scholarly journals Inactivation of Bacterial Pathogens following Exposure to Light from a 405-Nanometer Light-Emitting Diode Array

2009 ◽  
Vol 75 (7) ◽  
pp. 1932-1937 ◽  
Author(s):  
Michelle Maclean ◽  
Scott J. MacGregor ◽  
John G. Anderson ◽  
Gerry Woolsey
Keyword(s):  
Staphylococcus Aureus ◽  
Light Emitting Diode ◽  
Bacterial Pathogens ◽  
Light Illumination ◽  
Population Densities ◽  
Gram Positive ◽  
Gram Negative ◽  
Light Emitting ◽  
Led Array ◽  
Wide Range

ABSTRACT This study demonstrates the susceptibility of a variety of medically important bacteria to inactivation by 405-nm light from an array of light-emitting diodes (LEDs), without the application of exogenous photosensitizer molecules. Selected bacterial pathogens, all commonly associated with hospital-acquired infections, were exposed to the 405-nm LED array, and the results show that both gram-positive and gram-negative species were successfully inactivated, with the general trend showing gram-positive species to be more susceptible than gram-negative bacteria. Detailed investigation of the bactericidal effect of the blue-light treatment on Staphylococcus aureus suspensions, for a range of different population densities, demonstrated that 405-nm LED array illumination can cause complete inactivation at high population densities: inactivation levels corresponding to a 9-log10 reduction were achieved. The results, which show the inactivation of a wide range of medically important bacteria including methicillin-resistant Staphylococcus aureus, demonstrate that, with further development, narrow-spectrum 405-nm visible-light illumination from an LED source has the potential to provide a novel decontamination method with a wide range of potential applications.

scholarly journals Synthesis, characterization, and in vitro antimicrobial investigation of novel pyran derivatives based on 8-hydroxyquinoline

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Mohamed Rbaa ◽  
Abdelhadi Hichar ◽  
Omar Bazdi ◽  
Younes Lakhrissi ◽  
Khadija Ounine ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Magnetic Resonance ◽  
Penicillin G ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Wide Range

Abstract Background 8-Hydroxyquinoline derivatives are known for their extensive applications in the field of analytical chemistry and separation techniques; their complexes with transition metals also exhibit antibacterial and antifungal activity. Results In the present study, we synthesized a new series of pyranoquinoline derivatives and evaluated their antibacterial activities. The structures of the synthesized compounds were characterized by Fourier transform infrared (FT-IR), hydrogen-1 nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and elemental analysis. All the prepared compounds were evaluated in vitro as antimicrobial agents against Gram-positive and Gram-negative bacterial strains (Escherichia coli (ATCC35218), Staphylococcus aureus (ATCC29213), Vibrio parahaemolyticus (ATCC17802), and Pseudomonas aeruginosa (ATCC27853)). The screening test was determined by using the standard protocol of disc diffusion method (DDM). Conclusion We have synthesized new pyranic compounds bearing an 8-hydroxyquinoline moiety on their structure. The preliminary screening results showed that all the tested compounds have a remarkable inhibitory effect on the growth of the majority of the tested bacterial strains compared to the standard antibiotic (penicillin G), and the chlorinated compound (Q1) is more active against Gram-positive bacteria than Gram-negative bacteria such as the Staphylococcus aureus strain which is the most sensitive. Gram-positive bacteria are responsible for a wide range of infectious diseases, and rising resistance in this group is causing increasing concern. Thus, this study develops novel heterocyclic compound derivatives of 8-hydroxyquinoline that have demonstrated good antibacterial activity against Gram-positive bacteria. Graphical abstract

scholarly journals Bacterial Isolates and Their Antimicrobial Susceptibility Patterns of Wound Infections among Inpatients and Outpatients Attending the University of Gondar Referral Hospital, Northwest Ethiopia

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Aynalem Mohammed ◽  
Mengistu Endris Seid ◽  
Teklay Gebrecherkos ◽  
Moges Tiruneh ◽  
Feleke Moges
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Susceptibility ◽  
Bacterial Pathogens ◽  
Referral Hospital ◽  
Bacterial Isolates ◽  
Gram Positive ◽  
Gram Negative ◽  
Microbiological Methods ◽  
The University ◽  
Susceptibility Patterns

Background.The widespread uses of antibiotics, together with the length of time over which they have been available, have led to the emergence of resistant bacterial pathogens contributing to morbidity and mortality. This study was aimed to assess bacterial isolates and their drug susceptibility patterns from inpatients and outpatients with pus and/or wound discharge.Methods.A cross-sectional study was conducted at the University of Gondar Referral Hospital from March to May, 2014. Wound swab samples were collected from each study participant and inoculated into appropriate media. The bacterial pathogens were identified using standard microbiological methods. Antimicrobial susceptibility tests were performed using disk diffusion technique following Kirby-Bauer method.Results.A total of 137 study subjects were included in the study with bacterial isolation rate of 115 (83.9%). Of all, 81 (59.1%) were males. Seventy-seven (57%) of the isolates were Gram-negative and 59 (43%) were Gram-positive. From the total isolates,Staphylococcus aureuswas the most predominant isolate 39/115 (34%) followed by Klebsiella species (13%), coagulase negative staphylococci spp. (12%) andPseudomonas aeruginosa. Gram-positive isolates were resistant to ampicillin (86.4%), amoxicillin (83%), penicillin (81.3%), oxacillin (74.6%), and tetracycline (59.4%), while Gram-negative isolates were resistant to amoxicillin (97.4%), ampicillin (94.8%), tetracycline (72.7%), trimethoprim/sulfamethoxazole (66%), and chloramphenicol (54.5%).Conclusion. High prevalence of bacterial isolates was found,Staphylococcus aureusbeing the most dominant. High rates of multiple drug resistance pathogens to the commonly used antimicrobial agents were isolated. Therefore, concerned bodies should properly monitor the choice of antibiotics to be used as prophylaxis and empiric treatment in the study area.

scholarly journals LED Rail Signals: Full Hardware Realization of Apparatus with Independent Intensity by Temperature Changes

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1291
Author(s):  
Giuseppe Schirripa Schirripa Spagnolo ◽  
Fabio Leccese
Keyword(s):  
Temperature Sensor ◽  
Energy Efficient ◽  
Light Emitting Diode ◽  
Junction Temperature ◽  
Light Emitting ◽  
Temperature Changes ◽  
Wide Range ◽  
International Regulations ◽  
Long Lifetime ◽  
Set Up

Nowadays, signal lights are made using light-emitting diode arrays (LEDs). These devices are extremely energy efficient and have a very long lifetime. Unfortunately, especially for yellow/amber LEDs, the intensity of the light is closely related to the junction temperature. This makes it difficult to design signal lights to be used in naval, road, railway, and aeronautical sectors, capable of fully respecting national and international regulations. Furthermore, the limitations prescribed by the standards must be respected in a wide range of temperature variations. In other words, in the signaling apparatuses, a system that varies the light intensity emitted according to the operating temperature is useful/necessary. In this paper, we propose a simple and effective solution. In order to adjust the intensity of the light emitted by the LEDs, we use an LED identical to those used to emit light as a temperature sensor. The proposed system was created and tested in the laboratory. As the same device as the ones to be controlled is used as the temperature sensor, the system is very stable and easy to set up.

scholarly journals 1554. Epidemiology of Adult Bacterial Hand Infections at Two Urban Hospitals

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S777-S778
Author(s):  
Arsheena Yassin ◽  
Christine Stavropoulos ◽  
Krystina L Woods ◽  
Jiashan Xu ◽  
Justin Carale ◽  
...  
Keyword(s):  
New York ◽  
Staphylococcus Aureus ◽  
Antibiotic Regimen ◽  
Gram Positive ◽  
Gram Negative ◽  
Streptococcus Species ◽  
Urban Hospitals ◽  
Haemophilus Parainfluenzae ◽  
Empiric Antibiotic ◽  
Gram Negative Organisms

Abstract Background Hand infections represent a major source of morbidity, which can result in hand stiffness and amputation. Early appropriate empiric antibiotic regimen may reduce the associated morbidity, hence the importance to examine local epidemiology. The aim of this study was to define the current epidemiology of adult hand infections at two urban hospitals in New York City. Methods We performed a double center, retrospective study of adult patients hospitalized from March 2018 to May 2020. Patients with positive cultures associated with the hand infections were included. Retrospectively, 100 patients were reviewed. Data on baseline demographic, clinical, surgical, microbiology, and treatment parameters were collected. Results Of the 100 patients, 76% were male, with median age of 47.5 years (35, 58.25) and average C-reactive protein (CRP) of 50.66 mg/L (± 64.64) on admission (see Table 1). Previous hospitalization within 1 year (38%), previous surgical procedures (39%) and recent IV medication use (26%) were common. 130 bacterial isolates were identified (see Table 2). The most frequent organisms were Gram-positive, with Methicillin susceptible Staphylococcus aureus (MSSA, 25.38%), Streptococcus species (20.08%), and Methicillin resistant Staphylococcus aureus (MRSA, 15.38%) being the most common. Gram-negative organisms were infrequent, with Haemophilus parainfluenzae (3.85%), Enterobacter cloacae (3.85) and Pseudomonas aeruginosa (3.08%) being the most prevalent. Of the 100 patients, 27% had polymicrobial infections, associated with trauma (6%), illicit IV use (6%) and unknown (7%) etiologies. Table 1: Baseline demographics and co-morbid conditions Table 2: Types and numbers of organisms in relation to etiologies Conclusion Within our population, the most common organisms associated with hand infections were Gram-positive, with Staphylococcus aureus and Streptococcus species being the most prevalent. Gram-negative pathogens were infrequently isolated. The results within this study can provide guidance to clinicians on assessing the appropriate empiric antibiotic regimen in patients with hand infections, and can serve as a basis for further studies identifying risk factors associated with isolation of organisms associated with hand infections. Disclosures All Authors: No reported disclosures

scholarly journals A Fish Galectin-8 Possesses Direct Bactericidal Activity

2020 ◽  
Vol 22 (1) ◽  
pp. 376
Author(s):  
Tengfei Zhang ◽  
Shuai Jiang ◽  
Li Sun
Keyword(s):  
Bactericidal Activity ◽  
Bacterial Pathogens ◽  
Bactericidal Effect ◽  
Immune Defense ◽  
Carbohydrate Binding ◽  
Dependent Manner ◽  
Animal Cells ◽  
Gram Negative ◽  
Tongue Sole ◽  
Wide Range

Galectins are a family of animal lectins with high affinity for β-galactosides. Galectins are able to bind to bacteria, and a few mammalian galectins are known to kill the bound bacteria. In fish, no galectins with direct bactericidal effect have been reported. In the present study, we identified and characterized a tandem repeat galectin-8 from tongue sole Cynoglossus semilaevis (designated CsGal-8). CsGal-8 possesses conserved carbohydrate recognition domains (CRDs), as well as the conserved HXNPR and WGXEE motifs that are critical for carbohydrate binding. CsGal-8 was constitutively expressed in nine tissues of tongue sole and up-regulated in kidney, spleen, and blood by bacterial challenge. When expressed in HeLa cells, CsGal-8 protein was detected both in the cytoplasm and in the micro-vesicles secreted from the cells. Recombinant CsGal-8 (rCsGal-8) bound to lactose and other carbohydrates in a dose dependent manner. rCsGal-8 bound to a wide range of gram-positive and gram-negative bacteria and was co-localized with the bound bacteria in animal cells. Lactose, fructose, galactose, and trehalose effectively blocked the interactions between rCsGal-8 and different bacteria. Furthermore, rCsGal-8 exerted potent bactericidal activity against some gram-negative bacterial pathogens by directly damaging the membrane and structure of the pathogens. Taken together, these results indicate that CsGal-8 likely plays an important role in the immune defense against some bacterial pathogens by direct bacterial interaction and killing.

Bactericidal activity of disinfectants

2020 ◽  
pp. 13-18
Author(s):  
S. B. Lysko ◽  
M. V. Zadorozhnaya ◽  
O. A. Suntsova
Keyword(s):  
Federal State ◽  
Gram Positive ◽  
Gram Negative ◽  
Development Of Resistance ◽  
Wide Range ◽  
Ammonium Compounds ◽  
C Center ◽  
Test Cultures ◽  
Poultry Farming

The modern market of drugs off ers a wide range of disinfectants. However, the constant use of the same drugs contributes to the development of resistance in the microfl ora and reduces the quality of activities. In this regard to develop eff ective measures to combat and prevent infectious diseases, it is necessary to periodically monitor the activity of disinfectants used in the enterprise. The purpose of the researches was to study the bactericidal eff ect of disinfectants on the microfl ora of poultry enterprises. The researches have been carried out at the Siberian Scientifi c and Research Institute of Poultry Farming – a branch of the Federal State Budgetary Scientifi c Institution “Omsk Agrarian Scientifi c Center”. The activity of 8 disinfectants to 37 test cultures isolated from poultry farms of diff erent productivity trends and species of poultry (chickens, turkeys, quails) has been tested. It has been found as a result of the conducted research that the most expressed bactericidal eff ect on gram-positive and gram-negative microorganisms were complex disinfectants, which included glutaraldehyde in combination with quaternary ammonium compounds. Thus, 1 % solutions of Gludesive and Viroshield provided the death of all test cultures, Dinovis Ultra and TN-4+ – 92 and 84 % of cultures. The disinfecting activity of Mirosan drug and formalin was most expressed for gram-positive microfl ora, among gram-negative microfl ora resistance was registered in 25–75 % and 25–50 % of cultures, respectively. Drugs EcoSide Advansa and Ecocide C have showed the lowest activity to all investigated microorganisms. The largest number of resistant cultures to the tested disinfectants have been registered in the bacteria of the genus Citrobacter spp. and Pseudomonas aeruginosa, while simultaneously noted resistance to 4–6 drugs.

scholarly journals The Development of an Effective Bacterial Single-Cell Lysis Method Suitable for Whole Genome Amplification in Microfluidic Platforms

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 367 ◽  
Author(s):  
Yuguang Liu ◽  
Dirk Schulze-Makuch ◽  
Jean-Pierre de Vera ◽  
Charles Cockell ◽  
Thomas Leya ◽  
...  
Keyword(s):  
Single Cell ◽  
Single Cells ◽  
Bacterial Species ◽  
Cell Manipulation ◽  
Microfluidic Platforms ◽  
Gram Positive ◽  
Gram Negative ◽  
Genome Amplification ◽  
Single Cell Sequencing ◽  
Wide Range

Single-cell sequencing is a powerful technology that provides the capability of analyzing a single cell within a population. This technology is mostly coupled with microfluidic systems for controlled cell manipulation and precise fluid handling to shed light on the genomes of a wide range of cells. So far, single-cell sequencing has been focused mostly on human cells due to the ease of lysing the cells for genome amplification. The major challenges that bacterial species pose to genome amplification from single cells include the rigid bacterial cell walls and the need for an effective lysis protocol compatible with microfluidic platforms. In this work, we present a lysis protocol that can be used to extract genomic DNA from both gram-positive and gram-negative species without interfering with the amplification chemistry. Corynebacterium glutamicum was chosen as a typical gram-positive model and Nostoc sp. as a gram-negative model due to major challenges reported in previous studies. Our protocol is based on thermal and chemical lysis. We consider 80% of single-cell replicates that lead to >5 ng DNA after amplification as successful attempts. The protocol was directly applied to Gloeocapsa sp. and the single cells of the eukaryotic Sphaerocystis sp. and achieved a 100% success rate.

scholarly journals Antimicrobial Activity of Gardenia jasminoides Callus and Crude Leaf Extracts for some Organic Solvents against some Pathogenic Bacteria and Yeasts

2014 ◽  
Vol 8 (3) ◽  
pp. 40-45
Author(s):  
Zina Hashem Shehab ◽  
Huda Suhail Abid ◽  
Sumaya Fadhil Hamad ◽  
Sara Haitham
Keyword(s):  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Pathogenic Bacteria ◽  
Saccharomyces Boulardii ◽  
Gram Negative Bacteria ◽  
Proteus Vulgaris ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Gardenia Jasminoides

The study was conducted to evaluate the inhibitory activity of methanol extract of Gardenia jasminoides leaves compared with leaf crude extracts for some organic solvents namely Methanol, Ethanol, Petroleum ether, Asetone and Chloroform on growth of some pathogenic bacteria and yeast, which included four gram positive isolates Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes and Bacillus cereus and gram negative isolates Escherichia coli, Salmonella typhi, Proteus vulgaris and Pseudomonas aeruginosa and some yeasts Candida albicans and Saccharomyces boulardii, by using well diffusion method. The inhibitory activity of extracts in the tested bacterial strains and yeasts was varied according to the type of extracting solvents and are tested microorganisms. The methanol callus extract which grown on Murashige and Skoog (MS) media by using (Naphthalen acitic acid) NAA and (Benzyle adenine) BA as growth regulator highly effective as compared to the other extracts as for inhibition of three gram positive bacteria and three gram negative bacteria,which include Staphylococcus aureus and, Proteus vulgaris, followed by acetone and ethanolic extracts which include two gram positive bacteria and two gram negative bacteria. All extracts had highly effect in growth of Candida albicans while all crude extracts didn’t show any sensitivity against Saccharomyces boulardii, and when we’d done (High Performance Liquid Chromatography) HPLC test for detection of some active compound we found Quinic acid, Iridiods glycosides and Crocin which its rate in fresh callus was higher than fresh leaves.

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