Immunosensor for rapid extraction/detection of enteric pathogens

TECHNOLOGY ◽  
2016 ◽  
Vol 04 (03) ◽  
pp. 194-200 ◽  
Author(s):  
Evangelyn C. Alocilja ◽  
Parul Jain ◽  
Kasey Pryg
Keyword(s):  
Ease Of Use ◽  
Enteric Pathogens ◽  
Great Promise ◽  
Contamination Level ◽  
Detection Range ◽  
E Coli ◽  
Rapid Extraction ◽  
Redox Active ◽  
Microbial Contaminants ◽  
Food Matrices

An antibody-based sensor (immunosensor) has been developed that features an all-in-one extraction and detection of the enteric pathogen E. coli O57 : H7 using the same redox-active polyaniline-coated iron oxide nanoparticles (PIONs). Capture efficiency for E. coli O57 : H7 is shown to be 81–99% in various food matrices with varying properties. The immunosensor's detection range is 100 to 105 CFU/mL with a detection limit of 5 CFU. Furthermore, magnetic separation is showing great promise as an alternative to existing conventional sample processing systems. Given the bacteria's low contamination level in food and water, this biosensor technology has great potential in monitoring enteric microbial contaminants in the food supply chain where simplicity, sensitivity, and ease of use are important.

Antimicrobial Activity of Silver Nanoparticles Prepared Under an Ultrasonic Field

2011 ◽  
Vol 4 (3) ◽  
pp. 1491-1496
Author(s):  
Umadevi M ◽  
Rani T ◽  
Balakrishnan T ◽  
Ramanibai R
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Therapeutic Potential ◽  
Chemical Reduction ◽  
Ultrasonic Field ◽  
Great Promise ◽  
Chemical Reduction Method ◽  
E Coli

Nanotechnology has great promise for improving the therapeutic potential of medicinal molecules and related agents. In this study, silver nanoparticles of different sizes were synthesized in an ultrasonic field using the chemical reduction method with sodium borohydride as a reducing agent. The size effect of silver nanoparticles on antimicrobial activity were tested against the microorganisms Staphylococcus aureus (MTCC No. 96), Bacillus subtilis (MTCC No. 441), Streptococcus mutans (MTCC No. 497), Escherichia coli (MTCC No. 739) and Pseudomonas aeruginosa (MTCC No. 1934). The results shows that B. subtilis, and E. coli were more sensitive to silver nanoparticles and its size, indicating the superior antimicrobial efficacy of silver nanoparticles. 

scholarly journals The synthesis of novel BODIPY compounds for DSSC applications.

2021 ◽  
Author(s):  
Devin Douglas Machin
Keyword(s):  
Fine Tuning ◽  
Great Promise ◽  
Device Performance ◽  
Dye Molecules ◽  
Dye Sensitized ◽  
Redox Active ◽  
Boron Dipyrromethene ◽  
Photovoltaic Technologies ◽  
Active Donor ◽  
Dye Molecule

The dye-sensitized solar cell (DSSC) represents one of the most promising next-generation photovoltaic technologies. In addition, the DSSC manifold provides an exceptional platform to further appreciate photoinduced electron transfer and the fundamental features required for light-harvesting. The dye molecule is a key component in the DSSC and has achieved minor success utilizing both an organic and inorganic photosensitizers. DSSC’s show great promise owing to their inexpensive synthesis tunable optical and electrochemical properties, and a plethora of design possibilities. The typical anatomy of organic and inorganic DSSC dyes are comprised of a redox-active donor/chromophore (D) that is connected, through a conjugated linker (π), to an acceptor (A) capable of anchoring to titania (TiO2). Fine tuning each of these components can shift the absorption spectrum increasing the overall device efficiency. Boron-dipyrromethene (BODIPY) is an attractive moiety to integrate into DSSC dyes. BODIPY’s rigid organic framework should be able to improve dye stability while the high extinction coefficients of BODIPY based molecules have the potential to increase device performance. Herein, we explore the synthesis and physicochemical properties of BODIPY in an attempt to synthesize efficient DSSC dye molecules and efficient photovoltaic technologies.

scholarly journals Assessing Occupational Exposure to Surface Contaminants in Kuwaiti Educational Buildings

2019 ◽  
Vol 2 (3) ◽  
pp. 1
Author(s):  
Abdul-Salam Al-Temeemi ◽  
Jamal Al-Hubail ◽  
Ahmad Al-Khayat
Keyword(s):  
Architectural Design ◽  
Bacterial Contamination ◽  
Sampling Location ◽  
Contamination Level ◽  
E Coli ◽  
Surface Contaminants ◽  
Microbiological Testing ◽  
Stool Samples ◽  
The State Of Kuwait ◽  
Contamination Problem

The prevalence of surface contaminants, such as potentially harmful bacteria, within building environments in the State of Kuwait is not known.To the authors’ knowledge, this article is the frst of such a report. A total of 342 stool samples were collected from 46 secondary schools to evaluate indoor occurrences of E. coli bacteria within selected lavatory surfaces. After microbiological testing, the results for the spread of the E. coli bacteria were categorized by total count, sampling location dependency, contamination level comparison between genders, and lavatory fxtures (i.e. seat and squat toilets). The results revealed that 7 schools have a bacterial contamination problem, there is cross-contamination between surfaces in the lavatory stalls, the boys’ lavatories were less sanitary than the girls’, and that the squat-style toilets are more contaminated than the seat-style. The results suggest that there is signifcant risk of spread of bacterial infection among students via contaminated hands and surfaces in the lavatory area in some schools. Thus, this study emphasizes the need to improve environmental hygiene and enhanced sanitation in these schools. In addition, conclusions can be drawn as to the effectiveness of the janitorial staff employed by the schools and the effcacy of the cleaning regime used in the lavatories. Furthermore, based on the fndings, there are architectural design consequences as squat-style toilets might be excluded in lavatories designed for schools to be constructed in the future.

scholarly journals Genetic analysis of the role of the conserved inner membrane protein CvpA in EHEC resistance to deoxycholate

2020 ◽  
Author(s):  
Alyson R. Warr ◽  
Rachel T. Giorgio ◽  
Matthew K. Waldor
Keyword(s):  
Stress Response ◽  
Membrane Protein ◽  
Bile Salt ◽  
Cell Envelope ◽  
Enteric Bacteria ◽  
Enteric Pathogens ◽  
Inner Membrane ◽  
Bacterial Phyla ◽  
E Coli ◽  
Inner Membrane Protein

The function of cvpA, a bacterial gene predicted to encode an inner membrane protein, is largely unknown. Early studies in E. coli linked cvpA to Colicin V secretion and recent work revealed that it is required for robust intestinal colonization by diverse enteric pathogens. In enterohemorrhagic E. coli (EHEC), cvpA is required for resistance to the bile salt deoxycholate (DOC). Here, we carried out genome-scale transposon-insertion mutagenesis and spontaneous suppressor analysis to uncover cvpA’s genetic interactions and identify common pathways that rescue the sensitivity of a ΔcvpA EHEC mutant to DOC. These screens demonstrated that mutations predicted to activate the σE-mediated extracytoplasmic stress response bypass the ΔcvpA mutant’s susceptibility to DOC. Consistent with this idea, we found that deletions in rseA and msbB and direct overexpression of rpoE restored DOC resistance to the ΔcvpA mutant. Analysis of the distribution of CvpA homologs revealed that this inner membrane protein is conserved across diverse bacterial phyla, in both enteric and non-enteric bacteria that are not exposed to bile. Together, our findings suggest that CvpA plays a role in cell envelope homeostasis in response to DOC and similar stress stimuli in diverse bacterial species. IMPORTANCE Several enteric pathogens, including Enterohemorrhagic E. coli (EHEC), require CvpA to robustly colonize the intestine. This inner membrane protein is also important for secretion of a colicin and EHEC resistance to the bile salt deoxycholate (DOC), but its function is unknown. Genetic analyses carried out here showed that activation of the σE-mediated extracytoplasmic stress response restored the resistance of a cvpA mutant to DOC, suggesting that CvpA plays a role in cell envelope homeostasis. The conservation of CvpA across diverse bacterial phyla suggests that this membrane protein facilitates cell envelope homeostasis in response to varied cell envelope perturbations.

Acrobeloides buetschlii as a potential vector for enteric pathogens

Nematology ◽  
2015 ◽  
Vol 17 (4) ◽  
pp. 447-457 ◽  
Author(s):  
Yulia Kroupitski ◽  
Riky Pinto ◽  
Patricia Bucki ◽  
Edward Belausov ◽  
Liliane Ruess ◽  
...  
Keyword(s):  
Enteric Pathogens ◽  
Suitable Model ◽  
Human Pathogens ◽  
Relevant Model ◽  
Free Living ◽  
Potential Vector ◽  
E Coli ◽  
Food Borne Pathogens ◽  
Food Borne ◽  
Agricultural Setting

The objective of the present study was to assess ifAcrobeloides buetschlii, an opportunistic species common across many soils, can be employed as a suitable model for interactions between free-living soil nematodes and enteric human pathogens.Acrobeloides buetschliiwas exposed to mCherry-taggedSalmonella entericaandEscherichia coliO157:H7 and its vector potential was assessed.Salmonellacells were more readily ingested by the nematodes compared toE. coliO157:H7. Adult nematodes ingested more bacteria compared to juveniles.Salmonellasurvived internally for at least 7 days without affecting the viability of nematodes. Bacterial ingestion byA. buetschliidid not vary for three testedSalmonellaserovars but was significantly lower forE. coliO157:H7. Considering the ubiquitous nature of pathogen and vector, these findings suggest thatA. buetschliican serve as a relevant model for studying nematode-Salmonellainteractions in an agricultural setting and as potential transport for food-borne pathogens from soil to crops.

Response of hydroperoxidase and superoxide dismutase deficient mutants of Escherichia coli K-12 to oxidative stress

1988 ◽  
Vol 34 (10) ◽  
pp. 1171-1176 ◽  
Author(s):  
Herb E. Schellhorn ◽  
Hosni M. Hassan
Keyword(s):  
Escherichia Coli ◽  
Superoxide Dismutase ◽  
Oxidant Stress ◽  
Relative Importance ◽  
E Coli ◽  
Redox Active ◽  
Chemical Oxidants ◽  
Dependent Growth ◽  
K 12 ◽  
Generalized Transduction

In Escherichia coli, the coordinate action of two antioxidant enzymes, superoxide dismutase and hydroperoxidase (catalase), protect the cell from the deleterious effects of oxyradicals generated during normal aerobic respiration. To evaluate the relative importance of these two classes of enzymes, strains of E. coli deficient in superoxide dismutase and (or) hydroperoxidase were constructed by generalized transduction and their physiological responses to oxygen and oxidant stress examined. Superoxide dismutase was found to be more important than hydroperoxidase in preventing oxygen-dependent growth inhibition and mutagenesis, and in reducing sensitivity to redox-active compounds known to generate the superoxide anion. However, both types of enzymes were required for an effective defense against chemical oxidants that generate superoxide radicals and hydrogen peroxide.

scholarly journals Role of enteric pathogens in the aetiology of neonatal diarrhoea in lambs and goat kids in Spain

1996 ◽  
Vol 117 (1) ◽  
pp. 203-211 ◽  
Author(s):  
M. Muñoz ◽  
M. Álvarez ◽  
I. Lanza ◽  
P. Cármenes
Keyword(s):  
Escherichia Coli ◽  
Synergistic Effect ◽  
Cryptosporidium Parvum ◽  
Clinical Characteristics ◽  
Enteric Pathogens ◽  
E Coli ◽  
Neonatal Diarrhoea ◽  
Group A ◽  
Group B

SummaryFaeces samples from diarrhoeic and non-diarrhoeic lambs and goat kids aged 1–45 days were examined for enteric pathogens.Cryptosporidium parvumwas detected in both diarrhoeic lambs (45%) and goat kids (42%) but not in non-diarrhoeic animals. F5+(K99+) and/or F41+Escherichia colistrains were isolated from 26% and 22% of the diarrhoeic lambs and goat kids, respectively, although these strains, which did not produce enterotoxins ST I or LT I, were found with similar frequencies in non-diarrhoeic animals. A F5−F41−ST I+E. colistrain was isolated from a diarrhoeic lamb (0·6%). VerotoxigenicE. coliwas isolated from both diarrhoeic and non-diarrhoeic lambs (4·1% and 8·2%, respectively) and there was no association between infection and diarrhoea. The prevalence of group A rotavirus infection in diarrhoeic lambs was very low (2·1%). Groups A and B rotaviruses were detected in three (8·1%) and five (13·5%) diarrhoeic goat kids from two single outbreaks. Group C rotaviruses were detected in four non-diarrhoeic goat kids. An association of diarrhoea and infection was demonstrated only for group B rotavirus.Clostridium perfringenswas isolated from 10·8% of the diarrhoeic goat kids but not from non-diarrhoeic goat kids or lambs.Salmonella arizonaewas isolated from a diarrhoeic goat kid (2·7%) and the clinical characteristics of the outbreaks where these two latter enteropathogens were found different from the rest. Picobirnaviruses were detected in a diarrhoeic lamb. No coronaviruses were detected using a bovine coronavirus ELISA. No evidence was found of synergistic effect between the agents studied. Enteric pathogens were not found in four (8·7%) and three (20%) outbreaks of diarrhoea in lambs and goat kids, respectively.

scholarly journals Impact of Ceftiofur Injection on Gut Microbiota and Escherichia coli Resistance in Pigs

2015 ◽  
Vol 59 (9) ◽  
pp. 5171-5180 ◽  
Author(s):  
M. A. Fleury ◽  
G. Mourand ◽  
E. Jouy ◽  
F. Touzain ◽  
L. Le Devendec ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gut Microbiota ◽  
Treated Group ◽  
Conjugative Plasmid ◽  
Health Concern ◽  
Pcr Analysis ◽  
Contamination Level ◽  
Content Type ◽  
E Coli ◽  
The Impact

ABSTRACTResistance to extended-spectrum cephalosporins (ESCs) is an important health concern. Here, we studied the impact of the administration of a long-acting form of ceftiofur on the pig gut microbiota and ESC resistance inEscherichia coli. Pigs were orally inoculated with an ESC-resistantE. coliM63 strain harboring a conjugative plasmid carrying a gene conferring resistance,blaCTX-M-1. On the same day, they were given or not a unique injection of ceftiofur. Fecal microbiota were studied using quantitative PCR analysis of the main bacterial groups and quantification of short-chain fatty acids.E. coliand ESC-resistantE. coliwere determined by culture methods, and the ESC-resistantE. coliisolates were characterized. The copies of theblaCTX-M-1gene were quantified. After ceftiofur injection, the main change in gut microbiota was the significant but transitory decrease in theE. colipopulation. Acetate and butyrate levels were significantly lower in the treated group. In all inoculated groups,E. coliM63 persisted in most pigs, and theblaCTX-M-1gene was transferred to otherE. coli. Culture and PCR results showed that the ceftiofur-treated group shed significantly more resistant strains 1 and 3 days after ESC injection. Thereafter, on most dates, there were no differences between the groups, but notably, one pig in the nontreated group regularly excreted very high numbers of ESC-resistantE. coli, probably leading to a higher contamination level in its pen. In conclusion, the use of ESCs, and also the presence of high-shedding animals, are important features in the spread of ESC resistance.

scholarly journals Surgical-Handling Properties of the Titanium Prosthesis in Ossiculoplasty

2005 ◽  
Vol 84 (3) ◽  
pp. 142-149 ◽  
Author(s):  
Marcus M. Maassen ◽  
Hubert Löwenheim ◽  
Markus Pfister ◽  
Stephan Herberhold ◽  
Jesus Rodriguez Jorge ◽  
...  
Keyword(s):  
Titanium Implant ◽  
Ease Of Use ◽  
Great Promise ◽  
Success Rates ◽  
The Past ◽  
Outcomes Measures ◽  
Handling Characteristics ◽  
The Stability ◽  
Time Required ◽  
Satisfaction Rates

Despite the wide variety of ossiculoplasty techniques that are available, success rates are limited. Current use indicates that surgeons prefer ceramic, autograft bone, and plastic pore prostheses. During the past decade, titanium prostheses have been used with great promise. Although their use is not widespread, satisfaction rates are high. An earlier study of ossiculoplasty showed that titanium prostheses were effective in reducing conductive hearing loss. To date, the surgical-handling attributes of titanium middle ear prostheses have not been assessed. We report the results of our survey of 32 otologic surgeons who used the open Tubingen titanium prosthesis for primary and revision ossiculoplasty during tympanoplasty in 400 patients at 12 academic and nonacademic otolaryngology clinics, most of them in Germany. Because the audiometric efficacy of titanium prostheses has been previously reported, our primary outcomes measures included ease of use with respect to the amount of time required to prepare the implants for placement and the surgeons ‘overall impression of the intraoperative handling characteristics of the implants, taking into consideration factors such as positioning, length adjustment, visibility, and the stability of the coupling. Surgeons also compared the properties of the titanium implant with those of gold, ceramic, and autograft implants that they had used in the past. Based on the results of 383 of the 400 ossiculoplasties, our survey revealed that the titanium implant was significantly superior to the others in all measured respects.

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