Comparison of Methods for Isolation of Anaerobic Bacteria from Clinical Specimens

Rosenblatt, Jon E.; Fallon, Ann M.; Finegold, Sydney M.

doi:10.1128/aem.25.1.77-85.1973

Cited by 47 publications

(22 citation statements)

References 7 publications

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“…Nitrifying bacteria were isolated in liquid Watson and Mendel’s media and incubation for 20 days [22]. Denitrifying bacteria were isolated using Gil’tai’s medium (pH 6.8 – 7.2) in an inert argon atmosphere using a Hangeit-like technique [24] at 24°C for 5 days, with viable numbers determined using the most probable number method [25] with 3-tube variation [26]. Denitrifying bacteria were identified based on medium alkalinisation, increasing optical density, gas production, and the absence of nitrate.…”

Section: Methodsmentioning

confidence: 99%

Priming winter wheat seeds with the bacterial quorum sensing signal N-hexanoyl-L-homoserine lactone (C6-HSL) shows potential to improve plant growth and seed yield

Moshynets

Бабенко

Rogalsky

et al. 2018

Preprint

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250 / 300 words) 28 Several model plants are known to respond to bacterial quorum sensing molecules with altered root growth 29 and gene expression patterns and induced resistance to plant pathogens. These compounds may represent 30 novel elicitors that could be applied as seed primers to enhance cereal crop resistance to pathogens and 31 abiotic stress and to improve yields. We investigated whether the acyl-homoserine lactone N-hexanoyl-L-32 homoserine lactone (C6-HSL) impacted winter wheat (Triticum aestivum L.) seed germination, plant 33 development and productivity, using two Ukrainian varieties, Volodarka and Yatran 60, in both in vitro 34 experiments and field trials. In vitro germination experiments indicated that C6-HSL seed priming had a small 35 but significant positive impact on germination levels (1.2x increase, p < 0.0001), coleoptile and radicle 36 development (1.4x increase, p < 0.0001). Field trials over two growing seasons (2015-16 and 2016-17) also 37 demonstrated significant improvements in biomass at the tillering stage (1.4x increase, p < 0.0001), and crop 38 structure and productivity at maturity including grain yield (1.4 -1.5x increase, p < 0.0007) and quality (1.3x 39 increase in good grain, p < 0.0001). In some cases variety effects were observed (p ≤ 0.05) suggesting that 40 the effect of C6-HSL seed priming might depend on plant genetics, and some benefits of priming were also 41 evident in F1 plants grown from seeds collected the previous season (p ≤ 0.05). These field-scale findings 42 suggest that bacterial acyl-homoserine lactones such as C6-HSL could be used to improve cereal crop growth 43 and yield and reduce reliance on fungicides and fertilisers to combat pathogens and stress. 44 Keywords: crop productivity, N-acyl-L-homoserine lactone, quorum sensing, plant-microbial interactions, 45 phyto-protection, phyto-stimulation, seed priming, winter wheat.46 47

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Section: Methodsmentioning

confidence: 99%

Priming winter wheat seeds with the bacterial quorum sensing signal N-hexanoyl-L-homoserine lactone (C6-HSL) shows potential to improve plant growth and seed yield

Moshynets

Бабенко

Rogalsky

et al. 2018

Preprint

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“…Most of the microorganisms in the human intestinal tract are highly oxygen-sensitive anaerobes (29,35). Duncan et al (36) reported that Roseburia intestinalis strains, butyrate-producing anaerobic bacteria from human feces, all failed to grow after a minimum exposure time of 2 min to air, whereas these same strains maintained continuously under anaerobic conditions showed good growth.…”

Section: Anaerobic Conditionsmentioning

confidence: 99%

Membrane filter method to study the effects of Lactobacillus acidophilus and Bifidobacterium longum on fecal microbiota

Shimizu

Benno

2015

Microbiology and Immunology

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A large number of commensal bacteria inhabit the intestinal tract, and interbacterial communication among gut microbiota is thought to occur. In order to analyze symbiotic relationships between probiotic strains and the gut microbiota, a ring with a membrane filter fitted to the bottom was used for in vitro investigations. Test strains comprising probiotic nitto strains (Lactobacillus acidophilus NT and Bifidobacterium longum NT) and type strains (L. acidophilus JCM1132T and B. longum JCM1217T) were obtained from diluted fecal samples using the membrane filter to simulate interbacterial communication. Bifidobacterium spp., Streptococcus pasteurianus, Collinsella aerofaciens, and Clostridium spp. were the most abundant gut bacteria detected before coculture with the test strains. Results of the coculture experiments indicated that the test strains significantly promote the growth of Ruminococcus gnavus, Ruminococcus torques, and Veillonella spp. and inhibit the growth of Sutterella wadsworthensis. Differences in the relative abundances of gut bacterial strains were furthermore observed after coculture of the fecal samples with each test strain. Bifidobacterium spp., which was detected as the dominant strain in the fecal samples, was found to be unaffected by coculture with the test strains. In the present study, interbacterial communication using bacterial metabolites between the test strains and the gut microbiota was demonstrated by the coculture technique. The detailed mechanisms and effects of the complex interbacterial communications that occur among the gut microbiota are, however, still unclear. Further investigation of these relationships by coculture of several fecal samples with probiotic strains is urgently required.

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“…Bacterial uptake by PMNL was quantitatively measured by a modification of a previously described method (32). Initial experiments were performed in an anerobic glove box (model AL 318; Coy Laboratory Products, Inc., Ann Arbor, Mich.) (28). However, it was determined that all four Bacteroides species studied were aerotolerant, and as described by others (4,16), that similar results were obtained when osponization and phagocytosis were performed in an aerobic environment.…”

Section: Methodsmentioning

confidence: 98%

Opsonization of Four Bacteroides Species: Role of the Classical Complement Pathway and Immunoglobulin

et al. 1980

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Previous investigators have suggested that opsonization of two Bacteroides species is mediated exclusively by the alternative complement pathway and requires immunoglobulins. In this study, the nature of the opsonic factors in nonimmune human serum for four species of Bacteroides was investigated by measuring uptake of [3H]thymidine-labeled bacteria by human polymorphonuclear leukocytes. Normal human serum, C2-deficient serum, immunoglobulindeficient serum, and serum chelated with ethylene glycol-bis(,f-aminoethyl ether)-N,N-tetraacetic acid (EGTA), MgEGTA, and ethylenediaminetetraacetic acid (EDTA) were used as opsonic sources. Heat inactivation of each of these sera significantly reduced its opsonic activity for all four Bacteroides species, suggesting that serum complement was essential for effective opsonization. All strains were opsonized in the absence of the classical complement pathway; however, kinetics studies revealed that opsonization proceeded at a significantly faster rate when the classical complement pathway was intact. Although two strains were opsonized in immunoglobulin-deficient sera, opsonization was less efficient and appeared to occur via the alternative complement pathway. Unexpectedly, all strains were well opsonized by the classical complement pathway in 10% serum which had been effectively chelated with EGTA or EDTA. The explanation for this finding is unknown; however, it is possible that cell wall cations of Bacteroides species may participate in the activation of complement in chelated serum, resulting in effective opsonization. It was also found that Bacteroides, when incubated with an Escherichia coli strain in normal serum, could compete for opsonins and thereby reduce phagocytosis ofE. coli. It is possible that competition for opsonins among bacterial species contributes to the synergistic role these organisms share in mixed floral infections. An effective osponic source including complement or immunoglobulin is required to prepare bacteria for maximal phagocytosis by polymorphonuclear leukocytes (PMNL). Anderson et al.(1) have shown that encapsulated strains of Haemophilus influenzae are opsonized in immune serum by the classical complement pathway, whereas Quinn and co-workers (26) found that these same strains were opsonized by the alternative complement pathway in nonimmune serum. Other investigators (31, 34) have shown that several bacterial species can be opsonized by the complement system in the relative absence of immunoglobulin. In contrast to unencapsulated organisms, encapsulated bacteria appear to require specific antibodies for optimal opsonization (3, 24).Casciato et al. (4) were the first to study opsonization and phagocytosis of Bacteroides species. They demonstrated that B. thetaiotaomicron could be opsonized only by heat-la-bile serum opsonic factors and that phagocytosis by PMNL occurred equally well under anaerobic and aerobic conditions. Recently, Bjornson and Bjornson (2) studied two species of Bacteroides and concluded that optimal opsonization required bot...

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Comparison of Methods for Isolation of Anaerobic Bacteria from Clinical Specimens

Cited by 47 publications

References 7 publications

Priming winter wheat seeds with the bacterial quorum sensing signal N-hexanoyl-L-homoserine lactone (C6-HSL) shows potential to improve plant growth and seed yield

Priming winter wheat seeds with the bacterial quorum sensing signal N-hexanoyl-L-homoserine lactone (C6-HSL) shows potential to improve plant growth and seed yield

Membrane filter method to study the effects of Lactobacillus acidophilus and Bifidobacterium longum on fecal microbiota

Opsonization of Four Bacteroides Species: Role of the Classical Complement Pathway and Immunoglobulin

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