scholarly journals Antibiotic Activity Screened by the Rheology of S. aureus Cultures

Fluids ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 76 ◽  
Author(s):  
Raquel Portela ◽  
Filipe Valcovo ◽  
Pedro L. Almeida ◽  
Rita G. Sobral ◽  
Catarina R. Leal
Keyword(s):  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Growth Curves ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Flow Curves ◽  
Viscosity Profile ◽  
The Impact ◽  
Constant Shear Rate ◽  
Over Time

Multidrug resistant bacteria are one of the most serious public health threats nowadays. How bacteria, as a population, react to the presence of antibiotics is of major importance to the outcome of the chosen treatment. In this study we addressed the impact of oxacillin, a β-lactam, the most clinically relevant class of antibiotics, in the viscosity profile of the methicillin resistant Staphylococcus aureus (MRSA) strain COL. In the first approach, the antibiotic was added, at concentrations under the minimum inhibitory concentration (sub-MIC), to the culture of S. aureus and steady-state shear flow curves were obtained for discrete time points during the bacterial growth, with and without the presence of the antibiotic, showing distinct viscosity progress over time. The different behaviors obtained led us to test the impact of the sub-inhibitory concentration and a concentration that inhibited growth. In the second approach, the viscosity growth curves were measured at a constant shear rate of 10 s−1, over time. The obtained rheological behaviors revealed distinctive characteristics associated to the presence of each concentration of the tested antibiotic. These results bring new insights to the bacteria response to a well-known bacteriolytic antibiotic.

Antimicrobial activity of seven Piper species from Colombian coffee-growing Eco-region against multidrug resistant bacteria

2020 ◽  
Vol 3 (3) ◽  
pp. 33-37
Author(s):  
Oscar M Mosquera ◽  
◽  
Roman Y. Ramirez-Rueda ◽  
Aura M. Blandon ◽  
◽  
...  
Keyword(s):  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Methanolic Extract ◽  
Biological Activities ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Biological Evaluation ◽  
Resistant Bacteria ◽  
Antibacterial Compounds ◽  
Layer Chromatography

Species of Piper genus are known for their numerous biological activities and their diverse phytochemical composition. The object of this work was to evaluate the antibacterial activity of extracts obtained from seven Piperaceae species. Broth microdilution technique was used for biological evaluation and some phytochemical nuclei present in the bioactive extracts were identified by thin layer chromatography and characterization reactions. Among the most important results, it is highlighted the inhibitory effect of the methanolic extract from Piper pesaresanum against Methicillin-resistant Staphylococcus aureus ATTC 43300, with minimum inhibitory concentration of 62.5 μg/mL. Additionally, secondary metabolites such as alkaloids, phenols and flavonoids were detected in this extract. In conclussion, the species P. pesaresanum showed high potential for bioguided search of antibacterial compounds against multidrug resistant S. aureus.

scholarly journals Management of superficial and deep surgical site infection: an international multidisciplinary consensus

2021 ◽  
Author(s):  
Gabriele Sganga ◽  
Mohamed Baguneid ◽  
Pascal Dohmen ◽  
Evangelos J. Giamarellos-Bourboulis ◽  
Emilio Romanini ◽  
...  
Keyword(s):  
Length Of Hospital Stay ◽  
Surgical Site Infections ◽  
Early Discharge ◽  
Multidrug Resistant ◽  
Steering Committee ◽  
Resistant Bacteria ◽  
Modified Delphi ◽  
Hospital Stays ◽  
New Treatment ◽  
The Impact

AbstractSurgical site infections represent a considerable burden for healthcare systems. To obtain a consensus on the impact and future clinical and economic needs regarding SSI management in an era of multidrug resistance. A modified Delphi method was used to obtain consensus among experts from five European countries. The Delphi questionnaire was assembled by a steering committee, verified by a panel of experts and administered to 90 experts in 8 different surgical specialities (Abdominal, Cancer, Cardiac, General surgery, Orthopaedic, Thoracic, Transplant and Vascular and three other specialities (infectious disease, internal medicine microbiology). Respondents (n = 52) reached consensus on 62/73 items including that resistant pathogens are an increasing matter of concern and increase both treatment complexity and the length of hospital stay. There was strong positive consensus on the cost-effectiveness of early discharge (ED) programs, improvement of quality of life with ED and association between increased length of stay and economic burden to the hospital. However, established ED protocols were not widely available in their hospitals. Respondents expressed a positive consensus on the usefulness of antibiotics that allow ED. Surgeons are aware of their responsibility in an interdisciplinary team for the treatment of SSI, and of the impact of multidrug-resistant bacteria in the context of SSI. Reducing the length of hospital stays by applying ED protocols and implementing new treatment alternatives is crucial to reduce harm to patients and costs for the hospital.

Antibiotic adjuvants: a promising approach to combat multidrug resistant bacteria

2021 ◽  
Vol 22 ◽  
Author(s):  
Namita Sharma ◽  
Anil K. Chhillar ◽  
Sweety Dahiya ◽  
Pooja Choudhary ◽  
Aruna Punia ◽  
...  
Keyword(s):  
Drug Targets ◽  
Pathogenic Bacteria ◽  
Antibacterial Agents ◽  
Bacterial Resistance ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibacterial Drugs ◽  
Effective Strategies ◽  
The Impact ◽  
Emergence Of Resistance

The escalating emergence and prevalence of infections caused by multi-drug resistant (MDR) pathogenic bacteria accentuate the crucial need to develop novel and effectual therapeutic strategies to control this threat. Recent past surprisingly indicates a staggering decline in effective strategies against MDR. Different approaches have been employed to minimize the effect of resistance but the question still lingers over the astounding number of drugs already tried and tested to no avail, furthermore, the detection of new drug targets and the action of new antibacterial agents against already existing drug targets also complicate the condition. Antibiotic adjuvants are considered as one such promising approach for overcoming the bacterial resistance. Adjuvants can potentiate the action of generally adopted antibacterial drugs against MDR bacterial pathogens either by minimizing the impact and emergence of resistance or improving the action of antibacterial drugs. This review provides an overview of mechanism of antibiotic resistance, main types of adjuvants and their mode of action, achievements and progression.

scholarly journals Identification of Antimicrobial Compounds from Sandwithia guyanensis-Associated Endophyte Using Molecular Network Approach

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 47 ◽  
Author(s):  
Phuong-Y Mai ◽  
Marceau Levasseur ◽  
Didier Buisson ◽  
David Touboul ◽  
Véronique Eparvier
Keyword(s):  
Antibacterial Activity ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Fungal Endophyte ◽  
Molecular Network ◽  
Antimicrobial Compounds ◽  
Plant Leaves ◽  
Major Health ◽  
Different Parts

The emergence of multidrug resistant bacterial pathogens and the increase of antimicrobial resistance constitutes a major health challenge, leading to intense research efforts being focused on the discovery of novel antimicrobial compounds. In this study, endophytes were isolated from different parts of Sandwithia guyanensis plant (leaves, wood and latex) belonging to the Euphorbiaceae family and known to produce antimicrobial compounds, and chemically characterised using Molecular Network in order to discover novel antimicrobial molecules. One fungal endophyte extract obtained from S. guyanensis latex showed significant antimicrobial activity with Minimal Inhibitory Concentration on methicillin-resistant Staphylococcus aureus at 16 µg/mL. The chemical investigation of this fungus (Lecanicillium genus) extract led to the isolation of 5 stephensiolides compounds, four of which demonstrated antibacterial activity. Stephensiolide I and G showed the highest antibacterial activity on MRSA with a MIC at 4 and 16 µg/mL respectively.

An unexpected discovery toward novel membrane active sulfonyl thiazoles as potential MRSA DNA intercalators

2020 ◽  
Vol 12 (19) ◽  
pp. 1709-1727 ◽  
Author(s):  
Yuan-Yuan Hu ◽  
Juan Wang ◽  
Tie-Jun Li ◽  
Rammohan R Yadav Bheemanaboina ◽  
Mohammad Fawad Ansari ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Antibacterial Agents ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Dna Intercalators ◽  
Dna Targeting ◽  
Drug Resistant Bacteria

Aim: With the increasing emergence of drug-resistant bacteria, the need for new antimicrobial agents has become extremely urgent. This work was to develop sulfonyl thiazoles as potential antibacterial agents. Results & methodology: Novel hybrids of sulfonyl thiazoles were developed from commercial acetanilide and acetylthiazole. Hybrids 6e and 6f displayed excellent inhibitory efficacy against clinical methicillin-resistant Staphylococcus aureus (MRSA) (minimum inhibitory concentration = 1 μg/ml) without obvious toxicity toward normal mammalian cells (RAW 264.7). The combination uses were found to improve the antimicrobial ability. Further preliminary antibacterial mechanism experiments showed that the active molecule 6f could effectively interfere with MRSA membrane and insert into MRSA DNA. Conclusion: Compounds 6e and 6f could serve as potential DNA-targeting templates toward the development of promising antimicrobial agents.

scholarly journals Antimicrobial Activity of Five Apitoxins from Apis mellifera on Two Common Foodborne Pathogens

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 367
Author(s):  
Alexandre Lamas ◽  
Vicente Arteaga ◽  
Patricia Regal ◽  
Beatriz Vázquez ◽  
José Manuel Miranda ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Foodborne Pathogens ◽  
Food Chain ◽  
Pathogenic Bacteria ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Public Health Challenges ◽  
Alternative Agent ◽  
Potential Alternative

Antimicrobial resistance is one of today’s major public health challenges. Infections caused by multidrug-resistant bacteria have been responsible for an increasing number of deaths in recent decades. These resistant bacteria are also a concern in the food chain, as bacteria can resist common biocides used in the food industry and reach consumers. As a consequence, the search for alternatives to common antimicrobials by the scientific community has intensified. Substances obtained from nature have shown great potential as new sources of antimicrobial activity. The aim of this study was to evaluate the antimicrobial activity of five bee venoms, also called apitoxins, against two common foodborne pathogens. A total of 50 strains of the Gram-negative pathogen Salmonella enterica and 8 strains of the Gram-positive pathogen Listeria monocytogenes were tested. The results show that the minimum inhibitory concentration (MIC) values were highly influenced by the bacterial genus. The MIC values ranged from 256 to 1024 µg/mL in S. enterica and from 16 to 32 µg/mL in L. monocytogenes. The results of this study demonstrate that apitoxin is a potential alternative agent against common foodborne pathogens, and it can be included in the development of new models to inhibit the growth of pathogenic bacteria in the food chain.

scholarly journals High Colonization Rate and Heterogeneity of ESBL- and Carbapenemase-Producing Enterobacteriaceae Isolated from Gull Feces in Lisbon, Portugal

2020 ◽  
Vol 8 (10) ◽  
pp. 1487
Author(s):  
Marta Aires-de-Sousa ◽  
Claudine Fournier ◽  
Elizeth Lopes ◽  
Hermínia de Lencastre ◽  
Patrice Nordmann ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Bacterial Species ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant ◽  
Encoding Genes

In order to evaluate whether seagulls living on the Lisbon coastline, Portugal, might be colonized and consequently represent potential spreaders of multidrug-resistant bacteria, a total of 88 gull fecal samples were screened for detection of extended-spectrum β-lactamase (ESBL)- or carbapenemase-producing Enterobacteriaceae for methicillin-resistant Staphylococcus aureus (MRSA) and for vancomycin-resistant Enterococci (VRE). A large proportion of samples yielded carbapenemase- or ESBL-producing Enterobacteriaceae (16% and 55%, respectively), while only two MRSA and two VRE were detected. Mating-out assays followed by PCR and whole-plasmid sequencing allowed to identify carbapenemase and ESBL encoding genes. Among 24 carbapenemase-producing isolates, there were mainly Klebsiella pneumoniae (50%) and Escherichia coli (33%). OXA-181 was the most common carbapenemase identified (54%), followed by OXA-48 (25%) and KPC-2 (17%). Ten different ESBLs were found among 62 ESBL-producing isolates, mainly being CTX-M-type enzymes (87%). Co-occurrence in single samples of multiple ESBL- and carbapenemase producers belonging to different bacterial species was observed in some cases. Seagulls constitute an important source for spreading multidrug-resistant bacteria in the environment and their gut microbiota a formidable microenvironment for transfer of resistance genes within bacterial species.

scholarly journals Susceptibility Assessment of Multidrug Resistant Bacteria to Natural Products

Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582093618
Author(s):  
Essam Hassan Mohamed ◽  
Youssef Saeed Alghamdi ◽  
Salama Mostafa Abdel-Hafez ◽  
Mohamed Mohamed Soliman ◽  
Saad H. Alotaibi ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Syzygium Aromaticum ◽  
Bacterial Strains ◽  
Multidrug Resistant Bacteria ◽  
Scanning Electron Microscope Analysis ◽  
Electron Microscope Analysis ◽  
Holothuria Atra ◽  
Scanning Electron

Objective: The aim of this study was to examine the effect of some natural compounds against multidrug-resistant bacteria. Methods: Forty-three bacterial strains were collected. Disc diffusion and minimum inhibitory concentration (MIC) tests were carried out for natural compounds including quercetin, Acacia nilotica, Syzygium aromaticum, and Holothuria atra. Scanning electron microscope analysis and bacterial DNA apoptosis assays were performed. Results: Staphylococcus aureus strains were resistant to imipenim, ampicillin, and penicillin. Most Escherichia coli strains were resistant to amoxicillin, clavulanat, and ampicillin. Finally, tigecycline was effective with Klebsiella pneumoniae and was resistant to all antibiotics. Only S aromaticum had an antibacterial effect on K pneumoniae. Most S aureus strains were sensitive to S aromaticum, A nilotica, and quercetin. All examined natural extracts had no effect on E coli. Holothuria atra had no effect on any of the strains tested. Minimum inhibitory concentration and minimum bactericidal concentration values for examined plants against S aureus were 6.25 to 12, 1.6 to 3.2, and 9.12 to 18.24 mg/mL, respectively. Syzygium aromaticum was active against K pneumoniae with an MIC of 12.5 mg/mL. Scanning electron microscope analysis performed after 24 and 48 hours of incubation showed bacterial strains with distorted shapes and severe cell wall damage. Syzygium aromaticum, quercetin, and A nilotica showed clear fragmentations of S aureus DNA. Conclusions: Current findings confirmed the beneficial effect of using natural products such as clove (S aromaticum), quercetin, and A nilotica as a promising therapy to overcome multidrug resistant bacteria.

scholarly journals Mortality in Patients With Septic Shock by Multidrug Resistant Bacteria

2017 ◽  
Vol 34 (1) ◽  
pp. 48-54 ◽  
Author(s):  
Stefano Busani ◽  
Giulia Serafini ◽  
Elena Mantovani ◽  
Claudia Venturelli ◽  
Maddalena Giannella ◽  
...  
Keyword(s):  
Septic Shock ◽  
Statistical Significance ◽  
Multidrug Resistant ◽  
Immunoglobulin M ◽  
University Hospital ◽  
Resistant Bacteria ◽  
Sepsis Management ◽  
Risk Of Death ◽  
Increased Risk ◽  
The Impact

Background: Patients with septic shock by multidrug resistant (MDR) microorganism maybe considered a specific population of critical patients at very high risk of death in whom the effects of standard sepsis treatment has never been assessed. The objective of this retrospective analysis was to evaluate the risk factors for 30-day mortality and the impact of sepsis management in patients with septic shock caused by MDR bacteria. Methods: Patients with septic shock by MDR bacteria admitted to the mixed intensive care unit (ICU) of Modena University Hospital during a 6-year period were studied. The clinical and microbiological characteristics and sepsis treatments provided were analyzed and compared between survivors (S) and nonsurvivors (NS) at 30 days after septic shock appearance. Results: Ninety-four patients were studied. All therapeutic interventions applied to patients during their ICU stay did not show statistical significance between S and NS groups, except for administration of immunoglobulin M (IgM) preparation which were provided more frequently in S group ( P < .05). At the multivariate adjusted analysis, preexisting cancer (odds ratio [OR] = 2.965) and Acinetobacter baumannii infections (OR = 3.197) were independently correlated with an increased risk of 30-day mortality, whereas treatment with IgM preparation was protective (OR = 0.283). Conclusions: This retrospective study showed that in patients with septic shock caused by MDR bacteria, history of cancer and infection sustained by A baumannii increase the risk of mortality and that standard sepsis treatments do not seem to provide any protective effect. Adjunctive therapy with IgM preparation seems to be beneficial, but further appropriate studies are needed to confirm the results observed.

scholarly journals Nitrogen Functionalities of Amino-Functionalized Nitrogen-Doped Graphene Quantum Dots for Highly Efficient Enhancement of Antimicrobial Therapy to Eliminate Methicillin-Resistant Staphylococcus aureus and Utilization as a Contrast Agent

2021 ◽  
Vol 22 (18) ◽  
pp. 9695
Author(s):  
Wen-Shuo Kuo ◽  
Ping-Ching Wu ◽  
Chi-Yao Hung ◽  
Chia-Yuan Chang ◽  
Jiu-Yao Wang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Quantum Dots ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Continuous Wave ◽  
Graphene Quantum Dots ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Methicillin Resistant ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

There is an urgent need for materials that can efficiently generate reactive oxygen species (ROS) and be used in photodynamic therapy (PDT) as two-photon imaging contrast probes. In this study, graphene quantum dots (GQDs) were subjected to amino group functionalization and nitrogen doping (amino-N-GQDs) via annealing and hydrothermal ammonia autoclave treatments. The synthesized dots could serve as a photosensitizer in PDT and generate more ROS than conventional GQDs under 60-s low-energy (fixed output power: 0.07 W·cm−2) excitation exerted by a 670-nm continuous-wave laser. The generated ROS were used to completely eliminate a multidrug-resistant strain of methicillin-resistant Staphylococcus aureus (MRSA), a Gram-positive bacterium. Compared with conventional GQDs, the amino-N-GQDs had superior optical properties, including stronger absorption, higher quantum yield (0.34), stronger luminescence, and high stability under exposure. The high photostability and intrinsic luminescence of amino-N-GQDs contribute to their suitability as contrast probes for use in biomedical imaging, in addition to their bacteria tracking and localization abilities. Herein, the dual-modality amino-N-GQDs in PDT easily eliminated multidrug-resistant bacteria, ultimately revealing their potential for use in future clinical applications.

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