scholarly journals Poly Lactic-co-Glycolic Acid-Coated Toluidine Blue Nanoparticles for the Antibacterial Therapy of Wounds

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3394
Author(s):  
Xiaomu Xu ◽  
Bo Liu ◽  
Haiyan Wu ◽  
Yichi Zhang ◽  
Xinyuan Tian ◽  
...  
Keyword(s):  
Toluidine Blue ◽  
Bacterial Infections ◽  
Near Infrared ◽  
Multiple Drug Resistance ◽  
Clinical Applications ◽  
Toxicity Tests ◽  
Wall Structure ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
E Coli

Bacterial infections in wounded skin are associated with high mortality. The emergence of drug-resistant bacteria in wounded skin has been a challenge. Toluidine blue (TB) is a safe and inexpensive photosensitizer that can be activated and used in near-infrared photodynamic therapy to effectively kill methicillin-resistant Staphylococcus aureus (MRSA). However, its aggregation-induced quenching effect largely affects its clinical applications. In this study, TB nanoparticles (NPs) were synthesized using an ultrasound-assisted coating method. Their physicochemical and biological properties were studied and evaluated by scanning electron microscopy and Fourier-transform infrared spectroscopy. The TBNPs had a broad-spectrum antibacterial activity against Gram-positive bacteria (MRSA) and Gram-negative bacteria (E. coli). In addition, MTT, hemolysis, and acute toxicity tests confirmed that TBNPs had good biocompatibility. The TBNPs exhibited a high photodynamic performance under laser irradiation and efficiently killed E. coli and MRSA through generated reactive oxygen species, which destroyed the cell wall structure. The potential application of TBNPs in vivo was studied using an MRSA-infected wound model. The TBNPs could promote wound healing within 7 days, mainly by reducing the inflammation and promoting collagen deposition and granulation tissue formation. In conclusion, the TBNPs offer a promising strategy for clinical applications against multiple-drug resistance.

scholarly journals Patterns of Drug-Resistant Bacteria in a General Hospital, China, 2011–2016

2019 ◽  
Vol 68 (2) ◽  
pp. 225-232 ◽  
Author(s):  
TINGTING MAO ◽  
HUIJUAN ZHAI ◽  
GUANGCAI DUAN ◽  
HAIYAN YANG
Keyword(s):  
General Hospital ◽  
Multiple Drug Resistance ◽  
Polymyxin B ◽  
Resistance Rate ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Drug Resistant ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Drug Resistant Bacteria

Drug-resistant bacteria has been a threat to public life and property. We described the trends and changes in antibiotic resistance of important pathogens in a general hospital in Zhengzhou, China from 2011 to 2016, to control antimicrobial-resistant bacteria in hospital and provide support to clinicians and decision-making departments. Five dominant bacteria were enrolled based on the data from the general hospital during 6 years. The results of antimicrobial susceptibility testing were interpreted according to Clinical and Laboratory Standards Institute (CLSI). From 2011 to 2016, a total of 19,260 strains of bacteria were isolated, of which Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii accounted for 51.98%. The resistance rate of K. pneumoniae and E. coli to carbapenem was less than 15%, but resistance of K. pneumoniae to carbapenems increased with time and resistance of E. coli to meropenem increased. The rate of extended-spectrum beta-lactamase (ESBL) production among K. pneumoniae and E. coli was decreasing. For most antibiotics, the resistance rate of ESBL-positive isolates was higher than that of ESBL-negative isolates, excluding carbapenems and cefoxitin. For S. aureus, the rate of methicillin-resistant S. aureus (MRSA) was stable. Resistance of S. aureus to mostly antibiotics decreased with time. Besides polymyxin B, P. aeruginosa and A. baumannii showed high resistance to other antibiotics. For A. baumannii, the resistance rate to mostly antibiotics was increasing. The bacteria showed high levels of resistance and multiple drug resistance. Continuous surveillance and optimizing the use of antibiotics are essential.

scholarly journals Prevalence of tet(X4) in Escherichia coli From Duck Farms in Southeast China

2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Yu ◽  
Chao-Yue Cui ◽  
Xu Kuang ◽  
Chong Chen ◽  
Min-Ge Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multiple Drug Resistance ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Southeast China ◽  
E Coli ◽  
Polymerase Chain ◽  
Human Infections ◽  
Primary Gene

ObjectivesCarbapenems, colistin, and tigecycline are critically important antibiotics in clinics. After the global appearance of blaNDM and mcr mediating the resistance to carbapenems and colistin, respectively, tigecycline becomes the last-resort drug against severe human infections caused by multidrug-resistant bacteria. Recently, a mobile tigecycline resistance gene tet(X4) has been identified in Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii that causes high resistance to tigecycline and other tetracyclines. In this study, the prevalence of tet(X4) in E. coli isolates from duck and goose farms in Southeast China was identified and characterized.MethodsFeces, soil, sewage, and dust samples were collected from duck and goose farms along with the southeast coast provinces of China. Antimicrobial susceptibility testing and polymerase chain reaction screening were performed to investigate the phenotype and genotype of tigecycline resistance. Conjugation, S1 pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing were used to determine the transferability, genetic location, and the genomic characteristics of tet(X4).ResultsIn total, 1,716 samples were collected, and 16 isolates (0.9%) recovered from Guangdong, Shandong, and Jiangsu were positive for tet(X4) gene with tigecycline minimum inhibitory concentrations ≥16 mg/L. Notably, among these tet(X4)-positive E. coil isolates, seven of them were from the environment samples (soil and sewage). PFGE and multilocus sequence typing demonstrated that ST3997 was the most prevalent sequence type (eight isolates, 50%) in Jiangsu province. By conjugation assays, 11 isolates were able to transfer tet(X4) plasmid to E. coli C600 recipient, and these plasmids belonged to IncHI1 and IncX1 detected by sequence analysis. tet(X4) was found adjacent to an insertion sequence ISCR2 downstream and a catD gene upstream for all isolates. In addition, multiple-drug resistance to tigecycline, chlortetracycline, ampicillin, florfenicol, ciprofloxacin, gentamicin, trimethoprim/sulfamethoxazole, and fosfomycin was profiled in most of the tet(X4)-positive isolates.ConclusionThe identification of tet(X4) harboring E. coli strains in duck farms and their surrounding environment enlarges our knowledge of the variety and prevalence of tigecycline resistance. The prevalence of tet(X4) raises concern for the use of tetracyclines in animal farming, and the tet(X4) gene should be listed as primary gene for resistance surveillance.

scholarly journals Microbiological Quality and Antibiogram of E. coli, Salmonella and Vibrio of Salad and Water from Restaurants of Chittagong

2012 ◽  
Vol 5 (1) ◽  
pp. 159-166 ◽  
Author(s):  
T Nawas ◽  
RM Mazumdar ◽  
S Das ◽  
MN Nipa ◽  
S Islam ◽  
...  
Keyword(s):  
Multiple Drug Resistance ◽  
Microbiological Quality ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Antibiotic Resistant Bacteria ◽  
Salmonella Spp ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Vibrio Spp

The study aimed at examining the microbial quality of restaurant salad and the water used for salad preparation and their role as a source of antibiotic resistant bacteria. Samples were collected from 15 different restaurants located in Chittagong city. The range of Total Viable Count was 1.86×104 to7.28×105 CFU/g and 1.60×104 CFU/ml to 4.38×105 CFU/ml for salad and water respectively. Total colifrm and fecal coliform count > 1100 CFU/100 ml were found in 73.33% of salad and 33.33% water samples. Salmonella spp was present in 46.67% of restaurants salad and water. Vibrio spp. was present in 66.67% of salad and  53.33% of water. A total of 102 isolates belonging to genus Vibrio, Salmonella and E. coli were subjected to antibiotic sensitivity test by disc diffusion method by using nine different types of antibiotic discs. Salmonella spp. from salad and water showed resistance against Amoxicillin (75%), Cephradine and Cephalexin (68.75%). 85.71% Vibrio spp. isolated from salad and water were resistant to Amoxicillin respectively. Multiple drug resistance was seen in 39 and 51 isolates of Salmonella and Vibrio isolates, respectively. The results suggest the necessity to follow the hygienic practices in salad preparation and salad might have  an important role as a source of multiple antibiotic resistant bacteria. DOI: http://dx.doi.org/10.3329/jesnr.v5i1.11571 J. Environ. Sci. & Natural Resources, 5(1): 159 - 166, 2012

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.

Antibiotic susceptibility testing of bacteria in drinking water sources in Akungba‐Akoko, Ondo State, Nigeria

2011 ◽  
Vol 1 (4) ◽  
pp. 233-237
Author(s):  
A. O. Ajayi ◽  
N. F. Agangan
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Multiple Drug Resistance ◽  
Antibiotic Sensitivity ◽  
Water Sources ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Antibiotic Resistant ◽  
Antibiotic Sensitivity Test ◽  
The University

In present investigation, the bacteriological analysis and antibiotic sensitivitypattern of drinking water samples collected from different sources ofAkungba Ã¢â‚¬ÂAkoko, Nigeria was done. The antibiotics mainly considered in ourstudy for determining the sensitivity were amongst the commonly used inthis area for treatment of infectious diseases. As a result, the bacteriologicalindex, especially coliform count was observed notably high with 72 x10 1 cfu/ml for stream sample and 26.4 x 10 1 cfu/ml for borehole sample. The majorbacterial isolates identified in the water samples were Staphylococcus sp,E.coli  Ã¢â‚¬Ânegative bacteria wereobserved showing 75% and 65% resistant to Septrin and Amoxicillin respectively.Also, multiple drug resistance was observed for many antibiotics.Therefore, the presence of high amount antibiotic resistant bacteria of clinicalimportance is reported in these water sources which are usually consumedby students and members of the University community. Hence, thisstudy necessitates the need for water treatment so that epidemics of waterbornebacterial disease can be averted in this region., Klebsiella sp, Pseudomonas sp., Enterococcus sp., Bacillus cereus andothers. With regards to the antibiotic sensitivity test, all isolates showed100% resistance to Ampicillin and Cloxacillin and 85.7% resistance to Zinnacef[a cephalosporin product]. However, the gram 

scholarly journals Bacteriophages: the possible solution to treat infections caused by pathogenic bacteria

2017 ◽  
Vol 63 (11) ◽  
pp. 865-879 ◽  
Author(s):  
Ayman El-Shibiny ◽  
Salma El-Sahhar
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Phage Therapy ◽  
Multidrug Resistant ◽  
Clinical Applications ◽  
Western World ◽  
Resistant Bacteria ◽  
Vaccine Production ◽  
Bacterial Populations ◽  
Antibiotic Resistant

Since their discovery in 1915, bacteriophages have been used to treat bacterial infections in animals and humans because of their unique ability to infect their specific bacterial hosts without affecting other bacterial populations. The research carried out in this field throughout the 20th century, largely in Georgia, part of USSR and Poland, led to the establishment of phage therapy protocols. However, the discovery of penicillin and sulfonamide antibiotics in the Western World during the 1930s was a setback in the advancement of phage therapy. The misuse of antibiotics has reduced their efficacy in controlling pathogens and has led to an increase in the number of antibiotic-resistant bacteria. As an alternative to antibiotics, bacteriophages have become a topic of interest with the emergence of multidrug-resistant bacteria, which are a threat to public health. Recent studies have indicated that bacteriophages can be used indirectly to detect pathogenic bacteria or directly as biocontrol agents. Moreover, they can be used to develop new molecules for clinical applications, vaccine production, drug design, and in the nanomedicine field via phage display.

Characterization of novel ybjG and dacC variants in Escherichia coli

2013 ◽  
Vol 62 (11) ◽  
pp. 1728-1734 ◽  
Author(s):  
Dongguo Wang ◽  
Enping Hu ◽  
Jiayu Chen ◽  
Xiulin Tao ◽  
Katelyn Gutierrez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
The Novel ◽  
Conventional Pcr ◽  
E Coli ◽  
Novel Variants ◽  
Restriction Sites ◽  
Genetic Structures

A total of 69 strains of Escherichia coli from patients in the Taizhou Municipal Hospital, China, were isolated, and 11 strains were identified that were resistant to bacitracin, chloramphenicol, tetracycline and erythromycin. These strains were PCR positive for at least two out of three genes, ybjG, dacC and mdfA, by gene mapping with conventional PCR detection. Conjugation experiments demonstrated that these genes existed in plasmids that conferred resistance. Novel ybjG and dacC variants were isolated from E. coli strains EC2163 and EC2347, which were obtained from the sputum of intensive care unit patients. Genetic mapping showed that the genes were located on 8200 kb plasmid regions flanked by EcoRI restriction sites. Three distinct genetic structures were identified among the 11 PCR-positive strains of E. coli, and two contained the novel ybjG and dacC variants. The putative amino acid differences in the ybjG and dacC gene variants were characterized. These results provide evidence for novel variants of ybjG and dacC, and suggest that multiple drug resistance in hospital strains of E. coli depends on the synergistic function of ybjG, dacC and mdfA within three distinct genetic structures in conjugative plasmids.

scholarly journals Fatty Acids-Enriched Fractions of Hermetia illucens (Black Soldier Fly) Larvae Fat Can Combat MDR Pathogenic Fish Bacteria Aeromonas spp.

2021 ◽  
Vol 22 (16) ◽  
pp. 8829
Author(s):  
Heakal Mohamed ◽  
Elena Marusich ◽  
Yuriy Afanasev ◽  
Sergey Leonov
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Multiple Drug Resistance ◽  
Bioactive Molecules ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
High Dose ◽  
Fish Pathogens ◽  
Hermetia Illucens ◽  
Fish Bacteria

Aeromonas spp. cause many diseases in aquaculture habitats. Hermetia illucens (Hi) larvae were used as feed-in aquacultures and in eradicating pathogenic fish bacteria. In the present study, we applied consecutive extractions of the same biomass of BSFL fat using the acidic water–methanol solution. The major constituents of the sequential extracts (SEs) were free fatty acids (FFAs), and fatty acids derivatives as identified by gas chromatography spectrometry (GC-MS). Our improved procedure enabled gradual enrichment in the unsaturated fatty acids (USFAs) content in our SEs. The present study aimed to compare the composition and antimicrobial properties of SEs. Among actual fish pathogens, A. hydrophila and A. salmonicida demonstrated multiple drug resistance (MDR) against different recommended standard antibiotics: A. salmonicida was resistant to six, while A. hydrophila was resistant to four antibiotics from ten used in the present study. For the first time, we demonstrated the high dose-dependent antibacterial activity of each SE against Aeromonas spp., especially MDR A. salmonicida. The bacteriostatic and bactericidal (MIC/MBC) activity of SEs was significantly enhanced through the sequential extractions. The third sequential extract (AWME3) possessed the highest activity against Aeromonas spp.: inhibition zone diameters were in the range (21.47 ± 0.14–20.83 ± 0.22 mm) at a concentration of 40 mg/mL, MIC values ranged between 0.09 and 0.38 mg/mL for A. hydrophila and A. salmonicida, respectively. AWME3 MBC values recorded 0.19 and 0.38 mg/mL, while MIC50 values were 0.065 ± 0.004 and 0.22 ± 0.005 mg/mL against A. hydrophila and A. salmonicida, respectively. Thus, the larvae fat from Hermitia illucens may serve as an excellent reservoir of bioactive molecules with good capacity to eradicate the multidrug-resistant bacteria, having promising potential for practical application in the aquaculture field.

scholarly journals Antibiotic Resistance of Escherichia Coli Isolated from Lake Nainital, Uttarakhand State, India

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Neha Giri ◽  
Anchal Lodhi ◽  
Devendra Singh Bisht ◽  
Suvarna Bhoj ◽  
Deepak Kumar Arya
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multiple Drug Resistance ◽  
Health Concern ◽  
Penicillin G ◽  
Resistant Bacteria ◽  
Sample Collection ◽  
E Coli ◽  
Mar Index ◽  
Collection Sites

Researchers have encountered new challenges with the discovery of multiple drug resistance in microbes. Currently, multidrug resistant bacteria are considered a major public health concern and an emerging global epidemic. Presence of Escherichia coli in water is used as a faecal pollution measure. In this study E. coli isolates were collected from 20 sample collection sites at Lake Nainital. 20 E. coli isolates, 1 from each sample collection sites, were examined for their antibiotic response patterns against a panel of widely used 15 antibiotics. The result of this study showed 100% resistance to Penicillin G followed by Erythromycin (80%). All isolates (100%) were found susceptible for Gentamycin. The susceptibilities for Chloramphenicol and Co-trimoxazaole were found next to Gentamycin as 90 and 85% respectively. Multiple antibiotic resistance (MAR) index was also determined. 0.73 MAR index was observed as highest in 1 isolate. 13 out of 20 isolates had more than 0.2 MAR indices. The result reveals the origin of E. coli isolates from an area of high antibiotics use.

scholarly journals A Simple Assay to Screen Antimicrobial Compounds Potentiating the Activity of Current Antibiotics

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Junaid Iqbal ◽  
Ruqaiyyah Siddiqui ◽  
Shahana Urooj Kazmi ◽  
Naveed Ahmed Khan
Keyword(s):  
Aqueous Extract ◽  
Bacterial Infections ◽  
Juglans Regia ◽  
Tree Bark ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Drug Resistant ◽  
Antimicrobial Compounds ◽  
Drug Resistant Bacteria ◽  
Multiple Drug Resistant

Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract ofJuglans regiatree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract ofJ. regiabark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria,Salmonella typhior enteropathogenicE. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (>30%) in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action ofJ. regiaextract against multiple drug-resistant bacteria when tested with a range of antibiotics.

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