A comparison of blood agar supplemented with NAD with plain blood agar and chocolated blood agar in the isolation of Streptococcus pneumoniae and Haemophilus influenzae from sputum

Nye, K.; Fallon, D.; Gee, B.; Messer, S. A.; Warren, Richard M.; Andrews, Nicholas

doi:10.1099/00222615-48-12-1111

Cited by 8 publications

(3 citation statements)

References 6 publications

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“…Laboratory settings can also generate toxic conditions, such as oxidative stress (Morris et al, 2011 ; Tanaka et al, 2014 ). In addition to this, organisms might fail to grow due to missing pathways (Nye et al, 1999 ), or be dependent on siderophores produced by other members of their community (D'Onofrio et al, 2010 ).…”

Section: A Brief History Of Methodologies For Determining Microbial Cmentioning

confidence: 99%

Analysing Microbial Community Composition through Amplicon Sequencing: From Sampling to Hypothesis Testing

2017

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Microbial ecology as a scientific field is fundamentally driven by technological advance. The past decade's revolution in DNA sequencing cost and throughput has made it possible for most research groups to map microbial community composition in environments of interest. However, the computational and statistical methodology required to analyse this kind of data is often not part of the biologist training. In this review, we give a historical perspective on the use of sequencing data in microbial ecology and restate the current need for this method; but also highlight the major caveats with standard practices for handling these data, from sample collection and library preparation to statistical analysis. Further, we outline the main new analytical tools that have been developed in the past few years to bypass these caveats, as well as highlight the major requirements of common statistical practices and the extent to which they are applicable to microbial data. Besides delving into the meaning of select alpha- and beta-diversity measures, we give special consideration to techniques for finding the main drivers of community dissimilarity and for interaction network construction. While every project design has specific needs, this review should serve as a starting point for considering what options are available.

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Section: A Brief History Of Methodologies For Determining Microbial Cmentioning

confidence: 99%

Analysing Microbial Community Composition through Amplicon Sequencing: From Sampling to Hypothesis Testing

2017

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“…While blood normally contains NAD, blood from sheep and other animals commonly used as a source of blood for culture media also contains enzymes that can destroy this factor (5, 42). The dependence of H. influenzae on S. aureus can be overcome by preheating the blood used in the petri plates (creating the oddly named "chocolate" agar); this heat treatment both releases heme and inactivates the enzyme that breaks down NAD (25,57). Perhaps because the host, rather than S. aureus, was apparently the ultimate source of these factors, these observations did not directly lead to systematic coculturing efforts for other bacteria.…”

Section: Approaches To Culturing the Missing Bacterial Diversitymentioning

confidence: 98%

Growing Unculturable Bacteria

2012

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The bacteria that can be grown in the laboratory are only a small fraction of the total diversity that exists in nature. At all levels of bacterial phylogeny, uncultured clades that do not grow on standard media are playing critical roles in cycling carbon, nitrogen, and other elements, synthesizing novel natural products, and impacting the surrounding organisms and environment. While molecular techniques, such as metagenomic sequencing, can provide some information independent of our ability to culture these organisms, it is essentially impossible to learn new gene and pathway functions from pure sequence data. A true understanding of the physiology of these bacteria and their roles in ecology, host health, and natural product production requires their cultivation in the laboratory. Recent advances in growing these species include coculture with other bacteria, recreating the environment in the laboratory, and combining these approaches with microcultivation technology to increase throughput and access rare species. These studies are unraveling the molecular mechanisms of unculturability and are identifying growth factors that promote the growth of previously unculturable organisms. This minireview summarizes the recent discoveries in this area and discusses the potential future of the field. What is an unculturable bacterium? While at first glance, there appears to be a contradiction in the title of this review, in this context, "unculturable" indicates that current laboratory culturing techniques are unable to grow a given bacterium in the laboratory. That all organisms must be growing in their natural environment is axiomatic; that many we cannot currently grow will be cultured in the future is certain. Therefore, "unculturable" does not mean "can never be cultured" but, rather, signifies that we lack critical information on their biology, and this presents both challenges and opportunities. These opportunities are the chance to learn the molecular principles behind this recalcitrant growth, allowing us to add that information to our repertoire of microbiological techniques and gaining access to previously hidden metabolic diversity that will provide new natural products and reveal factors that can contribute to both ecological balance and host health. This review examines the recent approaches that microbiologists are employing to convert currently unculturable bacteria into cultured isolates in the laboratory while concurrently beginning to discover the mechanisms behind their apparent unculturability.

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“…The definitions of clarithromycin and ampicillin resistance were based on the breakpoints by CLSI (14). H. influenzae was cultured on chocolate agar and in supplemented brain heart infusion (sBHI) broth, which contains NAD (15 g/ml) and hemin (15 g/ml) added to BHI broth (Oxoid, Hampshire, United Kingdom), at 37°C for 24 h in 5% CO 2 (15).…”

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confidence: 99%

Clarithromycin Resistance Mechanisms of Epidemic β-Lactamase-Nonproducing Ampicillin-Resistant Haemophilus influenzae Strains in Japan

Seyama

Wajima

Nakaminami

et al. 2016

Antimicrob Agents Chemother

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The aim of this study was to clarify the clarithromycin resistance mechanisms of ␤-lactamase-nonproducing ampicillin-resistant Haemophilus influenzae strains. In all clarithromycin-resistant strains, the transcript level of acrB was significantly elevated, and these strains had a frameshift mutation in acrR. Introduction of the acrR mutation into H. influenzae Rd generated a clarithromycin-resistant transformant with the same MIC as the donor strain. Our results indicate that the acrR mutation confers clarithromycin resistance by the increasing the transcription of acrB.

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A comparison of blood agar supplemented with NAD with plain blood agar and chocolated blood agar in the isolation of Streptococcus pneumoniae and Haemophilus influenzae from sputum

Cited by 8 publications

References 6 publications

Analysing Microbial Community Composition through Amplicon Sequencing: From Sampling to Hypothesis Testing

Analysing Microbial Community Composition through Amplicon Sequencing: From Sampling to Hypothesis Testing

Growing Unculturable Bacteria

Clarithromycin Resistance Mechanisms of Epidemic β-Lactamase-Nonproducing Ampicillin-Resistant Haemophilus influenzae Strains in Japan

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