Partial characterization of a cubic Bacillus phage

1978 ◽  
Vol 24 (8) ◽  
pp. 986-993 ◽  
Author(s):  
H.-W. Ackermann ◽  
R. Roy ◽  
M. Martin ◽  
M. R. V. Murthy ◽  
W. A. Smirnoff
Keyword(s):  
Drug Resistance ◽  
Nucleic Acid ◽  
Latent Period ◽  
Burst Size ◽  
Partial Characterization ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Resistance Plasmids ◽  
Bacillus Phage

Phage Bam35 is an icosahedron of about 63 nm in diameter. It has a double capsid with spikes at the vertices, and a tail which seems to appear upon nucleic acid ejection. The phage contains DNA and, probably, lipids which seem to be located in the inner coat. The phage is Bacillus-specific, UV- and lipase-resistant, and sensitive to heat, chloroform, and ether. The latent period is 50 min and the burst size is 39. Phage Bam35 belongs to a new virus group which includes a phage of B. anthracis and four phages of gram-negative bacteria harboring drug-resistance plasmids.

scholarly journals Characterization of Resistance in Gram-Negative Urinary Isolates Using Existing and Novel Indicators of Clinical Relevance: A 10-Year Data Analysis

Life ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 16 ◽  
Author(s):  
Márió Gajdács ◽  
Zoltán Bátori ◽  
Marianna Ábrók ◽  
Andrea Lázár ◽  
Katalin Burián
Keyword(s):  
Drug Resistance ◽  
Bacterial Resistance ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Extensive Drug Resistance ◽  
Acinetobacter Spp ◽  
Tract Infections ◽  
Resistance Data ◽  
Urinary Isolates

Classical resistance classifications (multidrug resistance [MDR], extensive drug resistance [XDR], pan-drug resistance [PDR]) are very useful for epidemiological purposes, however, they may not correlate well with clinical outcomes, therefore, several novel classification criteria (e.g., usual drug resistance [UDR], difficult-to-treat resistance [DTR]) were introduced for Gram-negative bacteria in recent years. Microbiological and resistance data was collected for urinary tract infections (UTIs) retrospectively, corresponding to the 2008.01.01–2017.12.31. period. Isolates were classified into various resistance categories (wild type/susceptible, UDR, MDR, XDR, DTR and PDR), in addition, two new indicators (modified DTR; mDTR and mcDTR) and a predictive composite score (pMAR) were introduced. Results: n = 16,240 (76.8%) outpatient and n = 13,386 (69.3%) inpatient UTI isolates were relevant to our analysis. Citrobacter-Enterobacter-Serratia had the highest level of UDR isolates (88.9%), the Proteus-Providencia-Morganella group had the highest mDTR levels. MDR levels were highest in Acinetobacter spp. (9.7%) and Proteus-Providencia-Morganella (9.1%). XDR- and DTR-levels were higher in non-fermenters (XDR: 1.7%–4.7%. DTR: 7.3%–7.9%) than in Enterobacterales isolates (XDR: 0%–0.1%. DTR: 0.02%–1.5%). Conclusions: The introduction of DTR (and its’ modifications detailed in this study) to the bedside and in clinical practice will definitely lead to substantial benefits in the assessment of the significance of bacterial resistance in human therapeutics.

Partial characterization of a new C3-type capsule-dissolving phage of Streptococcus cremoris

1979 ◽  
Vol 25 (10) ◽  
pp. 1182-1187 ◽  
Author(s):  
Maija-Liisa Saxelin ◽  
Eeva-Liisa Nurmiaho ◽  
M. P. Korhola ◽  
Veronica Sundman
Keyword(s):  
Latent Period ◽  
Burst Size ◽  
Buoyant Density ◽  
Partial Characterization ◽  
Milk Product ◽  
Streptococcus Cremoris ◽  
Sour Milk ◽  
Average Burst Size

A viscous, ropy, sour milk product, called 'viili,' is produced in Finland. Capsule-forming strains of Streptococcus cremoris are the typical starters for this product. Occasionally fermentation fails and results in a non-ropy clot. The reasons for these failures, however, are obscure. In one batch of spoiled 'viili,' a new C3-type bacteriophage, termed KSY1, was isolated. The head of the phage was about 230 nm long and about 50 nm wide and the tail was 35 nm long and carried a complex collar structure. Upon infection of a number of encapsulated cultures of S. cremoris with KSY1, the cocci, though not serving as a host of the phage, lost their capsules. A capsuleless strain, S. cremoris 249, served as a host. The latent period was about 150 min and the average burst size 80. The buoyant density of KSY1 was 1.436 g/cm3.

Electrophysiological Characterization of Transport Across Outer Membrane Channels from Gram-Negative Bacteria in Their Native Environment

2019 ◽  
Author(s):  
Jiajun Wang ◽  
Rémi Terrasse ◽  
Jayesh Arun Bafna ◽  
Lorraine Benier ◽  
Mathias Winterhalter
Keyword(s):  
Outer Membrane ◽  
Lipid Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Membrane Channels ◽  
Gram Negative ◽  
Electrophysiological Characterization

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from <i>Escherichia coli</i>, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (<i>k<sub>on</sub></i>) and lower dissociation (<i>k<sub>off</sub></i>) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.

scholarly journals Discovery and Characterization of the Antimetabolite Action of Thioacetamide-Linked 1,2,3-Triazoles as Disruptors of Cysteine Biosynthesis in Gram-Negative Bacteria

2019 ◽  
Vol 6 (3) ◽  
pp. 467-478 ◽  
Author(s):  
Miranda J. Wallace ◽  
Suresh Dharuman ◽  
Dinesh M. Fernando ◽  
Stephanie M. Reeve ◽  
Clifford T. Gee ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Cysteine Biosynthesis ◽  
Gram Negative

Protein expression and extraction of hard-to-produce proteins in the periplasmic space of Escherichia coli v1

2021 ◽  
Author(s):  
Cristina Hernandez Rollan ◽  
Kristoffer Bach Falkenberg ◽  
Maja Rennig ◽  
Andreas Birk Bertelsen ◽  
Morten Norholm
Keyword(s):  
Protein Production ◽  
Expression System ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
New Family ◽  
Lytic Polysaccharide Monooxygenases ◽  
Strain Bl21 ◽  
Polysaccharide Monooxygenases

E. coli is a gram-negative bacteria used mainly in academia and in some industrial scenarios, as a protein production workhorse. This is due to its ease of manipulation and the range of genetic tools available. This protocol describes how to express proteins in the periplasm E. coli with the strain BL21 (DE3) using a T7 expression system. Specifically, it describes a series of steps and tips to express "hard-to-express" proteins in E. coli, as for instance, LPMOs. The protocol is adapted from Hemsworth, G. R., Henrissat, B., Davies, G. J., and Walton, P. H. (2014) Discovery and characterization of a new family of lytic polysaccharide monooxygenases. Nat. Chem. Biol.10, 122–126. .

scholarly journals SKRENING BAKTERI TOLERAN PESTISIDA DENGAN BAHAN AKTIF KLORANTRANILIPROL ASAL TANAH PERTANIAN BATURITI TABANAN BALI

2017 ◽  
Vol 21 (1) ◽  
pp. 1
Author(s):  
NI KADEK WIWIK SINTA DEWI ◽  
IDA BAGUS GEDE DARMAYASA ◽  
I KETUT SUNDRA
Keyword(s):  
Large Scale ◽  
Chemical Compounds ◽  
Mineral Medium ◽  
Gram Negative Bacteria ◽  
Soil Mineral ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Numerous Problem ◽  
Stage 1

In Indonesia agriculture practice often used the large scale pesticide application such as insecticide, herbicide, and fungicide. The wide use of toxic pesticide has created numerous problem in increasing environtmental hazard to human and to other animals. Many of soil bacteria had important role to degrading chemical compounds into simpler compounds as a bioremediation agent. The aim of this study was to screen the Chlorantraniliprole tolerant bacteria using soil mineral medium with Prevathon pesticide addition, also teo identificate the species of bacteria. This research was conducted at Microbiology Laboratory, Faculty of Mathematics and Natural Sciences, Udayana University. The research was done in three analysis, (1) bacteria test on Prevathon pesticide addition to mineral medium treatment, (2) characterization of bacteria, (3) Identification of pesticide tolerant bacteria with BD BBL Crystal Enteric/Non FermenterID Kit. The results showed that mineral medium with the addition of pesticides Prevathon treatment able to provide a significant different effect on the enrichment stage 1, stage 2 and stage 3 (P<0.05), there was 5 isolates pesticide tolerant bacteria that isolated from Baturiti Tabanan cultivated soil that was BSP 1, BSP 2, BSP 3 known as gram negative bacteria, and BSP 4, BSP 5 known as Gram positive bacteria, pesticide tolerant bacteria identified as Serratia marcescens which is a Gram negative bacteria group and may cause pathogenic.

Drug resistance patterns of Gram-negative bacteria isolated from food and non-sterile medicines in hospital environments

1981 ◽  
Vol 2 ◽  
pp. 355-361
Author(s):  
M.D. Simon-Pujol ◽  
M. Matabosch ◽  
M.J. Espuny-Tomas ◽  
A.M. Marques ◽  
F. Congregado
Keyword(s):  
Drug Resistance ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Hospital Environments ◽  
Resistance Patterns

scholarly journals Characterization of Certain Gram-Negative Bacteria from Surface Waters1

1965 ◽  
Vol 13 (4) ◽  
pp. 575-578 ◽  
Author(s):  
A. W. Hoadley ◽  
Elizabeth McCoy
Keyword(s):  
Gram Negative Bacteria ◽  
Gram Negative

scholarly journals A g-Type Lysozyme from Deep-Sea Hydrothermal Vent Shrimp Kills Selectively Gram-Negative Bacteria

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7624
Author(s):  
Jing-Chang Luo ◽  
Jian Zhang ◽  
Li Sun
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
Binding Capacity ◽  
Cellular Membrane ◽  
Structural Features ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bacterial Binding ◽  
Muramidase Activity

Lysozyme is a key effector molecule of the innate immune system in both vertebrate and invertebrate. It is classified into six types, one of which is the goose-type (g-type). To date, no study on g-type lysozyme in crustacean has been documented. Here, we report the identification and characterization of a g-type lysozyme (named LysG1) from the shrimp inhabiting a deep-sea hydrothermal vent in Manus Basin. LysG1 possesses conserved structural features of g-type lysozymes. The recombinant LysG1 (rLysG1) exhibited no muramidase activity and killed selectively Gram-negative bacteria in a manner that depended on temperature, pH, and metal ions. rLysG1 bound target bacteria via interaction with bacterial cell wall components, notably lipopolysaccharide (LPS), and induced cellular membrane permeabilization, which eventually caused cell lysis. The endotoxin-binding capacity enabled rLysG1 to alleviate the inflammatory response induced by LPS. Mutation analysis showed that the bacterial binding and killing activities of rLysG1 required the integrity of the conserved α3 and 4 helixes of the protein. Together, these results provide the first insight into the activity and working mechanism of g-type lysozyme in crustacean and deep-sea organisms.

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