencing, which limits downstream analyses. Here, we aimed to find a method to study milk bacteria and assess bacterial sharing between maternal and infant microbiota. We tested four DNA isolation methods, two bacterial enrichment methods and three sequencing methods on mock communities, milk samples and negative controls. Of the four DNA isolation kits, the DNeasy PowerSoil Pro (PS) and MagMAX Total Nucleic Acid Isolation (MX) kits provided consistent 16S rRNA gene sequencing results with low contamination. Neither enrichment method substantially decreased the human metagenomic sequencing read-depth. Long-read 16S-ITS-23S rRNA gene sequencing biased the mock community composition but provided consistent results for milk samples, with little contamination. In contrast to 16S rRNA gene sequencing, 16S-ITS-23S rRNA gene sequencing of milk, infant oral, infant faecal and maternal faecal DNA from 14 mother-infant pairs provided sufficient resolution to detect significantly more frequent sharing of bacteria between related pairs compared to unrelated pairs. In conclusion, PS or MX kit-DNA isolation followed by 16S rRNA gene sequencing reliably characterises human milk microbiota, and 16S-ITS-23S rRNA gene sequencing enables studies of bacterial transmission in low-biomass samples.
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Grants
- This study was supported by funds from the Dutch Research Council (NWO-VIDI grant 016.178.056 to A.Z., NWO-VICI grant VI.C.202.022 to J.F., NWO gravitation grant Exposome-NL 024.004.017 to A.K. and A.Z., NWO gravitation grant Netherlands Organ-on-Chip Initiative 024.003.001 to J.F.), the Dutch Heart Foundation (IN-CONTROL CVON2018-27 to J.F.), the European Research Council (ERC starting grant 715772 to A.Z., ERC consolidator grant 101001678 to J.F.), an EASI-Genomics grant (PID7780 to T.S. and A.Z.), the De-Cock Hadders foundation (2021-57 to J.E.S., 2021-08 to S.G.), the International Society for Research in Human Milk and Lactation (ISRHML, personal grant to J.E.S), the Winston Bakker Fonds (WB-08, granted to T.S.), and the European Union’s Horizon 2020 research innovation program (824110). S.G. and T.S. hold scholarships from the Graduate School of Medical Sciences and the Junior Scientific Masterclass of the University of Groningen, the Netherlands, respectively. The Lifelines NEXT cohort study received funds from the University Medical Center Groningen Hereditary Metabolic Diseases Fund, Health~Holland (Top Sector Life Sciences and Health), the Ubbo Emmius Foundation, the European Union, the Northern Netherlands Alliance (SNN), the provinces of Friesland and Groningen, the municipality of Groningen, Philips, and the Société des Produits Nestlé.
- De-Cock Hadders foundation (2021-57) International Society of Research in Human Milk and Lactation (ISRHML personal grant)
- Dutch Research Council (NWO gravitation grant Exposome-NL 024.004.017)
- De-Cock Hadders foundation (2021-08) University of Groningen Graduate School of Medical Sciences (scholarship)
- EASI-Genomics (grant PID7780) Winston Bakker Fonds (WB-08) University of Groningen Junior Scientific Masterclass (scholarship)
- Dutch Research Council (NWO-VICI grant VI.C.202.022) Dutch Research Council (NWO gravitation grant Netherlands Organ-on-Chip Initiative 024.003.001) European Research Council (ERC consolidator grant 101001678)
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Affiliation(s)
- Johanne E Spreckels
- Department of Genetics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Asier Fernández-Pato
- Department of Genetics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Marloes Kruk
- Department of Genetics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Alexander Kurilshikov
- Department of Genetics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Sanzhima Garmaeva
- Department of Genetics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Trishla Sinha
- Department of Genetics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Hiren Ghosh
- Medical Center - University of Freiburg, Institute for Infection Prevention and Hospital Epidemiology, Freiburg, Germany
| | - Hermie Harmsen
- Department of Medical Microbiology, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Jingyuan Fu
- Department of Genetics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
- Department of Pediatrics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Ranko Gacesa
- Department of Genetics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
- Department of Gastroenterology and Hepatology, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Alexandra Zhernakova
- Department of Genetics, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands.
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Kenger EB, Eren F, Ozlu T, Gunes FE. Analysis of microbiota profile and nutritional status in male professional football players. J Sports Med Phys Fitness 2023; 63:1235-1243. [PMID: 37486255 DOI: 10.23736/s0022-4707.23.15103-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
BACKGROUND The interest in the effect of gut microbiota on athlete health has increased in recent years. Available data indicate a relationship between gut microbiota composition and physical activity, suggesting that changes in the microbiota may contribute to the host's physical performance. Studies show that leaky gut syndrome is highly correlated with upper respiratory infections and gastrointestinal disorders in endurance sports. This study aims to reveal the relationship between microbiota profiles, and the nutritional status of football players who perform endurance exercises. METHODS Twenty male professional football players playing in one of the Turkish Football Federation Second League clubs participated in the study. Fecal samples were collected and stored at -86 °C, and the fecal microbiota was analyzed through 16s rRNA gene sequencing. The body composition of the football players was measured using a bioelectrical impedance analyzer. In addition, the 3-day food intake of the participants was recorded with the help of a dietitian. RESULTS In the microbiota of football players, four phyla, 10 genera, and four species with densities above 1% were found. Body fat percentage was observed to be negatively correlated with the species of Faecalibacterium prausnitzii and Bacteroides vulgatus and the genus of Faecalibacterium (P<0.05). Considering the nutritional status, the fat intake was found to be positively correlated with Actinobacteria and Blautia coccoides; energy and fiber intake with Prevotella and Prevotella copri (P<0.05). In addition, there was a negative correlation between carbohydrate intake and Faecalibacterium (P<0.05). CONCLUSIONS Our study is the first to reveal the microbiota profile of professional Turkish football players. It was found that football players' nutritional status and anthropometric measurements of are significantly related to phylum, genus and species ranks in the microbiota. These results support the bidirectional interaction between microbiota and sports. The relationship between microbiota and sports health/performance is thought to be further clarified with future studies.
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Affiliation(s)
- Emre B Kenger
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Bahcesehir University, Istanbul, Türkiye -
| | - Fatih Eren
- Institute of Gastroenterology, Marmara University, Istanbul, Türkiye
| | - Tugce Ozlu
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Bahcesehir University, Istanbul, Türkiye
| | - Fatma E Gunes
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Medeniyet University, Istanbul, Türkiye
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Alemán-Duarte MI, Aguilar-Uscanga BR, García-Robles G, Ramírez-Salazar FDJ, Benítez-García I, Balcázar-López E, Solís-Pacheco JR. Improvement and Validation of a Genomic DNA Extraction Method for Human Breastmilk. Methods Protoc 2023; 6:mps6020034. [PMID: 37104016 PMCID: PMC10144544 DOI: 10.3390/mps6020034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/08/2023] [Accepted: 03/09/2023] [Indexed: 03/29/2023] Open
Abstract
The human milk microbiota (HMM) of healthy women can vary substantially, as demonstrated by recent advances in DNA sequencing technology. However, the method used to extract genomic DNA (gDNA) from these samples may impact the observed variations and potentially bias the microbiological reconstruction. Therefore, it is important to use a DNA extraction method that is able to effectively isolate gDNA from a diverse range of microorganisms. In this study, we improved and compared a DNA extraction method for gDNA isolation from human milk (HM) samples to commercial and standard protocols. We evaluated the extracted gDNA using spectrophotometric measurements, gel electrophoresis, and PCR amplifications to assess its quantity, quality, and amplifiability. Additionally, we tested the improved method’s ability to isolate amplifiable gDNA from fungi, Gram-positive and Gram-negative bacteria to validate its potential for reconstructing microbiological profiles. The improved DNA extraction method resulted in a higher quality and quantity of the extracted gDNA compared to the commercial and standard protocols and allowed for polymerase chain reaction (PCR) amplification of the V3–V4 regions of the 16S ribosomal gene in all the samples and the ITS-1 region of the fungal 18S ribosomal gene in 95% of the samples. These results suggest that the improved DNA extraction method demonstrates better performance for gDNA extraction from complex samples such as HM.
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Affiliation(s)
- Mario Iván Alemán-Duarte
- Laboratorio de Microbiología Industrial, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Blvd, Gral, Marcelino García Barragán 1421, Olímpica, Guadalajara 44430, Mexico
| | - Blanca Rosa Aguilar-Uscanga
- Laboratorio de Microbiología Industrial, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Blvd, Gral, Marcelino García Barragán 1421, Olímpica, Guadalajara 44430, Mexico
| | - Guadalupe García-Robles
- Laboratorio de Microbiología Industrial, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Blvd, Gral, Marcelino García Barragán 1421, Olímpica, Guadalajara 44430, Mexico
| | - Felipe de Jesús Ramírez-Salazar
- Laboratorio de Microbiología Industrial, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Blvd, Gral, Marcelino García Barragán 1421, Olímpica, Guadalajara 44430, Mexico
| | - Israel Benítez-García
- Unidad Académica de Ingeniería en Biotecnología, Universidad Politécnica de Sinaloa (UPSIN), Carretera Municipal Libre Mazatlán Higueras Km 3 Col. Genaro Estrada, Mazatlán 82199, Mexico
| | - Edgar Balcázar-López
- Laboratorio de Microbiología Industrial, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Blvd, Gral, Marcelino García Barragán 1421, Olímpica, Guadalajara 44430, Mexico
- Correspondence: (E.B.-L.); (J.R.S.-P.); Tel.: +52-(33)-1378-59000 (ext. 27648) (J.R.S.-P.)
| | - Josué Raymundo Solís-Pacheco
- Laboratorio de Microbiología Industrial, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Blvd, Gral, Marcelino García Barragán 1421, Olímpica, Guadalajara 44430, Mexico
- Correspondence: (E.B.-L.); (J.R.S.-P.); Tel.: +52-(33)-1378-59000 (ext. 27648) (J.R.S.-P.)
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5
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Karolenko C, DeSilva U, Muriana PM. Microbial Profiling of Biltong Processing Using Culture-Dependent and Culture-Independent Microbiome Analysis. Foods 2023; 12:foods12040844. [PMID: 36832921 PMCID: PMC9957202 DOI: 10.3390/foods12040844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/14/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023] Open
Abstract
Biltong is a South African air-dried beef product that does not have a heat lethality step, but rather relies on marinade chemistry (low pH from vinegar, ~2% salt, spices/pepper) in combination with drying at ambient temperature and low humidity to achieve microbial reduction during processing. Culture-dependent and culture-independent microbiome methodologies were used to determine the changes in the microbial community at each step during biltong processing through 8 days of drying. Culture-dependent analysis was conducted using agar-based methods to recover viable bacteria from each step in the biltong process that were identified with 16S rRNA PCR, sequencing, and BLAST searching of the NCBI nucleotide database. DNA was extracted from samples taken from the laboratory meat processing environment, biltong marinade, and beef samples at three stages of processing (post-marinade, day 4, and day 8). In all, 87 samples collected from two biltong trials with beef obtained from each of three separate meat processors (n = six trials) were amplified, sequenced with Illumina HiSeq, and evaluated with bioinformatic analysis for a culture-independent approach. Both culture-dependent and independent methodologies show a more diverse population of bacteria present on the vacuum-packaged chilled raw beef that reduces in diversity during biltong processing. The main genera present after processing were identified as Latilactobacillus sp., Lactococcus sp., and Carnobacterium sp. The high prevalence of these organisms is consistent with extended cold-storage of vacuum-packaged beef (from packers, to wholesalers, to end users), growth of psychrotrophs at refrigeration temperatures (Latilactobacillus sp., Carnobacterium sp.), and survival during biltong processing (Latilactobacillus sakei). The presence of these organisms on raw beef and their growth during conditions of beef storage appears to 'front-load' the raw beef with non-pathogenic organisms that are present at high levels leading into biltong processing. As shown in our prior study on the use of surrogate organisms, L. sakei is resistant to the biltong process (i.e., 2-log reduction), whereas Carnobacterium sp. demonstrated a 5-log reduction in the process; the recovery of either psychrotroph after biltong processing may be dependent on which was more prevalent on the raw beef. This phenomenon of psychrotrophic bloom during refrigerated storage of raw beef may result in a natural microbial suppression of mesophilic foodborne pathogens that are further reduced during biltong processing and contributes to the safety of this type of air-dried beef.
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Affiliation(s)
- Caitlin Karolenko
- Robert M. Kerr Food and Agricultural Products Center, Oklahoma State University, Stillwater, OK 74078, USA
- Department of Animal and Food Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Udaya DeSilva
- Department of Animal and Food Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Peter M. Muriana
- Robert M. Kerr Food and Agricultural Products Center, Oklahoma State University, Stillwater, OK 74078, USA
- Department of Animal and Food Sciences, Oklahoma State University, Stillwater, OK 74078, USA
- Correspondence: ; Tel.: +1-405-744-5563
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6
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Leech SM, Gilbert MC, Clifton VL, Kumar S, Rae KM, Borg D, Dekker Nitert M. Insufficient Evidence of a Breastmilk Microbiota at Six-Weeks Postpartum: A Pilot Study. Nutrients 2023; 15:nu15030696. [PMID: 36771402 PMCID: PMC9919471 DOI: 10.3390/nu15030696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/25/2023] [Accepted: 01/28/2023] [Indexed: 01/31/2023] Open
Abstract
Breastmilk is thought to influence the infant gut by supplying prebiotics in the form of human milk oligosaccharides and potentially seeding the gut with breastmilk microbes. However, the presence of a breastmilk microbiota and origins of these microbes are still debated. As a pilot study, we assessed the microbes present in expressed breastmilk at six-weeks postpartum using shotgun metagenomic sequencing in a heterogenous cohort of women who delivered by vaginal (n = 8) and caesarean delivery (n = 8). In addition, we estimated the microbial load of breastmilk at six-weeks post-partum with quantitative PCR targeting the 16S rRNA gene. Breastmilk at six-weeks postpartum had a low microbial mass, comparable with PCR no-template and extraction controls. Microbes identified through metagenomic sequencing were largely consistent with skin and oral microbes, with four samples returning no identifiable bacterial sequences. Our results do not provide convincing evidence for the existence of a breastmilk microbiota at six-weeks postpartum. It is more likely that microbes present in breastmilk are sourced by ejection from the infant's mouth and from surrounding skin, as well as contamination during sampling and processing.
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Affiliation(s)
- Sophie M. Leech
- School of Chemistry and Molecular Biosciences, The University of Queensland, Saint Lucia, QLD 4072, Australia
| | - Morgan C. Gilbert
- School of Chemistry and Molecular Biosciences, The University of Queensland, Saint Lucia, QLD 4072, Australia
| | - Vicki L. Clifton
- Pregnancy and Development Group, Mater Research Institute, South Brisbane, QLD 4101, Australia
- Faculty of Medicine, The University of Queensland, Saint Lucia, QLD 4072, Australia
| | - Sailesh Kumar
- Faculty of Medicine, The University of Queensland, Saint Lucia, QLD 4072, Australia
- Centre for Maternal and Fetal Medicine, Mater Mothers’ Hospital, Brisbane, QLD 4101, Australia
| | - Kym M. Rae
- Faculty of Medicine, The University of Queensland, Saint Lucia, QLD 4072, Australia
- Indigenous Health, Mater Research Institute, South Brisbane, QLD 4101, Australia
| | - Danielle Borg
- Pregnancy and Development Group, Mater Research Institute, South Brisbane, QLD 4101, Australia
- Faculty of Medicine, The University of Queensland, Saint Lucia, QLD 4072, Australia
| | - Marloes Dekker Nitert
- School of Chemistry and Molecular Biosciences, The University of Queensland, Saint Lucia, QLD 4072, Australia
- Correspondence:
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Stinson LF, Ma J, Sindi AS, Geddes DT. Methodological approaches for studying the human milk microbiome. Nutr Rev 2022; 81:705-715. [PMID: 36130405 DOI: 10.1093/nutrit/nuac082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Human milk contains a low-biomass, low-diversity microbiome, consisting largely of bacteria. This community is of great research interest in the context of infant health and maternal and mammary health. However, this sample type presents many unique methodological challenges. In particular, there are numerous technical considerations relating to sample collection and storage, DNA extraction and sequencing, viability, and contamination. Failure to properly address these challenges may lead to distortion of bacterial DNA profiles generated from human milk samples, ultimately leading to spurious conclusions. Here, these technical challenges are discussed, and various methodological approaches used to address them are analyzed. Data were collected from studies in which a breadth of methodological approaches were used, and recommendations for robust and reproducible analysis of the human milk microbiome are proposed. Such methods will ensure high-quality data are produced in this field, ultimately supporting better research outcomes for mothers and infants.
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Affiliation(s)
- Lisa F Stinson
- School of Molecular Sciences, The University of Western Australia, Perth, Australia
| | - Jie Ma
- School of Molecular Sciences, The University of Western Australia, Perth, Australia
| | - Azhar S Sindi
- Division of Obstetrics and Gynaecology, School of Medicine, The University of Western Australia, Perth, Australia.,is with the College of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Donna T Geddes
- School of Molecular Sciences, The University of Western Australia, Perth, Australia
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8
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Comparison of the Effectiveness of Four Commercial DNA Extraction Kits on Fresh and Frozen Human Milk Samples. Methods Protoc 2022; 5:mps5040063. [PMID: 35893589 PMCID: PMC9326650 DOI: 10.3390/mps5040063] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 11/23/2022] Open
Abstract
For-profit donor human milk organizations have DNA-based proprietary methodology for testing incoming milk for adulteration with other species’ milk. However, there is currently no standardized methodology for extracting DNA from human milk. Microbiome research has shown that DNA purity and quantity can vary depending on the extraction methodology and storage conditions. This study assessed the purity and quantity of DNA extracted from four commercially available DNA extraction kits—including one kit that was developed for human milk. This study was for method validation only. One donor provided a 90 mL human milk sample. The sample was aliquoted into 70 × 1 mL microcentrifuge tubes. Aliquots were randomized into one of three categories: fresh extraction, extraction after freezing, and extraction after purification and storage at room temperature. DNA was analyzed for purity and quantity using a NanoDrop Spectrophotometer. Results confirmed differences in DNA purity and quantity between extraction kits. The Plasma/Serum Circulating DNA Purification Mini Kit (Norgen Biotek, ON, Canada) provided significantly more DNA, and consistent purity as measured by 260/280 and 260/230 ratios. DNA quantity and purity were similar between fresh and frozen human milk samples. These results suggest that DNA purity and quantity is highest and most consistent when extracted from human milk using the Plasma/Serum Circulating DNA Purification Mini Kit amongst the kits tested in this study. Standardized methodology for extracting DNA from human milk is necessary for improvement of research in the field of human milk. To do this, future studies are recommended for optimization of DNA extraction from human milk using larger sample sizes and multiple donor parents.
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9
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Xie W, Zhang H, Ni Y, Peng Y. Contrasting Diversity and Composition of Human Colostrum Microbiota in a Maternal Cohort With Different Ethnic Origins but Shared Physical Geography (Island Scale). Front Microbiol 2022; 13:934232. [PMID: 35903466 PMCID: PMC9315263 DOI: 10.3389/fmicb.2022.934232] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/22/2022] [Indexed: 12/19/2022] Open
Abstract
Colostrum represents an important source for the transfer of important commensal bacteria from mother to newborn and has a strong impact on the newborn’s health after birth. However, the composition of the colostrum microbiome is highly heterogeneous due to geographic factors and ethnicity (maternal, cultural, and subsistence factors). By analyzing the colostrum 16S rRNA gene full-length sequencing dataset in 97 healthy mothers (60 from Han, 37 from Li) from the Hainan island of China, we showed that the ethnic differences of the colostrum microbiome in a maternal cohort with different ethnic origins shared physical geography. Results indicated that the richness of microbial community in colostrum of Han women was higher than that of Li women, but there was no significant difference in Shannon index and invsimpson index between the two groups. Visualization analysis based on the distance showed an obvious ethnicity-associated structural segregation of colostrum microbiota. The relative abundance of Firmicutes was higher in the microbiota of the Han group than in Li’s, while Proteobacteria was on the contrary. At the genus level, the most dominant members of the Han and Li ethnic groups were Acinetobacter and Cupriavidus, two common environmental bacteria, respectively, although skin-derived Staphylococcus and Streptococcus were still subdominant taxa. Cupriavidus lacunae was the most dominant species in the Li group, accounting for 26.10% of the total bacterial community, but only 3.43% for the Han group with the most dominant Staphylococcus petrasii (25.54%), indicating that human colostrum microbiome was more susceptible to local living environmental factors. Hence, the ethnic origin of individuals may be an important factor to consider in human milk microbiome research and its potential clinical significance during the perinatal period in ethnic-diverse societies, even within a small geographic scale.
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Affiliation(s)
- Wanying Xie
- Department of Obstetrics and Gynecology, Hainan Medical University, Haikou, China
| | - Huimin Zhang
- School of Food Science and Technology, Shihezi University, Xinjiang, China
| | - Yongqing Ni
- School of Food Science and Technology, Shihezi University, Xinjiang, China
- *Correspondence: Yongqing Ni,
| | - Yunhua Peng
- Department of Obstetrics and Gynecology, Hainan Medical University, Haikou, China
- The First Affiliated Hospital of Hainan Medical University, Haikou, China
- Yunhua Peng,
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10
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Shi Y, Wang G, Lau HCH, Yu J. Metagenomic Sequencing for Microbial DNA in Human Samples: Emerging Technological Advances. Int J Mol Sci 2022; 23:ijms23042181. [PMID: 35216302 PMCID: PMC8877284 DOI: 10.3390/ijms23042181] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/06/2022] [Accepted: 02/11/2022] [Indexed: 02/04/2023] Open
Abstract
Whole genome metagenomic sequencing is a powerful platform enabling the simultaneous identification of all genes from entirely different kingdoms of organisms in a complex sample. This technology has revolutionised multiple areas from microbiome research to clinical diagnoses. However, one of the major challenges of a metagenomic study is the overwhelming non-microbial DNA present in most of the host-derived specimens, which can inundate the microbial signals and reduce the sensitivity of microorganism detection. Various host DNA depletion methods to facilitate metagenomic sequencing have been developed and have received considerable attention in this context. In this review, we present an overview of current host DNA depletion approaches along with explanations of their underlying principles, advantages and disadvantages. We also discuss their applications in laboratory microbiome research and clinical diagnoses and, finally, we envisage the direction of the further perfection of metagenomic sequencing in samples with overabundant host DNA.
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Affiliation(s)
| | | | | | - Jun Yu
- Correspondence: ; Tel.: +852-37636099; Fax:+852-21445330
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Bovine Milk Microbiota: Comparison among Three Different DNA Extraction Protocols To Identify a Better Approach for Bacterial Analysis. Microbiol Spectr 2021; 9:e0037421. [PMID: 34550002 PMCID: PMC8557886 DOI: 10.1128/spectrum.00374-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The bovine udder is colonized by a huge quantity of microorganisms that constitute the intramammary ecosystem, with a specific role in modulating not only udder homeostasis and mastitis susceptibility, but also the quality of the dairy products. However, generating high-quality bacterial DNA can be critical, especially starting from a complex biological matrix like milk, characterized by high fat, protein, and calcium contents. Here, bacterial DNA was recovered from a commercial ultra-high-temperature (UHT) milk sample artificially spiked with a predetermined mock community composition and from three bulk tank milk (raw milk) samples. The DNA was isolated using three different protocols to evaluate the effect of the extraction procedures on the milk microbiota composition. In the mock community experiment, the bacterial profiles generated by the three DNA extraction protocols were profoundly different, with the genera Staphylococcus, Lactobacillus, Listeria, and Salmonella underestimated by all the protocols. Only one protocol revealed values close to the expected abundances for Escherichia/Shigella spp., Bacillus spp., Enterococcus spp., and Pseudomonas spp. On the other hand, the nonspiked UHT milk sample exhibited a similar microbiota composition, revealing the prevalence of Acinetobacter spp., for all the DNA extraction protocols. For the raw milk samples, the three DNA extraction kits performed differently, revealing significant separations in both the microbial richness (alpha diversity) and composition (beta diversity). Our study highlights the presence of significant differences among these procedures, probably due to the different DNA extracting capacities and to the different properties of the milk samples, revealing that the selection of DNA extraction protocol is a critical point. IMPORTANCE The advance of high-throughput technologies has increased our knowledge of the world of microorganisms, especially of microbial populations inhabiting living animals. This study provides evidence that milk, as other complex sources, could be critical for generating high-quality DNA for microbiota analysis. In addition, it demonstrates that the microbial population highlighted by metagenomic studies changes in relation to different DNA extraction procedures, revealing that attention should be paid especially when comparing different studies.
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Petrov ME, Jiao N, Panchanathan SS, Reifsnider E, Coonrod DV, Liu L, Krajmalnik-Brown R, Gu H, Davidson LA, Chapkin RS, Whisner CM. Protocol of the Snuggle Bug/Acurrucadito Study: a longitudinal study investigating the influences of sleep-wake patterns and gut microbiome development in infancy on rapid weight gain, an early risk factor for obesity. BMC Pediatr 2021; 21:374. [PMID: 34465311 PMCID: PMC8405858 DOI: 10.1186/s12887-021-02832-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/09/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Overweight, obesity, and associated comorbidities are a pressing global issue among children of all ages, particularly among low-income populations. Rapid weight gain (RWG) in the first 6 months of infancy contributes to childhood obesity. Suboptimal sleep-wake patterns and gut microbiota (GM) have also been associated with childhood obesity, but little is known about their influences on early infant RWG. Sleep may alter the GM and infant metabolism, and ultimately impact obesity; however, data on the interaction between sleep-wake patterns and GM development on infant growth are scarce. In this study, we aim to investigate associations of infant sleep-wake patterns and GM development with RWG at 6 months and weight gain at 12 months. We also aim to evaluate whether temporal interactions exist between infant sleep-wake patterns and GM, and if these relations influence RWG. METHODS The Snuggle Bug/ Acurrucadito study is an observational, longitudinal study investigating whether 24-h, actigraphy-assessed, sleep-wake patterns and GM development are associated with RWG among infants in their first year. Based on the Ecological Model of Growth, we propose a novel conceptual framework to incorporate sleep-wake patterns and the GM as metabolic contributors for RWG in the context of maternal-infant interactions, and familial and socio-physical environments. In total, 192 mother-infant pairs will be recruited, and sleep-wake patterns and GM development assessed at 3 and 8 weeks, and 3, 6, 9, and 12 months postpartum. Covariates including maternal and child characteristics, family and environmental factors, feeding practices and dietary intake of infants and mothers, and stool-derived metabolome and exfoliome data will be assessed. The study will apply machine learning techniques combined with logistic time-varying effect models to capture infant growth and aid in elucidating the dynamic associations between study variables and RWG. DISCUSSION Repeated, valid, and objective assessment at clinically and developmentally meaningful intervals will provide robust measures of longitudinal sleep, GM, and growth. Project findings will provide evidence for future interventions to prevent RWG in infancy and subsequent obesity. The work also may spur the development of evidence-based guidelines to address modifiable factors that influence sleep-wake and GM development and prevent childhood obesity.
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Affiliation(s)
- Megan E Petrov
- Edson College of Nursing and Health Innovation, Arizona State University, 550 N. 3rd Street, Suite 301, Phoenix, AZ, 85004, USA
| | - Nana Jiao
- Edson College of Nursing and Health Innovation, Arizona State University, 550 N. 3rd Street, Suite 301, Phoenix, AZ, 85004, USA
| | - Sarada S Panchanathan
- Valleywise Comprehensive Health Center - Phoenix (Pediatric Clinic), 2525 E. Roosevelt St., Phoenix, AZ, 85008, USA
- College of Medicine Phoenix, University of Arizona, Phoenix, AZ, 85007, USA
| | - Elizabeth Reifsnider
- Edson College of Nursing and Health Innovation, Arizona State University, 550 N. 3rd Street, Suite 301, Phoenix, AZ, 85004, USA
| | - Dean V Coonrod
- Valleywise Health, Department of Obstetrics and Gynecology, 2525 E. Roosevelt St., Phoenix, AZ, 85008, USA
| | - Li Liu
- Biodesign Institute, Arizona State University, 1001 S. McAllister Ave BDA230B, Tempe, AZ, 85287, USA
| | - Rosa Krajmalnik-Brown
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave, PO Box 875701, Tempe, AZ, 85287, USA
| | - Haiwei Gu
- College of Health Solutions, Arizona State University, 550 N. 3rd. Street, Suite 501, Phoenix, AZ, 85004, USA
| | - Laurie A Davidson
- Department of Nutrition and Food Science, Program in Integrative Nutrition and Complex Diseases, Texas A&M University, 2253 TAMU, 112 Cater-Mattil, College Station, TX, 77843, USA
| | - Robert S Chapkin
- Department of Nutrition and Food Science, Program in Integrative Nutrition and Complex Diseases, Texas A&M University, 2253 TAMU, 112 Cater-Mattil, College Station, TX, 77843, USA
| | - Corrie M Whisner
- College of Health Solutions, Arizona State University, 550 N. 3rd. Street, Suite 501, Phoenix, AZ, 85004, USA.
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Janssen K, Low SL, Wang Y, Mu Q, Bierbaum G, Gee CT. Elucidating biofilm diversity on water lily leaves through 16S rRNA amplicon analysis: Comparison of four DNA extraction kits. APPLICATIONS IN PLANT SCIENCES 2021; 9:e11444. [PMID: 34504737 PMCID: PMC8419396 DOI: 10.1002/aps3.11444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
PREMISE Within a broader study on leaf fossilization in freshwater environments, a long-term study on the development and microbiome composition of biofilms on the foliage of aquatic plants has been initiated to understand how microbes and biofilms contribute to leaf decay and preservation. Here, water lily leaves are employed as a study model to investigate the relationship between bacterial microbiomes, biodegradation, and fossilization. We compare four DNA extraction kits to reduce biases in interpretation and to identify the most suitable kit for the extraction of DNA from bacteria associated with biofilms on decaying water lily leaves for 16S rRNA amplicon analysis. METHODS We extracted surface-associated DNA from Nymphaea leaves in early stages of decay at two water depth levels using four commercially available kits to identify the most suitable protocol for bacterial extraction, applying a mock microbial community standard to enable a reliable comparison of the kits. RESULTS Kit 4, the FastDNA Spin Kit for Soil, resulted in high DNA concentrations with better quality and yielded the most accurate depiction of the mock community. Comparison of the leaves at two water depths showed no significant differences in community composition. DISCUSSION The success of Kit 4 may be attributed to its use of bead beating with a homogenizer, which was more efficient in the lysis of Gram-positive bacteria than the manual vortexing protocols used by the other kits. Our results show that microbial composition on leaves during early decay remains comparable and may change only in later stages of decomposition.
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Affiliation(s)
- Kathrin Janssen
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinic of Bonn, Rheinische Friedrich‐Wilhelms‐University Bonn, Venusberg‐Campus 153127BonnGermany
| | - Shook Ling Low
- Institute of Geosciences, Division of PaleontologyRheinische Friedrich‐Wilhelms‐University Bonn, Nussallee 853115BonnGermany
| | - Yan Wang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of SciencesMengla666303China
| | - Qi‐Yong Mu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of SciencesMengla666303China
| | - Gabriele Bierbaum
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinic of Bonn, Rheinische Friedrich‐Wilhelms‐University Bonn, Venusberg‐Campus 153127BonnGermany
| | - Carole T. Gee
- Institute of Geosciences, Division of PaleontologyRheinische Friedrich‐Wilhelms‐University Bonn, Nussallee 853115BonnGermany
- Huntington Botanical Gardens1151 Oxford Road, San MarinoCalifornia91108USA
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14
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Low L, Fuentes-Utrilla P, Hodson J, O’Neil JD, Rossiter AE, Begum G, Suleiman K, Murray PI, Wallace GR, Loman NJ, Rauz S. Evaluation of full-length nanopore 16S sequencing for detection of pathogens in microbial keratitis. PeerJ 2021; 9:e10778. [PMID: 33628638 PMCID: PMC7891086 DOI: 10.7717/peerj.10778] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 12/22/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Microbial keratitis is a leading cause of preventable blindness worldwide. Conventional sampling and culture techniques are time-consuming, with over 40% of cases being culture-negative. Nanopore sequencing technology is portable and capable of generating long sequencing reads in real-time. The aim of this study is to evaluate the potential of nanopore sequencing directly from clinical samples for the diagnosis of bacterial microbial keratitis. METHODS Using full-length 16S rRNA amplicon sequences from a defined mock microbial community, we evaluated and benchmarked our bioinformatics analysis pipeline for taxonomic assignment on three different 16S rRNA databases (NCBI 16S RefSeq, RDP and SILVA) with clustering at 97%, 99% and 100% similarities. Next, we optimised the sample collection using an ex vivo porcine model of microbial keratitis to compare DNA recovery rates of 12 different collection methods: 21-gauge needle, PTFE membrane (4 mm and 6 mm), Isohelix™ SK-2S, Sugi® Eyespear, Cotton, Rayon, Dryswab™, Hydraflock®, Albumin-coated, Purflock®, Purfoam and Polyester swabs. As a proof-of-concept study, we then used the sampling technique that provided the highest DNA recovery, along with the optimised bioinformatics pipeline, to prospectively collected samples from patients with suspected microbial keratitis. The resulting nanopore sequencing results were then compared to standard microbiology culture methods. RESULTS We found that applying alignment filtering to nanopore sequencing reads and aligning to the NCBI 16S RefSeq database at 100% similarity provided the most accurate bacterial taxa assignment. DNA concentration recovery rates differed significantly between the collection methods (p < 0.001), with the Sugi® Eyespear swab providing the highest mean rank of DNA concentration. Then, applying the optimised collection method and bioinformatics pipeline directly to samples from two patients with suspected microbial keratitis, sequencing results from Patient A were in agreement with culture results, whilst Patient B, with negative culture results and previous antibiotic use, showed agreement between nanopore and Illumina Miseq sequencing results. CONCLUSION We have optimised collection methods and demonstrated a novel workflow for identification of bacterial microbial keratitis using full-length 16S nanopore sequencing.
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Affiliation(s)
- Liying Low
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, West Midlands, UK
- Birmingham and Midland Eye Centre, Sandwell and West Birmingham Hospitals National Health Service (NHS) Trust, Birmingham, West Midlands, UK
| | - Pablo Fuentes-Utrilla
- MicrobesNG/School of Biosciences, University of Birmingham, Birmingham, West Midlands, UK
| | - James Hodson
- Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, West Midlands, UK
| | - John D. O’Neil
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, West Midlands, UK
| | - Amanda E. Rossiter
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, West Midlands, UK
| | - Ghazala Begum
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, West Midlands, UK
- National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre, Birmingham, UK
| | - Kusy Suleiman
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, West Midlands, UK
| | - Philip I. Murray
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, West Midlands, UK
- Birmingham and Midland Eye Centre, Sandwell and West Birmingham Hospitals National Health Service (NHS) Trust, Birmingham, West Midlands, UK
| | - Graham R. Wallace
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, West Midlands, UK
- Birmingham and Midland Eye Centre, Sandwell and West Birmingham Hospitals National Health Service (NHS) Trust, Birmingham, West Midlands, UK
| | - Nicholas J. Loman
- MicrobesNG/School of Biosciences, University of Birmingham, Birmingham, West Midlands, UK
| | - Saaeha Rauz
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, West Midlands, UK
- Birmingham and Midland Eye Centre, Sandwell and West Birmingham Hospitals National Health Service (NHS) Trust, Birmingham, West Midlands, UK
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15
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Cheema AS, Lai CT, Dymock M, Rae A, Geddes DT, Payne MS, Stinson LF. Impact of expression mode and timing of sample collection, relative to milk ejection, on human milk bacterial DNA profiles. J Appl Microbiol 2021; 131:988-995. [PMID: 33421237 DOI: 10.1111/jam.14998] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/21/2020] [Accepted: 01/02/2021] [Indexed: 01/16/2023]
Abstract
AIM To investigate the impact of expression mode: electric breast pump or hand expression, and timing of sample collection: pre- and post-milk ejection on human milk (HM) bacterial DNA profiles. METHODS AND RESULTS Three HM samples from the same breast were collected from 30 breastfeeding mothers: a pre-milk ejection pump-expressed sample (pre-pump), a post-milk ejection pump-expressed sample (post-pump) and a post-milk ejection hand-expressed sample (post-hand). Full-length 16S rRNA gene sequencing was used to assess milk bacterial DNA profiles. Bacterial profiles did not differ significantly based on mode of expression nor timing of sample collection. No significant differences were detected in the relative abundance of any OTUs based on expression condition (pre-pump/ post-pump and post-pump/post-hand) with univariate linear mixed-effects regression analyses (all P-values > 0·01; α = 0·01). Similarly, no difference in richness was observed between sample types (number of observed OTUs: post-pump/post-hand P = 0·13; pre-pump/post-pump P = 0. 45). CONCLUSION Bacterial DNA profiles of HM did not differ according to either expression method or timing of sample collection. SIGNIFICANCE AND IMPACT OF THE STUDY Hand or pump expression can be utilized to collect samples for microbiome studies. This has implications for the design of future HM microbiome studies.
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Affiliation(s)
- A S Cheema
- School of Molecular Sciences, Faculty of Science, The University of Western Australia, Perth, WA, Australia
| | - C T Lai
- School of Molecular Sciences, Faculty of Science, The University of Western Australia, Perth, WA, Australia
| | - M Dymock
- Centre for Applied Statistics, Department of Mathematics and Statistics, Faculty of Engineering and Mathematical Sciences, The University of Western Australia, Perth, WA, Australia
| | - A Rae
- Mathematics and Statistics, School of Engineering and Information Technology, Murdoch University, Perth, WA, Australia
| | - D T Geddes
- School of Molecular Sciences, Faculty of Science, The University of Western Australia, Perth, WA, Australia
| | - M S Payne
- Division of Obstetrics and Gynaecology, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, WA, Australia
| | - L F Stinson
- School of Molecular Sciences, Faculty of Science, The University of Western Australia, Perth, WA, Australia
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16
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Moossavi S, Fontes ME, Rossi L, Fusch G, Surette MG, Azad MB. Capturing the diversity of the human milk microbiota through culture-enriched molecular profiling: a feasibility study. FEMS Microbiol Lett 2021; 368:6070652. [PMID: 33417698 DOI: 10.1093/femsle/fnab001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 01/05/2021] [Indexed: 12/19/2022] Open
Abstract
Previous human milk studies have confirmed the existence of a highly diverse bacterial community using culture-independent and targeted culture-dependent techniques. However, culture-enriched molecular profiling of milk microbiota has not been done. Additionally, the impact of storage conditions and milk fractionation on microbiota composition is not understood. In this feasibility study, we optimized and applied culture-enriched molecular profiling to study culturable milk microbiota in eight milk samples collected from mothers of infants admitted to a neonatal intensive care unit. Fresh samples were immediately plated or stored at -80°C for 2 weeks (short-term frozen). Long-term samples were stored at -20°C for >6 months. Samples were cultured using 10 different culture media and incubated both aerobically and anaerobically. We successfully isolated major milk bacteria, including Streptococcus, Staphylococcus and Bifidobacterium, from fresh milk samples, but were unable to culture any bacteria from the long-term frozen samples. Short-term freezing shifted the composition of viable milk bacteria from the original composition in fresh samples. Nevertheless, the inter-individual variability of milk microbiota composition was observed even after short-term storage. There was no major difference in the overall milk microbiota composition between milk fractions in this feasibility study. This is among the first studies on culture-enriched molecular profiling of the milk microbiota demonstrating the effect of storage and fractionation on milk microbiota composition.
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Affiliation(s)
- Shirin Moossavi
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.,Manitoba Interdisciplinary Lactation Centre (MILC), Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada.,Digestive Oncology Research Center, Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran 14117-13135, Iran.,Microbiome and Microbial Ecology Interest Group (MMEIG), Universal Scientific Education and Research Network (USERN), Calgary, AB T2N 4Z1, Canada
| | - Michelle E Fontes
- Department of Medicine and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Laura Rossi
- Department of Medicine and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Gerhard Fusch
- Department of Pediatrics, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Michael G Surette
- Department of Medicine and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada.,Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Meghan B Azad
- Manitoba Interdisciplinary Lactation Centre (MILC), Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada.,Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB R3A 1S1, Canada
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17
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Lyons KE, Fouhy F, O’ Shea C, Ryan CA, Dempsey EM, Ross RP, Stanton C. Effect of storage, temperature, and extraction kit on the phylogenetic composition detected in the human milk microbiota. Microbiologyopen 2021; 10:e1127. [PMID: 33373099 PMCID: PMC7841076 DOI: 10.1002/mbo3.1127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 01/10/2023] Open
Abstract
Human milk is considered the optimum feeding regime for newborns and is a source of bacteria for the developing infant gastrointestinal tract. However, as with all low biomass samples, standardization across variabilities such as sample collection, storage, and extraction methods is needed to eliminate discrepancies in microbial composition across studies. The aim of this study was to investigate how different storage methods, temperatures, preservatives, and extraction kits influence the human milk microbiome, compared to fresh samples. Breast milk samples were processed via six different methods: fresh (Method 1), frozen at -80°C (Method 2), treated with RNAlater and stored at 4°C or -80°C (Methods 3 and 4), and treated with Milk Preservation Solution at room temperature (Methods 5 and 6). Methods 1-5 were extracted using PowerFoodTM Microbial DNA Isolation kit (Mobio), and Method 6 was extracted using Milk DNA Preservation and Isolation kit (Norgen BioTek). At genus level, the most abundant genera were shared across Methods 1-5. Samples frozen at -80°C had fewest significant changes while samples treated and extracted using Milk Preservation and Isolation kit had the most significant changes when compared to fresh samples. Diversity analysis indicated that variation in microbiota composition was related to the method and extraction kit used. This study highlighted that, when extraction from fresh milk samples is not an option, freezing at -80°C is the next best option to preserve the integrity of the milk microbiome. Furthermore, our results demonstrate that choice of extraction kit had a profound impact on the microbiota populations detected in milk.
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Affiliation(s)
- Katriona E. Lyons
- Teagasc Food Research CentreMoorepark, Fermoy, Co.CorkIreland
- School of MicrobiologyUniversity College CorkCorkIreland
| | - Fiona Fouhy
- Teagasc Food Research CentreMoorepark, Fermoy, Co.CorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
| | | | - C. Anthony Ryan
- APC Microbiome IrelandUniversity College CorkCorkIreland
- Department of NeonatologyCork University Maternity HospitalCorkIreland
| | - Eugene M. Dempsey
- APC Microbiome IrelandUniversity College CorkCorkIreland
- Department of NeonatologyCork University Maternity HospitalCorkIreland
| | - R. Paul Ross
- APC Microbiome IrelandUniversity College CorkCorkIreland
| | - Catherine Stanton
- Teagasc Food Research CentreMoorepark, Fermoy, Co.CorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
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Cheema AS, Stinson LF, Lai CT, Geddes DT, Payne MS. DNA extraction method influences human milk bacterial profiles. J Appl Microbiol 2020; 130:142-156. [PMID: 32654260 DOI: 10.1111/jam.14780] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/01/2020] [Accepted: 07/06/2020] [Indexed: 12/19/2022]
Abstract
AIMS To evaluate four DNA extraction methods to elucidate the most effective method for bacterial DNA recovery from human milk (HM). METHODS AND RESULTS Human milk DNA was extracted using the following methods: (i) Qiagen MagAttract Microbial DNA Isolation Kit (kit QM), (ii) Norgen Milk Bacterial DNA Isolation Kit (kit NM), (iii) Qiagen MagAttract Microbiome DNA/RNA Isolation Kit (kit MM) and (iv) TRIzol LS Reagent (method LS). The full-length 16S rRNA gene was sequenced. Kits MM and method LS were unable to extract detectable levels of DNA in 9/11 samples. Detectable levels of DNA were recovered from all samples using kits NM (mean = 0·68 ng μl-1 ) and QM (mean = 0·55 ng μl-1 ). For kits NM and QM, the greatest number of reads were associated with Staphylococcus epidermidis, Streptococcus vestibularis, Propionibacterium acnes, Veillonella dispar and Rothia mucilaginosa. Contamination profiles varied substantially between kits, with one bacterial species detected in negative extraction controls generated with kit QM and six with kit NM. CONCLUSIONS Kit QM is the most suitable of the kits tested for the extraction of bacterial DNA from human milk. SIGNIFICANCE AND IMPACT OF THE STUDY Choice of extraction method impacts the efficiency of bacterial DNA extraction from human milk and the resultant bacterial community profiles generated from these samples.
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Affiliation(s)
- A S Cheema
- School of Molecular Sciences, The University of Western Australia, Perth, WA, Australia
| | - L F Stinson
- School of Molecular Sciences, The University of Western Australia, Perth, WA, Australia
| | - C T Lai
- School of Molecular Sciences, The University of Western Australia, Perth, WA, Australia
| | - D T Geddes
- School of Molecular Sciences, The University of Western Australia, Perth, WA, Australia
| | - M S Payne
- Division of Obstetrics and Gynaecology, The University of Western Australia, Perth, WA, Australia
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