scholarly journals NONINVASIVE OPTICAL IMAGING OF STAPHYLOCOCCUS AUREUS INFECTION IN VIVO USING AN ANTIMICROBIAL PEPTIDE FRAGMENT BASED NEAR-INFRARED FLUORESCENT PROBES

2013 ◽  
Vol 06 (03) ◽  
pp. 1350026 ◽  
Author(s):  
CUICUI LIU ◽  
YUEQING GU
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infection ◽  
Antimicrobial Peptide ◽  
Optical Imaging ◽  
Bacterial Infections ◽  
Near Infrared ◽  
Peptide Fragment ◽  
Imaging Probe ◽  
Aureus Infection

The diagnosis of bacterial infections remains a major challenge in medicine. Optical imaging of bacterial infection in living animals is usually conducted with genetic reporters such as light-emitting enzymes or fluorescent proteins. However, there are many circumstances where genetic reporters are not applicable, and there is an urgent need for exogenous synthetic probes that can selectively target bacteria. Optical imaging of bacteria in vivo is much less developed than methods such as radioimaging and MRI. Furthermore near-infrared (NIR) dyes with emission wavelengths in the region of 650–900 nm can propagate through two or more centimeters of tissue and may enable deeper tissue imaging if sensitive detection techniques are employed. Here we constructed an antimicrobial peptide fragment UBI29-41-based near-infrared fluorescent imaging probe. The probe is composed of UBI29-41 conjugated to a near infrared dye ICG-Der-02. UBI29-41 is a cationic antimicrobial peptide that targets the anionic surfaces of bacterial cells. The probe allows detection of Staphylococcus aureus infection (5 × 107 cells) in a mouse local infection model using whole animal near-infrared fluorescence imaging. Furthermore, we demonstrate that the UBI29-41-based imaging probe can selectively accumulate within bacteria. The significantly higher accumulation in bacterial infection suggests that UBI29-41-based imaging probe may be a promising imaging agent to detect bacterial infections.

scholarly journals Real-Time In Vivo Detection and Monitoring of Bacterial Infection Based on NIR-II Imaging

2021 ◽  
Vol 9 ◽  
Author(s):  
Sijia Feng ◽  
Huizhu Li ◽  
Chang Liu ◽  
Mo Chen ◽  
Huaixuan Sheng ◽  
...  
Keyword(s):  
Bacterial Infection ◽  
Real Time ◽  
Bacterial Infections ◽  
Near Infrared ◽  
Imaging System ◽  
Bacterial Load ◽  
Dynamic Imaging ◽  
In Vivo Detection

Treatment according to the dynamic changes of bacterial load in vivo is critical for preventing progression of bacterial infections. Here, we present a lead sulfide quantum dots (PbS QDs) based second near-infrared (NIR-II) fluorescence imaging strategy for bacteria detection and real-time in vivo monitoring. Four strains of bacteria were labeled with synthesized PbS QDs which showed high bacteria labeling efficiency in vitro. Then bacteria at different concentrations were injected subcutaneously on the back of male nude mice for in vivo imaging. A series of NIR-II images taken at a predetermined time manner demonstrated changing patterns of photoluminescence (PL) intensity of infected sites, dynamically imaging a changing bacterial load in real-time. A detection limit around 102–104 CFU/ml was also achieved in vivo. Furthermore, analysis of pathology of infected sites were performed, which showed high biocompatibility of PbS QDs. Therefore, under the guidance of our developed NIR-II imaging system, real-time detection and spatiotemporal monitoring of bacterial infection in vivo can be achieved, thus facilitating anti-infection treatment under the guidance of the dynamic imaging of bacterial load in future.

scholarly journals Contribution of Host Immune Responses Against Influenza D Virus Infection Toward Secondary Bacterial Infection in a Mouse Model

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 994 ◽  
Author(s):  
Raegan M. Skelton ◽  
Kelly M. Shepardson ◽  
Alexis Hatton ◽  
Patrick T. Wilson ◽  
Chithra Sreenivasan ◽  
...  
Keyword(s):  
Immune Responses ◽  
Bacterial Infection ◽  
Bacterial Infections ◽  
Clinical Signs ◽  
A549 Cells ◽  
Host Susceptibility ◽  
Secondary Bacterial Infection ◽  
Aureus Infection

Influenza D viruses (IDV) are known to co-circulate with viral and bacterial pathogens in cattle and other ruminants. Currently, there is limited knowledge regarding host responses to IDV infection and whether IDV infection affects host susceptibility to secondary bacterial infections. To begin to address this gap in knowledge, the current study utilized a combination of in vivo and in vitro approaches to evaluate host cellular responses against primary IDV infection and secondary bacterial infection with Staphylococcus aureus (S. aureus). Primary IDV infection in mice did not result in clinical signs of disease and it did not enhance the susceptibility to secondary S. aureus infection. Rather, IDV infection appeared to protect mice from the usual clinical features of secondary bacterial infection, as demonstrated by improved weight loss, survival, and recovery when compared to S. aureus infection alone. We found a notable increase in IFN-β expression following IDV infection while utilizing human alveolar epithelial A549 cells to analyze early anti-viral responses to IDV infection. These results demonstrate for the first time that IDV infection does not increase the susceptibility to secondary bacterial infection with S. aureus, with evidence that anti-viral immune responses during IDV infection might protect the host against these potentially deadly outcomes.

Garlic Extract (Allium sativum L.) Effectively Inhibits Staphylococcus aureus and Escherichia coli by Invitro Test

2020 ◽  
Vol 2 (2) ◽  
pp. 61-68
Author(s):  
Agnina Listya Anggraini ◽  
Ratih Dewi Dwiyanti ◽  
Anny Thuraidah
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Allium Sativum ◽  
Antibacterial Properties ◽  
Herbal Medicines ◽  
Garlic Extract ◽  
Dilution Method ◽  
Initial Stage

Infection is a disease caused by the presence of pathogenic microbes, including Staphylococcus aureus and Escherichia coli. Garlic (Allium sativum L.) has chemical contents such as allicin, alkaloids, flavonoids, saponins, tannins, and steroids, which can function as an antibacterial against Staphylococcus aureus and Escherichia coli. This study aims to determine the antibacterial properties of garlic extract powder against Staphylococcus aureus and Escherichia coli. This research is the initial stage of the development of herbal medicines to treat Staphylococcus aureus and Escherichia coli infections. The antibacterial activity test was carried out by the liquid dilution method. The concentrations used were 30 mg/mL, 40 mg/mL, 50 mg/mL, 60 mg/mL and 70 mg/mL. The results showed that the Minimum Inhibitory Concentration (MIC) against Staphylococcus aureus and Escherichia coli was 40 mg/mL and 50 mg / mL. Minimum Bactericidal Concentration (MBC) results for Staphylococcus aureus and Escherichia coli are 50 mg/mL and 70 mg/mL. Based on the Simple Linear Regression test, the R2 value of Staphylococcus aureus and Escherichia coli is 0.545 and 0.785, so it can be concluded that there is an effect of garlic extract powder on the growth of Staphylococcus aureus and Escherichia coli by 54.5% and 78.5%. Garlic (Allium sativum L.) extract powder has potential as herbal medicine against bacterial infections but requires further research to determine its effect in vivo.

Models of In-Vivo Bacterial Infections for the Development of Antimicrobial Peptide-based Drugs

2016 ◽  
Vol 17 (5) ◽  
pp. 613-619 ◽  
Author(s):  
Jlenia Brunetti ◽  
Chiara Falciani ◽  
Luisa Bracci ◽  
Alessandro Pini
Keyword(s):  
Antimicrobial Peptide ◽  
Bacterial Infections

scholarly journals Au–ZnO Conjugated Black Phosphorus as a Near-Infrared Light-Triggering and Recurrence-Suppressing Nanoantibiotic Platform against Staphylococcus aureus

Pharmaceutics ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 52
Author(s):  
Atanu Naskar ◽  
Sohee Lee ◽  
Kwang-sun Kim
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Near Infrared ◽  
Au Nanoparticles ◽  
Synthesis Method ◽  
Antibacterial Properties ◽  
Black Phosphorus ◽  
Infrared Light ◽  
Resistant Bacteria ◽  
Near Infrared Light

Antibiotic therapy is the gold standard for bacterial infections treatment. However, the rapid increase in multidrug-resistant (MDR) bacterial infections and its recent use for secondary bacterial infections in many COVID-19 patients has considerably weakened its treatment efficacy. These shortcomings motivated researchers to develop new antibacterial materials, such as nanoparticle-based antibacterial platform with the ability to increase the chances of killing MDR strains and prevent their drug resistance. Herein, we report a new black phosphorus (BP)-based non-damaging near-infrared light-responsive platform conjugated with ZnO and Au nanoparticles as a synergistic antibacterial agent against Staphylococcus aureus species. First, BP nanosheets containing Au nanoparticles were assembled in situ with the ZnO nanoparticles prepared by a low-temperature solution synthesis method. Subsequently, the antibacterial activities of the resulting Au–ZnO–BP nanocomposite against the non-resistant, methicillin-resistant, and erythromycin-resistant S. aureus species were determined, after its photothermal efficacy was assessed. The synthesized nanocomposite exhibited excellent anti-S. aureus activity and good photothermal characteristics. The non-resistant S. aureus species did not produce drug-resistant bacteria after the treatment of multiple consecutive passages under the pressure of the proposed nanoantibiotic, but rapidly developed resistance to erythromycin. This work clearly demonstrates the excellent photothermal antibacterial properties of Au–ZnO–BP nanocomposite against the MDR S. aureus species.

scholarly journals Micelle-based activatable probe for in vivo near-infrared optical imaging of cancer biomolecules

2014 ◽  
Vol 10 (1) ◽  
pp. 187-195 ◽  
Author(s):  
Yoichi Shimizu ◽  
Takashi Temma ◽  
Isao Hara ◽  
Akira Makino ◽  
Ryo Yamahara ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Near Infrared ◽  
Activatable Probe

scholarly journals Assessment of Endothelin-A Receptor Expression in Subcutaneous and Orthotopic Thyroid Carcinoma Xenografts in Vivo Employing Optical Imaging Methods

Endocrinology ◽  
2012 ◽  
Vol 153 (6) ◽  
pp. 2907-2918 ◽  
Author(s):  
Katrin Büther ◽  
Matthijs G. Compeer ◽  
Jo G. R. De Mey ◽  
Otmar Schober ◽  
Michael Schäfers ◽  
...  
Keyword(s):  
Thyroid Carcinoma ◽  
Optical Imaging ◽  
Near Infrared ◽  
Functional Performance ◽  
Thyroid Tumor ◽  
Receptor Expression ◽  
Imaging Methods ◽  
Carcinoma Cell Lines ◽  
Isolated Artery

Endothelin (ET) receptor dysregulation has been described in a number of pathophysiological processes, including cardiovascular disorders, renal failure, and cancer. The aim of this study was to evaluate the expression of the ET-A receptor (ETAR) in murine models of thyroid carcinoma using optical imaging methods. A recently developed near-infrared fluorescent tracer was first assessed in isolated artery preparations for its functional performance in comparison with known ETAR antagonists BQ123 and PD156707. Before evaluation of the tracer in vivo, different thyroid carcinoma cell lines were characterized with respect to their ET receptor expression by RT-PCR and autoradiography. In vivo, sc and orthotopic papillary thyroid tumor xenografts were clearly visualized by fluorescence reflectance imaging and fluorescence-mediated tomography up to 48 h after injection of the tracer. Binding specificity of the probe was demonstrated by predosing with PD156707 as a competing inhibitor. In conclusion, optical imaging with a fluorescent ETAR tracer allows the noninvasive imaging of tumor-associated ETAR expression in vivo. In the future, this technique may help surgeons to evaluate lesion dimensions in intraoperative settings (e.g. thyroidectomy).

scholarly journals Role of Fluorophore Charge on the In Vivo Optical Imaging Properties of Near-Infrared Cyanine Dye/Monoclonal Antibody Conjugates

2015 ◽  
Vol 27 (2) ◽  
pp. 404-413 ◽  
Author(s):  
Kazuhide Sato ◽  
Alexander P. Gorka ◽  
Tadanobu Nagaya ◽  
Megan S. Michie ◽  
Roger R. Nani ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Optical Imaging ◽  
Near Infrared ◽  
Cyanine Dye ◽  
Antibody Conjugates ◽  
Imaging Properties ◽  
In Vivo Optical Imaging

Prevention of Panton-Valentine Toxin-Mediated Leucocyte Destruction Depending on the Ultra-Diluted Staphylococcinum Potency Gradient

2020 ◽  
Vol 33 (02) ◽  
pp. 099-103
Author(s):  
Pritam Goswami ◽  
Sayak Ghosh ◽  
Sk Swaif Ali ◽  
Anamika Basu ◽  
Joydeep Khanra ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Ecological Niche ◽  
Staphylococcal Infection ◽  
Buffy Coat ◽  
Preventive Action ◽  
Phagocytic Cells ◽  
Mortality And Morbidity ◽  
Aureus Infection ◽  
The Mean

Abstract Background Panton-Valentine toxin (PVT) is an important pathological marker of staphylococcal infection mediated by functional as well as morphological damage of the phagocytic cells. Human body being an ecological niche for the bacteria shows higher affinity toward staphylococcal infection. A steady escalation in mortality and morbidity associated with antibiotic resistance in gram-positive infections is an emerging threat all over the globe; thus, it is important to find out an alternative strategy that can diminish the virulence and pathogenicity of the bacteria. Staphylococcin is a colicin-type chemical secreted by Staphylococcus aureus helps to prevent growth of organisms other than its progenitor. In this study, we evaluated the efficacy of homoeopathic medicine Staphylococcinum against staphylococcal PVT at different potencies (6CH, 12CH, 30CH and 200CH). Materials and Methods Different potencies of Staphylococcinum were administered in a leucocyte buffy coat preparation infected with staphylococcal suspension (0.5 McFarland's standard) along with control with alcohol. They were kept in incubator for 2 hours and then centrifuged at 1200 rpm for 5 minutes. Smears prepared on slides with centrifuged deposits stained by Preston and Morrell's modified Gram's method of staining and evaluated under the microscope. Results It was observed that there was extensive destruction of leukocytes in control and 6CH potency, while the degree of destruction decreased markedly from 12CH to 200CH. At 200CH potency, leukocytes were almost normal, which clearly indicate the preventive action of Staphylococcinum against PVT. The mean percentages of intact leucocytes were 0.73, 0.93, 10.00, 27.67 and 65.00 in control, 6CH, 12CH, 30CH and 200CH potencies, respectively. Conclusion The finding may help in the use of this medicine in moribund patients in cases of disseminated S. aureus infection as there is no known side effect of the medicine. However, in vivo study is necessary before such use in those cases.

scholarly journals Staphylococcus aureus Infection of Epidermal Keratinocytes Promotes Expression of Innate Antimicrobial Peptides

2005 ◽  
Vol 73 (8) ◽  
pp. 5241-5244 ◽  
Author(s):  
Barbara E. Menzies ◽  
Aimee Kenoyer
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Human Keratinocytes ◽  
Lipoteichoic Acid ◽  
Epidermal Keratinocytes ◽  
Aureus Infection ◽  
Inflammatory Stimuli ◽  
Peptide Expression ◽  
Antimicrobial Peptide Expression

ABSTRACT Keratinocytes upregulate expression of endogenous antimicrobial peptides in response to inflammatory stimuli. We show that both viable and heat-inactivated Staphylococcus aureus and lipoteichoic acid differentially alter expression of these peptides upon contact with human keratinocytes. The findings indicate a diversity of staphylococcal factors involved in upregulation of antimicrobial peptide expression in cutaneous epithelia.

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