Different regulation of planktonic and epilithic biofilm bacterial production in the middle reaches of a temperate river

Abstract Background Cystic fibrosis (CF) affects >70,000 people worldwide, yet the microbiologic trigger for pulmonary exacerbations (PExs) remains unknown. The objective of this study was to identify changes in bacterial metabolic pathways associated with clinical status. Methods Respiratory samples were collected at hospital admission for PEx, end of intravenous (IV) antibiotic treatment, and follow-up from 27 hospitalized children with CF. Bacterial DNA was extracted and shotgun DNA sequencing was performed. MetaPhlAn2 and HUMAnN2 were used to evaluate bacterial taxonomic and pathway relative abundance, while DESeq2 was used to evaluate differential abundance based on clinical status. Results The mean age of study participants was 10 years; 85% received combination IV antibiotic therapy (beta-lactam plus a second agent). Long-chain fatty acid (LCFA) biosynthesis pathways were upregulated in follow-up samples compared to end of treatment: gondoate (p = 0.012), oleate (p = 0.048), palmitoleate (p = 0.043), and pathways of fatty acid elongation (p = 0.012). Achromobacter xylosoxidans and Escherichia sp. were also more prevalent in follow-up compared to PEx (p < 0.001). Conclusions LCFAs may be associated with persistent infection of opportunistic pathogens. Future studies should more closely investigate the role of LCFA production by lung bacteria in the transition from baseline wellness to PEx in persons with CF. Impact Increased levels of LCFAs are found after IV antibiotic treatment in persons with CF. LCFAs have previously been associated with increased lung inflammation in asthma. This is the first report of LCFAs in the airway of persons with CF. This research provides support that bacterial production of LCFAs may be a contributor to inflammation in persons with CF. Future studies should evaluate LCFAs as predictors of future PExs.

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How Are Greenhouse Gases Coupled Across Seasons in a Large Temperate River with Differential Land Use?

Ecosystems ◽

10.1007/s10021-021-00629-5 ◽

2021 ◽

Author(s):

Lisa Galantini ◽

Jean-François Lapierre ◽

Roxane Maranger

Keyword(s):

Land Use ◽

Greenhouse Gases ◽

Temperate River

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Effects of Tedizolid Phosphate on Survival Outcomes and Suppression of Production of Staphylococcal Toxins in a Rabbit Model of Methicillin-Resistant Staphylococcus aureus Necrotizing Pneumonia

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02734-16 ◽

2017 ◽

Vol 61 (4) ◽

Cited By ~ 6

Author(s):

Vien T. M. Le ◽

Hoan N. Le ◽

Marcos Gabriel Pinheiro ◽

Kenneth J. Hahn ◽

Mary L. Dinh ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Bacterial Production ◽

Protective Efficacy ◽

Survival Rates ◽

Rabbit Model ◽

Rank Test ◽

Necrotizing Pneumonia ◽

Time Curve ◽

Content Type

ABSTRACT The protective efficacy of tedizolid phosphate, a novel oxazolidinone that potently inhibits bacterial protein synthesis, was compared to those of linezolid, vancomycin, and saline in a rabbit model of Staphylococcus aureus necrotizing pneumonia. Tedizolid phosphate was administered to rabbits at 6 mg/kg of body weight intravenously twice daily, which yielded values of the 24-h area under the concentration-time curve approximating those found in humans. The overall survival rate was 83% for rabbits treated with 6 mg/kg tedizolid phosphate twice daily and 83% for those treated with 50 mg/kg linezolid thrice daily (P = 0.66 by the log-rank test versus the results obtained with tedizolid phosphate). These survival rates were significantly greater than the survival rates of 17% for rabbits treated with 30 mg/kg vancomycin twice daily (P = 0.003) and 17% for rabbits treated with saline (P = 0.002). The bacterial count in the lungs of rabbits treated with tedizolid phosphate was significantly decreased compared to that in the lungs of rabbits treated with saline, although it was not significantly different from that in the lungs of rabbits treated with vancomycin or linezolid. The in vivo bacterial production of alpha-toxin and Panton-Valentine leukocidin, two key S. aureus-secreted toxins that play critical roles in the pathogenesis of necrotizing pneumonia, in the lungs of rabbits treated with tedizolid phosphate and linezolid was significantly inhibited compared to that in the lungs of rabbits treated with vancomycin or saline. Taken together, these results indicate that tedizolid phosphate is superior to vancomycin for the treatment of S. aureus necrotizing pneumonia because it inhibits the bacterial production of lung-damaging toxins at the site of infection.

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Estimation of bacterial production in fresh waters by the simultaneous measurement of [35S]Sulphate and D-[3H]glucose uptake in the dark

Canadian Journal of Microbiology ◽

10.1139/m78-156 ◽

1978 ◽

Vol 24 (8) ◽

pp. 939-946 ◽

Cited By ~ 12

Author(s):

P. G. C. Campbell ◽

J. H. Baker

Keyword(s):

Bacterial Production ◽

Membrane Filter ◽

Outer Edge ◽

Size Fractionation ◽

Sulphate Uptake ◽

Uptake Rates ◽

Chalk Stream ◽

Glucose Assimilation ◽

Heterotrophic Production

Sulphate uptake in the dark by phytoplankton constitutes a severe limitation to the determination of bacterial heterotrophic production from sulphate-uptake rates. Consequently a modification to the 35S-method has been developed involving size fractionation to separate the algae from the bacteria. Both the whole water sample and the algae-free filtrate are incubated in the dark with trace quantities of [3H]glucose, whereas the filtrate alone is incubated with 35SO4. The experimental determined ratio (whole sample glucose assimilation: filtrate glucose assimilation) is used to correct the measured sulphate uptake (filtrate) and yields an estimate of bacterial sulphate uptake in the whole sample.A potential filtration artefact has been demonstrated in the 35SO4 uptake methodology. Excision of the outer edge of the membrane filter and counting of the inner wetted circle alone eliminated this problem and significantly improved the analytical performance of the method: coefficient of variation ~ 5%, detection limit ~ 2 ng S ℓ−1 h−1. The modified [35SO4]–[3H]-glucose method was applied to samples from an English chalk stream: bacterial sulphate uptake was higher during the spring diatom maximum (10.6 ng S ℓ−1 h−1) than 3 weeks later when detritus dominated the seston (4.9 ng S ℓ−1 h−1). We estimate the corresponding rates of formation of particulate (bacterial) carbon to be 0.53 and 0.24 μg C ℓ−1 h−1 respectively.

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Horizontal variability and regulation of bacterial production in a large, temperate lake

10.1002/essoar.10504801.1 ◽

2020 ◽

Author(s):

Kenji Tsuchiya ◽

Noriko Tomioka ◽

Kazuhiro Komatsu ◽

Tomoharu Sano ◽

Ayato Kohzu ◽

...

Keyword(s):

Bacterial Production ◽

Temperate Lake

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Dietary cobalt can promote gastrointestinal bacterial production of vitamin B12 in sufficient amounts to supply growth requirements of grouper, Epinephelus malabaricus

Aquaculture ◽

10.1016/j.aquaculture.2010.02.008 ◽

2010 ◽

Vol 302 (1-2) ◽

pp. 89-93 ◽

Cited By ~ 11

Author(s):

Yu-Hung Lin ◽

Jing-Yun Wu ◽

Shi-Yen Shiau

Keyword(s):

Vitamin B12 ◽

Bacterial Production ◽

Growth Requirements ◽

Epinephelus Malabaricus

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Differing Growth Responses of Major Phylogenetic Groups of Marine Bacteria to Natural Phytoplankton Blooms in the Western North Pacific Ocean

Applied and Environmental Microbiology ◽

10.1128/aem.02952-10 ◽

2011 ◽

Vol 77 (12) ◽

pp. 4055-4065 ◽

Cited By ~ 76

Author(s):

Yuya Tada ◽

Akito Taniguchi ◽

Ippei Nagao ◽

Takeshi Miki ◽

Mitsuo Uematsu ◽

...

Keyword(s):

Organic Matter ◽

Bacterial Community ◽

North Pacific ◽

Bacterial Production ◽

Western North Pacific ◽

Bacterial Abundance ◽

North Pacific Ocean ◽

Growth Potential ◽

Phytoplankton Blooms ◽

Content Type

ABSTRACTGrowth and productivity of phytoplankton substantially change organic matter characteristics, which affect bacterial abundance, productivity, and community structure in aquatic ecosystems. We analyzed bacterial community structures and measured activities inside and outside phytoplankton blooms in the western North Pacific Ocean by using bromodeoxyuridine immunocytochemistry and fluorescencein situhybridization (BIC-FISH).Roseobacter/Rhodobacter, SAR11,Betaproteobacteria,Alteromonas, SAR86, andBacteroidetesresponded differently to changes in organic matter supply.Roseobacter/Rhodobacterbacteria remained widespread, active, and proliferating despite large fluctuations in organic matter and chlorophylla(Chl-a) concentrations. The relative contribution ofBacteroidetesto total bacterial production was consistently high. Furthermore, we documented the unexpectedly large contribution ofAlteromonasto total bacterial production in the bloom. Bacterial abundance, productivity, and growth potential (the proportion of growing cells in a population) were significantly correlated with Chl-aand particulate organic carbon concentrations. Canonical correspondence analysis showed that organic matter supply was critical for determining bacterial community structures. The growth potential of each bacterial group as a function of Chl-aconcentration showed a bell-shaped distribution, indicating an optimal organic matter concentration to promote growth. The growth ofAlteromonasandBetaproteobacteriawas especially strongly correlated with organic matter supply. These data elucidate the distinctive ecological role of major bacterial taxa in organic matter cycling during open ocean phytoplankton blooms.

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