Prevalence and Characterization of Shiga-Toxin O157:H7 and Non-O157:H7 EnterohemorrhagicEscherichia ColiIsolated from Different Sources

Human kidney epithelial cells are supposed to be directly involved in the pathogenesis of the hemolytic–uremic syndrome (HUS) caused by Shiga toxin (Stx)-producing enterohemorrhagic Escherichia coli (EHEC). The characterization of the major and minor Stx-binding glycosphingolipids (GSLs) globotriaosylceramide (Gb3Cer) and globotetraosylceramide (Gb4Cer), respectively, of primary human renal cortical epithelial cells (pHRCEpiCs) revealed GSLs with Cer (d18:1, C16:0), Cer (d18:1, C22:0), and Cer (d18:1, C24:1/C24:0) as the dominant lipoforms. Using detergent-resistant membranes (DRMs) and non-DRMs, Gb3Cer and Gb4Cer prevailed in the DRM fractions, suggesting their association with microdomains in the liquid-ordered membrane phase. A preference of Gb3Cer and Gb4Cer endowed with C24:0 fatty acid accompanied by minor monounsaturated C24:1-harboring counterparts was observed in DRMs, whereas the C24:1 fatty acid increased in relation to the saturated equivalents in non-DRMs. A shift of the dominant phospholipid phosphatidylcholine with saturated fatty acids in the DRM to unsaturated species in the non-DRM fractions correlated with the GSL distribution. Cytotoxicity assays gave a moderate susceptibility of pHRCEpiCs to the Stx1a and Stx2a subtypes when compared to highly sensitive Vero-B4 cells. The results indicate that presence of Stx-binding GSLs per se and preferred occurrence in microdomains do not necessarily lead to a high cellular susceptibility towards Stx.

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Characterization of Shiga Toxin‐Producing Escherichia coli Isolated From Cattle and Sheep in Xinjiang Province, China, Using Whole‐Genome Sequencing

Transboundary and Emerging Diseases ◽

10.1111/tbed.13999 ◽

2021 ◽

Author(s):

Yingyu Liu ◽

Huoming Li ◽

Xuhua Chen ◽

Panpan Tong ◽

Yan Zhang ◽

...

Keyword(s):

Escherichia Coli ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Shiga Toxin ◽

Whole Genome ◽

Cattle And Sheep

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Microfluidic Tools for Enhanced Characterization of Therapeutic Stem Cells and Prediction of Their Potential Antimicrobial Secretome

Antibiotics ◽

10.3390/antibiotics10070750 ◽

2021 ◽

Vol 10 (7) ◽

pp. 750

Author(s):

Pasquale Marrazzo ◽

Valeria Pizzuti ◽

Silvia Zia ◽

Azzurra Sargenti ◽

Daniele Gazzola ◽

...

Keyword(s):

Stem Cells ◽

Defense Mechanisms ◽

Live Cells ◽

Label Free ◽

Bacterial Diseases ◽

Prospective Application ◽

Therapy Strategies ◽

Stromal Stem Cells ◽

Different Sources

Antibiotic resistance is creating enormous attention on the development of new antibiotic-free therapy strategies for bacterial diseases. Mesenchymal stromal stem cells (MSCs) are the most promising candidates in current clinical trials and included in several cell-therapy protocols. Together with the well-known immunomodulatory and regenerative potential of the MSC secretome, these cells have shown direct and indirect anti-bacterial effects. However, the low reproducibility and standardization of MSCs from different sources are the current limitations prior to the purification of cell-free secreted antimicrobial peptides and exosomes. In order to improve MSC characterization, novel label-free functional tests, evaluating the biophysical properties of the cells, will be advantageous for their cell profiling, population sorting, and quality control. We discuss the potential of emerging microfluidic technologies providing new insights into density, shape, and size of live cells, starting from heterogeneous or 3D cultured samples. The prospective application of these technologies to studying MSC populations may contribute to developing new biopharmaceutical strategies with a view to naturally overcoming bacterial defense mechanisms.

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Whole-genome characterization of hemolytic uremic syndrome-causing Shiga toxin-producing Escherichia coli in Sweden

Virulence ◽

10.1080/21505594.2021.1922010 ◽

2021 ◽

Vol 12 (1) ◽

pp. 1296-1305

Author(s):

Ying Hua ◽

Milan Chromek ◽

Anne Frykman ◽

Cecilia Jernberg ◽

Valya Georgieva ◽

...

Keyword(s):

Escherichia Coli ◽

Hemolytic Uremic Syndrome ◽

Shiga Toxin ◽

Whole Genome ◽

Genome Characterization ◽

Uremic Syndrome

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Characterization of Purified Shiga Toxin fromShigella dysenteriae1

Microbiology and Immunology ◽

10.1111/j.1348-0421.1986.tb03041.x ◽

1986 ◽

Vol 30 (11) ◽

pp. 1115-1127 ◽

Cited By ~ 25

Author(s):

Takashi Yutsudo ◽

Takeshi Honda ◽

Toshio Miwatani ◽

Yoshifumi Takeda

Keyword(s):

Shiga Toxin

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Characterization of shiga toxin-producing Escherichia coli strains isolated from calves in Poland

Comparative Immunology Microbiology and Infectious Diseases ◽

10.1016/s0147-9571(00)00008-4 ◽

2000 ◽

Vol 23 (4) ◽

pp. 267-276 ◽

Cited By ~ 20

Author(s):

Jacek Osek ◽

Peter Gallien ◽

Dieter Protz

Keyword(s):

Escherichia Coli ◽

Shiga Toxin

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Comparative Genomics and Characterization of the Late Promoter pR’ from Shiga Toxin Prophages in Escherichia coli

Viruses ◽

10.3390/v10110595 ◽

2018 ◽

Vol 10 (11) ◽

pp. 595 ◽

Cited By ~ 5

Author(s):

Ling Zhang ◽

David Simpson ◽

Lynn McMullen ◽

Michael Gänzle

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Toxin Production ◽

Late Promoter ◽

Regulatory Systems ◽

Human Illness ◽

Late Transcription ◽

Native Strains ◽

Native Host

Shiga-toxin producing Escherichia coli (STEC) causes human illness ranging from mild diarrhea to death. The bacteriophage encoded stx genes are located in the late transcription region, downstream of the antiterminator Q. The transcription of the stx genes is directly under the control of the late promoter pR’, thus the sequence diversity of the region between Q and stx, here termed the pR’ region, may affect Stx toxin production. Here, we compared the gene structure of the pR’ region and the stx subtypes of nineteen STECs. The sequence alignment and phylogenetic analysis suggested that the pR’ region tends to be more heterogeneous than the promoter itself, even if the prophages harbor the same stx subtype. Furthermore, we established and validated transcriptional fusions of the pR’ region to the DsRed reporter gene using mitomycin C (MMC) induction. Finally, these constructs were transformed into native and non-native strains and examined with flow cytometry. The results showed that induction levels changed when pR’ regions were placed under different regulatory systems. Moreover, not every stx gene could be induced in its native host bacteria. In addition to the functional genes, the diversity of the pR’ region plays an important role in determining the level of toxin induction.

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Geochemical and Petrological Characterization of Ash Samples from Cascade Range Volcanoes

Quaternary Research ◽

10.1016/0033-5894(71)90046-9 ◽

1971 ◽

Vol 1 (2) ◽

pp. 261-282 ◽

Cited By ~ 24

Author(s):

Keith Randle ◽

Gordon G. Goles ◽

Laurence R. Kittleman

Keyword(s):

Pacific Northwest ◽

Volcanic Ash ◽

Cascade Range ◽

Crystalline Material ◽

Refractive Indices ◽

Crystalline Materials ◽

The Pacific ◽

Volcanic Ashes ◽

Different Sources

Twenty-nine samples of volcanic ash from the Pacific Northwest were analyzed by instrumental neutron activation techniques, with the aim of distinguishing among ashes from different sources. Preliminary results of petrographic studies of 42 ash or pumice samples are also reported. Geochemical characteristics of Mazama ash are defined, and problems induced by winnowing of crystalline material during transport and by weathering are discussed. Contents of La, Th, and Co, and La/Yb ratios are shown to be good discriminants. Data on refractive indices and on proportions of crystalline materials also aid in distinguishing among the various volcanic ashes studied. Ash and pumice found in archaeological contexts at Fort Rock Cave, Paisley Cave, Wildcat Canyon, and Hobo Cave are all from Mount Mazama, presumably from the culminating cruption of 7000 years ago.

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