scholarly journals An amplification-free ultra-sensitive electrochemical CRISPR/Cas biosensor for drug-resistant bacteria detection

2021 ◽  
Author(s):  
Akkapol Suea-Ngam ◽  
Philip D. Howes ◽  
Andrew J. deMello
Keyword(s):  
Staphylococcus Aureus ◽  
Sensitivity And Specificity ◽  
Bacteria Detection ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Methicillin Resistant ◽  
Drug Resistant Bacteria

An amplification-free electrochemical CRISPR/Cas biosensor utilizing silver metallization (termed E-Si-CRISPR) allows detection of methicillin-resistant Staphylococcus aureus (MRSA) with excellent sensitivity and specificity.

scholarly journals Polymeric approach to combat drug-resistant methicillin-resistant Staphylococcus aureus

2021 ◽  
Vol 56 (12) ◽  
pp. 7265-7285
Author(s):  
Shreya Kanth ◽  
Akshatha Nagaraja ◽  
Yashoda Malgar Puttaiahgowda
Keyword(s):  
Staphylococcus Aureus ◽  
Death Rate ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Pathogenic Microorganisms ◽  
Polymeric Coatings ◽  
Methicillin Resistant ◽  
Drug Resistant Bacteria

Abstract The current global death rate has threatened humans due to increase in deadly unknown infections caused by pathogenic microorganisms. On the contrary, the emergence of multidrug-resistant bacteria is also increasing which is leading to elevated lethality rate worldwide. Development of drug-resistant bacteria has become one of the daunting global challenges due to failure in approaching to combat against them. Methicillin-resistant Staphylococcus aureus (MRSA) is one of those drug-resistant bacteria which has led to increase in global mortality rate causing various lethal infections. Polymer synthesis can be one of the significant approaches to combat MRSA by fabricating polymeric coatings to prevent the spread of infections. This review provides last decade information in the development of various polymers against MRSA. Graphical abstract

scholarly journals Prevalence of resistance phenotypes in Staphylococcus aureus and coagulase-negative isolates of venous ulcers of primary healthcare patients

2012 ◽  
Vol 45 (6) ◽  
pp. 717-722 ◽  
Author(s):  
Marlene Andrade Martins ◽  
Silvana de Lima Vieira dos Santos ◽  
Lara Stefânia Netto de Oliveira Leão ◽  
Nayara Portilho Araújo ◽  
Maria Márcia Bachion
Keyword(s):  
Staphylococcus Aureus ◽  
Primary Healthcare ◽  
Confirmatory Test ◽  
Resistant Bacteria ◽  
Coagulase Negative Staphylococcus ◽  
Drug Resistant ◽  
Methicillin Resistant ◽  
Venous Ulcers ◽  
Drug Resistant Bacteria ◽  
Group Resistance

INTRODUCTION: In venous ulcers, the presence of Staphylococcus aureus and coagulase-negative staphylococcus resistance phenotypes can aggravate and limit the choices for treatment. METHODS: Staphylococcus isolated from 69 patients (98 ulcers) between October of 2009 and October of 2010 were tested. The macrolide, lincosamide, streptogramin B (MLS B) group resistance phenotype detection was performed using the D-test. Isolates resistant to cefoxitin and/or oxacillin (disk-diffusion) were subjected to the confirmatory test to detect minimum inhibitory concentration (MIC), using oxacillin strips (E-test®). RESULTS: The prevalence of S. aureus was 83%, and 15% of coagulase-negative staphylococcus (CoNS). In addition were detected 28% of methicillin-resistant Staphylococcus aureus (MRSA) and 47% of methicillin-resistant coagulase-negative staphylococcus (MRCoNS). Among the S. aureus, 69.6% were resistant to erythromycin, 69.6% to clindamycin, 69.6% to gentamicin, and 100% to ciprofloxacin. Considering the MRSA, 74% were highly resistant to oxacillin, MIC ≥ 256µg/mL, and the MLS Bc constitutive resistance predominated in 65.2%. Among the 20 isolates sensitive to clindamycin, 12 presented an inducible MLS B phenotype. Of the MRCoNS, 71.4%were resistant to erythromycin, ciprofloxacin and gentamicin. Considering the isolates positive for β-lactamases, the MIC breakpoint was between 0.5 and 2µg/mL. CONCLUSIONS: The results point to a high occurrence of multi-drug resistant bacteria in venous ulcers in primary healthcare patients, thus evidencing the need for preventive measures to avoid outbreaks caused by multi-drug resistant pathogens, and the importance of healthcare professionals being able to identifying colonized versus infected venous ulcers as an essential criteria to implementing systemic antibacterial therapy.

scholarly journals All d-Lysine Analogues of the Antimicrobial Peptide HPA3NT3-A2 Increased Serum Stability and without Drug Resistance

2020 ◽  
Vol 21 (16) ◽  
pp. 5632
Author(s):  
Jong-Kook Lee ◽  
Yoonkyung Park
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antimicrobial Peptide ◽  
Proteolytic Enzymes ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Peptide Bonds ◽  
Drug Resistant Bacteria ◽  
Antibiotic Drugs ◽  
Strong Antimicrobial Activity

Novel antibiotic drugs are urgently needed because of the increase in drug-resistant bacteria. The use of antimicrobial peptides has been suggested to replace antibiotics as they have strong antimicrobial activity and can be extracted from living organisms such as insects, marine organisms, and mammals. HPA3NT3-A2 ([Ala1,8] HPA3NT3) is an antimicrobial peptide that is an analogue of the HP (2–20) peptide derived from Helicobacter pylori ribosomal protein L1. Although this peptide was shown to have strong antimicrobial activity against drug-resistant bacteria, it also showed lower toxicity against sheep red blood cells (RBCs) and HaCaT cells compared to HPA3NT3. The l-Lys residues of HPA3NT3-A2 was substituted with d-Lys residues (HPA3NT3-A2D; [d-Lys2,5,6,9,10,15] HPA3NT3-A2) to prevent the cleavage of peptide bonds by proteolytic enzymes under physiological conditions. This peptide showed an increased half-life and maintained its antimicrobial activity in the serum against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) (pathogen). Furthermore, the antimicrobial activity of HPA3NT3-A2D was not significantly affected in the presence of mono- or divalent ions (Na+, Mg2+, Ca2+). Finally, l- or d-HPA3NT3-A2 peptides exhibited the strongest antimicrobial activity against antibiotic-resistant bacteria and failed to induce resistance in Staphylococcus aureus after 12 passages.

scholarly journals Recent Progress in the Detection of Bacteria Using Bacteriophages: A Review

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 845 ◽  
Author(s):  
Jan Paczesny ◽  
Łukasz Richter ◽  
Robert Hołyst
Keyword(s):  
21St Century ◽  
Recent Progress ◽  
Point Of View ◽  
Bacteria Detection ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Application Point ◽  
Drug Resistant Bacteria ◽  
Colony Forming Units ◽  
Recent Developments

Bacteria will likely become our most significant enemies of the 21st century, as we are approaching a post-antibiotic era. Bacteriophages, viruses that infect bacteria, allow us to fight infections caused by drug-resistant bacteria and create specific, cheap, and stable sensors for bacteria detection. Here, we summarize the recent developments in the field of phage-based methods for bacteria detection. We focus on works published after mid-2017. We underline the need for further advancements, especially related to lowering the detection (below 1 CFU/mL; CFU stands for colony forming units) and shortening the time of analysis (below one hour). From the application point of view, portable, cheap, and fast devices are needed, even at the expense of sensitivity.

scholarly journals Synergy between Phage Sb-1 and Oxacillin against Methicillin-Resistant Staphylococcus aureus

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 849
Author(s):  
Kevin Simon ◽  
Wolfgang Pier ◽  
Alex Krüttgen ◽  
Hans-Peter Horz
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Resistant Bacteria ◽  
Positive Interactions ◽  
Bacterial Reduction ◽  
Methicillin Resistant ◽  
Sole Agent ◽  
Drug Resistant Bacteria ◽  
Time Kill ◽  
Hospital Acquired

Methicillin-resistant Staphylococcus aureus (MRSA) is a notorious pathogen responsible for not only a number of difficult-to-treat hospital-acquired infections, but also for infections that are community- or livestock-acquired. The increasing lack of efficient antibiotics has renewed the interest in lytic bacteriophages (briefly phages) as additional antimicrobials against multi-drug resistant bacteria, including MRSA. The aim of this study was to test the hypothesis that a combination of the well-known and strictly lytic S. aureus phage Sb-1 and oxacillin, which as sole agent is ineffective against MRSA, exerts a significantly stronger bacterial reduction than either antimicrobial alone. Eighteen different MRSA isolates and, for comparison, five MSSA and four reference strains were included in this study. The bacteria were challenged with a combination of varying dosages of the phage and the antibiotic in liquid medium using five different antibiotic levels and four different viral titers (i.e., multiplicity of infections (MOIs) ranging from 10−5 to 10). The dynamics of the cell density changes were determined via time-kill assays over 16 h. Positive interactions between both antimicrobials in the form of facilitation, additive effects, or synergism were observed for most S. aureus isolates. These enhanced antibacterial effects were robust with phage MOIs of 10−1 and 10 irrespective of the antibiotic concentrations, ranging from 5 to 100 µg/mL. Neutral effects between both antimicrobials were seen only with few isolates. Importantly, antagonism was a rare exception. As a conclusion, phage Sb-1 and oxacillin constitute a robust heterologous antimicrobial pair which extends the efficacy of a phage-only approach for controlling MRSA.

Synthesis Ruthenium complexes Functionalized with Benzothiophene and their Antibacterial activity against Staphylococcus aureus

2021 ◽  
Author(s):  
Xiangwen Liao ◽  
lianghong liu ◽  
yanhui Tan ◽  
guijuan jiang ◽  
haihong fang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Mode Of Action ◽  
Antimicrobial Agents ◽  
Ruthenium Complexes ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria

New effective antimicrobial agents with novel mode of action are urgently need due to the continued emergence of drug-resistant bacteria. Here, three ruthenium complexes functionalized with benzothiophene: [Ru(phen)2(BTPIP)](ClO4)2 (Ru(II)-1), [Ru(dmp)2(BTPIP)](ClO4)2...

scholarly journals Detection of Drug Susceptible and Resistant Viridans Streptococci spp., Staphylococcus Aureus, Klebsiella Pneumoniae and E.coli in Complete Denture Patients and Visualisation using Scanning Electron Microscopy

2020 ◽  
Author(s):  
Leoney Andonissamy ◽  
Suma Karthigeyan ◽  
Seyed Asharaf Ali
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Resistance ◽  
Klebsiella Pneumoniae ◽  
Oral Cavity ◽  
Antibiotic Sensitivity ◽  
Complete Denture ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria ◽  
Sensitivity Tests

Introduction: The bacteria colonising the oral cavity and the dentures acquire drug resistance due to frequent usage of antibiotics systemically and application of mouth rinses and denture disinfectants locally. These multidrug resistant bacteria pose potential threat to the health of the patient as infections caused by them do not respond to conventional antibiotics. Aim: The present study aims at detecting the drug resistant bacteria in patients who wear complete dentures. Materials and Methods: The study is a descriptive study and follows laboratory invitro study design involving 30 complete denture patients. Swabs were collected from their oral cavity as well as complete denture surfaces. Antibiotic sensitivity tests were performed for the following bacteriae namely Viridans streptococci species, Staphylococcus aureus, Klebsiella pneumoniae and E.coli. Isolation of the bacteria were done by means of selective media and subjected to biochemical tests. The 16S rRNA sequencing was done to ascertain the microorganisms by which 20 isolates of each of the selective bacteria were obtained. The bacteria were classified as sensitive, intermediate sensitive and resistant based on antibiotic sensitivity tests. Those isolates which exhibited Multi-Drug Resistance (MDR) were visualised using SEM. Results:Viridans streptococci spp. (40%) and Staphylococcus aureus (25%) isolates were resistant to Amoxiclavulinic acid and Methicilin, whereas Klebsiella pneumoniae (30%) and (30%) E.coli isolates were most resistant to Cefotaxime and Doxicilin. Conclusion: Drug resistant bacteria have been identified from complete dentures and oral cavity in the present study. Antibiotic sensitivity tests, 16S rRNA sequencing and SEM are vital investigative tools to detect and to visualise drug resistant bacteria. Cell density, Extracellular Polymeric Substances (EPS) and capsule could be important factors for providing drug resistance.

scholarly journals Detection of drug resistant bacteria in different ice creams available in local market of Dhaka city

2017 ◽  
Vol 7 (1) ◽  
pp. 33-35
Author(s):  
Md Musa Howlader ◽  
Tahmina Shammi
Keyword(s):  
Staphylococcus Aureus ◽  
Microbiological Quality ◽  
Ice Cream ◽  
Storage Condition ◽  
Resistant Bacteria ◽  
Local Market ◽  
Drug Resistant ◽  
Drug Resistant Bacteria ◽  
Bacteria And Fungi

Sound microbiological quality of ice cream should be ensured for being a widely popular dairy food in the world. Present study was conducted to determine the microbiological quality of different ice cream samples available in Dhaka, Bangladesh. Total 3 ice cream samples were collected and processed to detect the microbiological quality as well as drug resistant trait of the isolates through several conventional Kirby Bauer method. All the samples were found to be contaminated with the total viable bacteria and fungi within the range of 1.2×104 cfu/ml to 4.3×106 cfu/ml. The presence of E. coli, Staphylococcus aureus was also observed up to 104 cfu/ml. However, the fecal contamination was totally absent in all the samples. Antibiotic profile of two isolates was measured against 8 commonly used antibiotics and both E.coli and Staphylococcus aureus were found to be resistant against more than one antibiotics. Appropriate hygienic and storage condition should be maintained concerning the health safety of consumers. Stamford Journal of Microbiology, Vol.7(1) 2017: 33-35

Moxifloxacin derivatives with potential antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA)

2021 ◽  
Vol 21 ◽  
Author(s):  
Rongxing Chen ◽  
Huarui Xue ◽  
Yazhou Xu ◽  
Tianwei Ma ◽  
Yuan Liu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Drug Resistant ◽  
Bacterial Strains ◽  
Topoisomerase Iv ◽  
Methicillin Resistant ◽  
Structure Activity ◽  
Drug Resistant Bacteria ◽  
Mrsa Strains

Background: Methicillin-resistant S. aureus (MRSA) has already tormented humanity and the environment for a long time and is responsible for many difficult-to-treat infections. Unfortunately, there are limited therapeutic options, and MRSA isolates with complete resistance to vancomycin, the first-line drug for the treatment of MRSA infections, have already emerged in recent years. Moxifloxacin retained activity against mutant bacterial strains with various levels of fluoroquinolones resistance and had a lower potential to select for resistant mutants. Isatin is a versatile structure, and its derivatives are potent inhibitors of many enzymes and receptors. The fluoroquinolone-isatin derivatives demonstrated excellent antibacterial activity against both drug-sensitive and drug-resistant organisms. The structure-activity relationship elucidated that incorporation of 1,2,3-triazole moiety into the C-7 position of fluoroquinolone skeleton was favorable to the antibacterial activity. Accordingly, fluoroquinolone derivatives with isatin and 1,2,3-triazole fragments at the side chain on the C-7 position are promising candidates to fight against drug-resistant bacteria. Objective: To explore more active moxifloxacin derivatives to fight against MRSA and enrich the structure-activity relationships. Methods: The synthesized moxifloxacin derivatives 7a-i and 14a-f were evaluated for their antibacterial activity against a panel of MRSA strains by means of standard two-fold serial dilution method. Results: The majority of the synthesized moxifloxacin derivatives were active against most of the tested MRSA strains with MIC values in a range of 1 to 64 μg/mL. The mechanistic investigations revealed that topoisomerase IV was one of the targets for antibacterial activity. Conclusion: These derivatives are useful scaffolds for the development of novel topoisomerase IV inhibitors.

Graphene Oxide Nanosheets with Efficient Antibacterial Activity Against Methicillin-Resistant Staphylococcus aureus (MRSA)

2021 ◽  
Vol 17 (8) ◽  
pp. 1627-1634
Author(s):  
Yujie Gao ◽  
Yuanhao Dong ◽  
Yubin Cao ◽  
Wenlong Huang ◽  
Chenhao Yu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Public Health Problem ◽  
Resistant Bacteria ◽  
Methicillin Resistant ◽  
Antibacterial Performance ◽  
Drug Resistant Bacteria ◽  
Low Concentrations ◽  
Life Threatening

The development of drug-resistant bacteria has become a public health problem, among which methicillin-resistant Staphylococcus aureus (MRSA) leads to various life-threatening diseases. Graphene oxide (GO) is a two-dimensional nanomaterial with potential in the anti-MRSA treatment. This study prepared GO nanosheets with fixed lamellar size, investigated its antibacterial activity against MRSA, and analyzed the related antibacterial mechanisms. We found that the fabrication of GO with stable dispersion was workable. Furthermore, such GO had superior antibacterial performance against MRSA at low concentrations with the dose-dependent anti-MRSA effect. The GO-MRSA interaction also provided fundamental support for the antibacterial mechanisms with cleavage and encapsulation effects. In conclusion, GO nanosheets may be a promising antimicrobial agent against MRSA.

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