Detection of Microbial Cells in Aerosols Using Nucleic Acid Probes

Neef, Alexander; Amann, Rudolf; Schleifer, Karl‐Heinz

doi:10.1016/s0723-2020(11)80458-3

Cited by 34 publications

(17 citation statements)

References 30 publications

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“…Viable, as well as nonviable, cells may contain valinomycin. Counting of viable airborne bacteria is believed to underestimate the aerosolized cell count by factors of up to 10 2 to 10 3 (2,20). Therefore, the load of airborne valinomycin may reach levels of 0.1 ng m Ϫ3 , which means 1 to 2.5 ng of valinomycin respired per occupant per day.…”

Section: Discussionmentioning

confidence: 99%

Inhibition of Human NK Cell Function by Valinomycin, a Toxin fromStreptomyces griseusin Indoor Air

Paananen¹,

Mikkola

Sareneva

et al. 2000

Infect Immun

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Streptomyces griseus strains isolated from indoor dust have been shown to synthesize valinomycin. In this report, we show that human peripheral blood lymphocytes treated with small doses (30 ng ml ؊1 ) of pure valinomycin or high-pressure liquid chromatography-pure valinomycin from S. griseus quickly show mitochondrial swelling and reduced NK cell activity. Larger doses (>100 ng/ml ؊1 ) induced NK cell apoptosis within 2 days. Within 2 h, the toxin at 100 ng ml ؊1 dramatically inhibited interleukin-15 (IL-15)-and IL-18-induced granulocyte-macrophage colony-stimulating factor and gamma interferon (IFN-␥) production by NK cells. However, IFN-␥ production induced by a combination of IL-15 and IL-18 was somewhat less sensitive to valinomycin, suggesting a protective effect of the cytokine combination against valinomycin. Thus, valinomycin in very small doses may profoundly alter the immune response by reducing NK cell cytotoxicity and cytokine production.Human peripheral blood lymphocytes (PBL) contain 5 to 20% NK cells, which can lyse certain tumor and normal cell lines without prior immunization. Upon activation, NK cells secrete cytokines such as gamma interferon (IFN-␥), tumor necrosis factor alpha, granulocyte-macrophage colony-stimulating factor (GM-CSF), and macrophage colony-stimulating factor (7,15,24). NK cells are thought to represent the first line defense in the immune system since they kill abnormal cells and simultaneously secrete cytokines to activate the other arms of the immune response.Interleukin-15 (IL-15) and IL-18 are cytokines which regulate NK cell function. IL-15 is required for NK cell maturation, and IL-18 is essential for NK cell activity (16,29). Valinomycin is an ionophore which is a cyclic-polypeptide-like dodecadepsipeptide whose folded conformation forms an inner cavity that can accommodate K ϩ but not other ions. For that reason, valinomycin is involved in a selective transport of K ϩ ions across the inner membrane of mitochondria (11,12). In rat ascites hepatoma cells, valinomycin induces apoptosis by disrupting the membrane potential of mitochondria and, when used at higher concentrations, causes apoptosis in many mammalian cell types (1, 10, 14, 21, 34). Andersson et al. (3) isolated Streptomyces griseus strains that produce valinomycin from an indoor environment. In schools and children's day care centers with dampness damage, such Streptomyces strains were frequently encountered (26).Here we report that pure commercial valinomycin and highpressure liquid chromatography (HPLC)-pure valinomycin from S. griseus inhibit human NK activity and cytokine production and induce apoptosis of NK cells at doses 10 to 500 times lower than those previously used. Thus, a toxin derived from bacteria that are abundant in the environment has the potential to cause immune suppression. MATERIALS AND METHODSCell isolation and culture. Leukocyte-rich buffy coats were obtained from healthy blood donors (Finnish Red Cross Blood Transfusion Service, Helsinki, Finland). PBL were isolated by Ficoll-Paque...

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Section: Discussionmentioning

confidence: 99%

Inhibition of Human NK Cell Function by Valinomycin, a Toxin fromStreptomyces griseusin Indoor Air

Paananen¹,

Mikkola

Sareneva

et al. 2000

Infect Immun

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“…Its occasional appearance here is explained by the anatomically close perianal region. To estimate the occurrence of adherent vaginal E.coli biofilms in the general population, we reinvestigated 160 Carnoy fixated vaginal biopsies from earlier studies including women with BV and controls [5]. E.coli diffusely adhered to the vaginal epithelium in concentrations of 10 5-6 bacteria/ml in two of 160 vaginal biopsies.…”

Section: Discussionmentioning

confidence: 99%

Positive effects of local therapy with a vaginal lactic acid gel on dysuria and E.coli bacteriuria question our current views on recurrent cystitis

Swidsinski

Loening‐Baucke

Mendling

et al. 2012

Arch Gynecol Obstet

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Objective We tested the effect of vaginally applied lactic acid gel on symptoms and bacteriuria in acutely exacerbated recurrent Eschericia coli cystitis. Methods Carnoy fixed samples of the morning urine from 20 women with a history of recurrent E.coli cystitis were prospectively investigated for bacteriuria using fluorescence in situ hybridization (FISH). Results In 11/20 women with acute cystitis, the symptoms and bacteriuria were regressive with lactic acid gel treatment, without the need for antibiotic treatment. The complete regression of symptoms took between 1 week (7 women) and 4 weeks (4 women). In parallel with this regression, the microscopic shape of E.coli bacteria in these women changed from short rods to long curly filaments starting within the first days of therapy. The filamentous transformation affected 100% of the E.coli population in six women and at least 50% of E.coli population in five women and was not observed in urine samples from untreated women or in women without clinical response to lactic acid gel. This could not happen if the bladder was the origin of the infection. Conclusions A number of recurrent and probably acute cystitis is a local vagino-urethritis caused by an adhesive invasive E.coli biofilm of the vaginal surface.

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“…37 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 oligonucleotide probes were performed in the hybridization buffer (0.9 M NaCl, 20 mM Tris-HCl, 0.01% SDS and 40% formamide) at 46 °C for 2 hours. Probe ECO45A which targeted 23S rRNA of E. coli was 5'-labeled with Cy5 fluorescence 39 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 11 formate firstly increased during the MFC discharge, but significantly dropped at the end of the discharge. This observation suggests that formate is the electron donor for S. oneidensis provided by E. coli,...…”

Section: Methodsmentioning

confidence: 99%

“…Fluorescence in situ hybridization (FISH) and 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 confocal laser scanning microscopy (CLSM) images of "A4+CP" (d) and "WT+WT" (c) were compared. Fluorescent rRNA oligonucleotide probes were used to differentiate E. coli (ECO45A which targeted E. coli 23S rRNA was 5'-labeled with Cy5 fluorescence 39 , red) and S. oneidensis (SHEW227 which targeted 16s rRNA of genus Shewanella was labelled with FITC fluorescence 40 , green) cells. Aggregates of E. coli and S. oneidensis showed yellow color.…”

Section: Supporting Informationmentioning

confidence: 99%

Engineering Electrode-Attached Microbial Consortia for High-Performance Xylose-Fed Microbial Fuel Cell

Yang

et al. 2015

ACS Catal.

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Microbial fuel cell (MFC) is a promising technology for energy harvesting from biomass, however, reported MFCs with wild-type or biologically modified exoelectrogenic bacteria such as Shewanella oneidensis often exhibited poor performance in generating electricity from sugars. Herein, a synthetic fermenter-exoelectrogen (Escherichia coli-S. oneidensis) microbial consortium was developed to expand the spectrum of carbon sources for MFC through establishing a highly electroactive anodic biofilm by rationally tuning its microbial community profile to favor efficient electron transfer. Specifically, a synthetic riboflavin pathway from Bacillus subtilis was incorporated into E. coli to overproduce flavins to facilitate flavin-mediated electron transfer, and a highly hydrophobic S. oneidensis strain CP2-1-S1 was adopted as the exoelectrogen to increase its adhesion to the carbon electrode. The highly hydrophobic interactions between S. oneidensis and the anode along with the overproduced flavins (increased from 3.3 µM to 115.2 µM) by the recombinant E. coli provided a definite advantage for S. oneidensis over E. coli in the attachment to the anode surface. Compared with the structure of the wild-type community immobilized on the anode, the cell number of S. oneidensis increased by ~3 times, while the cell number of E. coli decreased by 93.3% in the engineered electrode-attached community. Such rationally engineered anodic biofilm with the tuned microbial community profile (the percentage of S.oneidensis cells in the anodic biofilm increased from 48.2% to 98.2%) showed a much higher catalytic current (from 0.19 to 1.84 A/m 2 at 0 V vs. SHE). The xylose-fed MFC inoculated with our engineered microbial consortium generated a maximum power density of 728.6 mW/m 2 , which was 6.8 times higher than that inoculated with wild-type co-culture (92.8 mW/m 2 ).

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Detection of Microbial Cells in Aerosols Using Nucleic Acid Probes

Cited by 34 publications

References 30 publications

Inhibition of Human NK Cell Function by Valinomycin, a Toxin fromStreptomyces griseusin Indoor Air

Inhibition of Human NK Cell Function by Valinomycin, a Toxin fromStreptomyces griseusin Indoor Air

Positive effects of local therapy with a vaginal lactic acid gel on dysuria and E.coli bacteriuria question our current views on recurrent cystitis

Engineering Electrode-Attached Microbial Consortia for High-Performance Xylose-Fed Microbial Fuel Cell

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