scholarly journals Mimicking prophage induction in the body: induction in the lab with pH gradients

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9718
Author(s):  
Taylor Miller-Ensminger ◽  
Andrea Garretto ◽  
Nicole Stark ◽  
Catherine Putonti
Keyword(s):  
Community Dynamics ◽  
The Body ◽  
Lytic Cycle ◽  
Induction Method ◽  
Prophage Induction ◽  
Ph Gradients ◽  
E Coli ◽  
Human Microbiota ◽  
Urinary Tract Symptoms ◽  
Effects Of Ph

The majority of bacteria within the human body are lysogens, often harboring multiple bacteriophage sequences (prophages) within their genomes. While several different types of environmental stresses can trigger or induce prophages to enter into the lytic cycle, they have yet to be fully explored and understood in the human microbiota. In the laboratory, the most common induction method is the DNA damaging chemical Mitomycin C. Although pH has been listed in the literature as an induction method, it is not widely used. Here, we detail a protocol for prophage induction by culture under different pH conditions. We explored the effects of pH on prophage induction in bacterial isolates from the bladder, where the pH is well documented to vary significantly between individuals as well as between healthy individuals and individuals with urinary tract symptoms or disease. Using this protocol, we successfully induced phages from seven bladder E. coli strains. Testing conditions and stressors appropriate to the environment from which a lysogen is isolated may provide insight into community dynamics of the human microbiota.

Effect of ozone on prophage induction in different strains of Escherichia coli K-12 lysogenic for lambda

1984 ◽  
Vol 26 (6) ◽  
pp. 706-709 ◽  
Author(s):  
Pierre L'Hérault ◽  
Young Sup Chung
Keyword(s):  
Escherichia Coli ◽  
Ultraviolet Light ◽  
Lytic Cycle ◽  
Prophage Induction ◽  
E Coli ◽  
Different Strains ◽  
K 12 ◽  
Lambda Prophage

Ozone was tested for its effect upon induction of lambda prophage in two different strains of Escherichia coli K-12. Based on the induction index and when compared to ultraviolet light, ozone appeared to be a weak, if any at all, inducer of the lytic cycle in E. coli. This is in agreement with other studies which have suggested that this agent is a weak inducer of the SOS functions.Key words: SOS functions, ultraviolet light, mutagen, ozone.

scholarly journals Acyl-Homoserine Lactones Can Induce Virus Production in Lysogenic Bacteria: an Alternative Paradigm for Prophage Induction

2009 ◽  
Vol 75 (22) ◽  
pp. 7142-7152 ◽  
Author(s):  
Dhritiman Ghosh ◽  
Krishnakali Roy ◽  
Kurt E. Williamson ◽  
Sharath Srinivasiah ◽  
K. Eric Wommack ◽  
...  
Keyword(s):  
Virus Production ◽  
Lytic Cycle ◽  
Prophage Induction ◽  
Homoserine Lactones ◽  
E Coli ◽  
Acyl Homoserine Lactones ◽  
Induction Process ◽  
Phage Production ◽  
Viral Reproduction

ABSTRACT Prophage typically are induced to a lytic cycle under stressful environmental conditions or when the host's survival is threatened. However, stress-independent, spontaneous induction also occurs in nature and may be cell density dependent, but the in vivo signal(s) that can trigger induction is unknown. In the present study, we report that acyl-homoserine lactones (AHL), the essential signaling molecules of quorum sensing in many gram-negative bacteria, can trigger phage production in soil and groundwater bacteria. This phenomenon also was operative in a λ lysogen of Escherichia coli. In model coculture systems, we monitored the real-time AHL production from Pseudomonas aeruginosa PAO1 using an AHL bioluminescent sensor and demonstrated that λ-prophage induction in E. coli was correlated with AHL production. As a working model in E. coli, we show that the induction responses of λ with AHL remained unaffected when recA was deleted, suggesting that this mechanism does not involve an SOS response. In the same λ lysogen we also demonstrated that sdiA, the AHL receptor, and rcsA, a positive transcriptional regulator of exopolysaccharide synthesis, are involved in the AHL-mediated induction process. These findings relate viral reproduction to chemical signals associated with high host cell abundance, suggesting an alternative paradigm for prophage induction.

scholarly journals Human Microbiota-Secreted Factors Inhibit Shiga Toxin Synthesis by Enterohemorrhagic Escherichia coli O157:H7

2008 ◽  
Vol 77 (2) ◽  
pp. 783-790 ◽  
Author(s):  
Thibaut de Sablet ◽  
Christophe Chassard ◽  
Annick Bernalier-Donadille ◽  
Marjolaine Vareille ◽  
Alain P. Gobert ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factor ◽  
Shiga Toxin ◽  
Enterohemorrhagic Escherichia Coli ◽  
Lytic Cycle ◽  
E Coli ◽  
Human Microbiota ◽  
Shiga Toxin 2 ◽  
Uremic Syndrome ◽  
Serious Disease

ABSTRACT Escherichia coli O157:H7 is a food-borne pathogen causing hemorrhagic colitis and hemolytic-uremic syndrome, especially in children. The main virulence factor responsible for the more serious disease is the Shiga toxin 2 (Stx2), which is released in the gut after oral ingestion of the organism. Although it is accepted that the amount of Stx2 produced by E. coli O157:H7 in the gut is critical for the development of disease, the eukaryotic or prokaryotic gut factors that modulate Stx2 synthesis are largely unknown. In this study, we examined the influence of prokaryotic molecules released by a complex human microbiota on Stx2 synthesis by E. coli O157:H7. Stx2 synthesis was assessed after growth of E. coli O157:H7 in cecal contents of gnotobiotic rats colonized with human microbiota or in conditioned medium having supported the growth of complex human microbiota. Extracellular prokaryotic molecules produced by the commensal microbiota repress stx 2 mRNA expression and Stx2 production by inhibiting the spontaneous and induced lytic cycle mediated by RecA. These molecules, with a molecular mass of below 3 kDa, are produced in part by Bacteroides thetaiotaomicron, a predominant species of the normal human intestinal microbiota. The microbiota-induced stx 2 repression is independent of the known quorum-sensing pathways described in E. coli O157:H7 involving SdiA, QseA, QseC, or autoinducer 3. Our findings demonstrate for the first time the regulatory activity of a soluble factor produced by the complex human digestive microbiota on a bacterial virulence factor in a physiologically relevant context.

Preparation of bioactive and antibacterial PMMA-based bone cement by modification with quaternary ammonium and alkoxysilane

2021 ◽  
pp. 088532822110044
Author(s):  
Haiyang Wang ◽  
Toshinari Maeda ◽  
Toshiki Miyazaki
Keyword(s):  
Antibacterial Activity ◽  
Methyl Methacrylate ◽  
Bone Cement ◽  
Setting Time ◽  
Antibacterial Properties ◽  
The Body ◽  
Apatite Formation ◽  
Gram Positive ◽  
E Coli ◽  
Gram Positive Bacteria

Bone cement based on poly(methyl methacrylate) (PMMA) powder and methyl methacrylate (MMA) liquid is a very popular biomaterial used for the fixation of artificial joints. However, there is a risk of this cement loosening from bone because of a lack of bone-bonding bioactivity. Apatite formation in the body environment is a prerequisite for cement bioactivity. Additionally, suppression of infection during implantation is required for bone cements to be successfully introduced into the human body. In this study, we modified PMMA cement with γ-methacryloxypropyltrimetoxysilane and calcium acetate to introduce bioactive properties and 2-( tert-butylamino)ethyl methacrylate (TBAEMA) to provide antibacterial properties. The long-term antibacterial activity is attributed to the copolymerization of TBAEMA and MMA. As the TBAEMA content increased, the setting time increased and the compressive strength decreased. After soaking in simulated body fluid, an apatite layer was detected within 7 days, irrespective of the TBAEMA content. The cement showed better antibacterial activity against Gram-negative E. Coli than Gram-positive bacteria; however, of the Gram-positive bacteria investigated, B. subtilis was more susceptible than S. aureus.

scholarly journals Evaluation of antipyretic activity of hydroalcoholic extract of Corchorus depressus Linn. in Escherichia coli–induced pyretic rabbits

2018 ◽  
Vol 16 ◽  
pp. 205873921879295
Author(s):  
Saeed Ahmad ◽  
Muhammad Akram ◽  
Syed Muhammad Ali Shah ◽  
Sabira Sultana
Keyword(s):  
Escherichia Coli ◽  
Positive Control ◽  
Negative Control ◽  
The Body ◽  
Hydroalcoholic Extract ◽  
Antipyretic Effect ◽  
E Coli ◽  
Antipyretic Activity ◽  
Experimental Treatments

This study was conducted to investigate the antipyretic effect of the hydroalcoholic extract of Corchorus depressus Linn. against Escherichia coli ( E. coli)-induced pyrexia in rabbits. Hydroalcohalic extracts of C. depressus were given orally at 25, 50, and 100 mg/kg for antipyretic affect in E. coli-induced fever in rabbits. The animals were divided into five groups of five each. Among these five groups, three received various doses of experimental treatments, whereas the fourth one served as positive control and received paracetamol. The fifth group of animals served as negative control and received no treatment. The body temperature of the rabbits was measured rectally over a period of 5 h. C. depressus exhibited better effects at dose rate of 25, 50, and 100 mg/kg. The hydroalcoholic extract of C. depressus has significant antipyretic effect. These results lend support to the popular use of C. depressus in traditional medicine as a remedy for pyrexia and suggest that the characterization of the principles for such activity deserves further investigation.

scholarly journals Effectiveness of medical treatment in overcoming the ureteral double-J stent related symptoms

2012 ◽  
Vol 6 (6) ◽  
pp. 234 ◽  
Author(s):  
Ugur Kuyumcuoglu ◽  
Bilal Eryildirim ◽  
Murat Tuncer ◽  
Gokhan Faydaci ◽  
Fatih Tarhan ◽  
...  
Keyword(s):  
The Body ◽  
Control Group ◽  
Group 4 ◽  
Double J Stent ◽  
Urinary Tract Symptoms ◽  
Stone Treatment ◽  
Group 3 ◽  
Group 5 ◽  
Group 2

Background: We investigated whether the frequency of lower urinary tract symptoms (LUTS) increased in patients in whom double-J stents were applied. We also evaluated several medical therapy protocols to treat symptoms related with ureteral stents.Materials and Methods: A total of 108 patients, in whom unilateral double-j stent was applied during ureteral stone treatment, were included. Before the double-J stent was applied, all patients completed storage components of the “International Prostate Symptom Score” (IPSSs), quality of life components of the IPSS (IPSS-QOL) and “Overactive Bladder Questionnaire” (OABq) forms and scores were calculated. After the procedure, cases were randomized into 5 groups, an antiinflammatory was given to Group 1, spasmolytic to Group 2, anticholinergic to Group 3 and α-blocker to Group 4. No additional drug was given to Group 5 as this control group. During the fourth week of the procedure, IPSSs, IPSS-QOL and OABq forms were again completed and scores were compared with the previous ones.Results: When all the cases were evaluated, the IPSSs, IPSS-QOLand OABq scores of patients in whom the double-J stent was applied were statistically significantly higher the procedure. Compared to the control group, the cases where the double-J stent was applied showed a higher IPSSs, IPSS-QOL and OABq scores and none of the medical therapies could prevent this increase.Interpretation: The frequency of LUTS increased in cases where the ureteral stent was applied and discomfort continued as long as the stent stayed in the body.

scholarly journals Експериментальне зараження поросят вірусом епідемічної діареї свиней

2017 ◽  
Vol 19 (77) ◽  
pp. 208-213
Author(s):  
D. Masiuk ◽  
A. Sosnitskiy ◽  
A. Kokarev ◽  
S. Koliada
Keyword(s):  
Real Time ◽  
The Body ◽  
Control Group ◽  
Rt Pcr ◽  
Internal Organs ◽  
Real Time System ◽  
E Coli ◽  
Neonatal Piglets ◽  
And Control ◽  
Experimental Group

There were infected neonatal piglets in the first days of their lives PED virus suspension derived from pigs previously PED patients. Diagnosis for PED in piglets donor virus PED was inserted complex method for clinical and epizootic performance and confirmed the identification PEDV by PCR-RT using the test system «EZ-RED/TGE/PDCoV MPX 1.0 Real time RT-PCR» company Tetracore (USA) Thermocyclers CFX 96 Real-Time System company BIO RAD (USA). Homogenate small intestine of pigs PEDV donor, prepared in a blender for PCR in a thick band of 18 animal carcasses, frozen at -18 °C without cryopreservation and kept 359 days. Before infecting pigs and strip defrost by RT-PCR identified the concentration of the virus genome equivalents (GE) without establishing viable virions quantitative pathogen. For Sample 20 selected analog neonatal piglets, divided them into 3 experimental groups (group 1 – 5 piglets, group 2 – 5 piglets and group 3 – 7 piglets) and one control (3 piglets). Research pigs infected per os virus-containing suspension with a concentration PEDV 1.03×106 GE/cm3. The dose for infection first group was 6 cm3 (6.18×106 GE/cm3), for the second – 5 cm3 (5,15 × 106 GE/cm3), for the third – 4 cm3 (4.12 GE×106/cm3) homogenate. The fourth group – control (not infected). All the pigs were in identical conditions that fully meet the physiological needs of the body. Of the 17 infected pigs only 2 was infected PEDV. PED was confirmed by laboratory methods. In bacteriological examination of internal organs of pigs that came out of a research experiment and control group were diagnosed colibacteriosis. In the control group was isolated from heart and intestinal non-pathogenic for white mice E. coli. From pigs 1 and 2 research groups has been allocated to white mice nonpathogenic E. coli, is set colibacteriosis; 2 experimental group found in one pig hemolytic E. coli; 3 experimental group from the internal organs of pigs in conjunction with non-pathogenic for mice intestinal former cane isolated Klesiella spp., is diagnosed with mixed infection (E. coli, Klesiella spp.). From the intestine of experimental and control pigs do not identified beneficial microflora – aerococcus, lactobacteria, bifidobacteria and cultured putrefactive anaerobic spore facultative and non spore microflora.

scholarly journals Decontamination of a Diving Suit

2016 ◽  
Vol 57 (4) ◽  
pp. 45-51 ◽  
Author(s):  
Zbigniew Dąbrowiecki ◽  
Małgorzata Dąbrowiecka ◽  
Romuald Olszański ◽  
Piotr Siermontowski
Keyword(s):  
Hydrogen Peroxide ◽  
Protective Clothing ◽  
Fire Department ◽  
Gaseous Hydrogen ◽  
The Body ◽  
Night Vision ◽  
Upper Respiratory Tract ◽  
E Coli ◽  
Fabric Surface ◽  
Micro Organisms

AbstractWhen working in chemical or biological environments, contamination is an extremely dangerous issue for the rescue services of the fire department, police and the army.Modern protective overalls worn by fire fighters or dry “Viking” diving suits made from neoprene or nylon covered with polyurethane, have been proven to ensure sufficient protection. However, once the contaminated area is left, there is a need to perform decontamination of the external and internal surfaces of the protective overalls; in order to ensure the clothing continues to offer a high level of comfort and to retain the durability of said protective clothing, it is of course also necessary to perform a drying procedure.Moreover, there is a risk of a transfer of pathogenic micro-organisms between persons utilising the same protective clothes, particularly in the case of expensive specialist suits. Micro-organisms which may potentially spread through clothing include intestinal bacteria, such as: Salmonella, Shigella, Campylobacter, E. coli (including E. coli O157), C. difficile, viruses inducing infections of the upper respiratory tract and alimentary tract (noraviruses, rotaviruses, adeno and astroviruses). The risk of infection also involves the presence of the flu viruses, herpesviruses and pathogens transferred through skin, such as S. aureus (including MRSA), yeast-like fungi (Candida albicans), fungal strains inducing Tinea pedis and Tinea corporis [1]. Pathogenic micro-organisms can easily transfer from fabric surface onto the body of a person wearing protective clothing.From the numerous available techniques of decontamination of surfaces, equipment and protective clothing we propose to use for this purpose gaseous hydrogen peroxide (H2O2), a very effective biocidal agent. In field conditions, typical for the activities of rescue crews of the fire department, police and army we assume utilisation of a portable decontamination chamber enabling performance of a complete decontamination process.The process lasting approximately 3 hours encompasses 3 phases:• Drying phase;• Decontamination with gaseous hydrogen peroxide;• Catalytic combustion phase of hydrogen peroxide residues to a level safe for the environment.The integrated humidity and H2O2level sensors ensure automatic control of the entire process and the unique distribution system of gaseous H2O2secures full accessibility of the biocidal agent to the external surface of protective clothing as well as its interior. Moreover, the container allows for the conduction of the complete decontamination of the rescue equipment, night vision devices, binoculars, field telephones, radio stations, etc. Upon decontamination cycle completion, we obtain a completely dried suit which can be safely used by another crew member.

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