Polymyxin B-modified conjugated oligomer nanoparticle for targeted identification and enhanced photodynamic antimicrobial therapy

2021 ◽  
Author(s):  
Qi Jiang ◽  
Xinrong Yan ◽  
Dan Jiao ◽  
Jiangyan Zhang ◽  
Yonggang Wu ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Antimicrobial Therapy ◽  
Polymyxin B ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Photodynamic Antimicrobial Therapy

We report a photosensitive polymyxin B-modified conjugated oligomer nanoparticle that integrates the targeted identification and synergistic photodynamic therapy in one treatment against resistant gram-negative bacteria. The study expands the application...

scholarly journals Polymyxin B Nephrotoxicity and Efficacy against Nosocomial Infections Caused by Multiresistant Gram-Negative Bacteria

2003 ◽  
Vol 47 (8) ◽  
pp. 2659-2662 ◽  
Author(s):  
John P. Ouderkirk ◽  
Jill A. Nord ◽  
Glenn S. Turett ◽  
Jay Ward Kislak
Keyword(s):  
Renal Failure ◽  
Renal Function ◽  
Renal Toxicity ◽  
Clinical Information ◽  
Polymyxin B ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Length Of Treatment ◽  
Baseline Renal Function ◽  
Overall Mortality

ABSTRACT Reported rates of nephrotoxicity associated with the systemic use of polymyxins have varied widely. The emergence of infections due to multiresistant gram-negative bacteria has necessitated the use of systemic polymyxin B once again for the treatment of such infections. We retrospectively investigated the rate of nephrotoxicity in patients receiving polymyxin B parenterally for the treatment of infections caused by multiresistant gram-negative bacteria from October 1999 to September 2000. Demographic and clinical information was obtained for 60 patients. Outcome measures of interest were renal toxicity and clinical and microbiologic efficacy. Renal failure developed in 14% of the patients, all of whom had normal baseline renal function. Development of renal failure was independent of the daily and cumulative doses of polymyxin B and the length of treatment but was significantly associated with older age (76 versus 59 years, P = 0.02). The overall mortality was 20%, but it increased to 57% in those who developed renal failure. The organism was cleared in 88% of the patients from whom repeat specimens were obtained. The use of polymyxin B to treat multiresistant gram-negative infections was highly effective and associated with a lower rate of nephrotoxicity than previously described.

scholarly journals Visualizing the Potential Impairment of Polymyxin B to Central Nervous System Through MR Susceptibility-Weighted Imaging

2021 ◽  
Vol 12 ◽  
Author(s):  
Ni Zhang ◽  
Lichong Zhu ◽  
Qiuhong Ouyang ◽  
Saisai Yue ◽  
Yichun Huang ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Polymyxin B ◽  
Susceptibility Weighted Imaging ◽  
Gram Negative Bacteria ◽  
Severe Toxicity ◽  
Gram Negative ◽  
The Impact

Polymyxin B (PMB) exert bactericidal effects on the cell wall of Gram-negative bacteria, leading to changes in the permeability of the cytoplasmic membrane and resulting in cell death, which is sensitive to the multi-resistant Gram-negative bacteria. However, the severe toxicity and adverse side effects largely hamper the clinical application of PMB. Although the molecular pathology of PMB neurotoxicity has been adequately studied at the cellular and molecular level. However, the impact of PMB on the physiological states of central nervous system in vivo may be quite different from that in vitro, which need to be further studied. Therefore, in the current study, the biocompatible ultra-uniform Fe3O4 nanoparticles were employed for noninvasively in vivo visualizing the potential impairment of PMB to the central nervous system. Systematic studies clearly reveal that the prepared Fe3O4 nanoparticles can serve as an appropriate magnetic resonance contrast agent with high transverse relaxivity and outstanding biosafety, which thus enables the following in vivo susceptibility-weighted imaging (SWI) studies on the PMB-treated mice models. As a result, it is first found that the blood-brain barrier (BBB) of mice may be impaired by successive PMB administration, displaying by the discrete punctate SWI signals distributed asymmetrically across brain regions in brain parenchyma. This result may pave a noninvasive approach for in-depth studies of PMB medication strategy, monitoring the BBB changes during PMB treatment, and even assessing the risk after PMB successive medication in multidrug-resistant Gram-negative bacterial infected patients from the perspective of medical imaging.

The Bacteriological Profile of Burn Wound Infections at a Tertiary Burns Center in Nepal

2019 ◽  
Vol 40 (6) ◽  
pp. 838-845 ◽  
Author(s):  
Ojas Jyoti Singh Pujji ◽  
Kiran Kishor Nakarmi ◽  
Basudha Shrestha ◽  
Shankar Man Rai ◽  
Steven Leonard Alexander Jeffery
Keyword(s):  
Traffic Accidents ◽  
Burn Injury ◽  
Road Traffic ◽  
Average Distance ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Wound Infections ◽  
Burn Wound ◽  
Gram Negative

AbstractIn Nepal, burn is the third most common injury after falls and road traffic accidents. Infection is the leading cause of mortality in burn injury. A profile exploring predominant flora and antimicrobial sensitivity is important to facilitate treatment ahead of microbiology results and to aid prevention of multidrug-resistant organisms. The aim of this study was to document epidemiological and bacteriological data of burn wound infections at a tertiary level burns center in Nepal. Samples were collected from January 2017 to May 2017, over a period of 5 months. Patient notes were referred to and information regarding baseline characteristics and burn wound infection data was collected. A total of 76 patients were included in the study during the 5-month period, which resulted in 113 samples being included for review. Females were injured most with burns 70% (n = 53) compared with males 30% (n = 23). Only 6 (8%) of 77 patients lived locally in Kathmandu. The average distance traveled by patients was 233 km (median 208, range 0–765, SD 181). Average TBSA% of burn was 22% (median 20, range 3–50, SD 12). Gram-negative organisms predominated, with Acinetobacter spp. in 42 cases (55%), Pseudomonas aeruginosa in 26 cases (34%), and Enterobacter spp. in 16 cases (21%). Colistin, polymyxin B, and tigecycline were found to be most sensitive covering 108, 98, and 94 organisms. Gram-negative bacteria colonized the majority of burn wounds. Colistin, polymyxin B, and tigecycline were the most sensitive to gram-negative bacteria. Gram-positive Staphylococcus aureus was sensitive most to vancomycin and tigecycline.

scholarly journals Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles for antibacterial photodynamic therapy

2019 ◽  
Vol 18 (5) ◽  
pp. 1147-1155 ◽  
Author(s):  
Rehan Khan ◽  
Melis Özkan ◽  
Aisan Khaligh ◽  
Dönüs Tuncel
Keyword(s):  
Antibacterial Activity ◽  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Water Dispersible ◽  
Gram Positive Bacteria ◽  
High Yields

Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles have the ability to generate singlet oxygen in high yields and exhibit light-triggered antibacterial activity against Gram negative bacteria, E. coli as well as Gram positive bacteria, B. subtilis.

scholarly journals Polymyxin B–modified upconversion nanoparticles for selective detection of Gram-negative bacteria such as Escherichia coli

2020 ◽  
Vol 44 (11-12) ◽  
pp. 756-761
Author(s):  
Yan Qiao ◽  
Hongchao Geng ◽  
Ning Jiang ◽  
Xingqi Zhu ◽  
Chenyi Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Limit Of Detection ◽  
Polymyxin B ◽  
Upconversion Nanoparticles ◽  
Selective Detection ◽  
Gram Negative Bacteria ◽  
Cationic Antimicrobial Peptide ◽  
Gram Negative ◽  
In Vivo Fluorescence Imaging

Upconversion nanoparticles, Yb,Tm,Fe-doped NaYF4 nanoparticles, are synthesized and modified with polymyxin B for the selective detection of Gram-negative bacteria. Polymyxin B, a cyclic cationic antimicrobial peptide which can specifically bind to the lipopolysaccharides of cell wall of Gram-negative bacteria, such as Escherichia coli, is used to target and bind Gram-negative bacteria. The bacteria are then quantified by measuring the fluorescence intensity of the upconversion nanoparticle–bacteria complexes at 801 nm under 980 nm excitation. A limit of detection of 36 CFU/mL is achieved in the detection of Escherichia coli, and Escherichia coli in soybean milk is successfully detected. The limited autofluorescence and photobleaching properties of the upconversion nanoparticles make the proposed method useful for in vivo fluorescence imaging of Gram-negative bacteria.

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